School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 201306, China.
Ecotoxicol Environ Saf. 2020 May;194:110411. doi: 10.1016/j.ecoenv.2020.110411. Epub 2020 Mar 6.
Accidental ingestion of Pb-contaminated soil particles by direct hand-to-mouth activity or by swallowing airborne dust particles is important pathway of human exposure to Pb. Appropriate evaluation of Pb risk to human is important in determining whether the soil needs remediation or not, however, there is paucity of data about the dietary influences on Pb bioaccessibility (Pb-BA) and transformation in humans. This study chose two typical foods, spinach and cola, representing vegetable and soft drink, respectively, and investigated their effects on Pb species in gastrointestinal tract using the physiologically based extraction test. Results showed that ingestion of spinach and cola decreased the Pb-BA by 52%-94% in the gastric phase and by 38%-95% in the intestinal phase, respectively. The reduction of Pb-BA by spinach was attributed to the precipitation of Pb with phosphorus in spinach and the sorption of Pb by the generated hydrolysate and un-hydrolysate from spinach in gastrointestinal tract. Cola decreased Pb-BA mainly via formation of insoluble Pb phosphates precipitates. Analysis of X-ray diffraction and MINTEQ modeling demonstrated that the dissolved Pb was transformed to precipitated or sorbed Pb with intake of cola or spinach. Our findings suggest that dietary habit greatly influence the speciation and subsequent Pb-BA in the gastrointestinal tract, which should be incorporated into human health risk assessment of Pb-contaminated soil.
人类经口摄入受 Pb 污染的土壤颗粒或吞食空气中的粉尘颗粒，是 Pb 暴露的重要途径。因此，评估 Pb 对人体的风险对于确定土壤是否需要修复非常重要。然而，关于饮食对 Pb 生物可给性（Pb-BA）和转化的影响的数据却很少。本研究选择了两种典型的食物，即菠菜和可乐，分别代表蔬菜和软饮料，使用基于生理学的提取测试来研究它们对胃肠道中 Pb 形态的影响。结果表明，摄入菠菜和可乐分别使胃相中 Pb-BA 降低了 52%-94%，肠相中降低了 38%-95%。菠菜降低 Pb-BA 的原因是菠菜中的磷与 Pb 发生沉淀，以及在胃肠道中生成的水解产物和未水解产物对 Pb 的吸附。可乐主要通过形成不溶性 Pb 磷酸盐沉淀来降低 Pb-BA。X 射线衍射和 MINTEQ 模型分析表明，随着可乐或菠菜的摄入，溶解态 Pb 转化为沉淀态或被吸附态 Pb。本研究结果表明，饮食习惯极大地影响了胃肠道中 Pb 的形态和随后的 Pb-BA，这应纳入 Pb 污染土壤的人体健康风险评估中。
