Seasonal distributions and possible sources of low molecular weight organic acids in PM2.5 from a typical mining city after decade green mining developing in Southeastern Hubei, Central China

Low molecular weight (LMW) organic compounds are prevalent in the atmospheric aerosols. Human activities and natural sources could significantly influence aerosol compositions and concentrations, particularly in a typical mining and metallurgy city. In this study, we measured dicarboxylic acids, ω-oxocarboxylic acids, pyruvic acid, α-dicarbonyls, and fatty acids in PM2.5 from Huangshi, China throughout one year. The results indicated that oxalic acid and glyoxylic acid were the most abundant dicarboxylic acid and ω-oxocarboxylic acid, respectively, across all seasons. Following nearly a decade of environmentally conscious economic development in Huangshi, it is observed that organic compounds primarily accumulated in PM2.5 due to the combustion of fossil fuels for mining-related activities and biogenic emissions. Furthermore, anthropogenic activities, including emissions related to traffic, biomass burning, and plastic incineration, significantly influence the composition of organic aerosols. Natural processes, such as atmospheric oxidation during long-distance transport, predominantly from North China, Mongolia, Russia, and Kazakhstan, also play a substantial role. The findings underscore the transitioning energy structures, modes of transport, and oxidation processes during long-distance transport have already begun to influence the composition of LMW organic compounds. The insights gained from this study offer valuable information for researchers and governmental authorities to understand the molecular composition and potential sources of LMW organic acids in the context of green mining development. This knowledge can aid in the formulation of targeted policies for the prevention and control of carbonaceous pollution in similar mining regions globally.