School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
Ecotoxicol Environ Saf. 2016 Feb;124:460-469. doi: 10.1016/j.ecoenv.2015.11.023. Epub 2015 Nov 28.
Acid mine drainages (AMD) contain high concentrations of heavy metals, and their discharges into streams and rivers constitute serious environmental problems. This article examines the effects of AMD on soil, plant and human health at Dabaoshan mine in Guangdong Province, China. Although the large scale mining was stopped in 2011, the heavy metal pollution in soil continues to endanger crops and human health in that region. The objectives of this study were to elucidate distribution and migration of Cd, Cu, Zn, As and Pb and associated health implications to local inhabitants. We collected and analyzed 74 crop samples including 28 sugarcane, 30 vegetables, 16 paddy rice and the corresponding soil samples, used correlation and linear relationship for transformation process analysis, and applied carcinogenic and non-carcinogenic risk for hazard evaluation. Results showed that the local soils were heavily polluted with Cd, Cu and As (especially for Cd) and the mean Igeo value was as high as 3.77. Cadmium, Cu, and Zn in rice and vegetables were comparable with those found four years ago, while As and Pb in edible parts were 2 to 5 times lower than before. The root uptake of Cd and Zn contributed mainly to their high concentrations in crops due to high exchangeable fraction of soil, while leafy vegetables accumulated elevated As and Pb contents mainly due to the atmospheric deposition. Metal concentrations in sugarcane roots were higher than those in rice and vegetable roots. The risk assessment for crops consumption showed that the hazard quotients values were of 21 to 25 times higher than the threshold level for vegetables and rice, indicating a potential non-carcinogenic risk to the consumers. The estimated mean total cancer risk value of 0.0516 more than 100 times exceeded the USEPA accepted risk level of 1×10(-4), indicating unsuitability of the soil for cultivating the food crops. Therefore, the local agricultural and the land-use policies need to be reevaluated.
酸性矿山排水（AMD）含有高浓度的重金属，其排入溪流和河流会构成严重的环境问题。本文研究了广东省大宝山矿 AMD 对土壤、植物和人体健康的影响。尽管该矿已于 2011 年停止大规模开采，但土壤中的重金属污染仍在继续危害该地区的农作物和人类健康。本研究的目的是阐明 Cd、Cu、Zn、As 和 Pb 的分布和迁移及其对当地居民的健康影响。我们收集并分析了 74 种农作物样本，包括 28 种甘蔗、30 种蔬菜、16 种水稻及其相应的土壤样本，利用相关性和线性关系进行转化过程分析，并应用致癌和非致癌风险进行危害评价。结果表明，当地土壤受到 Cd、Cu 和 As 的严重污染（尤其是 Cd），其平均 Igeo 值高达 3.77。水稻和蔬菜中的 Cd、Cu 和 Zn 与四年前的发现相当，而食用部分的 As 和 Pb 则比以前低 2 至 5 倍。由于土壤可交换态较高，根对 Cd 和 Zn 的吸收主要导致其在作物中浓度较高，而叶菜类蔬菜则主要由于大气沉降积累了较高的 As 和 Pb 含量。甘蔗根中的金属浓度高于水稻和蔬菜根中的浓度。食用作物的风险评估表明，蔬菜和水稻的危害商值是阈值的 21 至 25 倍，表明消费者存在潜在的非致癌风险。估计的平均总癌症风险值 0.0516 超过 100 倍，超过了 USEPA 接受的风险水平 1×10(-4)，表明土壤不适合种植农作物。因此，需要重新评估当地的农业和土地利用政策。
