There are currently 188 hazardous air pollutants (HAPs), or Air Toxics (AT), regulated under the Clean Air Act (CAA) that have been associated with a wide variety of adverse health effects, including cancer, neurological effects, reproductive effects and developmental effects, as well as ecosystem effects. These air toxics are emitted from multiple sources, including major stationary, area, and mobile sources, resulting in population exposure to these air toxics as they occur in the environment. While in some cases the public may be exposed to an individual HAP, more typically people experience exposures to multiple HAPs and from many sources. Exposures of concern result not only from the inhalation of these HAPs, but also, for some HAPs, from multipathway exposures to air emissions. For example, air emissions of mercury are deposited in water and people are exposed to mercury through their consumption of contaminated fish.

Project Officer: Sharon Nizich. "Quality Management Plan for the National Air Toxics Trends Stations Monitoring Program."--Technical report data. "December 2002." "EPA 454/R-02-006."

The Quality Management Plan for the National Air Toxics Trends Stations details the management structure National Air Toxics Trends monitoring program. The guidance document gives details on which organizations will be involved with the national program. It details the responsibilities and rights of each organization that will be involved in the national trends network. It also discusses the data management and storage of the long term data. An important discussion point is the Quality Assurance Assessment and Improvement System.