气候变化领域集成服务门户

Accurate characterization of the chemical composition of particulate matter (PM) is essential for improved understanding of source attribution and resultant health impacts. To explore this, we conducted ambient monitoring of a suite of 15 combustion-related organic species in temporally resolved PM2.5 samples during an ongoing animal exposure study in a near source environment in Detroit, MI. All of the 15 species detected were above the method detection limit in 8 h samples. This study focused on two molecular classes: polycyclic aromatic hydrocarbons (PAHs) and hopanes measured in samples. Of the 12 PAHs studied, benzo[b]fluoranthene (169 pg m(-3)), benzo[g,h,i]perylene (124 pg m(-3)), and benzo[e]pyrene (118 pg m(-3)) exhibited the three highest mean concentrations while 17 alpha(H),21 beta(H)-hopane (189 pg m(-3)) and 17 alpha(H),21 beta(H)-30-norhopane (145 pg m(-3)) had the highest mean concentrations of the three hopanes analyzed in samples. Ratios of individual compound concentrations to total compound concentrations (a15 compounds) showed the greatest daily variation for 17 alpha(H),21 beta(H)-hopane (11-28%) and 17 alpha(H),21 beta(H)-30-norhopane (8-20%). Diagnostic PAH concentration ratios ([IP]/[IP + BP] (range 0.30-0.45), [BaP]/[BaP + BeP] (range 0.26-0.44), [BaP]/[BP] (range 0.41-0.82), [Bb]/[Bk] (range 2.07-2.66)) in samples reflected impacts from a mixture of combustion sources consistent with greater prevalence of petroleum combustion source emissions (gasoline, diesel, kerosene, and crude oil) compared to coal or wood combustion emissions impacts at this urban site. Results from this study demonstrate that short-duration sampling for organic speciation provides temporally relevant exposure information.