Size-distribution and driving factors of aerosol oxidative potential in rural kitchen microenvironments of northeastern India.

This study reports size-resolved dithiothreitol (DTT)-based oxidative potential (OP: total and water-soluble) in rural kitchens using liquefied petroleum gas (LPG), firewood (FW), and mixed biomass (MB) fuels in northeastern (NE) India. In comparison to LPG, volume-normalized total OP (OP _total(v) ^DTT ) was enhanced by a factor of ∼5 in biomass-using kitchens (74 ± 35 to 78 ± 42 nmol min ^-1 m ^-3 ); however, mass-normalized total OP (OP _total(m) ^DTT ) was similar between LPG and FW users and higher by a factor of 2 in MB-using kitchens. The water-insoluble OP (OP _{wi(v, m)} ^DTT ) fraction in OP _{total(v, m)} ^DTT was greater than 50% across kitchens. Size distributions across kitchens and OP ^DTT categories ranged from unimodal to trimodal. OP _ws(v) ^DTT was driven by metals as well as organics across size fractions while OP _wi(v) ^DTT was majorly constrained by metals with an increasing importance of organics in fine particles of biomass-using kitchens. Multiple linear regression analysis revealed that Cu and Ba explained 71% of the OP _total(v) ^DTT variability in LPG-using kitchens, while water-soluble organic carbon (WSOC) and Ba were responsible for 44% variability in FW-using kitchens. Finally, the high internal dose of OP _total(v) ^DTT (28-31 nmol min ^-1 m ^-3 ) in biomass-using kitchens established the severity of oxidative stress on the exposed population.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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