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Differential toxicity of PM2.5 components and modified health effects modeling: A case study in Nepal
Open Access Thesis
Master of Science (M.S.)
Year Degree Awarded
Month Degree Awarded
During the latter part of the 20th century, a transition away from coal as a major energy source in developed countries was accompanied by a notable decrease in air pollution-related deaths in those countries. Currently the same phenomenon is being observed in developing nations like China and India. However, many areas that do still rely on coal for their energy production or industrial needs also reflect a gap in research on the effects of those specific processes on local populations. Located in Nepal at the foot of the Himalayan Plateau, Kathmandu represents one such location. The local economy of Kathmandu and the surrounding area relies heavily on the production of bricks using coal-fired kilns, which produce large amounts of particulate matter. This particulate matter contains a characteristic mix of metals. This unique fingerprint can be used to identify and track kiln emissions in ambient samples. We collected hourly samples of ambient metal concentrations over a period of three months at the start of 2019. We then used these data to perform positive matrix factorization (PMF) to identify several factors contributing to the ambient air pollution of the sampled area, each representing a source type. The PMF output included the chemical ‘fingerprint’ of each factor as well as hourly variation of each factor. We were able to isolate the fraction of PM2.5 contributed by coal and estimate the health effects attributable to this fraction using a modified risk ratio of 1.05 to reflect the higher toxicity of coal emissions. We found that the current estimates of health impacts in Nepal underestimate the true impact of coal by 416 deaths per year.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Brownholtz, Jeremy, "Differential toxicity of PM2.5 components and modified health effects modeling: A case study in Nepal" (2023). Masters Theses. 1265.