title: Control of PM2.5 in Guangzhou during the 16th Asian Games period: implication for hazy weather prevention.
abstract: To evaluate the effectiveness of the integrated control measures for reducing PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) and hazy weather, day- and night-time PM2.5 samples were collected at an urban site in Guangzhou during the 16th Asian Games period in November 2010. PM2.5 samples were subject to chemical analysis for major water-soluble ions, organic carbon (OC), element carbon (EC), and biomass burning tracers-anhydrosugar levoglucosan (LG). In addition, aerosol scattering coefficient (bsp) at dry condition and aerosol absorption coefficient (bap) and visibility at ambient condition were measured. The seven major control measures were effective for reducing PM2.5 mass concentration and improving visibility during the Asian Games period. All monitored air pollutants except PM2.5 satisfied the National Ambient Air Quality Standards (NAAQS). However, daily PM2.5 concentrations still exceeded the NAAQS on 47% of the days and hazy weather also occurred on 80% of the days during this period. One factor causing the high frequency of hazy weather occurrence was the increased relative humidity during the Asian Games period. To avoid hazy weather occurrence, new PM2.5 standard was recommended based on visibility calculations using three available aerosol hygroscopic curves previously obtained for this city. The recommended PM2.5 standard was 63 μgm(-3) under dry condition and lower than 42 μg m(-3) under humid condition (RH ≥ 70%). These recommended value s were much stricter than the NAAQS value of 75 μg m(-3). To reach the new standard, more rigorous control measures for coal industries should be established in the Pearl River Delta (PRD) region.
authors.affiliation: South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, China; Key Laboratory of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China. Electronic address: taojun@scies.org.
authors.forename: Jun
authors.initials: J
authors.lastname: Tao
authors.affiliation: Air Quality Research Division, Science Technology Branch, Environment Canada, Toronto, Canada.
authors.forename: Leiming
authors.initials: L
authors.lastname: Zhang
authors.affiliation: South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, China.
authors.forename: Zhisheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Huang
authors.affiliation: RCE-TEA, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Wu
authors.affiliation: RCE-TEA, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Renjian
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China. Electronic address: cao@loess.llqg.ac.cn.
authors.forename: Junji
authors.initials: J
authors.lastname: Cao
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing, China.
authors.forename: Yuanhang
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control* / Q000706:statistics & numerical data; D002681:China; D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis*; D014887:Weather
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Air quality; Hygroscopic growth; Pollution control; Visibility