title: Effect of weathering product assemblages on Pb bioaccessibility in mine waste: implications for risk management.
abstract: General assessments of orebody types and associated mine wastes with regard to their environmental signature and human health hazards are needed to help in managing present and historical mine waste facilities. Bioaccessibility tests and mineralogical analysis were carried out on mine waste from a systematic sampling of mine sites from the Central Wales orefield, UK. The bioaccessible Pb widely ranged from 270 to 20,300 mg/kg (mean 7,250 mg/kg, median 4,890 mg/kg), and the bioaccessible fraction from 4.53 to >100% (mean 33.2%, median 32.2%), with significant (p=0.001) differences among the mine sites. This implies sensitivity of bioaccessibility to site-specific conditions and suggests caution in the use of models to assess human health impacts generalised on the basis of the mineral deposit type. Mineralogical similarities of the oxidation products of primary galena provided a better control over the observed Pb bioaccessibility range. The higher Pb bioaccessibility (%) was related to samples containing cerussite, irrespective of the presence of other Pb minerals in the mineral assemblage; lower Pb bioaccessibility resulted where anglesite was the main Pb mineral phase and cerussite was absent. A solubility diagram for the various Pb minerals in the waste was derived using PHREEQC model, and the experimental Pb concentrations, measured in the simulated gastric solution, were compared with the equilibrium modelling results. For samples containing cerussite, the model well predicted the soluble Pb concentrations measured in the gastric solution, indicative of the carbonate mineral phase control on the Pb in solution for these samples and little kinetic control on the dissolution of cerussite. On the contrary, most mine waste samples containing dominant anglesite and or plumbojarosite (no cerussite) had lower solution Pb values, falling at or below the anglesite and plumbojarosite solubility equilibrium concentrations, implying kinetic or textural factors hindering the dissolution.
authors: British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK, bpal@bgs.ac.uk.
authors: Barbara
authors: B
authors: Palumbo-Roe
authors: Joanna
authors: J
authors: Wragg
authors: Mark R
authors: MR
authors: Cave
authors: Doris
authors: D
authors: Wagner
mesh_terms: D002254:Carbonates / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data; D006801:Humans; D007220:Industrial Waste / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D008906:Mining; D012308:Risk Management; D012989:Soil Pollutants / Q000032:analysis*; D013440:Sulfides / Q000032:analysis; D014852:Wales; D014887:Weather
chemical_list: D002254:Carbonates; D007220:Industrial Waste; D012989:Soil Pollutants; D013440:Sulfides; C018391:lead sulfide; D007854:Lead; C043262:lead carbonate
references: Regul Toxicol Pharmacol. 1990 Apr;11(2):158-90
references: 2185511
references: J Hazard Mater. 2010 Oct 15;182(1-3):656-64
references: 20663608
references: J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Jul 15;42(9):1303-15
references: 17654150
references: Med J Aust. 1981 Sep 5;2(5):232-4
references: 7300741
references: Environ Geochem Health. 1991 Jun;13(2):127-35
references: 24202846
references: Environ Pollut. 2012 Dec;171:265-72
references: 22938825
references: Sci Total Environ. 2011 Sep 1;409(19):4016-30
references: 21703664
references: Environ Sci Technol. 2002 Aug 1;36(15):3326-34
references: 12188361
references: J Environ Monit. 2008 Dec;10(12):1448-53
references: 19037486
references: J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Jul 15;42(9):1203-11
references: 17654140
references: Environ Geochem Health. 2005 Apr;27(2):121-30
references: 16003580
references: Sci Total Environ. 2007 Mar 1;374(1):91-101
references: 17257653
references: Environ Sci Technol. 2008 Feb 1;42(3):779-85
references: 18323102
references: J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Jul 15;42(9):1223-31
references: 17654142
references: Environ Sci Technol. 2012 Jun 5;46(11):6252-60
references: 22606949
references: Sci Total Environ. 2011 Nov 1;409(23):4958-65
references: 21930292
references: Chemosphere. 2012 Feb;86(5):460-7
references: 22024094