Prioritizing Urban Emission Reductions to Mitigate Pollution and Health Effects of Ozone and Nitrogen Dioxide in China

Abstract Despite significant reductions in fine particulate matter (PM 2.5 ) concentrations in China due to air pollution control measures, ozone (O 3 ) pollution has worsened in recent years, with pronounced regional disparities in long‐term exposure to O 3 and NO 2 . Assessing these disparities in exposure to gaseous pollutants and the resulting unequal health risks between urban and rural regions has become increasingly essential. The contributions of various anthropogenic emissions to O 3 and NO 2 were quantified using a source‐oriented version of the Community Multiscale Air Quality (CMAQ) model, combined with population and GDP data sets. From 2010 to 2019, NOx and VOC emissions from non‐urban areas decreased by 14% and 25%, respectively, whereas urban anthropogenic activities caused a 10% increase in NOx emissions and a 22% rise in VOC emissions. The simulations indicated that background levels constituted the majority of maximum daily 8‐hr average O 3 (MDA8 O 3 ), contributing 83% in 2010 and 75% in 2019. Non‐urban anthropogenic activities were the primary sources of NO 2 , accounting for 64% in 2010 and 57% in 2019. The proportion of O 3 and NO 2 from urban anthropogenic emissions in the total concentration continuously increased between 2010 and 2019. Although overall O 3 ‐related premature mortality increased by 51% and NO 2 ‐related premature mortality decreased by 3% during this period, the number of premature mortalities related to O 3 and NO 2 from urban anthropogenic activities rose by 133% and 15% respectively. We underscore the critical need to prioritize the reduction of urban anthropogenic emissions to effectively mitigate O 3 and NO 2 pollution in China.