You are here:
GAS PARTICLE PARTITIONING OF CHLORDANES IN COUPLED INDOOR/OUTDOOR AIR SAMPLES FROM THREE U.S. CITIES
Citation:
Offenberg, J, Y. Y. Naumova, S. Eisenreich, AND B. Turpin. GAS PARTICLE PARTITIONING OF CHLORDANES IN COUPLED INDOOR/OUTDOOR AIR SAMPLES FROM THREE U.S. CITIES. Presented at Fourth SETAC World Congress, Portland, OR, November 14-18, 2004.
Impact/Purpose:
1. Present the findings of the literature review of the 33 classes of air toxic compounds to OAQPS. The compounds to be investigated under the present task will be based on recommendations by OAQPS.
2. Carry out laboratory investigations to fill in the gaps and reduce uncertainties in the gas phase chemical mechanisms of selected air toxic compounds.
3. Carry out computational chemistry investigations to fill in the gaps and reduce uncertainties in the gas phase chemical mechanisms of selected air toxic compounds compounds.
4. Based on the results of the laboratory and computational chemistry studies, develop improved gas phase chemical mechanisms for selected air toxic compounds that can be used to predict ambient concentrations.
Description:
Concentrations of six Chlordane species (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, oxychlordane and MC5) were measured indoors and outdoors at 157 non-smoking residences in three urban areas during June 1999-May 2000. These measurements were performed on a subset of samples collected within the Relationship of Indoor, Outdoor, and Personal Air study (RIOPA). The objective of the study was to evaluate the hypothesis that outdoor air pollution strongly contributes to indoor air pollution. Forty-eight hour integrated samples were collected from homes in Los Angeles County, CA, Houston, TX, and Elizabeth, NJ. Both particle bound (PM2.5; quartz fiber filter) and vapor phase (PUF adsorbant) chlordane concentrations were separately measured by GC/EI-MS after solvent extraction. The measured partition coefficients of Chlordanes were correlated with the compounds' sub-cooled liquid vapor pressure. Measured partition coefficients varied by two orders of magnitude for any value of vapor pressure. These variations in gas/particle partitioning of Chlordanes are related to the aerosol characteristics and sampling conditions. Multiple linear regression analysis (MLR), which included temperature corrected vapor pressure, fOC and fEC as independent variables, as well as corresponding interaction terms, explains up to 44% of the variability of the partition coefficients. This is higher than the explained variance when vapor pressure is used as a single parameter. The relative importance of each variable for prediction of partition coefficients in both indoor and outdoor air will be discussed. Further comparisons of octanol-air partition coefficient with vapor pressure will also be presented.
Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect Agency policy.