Technologies for the 21st Century Air Quality

	Fine particles and health Community Multi-scale Air Quality model Ozone and sulfate concentrations
Fine particles and health	Scientific studies have linked fine particles (less than 2.5 microns) produced by wood stoves, agricultural burning, and conversion of gases from fuel combustion to health problems such as aggravated asthma, chronic bronchitis, and severe chest pain. The elderly suffering from lung or heart disease and active children are most at risk from inhaling these fine particles. Asthmatic children and even healthy adults face an additional health risk from exposure to ground level ozone, a major ingredient of urban smog.
Community Multi-scale Air Quality model	To protect against these health risks, the Environmental Protection Agency (EPA) has proposed revisions to the Particulate Matter and Ozone National Ambient Air Quality Standards (NAAQS). States found in violation of these standards are required to prepare individual state implementation plans and perform air quality modeling studies to demonstrate how they will meet the NAAQS. Advanced computational techniques have enabled the development of a Community Multi-scale Air Quality (CMAQ) model to compute hourly ozone and fine-particle concentrations simultaneously as part of a "one atmosphere" approach to exposure and risk assessment. Models-3, an environmental problem-solving framework built upon information management and distributed computing technology, enables state and local/regional air pollution control managers as well as local industry to use these comprehensive multipollutant models to assist in environmental decision-making that affects the health, economic well-being, and quality of life in their communities.
Ozone and sulfate concentrations	Although ozone chemistry and sulfate particle formation are linked, changes in source emis-sions can influence ozone and sulfate concentrations differently. For this reason, knowledge of concurrent production of ozone and fine particles is critical. In the illustration, predicted ozone levels that meet the existing National Ambient Air Quality Standards but exceed the proposed revised standards are shown in blue. The green areas show high sulfur dioxide con-centrations directly over large industrial sources, and the yellow plumes depict sulfate that was transformed from ground sources of sulfur dioxide and transported long distances by prevailing winds.