Effects of soil particle size on metal bioaccessibility and health risk assessment
Effects of soil particle size on metal bioaccessibility and health risk assessment
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DOI：
10.1016/j.ecoenv.2019.109748
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发表时间：
2019-12-30
影响因子：
6.8
通讯作者：
Cheng, Hongguang
中科院分区：
文献类型：
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作者：
Ma, Junwei;Li, Yuqian;Cheng, Hongguang
口服摄入是人类（尤其是儿童）摄入土壤中微量金属的主要暴露途径。不同土壤颗粒尺寸部分中的金属在浓度和性质方面可能有所不同。城市学校/幼儿园土壤样本采集自中国西北地区兰州、中国中部地区武汉和中国东南地区深圳三个城市。将土壤样品按照粒径（<63μm、63-150μm、150-250μm、250-2000μm）进行分类，估算土壤粒径对金属（Cd、Cr、Cu、Ni、Pb、Zn）总含量和生物可及性的影响。根据结果，我们评估了美国环境保护署（EPA）技术审查工作组（TRW）推荐的标准尺寸<150μm（包含<63μm和63-150μm）和欧洲生物可及性研究组（BARGE）推荐的<250μm（包含<63μm、63-150μm和150-250）是否适合最大比例的情况粘在手上的是最细的土（<63μm）。结果表明，不同金属在土壤粒径与含量、土壤粒径与生物可及性之间表现出不同的关系。 Pb和Zn通常在最粗的粒径（250-2000μm）中表现出最大的生物可及性；而最高的 Ni 生物可利用性出现在最细的尺寸 (< 63 μm) 中；其他金属的生物可及性与粒径没有表现出任何明显的关系。当使用推荐土壤粒径范围（<150μm和<250μm）和更细颗粒（<63μm）的生物可接触金属含量评估健康风险时，对儿童的非致癌风险结果没有表现出明显差异，而使用土壤粒径范围<150μm和<250μm可能会低估实际致癌风险。因此，当选择最佳粒径部分来评估口腔土壤摄入的健康风险时，我们建议使用 < 63 μm 土壤部分中的生物可访问金属含量。
Oral ingestion is the main exposure pathway through which humans ingest trace metals in the soil, particularly for children. Metals in different soil particle size fractions may vary in terms of concentration and properties. Urban school/kindergarten soil samples were collected from three cities: Lanzhou in northwest China, Wuhan in central China, and Shenzhen in southeast China. Soil samples were classified according to particle size (< 63 mu m, 63-150 mu m, 150-250 mu m, and 250-2000 mu m) to estimate the effects of soil particle size on the total content and bioaccessibility of metals (Cd, Cr, Cu, Ni, Pb, and Zn). Based on the results, we assessed whether the standard size < 150 mu m (containing < 63 mu m and 63-150 mu m), recommended by the Technical Review Workgroup (TRW) of the Environmental Protection Agency (EPA), and < 250 mu m (containing < 63 mu m, 63-150 mu m, and 150-250) recommended by the Bioaccessibility Research Group of Europe (BARGE), are suitable where the largest proportion adhering to hands is the finest soil (< 63 mu m). The results showed that different metals exhibited different relationships between soil particle size and content and between soil particle size and bioaccessibility. Pb and Zn generally exhibited the greatest bioaccessibility in the coarsest particle sizes (250-2000 mu m); whereas the highest Ni bioaccessibility occurred in the finest sizes (< 63 mu m); the bioaccessibility of other metals did not exhibit any obvious relationships with particle size. When assessing health risks using bioaccessible metal content in the recommended soil particle size ranges (< 150 mu m and < 250 mu m) and in finer particles (< 63 mu m), the results for noncarcinogenic risks to children exhibited no obvious difference, while the actual carcinogenic risks may be underestimated with the use of soil particle size ranges < 150 mu m and < 250 mu m. Therefore, when choosing an optimal particle size fraction to evaluate the health risk of oral soil ingestion, we recommend the use of the bioaccessible metal content in < 63 mu m soil fraction.