Emission Characteristics and Health Risk Assessment of VOCs in Shandong Province, Eastern China, During Haze Episode

Volatile organic compounds (VOCs) are essential precursors of second organic aerosol (SOA), they have significant impact on air quality and human health. The aim of this study was to characterize VOCs in Shandong Province, Eastern China during haze pollution episode in December 2017 to January 2018, and described their spatial distribution, SOA formation potential, and provided a health risk assessment. The average concentrations of total VOCs ranged from 50.6 to 737.4 μg·m−3, showed significant spatial distributions. The mean values of total benzene, toluene, ethylbenzene and xylene (BTEX) ranged from 6.53 to 92.7 μg·m−3, which were at a normal level when compared with other researches. High levels of benzene were observed in Heze (15.0 μg·m−3), Zibo (28.8 μg·m−3), exceeded US Environment Protect Agency Exposure Inhalation limitation (13.9 μg·m−3), and the highest concentration of benzene in Jining was 16.1 μg·m−3. Based on the specific ratio method, VOCs in Shandong Province were possibly due to coal combustion and biomass burning, local emissions were the dominant sources, while Taian, Heze, Binzou, Jining, Zibo, and Dongying sites were controlled by aging air mass. Fractional aerosol coefficient method was used to estimate SOA formation potential, and the SOA formation potential ranged 0.4–13.4 μg·m−3, and the SOA formation ability in the studied area was at a normal level when compared with other areas. Carcinogenic risks of benzene had definite risk for residents in ZB, and the hazard risk index higher than the threshold value 1.