Association between heating seasons and criteria air pollutants in three provincial capitals in northern China: Spatiotemporal variation and sources contribution

摘要

Spatiotemporal variations of SO2, CO, NO2, O-3, PM2.5, and PM10 concentrations and their associated sources in three provincial capitals of northern China from 2014 to 2015 were examined to reveal the association between heating seasons and criteria air pollutants. Air pollutant concentrations during the heating season were significantly higher than those during the non-heating season, with the exception of O-3. Moreover, the heating season with and without dust storm events was divided into aerosol season and windstorm season respectively. During aerosol season, fossil fuel-based industry and motor vehicle emissions respectively account for a major contribution to particulate matters and gaseous pollutants, and the Chinese Ambient Air Quality Standard (CAAQS) attaining rates of these pollutants exhibited the following order: PM2.5 PM10 NO2 CO SO2 O-3. During windstorm season, concentrations of particulate matter became increasingly pronounced while those of gaseous pollutants decreased, and the major contribution of particulate matters and gaseous pollutants migrated to dust storms and fossil fuel-based industry discharges respectively. The CAAQS attaining rates of air pollutants in this season displayed the following order: PM10 PM2.5 NO2 CO O-3 SO2. The attaining rates of gaseous pollutants during windstorm season improved due to the ambient clearing by wind, which followed the order: NO2 CO SO2 O-3. The findings of this study are helpful in understanding the influence of anthropogenic and natural activities during heating season, which may improve the effectiveness of tackling air pollution in a broader way.