AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Source Impacts on Reactive Oxygen Species Generated by Water-Soluble PM2.5 in Atlanta and Associations with Cardiorespiratory Effects
JOSEPHINE BATES, Rodney J. Weber, Joseph Abrams, Vishal Verma, Ting Fang, Mitchel Klein, Matthew Strickland, Stefanie Ebelt Sarnat, Howard Chang, James Mulholland, Paige Tolbert, Armistead G. Russell, Georgia Institute of Technology
Abstract Number: 182 Working Group: Health Related Aerosols
Abstract The catalytic generation of reactive oxygen species (ROS) by atmospheric aerosols may induce oxidative stress in the body and is a suspected mechanism of particle toxicity. A dithiothreitol (DTT) assay was used to measure ROS generation potential of ambient water-soluble PM$_(2.5) in Atlanta during June 2012 - June 2013 alongside a comprehensive suite of speciated PM$_(2.5) measurements. PM$_(2.5) source impacts, estimated using the Chemical Mass Balance method with ensemble-averaged source impact profiles, were related to DTT activity using a linear regression model that was further used to develop a time series of daily DTT activity over a ten year period for use in an epidemiologic study of acute health effects. Light-duty gasoline vehicles exhibited the highest intrinsic DTT activity, followed by biomass burning and heavy-duty diesel vehicles (0.11, 0.069, and 0.052 nmol min$^(-1) μg$^(-1)$_(source), respectively). Biomass burning contributed the largest fraction to total DTT activity, followed by gasoline and diesel vehicles (45%, 20% and 14%, respectively). High day-to-day correlations between DTT activity and gasoline vehicle and biomass burning impacts (R = 0.54 and R = 0.61, respectively) support these results. Epidemiologic analyses found significant associations between estimated DTT activity and hospital visits related to congestive heart failure and asthma/wheezing attacks in the 5-county Atlanta area. Estimated DTT activity was the only pollutant measure out of several pollutants (PM$_(2.5), O$_3, elemental carbon, organic carbon) that exhibited a significant link to congestive heart failure. In two-pollutant models, DTT activity was significantly associated with asthma/wheeze and congestive heart failure while PM$_(2.5) was not, even though DTT activity was likely not estimated as well as PM$_(2.5) was measured. These results support the hypothesis that PM$_(2.5) health effects are, in part, due to oxidative stress and suggest that DTT activity may be a better indicator of some aerosol-related health effects than PM$_(2.5) mass.