Atmospheric fine particulate pollutants in Shenyang city, Liaoning province: 2016 – 2017

Objectiv To analyze the characteristics of atmospheric fine particulate pollutants in Shenyang city of Liaoning province and to provide a reference for developing and implementing long-term effective measures for fog and haze control.

Methods Twenty-four hours continuous sampling was conducted to collect atmospheric particulate matter≤2.5 μm in aerodynamic diameter (PM2.5) at two representative sampling points consecutively for 7 days monthly (from 10th to 16th in a month) in Shenyang city of Liaoning province from September 2016 to December 2017. Four categories of 33 pollutants in PM2.5 samples (including 12 heavy metals, 16 polycyclic aromatic hydrocarbons PAHs, and 4 water-soluble ions) were detected at Department of Physical and Chemical Detection of Liaoning Provincial Center for Disease Control and Prevention.

Results The average daily mass concentration of PM2.5 during the 16-month period in the city was 62.4 μg/m³ and was under the Ambient Air Quality Standard of China (75 μg/m³); but the PM2.5 daily average concentration in the winter season was 99.8 μg/m³ and was above the national standard. The rank order for the average concentration of 12 heavy metals in the PM2.5 samples from high to low was aluminum, lead, manganese, chromium, arsenic, antimony, selenium, nickel, cadmium, thallium, mercury, and beryllium; among the metals, the concentration of arsenic was 5.96 ng/m³ and was close to the reference limit of the Ambient Air Quality Standard of China (6.00 ng/m³). The average total concentration of 16 PAHs in PM2.5 samples was the highest in winter season, followed by that in spring, autumn, and summer seasons; among the 16 PAHs, annual concentration of benzoapyrene was 3.58 ng/m³ and was higher than the reference limit concentration of the Ambient Air Quality Standard of China (1.0 ng/m³). Among the four water-soluble ions, daily average concentration of SO₄^2- was the highest, followed by that of NO₃^-, NH₄⁺ , and Cl^-.

Conclusion The concentration of atmospheric fine particulate pollutants is higher in winter season and some of the pollutants may result in carcinogenic risk in Shenyang city of Liaoning province.