The objective of this study was to investigate the concentration and spatial distribution patterns of 9 potentially toxic heavy metal elements (As, Cd, Co, Cr, Pb, Cu, Zn, Mn, and Ni) in road dust in the Bayan Obo Mining Region in Inner Mongolia, China. Contamination levels were evaluated using the geoaccumulation index and the enrichment factor. Human health risks for each heavy metal element were assessed using a human exposure model. Results showed that the dust contained significantly elevated heavy metal elements concentrations compared with the background soil. The spatial distribution pattern of all tested metals except for As coincided with the locations of industrial areas while the spatial distribution of As was associated with domestic sources. The contamination evaluation indicated that Cd, Pb, and Mn in road dust mainly originated from anthropogenic sources with a rating of “heavily polluted” to “extremely polluted,” whereas the remaining metals originated from both natural and anthropogenic sources with a level of “moderately polluted”. The non-cancer health risk assessment showed that ingestion was the primary exposure route for all metals in the road dust and that Mn, Cr, Pb, and As were the main contributors to non-cancer risks in both children and adults. Higher HI values were calculated for children (HI=1.89), indicating that children will likely experience higher health risks compared with adults (HI=0.23). The cancer risk assessment showed that Cr was the main contributor, with cancer risks which were 2-3 orders of magnitude higher than those for other metals. Taken in concert, the non-cancer risks posed by all studied heavy metal elements and the cancer risks posed by As, Co, Cr, Cd, and Ni to both children and adults in Bayan Obo Mining Region fell within the acceptable range.
. [J]. 地理学报(英文版), 2015, 25(12): 1439-1451.
LI Kexin,LIANG Tao,YANG Zhiping,YANG Zhiping. Contamination and health risk assessment of heavy metals in road dust in Bayan Obo Mining Region in Inner Mongolia, North China. Journal of Geographical Sciences, 2015, 25(12): 1439-1451.
Apeagyei E, Bank M S, Spengler J D, 2011. Distribution of heavy metals in road dust along an urban-rural gradient in Massachusetts.Atmospheric Environment, 45(13): 2310-2323.http://www.sciencedirect.com/science/article/pii/S1352231010009702
Cheng X, Taylor R N, Li Wet al., 2012. Comparison of fluorite geochemistry from REE deposits in the Panxi region and Bayan Obo, China.Journal of Asian Earth Sciences, 57: 76-89.http://www.sciencedirect.com/science/article/pii/S1367912012002805
Cook A G, Weinstein P, Centeno J A, 2005. Health effects of natural dust.Biological Trace Element Research, 103(1): 1-15.
Csavina J, Field J, Taylor M Pet al., 2012. A review on the importance of metals and metalloids in atmospheric dust and aerosol from mining operations.Science of the Total Environment, 433: 58-73.http://www.sciencedirect.com/science/article/pii/S0048969712008261
Drew L J, Meng Q, Sun W, 1990. The Bayan Obo iron-rare-earth-niobium deposits, Inner Mongolia.China. Lithos, 26(1): 43-65.
Ferreira-Baptista L, De Miguel E, 2005. Geochemistry and risk assessment of street dust in Luanda, Angola: A tropical urban environment.Atmospheric Environment, 39(25): 4501-4512.
Fu K, Su B, He Det al., 2012. Pollution assessment of heavy metals along the Mekong River and dam effects.Journal of Geographical Sciences, 22(5): 874-884.
Gao H, Wang X, Zhang Qet al., 2007. Characteristics of soil background value in Hetao area, Inner Mongolia. Geology and Resources, 16(3): 209-212. (in Chinese)http://en.cnki.com.cn/Article_en/CJFDTOTAL-GJSD200703009.htm
Guo W, Fu R, Zhao Ret al., 2011. Distribution Characteristic and Assessment of Soil Heavy Metal Pollution in the Iron Mining of Baotou in Inner Mongolia.Chinese Journal of Environmental Science, 32(10): 3099-3105. (in Chinese)http://en.cnki.com.cn/Article_en/CJFDTOTAL-HJKZ201110052.htm
IARC (International Agency for Research on Cancer), 2014. Agents Classified by the IARC Monographs, Vol. 1-109.
Liu E, Yan T, Birch Get al., 2014. Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China.Science of the Total Environment, 476: 522-531.http://www.sciencedirect.com/science/article/pii/S0048969714000643
Lu X, Li L Y, Wang Let al., 2009. Contamination assessment of mercury and arsenic in roadway dust from Baoji, China. Atmospheric Environment, 43(15): 2489-2496.
Lu X, Wang L, Lei Ket al., 2009. Contamination assessment of copper, lead, zinc, manganese and nickel in street dust of Baoji, NW China,Journal of Hazardous Materials, 161: 1058-1062.http://www.sciencedirect.com/science/article/pii/S0304389408005980
Moreno T, Karanasiou A, Amato Fet al., 2013. Daily and hourly sourcing of metallic and mineral dust in urban air contaminated by traffic and coal-burning emissions.Atmospheric Environment, 68: 33-44.http://www.sciencedirect.com/science/article/pii/S1352231012010990
Muller G, 1969. Index of geo-accumulation in sediments of the Rhine River.Geo Journal, 2(3): 108-118
Risk Assessment Guidance for Superfund .Volume I: Human Health Evaluation Manual, Part E: Supplemental Guidance for Dermal Risk Assessment. EPA/540/R/99/005, OSWER9285.7-02EP PB99-963312, 2004. Office of Superfund Remediation and Technology Innovation, U.S. Environmental Protection Agency Washington, D.C.
Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A) EPA/540/1-89/002, 1989. Office of Emergency and Remedial Response, U.S. Environmental Protection Agency Washington, D.C.http://homer.ornl.gov/sesa/environment/guidance/cercla/siteclosure/implem.pdf
Shi G, Chen Z, Xu Set al., 2008. Potentially toxic metal contamination of urban soils and roadside dust in Shanghai.China. Environmental Pollution, 156: 251-260.
Si W, Liu J, Cai Let al., 2015. Health risks of metals in contaminated farmland soils and spring wheat irrigated with Yellow River water in Baotou, China.Bulletin of Environmental Contamination and Toxicology, 94(2): 214-219.http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM25476736
Sun C, Bi C, Chen Zet al., 2010. Assessment on environmental quality of heavy metals in agricultural soils of Chongming Island, Shanghai City.Journal of Geographical Sciences, 20(1): 135-147.
Supplemental Guidance for Developing Soil Screening Level for Superfund Sites. OSWER9355.4-24, 2001. Office of Solid Waste and Emergency Response, Environmental Protection Agency Washington, D.C.
Supplemental Guidance to RAGS: Calculating the Concentration Term. PB92-963373, 1992. Office of Solid Waste and Emergency Response, Environmental Protection Agency Washington, D.C.
Valko M, Rhodes C J, Moncol Jet al., 2006. Free radicals, metals and antioxidants in oxidative stress-induced cancer.Chemico-biological Interactions, 160(1): 1-40.http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM16430879
Wang L, Guo Z, Xiao Xet al., 2008. Heavy metal pollution of soils and vegetables in the midstream and downstream of the Xiangjiang River, Hunan Province.Journal of Geographical Sciences, 18(3): 353-362.
Wang L, Liang T, Zhang Qet al., 2014. Rare earth element components in atmospheric particulates in the Bayan Obo mine region. Environmental Research, 131: 64-70.http://www.sciencedirect.com/science/article/pii/S0013935114000279
Wei B, Jiang F, Li Wet al., 2009. Spatial distribution and contamination assessment of heavy metals in urban road dusts from Urumqi, NW China.Microchemical Journal, 93: 147-152.http://www.sciencedirect.com/science/article/pii/S0026265X0900085X
Wu C, 2008. Bayan Obo Controversy: Carbonatites versus Iron Oxide‐Cu‐Au‐(REE‐U).Resource Geology, 58(4): 348-354. (in Chinese)http://onlinelibrary.wiley.com/doi/10.1111/j.1751-3928.2008.00069.x/full
Xu S, Tao S, 2004. Coregionalization analysis of heavy metals in the surface soil of Inner Mongolia.Science of the Total Environment, 320: 73-87.http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM14987928
Zhang J, Zheng C, Liu Jet al., 2002. Advance of pollution and retention of arsenic in coal combustion.Coal Conversion, 25(2): 23-28. (in Chinese)http://en.cnki.com.cn/Article_en/CJFDTOTAL-MTZH200202004.htm
Zhang M, Wang H, 2009. Concentrations and chemical forms of potentially toxic metals in road-deposited sediments from different zones of Hangzhou, China.Journal of Environmental Sciences, 21: 625-631.
Zheng G, Yue L, Li Zet al., 2006. Assessment on heavy metals pollution of agricultural soil in Guanzhong district.Journal of Geographical Sciences, 16(1): 105-113.
Zheng N, Liu J, Wang Qet al., 2010a. Health risk assessment of heavy metal exposure to street dust in the zinc smelting district, northeast of China.Science of the Total Environment, 408(4): 726-733.http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM19926116
Zheng N, Liu J, Wang Qet al., 2010b. Heavy metals exposure of children from stairway and sidewalk dust in the smelting district, northeast of China.Atmospheric Environment, 44(27): 3239-3245.