title: Development and application of an inhalation bioaccessibility method (IBM) for lead in the PM10 size fraction of soil.
abstract: 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.
authors.affiliation: Engineering and Environment, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
authors.forename: Ndokiari
authors.initials: N
authors.lastname: Boisa
authors.affiliation: Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
authors.forename: Nwabueze
authors.initials: N
authors.lastname: Elom
authors.affiliation: Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
authors.forename: John R
authors.initials: JR
authors.lastname: Dean
authors.affiliation: Engineering and Environment, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Deary
authors.affiliation: School of Environment, Natural Resources and Geography, Bangor University, Bangor, Gwynedd, LL57 2UW, UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Bird
authors.affiliation: Engineering and Environment, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK. Electronic address: jane.entwistle@northumbria.ac.uk.
authors.forename: Jane A
authors.initials: JA
authors.lastname: Entwistle
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D004391:Dust / Q000032:analysis; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D063826:Kosovo; D007854:Lead / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008962:Models, Theoretical; D052638:Particulate Matter / Q000032:analysis* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D055815:Young Adult
chemical_list: D004391:Dust; D052638:Particulate Matter; D012987:Soil; D012989:Soil Pollutants; D007854:Lead
keywords: Human health; Inhalation bioaccessibility; Lead; PM(10); Soils