Characterization of fine particles in urban areas of Shanghai

Abstract

Abstract Based on five consecutive years of measured data from January 2008 to December 2012 at representative observation sites in Shanghai, we analyzed the fine particle mass concentrations and their variation characteristics. The main conclusions drawn are as follows: the annual average mass concentrations of PM (including PM1, PM2.5 and PM10) in Shanghai city exhibited a decreasing trend. PM1 decreased from 46.7 ± 34.7 to 32.1 ± 25.4 µg/m3 (annual mean ± standard deviation), PM2.5 decreased from 53.2 ± 37.4 to 36.7 ± 26.9 µg/m3 and PM10 decreased from 70.2 ± 46.7 to 49.2 ± 34.7 µg/m3. In terms of the 5-year average mass concentrations, PM1, PM1–2.5 (particulate matter with a particle size dp of 1–2.5 µm) and PM2.5–10 (particulate matter with a dp of 2.5–10 µm) accounted for about 61.1%, 11.3% and 27.6% of PM10, respectively. The seasonal average mass concentrations of PM1, PM2.5 and PM10 from 2008 to 2012 were highest in winter, followed by autumn and lowest in summer. The average mass concentration of PM1–10 (particulate matter with a dp of 1–10 µm) was 2.2, 1.7 and 1.4 times higher in spring than in summer, autumn and winter, respectively. The proportion of PM1–10 to PM10 was 48.9%, 37.0%, 35.9% and 33.3% in spring, summer, autumn and winter. In spring, Shanghai was affected by sand and dust aerosols from northern China and more severely by PM1–10 from Zhejiang, Jiangxi and Fujian; in autumn and winter, Shanghai was more influenced by PM1–10 from Henan, Hubei and Anhui.