Toxic air pollutants, also called Hazardous Air Pollutants (HAPs), are known or suspected to cause adverse health or environmental effects. Most air toxics originate from human activities such as vehicle emissions, factories, solvents, etc. The Clean Air Act (CAA) requires EPA to regulate emissions of toxic air pollutants from a published list of industrial sources referred to as "source categories." These sources must meet control technology requirements for toxic air pollutants.

The EPA is required to develop regulations for all industries that emit one or more of the pollutants in significant quantities. Ambient Air Toxic Monitoring is an important part of the efforts to control air toxics pollutant which consists of both national and community-scale programs. The ATMN consists of three separate monitoring programs: The Urban Air Toxics Monitoring Network (UATM), The National Air Toxics Trends Stations (NATTS), and The Community Assessment Monitoring program (CAMP).

The Virginia Department of Environmental Quality currently operates two ambient air toxics monitoring programs in Virginia:

The Air Toxics Monitoring Steering Committee was established in 1999 to oversee the development of a national air toxics monitoring network. In 2002, EPA deployed the National Air Toxics Trends Stations (NATTS) network. The objective for the NATTS network is to provide long-term monitoring data for a limited number of air toxics across representative areas of the country in order to establish overall trends for these pollutants.  The required pollutants included Volatile Organic Compounds (VOCs), Carbonyls, PM10 metals, Hexavalent chromium, and Polycyclic Aromatic Hydrocarbons (PAHs). 

The NATTS network currently consists of 27 sites (20 urban, 7 rural) across the United States.  In July 2008, the Virginia Department of Environmental Quality began operating a NATTS located at the MathScience Innovation Center, 2401 Hartman Street, Richmond.    

Sampling at the UATM sites consists of ambient air samples. These samples take three different forms. The first is ambient air samples collected in canisters for the capture of VOCs. The second is ambient air drawn through DNPH treated cartridges to collect Carbonyls. The third form passes ambient air through quartz filters to collect a range of particulate matter.

The above laboratories have been designated as the EPA region III laboratories for their respective analysis.

Additional information

The Plain English Guide to the Clean Air Act (CAA) is a web site maintained by the EPA. This web site can be found at http://www.epa.gov/airquality/peg_caa/index.html. This web site attempts to demystify the CAA and use plain English to explain the requirements set forth in the CAA.

Methods of analysis may be viewed by clicking on the following links:

• Volatile Organic Compounds (VOCs) by TO-14 (PDF)
• Volatile Organic Compounds (VOCs) by TO-15
• Carbonyls by TO-11A
• TSP Metals by IO-3.5

Questions concerning any variations to the above methods would need to be directed to the laboratory performing the specific analysis located below.

Questions concerning the DEQ Ambient Air Toxics Monitoring Program should be directed to:

Baxter Gilley
Office of Air Quality Monitoring
4949-C Cox Road
Glen Allen, VA 23060
Voice: 804-527-5188
Fax: 804-527-5160
Email: Baxter.Gilley@deq.virginia.gov