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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.

The solid state partitioning of metals and As in river channel sediments has been investigated along an 828 km study reach comprising the rivers Lapuş, Someş and Tisa, using a 4-stage sequential extraction procedure (SEP) that identified 4 chemical phases: (1) exchangeable, (2) Fe and Mn oxides, (3) organic matter/sulphides and (4) residual. Peak total concentrations of As (240 mg kg−1), Cd (95 mg kg−1), Cu (24,500 mg kg−1) and Pb (21,100 mg kg−1) were found in the River Lapuş immediately downstream of Băiuţ base-metal mine, with Zn concentrations (23,000 mg kg−1) peaking 2 km further downstream. Contaminant metals and As within samples close to Băiuţ mine were largely bound to sulphides (>92%). Ten km downstream from Băiuţ mine, however, Cd and Zn were found to be environmentally significant due to their strong association with the exchangeable phase (73 and 47%, respectively). Lead was found to be predominantly associated with Fe and Mn oxides (71%), but concentrations in the residual phase were relatively high in the upper Tisa. Copper was more evenly distributed between the 4 phases than the other 4 elements analysed. Elevated metal and As concentrations were found in the rivers Lapuş and Someş downstream of polluted tributaries, but sites on the River Tisa had total metal concentrations below Dutch guideline values. The implications of the river sediment metal partitioning results on the environment are considered in light of Cd and Zn ‘exchangeable hotspots’ at sites on the Lapuş and Someş Rivers

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Results from the analysis of aqueous and solid-phase V speciation within samples collected from the Hazeltine Creek catchment affected by the August 2014 Mount Polley mine tailings dam failure in British Columbia, Canada, are presented. Electron microprobe and X-ray absorption near-edge structure (XANES) analysis found that V is present as V3+ substituted into magnetite and V3+ and V4+ substituted into titanite, both of which occur in the spilled Mount Polley tailings. Secondary Fe oxyhydroxides forming in inflow waters and on creek beds have V K-edge XANES spectra exhibiting E1/2 positions and pre-edge features consistent with the presence of V5+ species, suggesting sorption of this species on these secondary phases. PHREEQC modeling suggests that the stream waters mostly contain V5+ and the inflow and pore waters contain a mixture of V3+ and V5+. These data, and stream, inflow, and pore water chemical data, suggest that dissolution of V­(III)-bearing magnetite, V­(III)- and V­(IV)-bearing titanite, V­(V)-bearing Fe­(-Al-Si-Mn) oxhydroxides, and V-bearing Al­(OH)3 and/or clay minerals may have occurred. In the circumneutral pH environment of Hazeltine Creek, elevated V concentrations are likely naturally attenuated by formation of V­(V)-bearing secondary Fe oxyhydroxide, Al­(OH)3, or clay mineral colloids, suggesting that the V is not bioavailable. A conceptual model describing the origin and fate of V in Hazeltine Creek that is applicable to other river systems is presented.