Air Pollution
Air pollution is produced by atmospheric contaminants.  Air pollution can have large negative effects on human health and has recently been recognized as an international health problem.

Asbestos
Asbestos is a natural fibrous mineral found in soil throughout the world.  Once common as a construction material, it can be very harmful to human beings upon inhalation or digestion.

Agency for Toxic Substances and Disease Registry (ATSDR)
The Agency for Toxic Substances and Disease Registry, known as the ATSDR, was established in 1980 to conduct health studies on the effects of hazardous substances and to compile and maintain a registry of individuals exposed to toxic chemicals.

Auto Emissions
The automobile is a primary source of hazardous air pollution.  Emissions of carbon monoxide are especially dangerous.

Biocontaminants
Biological contaminants are a form of air pollution, present particularly in the indoor air that humans breathe.

Birth Defects
Birth defects are physical or physiological abnormalities that exist at  the time of birth.  Many birth defects can be attributed to chemicals present in the environment.

Carcinogen
A carcinogen is defined as any substance that causes cancer.  Many chemicals and substances in the environment act as carcinogens.

Cholera
Cholera is a disease transmitted though water.  It can be caused by toxic contaminants and can pose a number of very serious health risks.

DDT
Dichlorodiphenyl-trichloroethane --  commonly known as DDT -- is a controversial insecticide.  It has served as both a as aid and an even more as a hindrance to public health.

Famine
Famine is defined as the starvation of a population of people.  It can result from overpopulation and natural and environmental disasters.

Fertilizer
Nitrogen fertilizer is an effective and very widely used means of increasing crop yields in agriculture.  However, its common use, along with that of animal manure, has lead to the greater contamination of surface and groundwater with nitrates.

Formaldehyde Gas
Formaldehyde is a chemical once used widely in construction.  Gases coming from this substance can be very health hazardous.

Global Warming
Global warming is predicted to have a large effect on temperatures and weather patterns.  It will therefore also greatly impact human health though a number of direct and indirect measures.

Irrigation
Irrigation techniques have greatly enhanced agricultural output.  There are several environmental as well as health problems relating to irrigation.

Landfills
Landfills are used for the disposal of a variety of solid wastes.  However, due to the many health hazards involved with such massive deposits of sometimes-toxic waste, governments have been forced many landfills to close.

Lead
Lead is one the oldest and most prevalent poisons found in the earth's air.  Lead inhalation produces serious heath problems, ranging form lowered IQs to heart disease.

Malnutrition
Throughout the world, malnutrition claims millions of lives.  While one leading cause is poverty, many environmental issues also produce malnutrition.

Mines and Quarries
Mines and quarries, both in and out of use, can be serious human health threats. Mines are operations that involve the removal and extraction of specific substances; quarries only remove bulk material without extraction.

Nuclear Power Plants
Many problems can come about with nuclear power plants.  Radiation, accidents, and other problems can all create health threats.

Ozone Layer Depletion
Ozone Layer depletion occurs mainly as a result of overuse of the chemicals, chlorofluorocarbons, or CFCs.  The destruction of the ozone layer will harm human health in several ways.

Petroleum Storage Terminals
Petroleum storage terminals are storage areas for a variety of petroleum products.  If these materials are allowed to contaminant the surrounding environment, the effects can be very hazardous.

Radon
Radon is a gas that is produced by the breakdown, or radioactive decay, of uranium naturally found in most earth materials.  It is a colorless, odorless, and tasteless gas that can greatly increase the risk of lung cancer.

Sewage Treatment Plants
Wastewater that is sent through the sewer system is supposed to come out clean, but the actual practices of the waste-purification process can be health hazardous.

Superfund Sites
Superfund Sites are a classification of serious hazardous waste disposal sites.  These areas are locations that are in severe need of cleanup due to environmental and health risks resulting from toxic wastes.

Water Pollution
A variety of sources can pollute the water.  Especially when the water is not properly cleaned and treated, this pollution can have major impacts on human health.