Using a Pollution-to-Risk Method to Evaluate the Impact of a Cold Front: A Case Study in a Downstream Region in Southeastern China

Cold fronts frequently intrude China in winter, causing air pollution episodes downwind regions. Fine particulate matter (PM2.5) has been used as a major proxy of to examine the impacts cold fronts. Compared particles, gaseous pollutants can cause comparable or even higher levels short-term health risks. In this study, pollution-to-risk model was systematically evaluate on combined risks mixtures, including PM2.5, nitrogen dioxide (NO2), ozone (O3), and sulfur (SO2). Dominant that caused significant mortality during frontal passage December 2019 over Fuzhou, city southeastern China, were then examined. Under northerly airflows, belt propagated southwards. two peaks existed passage. At first peak, convergence stagnant zone rapidly accumulated local pollutants. The dominant risk identified NO2 both which contributed 45% total risk. second advection transported amount secondary from upwind Although PM2.5 pollutant at still accounted for 34% Our analyses underscore passages winter. results generated study will help guide environmental policy makers forming improving control strategies episodes.