添加奶粉对土壤中铬、镍、锰、铜生物可给性的影响

The effect of milk powder on the bioaccessibility of Cr,Ni,Mn,and Cu in contaminated soils

为了探究不同成分的奶粉对土壤中Cr、Ni、Mn、Cu生物可给性的影响,本文通过in vitro实验研究了添加全脂或脱脂奶粉后,胃肠阶段土壤中Cr、Ni、Mn、Cu的生物可给性的变化.结果表明,胃阶段,土壤中Cr、Ni、Mn、Cu的生物可给性分别为3.9%—46.2%、4.5%—64.0%、21.2%—72.5%、4.5%—69.5%;添加奶粉后,4种金属的生物可给性均有升高,是未加奶粉的1.1—1.5倍、1.3—2.2倍、1.1—2.1倍、1.0—3.6倍(全脂奶粉)和1.1—1.4倍、1.4—2.4倍、1.2—2.5倍、1.0—4.2倍(脱脂奶粉).小肠阶段,土壤中Cr、Ni、Cu的生物可给性有一定上升,但Mn的生物可给性相比胃阶段降低了;奶粉的添加使Cr、Ni、Mn、Cu等4种金属的溶出量增加,分别是未添加的1.2—1.3倍、1.3—2.3倍、2.0—4.5倍、1.0—1.5倍(全脂奶粉)和1.1—1.5倍、1.6—2.5倍、2.5—6.9倍、1.2—1.8倍(脱脂奶粉),其中Ni、Mn的生物可给性增加显著,且Ni、Mn的生物可给性的增加率高于胃阶段.由此可见,奶粉的添加,尤其是脱脂奶粉,促进了土壤中Cr、Ni、Mn、Cu的溶出释放,可能增大了其对人体的健康风险.

In vitro experiment was used to determine the bioaccessibility of Cr, Ni, Mn, Cu with different composition of milk powder in the gastric and small intestinal phases. The results showed that in the gastric phase, bioaccessibility of Cr, Ni, Mn, Cu were 3.9%—46.2%, 4.5%—64.0%, 21.2%—72.5%, 4.5%—69.5% for five soils. Bioaccessibility of Cr, Ni, Mn, Cu have rised with addition of milk, is not milk powder 1.1—1.5, 1.3—2.2, 1.1—2.1, 1.0—3.6 times （whole milk powder） and 1.1—1.4, 1.4—2.4, 1.2—2.5, 1.0—4.2 times （skim milk powder）. In the small intestinal phase, bioaccessibility of Cr, Ni, Cu improved in soils, but Mn bioaccessibility reduced compared with that in the gastric phase; Milk powder to add increase the dissolubility of Cr,Ni,Mn,Cu, is not milk powder 1.2—1.3, 1.3—2.3, 2.0—4.5, 1.0—1.5 times （whole milk powder） and 1.1—1.4, 1.6—2.5, 2.5—6.9, 1.2—1.8 times （skim milk powder）. Bioaccessibility of Ni, Mn significantly increased and increase rate of Ni,Mn bioaccessibility is higher than the stomach. Therefore, milk powder addition, especially skim milk powder can increase the bioaccessibility of Cr, Ni, Mn, Cu in soils, may increase the risk to the health of human body.