You are here:
COMPARATIVE TOXICITY OF SIZE FRACTIONATED AIRBORNE PARTICULATE MATTER OBTAINED FROM DIFFERENT CITIES IN THE USA.
Citation:
GILMOUR, M. IAN I., J. K. MCGEE, M. J. DANIELS, E. BOYKIN, T. GORDON, AND R. B. DEVLIN. COMPARATIVE TOXICITY OF SIZE FRACTIONATED AIRBORNE PARTICULATE MATTER OBTAINED FROM DIFFERENT CITIES IN THE USA. . Presented at American Thoracic Society Annual Meeting, San Diego, CA, May 19 - 24, 2006.
Description:
Hundreds of epidemiological studies have shown that exposure to ambient particulate matter is associated with dose dependent increases in mortality and morbidity in the exposed population. While most of the early reports focused on PM10, independent studies are now showing that that the effects can occur with ultrafine (UF), fine (FI) and coarse (CO) particles. Despite these observations, it is still not clear what specific components of ambient PM are causing the effects, and whether there are regional differences that may relate to chemical composition. For this reason high volume 3 stage particle impactors with the capacity to collect UF, FI an CO particles were deployed to four different locations in the US (Seattle WA, Lindon UT, Sterling Forest and South Bronx NY), and weekly samples were collected for one month in each place. The particles were extracted, assayed for a number of chemical components and instilled into mouse lungs (female Balb/C) at doses of 25 and 100 micrograms. 18 hrs later animals were euthanized and parameters of injury and inflammation were monitored in the plasma and bronchoalveolar lavage fluid. In general the coarse ambient PM was more toxic than fine and ultrafine PM and elicited a more consistent dose dependency in relation to pulmonary inflammatory markers such as LDH and neutrophils. Of the four locations, the South Bronx coarse fraction was the most toxic sample in both pulmonary and systemic biomarkers with a strong increase in pulmonary inflammatory cells as well as creatine kinase and amino S transferase in the plasma. This effect was associated with total iron in the sample and did not correlate with LPS otal zinc or sulfate content. This bioassay approach is a useful way to compare toxicity of different PM size fractions and to relate toxic effects to specific chemical constituents. (This abstract does not reflect EPA policy).