小白菜的干鲜状态对其铅的生物可给性的影响(Effects of Dry and Fresh States of Brassica chinensis on the Oral Bioaccessibility of Lead)

为了研究小白菜的干鲜状态对其铅的生物可给性的影响,设置了对照(不添加铅,本底值为32.37mg·kg-1)、300mg·kg-1和500mg·kg-13种土壤铅浓度处理的盆栽实验,并将收获的小白菜分别以干样和鲜样进行基于生理学的invitro人工胃肠模拟实验,测定其中铅的生物可给性.结果表明:栽种2个月后,小白菜铅含量分别达到0.38mg·kg-1、4.55mg·kg-1和12.50mg·kg-1(干重),对铅的富集系数分别为0.012、0.015和0.025,可能存在较高的健康风险.invitro实验表明:样品干鲜状态、铅浓度处理以及二者的交互效应是影响铅的生物可给性的重要因素.无论干样还是鲜样,铅在胃阶段和小肠阶段的溶解态量均随样品铅含量的增加而线性增加;对于同一铅浓度处理,鲜样中铅的生物可给性无论在胃阶段还是小肠阶段均显著高于干样(p<0.01).使用干样进行健康风险评价可能会低估小白菜中的铅对人体的健康风险.

Effects of Dry and Fresh States of Brassica chinensis on the Oral Bioaccessibility of Lead

In order to study the effects of dry and fresh states of Brassica chinensis on the oral bioaccessibility of Pb, a pot experiment with three soil Pb concentration treatments was conducted, including control (without Pb addition, background value was 32.37mg·kg-1), 300mg·kg-1 and 500mg·kg-1. Then the dry and fresh samples were digested respectively using a physiologically based in vitro test, and the bioaccessibility of Pb was measured. Results showed that Brassica chinensis might pose great health risk of Pb. Its total Pb concentrations under three treatments were 0.38mg·kg-1, 4.55mg·kg-1, and 12.50mg·kg-1(dry weight), and Bioconcentration Factors(BCFs)of Pb were 0.012, 0.015, and 0.025, respectively. In vitro test indicated that the main influencing factors on the oral bioaccessibility of Pb were the dry and fresh states, soil Pb concentration, and their interaction effect. For both dry and fresh states, the soluble Pb concentrations in gastric and intestinal phases rose linearly with the increase of the total Pb concentration of the sample. For both gastric and intestinal phases, the bioaccessibility of Pb in fresh sample was significantly higher than that in dry sample (p<0.01). The human health risk of Pb in Brassica chinensis could be underestimated if dry sample was adopted.