摘要
The study was carried out in a small urban area of Fuzhou University Town, China. Traditional sampling and analysis techniques, together with multivariate statistical and geostatistical tools, were applied to investigate the spatial distribution and sources of eight heavy metals in the top soil. For polluted soil samples, the method recommended by Ministry of Environmental Protection and the advanced in vitro test method were used for the comparative study of the health risks of soil heavy metals through oral ingestion pathway. The results showed that in general there was no serious heavy metal pollution problem, though the Pb and Cr(Ⅵ) concentrations of some soil samples exceeded the screening values of the latest Chinese national standards for soil environmental quality. Besides, local transportation and vehicles were found to be the main source of heavy metals such as Cd, Cu, Pb, Cr, Ni, and Zn, and this source should be paid due attention. Regarding the results of health risk assessment, the Chinese national recommendation method demonstrated that the noncarcinogenic risk of sample Pb was 1.53 times the acceptable value, and the carcinogenic risks of sample Cd, sample Ni, and two samples Cr(Ⅵ) were 1.01-43.5 times the acceptable values. In comparison, the in vitro test method revealed that only the health risk of sample Pb was noteworthy; in terms of the contributions to the PTWI of Pb, the risks reached 41% for adults and 149% for children in the stomach phase, and significantly decreased to 5% for adults and 18% for children in the following small intestinal phase. The in vitro test method was developed based on the bioaccessibility/bioavailability of soil heavy metals, and thus, it is considered more scientifically sound, without overestimating the health risks. Hence, it is recommended that this test be introduced in future soil pollution surveys. This study provides valuable reference for local urban planning and management, while also serving as an inspiration for the continuous improvement of the soil pollution survey techniques in China. ? 2020, Editorial Board of Journal of Tianjin University(Science and Technology). All right reserved.
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