Spatiotemporal dynamics of atmospheric PM2.5 and PM10 and its influencing factors in Nanchang, China

Abstract

PM2.5 and PM10 have become the primary pollutants of most cities in China. Atmospheric PM2.5 and PM10 mass concentrations, meteorological factors, traffic flow from 2013 to 2015 in Nanchang were analyzed. Spatiotemporal dynamic pattern of atmospheric particulate matter pollution and the effect of weather and traffic on particle concentration change were discussed in this paper. The results showed that PM2.5(70.92 μg·m-3 in 2013 > 53.70 μg·m-3 in 2014 ＞ 43.65 μg·m-3 in 2015) and PM10(119.72 μg·m-3 in 2013 ＞ 86.11 μg·m-3 in 2014 ＞ 73.32 μg·m-3 in 2015) concentrations decreased gradually from 2013 to 2015. In addition, low concentrations of PM2.5 and PM10 in summer (average PM2.5 concentration 36.74 μg·m-3, average PM10 concentration 69.20 μg·m-3) but high concentrations in winter (average PM2.5 concentration 74.29 μg·m-3, average PM10 concentration 111.64 μg·m-3) were observed. Moreover, PM2.5 and PM10 concentrations changed with the urban-rural gradient, decreasing from the city center to suburb. The ratio of PM2.5/PM10(0.595 ＞ 0.584 ＞ 0.557) decreased year by year from 2013 to 2015 and was higher in the city center area than in the edge of city. PM2.5 and PM10 concentrations were affected by various meteorological factors and significantly related to air pressure, temperature, relative humidity, wind speed, precipitation and sunshine time. The influence of meteorological factors differed on PM2.5 and PM10 concentrations. Traffic flow significantly increased the surrounding PM2.5 concentration, but not PM10 concentration.