Project title: Indoor/Outdoor Particulate Matter Composition in Rural Yunnan Province, China
Completed in: 2015 | Faculty advisor: Edmund Y. W. Seto
Background: Exposure to high concentrations of fine particulate matter air pollution, with mean diameter of 2.5 micrometers or less (PM2.5), is associated with a range of adverse health effects from birth outcomes to lung cancer. The source (composition) and concentration of the PM2.5 influence the prevalence and severity of these health effects. Exposure to PM2.5 is a function of both the background pollution in a community, and the activities of the individual. In rural China biomass and coal are commonly used for cooking and heating. The incomplete combustion of these fuels raise the concentration of PM2.5, and emit other potentially harmful gaseous byproducts. In Xuanwei, an area of rural Quijing Prefecture in northern Yunnan Province, China, rates of lung cancer are several times higher than the national average. Since the area is not known to be unique in its fuel use and exposure to PM2.5, more research is needed to elucidate the relationship between exposures to air pollution and health outcomes. The composition of the PM2.5 air pollution both within and outside of households in this area may improve understanding of the sources of air pollution and the levels to which individuals may be exposed.
Objective: The objective of this pilot study was to assess the indoor and outdoor PM2.5 concentration and composition of nine residences in rural Yunan province, China.
Methods: Concurrent 12 and 24-hour indoor and outdoor PM2.5 gravimetric samples were collected on Teflon filters in three villages in rural Yunnan province, China in July 2014. Three households in each the villages were sampled. The filters were analyzed for mass concentration, metals and particle bound polycyclic aromatic hydrocarbons (PAHs).
Results: Analysis is ongoing, but preliminary results show a 100 fold difference in concentrations amongst the indoor samples from 23 to 2263 µm/m3, indicating a marked difference in potential exposure to fine particle air pollution. Outdoor concentrations were less variable with a range from 16 to 25µm/m3. Quantifiable results for several PAHs, including 1-nitropyrene and levoglucosan, and metals including lead, arsenic, and bromium was found. These preliminary results suggest that exposures to high concentrations of fine particulate air pollution is still occurring in this area of rural China. Further, the composition of this air pollution may contain harmful constituents that are exacerbating the adverse health outcomes. Additional studies are needed to adequately assess this relationship.URI