Long-term spatiotemporal variations of atmospheric sulfur, nitrogen and particle pollutants in Chongqing, southwest China: implication of industrial transfer.

Industrial transfer has swept through in China. However, there is still a knowledge gap about its environmental effects. In this study, industrial transfer status was assessed and evaluated by industrial ratios (%; the gross product contributions of the secondary industry to the whole industry) and the impact of such transfer on atmospheric environment (SO2, NO2, PM10 (particles with aerodynamic diameter less than 10 μm), precipitations of SO42-, NO3-, and NH4+) in the 38 districts and counties in Chongqing was analyzed and discussed for the period of 2006-2015. Results showed that industries were transferred obviously from the main urban region (MUR) into the 1-h economic region (OHER). Atmospheric sulfur and PM10 were efficiently put in control, but atmospheric nitrogen (NO2; precipitations of NO3- and NH4+) was increasing and posted a potential threat to air quality especially during 2011-2015. Correlations showed that industrial ratios had significantly positive relationships with concentrations of ambient SO2 and PM10 in the MUR and ambient NO2 in the OHER (p < 0.05) while a remarkably negative one with concentrations of ambient SO2 in the OHER (p < 0.05) during 2006-2015, implying that industrial transfer could be effective in transferring sulfur pollution but not as efficient in transferring atmospheric nitrogen and PM10 pollutions as SO2 between in the MUR and OHER. More measures should be taken to reduce nitrogen and PM10 emission and a regional monitoring network of ambient NH3 is in urgent need.