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UTILIZING THE PAKS METHOD FOR MEASURING ACROLEIN AND OTHER ALDEHYDES IN DEARS
Citation:
HERRINGTON, J., J. ZHANG, L. ZHING, D. A. WHITAKER, R. W. WILLIAMS, AND C. RHODES. UTILIZING THE PAKS METHOD FOR MEASURING ACROLEIN AND OTHER ALDEHYDES IN DEARS. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Impact/Purpose:
Six objectives have been defined for this study.
(1) To determine the associations between concentrations measured at central site monitors and outdoor residential, indoor residential and personal exposures for selected air toxics, PM constituents, and PM from specific sources.
(2) To describe the physical and chemical factors that affect the relationship between central site monitors and outdoor residential and indoor residential concentrations, including those that affect ambient source impacts.
(3) To identify the human activity factors that influence personal exposures to selected PM constituents and air toxics.
(4) To improve and evaluate models used to characterize and estimate residential concentrations of and human exposures to selected air toxics, PM constituents, and PM from specific sources.
(5) To investigate and apply source apportionment models to evaluate the relationships for PM from specific sources and to determine the contribution of specific ambient sources to residential concentrations and personal exposures to PM constituents and air toxics.
(6) To determine the associations between ambient concentrations of criteria gases (O3, NO2, and SO2) and personal exposures for these gases as well as personal exposures to air toxics, PM constituents, and PM from specific sources.
Description:
Acrolein is a hazardous air pollutant of high priority due to its high irritation potency and other potential adverse health effects. However, a reliable method is currently unavailable for measuring airborne acrolein at typical environmental levels. In the Detroit Exposure and Aerosol Research Study (DEARS), we employed a newly developed method to measure acrolein and the two most abundant aldehydes: formaldehyde and acetaldehyde. This method involves the collection of the aldehydes using the Passive Aldehydes and Ketones Sampler (PAKS) and the subsequent sample analysis using an HPLC-Fluorescence technique. The PAKS is a diffusion-driven sampler consisting of solid sorbent coated with dansylhydrazine (DNSH) that derivatizes aldehydes into fluorescence-generating compounds. Two versions of the PAKS method have been used in the DEARS so far. The version used during the first sampling season (July - August, 2004) was modified from the originally published PAKS method and had method collection efficiencies of ~100% for all three aldehydes. Results from the samples collected in the first season showed that this version of the method exhibited relatively high laboratory and field blank levels for formaldehyde and acetaldehyde. Thus, this version was further modified to minimize the laboratory and field blank levels. The method used during the second sampling season (February - March, 2005) did not exhibit high blank levels, but had slightly reduced collection efficiency for acrolein (85%). The sensitivity of the final method was demonstrated to be adequate for the 24-hour integrated sampling duration used in the DEARS. Based on the 24-hour sampling duration, the limits of detection (air concentration) were 0.96 (0.78), 0.75 (0.42), and 0.57 (0.25) µg/m3 (ppb) for formaldehyde, acetaldehyde, and acrolein, respectively.
Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.