环境中人为来源的铂族元素及其迁移转化研究进展

Migration and transformation of anthropogenic platinum group elements in environment:A review

铂族元素(PGEs)在汽车尾气催化转换器(VECs)、工业催化剂和制药学领域的广泛应用,致使PGEs尤其是铂(Pt)、钯(Pd)和铑(Rh)在某些区域已经成为新型环境污染物.由于环境样品中Pt/Pd、Pt/Rh与VECs中活性成分比例有较好的相关性,因此PGEs污染主要来源于应用了铂族金属的VECs.研究显示,过去的30年里,气溶胶、水生态系统(河水、雨水、地下水、海水、沉积物)、土壤、路尘和生物有机体等不同环境介质中PGEs浓度均显著增加.人们普遍认为铂族元素是惰性的,暴露于环境中的PGEs的健康风险很小,但PGEs毒性和生物可利用性的研究表明,在多种生物地球化学过程作用下,人为排放的PGEs易发生迁移,转化为毒性更大的形态,增加生物可利用性,通过食物链传递对人类产生潜在的健康风险.本文对不同环境介质中PGEs来源、分布及生物地球化学行为的最新成果进行了总结,认为PGEs人体健康风险标准制定、PGEs标准物质的研制、近海沉积物中PGEs的研究、PGEs对滩涂贝类的毒性、食物中PGEs的污染现状及人体健康风险评估等是今后PGEs研究的重要领域.

Anthropogenic platinum group elements （PGEs） are widely applied in vehicle exhaust catalytic converters （VECs） , industrial catalysts, and pharmaceutics, making the PGEs, especially Pt, Pd, and Rh, become the newly environmental pollutants in some fields. Given the positive correlations between the Pt/Pd and Pt/Rh ratios in various environmental samples and the active components of VECs, the VECs containing PGEs as catalysts are regarded as the primary source of PGEs pollution. Sufficient reports indicated that in the past three decades, there was a significant increase of PGEs concentrations in diverse environmental matrices like airborne particulate matters, aquatic ecosystem components （e. g. , river water, rain water, groundwater, seawater, and sediments）, soils, road dusts, and organisms. It was generally assumed that anthropogenic PGEs behave in inert manner, and the health risks associated with the environmental exposures to PGEs are minimal. However, the recent studies on PGEs toxicity and environmental bioavailabihty indicated that once entering environment, anthropogenic PGEs might easilybe mobilized and transformed into more toxic forms under the actions of various biogeochemical processes, and thereby, enhanced their bioavailability and posed potential health risks to human beings through food chain. This paper summarized the research results about the sources, distribution, and biogeochemical behaviors of PGEs in various environmental media, and it was considered that to establish the standards of PGEs for human health risks, to develop standard substances of PGEs for environmental measurements, to study the PGEs in the sediments of marginal seas, and to assess the toxicity of PGEs to marine mol-lusks, the present contamination status of PGEs in foods, and the risks of PGEs to human health would be the hot research topics in the future.