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Technology Transfer Network - Air Toxics Web Site

About Air Toxics

What are toxic air pollutants?

Toxic air pollutants, also known as hazardous air pollutants, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects. EPA is working with state, local, and tribal governments to reduce air toxics releases of 187 pollutants to the environment. Examples of toxic air pollutants include benzene, which is found in gasoline; perchloroethylene, which is emitted from some dry cleaning facilities; and methylene chloride, which is used as a solvent and paint stripper by a number of industries. Examples of other listed air toxics include dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead compounds.

What are the health and environmental effects of toxic air pollutants?

People exposed to toxic air pollutants at sufficient concentrations and durations may have an increased chance of getting cancer or experiencing other serious health effects. These health effects can include damage to the immune system, as well as neurological, reproductive (e.g., reduced fertility), developmental, respiratory and other health problems. In addition to exposure from breathing air toxics, some toxic air pollutants such as mercury can deposit onto soils or surface waters, where they are taken up by plants and ingested by animals and are eventually magnified up through the food chain. Like humans, animals may experience health problems if exposed to sufficient quantities of air toxics over time.

Where do toxic air pollutants come from?

Most air toxics originate from human-made sources, including mobile sources (e.g., cars, trucks, buses) and stationary sources (e.g., factories, refineries, power plants), as well as indoor sources (e.g., some building materials and cleaning solvents). Some air toxics are also released from natural sources such as volcanic eruptions and forest fires.

How are people exposed to air toxics?

People are exposed to toxic air pollutants in many ways that can pose health risks, such as by:

  • Breathing contaminated air.
  • Eating contaminated food products, such as fish from contaminated waters; meat, milk, or eggs from animals that fed on contaminated plants; and fruits and vegetables grown in contaminated soil on which air toxics have been deposited.
  • Drinking water contaminated by toxic air pollutants.
  • Ingesting contaminated soil. Young children are especially vulnerable because they often ingest soil from their hands or from objects they place in their mouths.
  • Touching (making skin contact with) contaminated soil, dust, or water (for example, during recreational use of contaminated water bodies).

Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body tissues. Predators typically accumulate even greater pollutant concentrations than their contaminated prey. As a result, people and other animals at the top of the food chain who eat contaminated fish or meat are exposed to concentrations that are much higher than the concentrations in the water, air, or soil.

Can I find out about the toxics in my community?

  • National Air Toxics Assessment -- This site provides emissions and health risk information on 33 air toxics that present the greatest threat to public health in the largest number of urban areas. Maps and lists are available and can be requested by state or county level.
  • Toxics Release Inventory -- This database includes information for the public about releases of toxic chemicals from manufacturing facilities into the environment through the air, water, and land. You can access the data by typing in your zip code.

What progress has EPA made in reducing toxic emissions?

  • Controls for industrial and commercial sources of toxics -- EPA has issued rules covering over 80 categories of major industrial sources, such as chemical plants, oil refineries, aerospace manufacturers, and steel mills, as well as categories of smaller sources, such as dry cleaners, commercial sterilizers, secondary lead smelters, and chromium electroplating facilities. These standards are projected to reduce annual air toxics emissions by about 1.5 million tons. For more information about these rules, see Taking Toxics Out of the Air.
  • Controls for cars and trucks -- EPA and state governments (e.g., California) have reduced emissions of benzene, toluene, and other air toxics from mobile sources by requiring the use of reformulated gasoline and placing limits on tailpipe emissions. Important new controls for fuels and vehicles are expected to reduce selected motor vehicle air toxics from 1990 levels by more than 75% by 2020. For more information, see Mobile Source Air Toxics.
  • Indoor air -- EPA, in close cooperation with other Federal agencies and the private sector, is actively involved in efforts to better understand indoor air pollution and to reduce people's exposure to air pollutants in offices, homes, schools, and other indoor environments. For more information, see Indoor Air Quality.

Health and ecological effects resources

  • The Health Effects Notebook for Hazardous Air Pollutants -- Detailed information about the health effects of hazardous air pollutants (HAPs) is available in separate fact sheets, for nearly every HAP specified in the Clean Air Act Amendments of 1990.
  • Mercury -- Learn more about mercury and what is being done to protect your health.
  • Air Pollution and Health Risk -- Find out how we know when a risk from a hazardous substance is serious. Learn how researchers estimate risk, and how the government uses this information to develop regulations that limit our exposure to hazardous substances.
  • Evaluating Exposures to Toxic Air Pollutants: A Citizen's Guide -- Toxic air pollutants can increase the chance of health problems and cause ecological impacts. This publication explains the process that EPA uses to determine how much of a toxic air pollutant people are exposed to and how many people are exposed.
  • Risk Assessment for Toxic Air Pollutants: A Citizen's Guide -- Find out more about risk assessment, which is the process used to estimate the risk of illness from a specific human exposure to a toxic air pollutant.
  • Taking Toxics Out of the Air -- This brochure describes what air toxics are, where they come from, and how they impact people and the environment.

Links to other air toxics resources

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