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Introduction.
Hazards can present themselves to us in various media e.g. air, water. The influence they can exert on our health is very complex and may be modulated by our genetic make up, psychological factors and by our perceptions of the risks that they present.
The following deals with general environmental health hazards, and not extremes of climate, occupational hazards, hazards associated with food, most "accidents" or sexually transmitted disease.
Physical Hazards, and their Adverse Health Effects
Important issues concerning physical hazards include those relating to health effects of electromagnetic radiation and ionizing radiation. If one excludes the occupational environment, then noise and other physical hazards may present a nuisance to many inhabitants, and impair general well being. Environmental noise does not usually contribute to deafness but notable exceptions may include noisy discotheques and "personal stereos".
Chemical Hazards, and their Adverse Health Effects
Identifying a specific chemical as the "original cause" of these health disorders is difficult and often overlooked as it typically requires years of exposure for the body's inherent defenses to weaken sufficiently to result in observable health problems.
Potential air pollution-related health effects of climate change
OZONE HEALTH IMPACTS:
PYRAMID OF EFFECTS
PROPORTION OF POPULATION AFFECTED
In Organic Pollutants
Inorganic health effects
Cd is a cumulative toxicant that affects kidneys, bone metabolism and the reproductive tract, and it is also carcinogenic and an endocrine disruptor.
Pb has strong effects on haem biosynthesis and erythropoiesis and kidney
As, There is convincing evidence from a large number of epidemiological and laboratorial studies that ingestion of inorganic arsenic significantly increases the risk of developing skin cancer and other internal organ cancers, such as the liver, lung, bladder, kidney, colon and prostate gland (Tchounwou et al., 2003; Rossman et al., 2004).
Inorganic health effects
Methylmercury in our food is promptly absorbed in the gastrointestinal track, immediately entering the blood stream. The severe damage of the central nervous system (CNS) caused by methylmercury and also elemental Hg exposure is due to their ability to cross the blood-brain barrier.