Environmental Measurement and Monitoring: Projects

Chemical Speciation of PM2.5 Filter Samples

Client

US EPA Office of Air Quality Planning and Standards (OAQPS)

Description

We are the prime contractor for EPA's PM2.5 Chemical Speciation Network, a nationwide network for monitoring fine particulate matter in the atmosphere. We assist state and local agencies by providing filter media and analytical support for the analysis of sampler filters for

Mass
Elemental concentrations (sodium through lead)
Organic and elemental carbon
Cations (ammonium, sodium, potassium)
Anions (sulfate and nitrate)
Semi-volatile organics

In early 2003, we provided laboratory support for more than 230 PM2.5 chemical speciation samplers at sites across the United States, including Hawaii and Alaska, and in Puerto Rico. We prepared sampling media, shipped them to field sites where the samples were collected on specified days, and collected them for chemical analysis and reporting of results.

Our laboratories analyze 1800-2000 samples per month for EPA's PM2.5 Chemical Speciation Laboratory Program alone. We combine the results of six chemical analyses with field sampling data to report ambient concentrations of 58 chemical species that may be found in PM2.5. We subject data to validation and flag records as necessary and make reports available to state and local agencies and to EPA on a secure website. State and local agencies review their data and send changes in validation status to RTI. We upload the validated data into EPA's Aerometric Information Retrieval System (AIRS).

To date, we had collected, analyzed, and reported on well over 60,000 PM2.5 samples under this contract.