About the Health Effects Web Site

Welcome to the Health Effects Study Web Site. This web site provides access to (1) Information on EPA's Speciation Trends Network and supplemental sites, (2) ambient concentration data on particulate matter (PM2.5) and speciation, (3) associated gas-phase concentration data, and (4) associated meteorology data.

The website and database system is owned and operated by AER, Inc. and is copyrighted by AER. The Air Quality System database (from which PM, gas and meteorology data are obtained; click here for details) is provided the U.S. Environmental Protection Agency. Other sources of data include the National Climatic Data Center's Hourly Observations, EPA's National Emissions Inventory (NEI), and the Census Bureau. These database contents are in the public domain are not copyrighted by AER. The Funding for the development of the website and database was provided by the Health Effects Institute (HEI, website) .