Engineering and Environment, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
Environ Int. 2014 Sep;70:132-42. doi: 10.1016/j.envint.2014.05.021. Epub 2014 Jun 14.
An approach for assessing the inhalation bioaccessibility of Pb in the PM10 size fraction is presented, using an in vitro simulated epithelial lung fluid to represent the extracellular environment of the lung. The developed inhalation bioaccessibility method (IBM) is applied to a range of urban surface soils and mining wastes obtained from Mitrovica, Kosovo, a site where impacts upon human health following exposure to Pb have been internationally publicised. All Pb determinations were undertaken by inductively coupled plasma mass spectrometry (ICP-MS). The pseudo-total concentration of Pb (microwave acid digestion using aqua-regia) varied between matrices: smelter (20,900-72,800mgkg(-1)), topsoil (274-13,700mgkg(-1)), and tailings (2990mgkg(-1)-25,300mgkg(-1)). The in vitro inhalation bioaccessibility was typically several orders of magnitude lower: smelter (7.0-965mgkg(-1)), topsoil (9.8-1060mgkg(-1)), and tailings (0.7mgkg(-1)-49.2mgkg(-1)). The % inhalation bioaccessibility ranged from 0.02 to 11.0%, with the higher inhalation bioaccessible Pb concentrations being observed for samples from the Bosniak Mahalla area of Mitrovica (an area proposed for the relocation of internally displaced peoples). The estimated inhalation dose (for adults) calculated from the PM10 pseudo-total Pb concentration ranged from 0.369 to 1.284μgkg(-1)BWday(-1) (smelter), 0.005-0.242μgkg(-1)BWday(-1) (topsoil), and 0.053-0.446μgkg(-1)BWday(-1) (tailings). When daily inhalation doses were calculated using the bioaccessible Pb concentration the modelled exposure doses were much lower: smelter (0.0001-0.0170μgkg(-1)BWday(-1)), topsoil (0.0002-0.0187μgkg(-1)BWday(-1)) and tailings (0.0001-0.0009μgkg(-1)BWday(-1)). Modelled for the neutral pH conditions of the interstitial lung environment, the results indicate a low potential inhalation bioaccessibility for Pb in these samples. Given the already elevated environmental Pb burden experienced by the local population, where significant prolonged dust or particulate generating activities are taking place, or where the inhaled particles are phagocytized, then inhalation exposure has the potential to significantly add to the overall Pb burden. Such data are important for local policy makers to better enable them to assess risk, especially in areas where soils/dusts have elevated levels of contamination.
提出了一种评估 PM10 粒径中 Pb 吸入生物可给性的方法，该方法使用体外模拟的肺上皮液来代表肺的细胞外环境。所开发的吸入生物可给性方法 (IBM) 应用于一系列从科索沃米特罗维察获得的城市表层土壤和采矿废物，该地区 Pb 暴露对人体健康的影响已在国际上公布。所有 Pb 测定均采用电感耦合等离子体质谱法 (ICP-MS) 进行。Pb 的假总量浓度（使用王水进行微波酸消解）在基质之间变化：冶炼厂（20900-72800mgkg(-1))、表土（274-13700mgkg(-1)) 和尾矿（2990mgkg(-1)-25300mgkg(-1))。体外吸入生物可给性通常要低几个数量级：冶炼厂（7.0-965mgkg(-1))、表土（9.8-1060mgkg(-1)) 和尾矿（0.7mgkg(-1)-49.2mgkg(-1))。吸入生物可给性的百分比范围为 0.02-11.0%，来自米特罗维察博斯尼亚马哈拉地区的样本观察到较高的吸入生物可给性 Pb 浓度（拟议为境内流离失所者重新安置的地区）。根据 PM10 假总 Pb 浓度计算的估计吸入剂量（成人）范围为 0.369-1.284μgkg(-1)BWday(-1)（冶炼厂）、0.005-0.242μgkg(-1)BWday(-1)（表土）和 0.053-0.446μgkg(-1)BWday(-1)（尾矿）。当使用生物可给性 Pb 浓度计算每日吸入剂量时，模型暴露剂量要低得多：冶炼厂（0.0001-0.0170μgkg(-1)BWday(-1)）、表土（0.0002-0.0187μgkg(-1)BWday(-1)）和尾矿（0.0001-0.0009μgkg(-1)BWday(-1)）。在肺间质环境的中性 pH 条件下建模，结果表明这些样本中 Pb 的吸入生物可给性较低。鉴于当地居民已经经历了环境 Pb 负担的增加，在那里进行了大量持续的粉尘或颗粒生成活动，或者吸入的颗粒被吞噬，那么吸入暴露有可能显著增加总体 Pb 负担。这些数据对于地方决策者非常重要，使他们能够更好地评估风险，特别是在土壤/灰尘污染水平较高的地区。
