ARTICLE 1 SOURCE: http://en.wikipedia.org/wiki/Pollution Pollution From Wikipedia, the free encyclopedia Air pollution from World War II production. Pollution is the introduction of contaminants into an environment due to human activity that causes harm or discomfort to humans or other living organisms, or damage the environment. Pollution can be in the form of chemical substances, or energy such as noise, heat, or light. Pollutants can be naturally occurring substances or energies, but are considered contaminants when in excess of natural levels. Pollution is often categorized into point source and nonpoint source pollution. Pollution control Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution controls the undesirable waste products from human consumption, industrial production, agricultural activities, mining, transportation and other sources will accumulate or disperse and degrade the natural environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control.
Transcript
ARTICLE 1
SOURCE: http://en.wikipedia.org/wiki/Pollution
Pollution
From Wikipedia, the free encyclopedia
Air pollution from World War II production.
Pollution is the introduction of contaminants into an environment due to human activity that causes harm or discomfort to humans or other living organisms, or damage the environment. Pollution can be in the form of chemical substances, or energy such as noise, heat, or light. Pollutants can be naturally occurring substances or energies, but are considered contaminants when in excess of natural levels. Pollution is often categorized into point source and nonpoint source pollution.
Pollution control
Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution controls the undesirable waste products from human consumption, industrial production, agricultural activities, mining, transportation and other sources will accumulate or disperse and degrade the natural environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control.
Sewage treatment and Wastewater treatment o API oil-water separators[2][3]
o Sedimentation (water treatment)o Dissolved air flotation (DAF)o Activated sludge biotreaterso Biofilterso Powdered activated carbon treatment
Vapor recovery systems
Major forms of pollution and major polluted areas
The major forms of pollution are listed below along with the particular pollutants relevant to each of them:
Air pollution, the release of chemicals and particulates into the atmosphere. Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight.
Water pollution via runoff, leaching to groundwater, liquid spills, wastewater discharges, eutrophication and littering.
Soil contamination occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE[4], herbicides, pesticides and chlorinated hydrocarbons.
Radioactive contamination, added in the wake of 20th century discoveries in atomic physics. (See alpha emitters and actinides in the environment.)
Noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.
Light pollution, includes light trespass, over-illumination and astronomical interference.
Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.
Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.
The Blacksmith Institute issues annually a list of the world's worst polluted places. In the 2007 issues the ten top nominees are located in Azerbaijan, China, India, Peru, Russia, Ukraine and Zambia.
Sources and causes
Motor vehicle emissions are one of the leading causes of air pollution. China, United States, Russia, Mexico, and Japan are the world leaders in air pollution emissions; however, Canada is the number two country, ranked per capita. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries,[3] petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms (dairy cows, pigs, poultry, etc.), PVC factories, metals production factories, plastics factories, and other heavy industry.
Some of the more common soil contaminants are chlorinated hydrocarbons (CFH), heavy metals (such as chromium, cadmium--found in rechargeable batteries, and lead--found in lead paint, aviation fuel and still in some countries, gasoline), MTBE, zinc, arsenic and benzene. Ordinary municipal landfills are the source of many chemical substances entering the soil environment (and often groundwater), emanating from the wide variety of refuse accepted, especially substances illegally discarded there, or from pre-1970 landfills that may have been subject to little control in the U.S. or EU. There have also been some unusual releases of polychlorinated dibenzodioxins, commonly called dioxins for simplicity, such as TCDD.[8]
Pollution can also be the consequence of a natural disaster. For example, hurricanes often involve water contamination from sewage, and petrochemical spills from ruptured boats or automobiles. Larger scale and environmental damage is not uncommon when coastal oil rigs or refineries are involved. Some sources of pollution, such as nuclear power plants or oil tankers, can produce widespread and potentially hazardous releases when accidents occur.
In the case of noise pollution the dominant source class is the motor vehicle, producing about ninety percent of all unwanted noise worldwide.
Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory disease, cardiovascular disease, throat inflammation, chest pain, and congestion. Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. Oil spills can cause skin irritations and rashes. Noise pollution induces hearing loss, high blood pressure, stress, and sleep disturbance.
Ecosystems
Sulfur dioxide and oxides of nitrogen can cause acid rain which reduces the pH value of soil.
Soil can become infertile and unsuitable for plants. This will affect other organisms in the food web.
Smog and haze can reduce the amount of sunlight received by plants to carry out photosynthesis.
Invasive species can out compete native species and reduce biodiversity. Invasive plants can contribute debris and biomolecules (allelopathy) that can alter soil and chemical compositions of an environment, often reducing native species competitiveness.
Biomagnification describes a situation where toxins may be pass through trophic levels, becoming exponentially more concentrated in the process.
Regulation and monitoring
To protect the environment from the adverse effects of pollution, many nations worldwide have enacted legislation to regulate various types of pollution as well as to mitigate the adverse effects of pollution.
Regulation and monitoring by region
International
The Kyoto Protocol[9] is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), an international treaty on global warming. It also reaffirms sections of the UNFCCC. Countries which ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases.[9] A total of 141 countries have ratified the agreement. Notable exceptions include the United States and Australia, who have signed but not ratified the agreement. The stated reason for the United States not ratifying is the exemption of large emitters of greenhouse gases who are also developing countries, like China and India.[10]
An UN environmental conference held in Bali 3 - 14 December 2007 with the participation from 180 countries aims to replace the Kyoto Protocol, which will end in 2012. During the first day of the conference USA, Saudi Arabia and Canada were presented with the "Fossil-of-the-day-award", a symbolic bag of coal for their negative impact on the global climate. The bags included the flags of the respective countries. [11]
China
China's rapid industrialization has substantially increased pollution. China has some relevant regulations: the 1979 Environmental Protection Law, which was largely modelled on U.S. legislation. But the environment continues to deteriorate.[12] Twelve years after the law, only one Chinese city was making an effort to clean up its water discharges.[13] This indicates that China is about 30 years behind the U.S. schedule of environmental regulation and 10 to 20 years behind Europe. In July 2007, it was reported that the World Bank reluctantly censored a report revealing that 750,000 people in China die every year as a result of pollution-related diseases. China's State Environment Protection Agency and the Health Ministry asked the World Bank to cut the calculations of premature deaths from the report fearing the revelation would provoke "social unrest".[14]
Europe
The United Kingdom
In the 1840s, the United Kingdom brought onto the statute books legislation to control water pollution. It was extended to all rivers and coastal water by 1961. However, currently the clean up of historic contamination is controlled under a specific statutory scheme found in Part IIA of the Environmental Protection Act 1990 (Part IIA), as inserted by the Environment Act 1995, and other ‘rules’ found in regulations and statutory guidance. The Act came into force in England in April 2000.
Within the current regulatory framework, Pollution Prevention and Control (PPC) is a regime for controlling pollution from certain industrial activities. The regime introduces the concept of Best Available Techniques ("BAT") to environmental regulations. Operators must use the BAT to control pollution from their industrial activities to prevent, and where that is not practicable, to reduce to acceptable levels, pollution to air, land and water from industrial activities. The Best Available Techniques also aim to balance the cost to the operator against benefits to the environment. The system of Pollution Prevention and Control is replacing that of Integrated Pollution Control (IPC) (which was established by the Environmental Protection Act 1990) and is taking effect between 2000 and 2007. The Pollution Prevention and Control regime implements the European Directive (EC/96/61) on integrated pollution prevention and control.
The United States Environmental Protection Agency (EPA) established threshold standards for air pollutants to protect human health on January 1, 1970. One of the ratings chemicals are given is carcinogenicity. In addition to the classification "unknown", designated levels range from non-carcinogen, to likely and known carcinogen. Some scientists have said that the concentrations which most of these levels indicate are far too high and the exposure of people should be less. In 1999, the United States EPA replaced the Pollution Standards Index (PSI) with the Air Quality Index (AQI) to incorporate new PM2.5 and Ozone standards.
The United States Congress passed the Clean Air Act in 1963 to legislate the reduction of smog and atmospheric pollution in general. That legislation has subsequently been amended and extended in 1966, 1970, 1977 and 1990. Numerous state and local governments have enacted similar legislation either implementing or filling in locally important gaps in the national program. The national Clean Air Act and similar state legislative acts have led to the widespread use of atmospheric dispersion modeling[15] in order to analyze the air quality impacts of proposed major actions.
Passage of the Clean Water Act amendments of 1977 required strict permitting for any contaminant discharge to navigable waters, and also required use of best management practices for a wide range of other water discharges including thermal pollution.
Passage of the Noise Control Act established mechanisms of setting emission standards for virtually every source of noise including motor vehicles, aircraft, certain types of HVAC equipment and major appliances. It also put local government on notice as to their responsibilities in land use planning to address noise mitigation. This noise regulation framework comprised a broad data base detailing the extent of noise health effects.
The state of California's Office of Environmental Health Hazard Assessment (OEHHA) has maintained an independent list of substances with product labeling requirements as part of Proposition 65 since 1986.
With the 1990 Clean Air Act, the EPA began a controversial carbon trading system in which tradable rights to emit a specified level of carbon are granted to polluters.
The United States has a maximum fine of US$25,000 for dumping toxic waste.
In Canada the regulation of pollution and its effects are monitored by a number of organizations depending on the nature of the pollution and its location. The three levels of governemnt (Federal - Canada Wide; Provincial; and Municipal) equally share in the responsibilities, and in the monitoring and correction of pollution.
For the Air there is the organization "Environment Canada", and for specific provincial duties, there are the respective branches of the Provincial entities that deal with areas such as potable water, Oceans, and the Natural Resources of the lands and waters.All together quite a hodgepodge of offices
There are laws and regulations written for the Air, Water, and Soil, but these are subject to change at any given time depending on the Government of the Day.
History
Prehistory
Humankind has some effect upon the natural environment since the Paleolithic era during which the ability to generate fire was acquired. In the Iron Age, the use of tooling led to the practice of metal grinding on a small scale and resulted in minor accumulations of discarded material probably easily dispersed without too much impact. Human wastes would have polluted rivers or water sources to some degree. However, these effects could be expected predominantly to be dwarfed by the natural world.
Ancient cultures
The first advanced civilizations of Mesopotamia, Egypt, India, China, Persia, Greece and Rome increased the use of water for their manufacture of goods, increasingly forged metal and created fires of wood and peat for more elaborate purposes (for example, bathing, heating). Still, at this time the scale of higher activity did not disrupt ecosystems or greatly alter air or water quality.
Middle Ages
The European Dark Ages during the early Middle Ages were a great boon for the environment, in that industrial activity fell, and population levels did not grow rapidly. Toward the end of the Middle Ages populations grew and concentrated more within cities, creating pockets of readily evident contamination. In certain places air pollution levels were recognizable as health issues, and water pollution in population centers was a serious medium for disease transmission from untreated human waste.
Since travel and widespread information were less common, there did not exist a more general context than that of local consequences in which to consider pollution. Foul air would have been considered a nuissance and wood, or eventually, coal burning produced
smoke, which in sufficient concentrations could be a health hazard in proximity to living quarters. Septic contamination or poisoning of a clean drinking water source was very easily fatal to those who depended on it, especially if such a resource was rare. Superstitions predominated and the extent of such concerns would probably have been little more than a sense of moderation and an avoidance of obvious extremes.
Official acknowledgement
But gradually increasing populations and the proliferation of basic industrial processes saw the emergence of a civilization that began to have a much greater collective impact on its surroundings. It was to be expected that the beginnings of environmental awareness would occur in the more developed cultures, particularly in the densest urban centers. The first medium warranting official policy measures in the emerging western world would be the most basic: the air we breathe.
The earliest known writings concerned with pollution were Arabic medical treatises written between the 9th and 13th centuries, by physicians such as al-Kindi (Alkindus), Qusta ibn Luqa (Costa ben Luca), Muhammad ibn Zakarīya Rāzi (Rhazes), Ibn Al-Jazzar, al-Tamimi, al-Masihi, Ibn Sina (Avicenna), Ali ibn Ridwan, Ibn Jumay, Isaac Israeli ben Solomon, Abd-el-latif, Ibn al-Quff, and Ibn al-Nafis. Their works covered a number of subjects related to pollution such as air contamination, water contamination, soil contamination, solid waste mishandling, and environmental assessments of certain localities.[16]
King Edward I of England banned the burning of sea-coal by proclamation in London in 1272, after its smoke had become a problem.[17][18] But the fuel was so common in England that this earliest of names for it was acquired because it could be carted away from some shores by the wheelbarrow. Air pollution would continue to be a problem there, especially later during the industrial revolution, and extending into the recent past with the Great Smog of 1952. This same city also recorded one of the earlier extreme cases of water quality problems with the Great Stink on the Thames of 1858, which led to construction of the London sewerage system soon afterward.
It was the industrial revolution that gave birth to environmental pollution as we know it today. The emergence of great factories and consumption of immense quantities of coal and other fossil fuels gave rise to unprecedented air pollution and the large volume of industrial chemical discharges added to the growing load of untreated human waste. Chicago and Cincinnati were the first two American cities to enact laws ensuring cleaner air in 1881. Other cities followed around the country until early in the 20th century, when the short lived Office of Air Pollution was created under the Department of the Interior. Extreme smog events were experienced by the cities of Los Angeles and Donora, Pennsylvania in the late 1940s, serving as another public reminder.[19]
Early Soviet poster, before the modern awareness: "The smoke of chimneys is the breath of Soviet Russia"
Pollution began to draw major public attention in the United States between the mid-1950s and early 1970s, when Congress passed the Noise Control Act, the Clean Air Act, the Clean Water Act and the National Environmental Policy Act.
Bad bouts of local pollution helped increase consciousness. PCB dumping in the Hudson River resulted in a ban by the EPA on consumption of its fish in 1974. Long-term dioxin contamination at Love Canal starting in 1947 became a national news story in 1978 and led to the Superfund legislation of 1980. Legal proceedings in the 1990s helped bring to light Chromium-6 releases in California--the champions of whose victims became famous. The pollution of industrial land gave rise to the name brownfield, a term now common in city planning. DDT was banned in most of the developed world after the publication of Rachel Carson's Silent Spring.
The development of nuclear science introduced radioactive contamination, which can remain lethally radioactive for hundreds of thousands of years. Lake Karachay, named by the Worldwatch Institute as the "most polluted spot" on earth, served as a disposal site for the Soviet Union thoroughout the 1950s and 1960s. Second place may go to the to the area of Chelyabinsk U.S.S.R. (see reference below) as the "Most polluted place on the planet".
Nuclear weapons continued to be tested in the Cold War, sometimes near inhabited areas, especially in the earlier stages of their development. The toll on the worst-affected populations and the growth since then in understanding about the critical threat to human health posed by radioactivity has also been a prohibitive complication associated with nuclear power. Though extreme care is practiced in that industry, the potential for disaster suggested by incidents such as those at Three Mile Island and Chernobyl pose a lingering specter of public mistrust. One legacy of nuclear testing before most forms were banned has been significantly raised levels of background radiation.
International catastrophes such as the wreck of the Amoco Cadiz oil tanker off the coast of Brittany in 1978 and the Bhopal disaster in 1984 have demonstrated the universality of such events and the scale on which efforts to address them needed to engage. The borderless nature of the atmosphere and oceans inevitably resulted in the implication of pollution on a planetary level with the issue of global warming. Most recently the term persistent organic pollutant (POP) has come to describe a group of chemicals such as PBDEs and PFCs among others. Though their effects remain somewhat less well understood owing to a lack of experimental data, they have been detected in various ecological habitats far removed from industrial activity such as the Arctic, demonstrating diffusion and bioaccumulation after only a relatively brief period of widespread use.
Growing evidence of local and global pollution and an increasingly informed public over time have given rise to environmentalism and the environmental movement, which generally seek to limit human impact on the environment.
Philosophical recognition
Throughout history from Ancient Greece to Andalusia, Ancient China, central Europe during the Renaissance until today, philosophers ranging from Aristotle, Al-Farabi, Al-Ghazali, Averroes, Buddha, Confucius, Dante, Hegel, Avicenna, Lao Tse, Maimonedes, Montesquieu, Nussbaum, Plato, Socrates and Sun Tzu wrote about the pollution of the body as well as the mind and soul.
Perspectives
The earliest precursor of pollution generated by life forms would have been a natural function of their existence. The attendant consequences on viability and population levels fell within the sphere of natural selection. These would have included the demise of a population locally or ultimately, species extinction. Processes that were untenable would have resulted in a new balance brought about by changes and adaptations. At the extremes, for any form of life, consideration of pollution is superseded by that of survival.
For mankind, the factor of technology is a distinguishing and critical consideration, both as an enabler and an additional source of byproducts. Short of survival, human concerns include the range from quality of life to health hazards. Since science holds experimental demonstration to be definitive, modern treatment of toxicity or environmental harm involves defining a level at which an effect is observable. Common examples of fields where practical measurement is crucial include automobile emissions control, industrial exposure (eg Occupational Safety and Health Administration (OSHA) PELs), toxicology (eg LD50), and medicine (eg medication and radiation doses).
"The solution to pollution is dilution", is a dictum which summarizes a traditional approach to pollution management whereby sufficiently diluted pollution is not harmful.[20][21] It is well-suited to some other modern, locally-scoped applications such as laboratory safety procedure and hazardous material release emergency management. But it assumes that the dilutant is in virtually unlimited supply for the application or that resulting dilutions are acceptable in all cases.
Such simple treatment for environmental pollution on a wider scale might have had greater merit in earlier centuries when physical survival was often the highest imperative, human population and densities were lower, technologies were simpler and their byproducts more benign. But these are often no longer the case. Furthermore, advances have enabled measurement of concentrations not possible before. The use of statistical methods in evaluating outcomes has given currency to the principle of probable harm in cases where assessment is warranted but resorting to deterministic models is impractical or unfeasible. In addition, consideration of the environment beyond direct impact on human beings has gained prominence.
Yet in the absence of a superseding principle, this older approach predominates practices throughout the world. It is the basis by which to gauge concentrations of effluent for legal release, exceeding which penalties are assessed or restrictions applied. The regressive cases are those where a controlled level of release is too high or, if enforceable, is neglected. Migration from pollution dilution to elimination in many cases is confronted by challenging economical and technological barriers.
Controversies
Industry and concerned citizens have battled for decades over the significance of various forms of pollution. Salient parameters of these disputes are whether:
a given pollutant affects all people or simply a genetically vulnerable set. an effect is only specific to certain species. whether the effect is simple, or whether it causes linked secondary and tertiary
effects, especially on biodiversity an effect will only be apparent in the future and is presently negligible. the threshold for harm is present. the pollutant is of direct harm or is a precursor. employment or economic prosperity will suffer if the pollutant is abated.
Blooms of algae and the resultant eutrophication of lakes and coastal ocean is considered pollution when it is caused by nutrients from industrial, agricultural, or residential runoff in either point source or nonpoint source form (see the article on eutrophication for more information).
Heavy metals such as lead and mercury have a role in geochemical cycles and they occur naturally. These metals may also be mined and, depending on their processing, may be released disruptively in large concentrations into an environment they had previously been absent from. Just as the effect of anthropogenic release of these metals into the environment may be considered 'polluting', similar environmental impacts could also occur in some areas due to either autochthonous or historically 'natural' geochemical activity.
Greenhouse gases and global warming
Historical and projected CO2 emissions by country.Source: Energy Information Administration.
Carbon dioxide, while vital for photosynthesis, is sometimes referred to as pollution, because raised levels of the gas in the atmosphere are affecting the Earth's climate. Disruption of the environment can also highlight the connection between areas of pollution that would normally be classified separately, such as those of water and air. Recent studies have investigated the potential for long-term rising levels of atmospheric carbon dioxide to cause slight but critical increases in the acidity of ocean waters, and the possible effects of this on marine ecosystems.
Air pollution is the modification of the natural characteristics of the atmosphere by a chemical, particulate matter, or biological agent. The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.
Worldwide air pollution is responsible for large numbers of deaths [1] and cases of respiratory disease.[2] While major stationary sources are often identified with air pollution, the greatest source of emissions is actually mobile sources, mainly automobiles.[3] Gases such as carbon dioxide, which contribute to global warming, have recently gained recognition as pollutants by climate scientists, while they also recognize that carbon dioxide is essential for plant life through photosynthesis.
Pollutants
Before flue gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.
There are many substances in the air which may impair the health of plants and animals (including humans), or reduce visibility. These arise both from natural processes and human activity. Substances not naturally found in the air or at greater concentrations or in different locations from usual are referred to as pollutants.
Pollutants can be classified as either primary or secondary. Primary pollutants are substances directly emitted from a process, such as ash from a volcanic eruption or the carbon monoxide gas from a motor vehicle exhaust.
Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone - one of the many secondary pollutants that make up photochemical smog.
Note that some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.
Major primary pollutants produced by human activity include:
Sulfur oxides (SOx) especially sulfur dioxide are emitted from burning of coal and oil.
Nitrogen oxides (NOx) especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities.
Carbon monoxide is colourless, odourless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
Carbon dioxide (CO2), a greenhouse gas emitted from combustion. Volatile organic compounds (VOC), such as hydrocarbon fuel vapors and
solvents. Particulate matter (PM), measured as smoke and dust. PM10 is the fraction of
suspended particles 10 micrometers in diameter and smaller that will enter the nasal cavity. PM2.5 has a maximum particle size of 2.5 µm and will enter the bronchies and lungs.
Toxic metals, such as lead, cadmium and copper. Chlorofluorocarbons (CFCs), harmful to the ozone layer emitted from products
currently banned from use. Ammonia (NH3) emitted from agricultural processes. Odors, such as from garbage, sewage, and industrial processes Radioactive pollutants produced by nuclear explosions and war explosives, and
natural processes such as radon.
Secondary pollutants include:
Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog, such as nitrogen dioxide.
Ground level ozone (O3) formed from NOx and VOCs. Peroxyacetyl nitrate (PAN) similarly formed from NOx and VOCs.
Minor air pollutants include:
A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.
A variety of persistent organic pollutants, which can attach to particulate matter.
Using a controlled burn on a field in South Georgia in preparation for spring planting.
Sources of air pollution refer to the various locations, activities or factors which are responsible for the releasing of pollutants in the atmosphere. These sources can be classified into two major categories which are:
Anthropogenic sources (human activity) mostly related to burning different kinds of fuel
"Stationary Sources" as smoke stacks of power plants, manufacturing facilities, municipal waste incinerators.
"Mobile Sources" as motor vehicles, aircraft etc. Marine vessels, such as container ships or cruise ships, and related port air
pollution. Burning wood, fireplaces, stoves, furnaces and incinerators . Oil refining, and industrial activity in general. Chemicals, dust and controlled burn practices in agriculture and forestry
management, (see Dust Bowl). Fumes from paint, hair spray, varnish, aerosol sprays and other solvents. Waste deposition in landfills, which generate methane. Military, such as nuclear weapons, toxic gases, germ warfare and rocketry.
Dust from natural sources, usually large areas of land with little or no vegetation. Methane, emitted by the digestion of food by animals, for example cattle. Radon gas from radioactive decay within the Earth's crust. Smoke and carbon monoxide from wildfires. Volcanic activity, which produce sulfur, chlorine, and ash particulates.
Air pollutant emission factors
Air pollutant emission factors are representative values that attempt to relate the quantity of a pollutant released to the ambient air with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant (e.g., kilograms of particulate emitted per megagram of coal burned). Such factors facilitate estimation of emissions from various sources of air pollution. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally assumed to be representative of long-term averages.
The United States Environmental Protection Agency has published a compilation of air pollutant emission factors for a multitude of industrial sources.[4] The United Kingdom, Australia, Canada and other countries have published similar compilations, as has the European Environment Agency.[5][6] [7][8] [9]
Indoor air quality (IAQ)
A lack of ventilation indoors concentrates air pollution where people often spend the majority of their time. Radon (Rn) gas, a carcinogen, is exuded from the Earth in certain locations and trapped inside houses. Building materials including carpeting and plywood emit formaldehyde (H2CO) gas. Paint and solvents give off volatile organic compounds (VOCs) as they dry. Lead paint can degenerate into dust and be inhaled. Intentional air pollution is introduced with the use of air fresheners, incense, and other scented items. Controlled wood fires in stoves and fireplaces can add significant amounts of smoke particulates into the air, inside and out. Indoor pollution fatalities may be caused by using pesticides and other chemical sprays indoors without proper ventilation.
Carbon monoxide (CO) poisoning and fatalities are often caused by faulty vents and chimneys, or by the burning of charcoal indoors. Chronic carbon monoxide poisoning can result even from poorly adjusted pilot lights. Traps are built into all domestic plumbing to keep sewer gas, hydrogen sulfide, out of interiors. Clothing emits tetrachloroethylene, or other dry cleaning fluids, for days after dry cleaning.
Though its use has now been banned in many countries, the extensive use of asbestos in industrial and domestic environments in the past has left a potentially very dangerous material in many localities. Asbestosis is a chronic inflammatory medical condition affecting the tissue of the lungs. It occurs after long-term, heavy exposure to asbestos from asbestos-containing materials in structures. Sufferers have severe dyspnea (shortness of breath) and are at an increased risk regarding several different types of lung cancer. As clear explanations are not always stressed in non-technical literature, care should be taken to distinguish between several forms of relevant diseases. According to the World Health Organisation (WHO), these may defined as; asbestosis, lung cancer, and mesothelioma (generally a very rare form of cancer, when more widespread it is almost always associated with prolonged exposure to asbestos).
Biological sources of air pollution are also found indoors, as gases and airborne particulates. Pets produce dander, people produce dust from minute skin flakes and decomposed hair, dust mites in bedding, carpeting and furniture produce enzymes and micrometre-sized fecal droppings, inhabitants emit methane, mold forms in walls and generates mycotoxins and spores, air conditioning systems can incubate Legionnaires' disease and mold, and houseplants, soil and surrounding gardens can produce pollen, dust, and mold. Indoors, the lack of air circulation allows these airborne pollutants to accumulate more than they would otherwise occur in nature.
Health effects
The World Health Organization states that 2.4 million people die each year from causes directly attributable to air pollution.[2] Many of these mortalities are attributable to indoor air pollution.[citation needed] Worldwide more deaths per year are linked to air pollution than to automobile accidents.[citation needed] Published in 2005 suggests that 310,000 Europeans die from air pollution annually.[citation needed] Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies.[citation needed] The US EPA estimates that a proposed set of changes in diesel engine technology (Tier 2) could result in 12,000 fewer premature mortalities, 15,000 fewer heart attacks, 6,000 fewer emergency room visits by children with asthma, and 8,900 fewer respiratory-related hospital admissions each year in the United States.[citation needed]
The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.[10] Leaked industrial vapors from the Union Carbide factory, belonging to Union Carbide, Inc., U.S.A., killed more than 2,000 people outright and injured anywhere from 150,000 to 600,000 others, some 6,000 of whom would later die from their injuries.[citation needed] The United Kingdom suffered its worst air pollution event when the December 4 Great Smog of 1952 formed over London. In six days more than 4,000 died, and 8,000 more died within the following months.[citation needed] An accidental leak of anthrax spores from a biological warfare laboratory in the former USSR in 1979 near Sverdlovsk is believed to have been the cause of hundreds of civilian deaths.[citation needed] The worst single incident of air pollution to occur in the United States of America occurred in Donora, Pennsylvania in late October, 1948, when 20 people died and over 7,000 were injured.[11]
The health effects caused by air pollutants may range from subtle biochemical and physiological changes to difficulty in breathing, wheezing, coughing and aggravation of existing respiratory and cardiac conditions. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and premature death. The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics.[citation needed]
Reduction efforts
There are various air pollution control technologies and urban planning strategies available to reduce air pollution.
Efforts to reduce pollution from mobile sources includes primary regulation (many developing countries have permissive regulations)[citation needed], expanding regulation to new sources (such as cruise and transport ships, farm equipment, and small gas-powered equipment such as lawn trimmers, chainsaws, and snowmobiles), increased fuel efficiency (such as through the use of hybrid vehicles), conversion to cleaner fuels (such as bioethanol, biodiesel, or conversion to electric vehicles).
Control devices
The following items are commonly used as pollution control devices by industry or transportation devices. They can either destroy contaminants or remove them from an exhaust stream before it is emitted into the atmosphere.
Particulate control o Mechanical collectors (dust cyclones, multicyclones)o Electrostatic precipitatorso Baghouseso Particulate scrubbers
In general, there are two types of air quality standards. The first class of standards (such as the U.S. National Ambient Air Quality Standards) set maximum atmospheric concentrations for specific pollutants. Environmental agencies enact regulations which are intended to result in attainment of these target levels. The second class (such as the North American Air Quality Index) take the form of a scale with various thresholds, which is used to communicate to the public the relative risk of outdoor activity. The scale may or may not distinguish between different pollutants.
Canada
In Canada, air quality is typically evaluated against standards set by the Canadian Council of Minister for the Environment (CCME), an inter-governmental body of federal, provincial and territorial Ministers responsible for the environment. The CCME has set Canada Wide Standards(CWS).[12][13] These are:
CWS for PM2.5 = 30 µg/m3 (24 hour averaging time, by year 2010, based on 98th percentile ambient measurement annually, averaged over 3 consecutive years).
CWS for ozone = 65 ppb (8-hour averaging time, by year 2010, achievement is based on the 4th highest measurement annually, averaged over 3 consecutive years.
Note that there is no consequence in Canada to not achieving these standards. In addition, these only apply to jurisdictions with populations greater than 100,000. Further, provinces and territories may set more stringent standards than those set by the CCME.
European Union
National Emission Ceilings (NEC) for certain atmospheric pollutants are regulated by Directive 2001/81/EC (NECD).[14] As part of the preparatory work associated with the revision of the NECD, the European Commission is assisted by the NECPI working group (National Emission Ceilings – Policy Instruments).[15]
United Kingdom
Air quality targets set by the UK's Department for Environment, Food and Rural Affairs (DEFRA) are mostly aimed at local government representatives responsible for the management of air quality in cities, where air quality management is the most urgent. The UK has established an air quality network where levels of the key air pollutants[16] are published by monitoring centers.[17] Air quality in Oxford, Bath and London[18] is particularly poor. One controversial study[19] performed by the Calor Gas company and published in the Guardian newspaper compared walking in Oxford on an average day to smoking over sixty light cigarettes.
More precise comparisons can be collected from the UK Air Quality Archive[20] which allows the user to compare a cities management of pollutants against the national air quality objectives[21] set by DEFRA in 2000.
Localized peak values are often cited, but average values are also important to human health. The UK National Air Quality Information Archive offers almost real-time monitoring of "current maximum" air pollution measurements for many UK towns and cities.[22] This source offers a wide range of constantly updated data, including:
Hourly Mean Ozone (µg/m³) Hourly Mean Nitrogen dioxide (µg/m³) Maximum 15-Minute Mean Sulphur dioxide (µg/m³) 8-Hour Mean Carbon monoxide (mg/m³) 24-Hour Mean PM10 (µg/m³ Grav Equiv)
DEFRA acknowledges that air pollution has a significant effect on health and has produced a simple banding index system[23] is used to create a daily warning system that is issued by the BBC Weather Service to indicate air pollution levels.[24] DEFRA has published guidelines for people suffering from respiratory and heart diseases.[25]
United States
Looking down from the Hollywood Hills, with Griffith Observatory on the hill in the foreground, air pollution is visible in downtown Los Angeles on a late afternoon.
In the 1960s, 70s, and 90s, the United States Congress enacted a series of Clean Air Acts which significantly strengthened regulation of air pollution. Individual U.S. states, some European nations and eventually the European Union followed these initiatives. The Clean Air Act sets numerical limits on the concentrations of a basic group of air pollutants and provide reporting and enforcement mechanisms.
In 1999, the United States EPA replaced the Pollution Standards Index (PSI) with the Air Quality Index (AQI) to incorporate new PM2.5 and Ozone standards.
The effects of these laws have been very positive. In the United States between 1970 and 2006, citizens enjoyed the following reductions in annual pollution emissions:[26]
carbon monoxide emissions fell from 197 million tons to 89 million tons nitrogen oxide emissions fell from 27 million tons to 19 million tons sulfur dioxide emissions fell from 31 million tons to 15 million tons
particulate emissions fell by 80% lead emissions fell by more than 98%
In an October 2006 letter to EPA, the agency's independent scientific advisors warned that the ozone smog standard “needs to be substantially reduced” and that there is “no scientific justification” for retaining the current, weaker standard. The scientists unanimously recommended a smog threshold of 60 to 70 ppb after they conducted an extensive review of the evidence. [27]
The EPA has proposed, in June 2007, a new threshold of 75 ppb. This falls short of the scientific recommendation, but is an improvement over the current standard.
Polluting industries are lobbying to keep the current (weaker) standards in place. Environmentalists and public health advocates are mobilizing to support compliance with the scientific recommendations.[citation needed]
The National Ambient Air Quality Standards are pollution thresholds which trigger mandatory remediation plans by state and local governments, subject to enforcement by the EPA.
An outpouring of dust layered with man-made sulfates, smog, industrial fumes, carbon grit, and nitrates is crossing the Pacific Ocean on prevailing winds from booming Asian economies in plumes so vast they alter the climate. Almost a third of the air over Los Angeles and San Francisco can be traced directly to Asia. With it comes up to three-quarters of the black carbon particulate pollution that reaches the West Coast. [28]
Geography
Most Polluted Cities
Air pollution is usually concentrated in densely populated metropolitan areas, especially in developing countries where environmental regulations are generally relatively lax. However, even populated areas in developed countries attain unhealthy levels of pollution.
Most Polluted World Cities by PM[29]
Particulatematter,
μg/m³ (2004)City
169 Cairo, Egypt150 Delhi, India128 Kolkata, India (Calcutta)125 Tianjin, China123 Chongqing, China109 Kanpur, India109 Lucknow, India104 Jakarta, Indonesia101 Shenyang, China
Counties in the United States that violate National Ambient Air Quality Standards, as of June 2007. Air pollution is a health concern even in developed countries like the U.S.
Carbon dioxide emissions
The source of these data is the Carbon Monitoring for Action (CARMA) database produced by the Center for Global Development.[30]
Total
106 Tons of CO2 per year:
United States: 2,790 China: 2,680 Russia: 661 India: 583 Japan: 400 Germany: 356 Australia: 226 South Africa: 222 United Kingdom: 212 South Korea: 185
Per capita
Tons of CO2 per year per capita:
Australia: 10 United States: 8.2 United Kingdom: 3.2 China: 1.8 India: 0.5
The basic technology for analyzing air pollution is through the use of a variety of mathematical models for predicting the transport of air pollutants in the lower atmosphere. The principal methodologies are:
Point source dispersion, used for industrial sources. Line source dispersion, used for airport and roadway air dispersion modeling Area source dispersion, used for forest fires or duststorms Photochemical models, used to analyze reactive pollutants that form smog
Visualization of a buoyant Gaussian air pollution dispersion plume as used in many atmospheric dispersion models
The point source problem is the best understood, since it involves simpler mathematics and has been studied for a long period of time, dating back to about the year 1900. It uses a Gaussian dispersion model for buoyant pollution plumes to forecast the air pollution isopleths, with consideration given to wind velocity, stack height, emission rate and stability class (a measure of atmospheric turbulence).[31][32] This model has been extensively validated and calibrated with experimental data for all sorts of atmospheric conditions.
The roadway air dispersion model was developed starting in the late 1950s and early 1960s in response to requirements of the National Environmental Policy Act and the U.S. Department of Transportation (then known as the Federal Highway Administration) to understand impacts of proposed new highways upon air quality, especially in urban areas. Several research groups were active in this model development, among which were: the Environmental Research and Technology (ERT) group in Lexington, Massachusetts, the ESL Inc. group in Sunnyvale, California and the California Air Resources Board group in Sacramento, California. The research of the ESL group received a boost with a contract award from the United States Environmental Protection Agency to validate a line source
model using sulfur hexafluoride as a tracer gas. This program was successful in validating the line source model developed by ESL inc. Some of the earliest uses of the model were in court cases involving highway air pollution, the Arlington, Virginia portion of Interstate 66 and the New Jersey Turnpike widening project through East Brunswick, New Jersey.
Area source models were developed in 1971 through 1974 by the ERT and ESL groups, but addressed a smaller fraction of total air pollution emissions, so that their use and need was not as widespread as the line source model, which enjoyed hundreds of different applications as early as the 1970s. Similarly photochemical models were developed primarily in the 1960s and 1970s, but their use was more specialized and for regional needs, such as understanding smog formation in Los Angeles, California.
Environmental impacts
The greenhouse effect is a phenomenon whereby greenhouse gases, create a condition in the upper atmosphere causing a trapping of heat and leading to increased surface and lower tropospheric temperatures. It shares this property with many other gases, the largest overall forcing on Earth coming from water vapour. Other greenhouse gases include methane, hydrofluorocarbons, perfluorocarbons, chlorofluorocarbons, NOx, and ozone. Many greenhouse gases, contain carbon, and some of that from fossil fuels.
This effect has been understood by scientists for about a century, and technological advancements during this period have helped increase the breadth and depth of data relating to the phenomenon. Currently, scientists are studying the role of changes in composition of greenhouse gases from natural and anthropogenic sources for the effect on climate change.
A number of studies have also investigated the potential for long-term rising levels of atmospheric carbon dioxide to cause slight increases in the acidity of ocean waters and the possible effects of this on marine ecosystems. However, carbonic acid is a very weak acid, and is utilized by marine organisms during photosynthesis.
Raw sewage and industrial waste flows into the U.S. from Mexico as the New River passes from Mexicali, Baja California to Calexico, California
Water pollution is a large set of adverse effects upon water bodies such as lakes, rivers, oceans, and groundwater caused by human activities.
Although natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water, water is only called polluted when it is not able to be used for what one wants it to be used for. Water pollution has many causes and characteristics. Increases in nutrient loading may lead to eutrophication. Organic wastes such as sewage impose high oxygen demands on the receiving water leading to oxygen depletion with potentially severe impacts on the whole eco-system. Industries discharge a variety of pollutants in their wastewater including heavy metals, resin pellets, organic toxins, oils, nutrients, and solids. Discharges can also have thermal effects, especially those from power stations, and these too reduce the available oxygen. Silt-bearing runoff from many activities including construction sites, deforestation and agriculture can inhibit the penetration of sunlight through the water column, restricting photosynthesis and causing blanketing of the lake or river bed, in turn damaging ecological systems.
Pollutants in water include a wide spectrum of chemicals, pathogens, and physical chemistry or sensory changes. Many of the chemical substances are toxic. Pathogens can produce waterborne diseases in either human or animal hosts. Alteration of water's physical chemistry include acidity, electrical conductivity, temperature, and eutrophication. Eutrophication is the fertilisation of surface water by nutrients that were previously scarce. Even many of the municipal water supplies in developed countries can present health risks. Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases,[1][2] and that it accounts for the deaths of more than 14,000 people daily.[2]
Contaminants
Contaminants may include organic and inorganic substances.
Some organic water pollutants are:
Insecticides and herbicides, a huge range of organohalide and other chemicals Bacteria, often is from sewage or livestock operations Food processing waste, including pathogens Tree and brush debris from logging operations VOCs (volatile organic compounds), such as industrial solvents, from improper
storage DNAPLs (dense non-aqueous phase liquids), such as chlorinated solvents, which
may fall at the bottom of reservoirs, since they don't mix well with water and are more dense
Petroleum Hydrocarbons including fuels (gasoline, diesel, jet fuels, and fuel oils) and lubricants (motor oil) from oil field operations, refineries, pipelines, retail service station's underground storage tanks, and transfer operations. Note: VOCs include gasoline-range hydrocarbons.
Detergents Various chemical compounds found in personal hygiene and cosmetic products
Some inorganic water pollutants include:
Heavy metals including acid mine drainage Acidity caused by industrial discharges (especially sulphur dioxide from power
plants) Pre-production industrial raw resin pellets, an industrial pollutant Chemical waste as industrial by products Fertilizers, in runoff from agriculture including nitrates and phosphates Silt in surface runoff from construction sites, logging, slash and burn practices or
Transport and chemical reactions of water pollutants
Most water pollutants are eventually carried by the rivers into the oceans. In some areas of the world the influence can be traced hundred miles from the mouth by studies using hydrology transport models. Advanced computer models such as SWMM or the DSSAM Model have been used in many locations worldwide to examine the fate of pollutants in aquatic systems. Indicator filter feeding species such as copepods have also been used to study pollutant fates in the New York Bight, for example. The highest toxin loads are not directly at the mouth of the Hudson River, but 100 kilometers south, since several days are required for incorporation into planktonic tissue. The Hudson discharge flows south along the coast due to coriolis force. Further south then are areas of oxygen depletion, caused by chemicals using up oxygen and by algae blooms, caused by excess nutrients from algal cell death and decomposition. Fish and shellfish kills have been reported, because toxins climb the foodchain after small fish consume copepods, then large fish eat smaller fish, etc. Each successive step up the food chain causes a stepwise concentration of pollutants such as heavy metals (e.g. mercury) and persistent organic pollutants such as DDT. This is known as biomagnification which is occasionally used interchangeably with bioaccumulation.
The big gyres in the oceans trap floating plastic debris. The North Pacific Gyre for example has collected the so-called Great Pacific Garbage Patch that is now estimated at two times the size of Texas. Many of these long-lasting pieces wind up in the stomachs of marine birds and animals. This results in obstruction of digestive pathways which leads to reduced appetite or even starvation.
Many chemicals undergo reactive decay or chemically change especially over long periods of time in groundwater reservoirs. A noteworthy class of such chemicals are the chlorinated hydrocarbons such as trichloroethylene (used in industrial metal degreasing and electronics manufacturing) and tetrachloroethylene used in the dry cleaning industry (note latest advances in liquid carbon dioxide in dry cleaning that avoids all use of chemicals). Both of these chemicals, which are carcinogens themselves, undergo partial decomposition reactions, leading to new hazardous chemicals (including dichloroethylene and vinyl chloride).
Groundwater pollution is much more difficult to abate than surface pollution because groundwater can move great distances through unseen aquifers. Non-porous aquifers such as clays partially purify water of bacteria by simple filtration (adsorption and absorption), dilution, and, in some cases, chemical reactions and biological activity: however, in some cases, the pollutants merely transform to soil contaminants. Groundwater that moves through cracks and caverns is not filtered and can be transported as easily as surface water. In fact, this can be aggravated by the human tendency to use natural sinkholes as dumps in areas of Karst topography.
There are a variety of secondary effects stemming not from the original pollutant, but a derivative condition. Some of these secondary impacts are:
Silt bearing surface runoff from can inhibit the penetration of sunlight through the water column, hampering photosynthesis in aquatic plants.
Thermal pollution can induce fish kills and invasion by new thermophilic species. This can cause further problems to existing wildlife.
Sampling & Monitoring
Sampling water can take several forms depending on the accuracy needed and the characteristics of the contaminant. Many contamination events are temporal and most commonly in association with rain events. For this reason 'grab' samples can be used as indicators, but are often inadequate for fully accessing contaminant concerns in a water body. Scientists gathering this type of data often employ auto-sampler devices that pump increments of water at either time or discharge intervals.
Regulatory framework
In the UK there are common law rights (civil rights) to protect the passage of water across land unfettered in either quality of quantity. Criminal laws dating back to the 16th century exercised some control over water pollution but it was not until the River (Prevention of pollution )Acts 1951 - 1961 were enacted that any systematic control over water pollution was established. These laws were strengthened and extended in the Control of Pollution Act 1984 which has since been updated and modified by a series of further acts. It is a criminal offense to either pollute a lake, river, groundwater or the sea or to discharge any liquid into such water bodies without proper authority. In England and Wales such permission can only be issued by the Environment Agency and in Scotland by SEPA.
In the USA, concern over water pollution resulted in the enactment of state anti-pollution laws in the latter half of the 19th century, and federal legislation enacted in 1899. The Refuse Act of the federal Rivers and Harbors Act of 1899 prohibits the disposal of any refuse matter from into either the nation's navigable rivers, lakes, streams, and other navigable bodies of water, or any tributary to such waters, unless one has first obtained a permit. The Water Pollution Control Act, passed in 1948, gave authority to the Surgeon General to reduce water pollution.Growing public awareness and concern for controlling water pollution led to enactment of the Federal Water Pollution Control Act Amendments of 1972. As amended in 1977, this law became commonly known as the Clean Water Act. The Act established the basic mechanisms for regulating contaminant discharge. It established the authority for the United States Environmental Protection Agency to implement wastewater standards for industry. The Clean Water Act also continued requirements to set water quality standards for all contaminants in surface waters. Further amplification of the Act continued including the enactment of the Great Lakes Legacy Act of 2002.
Land pollution is the degradation of earth's land surfaces often caused by human activities and its misuse. Haphazard disposal of urban and industrial wastes, exploitation of minerals, and improper use of soil by inadequate agricultural practices are a few of the contributing factors.[1] Also, increasing urbanization, industrialization and other demands on the environment and its resources is of great consequence to many countries.
The Industrial Revolution set in motion a series of events which impinged on the countryside destroying many natural habitats, and introduced pollution causing disease in both human and animal alike.
Increased mechanization
In some areas more metal ores had to be extracted out of the ground, melted and cast using coal out of the ground and cooled using water, which raised the temperature of water in rivers. (This reduces the oxygen carrying capacity of the water and affects all the living things there.) The excavation of metal ores, sand and limestone led to large scale quarrying and defacing of the countryside. To a large extent this has stopped or is more closely controlled, and attempts have been made to use the holes profitably i.e. sand pits have been turned into boating lochs and quarries have been used as landfill waste sites. Central Scotland bears the scars of years of coal mining, with pit bings and slag heaps visible from the motorways.
Increased urbanization
As the demand for labor grew, the areas round the factories and mines were given over to housing. This took up former agricultural land, caused sewage and waste problems, increased the demands for food and put pressure on farmers to produce more food.
The demand for more housing meant the need to use more raw materials to make bricks, slates for roofing and timber for joists, etc. Once again this led to quarrying and to the destruction of forests. The houses also needed running water and a supply of energy. Initially this water would have been supplied directly from a stream but as demand increased the need for reservoirs increased. This again led to the loss of land as valleys were flooded to meet the demands. The main fuels used would have been coal and wood but as time progressed, hydro electric, coal, oil and nuclear power stations were built which again became features or eyesores on the landscape. Associated with this was the radiating network of pylons forming the National Grid, as well as, the sub stations and transformers. Until the late 1970s little attempt was made to hide these metal structures
but now more care is taken in their siting and underground cables are often used - although these are not popular with repair crews who have to find faults and service them, often in very remote areas.
This increase in the concentration of population into cities, along with the internal combustion engine, led to the increased number of roads and all the infra structure that goes with them. Roads cause visual, noise, light, air and water pollution, as well as using up land. The visual and noise areas are obvious, however light pollution is becoming more widely recognised as a problem. From space large cities can be picked out at night by the glow of their street lighting, so city dwellers seldom experience total darkness. On a smaller scale lights along roads can cause people living there to have interrupted sleep patterns due to the lack of darkness.The contribution of traffic to air pollution is dealt with in another article, but, suffice to say that sulfur dioxide, nitrogen oxides and carbon monoxide are the main culprits. Water pollution is caused by the run off from roads of oil, salt and rubber residue, which enter the water courses and may make conditions unsuitable for certain organisms to live.
Land Pollution
Increased agricultural land and field size
As the demand for food has grown so high, there is an increase in field size and mechanization. The increase in field size is to make it economically viable for the farmer but results in loss of habitat and shelter for wildlife as hedgerows and copses disappear. When crops are harvested the naked soil is left open to wind blow after the heavy machinery has crossed and compacted it. Another consequence of more intensive agriculture is the move to monoculture. This is unnatural, it depletes the soil of nutrients, allows diseases and pests to spread and, in short, brings into play the use of chemical substances foreign to the environment
Pesticides
Pesticides are any chemical used to remove pests whether they are plants or animals. They are used to kill wire worms and slugs that attack cereal crops and to kill ergot - Claviceps purpurea - a fungus that attacks crops and may get into human food.
Herbicides
Herbicides are used to kill weeds, especially on pavements and railways. They are similar to auxins and most are biodegradable by soil bacteria. However one group derived from trinitrophenol (2:4 D and 2:4:5 T) have the impurity dioxin which is very toxic and causes fatality even in low concentrations. It also causes spontaneous abortions, haemorraging and cancer. Agent Orange (50% 2:4:5 T) was used as a defoliant in Vietnam. Eleven million gallons were used and children born since then to American soldiers who served in this conflict, have shown increased physical and mental
disabilities compared to the rest of the population. It affects the head of the sperm and the chromosomes inside it.
Another herbicide, much loved by murder story writers, is Paraquat. It is highly toxic but it rapidly degrades in soil due to the action of bacteria and does not kill soil fauna.
Fungicides
Fungicides are the group used to stop the growth of smuts and rusts on cereals, and mildews and molds like Mucor on plants. The problem is that they may contain copper and mercury. Copper is very toxic at 1ppm to water plants and fish and can enter the skin if being sprayed to reduce mildew and accumulate in the central nervous system. Organomercury compounds have been used to get rid of sedges which are insidious and difficult to remove. However it also can accumulate in birds’ central nervous system and kill them.
Insecticides
Insecticides are used to rid farmers of pests which damage crops. The insects damage not only standing crops but also stored ones and in the tropics it is reckoned that one third of the total production is lost during food storage. As with fungicides, the first used in the nineteenth century were inorganic e.g. Paris Green and other compounds of arsenic. Nicotine has also been used since the late eigtheenth century. There are now two main groups of synthetic ones -
Organochlorines
Organochlorines include DDT, Aldrin, Dieldrin and BHC. They are cheap to produce, potent and persistent. DDT was used on a massive scale from the 1930s, with a peak of 72,000 tonnes used 1970. Then usage fell as the environmental problems were realized. It was found worldwide in fish and birds and was even discovered in the snow in the Antarctic. It is only slightly soluble in water but is very soluble in the bloodstream. It affects the nervous and enzyme systems and causes the eggshells of birds to lack calcium and be so fragile that they break easily. It is thought to be responsible for the decline of the numbers of birds of prey like ospreys and peregrine falcons in the 1950s - they are now recovering.
As well as increased concentration via the food chain, it is known to enter via permeable membranes, so fish get it through their gills. As it has low solubility it tends to stay at the surface, so organisms that live there are most affected. DDT found in fish that formed part of the human food chain caused concern but the levels found in the liver, kidney and brain tissues was less than 1ppm and in fat was 10 ppm which was below the level likely to cause harm. However DDT was banned in Britain and America to stop the further building up of it in the food chain. However, the USA exploited this ban and sold DDT to developing countries who could not afford the expensive replacement chemicals and who did not have such stringent regulations governing the use of pesticides.
Some insects have developed a resistance to insecticides - e.g. the Anopheles mosquito which carries malaria.
Organophosphates
Organophosphates, e.g. parathion, methyl parathion and about 40 other insecticides are available nationally. Parathion is highly toxic, methyl-parathion is less so and Malathion is generally considered safe as it has low toxicity and is rapidly broken down in the mammalian liver. This group works by preventing normal nerve transmission as cholinesterase is prevented from breaking down the transmitter substance acetylcholine, resulting in uncontrolled muscle movements.
Entry of a variety of pesticides into our water supplies causes concern to environmental groups, as in many cases the long term effects of these specific chemicals is not known.
Limits came into force in July 1985 and were so frequently broken that in 1987 formal proceedings were taken against the British government. Britain is still the only European state to use Aldrin and organochlorines, although it was supposed to stop in 1993. East Anglia has the worst record for pesticide contamination of drinking water. Of the 350 pesticides used in Britain, only 50 can be analyzed - this is a worrying thought for many people.[attribution needed]
Increased waste disposal
In Scotland in 1993, 14 million tons of waste were produced. 100,000 tons were special waste and 260,000 tons were controlled waste from other parts of Britain and abroad. 45% of the special waste were in liquid form and 18% were asbestos - radioactive waste was not included. Of the controlled waste, 48% comes from the demolition of buildings, 22% from industry, 17% from households and 13% from business - only 3% are recycled. 90% of controlled waste are buried in landfill sites and produces 2 million tons of methane gas. 1.5% is burned in incinerators and 1.5% are exported to be disposed of or recycled. There are 748 disposal sites in Scotland.
Landfill produces leachate, which has to be recycled to keep favorable conditions for microbial activity, and methane gas and carbon dioxide.There are very little contaminated vacant or derelict land in the north east of Scotland as there are little traditional heavy industry or coal/mineral extraction. However some soil are contaminated by aromatic hydrocarbons (500 cubic meters).
The Urban Waste Water Treatment Directive allows sewage sludge to be sprayed onto land and the volume is expected to double to 185,000 tons of dry solids in 2005. This has good agricultural properties due to the high nitrogen and phosphate content. In 1990/1991, 13% wet weight was sprayed onto 0.13% of the land , however this is expected to rise 15 folds by 2005. There is a need to control this so that pathogenic microorganisms do not get into water courses and to ensure that there are no accumulation of heavy metals in the top soil.
At the end of twentieth century people had even more leisure time and available wealth. This means that people can traveled around the countryside more often increasing the number of cars. This is related back to the roads issue but has also led to the increased litter problem in the countryside. This is usually packaging, cans, bottles, etc. from picnics but increasingly people are dumping household rubbish in the countryside instead of taking it to the local tip. Aesthetically litter is unpleasant but poses threats to the wildlife through razor sharp glass that can be trodden on, plastic bags that can be eaten, etc. More and more litter is becoming a problem especially in the more remote areas which are now more accessible to the general public. Until the public take responsibility to stop littering, then legislation will have little effect and information and education will be the fore runners in the fight against the litter bugs.
Increased military presence
As nations grow so do their armed forces. Over the century,[when?] the army, the navy and latterly the air force has grown in Britain and so has their ownership of land. Apart from the noise and aviation fuel pollution of the air bases, the destruction of land on firing ranges and the change in coastlines to form naval bases, a more sinister trend is the increase in research stations with their "hidden agendas and experiments". This was illustrated by a 1942 experiment on Gruinard Island off the west coast of Scotland.
Anthrax is caused by the bacterium Bacillus anthracis. It was discovered in the 1870s by the German scientist Robert Koch. It mainly affects herbivores, causing them to stagger, convulse and die in a few days. It can also affect man if the spores get onto the skin or lungs. It will form a pus filled blister and was initially treated by a vaccine prepared by Louis Pasteur in 1881. When an animal has died of the disease, the only safe way to dispose of it is to burn it or to bury it very deep in the earth.
However in World War II, knowing all the above problems, the British Government decided to use Anthrax as a biological weapon. In 1942 they dropped Anthrax bombs on Gruinard Island. Their idea - and indeed they produced these - was to drop 5 million Anthrax inoculated linseed cakes into fields of German cattle. The cattle cakes were destroyed at the end of the war unused. However, the Anthrax spores on Gruinard persisted for 40 years until in 1986 the whole island was decontaminated by formaldehyde, and in 1990 returned to its original owners.
This was an example of short sightedness that cost the island of Gruinard 50 years of its "natural life" and which could have spread out of control had it been used on mainland Europe.
This article is about light pollution in the visible spectrum. For information on pollution in the radio spectrum, see radio spectrum pollution..
This time exposure photo of New York City at night shows sky glow, one form of light pollution.
Light pollution, also known as photopollution or luminous pollution, is excess or obtrusive light created by humans. Among other effects, it disrupts ecosystems, can cause adverse health effects, obscures the stars for city dwellers, and interferes with astronomical observatories. Light pollution can be construed to fall into two main branches: annoying light that intrudes on an otherwise natural or low light setting and excessive light, generally indoors, that leads to worker discomfort and adverse health effects. Since the early 1980s, a global dark-sky movement has emerged, with concerned people campaigning to reduce the amount of light pollution.
Light pollution is a side effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Japan, but even relatively small amounts of light can be noticed and create problems. Like other forms of pollution, such as air, water and noise pollution, light pollution causes damage to the environment.
With recent advances in private spaceflight, the prospect of space-based orbiting billboards appearing in the near future has provoked concern that such objects may become another form of light pollution. With this in mind, the United States Federal Aviation Administration sought permission, in May 2005, to enforce a law prohibiting "obtrusive" advertising in earth orbit[1][2]. Similar intentions are yet to be expressed by authorities in most other countries.
Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. The case against light pollution is strengthened by a range of studies on health effects, suggesting that excess light may induce loss in visual acuity, hypertension, headaches and increased incidence of carcinoma. Several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members information about light pollution, the problems it causes, and how to reduce its impact[3].
Since not everyone is irritated by the same lighting sources, it is common for one person's light "pollution" to be light that is desirable for another. One example of this is found in advertising, when an advertiser wishes for particular lights to be bright and visible, even though others find them annoying. Other types of light pollution are more certain. For instance, light that accidentally crosses a property boundary and annoys a neighbor is generally wasted and pollutive light.
Disputes are still common when deciding appropriate action, and differences in opinion over what light is considered reasonable, and who should be responsible, mean that negotiation must sometimes take place between parties. Where objective measurement is desired, light levels can be quantified by field measurement or mathematical modeling, with results typically displayed as an isophote map or light contour map. Authorities have also taken a variety of measures for dealing with light pollution, depending on the interests, beliefs and understandings of the society involved. Measures range from doing nothing at all, to implementing strict laws and regulations about how lights may be installed and used.
Example of a light pollution source using a broad spectrum metal halide lamp pointing upward.[Location]: Uniqema Gouda the Netherlands
Light pollution is a broad term that refers to multiple problems, all of which are caused by inefficient, unappealing, or (arguably) unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, clutter, and sky glow. A single offending light source often falls into more than one of these categories.
Light trespass
Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence. A common light trespass problem occurs when a strong light enters the window of one's home from outside, causing problems such as sleep deprivation or the blocking of an evening view.
Light is particularly problematic for amateur astronomers, whose ability to observe the night sky from their property is likely to be inhibited by any stray light from nearby. Most major optical astronomical observatories are surrounded by zones of strictly-enforced restrictions on light emissions.
A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. To assist them, the International Dark-Sky Association has developed a set of model lighting ordinances[4]]. U.S. federal agencies may also enforce standards and process complaints within their areas of jursidiction. For instance, in the case of light tresspass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the FCC maintains a database of Antenna Structure Registration information which citizens may use to identify offending structures and provides a mechanism for processing consumer inquiries and complaints.
Office building illuminated by high pressure sodium (HPS) lamps shining upward, of which much light goes into the sky and neighboring apartment blocks and causes light pollution. [Location]: Nijmegen, the Netherlands
Composite satellite image of the Earth at night.
Over-illumination is the excessive use of light. Specifically within the United States, over-illumination is responsible for approximately two million barrels of oil per day in energy wasted. This is based upon U.S. consumption of equivalent of 50 million barrels per day of petroleum.[5] It is further noted in the same U.S. Department of Energy source that over 30 percent of all energy is consumed by commercial, industrial and residential sectors. Energy audits of existing buildings demonstrate that the lighting component of residential, commercial and industrial uses consumes about 20 to 40 percent of those land uses, variable with region and land use. (Residential use lighting consumes only 10 to 30 percent of the energy bill while commercial buildings major use is lighting.[6]) Thus lighting energy accounts for about four or five million barrels of oil (equivalent) per day. Again energy audit data demonstrates that about 30 to 60 percent of energy consumed in lighting is unneeded or gratuitous.[7]
An alternative calculation starts with the fact that commercial building lighting consumes in excess of 81.68 terawatts (1999 data) of electricity[8], according to the U.S. DOE. Thus commercial lighting alone consumes about four to five million barrels per day (equivalent) of petroleum, in line with the alternate rationale above to estimate U.S. lighting energy consumption.
Not using timers, occupancy sensors or other controls to extinguish lighting when not needed
Improper design, especially of workplace spaces, by specifying higher levels of light than needed for a given task
Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed
Improper selection of hardware to utilize more energy than needed to accomplish the lighting task
Incomplete training of building managers and occupants to use lighting systems efficiently
Inadequate lighting maintenance resulting in increased stray light and energy costs
Most of these issues can be readily corrected with available, inexpensive technology; however, there is considerable inertia in the field of lighting design and with landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination.
Glare
Glare is often the result of excessive contrast between bright and dark areas in the field of view. For example, glare can be associated with directly viewing the filament of an unshielded or badly shielded light. Light shining into the eyes of pedestrians and drivers can obscure night vision for up to an hour after exposure. Caused by high contrast between light and dark areas, glare can also make it difficult for the human eye to adjust to the differences in brightness. Glare is particularly an issue in road safety, as bright and/or badly shielded lights around roads may partially blind drivers or pedestrians unexpectedly, and contribute to accidents.
Glare can also result in reduced contrast, due to light scattering in the eye by excessive brightness, or to reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare.
Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies[9]. According to this classification:
Blinding Glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies.
Disability Glare describes effects such as being blinded by an oncoming cars lights, or light scattering in fog or in the eye reduces contrast, as well as
reflections from print and other dark areas that render them bright, with significant reduction in sight capabilities.
Discomfort Glare does not typically cause a dangerous situation in itself, and is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods.
Clutter
Clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertising surrounds the roadways. Depending on the motives of the person or organization who installed the lights, their placement and design may even be intended to distract drivers, and can contribute to accidents. Clutter may also present a hazard in the aviation environment if aviation safety lighting must compete for pilot attention with non-relevant lighting[10]. For instance runway lighting may be confused with an array of suburban commercial lighting and aircraft collision avoidance lights may be confused with ground lights.
Sky glow
Mexico City at night, with a brightly illuminated sky.Main article: Sky glow
Sky glow refers to the "glow" effect that can be seen over populated areas. It is the combination of all light reflected from what it has illuminated escaping up into the sky and from all of the badly directed light in that area that also escapes into the sky, being scattered (redirected) by the atmosphere back toward the ground. This scattering is very strongly related to the wavelength of the light when the air is very clear (with very little aerosols). Rayleigh scattering dominates in such clear air, making the sky appear blue in the daytime. When there is significant aerosol (typical of most modern polluted conditions), the scattered light has less dependence on wavelength, making a whiter daytime sky. Because of this Rayleigh effect, and because of the eye's increased sensitivity to white or blue-rich light sources when adapted to very low light levels (see Purkinje effect), white or blue-rich light contributes significantly more to sky-glow than an equal amount of yellow light. Sky glow is of particular irritation to astronomers,
because it reduces contrast in the night sky to the extent where it may even become impossible to see any but the brightest stars.
The Bortle Dark-Sky Scale, originally published in Sky & Telescope magazine,[11] is sometimes used to quantify sky glow and general sky clarity. The Bortle Scale rates the darkness of the sky and the visibility of night sky phenomena such as the gegenschein and the zodiacal band, easily masked by sky glow, on a scale of one to nine, providing a detailed description of each step on the scale.
Measurement of light pollution and global effects
False colors show various intensities of radiation — both direct and indirect — from artificial light sources that reach space (Image credit: P. Cinzano)
Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light. This is caused by two main sources: airglow and scattered light.
At high altitudes, primarily above the mesosphere, UV radiation from the sun is so intense that ionization occurs. When these ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the earth's shadow.
Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way, but also sunlight that is reflected and backscattered from interplanetary dust particles (the so-called Zodiacal light).
The amount of airglow and zodiacal light is quite variable but given optimal conditions the darkest possible sky has a brightness of about 22 magnitude/square arcsecond. If a full moon is present, the sky brightness increases to 18 magnitude/sq. arcsecond, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. arcsecond is not uncommon, or as much as 100 times brighter than is natural.
To precisely measure how bright the sky gets, night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model[12] of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world[13].
Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to 100 km away from the center. Global effects of light pollution are also made obvious. The entire area consisting of southern England, Netherlands, Belgium, west Germany, and northern France have a sky brightness of at least 2 to 4 times above normal (see above right). The only place in continental Europe where the sky can attain its natural darkness is in northern Scandinavia.
In North America the situation is comparable. From the east coast to west Texas up to the Canadian border there is very significant global light pollution.
Consequences of light pollution
Energy waste
Lighting is responsible for one fourth of all energy consumed worldwide[citation needed], and case studies have shown that several forms of over-illumination constitute energy wastage including non-beneficial upward direction of night-time lighting.
Effects on human health and psychology
Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks[14] use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety[15][16][17][18].
Common levels of fluorescent lighting in offices are sufficient to elevate blood pressure by about eight points. There is some evidence that lengthy daily exposure to moderately high lighting leads to diminished sexual performance.[citation needed] Specifically within the USA, there is evidence that levels of light in most office environments lead to increased stress as well as increased worker errors.[19][20] However, such high interior lighting levels are not typical outside North America.
Several published studies also suggest a link between exposure to light at night and risk of breast cancer, due to suppression of the normal nocturnal production of melatonin. [21]
Life exists with natural patterns of light and dark, so disruption of those patterns influences many aspects of animal behavior.[23] Light pollution can confuse animal navigation, alter competitive interactions, change predator-prey relations, and influence animal physiology.
Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, helping cause algal blooms that can kill off the lakes' plants and lower water quality. [24] Light pollution may also affect ecosystems in other ways. For example, Lepidopterists and entomologists have documented that night-time light may interfere with the ability of moths and other nocturnal insects to navigate.[25] Night blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology.
Migrating birds can be disoriented by lights on tall structures. Estimates by the U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from 4-5 million per year to an order of magnitude higher.[26] The Fatal Light Awareness Program (FLAP) works with building owners in Toronto, Canada and other cities to reduce mortality of birds by turning out lights during migration periods.
Other well-known casualties of light pollution are sea turtle hatchlings emerging from nests on beaches. It is a common misconception that hatchling sea turtles are attracted to the moon. They are not; rather, they find the ocean by moving away from the dark silhouette of dunes and their vegetation, a behavior with which artificial lights interfere.[27] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea.
Nocturnal frogs and salamanders are also affected by light pollution. Since they are nocturnal, they wake up when there is no light. Light pollution may cause salamanders to emerge from concealment later, giving them less time to mate and reproduce.
A book that collects together research on the subject was recently released.[28]
It is generally agreed that many people require light to feel safe at night, but campaigners for the reduction of light pollution often claim that badly or inappropriately installed lighting can lead to a reduction in safety if measured objectively, and that at the very least, it is wrong to assume that simply increasing light at night will lead to improved safety.
The International Dark-Sky Association claims there are no good scientific studies that convincingly show a relationship between lighting and crime. Furthermore, the association claims that badly installed artificial lights can create a deeper contrast of shadows in which criminals might hide [29]. The New England Light Pollution Advisory Group claims that some light emitted by some fixtures can be a significant hazard to motorists, pedestrians, and bicyclists due to their scattering of light and glare[30].
The specific effects of outdoor lighting on safety are still a topic of debate, and formal research in the area is not well established.
Effect on astronomy
Skyglow reduces the contrast between stars and galaxies in the sky and the sky itself, making it more difficult to detect fainter objects. This is one factor that has caused newer telescopes to be built in increasingly remote areas. Some astronomers use narrow-band "nebula filters" which only allow specific wavelengths of light commonly seen in nebulae, or broad-band "light pollution filters" which are designed to reduce (but not eliminate) the effects of light pollution by filtering out spectral lines commonly emitted by sodium- and mercury-vapor lamps, thus enhancing contrast and improving the view of dim objects such as galaxies and nebulae.
Light trespass can impact observations when stray light enters the tube of the telescope from off-axis, and is reflected from surfaces other than the telescope's mirrors (if any) so that it eventually reaches the eyepiece, causing a glow across the field of view since it has not been focused. The usual measures to reduce this glare, if reducing the light directly (e.g. by changing one's location or having the light turned off) is not an option, include flocking the telescope tube and accessories to reduce reflection, and putting a light shield (also known as a dew shield) on the telescope to reduce light entering from angles other than those near the target.
Reducing light pollution implies many things, such as reducing sky glow, reducing glare, reducing light trespass, and reducing clutter. The method for best reducing light pollution, therefore, depends on exactly what the problem is in any given instance. Possible solutions include:
Utilizing light sources of minimum intensity necessary to accomplish the light's purpose.
Turning lights off using a timer or occupancy sensor or manually when not needed.
Improving lighting fixtures, so that they direct their light more accurately towards where it is needed, and with less side effects.
Adjusting the type of lights used, so that the light waves emitted are those that are less likely to cause severe light pollution problems.
Evaluating existing lighting plans, and re-designing some or all of the plans depending on whether existing light is actually needed.
Improving lighting fixtures
A flat-lens cobra luminaire, which is a full-cutoff fixture, may be effective in reducing light pollution. It ensures that light is only directed below the horizontal, which means less light is wasted through directing it outwards and upwards.
This drop-lens cobra luminaire allows light to escape sideways and upwards, where it may cause problems.
The use of full cutoff lighting fixtures, as much as possible, is advocated by most campaigners for the reduction of light pollution. It is also commonly recommended that lights be spaced appropriately for maximum efficiency, and that lamps within the fixtures not be overpowered.
A full cutoff fixture, when correctly installed, reduces the chance for light to escape above the plane of the horizontal. Light released above the horizontal may sometimes be lighting an intended target, but often serves no purpose. When it enters into the atmosphere, light contributes to sky glow. Some governments and organizations are now considering, or have already implemented, full cutoff fixtures in street lamps and stadium lighting.
The use of full cutoff fixtures may help to reduce sky glow by preventing light from escaping unnecessarily. Full cutoff typically reduces the visibility of the lamp and reflector within a luminarie, so the effects of glare may also be reduced. Campaigners also commonly argue that full cutoff fixtures are more efficient than other fixtures, since light that would otherwise have escaped into the atmosphere may instead be directed towards the ground. However full cutoff fixtures may also trap more light in the fixture than other types of luminaires, corresponding to lower luminaire efficiency.
The use of full cutoff fixtures may allow for lower wattage lamps to be used in the fixtures, producing the same or sometimes a better effect, due to being more carefully controlled. In every lighting system, some sky glow also results from light reflected from the ground. This reflection can be reduced, however, by being careful to use only the lowest wattage necessary for the lamp, and setting spacing between lights appropriately.[31].
A common criticism of full cutoff lighting fixtures is that they are sometimes not as aesthetically pleasing to look at. This is most likely because historically there has not been a large market specifically for full cutoff fixtures, and because people typically like to see the source of illumination. Due to the specificity with their direction of light, full cutoff fixtures sometimes also require expertise to install for maximum effect.
Another criticism of full cutoff lighting, particularly in the USA, is that luminaires with full cutoff distributions typically have to be closer together than other light distributions used to meet the same roadway lighting requirements specified by the Illuminating Engineering Society of North America, in terms of light level, uniformity and glare [32] [33]
[34] [35]. The issue is very complex: the spread of light from any lamp depends largely on the design of the optics inside, and full-cut-off types are not *necessarily* closer together than the old stock that they replace - on the M5 motorway in SW England, for example, new FCOs were installed further apart than the old, deep-bowl types they replaced, on columns of similar height. Due to the complexity of roadway lighting design, sometimes existing lighting was not optimized at its design, so there is significant room for improvement. However, according to published research (see previous ref.s), when lighting designs are optimized, using full-cut-off luminaires does typically correspond to increased initial costs, maintenance costs, operating costs, energy use, energy pollution,
and possibly light pollution, compared to using other distributions to meet the same roadway lighting requirements.[citation needed]
Adjusting types of light sources
Several different types of light sources exist, each having different properties that determine their appropriateness for certain tasks, particularly efficiency and spectral power distribution. It is often the case that inappropriate light sources have been selected for a task, either due to ignorance or because more sophisticated light sources were unavailable at the time of installation. Therefore, badly chosen light sources often contribute to light pollution unnecessarily. By re-assessing and changing the light sources used, it is often possible to reduce pollutive effects.
Some types of light sources, in order of energy efficiency, are:
Type of light source Color Efficiency(lumens per watt)
Many astronomers prefer their neighboring societies to use low pressure sodium lights as much as possible, because the single wavelength involved is comparably easy to filter. The low cost of operating sodium lights is another feature. In 1980, for example, San Jose, California, replaced all street lamps with low pressure sodium lamps, whose light is easier for nearby Lick Observatory to filter out. Similar programs are now in place in Arizona and Hawaii.
Disadvantages of low pressure sodium lighting are that fixtures must usually be larger than competing fixtures, color cannot be distinguished — due to its emitting only a single wavelength of light (see security lighting) — and conflicts with yellow traffic lights are observed. Due to the substantial size of the light emitting part of the lamp, the arc tube, control of light emissions from low pressure sodium luminaires is very difficult resulting in higher amounts of light pollution from luminaires running these lamps than any other light source except fluorescent tubes. This has led many authorities to instead adopt more controllable high pressure sodium lighting for their street lights.
Because of the scatter of light by the atmosphere, particularly Rayleigh scattering, different sources produce dramatically different amounts of skyglow from the same amount of light sent into the atmosphere. A simple metric for this phenomenon is the Rayleigh Scatter Index, discussed in a brief article and a 2003 presentation to both the IDA Conference and the IESNA, which indicates that high pressure sodium produces roughly one-third to one-half of the skyglow that typical metal halide does, based on the same amount of light entering the atmosphere.
In some cases, evaluation of existing plans has determined that more efficient lighting plans are possible. For instance, light pollution can be reduced by turning off unneeded outdoor lights, and only lighting stadiums when there are people inside. Timers are especially valuable for this purpose.
One example of a lighting plan assessment can be seen in a report originally commissioned by the Office of the Deputy Prime Minister in the United Kingdom, and now available through the Department for Communities and Local Government.[36] The report details a plan to be implemented throughout the UK, for designing lighting schemes in the countryside, with a particular focus on preserving the environment.
In another example, the city of Calgary has recently replaced most residential street lights with models that are comparably energy efficient[37]. The motivation is primarily operation cost and environmental conservation. The costs of installation are expected to be regained through energy savings within six to seven years.
The Swiss agency for energy efficiency (SAFE) uses a concept which promises to be of great use in the diagnosis and design of road lighting, i.e. "consommation électrique spécifique (CES)", which can be translated into English as "specific electric power consumption (SEC)".[1] Thus, based on observed lighting levels in a wide range of Swiss towns, SAFE has defined target values for electric power consumption per metre for roads of various categories. Thus, SAFE currently recommends an SEC of 2 to 3 watts per meter for roads of less than 10 metre width (4 to 6 watts per metre for wider roads). Such a measure provides an easily applicable environmental protection constraint on conventional "norms", which usually are based on the recommendations of lighting manufacturing interests, who may not take into account environmental criteria. In view of ongoing progress in lighting technology, target SEC values will need to be periodically revised downwards.
Noise pollution (or environmental noise) is displeasing human or machine created sound that disrupts the activity or happiness of human or animal life. A common form of noise pollution is from transportation, principally motor vehicles.[1] The word "noise" comes from the Latin word nausea meaning "seasickness", or from a derivative (perhaps Latin noxia) of Latin noceō = "I do harm", referring originally to nuisance noise.[2]
Sources of noise
The source of most noise worldwide is transportation systems, principally motor vehicle noise, but also including aircraft noise and rail noise.[3][1] Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.
Other sources are office equipment, factory machinery, construction work, appliances, power tools, lighting hum and audio entertainment systems.
Noise from recreational vehicles has become a problem.[citation needed] ATVs, also known as quads, have increased in popularity and are joining the two wheeled dirt motorcycles for off-road riding. The noise produced by these vehicles is particularly disturbing due to the wide variations in frequency and volume.[citation needed]
Human health
Noise health effects are both health and behavioral in nature. The unwanted sound is called noise pollution. This unwanted sound can damage physiological and psychological health. Noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, and other harmful effects.[4][5] Furthermore, stress and hypertension are the leading causes to health problems, whereas tinnitus can lead to forgetfulness, severe depression and at times panic attacks.[5][6]
Hearing
The mechanism for chronic exposure to noise leading to hearing loss is well established. The elevated sound levels cause trauma to the cochlear structure in the inner ear, which gives rise to irreversible hearing loss.[4] A very loud sound in a particular frequency range can damage the cochlea's hair cells that respond to that range thereby reducing the ear's ability to hear those frequencies in the future.[7] However, loud noise in any frequency range has deleterious effects across the entire range of human hearing.[8]
The outer ear (visible portion of the human ear) combined with the middle ear amplifies sound levels by a factor of 20 when sound reaches the inner ear.[9]
In Rosen's work on health effects and hearing loss, one of his findings derived from tracking Maaban tribesmen, who were insignificantly exposed to transportation or industrial noise. This population was systematically compared by cohort group to a typical U.S. population. The findings proved that aging is an almost insignificant cause of hearing loss, which instead is associated with chronic exposure to moderately high levels of environmental noise.[4]
A landing Qantas Boeing 747-400 passes close to houses on the boundary of London Heathrow Airport, England
Cardiovascular health
High noise levels can contribute to cardiovascular effects and exposure to moderately high levels during a single eight hour period causes a statistical rise in blood pressure of five to ten points and an increase in stress[10] and vasoconstriction leading to the increased blood pressure noted above as well as to increased incidence of coronary artery disease.
Annoyance
Noise pollution is a cause of annoyance:
1. The meaning listeners attribute to the sound influences annoyance, so that, if listeners dislike the noise content, they are annoyed. What is music to one is noise to another.
2. If the sound causes activity interference, noise is more likely to annoy (for example, sleep disturbance)
3. If listeners feel they can control the noise source, the noise is less likely to be annoying.
4. If listeners believe that the noise is subject to third-party control, including police, but control has failed, they are more annoyed.
5. The inherent unpleasantness of the sound causes annoyance.6. Contextual sound. If the sound is appropriate for the activity it is in context. If one
is at a race track the noise is in context and the psychological effects are absent. If one is at an outdoor picnic the race track noise will produce adverse psychological and physical effects.
A 2005 study by Spanish researchers found that in urban areas households are willing to pay approximately four Euros per decibel per year for noise reduction.[11]
EnvironmentNoise can have a detrimental effect on animals by causing stress, increasing risk of mortality by changing the delicate balance in predator/prey detection and avoidance, and by interfering with their use of sounds in communication especially in relation to reproduction and in navigation. Acoustic overexposure can lead to temporary or permanent loss of hearing.[12]
Habitat reduction
An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. One of the best known cases of damage caused by noise pollution is the death of certain species of beached whales, brought on by the loud sound of military sonar.[13]
Lombard vocal response
Noise also makes species communicate louder, which is called Lombard vocal response.[14] Scientists and researchers have conducted experiments that show whales' song length is longer when submarine-detectors are on.[15] If creatures don't "speak" loud enough, their voice will be masked by anthropogenic sounds. These unheard voices might be warnings, finding of prey, or preparations of net-bubbling. When one species begins speaking louder, it will mask other species' voice, causing the whole ecosystem to eventually speak louder.
Other habit changes
Zebra finches become less faithful to their partners when exposed to traffic noise. This could alter a population's evolutionary trajectory by selecting "sexy" traits, sapping resources normally devoted to other activities and thus lead to profound genetic and evolutionary consequences.[16]
The sound tube in Melbourne, Australia, designed to reduce roadway noise without detracting from the area's aesthetics.
Technology to mitigate or remove noise can be applied as follows:
There are a variety of strategies for mitigating roadway noise including: use of noise barriers, limitation of vehicle speeds, alteration of roadway surface texture, limitation of heavy duty vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration and tire design. An important factor in applying these strategies is a computer model for roadway noise, that is capable of addressing local topography, meteorology, traffic operations and hypothetical mitigation. Costs of building-in mitigation can be modest, provided these solutions are sought in the planning stage of a roadway project.
Aircraft noise can be reduced to some extent by design of quieter jet engines, which was pursued vigorously in the 1970s and 1980s. This strategy has brought limited but noticeable reduction of urban sound levels. Reconsideration of operations, such as altering flight paths and time of day runway use, have demonstrated benefits for residential populations near airports. FAA sponsored residential retrofit (insulation) programs initiated in the 1970s has also enjoyed success in reducing interior residential noise in thousands of residences across the United States.
Exposure of workers to Industrial noise has been addressed since the 1930s. Changes include redesign of industrial equipment, shock mounting assemblies and physical barriers in the workplace.
Legal statusGovernments up until the 1970s viewed noise as a "nuisance" rather than an environmental problem. In the United States there are federal standards for highway and aircraft noise; states and local governments typically have very specific statutes on building codes, urban planning and roadway development. In Canada and the EU there are few national, provincial, or state laws that protect against noise.
Noise laws and ordinances vary widely among municipalities and indeed do not even exist in some cities. An ordinance may contain a general prohibition against making noise that is a nuisance, or it may set out specific guidelines for the level of noise allowable at certain times of the day and for certain activities.
Most city ordinances prohibit sound above a threshold intensity from trespassing over property line at night, typically between 10 p.m. and 6 a.m., and during the day restricts it to a higher sound level; however, enforcement is uneven. Many municipalities do not follow up on complaints. Even where a municipality has an enforcement office, it may only be willing to issue warnings, since taking offenders to court is expensive.
Many conflicts over noise pollution are handled by negotiation between the emitter and the receiver. Escalation procedures vary by country, and may include action in conjunction with local authorities, in particular the police. Noise pollution often persists because only five to ten percent of people affected by noise will lodge a formal complaint. Many people are not aware of their legal right to quiet and do not know how to register a complaint.
Thermal pollution is a temperature change in natural water bodies caused by human influence. The temperature change can be upwards or downwards. In the Northern Hemisphere, a common cause of thermal pollution is the use of water as a coolant, especially in power plants. Water used as a coolant is returned to the natural environment at a higher temperature. Increases in water temperature can impact on aquatic organisms by (a) decreasing oxygen supply, (b) killing fish juveniles which are vulnerable to small increases in temperature, and (c) affecting ecosystem composition. In the Southern Hemisphere, thermal pollution is commonly caused by the release of very cold water from the base of reservoirs, with severe affects on fish (particularly eggs and larvae), and river productivity.
Ecological effects — warm water
Warm water typically decreases the level of dissolved oxygen in the water. The decrease in levels of dissolved oxygen can harm aquatic animals such as fish, amphibians and copepods. Thermal pollution may also increase the metabolic rate of aquatic animals, as enzyme activity, resulting in these organisms consuming more food in a shorter time than if their environment were not changed. An increased metabolic rate may result in food source shortages, causing a sharp decrease in a population. Changes in the environment may also result in a migration of organisms to another, more suitable environment, and to in-migration of organisms that normally only live in warmer waters elsewhere. This leads to competition for fewer resources; the more adapted organisms moving in may have an advantage over organisms that are not used to the warmer temperature. As a result one has the problem of compromising food chains of the old and new environments. Biodiversity can be decreased as a result.
Fish killed in receiving waters
It is known that temperature changes of even one to two degrees Celsius can cause significant changes in organism metabolism and other adverse cellular biology effects. Principal adverse changes can include rendering cell walls less permeable to necessary osmosis, coagulation of cell proteins, and alteration of enzyme metabolism. These cellular level effects can adversely affect mortality and reproduction.
Primary producers are affected by warm water because higher water temperature increases plant growth rates, resulting in a shorter lifespan and species overpopulation. This can cause an algae bloom which reduces the oxygen levels in the water. The higher plant density leads to an increased plant respiration rate because the reduced light intensity decreases photosynthesis. This is similar to the eutrophication that occurs when watercourses are polluted with leached agricultural inorganic fertilizers.
A large increase in temperature can lead to the denaturing of life-supporting enzymes by breaking down hydrogen- and disulphide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as the inability to break down lipids, which leads to malnutrition.In limited cases, warm water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is seen especially in seasonal waters and is known as thermal enrichment. An extreme case is derived from the aggregational habits of the manatee, which often uses power plant discharge sites during winter. Projections suggest that manatee populations would decline upon the removal of these discharges.
The added heat lowers the dissolved oxygen content and may cause serious problems for the plants and animals living there. In extreme cases, major fish kills can result. Warm water may also increase the metabolic rate of aquatic animals, as enzyme activity, meaning that these organisms will consume more food in a shorter time than if their environment was not changed.
Ecological effects — cold water
Releases of unnaturally cold water from reservoirs can dramatically change the fish and macroinvertebrate fauna of rivers, and reduce river productivity. In Australia, where many rivers have warmer temperature regimes, native fish species have been eliminated, and macroinvertebrate faunas have been drastically altered and impoverished.
Computer modeling of thermal pollution
In the 1970s there was considerable activity from scientists in quantifying effects of thermal pollution. Hydrologists, physicists, meteorologists, and computer scientists combined their skills in one of the first interdisciplinary pursuits of the modern environmental science era. First came the application of gaussian function dispersal modeling that forecasts how a thermal plume is formed from a thermal point source and predicts the distribution of aquatic temperatures. The ultimate model was developed by the U.S. Environmental Protection Agency introducing the statistical variations in meteorology to predict the resulting plume from a thermal outfall.
Radioactive contamination is the uncontrolled distribution of radioactive material in a given environment. The amount of radioactive material released in an accident is called the source term.
Sources of contamination
Radioactive contamination is typically the result of a spill or accident during the production or use of radionuclides (radioisotopes), an unstable nucleus which has excessive energy.Contamination may occur from radioactive gases, liquids or particles. For example, if a radionuclide used in nuclear medicine is accidentally spilled, the material could be spread by people as they walk around. Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactive xenon in nuclear fuel reprocessing. In cases that radioactive material cannot be contained, it may be diluted to safe concentrations. Nuclear fallout is the distribution of radioactive contamination by a nuclear explosion. For a discussion of environmental contamination by alpha emitters please see actinides in the environment. Containment is what differentiates radioactive material from radioactive contamination. Therefore, radioactive material in sealed and designated containers is not properly referred to as contamination, although the units of measurement might be the same.
Measurement
Radioactive contamination may exist on surfaces or in volumes of material or air. In a nuclear power plant, detection and measurement of radioactivity and contamination is often the job of a Certified Health Physicist.
Surface contamination is usually expressed in units of radioactivity per unit of area. For SI, this is becquerels per square meter (or Bq/m²). Other units such as picoCuries per 100 cm² or disintegrations per minute per square centimeter (1 dpm/cm² = 166 2/3 Bq/m²) may be used. Surface contamination may either be fixed or removable. In the case of fixed contamination, the radioactive material cannot by definition be spread, but it is still measurable.
Hazards
In practice there is no such thing as zero radioactivity. Not only is the entire world constantly bombarded by cosmic rays, but every living creature on earth contains significant quantities of carbon-14 and most (including humans) contain significant quantities of potassium-40. These tiny levels of radiation are not any more harmful than sunlight, but just as excessive quantities of sunlight can be dangerous, so too can excessive levels of radiation.
Low level contamination
The hazards to people and the environment from radioactive contamination depend on the nature of the radioactive contaminant, the level of contamination, and the extent of the spread of contamination. Low levels of radioactive contamination pose little risk, but can still be detected by radiation instrumentation. In the case of low-level contamination by isotopes with a short half-life, the best course of action may be to simply allow the material to naturally decay. Longer-lived isotopes should be cleaned up and properly disposed off, because even a very low level of radiation can be life-threatening when in long exposure to it. Therefore, whenever there's any radiation in an area, many people take extreme caution when approaching.
Unintentionally released radiation can reach humans by a variety of means.
High levels of contamination may pose major risks to people and the environment. People can be exposed to potentially lethal radiation levels, both externally and internally, from the spread of contamination following an accident (or a deliberate initiation) involving large quantities of radioactive material. The biological effects of external exposure to radioactive contamination are generally the same as those from an external radiation source not involving radioactive materials, such as x-ray machines, and are dependent on the absorbed dose.
Biological effects
The biological effects of internally deposited radionuclides depend greatly on the activity and the biodistribution and removal rates of the radionuclide, which in turn depends on its chemical form. The biological effects may also depend on the chemical toxicity of the deposited material, independent of its radioactivity. Some radionuclides may be generally distributed throughout the body and rapidly removed, as is the case with tritiated water. Some radionuclides may target specific organs and have much lower removal rates. For instance, the thyroid gland takes up a large percentage of any iodine that enters the body. If large quantities of radioactive iodine are inhaled or ingested, the thyroid may be impaired or destroyed, while other tissues are affected to a lesser extent. Radioactive iodine is a common fission product; it was a major component of the radiation released from the Chernobyl disaster, leading to many cases of pediatric thyroid cancer and hypothyroidism. On the other hand, radioactive iodine is used in the diagnosis and treatment of many diseases of the thyroid precisely because of the thyroid's selective uptake of iodine.
Means of contaminationRadioactive contamination can enter the body through ingestion, inhalation, absorption, or injection. For this reason, it is important to use personal protective equipment when working with radioactive materials. Radioactive contamination may also be ingested as the result of eating contaminated plants and animals or drinking contaminated water or milk from exposed animals. Following a major contamination incident, all potential pathways of internal exposure should be considered.
