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PERSONAL EXPOSURES TO POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH THE NHEXAS PILOT
Citation:
Williams, R W., B. Ryan, S C. Hern, L Kildosher, C. L. Witherspoon, AND K Hammerstrom. PERSONAL EXPOSURES TO POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH THE NHEXAS PILOT. Presented at 11th Annual Meeting of the International Society of Exposure Analysis, Charleston, SC, November 4-8, 2001.
Impact/Purpose:
The overall objectives of this task are to
1) conduct analyses of the NHEXAS data for description of data quality and aggregate exposures;
2) review, summarize, and organize the NHEXAS questionnaire and analytical results databases, and
3) collect and record the experiences and recommendations of the study investigators and staff regarding key lessons which were learned in conducting these studies.
Description:
Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD. Twenty-four hour PM10 sample collections (~5.7 m3) were performed using personal environmental monitors (PEMs-MSP Inc.) and Teflon filter media. Monitoring was performed for 47 households and 6 sampling cycles (seasons) during 1995-1996. The volunteers wore the sampling apparatus continuously except during periods of sleep, bathing or clothing changes. Participants were selected from rural, urban and suburban areas. Over 250 personal air samples were returned to the laboratory for analysis. Filter samples were extracted with dichoromethane and prepared for time-programmable fluorescence-high performance liquid chromatography and PAH quantification. A total of 9 PAHs were speciated (e.g., chrysene, benzo(a)pyrene) as well as two aggregate groupings (total PAHs, total carcinogenic PAH). Individual PAH limits of detection ranged from 0.1 to 0.01 ng/m3. Quality control from spiked filter samples indicated excellent recovery of the PAHs, typically exceeding 80% with minimal resulting artifacts (<1.0 pg/ul extract). Results indicate that ~50 % of the selected samples had detectable concentrations for 3-5 of the individual PAHs. Noted differences were observed between exposure concentrations from individuals living in rural areas as compared to urban/suburban environments. Benz(a)anthracene, benz(b)fluoranthene, benz(a)pyrene, and indeno(cd)pyrene were the dominant targeted PAHs in the non-rural settings. Personal exposures from the more populated environments were often one order of magnitude higher in total PAH concentrations (sometimes exceeding 10 ng/m3). Carcinogenic PAHs routinely contributed over 75% to the total PAH mass concentration.
This work has been funded wholly by the United States Environmental Protection Agency under cooperative agreement # CR-822038 to Harvard School of Public Health, and contract 68-D5-0049 to ManTech Environmental Technology. It has been subjected to Agency review and approved for publication.