Insights into As accumulation in soil-groundwater-wheat-hair system of suburban farmland: Distribution, transfer and potential health risk

Abstract

Health risks caused by arsenic (As) contamination in soils and its migration in environmental media have attracted much attention. In this study, suburban farmland of KF city in the ecotone of the Yellow River and Huaihe River Basin was taken as the research area. A series of samples including topsoils (246), profile soils (280), matched wheat grains (22 groups), groundwater (26) and human hair (355) were collected. As distribution and transfer in soil-groundwater-wheat-hair (SGWH) system in typical sites were explored, and comprehensive health risk of As in SGWH system was assessed based on US EPA model and local exposure parameters. The results showed that spatial distribution of total As presented a significant high value area, and higher As contents (in the range of 0.45–29.86 mg kg−1) and bioavailability was mainly in topsoils, which indicated that anthropogenic sources have led to As enrichment in studied area. Also, it was found that the As contents in 95 % of wheat grain samples were higher than that in the control soils, and 9 % groundwater samples were above national Class I standards. Especially, average As content in hair in typical sites was obviously influenced by that in soil, wheat and groundwater. Moreover, As migration curve along soil → wheat (groundwater) → hair appeared an irregular ‘V’ shape, and transfer coefficients of Tf water/soil (10−5), Tf wheat/soil (10−3), Tf hair/soil (10−2), Tf hair/wheat (101) and Tf hair/water (104) presented an obvious increasing trend of magnitude, implying that human body has a higher As enrichment risk. Furthermore, comprehensive health risks for children and adults in typical sites were significant, while wheat is the main risk medium. In general, arsenic accumulation in human hair is good consistent with EPA health risk model, and their combination can better evaluate environmental exposure risk of As.