Quantitative relationship between visibility and mass concentration of PM2.5 in Beijing

• Published in: Journal of environmental sciences (China) Vol. 18; no. 3; pp. 475 - 481
• Main Authors: Wang, Jing-Li, Zhang, Yuan-Hang, Shao, Min, Liu, Xu-Lin, Zeng, Li-Min, Cheng, Cong-Lan, Xu, Xiao-Feng
• Format: Journal Article
• Language: English
• Published: Netherlands Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089, China%State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, China%Beijing Meteorological Information and Network Center, Beijing 100089, China 2006
• Subjects: Air Pollution - analysis; China; Cities; Environmental Monitoring - statistics & numerical data; Humidity; Particle Size; Seasons; Temperature; 大气污染; 气溶胶; 空气污染; 能见度; China; USA; China, People's Rep., Beijing; atmospheric urban aerosol; air pollution; meteorological factor; visibility; PM2.5
• DOI: 10.3321/j.issn:1001-0742.2006.03.011
• ISSN: 1001-0742

The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U,S, national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles （PM2.5） cause atmospheric visibility deterioration through light extinction, The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different： power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.