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Amines affect particle formation, aerosol acidity, nitrogen cycle, and climate change. However, little is known about the temporal and spatial differences in the composition, source, and formation process of amines in fine particulate matter (PM2.5) in different regions of China. Seven amines (amine salts) were investigated in PM2.5 collected in the Yangtze River Delta (YRD, Shanghai and Nanjing), Pearl River Delta (PRD, Guangzhou), northern China (Xi'an and Haerbin), and background (Puding) areas in winter 2017–2018. Methylamine was the dominant amine species at the YRD, northern China, and background sites, while diethylamine dominated at the PRD site; moreover, the mass concentration and fraction of diethylamine were the lowest at the background site. These results could be attributed to changes in sources and atmospheric processes. Further, coal combustion and biomass burning were found to be important contributors of amines in northern cities in winter. The contribution of biomass and coal combustion to amines was weakened in other urban sites. In contrast, the amine abundance at the background site was largely controlled by biogenic sources. Acid‐base chemistry and displacement mechanism were tightly associated with the formation of amine salts at all sites. In particular, the atmospheric degradation of amines by hydroxyl radical (•OH) was significant at the Nanjing, Guangzhou, Xi'an, and Haerbin sites. The insignificant photochemical degradation of amines at the Shanghai and background sites can be explained by differentiated amine sources, meteorological conditions, and •OH levels. Overall, our findings deepen the understanding of the origins and atmospheric processes of amines. Plain Language Summary: Concentrations, compositions, potential sources, and major atmospheric processes of amines in winter PM2.5 in different regions of China were systematically investigated for the first time. The concentrations and compositions of amines in PM2.5 showed significant spatial differences, with the dominance of diethylamine at the Guangzhou site and the dominance of methylamine at other sites (Nanjing, Shanghai, Xi'an, Haerbin, and background sites). The influence of coal combustion associated with heating and industry was a typical feature that distinguishes the difference of amine sources between the coastal and northern areas. Moreover, the overall amine abundance at the background site was largely controlled by biogenic sources. Acid‐base chemistry and displacement mechanism were tightly associated with the formation of amine salts in PM2.5 at all sites. The atmospheric processes related to •OH exerted a significant impact on the removal of amines at the Nanjing, Guangzhou, Xi'an, and Haerbin sites. The insignificant photochemical degradation of amines in the Shanghai and background areas was associated with varied amine sources, meteorological conditions, and •OH levels. The overall results improve the current understanding on the temporal and spatial variations in the composition, source, and atmospheric process of amines in China. Key Points: Changes in the source led to large differences in the concentration and composition of amines in winter PM2.5 across regionsAcid‐base chemistry contributed significantly to the formation of amine salts in PM2.5 at all study sitesThe atmospheric degradation of amines by •OH was significant only at the Nanjing, Guangzhou, Xi'an, and Haerbin sites [ABSTRACT FROM AUTHOR]

Studies on the effects of airborne particulates of diameter ≤ 1 µm (PM 1), airborne particulates of diameter ≤ 2.5 µm (PM 2.5) and airborne particulates of diameter ranges from 1 to 2.5 µm (PM 1–2.5) on incidence of hyperuricemia are limited. We aimed to investigate the associations between PM 1 , PM 2.5 , and PM 1–2.5 and hyperuricemia among male traffic officers. We conducted a prospective cohort study of 1460 traffic officers without hyperuricemia in Guangzhou, China from 2009 to 2016. Exposures of PM 1 and PM 2.5 were estimated with a spatiotemporal model. PM 1–2.5 concentrations were calculated by subtracting PM 1 from PM 2.5 concentrations. Cox's proportional hazards regressions models were used to examine the association between PM 1 , PM 2.5 , and PM 1–2.5 and hyperuricemia, adjusted for potential confounders. Associations between PM 1 , PM 2.5, and PM 1–2.5 and serum uric acid (SUA) levels were evaluated with multiple linear regression models. Hazard ratios (HRs) and 95% confidence intervals (CIs) of hyperuricemia associated with 10 μg/m3 increment in PM 1 , PM 2.5 , and PM 1–2.5 were 1.67 (95% CI:1.30–2.36), 1.49 (95% CI: 1.27–1.75), and 2.18 (95% CI: 1.58–3.02), respectively. The SUA concentrations increased by 12.23 μmol/L (95% CI: 5.91–18.56), 6.93 μmol/L (95% CI: 3.02–10.84), and 8.72 μmol/L (95% CI: 0.76–16.68) per 10 μg/m3 increase in PM 1 , PM 2.5 , and PM 1–2.5 , respectively. Stratified analyses indicated the positive associations of PM 2.5 and PM 1–2.5 with SUA levels were stronger in non-smokers, and PM 1 , PM 2.5, and PM 1–2.5 with SUA levels were stronger in non-drinkers. Long-term PM 1 , PM 2.5 , and PM 1–2.5 exposures may increase the risk of hyperuricemia and elevate SUA levels among male traffic officers, especially in non-smokers and non-drinkers. • Evidence on the effects of PM exposure on incidence of hyperuricemia is limited. • PMs were associated with incidence of hyperuricemia and elevated SUA levels. • Non-drinkers and non-smokers are found as sensitive to the adverse effect of PM. [ABSTRACT FROM AUTHOR]