Health Aspects of Air Toxics

Human exposure to toxic air pollutants can include short-term (acute) and long-term (chronic) effects. Many factors impact how different toxic air pollutants affect human health, including the quantity of the toxin to which a person is exposed, the duration and frequency of the exposure, the toxicity level of the pollutant, and the person’s overall health and level of resistance or susceptibility. Short-term exposures can include effects such as eye irritation, nausea, or difficulty in breathing. Long-term exposures may result in damage to the respiratory or nervous systems, birth defects, and reproductive effects.

Toxic air pollution is a health concern both in the vicinity of the emitting source and beyond. Toxic pollutants emitted from a source may be transported by the air far from the source to diverse areas of the world. As a result, local air toxic pollution may be the product of, or be aggravated by, both local sources of air toxics and more distant sources.

Exposure to air toxics is not limited to breathing in the pollutants. Some toxic air pollutants, like mercury, can be deposited into soil and water where it is then delivered into the systems of plants and animals. The mercury then travels up through the food chain, a process called bioaccumulation (PDF 2.28 MB). Animals also experience significant health problems if exposed to air toxics.The U. S. EPA has published the following documents containing additional information about the health effects of air toxics:

Air Pollution and Health Risk
How do we know when a risk from a hazardous substance is serious? This brochure shows how researchers estimate risk, and how the government uses this information to develop regulations that limit our exposure to hazardous substances. Also available in Spanish.

Evaluating Exposure to Toxic Air Pollutants: A Citizen’s Guide
Toxic air pollutants can increase the chance of health problems and cause ecological impacts. This brochure discusses the process used to determine how much of a toxic air pollutant people are exposed to and how many people are exposed. Also available in Spanish.

Risk Assessment for Toxic Air Pollutants: A Citizen’s Guide
Risk assessment is a process used to estimate the risk of illness from a specific human exposure to a toxic air pollutant. This brochure gives an overview of EPA’s 4-step assessment process. Also available in

Taking Toxics Out of the Air
This document describes what air toxics are, where they come from, and how they can impact people and the environment. It also describes the steps being taken by the U.S. Environmental Protection Agency to reduce emissions of air toxics from major industrial sources such as chemical manufacturing plants, petroleum refineries, and steel manufacturing plants.