Temporal variations of levels and sources of health risk associated with heavy metals in road dust in Beijing from May 2016 to April 2018

• Published in: Chemosphere (Oxford) 2021-05, Vol.270, p.129434, Article 129434
• Main Authors: Men, Cong, Wang, Yifan, Liu, Ruimin, Wang, Qingrui, Miao, Yuexi, Jiao, Lijun, Shoaib, Muhammad, Shen, Zhenyao
• Format: Article
• Language: English
• Subjects: Adult; Beijing; Child; China; Cities; Dust - analysis; Environmental Monitoring; Heavy metals; Humans; Metals, Heavy - analysis; Metals, Heavy - toxicity; Risk Assessment; Road dust; Source-specific health risk; Temporal variation; Uncertainty analysis; Vehicle Emissions
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.129434

To analyze the temporal variations of heavy metals, health risk, and source-specific health risk, 24 road dust samples were collected from Beijing in each month in two years. The temporal variations of Hg, Pb, and Ni were higher than other heavy metals. Most heavy metals reached their highest concentrations either in winter or in spring, then the concentrations decreased and reached the lowest values in autumn. Human health risk assessment (HHRA) model showed that As, Cr, and Ni might pose cautionary carcinogenic risk (CR) to children (CR > 10−6). CR for adults were only 0.15 to 0.19 times of that for children. Four sources were identified based on positive matrix factorization model and HHRA model, they were traffic exhaust, fuel combustion, construction, and use of pesticides and fertilizers. Influenced by the difference of carcinogenicity of heavy metals, traffic exhaust contributed the largest to heavy metals (36.02%, over 42.24% higher than other sources), while contributions of fuel combustion to CR (36.95%) was similar to traffic exhaust (37.17%). Monte-Carlo simulation showed that the 95th percentile of probability density functions of CR posed by Cr and Ni from each source were 9.90 × 10−5 to 2.64 × 10−4, posing cautionary carcinogenic risk to children. The seasonal change of CR varied among different sources. CR from use of pesticides and fertilizers in spring was 35.06 times of that in winter, and that from fuel combustion in winter was 1.15–2.40 times of that in other seasons. CR from each source was sensitive to ingestion rate and skin adherence factor. [Display omitted] •Temporal variations of source-specific health risk of metals in two years were analyzed.•There were four sources, and each source of Cr and Ni led to cautionary CR to children.•Traffic exhaust impacted most on contents, fuel combustion impacted largely on risk.•Health risks changed with seasons, and the seasonal change varied among different sources.