贵阳建筑灰尘重金属的生物可给性及其对人体的健康风险评估

摘要

To study the bioaccessibility of heavy metals in constructive dust and their influencing factors, and to assess health risk of hand-to-mouth exposure to heavy metals, samples were collected from buildings, stairs, gate, inside and outside roads, rest area, office area, metal and wood areas from 4 construction sites. An in vitro digestion model was developed to research dissolved concentration of heavy metals and bioaccessibility in gastric and intestinal stages, and assess their health risk based on these results. Among the areas, great differences exited in dissolved concentration of Cu, Pb, Zn and their bioaccessibility. There was a significant correlationship between dissolved concentration and their total concentration (P<0.05), however, bioaccessibility had no relation to pH, OM and total concentration of constructive dust. Besides, in terms of Cu, Zn, low health risk was shown in all areas, but Pb had different results when health risk assessment was based on the gastric data of children. The samples with high contribution rate (>30%), were found in office area and inside road. When health risk assessment was based on the intestinal data of children, the samples with high contribution rate (>3%), were found in inside road, office area and outside road. There was higher health risk in these areas mentioned above for children. It was obvious that there did not exist health risk in Cu and Zn. But health risk of Pb had great change between different human and areas. Due attention should be paid to the constructive dust with both total concentration and high bioaccessbility of Cu, Pb, Zn, as it might pose health risk to the health of general public.%为了研究城市建筑灰尘重金属的生物可给性及其影响因素,评估人体无意摄入建筑灰尘重金属的健康风险,以贵阳市4个建筑工地的楼内、楼梯、建筑区门口、办公区、休息区、建筑区内道路、建筑区外道路、木材堆放区和金属堆放区为研究区,采用in vitro方法研究了这些区域灰尘在胃和肠阶段Cu、Pb、Zn的溶解态量和生物可给性,并以此为基础进行健康风险评估.结果表明,建筑灰尘中Cu、Pb、Zn的溶解态量和生物可给性在各区域差异很大,3种重金属的生物溶解态量与重金属总量呈显著相关(P<0.05),而生物可给性与灰尘pH和有机质无显著相关关系,其大小与重金属总量的高低也无直接关系.各区域建筑灰尘Cu、Zn对人体健康风险较低,但Pb对儿童存在较高的健康风险.其中,在胃阶段,办公区和建筑区内道路对儿童健康风险的贡献率超过30%;在肠阶段,建筑区内道路、办公区、建筑区外道路对儿童健康风险的贡献率超过3%.只有当3种重金属总量很高且生物可给性也较高时,才会对人体产生较高风险.