College of Environment and Climate, Guangdong Provincial Key Laboratory of Environmental Pollution and Health, Jinan University, China.
Chemosphere. 2024 Jun;358:142192. doi: 10.1016/j.chemosphere.2024.142192. Epub 2024 May 1.
Current human health risk assessments of soil arsenic (As) contamination rarely consider bioaccessibility (IVBA), which may overestimate the health risks of soil As. The IVBA of As (As-IVBA) may differ among various soil types. This investigation of As-IVBA focused As from geological origin in a typical subtropical soil, lateritic red soil, and its risk control values. The study used the SBRC gastric phase in vitro digestion method and As speciation sequential extraction based upon phosphorus speciation extraction method. Two construction land sites (CH and HD sites) in the Pearl River Delta region were surveyed. The results revealed a high content of residual As (including scorodite, mansfieldite, orpiment, realgar, and aluminum arsenite) in the lateritic red soils at both sites (CH: 84.9%, HD: 91.7%). The content of adsorbed aluminum arsenate (CH: 3.24%, HD: 0.228%), adsorbed ferrum arsenate (CH: 8.55%, HD: 5.01%), and calcium arsenate (CH: 7.33%, HD: 3.01%) were found to be low. The bioaccessible As content was significantly positively correlated with the As content in adsorbed aluminum arsenate, adsorbed ferrum arsenate, and calcium arsenate. A small portion of these sequential extractable As speciation could be absorbed by the human body (CH: 14.9%, HD: 3.16%), posing a certain health risk. Adsorbed aluminum arsenate had the highest IVBA, followed by calcium arsenate, and adsorbed ferrum arsenate had the lowest IVBA. The aforementioned speciation characteristics of As from geological origin in lateritic red soil contributed to its lower IVBA compared to other soils. The oxidation state of As did not significantly affect As-IVBA. Based on As-IVBA, the carcinogenic and non-carcinogenic risks of soil As in the CH and HD sites decreased greatly in human health risk assessment. The results suggest that As-IVBA in lateritic red soil should be considered when assessing human health risks on construction land.
当前的土壤砷（As）污染人体健康风险评估很少考虑生物可给性（IVBA），这可能会高估土壤 As 的健康风险。不同土壤类型的 As-IVBA 可能不同。本研究重点研究了源自地质的 As-IVBA，以及其风险控制值。研究采用 SBRC 胃相体外消化法和基于磷形态提取法的 As 形态顺序提取法。对珠江三角洲地区的两个建设用地（CH 和 HD 场地）进行了调查。结果表明，两个场地的红土中的残余 As（包括硫砷铁矿、砷铅矿、雌黄、雄黄和铝砷酸）含量很高（CH：84.9%，HD：91.7%）。吸附态的铝砷酸（CH：3.24%，HD：0.228%）、吸附态的铁砷酸（CH：8.55%，HD：5.01%）和钙砷酸（CH：7.33%，HD：3.01%）含量较低。可生物利用的 As 含量与吸附态的铝砷酸、吸附态的铁砷酸和钙砷酸的 As 含量呈显著正相关。这些顺序提取的 As 形态中的一小部分可以被人体吸收（CH：14.9%，HD：3.16%），从而构成一定的健康风险。吸附态的铝砷酸具有最高的 IVBA，其次是钙砷酸，而吸附态的铁砷酸具有最低的 IVBA。红土中源自地质的 As 的上述形态特征导致其 IVBA 低于其他土壤。As 的氧化态对 As-IVBA 没有显著影响。基于 As-IVBA，在人类健康风险评估中，CH 和 HD 场地土壤 As 的致癌和非致癌风险大大降低。结果表明，在评估建设用地的人类健康风险时，应考虑红土中的 As-IVBA。
