NARSTO_EPA_SS_LOS_ANGELES_TEOM_PM25_DATA is the North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Los Angeles Tapered-Element Oscillating Microbalance (TEOM) Particulate Matter (PM) 2.5 Mass Concentration Data. It was collected between December 2000 and September 2002 using a Tapered-Element Oscillating Microbalance (TEOM). At Downey and Riverside (Los Angeles County, California), the standard TEOM Model 1400a was used in a mobile trailer to collect PM2.5 mass concentration data every 30 minutes during December 19, 2000 to May 22, 2001. At Claremont and Rubidoux (Los Angeles County, California), Differential TEOM (proto-type) was used in a mobile trailer to collect hourly PM2.5 mass concentration data during August 17, 2001 to September 3, 2002. The overall objective of the Los Angeles Super Site in Southern California Particle Center and Supersite (SCPCS) is to conduct monitoring and research that contributes to a better understanding of the measurement, sources, size distribution, chemical composition and physical state, spatial and temporal variability, and linkages to health effects of airborne particulate matter in the Los Angeles Basin.

The U.S. EPA Particulate Matter (PM) Super Sites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods.

NARSTO, which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.