Assessment of arsenic and lead bioaccessibility in co-contaminated soil using a coupled PBET-SHIME model

doi:10.7523/j.ucas.2026.001

Abstract

Abstract: Hand-to-mouth ingestion is a significant pathway for human exposure to soil heavy metals. The bioaccessibility of heavy metals is a critical parameter for human health risk assessment. Research on the bioaccessibility of arsenic (As) and lead (Pb) and their potential interactions in co-contaminated soils is limited. This study utilized three farmland soils with different pH levels (Jiangxi Yingtan, JX; Zhejiang Jiaxing, ZJ; Inner Mongolia Chifeng, NM). As and Pb were artificially spiked into the soils, which were then aged for one month to create co-contaminated samples with varying concentrations of As (50, 100, and 200 mg·kg^-1) and Pb (200, 400, and 800 mg·kg^-1). The PBET and SHIME model were employed to investigate the changes and interactions in the bioaccessibility of As and Pb during the gastric, small intestinal, and colon phases. The results indicated that the bioaccessibility of As from the gastric to the small intestinal phase increased in JX soil, showed no significant change in ZJ soil, and decreased in NM soil. From the small intestinal to the colon phase, As bioaccessibility exhibited an overall increasing trend. In contrast, the bioaccessibility of Pb decreased significantly (p < 0.05) throughout the progression from the gastric to the small intestinal and then to the colon phase. No significant interaction between As and Pb was observed during the gastric and small intestinal phases. However, in the colon phase, the bioaccessibility of As gradually decreased with the addition and increasing concentration of Pb. At the highest Pb addition level (800 mg·kg^-1), the bioaccessibility of As in the three soils was reduced by 16.8% to 24.8% (p < 0.001), accompanied by a decrease in the concentration of As(Ⅲ). These findings clarify the variations in bioaccessibility and the interaction between As and Pb in co-contaminated soils, providing important scientific insights for the accurate assessment of human health risks associated with As and Pb co-contamination.

Key words: arsenic, lead, co-contaminated soils, bioaccessibility, SHIME model

CLC Number:

YAN Shibo, XU Zelin, TIAN Wen, CHANG Xuhui, YANG Maolin, CAI Xiaolin, YIN Naiyi, CUI Yanshan. Assessment of arsenic and lead bioaccessibility in co-contaminated soil using a coupled PBET-SHIME model[J]. Journal of University of Chinese Academy of Sciences, DOI: 10.7523/j.ucas.2026.001.

References

[1] Hou D Y, Jia X Y, Wang L W, et al.Global soil pollution by toxic metals threatens agriculture and human health[J]. Science, 2025, 388(6744): 316-321. DOI: 10.1126/science.adr5214.
[2] Mondal S, Mondal T, Pal P, et al.Bioprotective mechanisms of Enterobacter sp. against arsenic, cadmium, and lead toxicity and its potential role in soil bioremediation[J]. Journal of Environmental Chemical Engineering, 2025, 13(2): 115432. DOI: 10.1016/j.jece.2025.115432.
[3] Li H B, Chen X Q, Wang J Y, et al.Antagonistic interactions between arsenic, lead, and cadmium in the mouse gastrointestinal tract and their influences on metal relative bioavailability in contaminated soils[J]. Environmental Science & Technology, 2019, 53(24): 14264-14272. DOI: 10.1021/acs.est.9b03656.
[4] Zhang Y L, Fu P F, Li S, et al.Remediation of As, Sb, and Pb co-contaminated mining soils by using Fe/C based solid wastes: Synergistic effects and field applications[J]. Chemical Engineering Journal, 2024, 498: 155476. DOI: 10.1016/j.cej.2024.155476.
[5] Fan X L, Wu X, Wang X Z, et al.Eliminating the stabilizer antagonistic effects for efficiently stabilizing Pb and As co-contaminated soil by innovative stepwise steam flash heating[J]. Journal of Hazardous Materials, 2024, 473: 134627. DOI: 10.1016/j.jhazmat.2024.134627.
[6] Gankhurel B, Fukushi K, Akehi A, et al.Comparison of chemical speciation of lead, arsenic, and cadmium in contaminated soils from a historical mining site: Implications for different mobilities of heavy metals[J]. ACS Earth and Space Chemistry, 2020, 4(7): 1064-1077. DOI: 10.1021/acsearthspacechem.0c00087.
[7] Zeng J Q, Luo X H, Cheng Y Z, et al.Spatial distribution of toxic metal(loid)s at an abandoned zinc smelting site, Southern China[J]. Journal of Hazardous Materials, 2022, 425: 127970. DOI: 10.1016/j.jhazmat.2021.127970.
[8] 生态环境部, 国家市场监督管理总局. 土壤环境质量农用地土壤污染风险管控标准: GB 15618—2018[S]. 北京: 中国标准出版社, 2018.
[9] Wang H Y, Chen S, Xue R Y, et al.Arsenic ingested early in life is more readily absorbed: Mechanistic insights from gut microbiota, gut metabolites, and intestinal morphology and functions[J]. Environmental Science & Technology, 2023, 57(2): 1017-1027. DOI: 10.1021/acs.est.2c04584.
[10] Xu L Q, Polya D A, Li Q, et al.Association of low-level inorganic arsenic exposure from rice with age-standardized mortality risk of cardiovascular disease (CVD) in England and Wales[J]. Science of The Total Environment, 2020, 743: 140534. DOI: 10.1016/j.scitotenv.2020.140534.
[11] Khan K M, Chakraborty R, Bundschuh J, et al.Health effects of arsenic exposure in Latin America: An overview of the past eight years of research[J]. Science of The Total Environment, 2020, 710: 136071. DOI: 10.1016/j.scitotenv.2019.136071.
[12] 王振洲, 崔岩山, 张震南, 等. 生菜和油菜中砷的生物可给性及其对人体的健康风险评估[J]. 中国科学院大学学报, 2015, 32(6): 735-742. DOI: 10.7523/j.issn.2095-6134.2015.06.003.
[13] Marshall A T, Betts S, Kan E C, et al.Association of lead-exposure risk and family income with childhood brain outcomes[J]. Nature Medicine, 2020, 26(1): 91-97. DOI: 10.1038/s41591-019-0713-y.
[14] O'Connor D, Hou D Y, Ok Y S, et al. The effects of iniquitous lead exposure on health[J]. Nature Sustainability, 2020, 3(2): 77-79. DOI: 10.1038/s41893-020-0475-z.
[15] Xu X Y, Qian Q, Shi Y, et al.Cola beverage reduces risk of lead poisoning from accidental ingestion of contaminated soil particles in rat and swine models[J]. Nature Communications, 2025, 16(1): 755. DOI: 10.1038/s41467-025-56138-9.
[16] Lin C Y, Wang B B, Cui X Y, et al.Estimates of soil ingestion in a population of Chinese children[J]. Environmental Health Perspectives, 2017, 125(7): 077002. DOI: 10.1289/EHP930.
[17] 张玉康, 瞿福, 阮若涵, 等. 重金属生物可给性体外模拟方法研究进展[J]. 生态毒理学报, 2025, 20(1): 221-237. DOI: 10.7524/AJE.1673-5897.20240808002.
[18] Sowers T D, Blackmon M D, Wilkin R T, et al.Lead speciation, bioaccessibility, and sources for a contaminated subset of house dust and soils collected from similar United States residences[J]. Environmental Science & Technology, 2024, 58(21): 9339-9349. DOI: 10.1021/acs.est.4c01594.
[19] Du H L, Yin N Y, Cai X L, et al.Lead bioaccessibility in farming and mining soils: The influence of soil properties, types and human gut microbiota[J]. Science of The Total Environment, 2020, 708: 135227. DOI: 10.1016/j.scitotenv.2019.135227.
[20] Juhasz A L, Weber J, Smith E, et al.Assessment of four commonly employed in vitro arsenic bioaccessibility assays for predicting in vivo relative arsenic bioavailability in contaminated soils[J]. Environmental Science & Technology, 2009, 43(24): 9487-9494. DOI: 10.1021/es902427y.
[21] Xia Q, Peng C, Lamb D, et al.Bioaccessibility of arsenic and cadmium assessed for in vitro bioaccessibility in spiked soils and their interaction during the Unified BARGE Method (UBM) extraction[J]. Chemosphere, 2016, 147: 444-450. DOI: 10.1016/j.chemosphere.2015.12.091.
[22] Xia Q, Peng C, Lamb D, et al.Effects of arsenic and cadmium on bioaccessibility of lead in spiked soils assessed by Unified BARGE Method[J]. Chemosphere, 2016, 154: 343-349. DOI: 10.1016/j.chemosphere.2016.03.133.
[23] Xia Q, Lamb D, Peng C, et al.Interaction effects of As, Cd and Pb on their respective bioaccessibility with time in co-contaminated soils assessed by the Unified BARGE Method[J]. Environmental Science and Pollution Research, 2017, 24(6): 5585-5594. DOI: 10.1007/s11356-016-8292-7.
[24] Ollson C J, Smith E, Juhasz A L.Can in vitro assays account for interactions between inorganic co-contaminants observed during in vivo relative bioavailability assessment?[J]. Environmental Pollution, 2018, 233: 348-355. DOI: 10.1016/j.envpol.2017.10.089.
[25] Liang S, Guan D X, Li J, et al.Effect of aging on bioaccessibility of arsenic and lead in soils[J]. Chemosphere, 2016, 151: 94-100. DOI: 10.1016/j.chemosphere.2016.02.070.
[26] Yin N Y, Zhang Z N, Cai X L, et al.In vitro method to assess soil arsenic metabolism by human gut microbiota: Arsenic speciation and distribution[J]. Environmental Science & Technology, 2015, 49(17): 10675-10681. DOI: 10.1021/acs.est.5b03046.
[27] Tang X Y, Cui Y S, Duan J, et al.Pilot study of temporal variations in lead bioaccessibility and chemical fractionation in some Chinese soils[J]. Journal of Hazardous Materials, 2008, 160(1): 29-36. DOI: 10.1016/j.jhazmat.2008.02.076.
[28] Tang X Y, Zhu Y G, Shan X Q, et al.The ageing effect on the bioaccessibility and fractionation of arsenic in soils from China[J]. Chemosphere, 2007, 66(7): 1183-1190. DOI: 10.1016/j.chemosphere.2006.07.096.
[29] Ruby M V, Davis A, Schoof R, et al.Estimation of lead and arsenic bioavailability using a physiologically based extraction test[J]. Environmental Science & Technology, 1996, 30(2): 422-430. DOI: 10.1021/es950057z.
[30] Yin N Y, Du H L, Zhang Z N, et al. Variability of arsenic bioaccessibility and metabolism in soils by human gut microbiota using different in vitro methods combined with SHIME[J]. Science of The Total Environment, 2016, 566-567: 1670-1677. DOI: 10.1016/j.scitotenv.2016.06.071.
[31] Laird B D, Van de Wiele T R, Corriveau M C, et al. Gastrointestinal microbes increase arsenic bioaccessibility of ingested mine tailings using the simulator of the human intestinal microbial ecosystem[J]. Environmental Science & Technology, 2007, 41(15): 5542-5547. DOI: 10.1021/es062410e.
[32] Oremland R S, Stolz J F.Arsenic, microbes and contaminated aquifers[J]. Trends in Microbiology, 2005, 13(2): 45-49. DOI: 10.1016/j.tim.2004.12.002.
[33] Zhang S X, Deng Z W, Yin X X, et al.Bioaccessibility of lead and cadmium in soils around typical lead-acid power plants and their effect on gut microorganisms[J]. Environmental Geochemistry and Health, 2024, 46(3): 107. DOI: 10.1007/s10653-023-01840-0.
[34] Cai M F, McBride M B, Li K M, et al. Bioaccessibility of as and Pb in orchard and urban soils amended with phosphate, Fe oxide and organic matter[J]. Chemosphere, 2017, 173: 153-159. DOI: 10.1016/j.chemosphere.2017.01.049.
[35] Xie K T, Xie N G, Liao Z Y, et al.Bioaccessibility of arsenic, lead, and cadmium in contaminated mining/smelting soils: Assessment, modeling, and application for soil environment criteria derivation[J]. Journal of Hazardous Materials, 2023, 443: 130321. DOI: 10.1016/j.jhazmat.2022.130321.
[36] Zia M H, Codling E E, Scheckel K G, et al.In vitro and in vivo approaches for the measurement of oral bioavailability of lead (Pb) in contaminated soils: A review[J]. Environmental Pollution, 2011, 159(10): 2320-2327. DOI: 10.1016/j.envpol.2011.04.043.
[37] Bolan S, Seshadri B, Grainge I, et al.Gut microbes modulate bioaccessibility of lead in soil[J]. Chemosphere, 2021, 270: 128657. DOI: 10.1016/j.chemosphere.2020.128657.
[38] Ruby M V, Schoof R, Brattin W, et al.Advances in evaluating the oral bioavailability of inorganics in soil for use in human health risk assessment[J]. Environmental Science & Technology, 1999, 33(21): 3697-3705. DOI: 10.1021/es990479z.
[39] Liu H S, Fu S L, Zhang S S, et al.Lead induces structural damage, microbiota dysbiosis and cell apoptosis in the intestine of juvenile bighead carp (Hypophthalmichthys nobilis)[J]. Aquaculture, 2020, 528: 735573. DOI: 10.1016/j.aquaculture.2020.735573.
[40] Wang N N, Sheng Z J, Zhou S M, et al.Chronic lead exposure exacerbates hepatic glucolipid metabolism disorder and gut microbiota dysbiosis in high-fat-diet mice[J]. Food and Chemical Toxicology, 2022, 170: 113451. DOI: 10.1016/j.fct.2022.113451.
[41] Yin N Y, Chang X H, Xiao P, et al.Role of microbial iron reduction in arsenic metabolism from soil particle size fractions in simulated human gastrointestinal tract[J]. Environment International, 2023, 174: 107911. DOI: 10.1016/j.envint.2023.107911.
[42] Müller V, Chavez-Capilla T, Feldmann J, et al.Increasing temperature and flooding enhance arsenic release and biotransformations in Swiss soils[J]. Science of The Total Environment, 2022, 838: 156049. DOI: 10.1016/j.scitotenv.2022.156049.
[43] Huang H, Jia Y, Sun G X, et al.Arsenic speciation and volatilization from flooded paddy soils amended with different organic matters[J]. Environmental Science & Technology, 2012, 46(4): 2163-2168. DOI: 10.1021/es203635s.