AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Chemical Characterization and Redox Activity of Roadside Trash Burning Particulate Matter (PM) Emissions in Bangalore, India
VREELAND HEIDI, Michael Bergin, Akihiro Fushimi, Armistead G. Russell, Grishma Jain, Karthik Sethuraman, James Schauer, Ana Villalobos, S.N. Tripathi, Julian Marshall, Duke University
Abstract Number: 400 Working Group: Urban Aerosols
Abstract Open waste burning is a prevalent yet under-examined source of particulate matter (PM) emissions. In order to make initial assessments of PM characteristics associated with the common practice of roadside trash burning, emissions from smoldering roadside trash piles (n=24) as well as samples from ambient air (n=6) were collected in Bangalore, India for fine particulate matter (particles that have diameters less than 2.5 μm). Samples were analyzed for organic and elemental carbon (OC/EC), water- and methanol-soluble brown carbon, and redox activity (measured according to the DTT assay); some samples (n=8) were further assessed for biological redox activity (according to the macrophage assay) and were also analyzed by GC/MS for organics (PAHs, levoglucosan, alkanes, di-acids, and alkanoic acids). Results show that trash-burning emissions are highly variable in chemical composition and redox activity, and significant differences are observed between the trash-burning and ambient samples. Trash-burning OC/EC ratios range from 0.80 to 1500, while ambient OC/EC ratios are observed at 5.44 ± 1.81. Roadside trash-burning emissions do not appear to significantly contribute to ambient fine particulate mass. However, people passing by these roadside burn piles are exposed to concentrated PM masses with high per-volume redox activity, suggesting that exposure could be dominated by short bursts of highly variable burning. Interestingly, on a per-mass basis, results suggest that trash-burning emissions are innately less redox-active than ambient air (13.4 ± 14.8 pmol/min/μg for trash burning, and 107.1 ± 25.0 n pmol/min/μg for ambient), which may indicate that toxicity increases over time as aerosols in the atmosphere are aged and processed.