Model human digestive system for the determination of bioaccessibility of environmental pollutants.

该项目将使用一个强大的基于实验室的胃肠道模型来确定环境污染物在人体肠道中的生物适应性(污染物在肠道内被吸收并与人体细胞相互作用的能力)。这将大大提高监管当局为确定污染物的毒理学及其在人类摄入时的影响而进行的风险评估过程的准确性。当能够准确确定这一参数时，环境署在法规指南中提供的土壤指标值(SGV)将显著提高，并用于评估受污染的土地。目前，还没有这种可重复的测定方案，指导值是基于摄入量，即个人接触的物质的量，而不是摄取量，即进入人体并被血流摄取的污染物的量。这项提议将两个既定的GUT模型结合在一起。BGS模型反映了胃和小肠的行为，雷丁大学的模型模拟了结肠。上部肠道的酸性条件被认为是从土壤基质中释放金属的主要场所，而结肠的大量微生物活动可能对有机污染物有更大的影响。这两类污染物都将在提案中进行测试。这两个模型的统一将带来镜像整个人类消化道的能力。该提议得到了卫生保护局的支持，该机构在生产SGV时向环境署提供毒理学支持。HPA将为整个项目进行的毒理学分析提供支持和建议。

This project will use a robust laboratory based model of the gastrointestinal tract to determine the bioacessibility (ability of a pollutant to be absorbed within the gut and interact with human cells) of environmental pollutants in the human gut. This will provide a major advance in accuracy of the risk assessment process undertaken by regulatory authorities to determine the toxicology of pollutants and their effects when ingested by humans. When accurate determinations of this parameter can be made, the soil guideline values (SGVs) provided by the Environment Agency in the regulatory guidance and for the assessment of contaminated land, will be significantly enhanced. Currently, no such repeatable determination protocol exists and guidance values are based upon intake, i.e. the amount of substance to which an individual is exposed rather than uptake, the amount of contaminant which enters the body and is taken up by the bloodstream. This proposal brings together two established gut models. The BGS model which mirrors behaviour in the stomach and small intestine and the University of Reading model which simulates the colon. The acidic conditions of the upper gut are believed to be the primary site of release of metals from the soil matrix, whereas the profuse microbial action of the colon may have more of an effect on organic pollutants. Both pollutant classes will be tested in the proposal. Unification of the two models will bring about the ability to mirror the whole human digestive tract. The proposal is supported by the Health Protection Agency who provide toxicological support to the Environment Agency when deriving SGVs. The HPA will support and advise on toxicological analyses conducted throughout this project.