Effect of weathering product assemblages on Pb bioaccessibility in mine waste: implications for risk management

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.     

Optimized yeast-based in vitro bioassay for determination of estrogenic and androgenic activity of hydroxylated / methoxylated metabolites of BDEs / CBs and related lipophilic organic pollutants

ABSTRACT

Persistent organic pollutants (POPs) are known to show endocrine disrupting (ED) activity, including interactions with hormone receptors. The aim of this work was to develop a bioassay applicable for evaluation of ED potency of highly lipophilic metabolites of POPs. To that end, a yeast-based bio-assay protocol was used. Estrogenic / androgenic activity of some native brominated biphenyl ethers (BDEs) / chlorinated biphenyls (CBs), and their hydroxylated / methoxylated metabolites was assessed. Since data (including potency compared to reference native hormones) obtained using different protocols vary, the possibility that yeast transforms POPs into some more potent compounds was first checked; it seems that no such transformation is important from the test applicability standpoint. The developed method was sensitive with EC50 values 6.5*10^?11 M and 4.5*10^?9 M calculated for E2 and DHT, respectively. Both CBs and BDEs show weak estrogenic activity negatively correlated with the degree of their halogenation, but their metabolites are significantly more potent xenohormones. 4-OH-2,2′,4′,6′-TeCB was the most potent estrogen receptor (ER) agonist among all tested compounds; its activity was only 1,000 times lower than that of native E2.     

Environmental impact of flood: the study of arsenic speciation in exchangeable fraction of flood deposits of Warta river (Poland) in determination of "finger prints" of the pollutants origin and the ways of the migration

The paper presents the application of the hyphenated technique - high-performance liquid chromatography with atomic absorption spectrometry detection with hydride generation (HPLC-HG-AAS) - in the determinations of inorganic forms of arsenic: As(III) and As(V) in the exchangeable fraction of flood deposits. The separation of analytical signals of the determined arsenic forms was obtained using an ion-exchange column in a chromatographic system with the atomic absorption spectrometer as a detector, at the determination limits of 5 ng g⁻¹ for As(III) and 10 ng g⁻¹ for As(V). Flood deposits were collected after big flood event in valley of the Warta river which took place in summer 2010. Samples of overbank deposits were taken in Poznań agglomeration and vicinity (NW Poland). The results of determinations of arsenic forms in the exchangeable fraction of flood deposits allowed indication of a hypothetical path of deposits migration transported by a river during flood and environmental threats posed by their deposition by flood.     

Mean annual (222)Rn concentration in homes located in different geological regions of Poland: first approach to whole country area

The paper presents the results of year-long measurements of radon (²²²Rn) concentration inside 129 buildings in Poland in relation to the geological conditions of their foundation. The authors took into account the division of the country into tectonic units, as well as the lithology of the rocks forming the bedrock of these buildings. As expected, the highest value of mean annual ²²²Rn concentration (845 Bq/m³) was recorded in a building situated in the area of the Sudetes, while the highest geometric mean (characteristic of the expected log-normal data distribution) was calculated based on measurements from buildings located within the East-European craton, in the area of Mazury-Podlasie monocline, where it reached 231 Bq/m³. Such results reflect geological conditions - the occurrence of crystalline rocks (especially U- and Ra-enriched granites and orthogneisses) on the surface in the Sudetes, and of young post-glacial sediments containing fragments of Scandinavian crystalline rocks, also enriched with U and Ra, in the area of Mazury-Podlasie monocline. However, the least expected result of the investigations was finding out that, contrary to the hitherto widespread belief, none of the major tectonic units of Poland can be excluded from the list of those containing buildings with mean annual ²²²Rn concentration exceeding 200 Bq/m³. The mean annual concentration of radon for all the buildings were much higher than the mean concentration value (49.1 Bq/m³) of indoor radon in Poland quoted so far. These results cast a completely new light on the necessity to perform measurements of radon concentration in residential buildings in Poland, no more with reference to small areas with outcrops of crystalline rocks (especially the Sudetes, being the Polish fragment of the European Variscan belt), but for all the major tectonic units within Poland.     

Spatiotemporal dynamics of spring and stream water chemistry in a high-mountain area

The present study deals with the application of the self-organizing map (SOM) technique in the exploration of spatiotemporal dynamics of spring and stream water samples collected in the Chocho?owski Stream Basin located in the Tatra Mountains (Poland). The SOM-based classification helped to uncover relationships between physical and chemical parameters of water samples and factors determining the quality of water in the studied high-mountain area. In the upper part of the Chocho?owski Stream Basin, located on the top of the crystalline core of the Tatras, concentrations of the majority of ionic substances were the lowest due to limited leaching. Significantly higher concentration of ionic substances was detected in spring and stream samples draining sedimentary rocks. The influence of karst-type springs on the quality of stream water was also demonstrated.     

A comparative study of the performance of passive samplers

Atmospheric concentrations of benzene, toluene, ethylbenzene, and xylenes (o-xylene and m,p-xylene) were assessed in the Tricity area (Gdańsk-Sopot-Gdynia, Poland) with the use of two types of passive samplers: permeation (homemade passive samplers) and diffusive (Radiello and Orsa 5). Samples were collected during 2008 at selected sites in the Tricity area at monitoring stations belonging to the agency of Regional Air Quality Monitoring Foundation. The field study was conducted to compare the performance of these two different types of passive samplers. A statistical approach was formulated, and the experimental data were evaluated using the paired t test, Wilcoxon signed rank-sum test, and Friedman analysis of variance. All the statistical results confirm the hypothesis that the differences between the performances of the three sampling devices are highly significant. Despite the fact that data obtained with the homemade passive sampler indicated that the results were higher compared with those for the Radiello and Orsa 5 diffusive samplers, the authors note that all differences between the homemade permeation sampler and the Radiello and Orsa 5 diffusive samplers are positive.     

Characterization of bacterial communities at heavy-metal-contaminated sites

The microbial community in soil samples from two long-term contaminated sites was characterized by using culture-dependent and culture-independent methods. The two sites investigated contained high amounts of heavy metals and were located in the upper Silesia Industrial Region in southern Poland. The evaluation of the aerobic soil microbial population clearly demonstrated the presence of considerable numbers of viable, culturable bacteria at both sites. A high fraction of the bacterial population was able to grow in the presence of high amounts of metals, i.e. up to 10 mM Zn²⁺, 3 mM Pb²⁺ or 1 mM Cu²⁺. Site 1 contained significantly (P < 0.05) lower bacterial numbers growing in the presence of 10 mM Zn²⁺ than site 2, while the opposite was observed for bacteria tolerating 1 mM Cu²⁺. This coincided with the contents of these two metals at the two sites. Ecophysiological (EP) indices for copiotrophs (r-strategists) and oligotrophs (K-strategists) pointed to high bacterial diversity at both sites. Fluorescence in situ hybridization (FISH) analysis indicated that Actinobacteria and Proteobacteria represent the physiologically active fraction of bacteria at the two sites. Shannon diversity (H′) indices for FISH-detected bacterial phylogenetic groups were not significantly different at the two sites.     

Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits "The Gully" a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997.     

Degradation of hop bitter acids by fungi

Nine fungal strains related to: Trametes versicolor, Nigrospora oryzae, Inonotus radiatus, Crumenulopsis sororia, Coryneum betulinum, Cryptosporiopsis radicicola, Fusarium equiseti, Rhodotorula glutinis and Candida parapsilosis were tested for their ability to degrade humulones and lupulones. The best results were obtained for T. versicolor culture, in which humulones and lupulones were fully degraded after 4days of incubation in the dark or after 36h in the light. The experiments were performed on a commercial hop extract and on sterilized spent hops.     

Microbially mediated cadmium sorption/desorption processes in soil amended with sewage sludge

A multi-compartment system was used to study the importance of microorganisms for Cd desorption from soil amended with sewage sludge and simultaneous resorption of the mobilized metal by soil constituents. Using this system made it possible to study the participation of microorganisms (Arthrobacter, Trichoderma), montmorillonite, humic acids, and iron oxides in resorption of the released Cd. A filter-sterilized water extract of root-free soil of pH 6.7 (RF) or RF supplemented with glucose (RFG) were used to mobilize Cd from soil at 14 degrees C in 48 h. Cadmium found in those extracts after 48-h incubation was recognized as bioavailable. Changes in pH values and enrichment of soil extracts with organic acids and siderophores resulted from microbial growth. RFG with lower pH and a higher content of ligands mobilized, on average, 40% of Cd introduced with sewage sludge amended soil, whereas RF mobilized only 20% of it. Sequential extractions of Cd at time 0 and Cd remaining in soil showed that RFG had mobilized Cd mostly from the fraction bound with Fe and Mn oxides. Microbial biomass accounted for only up to 3.4% (w/w) of the soil constituents used in the experiments but resorbed 25% of mobilized Cd. The chemical composition of mobilizing soil extracts and the solid-to-mobilizing-extracts volume ratio had a significant effect on the amount of bioavailable Cd. The results of the study suggest that microbial metabolites were involved in Cd mobilization, while the biomass of microorganisms was involved in Cd resorption as a biosorbent.