Colon Extended Physiologically Based Extraction Test (CE-PBET) Increases Bioaccessibility of Soil-Bound PAH
Colon Extended Physiologically Based Extraction Test (CE-PBET) Increases Bioaccessibility of Soil-Bound PAH
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DOI：
10.1021/es2004705
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发表时间：
2011-06-15
影响因子：
11.4
通讯作者：
Collins, C. D.
中科院分区：
文献类型：
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作者：
Tilston, E. L.;Gibson, G. R.;Collins, C. D.
如果依赖污染物的总浓度来评估受污染土地对人类健康构成的风险，可能会严重高估。体外浸提试验，如生理学浸提试验（PBET），模拟人体胃肠道的物理化学条件，为常规试验目的提供了更实用的替代方案。然而，尽管通过结肠的时间占通过人消化道的时间的约80%，并且体内结肠的典型内容物是具有促进有机污染物解吸的潜力的富含碳水化合物的水性介质，但PBET仅包括胃和小肠隔室。通过添加一个8小时的结肠隔室4 PBET和使用的碳水化合物丰富的补料状态介质，我们证明，结肠延长PBET（CE-PBET）增加评估土壤结合PAR的生物可及性高达50%，在实验室土壤和4个因素，在田间土壤。我们将这种增加的生物可及性归因于额外的提取时间和结肠隔室中碳水化合物的存在的组合，这两者都有利于PAR从土壤中解吸。我们建议，未来的评估土壤中的有机污染物的生物可及性，使用生理为基础的提取试验应该有一个结肠车厢CE-PBET。
Assessment of the risk to human health posed by contaminated land may be seriously overestimated if reliant on total pollutant concentration. In vitro extraction tests, such as the physiologically based extraction test (PBET), imitate the physicochemical conditions of the human gastro-intestinal tract and offer a more practicable alternative for routine testing purposes. However, even though passage through the colon accounts for approximately 80% of the transit time through the human digestive tract and the typical contents of the colon in vivo are a carbohydrate-rich aqueous medium with the potential to promote desorption of organic pollutants, PBET comprises stomach and small intestine compartments only. Through addition of an eight-hour colon compartment to 4 PBET and use of a carbohydrate-rich fed-state medium we demonstrated that colon-extended PBET (CE-PBET) increased assessments of soil-bound PAR bioaccessibility by up to 50% in laboratory soils and a factor of 4 in field soils. We attribute this increased bioaccessibility to a combination of the additional extraction time and the presence of carbohydrates in the colon compartment, both of which favor PAR desorption from soil. We propose that future assessments of the bioaccessibility of organic pollutants in soils using physiologically based extraction tests should have a colon compartment as in CE-PBET.