AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Do 16 PAHs Adequately Represent Atmospheric PAH Toxicity?
VERA SAMBUROVA, Barbara Zielinska, Eric Fujita, Andrey Khlystov, Desert Research Institute
Abstract Number: 596 Working Group: Health Related Aerosols
Abstract Atmospheric polycyclic aromatic hydrocarbons (PAHs) are of major concern in all environmental compartments due to their mutagenic and carcinogenic properties. The most common carcinogenic effect of PAHs on human cells is DNA damage through the formation of adducts in a number of organs, including liver, kidney, lungs, etc. For this reason, the role of atmospheric PAHs in carcinogenic potency of atmospheric emissions has to be carefully estimated.
PAHs are mainly formed during natural and anthropogenic combustion processes of fuels like wood, coal, peat, oil, fossil fuels, waste, crop/agricultural waste, animal dung, etc. In the present study, concentrations of 113 gas- and particle phase PAHs measured during various ambient (mostly urban locations) and source studies (including vehicular, biomass burning, etc. emissions) were used to estimate relative carcinogenic risks of gaseous and particulate PAHs based on their toxicity equivalency factors.
Among the 16 EPA PAHs, particle phase PAHs were found to have significantly larger total estimated toxicity. However, by measuring only particle phase PAHs, a significant part of aerosol toxicity could be missed. Further, when emitted into the atmosphere, gas-phase PAHs may be transformed into products with stronger carcinogenic and mutagenic properties (i.e., oxo- and nitro-PAHs) via photo-chemical reactions. Some PAH species, which are not included in the list of 16 EPA PAHs, are very abundant. This raises a question whether the 16 EPA PAHs adequately represent the total PAH toxicity. Carcinogenic properties of most of the analyzed 113 PAHs are still unknown and need to be determined for accurate determination of aerosol carcinogenic potency.