Source apportionment of NMVOCs in the Kathmandu Valley during the SusKat-ABC international field campaign using positive matrix factorization

A study using positive matrix factorization identified eight major sources of non-methane volatile organic compounds (NMVOCs) in the Kathmandu Valley, with unresolved industrial emissions and traffic being the largest contributors. Notably, biomass co-fired brick kilns significantly elevated concentrations of health-relevant NMVOCs like benzene. Biogenic emissions dominated daytime ozone production potential, even in winter, while secondary organic aerosol (SOA) production was equally influenced by brick kilns and traffic. The research also found that existing emission inventories underestimate traffic contributions and omit brick kiln emissions entirely, highlighting gaps in current models. This quantitative source apportionment provides critical insights for refining NMVOC emission inventories and guiding mitigation strategies in the Kathmandu Valley.

Sarkar, C., Sinha, V., Sinha, B., Panday, A. K., Rupakheti, M., & Lawrence, M. G. (2017). Source apportionment of NMVOCs in the Kathmandu Valley during the SusKat-ABC international field campaign using positive matrix factorization. Atmospheric Chemistry and Physics, 17(13), 8129–8156. https://doi.org/10.5194/acp-17-8129-2017