Inhalable particles (PM10), with aerodynamic equivalent diameters that are generally 10 micrometers or smaller, are basic pollutants in many areas, especially in northern China, and thus the pollution from PM10 inhalable particulate matter is a growing concern for public health. Independent long-term observations are necessary to evaluate the efficacy of PM10 reduction actions. Variations in the PM10 concentration from 2006 to 2017 at an observation station (NJ) in Beijing were recorded and analyzed. The average value ±1 standard deviation of daily mean PM10 concentrations was 138.8 ± 96.1μg m-3 for 1307 days (accounting for 34.7％of the total days), showing PM10 concentration exceeding the National Ambient Air Quality Standard (NAAQS) 24-h average of 150 μg m-3. Particulate concentration depended upon various meteorological conditions as also observed in this work:at low wind speed (<4 m s-1), the concentrations of PM10 revealed a downward trend with-19μg m-3 per unit of wind speed, but when wind speed rose (>4 m s-1), the values increased by 49 μg m-3 per unit of wind speed. In Beijing, air masses from northwest China, especially from the Gobi Desert and other desert areas, had net contributions to long-range transport of natural dust, enhancing the PM10 concentrations by up to 29％. Overall, PM10 mass concentration showed a significant downward trend with-8.0μg/m3/yr from 2006 to 2017. Although with higher fluctuations in recorded data, similar downward trends derived from the government released data were also found at the nearby districts. The result delivered a proof of efficacy for the reduction actions recently adopted to limit PM10 concentrations in Beijing. Very significant difference of diurnal changes in PM10 concentrations was also found in two periods of 2006-2011 and 2012-2017, which might be due to the different contributions of fugitive dust. Nevertheless, further efforts, especially on controlling fugitive dust, should be planned as the PM10 concentration annual mean value (94μg m-3) in 2017 still exceeded the NAAQS standard. The results showed that there is still a long way to go to reduce PM10 in Beijing.

NAN Xue-jing;LIN Wei-li;HE Xiao-lei;LEI Yong;Andrea MERLONE

Meteorological Observation Centre,China Meteorological Administration,Beijing 100081 China;Key Laboratory of Ecology and Environment in Minority Areas(Minzu University of China),National Ethnic Affairs Commission,Beijing 100081 China;Istituto Nazionale di Ricerca Metrologica,Torino 10135,Italy and Istituto di Scienze Polari,Consiglio Nazionale delle Ricerche,Venezia Mestre 30172 Italy

热带气象学报（英文版）

[1]NAN Xue-jing;LIN Wei-li;HE Xiao-lei;LEI Yong;Andrea MERLONE-.PM10 Observed at a Meteorological Station in Beijing:Historical Trend and Implications)[J].热带气象学报（英文版）,2022(02):207-217

Inhalable,NAAQS

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