广西某矿区附近居民区道路灰尘重金属污染健康风险评价
Health Risk Assessment of Heavy Metals from Road Dust in Residential Areas near a Mining Area of Guangxi
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摘要:
目的 调查广西南丹某矿区附近居民区道路灰尘中重金属污染水平，评估其对成人和儿童产生的潜在健康风险。
方法 采集广西南丹某矿区附近居民区道路灰尘样品46 份，测定砷（As）、镉（Cd）、铅（Pb）、锑（Sb）、汞（Hg）的含量，并采用美国环保署（USEPA）人体暴露健康风险评价方法评估成人和儿童经多种途径暴露道路灰尘重金属的非致癌风险和致癌风险。
结果 广西南丹某矿区附近居民区道路灰尘As、Cd、Pb、Sb 和Hg 含量平均值分别为1 332.81、38.00、650.88、570.20 和2.63 mg/kg，分别是广西土壤背景值的99.5 倍、481.0 倍、31.8 倍、191.3 倍和2.2 倍。As、Cd 和Sb 超标率均为100.0%，Pb 和Hg 的超标率分别55.6%和77.8%。无论成人还是儿童，手-口途径摄入是道路灰尘重金属引起非致癌风险和致癌风险的最主要途径。儿童的非致癌风险和致癌风险均大于成人，总非致癌风险次序为As > Sb > Pb > Cd > Hg，总致癌风险As > Cd > Pb。儿童和成人总非致癌风险分别为65.4 和11.2，总致癌风险分别为2.82×10-2 和4.83×10-3。手- 口摄入途径成人As 和Sb 的非致癌风险为7.51 和2.41，儿童As、Sb 和Pb 分别为44.90、14.40 和1.84，均超出了可接受的非致癌风险（> 1）。无论成人还是儿童，手- 口摄入或经皮肤接触暴露As 和Cd 的致癌风险均超出可接受的致癌风险水平（10-4）。
结论 研究区域道路灰尘重金属污染严重，道路灰尘重金属污染对当地居民健康存在危害，应当引起重视。
Abstract:Objective To evaluate the health risks to adults and children caused by heavy metals in road dust in residential areas near a mining area of Nandan, Guangxi.
Method Road dust samples (
n =46) were collected in selected residential areas near a mining area in Nandan to evaluate levels of arsenic (As), cadmium (Cd), lead (Pb), stibium (Sb), and mercury (Hg). The cancer and non-cancer risks of heavy metals in road dust for local children and adults were estimated using United States Environmental Protection Agency (USEPA) health risk assessment model.Result The average levels of As, Cd, Pb, Sb, and Hg in road dust in residential areas near a mining area of Nandan were 1 332.81, 38.00, 650.88, 570.20, and 2.63 mg/kg, which were 99.5, 481.0, 31.8, 191.3, and 2.2 times of the soil background values of corresponding heavy metals in Guangxi, respectively. The heavy metals levels of all (100.0%) road dusts samples exceeded the national standard limits for As, Cd, and Sb; besides, the heavy metals levels of 55.6% and 77.8% of the samples exceeded the limits for Pb and Hg, respectively. By hand-mouth pathway, both non-cancer and cancer risks for children were higher than those for adults. The order of the total non-cancer risks of heavy metals from high to low was As > Sb > Pb > Cd > Hg, while that of the total cancer risks was As > Pb > Cd. The total non-cancer risk for adults and children were 11.2 and 65.4, and the total cancer risk were 4.83×10-3 and 2.82×10-2, respectively. The non-caner risks of As and Sb through hand-mouth ingestion for adults were 7.51 and 2.41 respectively; the non-caner risks for As, Sb, and Pb through hand-mouth ingestion for children were 44.90, 14.40, and 1.84, respectively; all exceeded the acceptable non-cancer risk level (> 1). The cancer risks of As and Cd through hand-mouth ingestion and dermal exposure in adults and children all exceeded the acceptable carcinogenic risk level (10-4).
Conclusion The contamination of heavy metals in road dust in the study area is severe. Attention should be paid to the health risks caused by heavy metals to the residents.
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