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Ron Williams1, Alan Vette1, Carry Croghan1, Paul Jones1, Dennis Williams2 Charles Rodes3, Jonathan Thornburg3
1U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
2Alion Science and Technology, Research Triangle Park, NC, 27711, USA
3RTI International, Research Triangle Park, NC, 27709, USA

Diffusion monitors were used in the Detroit Exposure and Aerosol Research Study (DEARS) to collect approximately 6000 total nitrogen dioxide, sulfur dioxide and ozone samples as daily 24-hr integrated measurements. Monitoring took place from July 2004 through March 2007 and was associated with summer and winter seasons linked to over 120 different households. Monitoring was conducted as personal, residential outdoor or community-based. One purpose of these measurements was to determine the respective relationships between various co-pollutants, including particulate matter (PM). Comparisons from the first two years of the study will be reported. The passive monitors were an efficient means for collecting data. Collection rates above the limit of detection reached as high as 95% for some samplers (nitrogen dioxide-summer 2005). Data from the summers of 2004 and 2005 as well as the winters of 2005 and 2006 were combined to form one winter versus summer dataset. Personal and community concentrations of sulfur dioxide were typically well below 3 ppb regardless of season. Data indicate that while median indoor air exchange rates were two-fold higher in the summer (0.7 to 1.4 ach), air exchange was not observed to be strongly correlated (r < 0.31) with personal exposures to any gaseous co-pollutant during any season. Community measures of summertime PM2.5 were most strongly correlated with collocated measures of ozone (r = 0.63). Additional comparisons between and among the co-pollutants will be presented.

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

DEARS Home | Human Exposure & Atmospheric Sciences | Exposure Research


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