State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Int J Environ Res Public Health. 2021 Jan 21;18(3):893. doi: 10.3390/ijerph18030893.
Indigenous zinc smelting (IZS) is a backward technique that releases a great deal of heavy metal(loid)s into the environment. However, the contamination of heavy metal(loid)s in ground dust and the associated health risks in such areas are poorly known. In this study, a former IZS area in Guizhou, China, was surveyed during 2008-2018 with 15 elements (Ag, As, Bi, Cd, Co, Cr, Cu, Hg, In, Ni, Pb, Sb, Sn, Tl, Zn) being analyzed. The results indicate that most elements (e.g., Ag, As, Cd, Cu, Pb, Sb, Sn, Zn) in ground dust decreased significantly after the cessation of the IZS in 2006; nevertheless, some elements still remained at relatively high levels in 2018, e.g., Pb (average: 762 ± 647 mg/kg), Zn (average: 1287 ± 753 mg/kg), Cd (average: 7.76 ± 5.06 mg/kg), and As (average: 41.9 ± 34.8 mg/kg), indicating they might come from the local contaminated soils, slag residues and smelting potteries. In terms of the impacts on human health, children have both higher non-carcinogenic and carcinogenic risks than that of adults, with the latter subpopulation having a lower risk than the threshold values. Pb and As were the two elements with the highest non-carcinogenic risk for children, the hazard index of local children was still higher than the threshold of 1 (e.g., 1.43 for As, 2.09 for Pb) in 2018. The carcinogenic risk of As exposure to children dropped more than two times to 6.42 × 10 in 2018, which falls below the tolerable range (10-10). This study revealed that although the concentration of heavy metal(loid)s in ground dust and linked health risk in the IZS area has reduced dramatically after the cessation of IZS, continued removal of slag residues and smelting potteries is necessary for further decreasing the human health risk.
原生锌冶炼（IZS）是一种落后的技术，会向环境中释放大量重金属（类）。然而，人们对这种地区的土壤灰尘中重金属（类）的污染及其相关健康风险知之甚少。在本研究中，于 2008 年至 2018 年对中国贵州的一个原生锌冶炼区进行了调查，共分析了 15 种元素（Ag、As、Bi、Cd、Co、Cr、Cu、Hg、In、Ni、Pb、Sb、Sn、Tl、Zn）。结果表明，IZS 于 2006 年停止后，大部分土壤灰尘中的元素（如 Ag、As、Cd、Cu、Pb、Sb、Sn、Zn）含量显著降低；然而，2018 年仍有一些元素含量保持在较高水平，例如 Pb（平均值：762±647mg/kg）、Zn（平均值：1287±753mg/kg）、Cd（平均值：7.76±5.06mg/kg）和 As（平均值：41.9±34.8mg/kg），表明这些元素可能来自于当地受污染的土壤、炉渣残余物和冶炼锅。就对人类健康的影响而言，儿童的非致癌和致癌风险均高于成人，而后者的风险低于阈值。Pb 和 As 是儿童面临的两种非致癌风险最高的元素，2018 年当地儿童的危害指数仍高于 1（例如，As 为 1.43，Pb 为 2.09）。2018 年，儿童接触 As 的致癌风险下降了两倍多，至 6.42×10-6，低于可接受范围（10-1）。本研究表明，尽管 IZS 停止后，土壤灰尘中重金属（类）的浓度及其相关健康风险已显著降低，但仍需继续清除炉渣残余物和冶炼锅，以进一步降低人类健康风险。
