1.Southwest Forestry University;2.Yunnan Normal University,;3.yunnan Normal University
Supported by the National Key Research and Development Program of China (2018YFC1800504), the Yunnan Innovative Research Team (202005AE160017), the National Natural Science Foundation of China (41967026), the Scientific and Technological Innovation Top Young Talents Project of National Forestry and Grassland Administration (2020132613), the Yunnan Thousand Youth Talent Program (YNQR-QNRC-2018-049), and the Research Foundation of Yunnan Education Department (2021Y231, 2021Y237)
Recently, the bioaccessibility has been frequently employed to assess the human health risks of oral exposure to heavy metals in soi. However, thebioaccessibility of heavy metals in soils from in vitro gastrointestinal simulation may overestimate their human health risk. Bioavailability, the fraction of heavy metals that reaches the systemic circulation, is considered as an accurate approach to evaluate the potential health risk of contaminants. However, there are few studies on health risk assessment of soils heavy metals from mining sites via bioavailability. Therefore, in this study, five soil samples form mining area of Wenshan, Yunnan Province were collected and the contents of Cd, Pb, Zn and Cu were analyzed using ICP-MS. The bioaccessibility of four heavy metals were detected by in vitro digestion method (SBRC), while the relative bioavailability of heavy metals Cd was determined using Balb/c mice models. The results showed that the soil Cd pollution in this mining area was serious, and the content of Cd was 2.06 mg·kg?1. The bioaccessibility of the four heavy metals in the gastric phase was 24.29～50.55%, 7.68～17.87%, 24.61～32.18%, 7.75～37.87%, respectively. In intestinal phase, they were 22.78～44.32%, 1.64～5.22%, 14.10～28.11%, 8.51～31.49%, respectively. The RBA of Cd measured in vivo was 1.31～48.39% in liver, 2.83～8.58% in kidney, and 4.60～50.95% in liver and kidney, which were ideal target organs for the determination of Cd-RBA. Health risk assessment of the mining soil based on the target heavy metal, bioaccessibility and bioavailability revealed that the assessment risk using the heavy metal aggregates was too high, while the data based on bioaccessibility and bioavailability found that the human health risk was significantly reduced. In conclusion, health risks assessment based on the total amount of heavy metals in soil may be overestimated, and establishment of a new method based on the bioavailability data will be more accurate.
bao xin chen, ma jiao yang, xu wu mei, wang hao ji, wang cheng chen, xiang ping. Human bioavailability and health risk assessment of heavy metals in soils of a mining area of southwest China[J]. Acta Pedologica Sinica,,[In Press]