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Environmental Health

Dr. Latefa Dardas

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Environmental Health

Environmental health addresses all the physical, chemical, and biological factors external to a person, and all the related factors impacting behaviors. It encompasses the assessment and control of those environmental factors that can potentially affect health. It is targeted towards preventing disease and creating health-supportive environments. This definition excludes behavior not related to environment, as well as behavior related to the social and cultural environment, and genetics.

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Content

Air Pollution Chemical SafetyWater Sanitation Hygiene Environmental Health in Emergencies Climate Change

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Air Pollution (update 2018) WHO estimates that around 90% of people worldwide breathe polluted air. Over

the past 6 years, ambient air pollution levels have remained high and approximatively stable, with declining concentrations in some part of Europe and in the Americas.

The highest ambient air pollution levels are in the Eastern Mediterranean Region and in South-East Asia, with annual mean levels often exceeding more than 5 times WHO limits, followed by low and middle-income cities in Africa and the Western Pacific.

Africa and some of the Western Pacific have a serious lack of air pollution data. For Africa, the database now contains PM measurements for more than twice as many cities as previous versions, however data was identified for only 8 of 47 countries in the region.

Europe has the highest number of places reporting data.

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Air Pollution (update 2018)

In general, ambient air pollution levels are lowest in high-income countries, particularly in Europe, the Americas and the Western Pacific. In cities of high-income countries in Europe, air pollution has been shown to lower average life expectancy by anywhere between 2 and 24 months, depending on pollution levels.

Air pollution causes 1 in 9 deaths worldwide.

Most air pollution-related deaths are from non-communicable diseases (NCDs). In terms of global disease burden, air pollution is the cause of over one-third of deaths from stroke, lung cancer, and chronic respiratory disease, and one-quarter of deaths from ischemic heart disease.

Required Video https://www.youtube.com/watch?v=GVBeY1jSG9Y&feature=youtu.beD

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Chemical Safety

Chemical safety is achieved by undertaking all activities involving chemicals in such a way as to ensure the safety of human health and the environment. It covers all chemicals, natural and manufactured, and the full range of exposure situations from the natural presence of chemicals in the environment to their extraction or synthesis, industrial production, transport, use and disposal.

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• Ten chemicals of major public health concern:

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Poisoning Prevention and Management

Poisoning is a significant global public health problem. According to WHO data, in 2012 an estimated 193,460 people died worldwide from unintentional poisoning. Of these deaths, 84% occurred in low- and middle-income countries. In the same year, unintentional poisoning caused the loss of over 10.7 million years of healthy life (disability adjusted life years, DALYs).

Nearly a million people die each year as a result of suicide, and chemicals account for a significant number of these deaths. For example, it is estimated that deliberate ingestion of pesticides causes 370,000 deaths each year. The number of these deaths can be reduced by limiting the availability of, and access to, highly toxic pesticides.

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Food Safety and Chemical Risks

Chemicals can end up in food either intentionally added for a technological purpose (e.g. food additives), or through environmental pollution of the air, water and soil. Chemicals in food are a worldwide health concern and are a leading cause of trade obstacles.

WHO develops scientific risk assessments to define safe exposure levels which form the basis for the development of national and international food safety standards to protect the health of the consumers and ensure fair trade practices.

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Highly Hazardous Pesticides

Highly hazardous pesticides may have acute and/or chronic toxic effects, and pose particular risk to children. Their widespread use has caused health problems and fatalities in many parts of the world, often as a result of occupational exposure and accidental or intentional poisonings.

Available data are too limited to estimate the global health impacts of pesticides, however the global impact of self-poisoning (suicides) from preventable pesticide ingestion has however been estimated to amount over years.

Environmental contamination can also result in human exposure through consumption of residues of pesticides in food and, possibly, drinking water. While developed countries have systems already in place to register pesticides and control their trade and use, this is not always the case elsewhere. Guidance and legal frameworks on the use, management and trade of pesticides, as well as proper storage and handling, are available from international organizations and international conventions; these should be implemented globally.

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Water Sanitation Hygiene

Safe and readily available water is important for public health, whether it is used for drinking, domestic use, food production or recreational purposes. Improved water supply and sanitation, and better management of water resources, can boost countries’ economic growth and can contribute greatly to poverty reduction.

89% of the global population (6.5 billion people) used at least a basic service. A basic service is an improved drinking-water source within a round trip of 30 minutes to collect water.

Globally, at least 2 billion people use a drinking water source contaminated with faeces.

By 2025, half of the world’s population will be living in water-stressed areas.

In low- and middle-income countries, 38% of health care facilities lack an improved water source, 19% do not have improved sanitation, and 35% lack water and soap for handwashing.

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Water Sanitation Hygiene

Contaminated water and poor sanitation are linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio. Absent, inadequate, or inappropriately managed water and sanitation services expose individuals to preventable health risks. This is particularly the case in health care facilities where both patients and staff are placed at additional risk of infection and disease when water, sanitation, and hygiene services are lacking. Globally, 15% of patients develop an infection during a hospital stay, with the proportion much greater in low-income countries.

Diarrhoea is the most widely known disease linked to contaminated food and water but there are other hazards. Almost 240 million people are affected by schistosomiasis – an acute and chronic disease caused by parasitic worms contracted through exposure to infested water.

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Water Sanitation Hygiene

In many parts of the world, insects that live or breed in water carry and transmit diseases such as dengue fever. Some of these insects, known as vectors, breed in clean, rather than dirty water, and household drinking water containers can serve as breeding grounds. The simple intervention of covering water storage containers can reduce vector breeding and may also reduce faecal contamination of water at the household level.

With children particularly at risk from water-related diseases, access to improved sources of water can result in better health, and therefore better school attendance, with positive longer-term consequences for their lives.

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WHO Guidelines for Drinking-Water Quality

http://apps.who.int/iris/bitstream/handle/10665/254637/9789241549950-eng.pdf;jsessionid=187EDF3FBB947694EA354C5F95AC089D?sequence=1

These are FYI, not for exam.

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Environmental Health in Emergencies Emergencies, conflicts, and disasters happen frequently, including natural disasters,

chemical or radiological incidents, complex emergencies, and deliberate events. A substantial fraction of the disease burden derived from these events is attributable to environmental risk factors.

A natural disaster is an act of nature of such magnitude as to create a catastrophic situation in which the day-to-day patterns of life are suddenly disrupted and people are plunged into helplessness and suffering, and, as a result, need food, clothing, shelter, medical and nursing care and other necessities of life, and protection against unfavourable environmental factors and conditions.

• Complex emergencies combine internal conflict with large-scale displacements of people, mass famine or food shortage, and fragile or failing economic, political, and social institutions. Often, complex emergencies are also exacerbated by natural disasters.

• Deliberate events cover a wide spectrum of intent and public health impact. They can be on a small scale, for example, contaminating a few samples of a product to extort money from a retailer. They can also be on a large scale, such as the deliberate release of biological, chemical or radionuclear material for terrorist purposes. 16

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Environmental Health in Emergencies

Children, pregnant women, elderly people, malnourished people, and people who are ill or immunocompromised, are particularly vulnerable when a disaster strikes, and take a relatively high share of the disease burden associated with emergencies. Poverty – and its common consequences such as malnutrition, homelessness, poor housing and destitution – is a major contributor to vulnerability.

Vulnerability is the degree to which a population, individual or organization is unable to anticipate, cope with, resist and recover from the impacts of disasters. Environmental health in emergencies and disasters: a practical guide (WHO, 2002).

Political turbulence in many regions of the world has increased the number of displaced people fleeing complex emergencies and disasters. They often end up in large camps where environmental health measures are insufficient. Displaced people include internally displaced people (people who remain in their own countries) as well as refugees (people who cross international borders).

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Climate Change and Health

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Climate Change Over the last 50 years, human activities – particularly the burning of fossil fuels – have

released sufficient quantities of carbon dioxide and other greenhouse gases to trap additional heat in the lower atmosphere and affect the global climate.

In the last 130 years, the world has warmed by approximately 0.85oC. Each of the last 3 decades has been successively warmer than any preceding decade since 1850(1).

Sea levels are rising, glaciers are melting and precipitation patterns are changing. Extreme weather events are becoming more intense and frequent.

What is the impact of climate change on health? Although global warming may bring some localized benefits, such as fewer winter deaths in temperate climates and increased food production in certain areas, the overall health effects of a changing climate are likely to be overwhelmingly negative. Climate change affects social and environmental determinants of health – clean air, safe drinking water, sufficient food and secure shelter.

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Climate Change Between 2030 and 2050, climate change is expected to cause approximately 250

000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress.

The direct damage costs to health (i.e. excluding costs in health-determining sectors such as agriculture and water and sanitation), is estimated to be between USD 2-4 billion/year by 2030.

Areas with weak health infrastructure – mostly in developing countries – will be the least able to cope without assistance to prepare and respond.

Reducing emissions of greenhouse gases through better transport, food and energy-use choices can result in improved health, particularly through reduced air pollution.

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Climate Change

• Extreme heat:

• Extreme high air temperatures contribute directly to deaths from cardiovascular and respiratory disease, particularly among elderly people. In the heat wave of summer 2003 in Europe for example, more than 70 000 excess deaths were recorded.

• High temperatures also raise the levels of ozone and other pollutants in the air that exacerbate cardiovascular and respiratory disease.

• Pollen and other aeroallergen levels are also higher in extreme heat. These can trigger asthma, which affects around 300 million people. Ongoing temperature increases are expected to increase this burden.

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Natural Disasters and Variable Rainfall Patterns

• Globally, the number of reported weather-related natural disasters has more than tripled since the 1960s. Every year, these disasters result in over 60 000 deaths, mainly in developing countries.

• Rising sea levels and increasingly extreme weather events will destroy homes, medical facilities and other essential services. More than half of the world's population lives within 60 km of the sea. People may be forced to move, which in turn heightens the risk of a range of health effects, from mental disorders to communicable diseases.

• Increasingly variable rainfall patterns are likely to affect the supply of fresh water. A lack of safe water can compromise hygiene and increase the risk of diarrhoeal disease, which kills over 500 000 children aged under 5 years, every year. In extreme cases, water scarcity leads to drought and famine. By the late 21st century, climate change is likely to increase the frequency and intensity of drought at regional and global scale.

• Floods are also increasing in frequency and intensity, and the frequency and intensity of extreme precipitation is expected to continue to increase throughout the current century.

• Rising temperatures and variable precipitation are likely to decrease the production of staple foods in many of the poorest regions. This will increase the prevalence of malnutrition and undernutrition, which currently cause 3.1 million deaths every year.

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Patterns of Infection

• Climatic conditions strongly affect water-borne diseases and diseases transmitted through insects, snails or other cold blooded animals.

• Changes in climate are likely to lengthen the transmission seasons of important vector-borne diseases and to alter their geographic range. For example, climate change is projected to widen significantly the area of China where the snail-borne disease schistosomiasis occurs.

• Malaria is strongly influenced by climate. The Aedes mosquito vector of dengue is also highly sensitive to climate conditions, and studies suggest that climate change is likely to continue to increase exposure to dengue.

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Why Environmental Health

By focusing on reducing environmental and social risk factors, nearly a quarter of the global burden of disease can be prevented. Examples include promoting safe household water storage, better hygiene measures, safer management of toxic substances in the home and workplace.

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