Seasonal Variation of PM2.5 Concentration and Correlations with Meteorological Factors inDifferent Urban Green Spaces

Determinations were implemented on PM2.5 concentration and meteorological factors (temperature, relative humidity and wind speed) inthe four different urban green spaces in Lin’an district, Zhejiang province from March 2017 to February 2018. The results showed that the seasonalvariations of PM2.5 concentration in different green spaces were followed by winter > autumn > spring > summer. PM2.5 concentration in the spring,summer and winter was ordered by commercial area green space > residential district green space > public service facilities green space > squaregreen space, and in the autumn was by commercial area green space > residential district green space > square green space > public service facilitiesgreen space. The daily variation of PM2.5 concentration in above-mentioned green spaces was greatly affected by the flow of people and trafficemissions, which was particularly pronounced during the off-hours peak (17:00-20:00). There was a extremely significant negative correlation ofPM2.5 concentration in green spaces with temperature (P<0.01), but significant positive correlation with relative humidity (P<0.05), and correlationwith wind speed (P<0.05).