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Over the last century, the Atacama Desert has been exploited due to the mineral resources in this environment. These anthropogenic effects have primarily been linked to the development of the mining industry, the impact of which remains uncertain. Here, we use high-resolution geochemical characterization and magnetic properties analysis from the sedimentary core of Inka Coya Lake, located in the Atacama Desert, to assess the anthropogenic impact in this metallogenic region. The geochemistry and magnetic properties changed with core depth. Elements, such as Cu, Ni, and Zn, increased during the lake's most recent period. Additionally, an increase in mass magnetic susceptibility (χ) and a decrease in magnetic susceptibility depending on the frequency (χfd%) may be attributed to fine iron oxide grains originating from industrial and urban sources. Moreover, indices of pollution classified the sediment of Inka Coya Lake as slightly polluted and strongly polluted with Ni, and Cu, respectively. This could reflect a period of pollution caused by the increase in the production of copper sulfide. These results highlight the possible impact of mining activities in the hyper-arid core of the Atacama Desert, which affects surrounding areas through dispersive processes, even reaching high altitudes, and provides a scientific basis for the prevention of environmental pollution from mining and the protection of the sediment and water source in the Atacama Desert.

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Xanthates, common mining flotation reagents, strongly bind thiophilic metals such as copper (Cu), lead (Pb), cadmium (Cd), and zinc (Zn) and consequentially change their bioavailability and mobility upon their discharge into the environment. However, accurate quantification of the metal-xanthate complexes has remained elusive. This study develops a novel and robust method that realizes the accurate quantification of the metal-xanthate complexes resulted from single and multiple reactions of three typical xanthates (ethyl, isopropyl, and butyl xanthates) and four thiophilic metals (Cu, Pb, Cd, and Zn) in water samples. This method uses sulfur (S2-) dissociation, followed by tandem solid phase extraction of C18 + PWAX and subsequent LC-MS/MS analysis. It has a wide linearity range (1-1000 µg/L, R2 ≥ 0.995), low method detection limits (0.002-0.036 µg/L), and good recoveries (70.6-107.0 %) at 0.01-10 mg/L of xanthates. Applications of this method showed ubiquitous occurrence of the metal-xanthate complexes as the primary species in flotation wastewaters, which the concentrations were 4.6-28.9-fold higher than those previously determined. It is the first quantitative method established for the analysis of metal-xanthate complexes in water samples, which is of great importance to comprehensively understand the fate and risks of xanthates in the environment.

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Many human activities contaminate terrestrial and aquatic environments with numerous chemical pollutants that not only directly alter the environment but also affect microbial communities in ways that are potentially concerning to human health, such as selecting for the spread of antibiotic-resistance genes (ARGs) through horizontal gene transfer. In the present study, metagenomes available in the public domain from polluted (with antibiotics, with petroleum, with metal mining, or with coal-mining effluents) and unpolluted terrestrial and aquatic environments were compared to examine whether pollution has influenced the abundance and composition of ARGs and mobile elements, with specific focus on IS26 and class 1 integrons (intI1). When aggregated together, polluted environments had a greater relative abundance of ARGs than unpolluted environments and a greater relative abundance of IS26 and intI1. In general, chemical pollution, notably with petroleum, was associated with an increase in the prevalence of ARGs linked to multidrug efflux pumps. Included in the suite of efflux pumps were mexK, mexB, mexF, and mexW that are polyspecific and whose substrate ranges include multiple classes of critically important antibiotics. Also, in some instances, ß-lactam resistance (TEM181 and OXA-541) genes increased, and genes associated with rifampicin resistance (RNA polymerases subunits rpoB and rpoB2) decreased in relative abundance. This meta-analysis suggests that different types of chemical pollution can enrich populations that carry efflux pump systems associated with resistance to multiple classes of medically critical antibiotics.IMPORTANCEThe United Nations has identified chemical pollution as being one of the three greatest threats to environmental health, through which the evolution of antimicrobial resistance, a seminally important public health challenge, may be favored. While this is a very plausible outcome of continued chemical pollution, there is little evidence or research evaluating this risk. The objective of the present study was to examine existing metagenomes from chemically polluted environments and evaluate whether there is evidence that pollution increases the relative abundance of genes and mobile genetic elements that are associated with antibiotic resistance. The key finding is that for some types of pollution, particularly in environments exposed to petroleum, efflux pumps are enriched, and these efflux pumps can confer resistance to multiple classes of medically important antibiotics that are typically associated with Pseudomonas spp. or other Gram-negative bacteria. This finding makes clear the need for more investigation on the impact of chemical pollution on the environmental reservoir of ARGs and their association with mobile genetic elements that can contribute to horizontal gene transfer events.

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The adverse impacts of mining industries on human health, local biodiversity, and food security are well-documented in the Katangese Copperbelt. However, farmers' perceptions of pollution and their struggles to obtain compensation for the externalities of mining industries are little addressed in scientific and public debates. Drawing on interviews with smallholder farmers, local civil society archives, oral histories, and analysis of satellite images, this article presents a case of farmers of Mulungwishi Valley whose fields and waterways were polluted by mining effluents. While 25% of respondent farmers argued that they had noticed pollution from the beginning of the 2000s, testimonies from civil society, customary authorities, and farmers concurred that the phenomenon has increased since 2010. Particularly between 2013 and 2014, the death of fish in the Mulungwishi River, the coloration of the water, the spread of mining effluents across the valley, and crop failure raised concerns and despair among farmers. Remarkable changes in land cover and use were noticeable. Since a joint impact assessment in 2014 by la Générale des Carrières et des Mines' (Gécamines) experts and farmers, civil society unsuccessfully continued a struggle to obtain compensation for about 2570 farmers affected by pollution. Despite an absolute silence of the polluter, 88% of these farmers insisted on the depollution of the valley and were willing to accept, if it was offered, financial compensation of $US 2820 per farmer. The decade-long persistence of farmers in asserting these requests debunks the view of farmers as passive or not concerned about environmental pollution. This article will be helpful for stakeholders (victims and polluters) to find common ground when resolving this environmental issue that has resulted in socio-economic difficulties beyond the valley.

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Coeur d'Alene Lake (the Lake) has received significant contamination from legacy mining. Aquatic macrophytes provide important ecosystem services, such as food or habitat, but also have the ability to accumulate contaminants. We examined contaminants (arsenic, cadmium, copper, lead, and zinc) and other analytes (e.g., iron, phosphorus, and total Kjeldahl nitrogen (TKN)) in macrophytes from the Lake. Macrophytes were collected in the Lake from the uncontaminated southern end to the outlet of the Coeur d'Alene River (main contaminant source) located northward and mid lake. Most analytes showed significant north to south trends (Kendall's tau p ≤ 0.015). Concentrations of cadmium (18.2 ± 12.1), copper (13.0 ± 6.6), lead (195 ± 193), and zinc (1128 ± 523) were highest in macrophytes near the Coeur d'Alene River outlet (mean ± standard deviation in mg/kg dry biomass). Conversely, aluminum, iron, phosphorus, and TKN were highest in macrophytes from the south, potentially related to the Lake's trophic gradient. Generalized additive modelling confirmed latitudinal trends, but revealed that longitude and depth were also important predictors of analyte concentration (40-95% deviance explained for contaminants). We used sediment and soil screening benchmarks to calculate toxicity quotients. Quotients were used to assess potential toxicity to macrophyte associated biota and delineate where macrophyte concentrations exceeded local background concentrations. Exceedances (toxicity quotient > one) of background levels by macrophyte concentrations were highest for zinc (86%), followed by cadmium (84%), lead (23%), and arsenic (5%).

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This study evaluates for the first time the impact of a large wildfire on the hydrogeochemistry of a deeply AMD-affected river at the beginning of the wet season. To accomplish this, a high-resolution water monitoring campaign was performed within the basin coinciding with the first rainfalls after summer. Unlike similar events recorded in AMD-affected areas, where dramatic increases in most dissolved element concentrations, and decreases in pH values are observed as a result of evaporitic salts flushing and the transport of sulfide oxidation products from mine sites, a slight increase in pH values (from 2.32 to 2.88) and decrease in element concentrations (e.g.; Fe: 443 to 205 mg/L; Al: 1805 to 1059 mg/L; sulfate: 22.8 to 13.3 g/L) was observed with the first rainfalls after the fire. The washout of wildfire-ash deposited in the riverbanks and the drainage area, constituted by alkaline mineral phases, seems to have counterbalanced the usual behavior and patterns of the river hydrogeochemistry during autumn. Geochemical results indicate that a preferential dissolution occurs during ash washout (K > Ca > Na), with a quick release of K followed by an intense dissolution of Ca and Na. On the other hand, in unburnt zones parameters and concentrations vary to a lesser extent than burnt areas, being the washout of evaporitic salts the dominant process. With subsequent rainfalls ash plays a minor role on the river hydrochemistry. Elemental ratios (Fe/SO4 and Ca/Mg) and geochemical tracers in both ash (K, Ca and Na) and AMD (S) were used to prove the importance of ash washout as the dominant geochemical process during the study period. Geochemical and mineralogical evidences point to intense schwertmannite precipitation as the main driver of reduction in metal pollution. The results of this study shed light on the response of AMD-polluted rivers to certain climate change effects, since climate models predict an increase in the number and intensity of wildfires and torrential rain events, especially in Mediterranean climates.

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Huge volumes of wastewater containing organic flotation reagents such as xanthates have been released into the environment via mining activities, greatly threatening the eco-environment safety. A simple and fast method is urgently needed for accurate analysis of various xanthates in mining and environmental water. Here, a robust method is realized for simultaneous determination of three trace xanthates (i.e., potassium ethyl xanthate, potassium butyl xanthate, and potassium isopropyl xanthate) in environmental water samples, including eutrophic water and flotation wastewater using solid phase extraction (SPE) and HPLC-MS/MS. HPLC-MS/MS parameters, SPE cartridges and eluting solvents, pH values, and SPE procedures were optimized. The new method had an excellent linearity in the range of 1-1000 µg/L (R2 ≥ 0.998), low limits of detection (0.02-0.68 µg/L), and satisfactory accuracy and precision (72.9%-107.6% of average recoveries and <5% of relative standard deviations at 1, 10, 50, and 500 µg/L of xanthates). This is a first method developed for determination of trace xanthates in water samples. It was successfully applied to determine the target analytes in outdated flotation wastewater and river water samples, warranting the occurrence of trace xanthates (0.13-16.9 µg/L) in water and necessity of systematic investigation on environmental fate and risk of xanthates.

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This research reports the effects of pH increase on contaminant mobility in acid mine drainage from the Iberian Pyrite Belt by seawater mixing in the laboratory, simulating the processes occurring in the Estuary of Huelva (SW Iberian Peninsula). Concentrations of Al, Fe, As, Cu and REY in mixing solutions significantly decreased with increasing pH. Schwertmannite precipitation at pH 2.5-4.0 led to the total removal of Fe(III) and As. Subsequently, iron-depleted solutions began to be controlled by precipitation of basaluminite at pH 4.5-6.0, which acted as a sink for Al, Cu and REY. Nevertheless, as the pH rises, schwertmannite becomes unstable and releases back to solution the previously retained As. Moreover, other elements (S, Zn, Cd, Ni and Co) behaved conservatively in mixing solutions with no participation in precipitation processes. Some toxic elements finally end up to the Atlantic Ocean contributing to the total pollutant loads and environmentally threatening the coastal areas.

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Since the middle of the 1500 s, mining has been active in central Mexico. Total estimates for low-grade piles and mine tailing materials in the Guanajuato mining district (GMD) are in the range of 150 million tons, covering an area of 15 to 20 km2. GMD is located in the Guanajuato River sub-basin (GRB), which is part of one of the largest basins in Mexico (Lerma-Santiago). Previous studies on the GRB found unusually high concentrations of heavy metals in mining tailings and sediments. Geochemical and statistical methods were used here to determine the sediment's origin, background values, degree of contamination, and toxicity through different contamination indices. This analysis shows that Cu, Co, As, Sb, and Hg are higher than they are in the upper continental crust (UCC) overbank sediments without human and mining influence, because of the ore deposits and rock weathering in GRB. Geochemistry results in stream sediments show anomalies, where Hg, Cu, Zn, As, and Pb are higher than UCC because those heavy metals and trace elements (HMT) have been influenced by human activities and mineral recovery (smelting, amalgamation, cyanidation). The distribution of high concentrations of HMTs and contamination indices occur in the main channel of the Guanajuato River and downstream of the city of Guanajuato. Statistical analyses (cluster and principal component analysis) reveal relationships between Cr, Ni, Cu, and Pb, which are primarily of natural origin, related to rocks of the upper basin. The middle and lower basins are distinctive in their associations between As, Sb, Zn, Pb, and Hg. Additionally, it is recognized that the origins of Pb, Zn, and Hg are geogenic and anthropogenic. This study demonstrates how crucial it is to understand the geochemistry of various HMT sources, with both natural and anthropogenic contributions (stream sediments and rocks), in order to calculate a more realistic background in a basin with both natural anomalies and anthropogenic contamination. The basin is a regional aquifer recharge area, so the new geochemical data are important for improving basin environmental management.

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A spatially distributed trace metal transport and transformation module was developed and implemented within the hydrological model TOPKAPI-ETH. The new module can be used to better understand, at high spatial and temporal resolution, the transport and reactions of trace metals as they move through a catchment from upland sources to downstream areas and water bodies. The newly developed module takes into consideration solid metal in multiple chemical phases with different reactivity and simulates their mutual transformation over time, which gives the possibility to analyze the fraction of different solid metal phases present in the river suspended sediment. The characteristics and potential of the model are demonstrated by simulating Zinc (Zn) and Cadmium (Cd) dynamics in a headwater catchment of the Xiang River in South China, which has been highly perturbed by mining activities. The developed module is shown to reasonably reproduce the observed dynamics of dissolved and total trace metals flux for 14 months at two monitoring stations. The distributed solute transport model was proved to be capable of explaining the reasons underlying the spatial variability of C-Q relationships that are driven by the combined effect of point and non-point pollution sources, as well as identifying the spatiotemporal hotspots of trace metal pollution. By means of synthetic numerical experiments, a limited impact of slow reactions on dissolved Cd transport from upland to river over short-temporal scales was demonstrated, while for longer scales, e.g. >5 years, this effect becomes more relevant, highlighting potential long-lasting sources of trace metal pollution and their impacts.

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Nitrogen (N) shortage poses a great challenge to the implementation of in situ bioremediation practices in mining-contaminated sites. Diazotrophs can fix atmospheric N2 into a bioavailable form to plants and microorganisms inhabiting adverse habitats. Increasing numbers of studies mainly focused on the diazotrophic communities in the agroecosystems, while those communities in mining areas are still not well understood. This study compared the variations of diazotrophic communities in composition and interactions in the mining areas with different extents of arsenic (As) and antimony (Sb) contamination. As and Sb co-contamination increased alpha diversities and the abundance of nifH encoding the dinitrogenase reductase, while inhibited the diazotrophic interactions and substantially changed the composition of communities. Based on the multiple lines of evidence (e.g., the enrichment analysis of diazotrophs, microbe-microbe network, and random forest regression), six diazotrophs (e.g., Sinorhizobium, Dechloromonas, Trichormus, Herbaspirillum, Desmonostoc, and Klebsiella) were identified as keystone taxa. Environment-microbe network and random forest prediction demonstrated that these keystone taxa were highly correlated with the As and Sb contamination fractions. All these results imply that the above-mentioned diazotrophs may be resistant to metal(loid)s.

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Heavy metal contamination in the soil and the subsequent accumulation in Brachystegia longifolia were investigated as a function of the wind direction and distance from a copper mine in Mufulira, Zambia. Soil and leaves of B. longifolia were collected along transects up to 12 km downwind and 19 km upwind. The total concentration of trace elements in the soil and leaves was determined through pXRF. Plant-available Cu, Fe, Mn, and Zn were extracted in a Mehlich III solution and analyzed using ICP-AES. The degree of soil contamination illustrates that Cu and Fe from the copper mine strongly pollute Mufulira and the surrounding forests. Bioavailable Cu, Fe, Mn, and Zn reduced with increasing distance from the mine. An average of 296 mg/kg Cu, 2337 mg/kg Fe, 1101 mg/kg Mn, and 109 mg/kg Zn were recorded in leaves at the most polluted site. Similarly, 55.21 mg/kg Cu, 516.4 mg/kg Fe, 3196 mg/kg Mn, and 154 mg/kg Zn were recorded at an unpolluted site 19 km upwind. The concentration of Cu and Fe reduced significantly with increasing distance, while Mn and Zn increased significantly. It was further established that B. longifolia leaves accumulated Mn (× 38) and Zn (× 15) more than their respective total concentration in the soil. The concentrations of Cu and Fe found in leaves near the mine, as well as the Mn concentration in leaves across the study sites, could be stressful for B. longifolia tree growth.

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Mining operations are important causes of environmental pollution in developing countries where mining waste management is not adequate. Consequently, heavy metal(loid)s are easily released into the environment, being a potential risk to human health. This study carries out a Bayesian probabilistic human health risk assessment, related to multi-pathway exposure to heavy metal(loid)s in a gold mining area in Southern Ecuador. Concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in tap water, surface water, and soil samples, were analyzed to assess the potential adverse human health effects based on the Hazard Index (HI) and Total cancer risk (TCR). Adults and children residents were surveyed to adjust their exposure parameters to the site-specific conditions. Exposure to heavy metal(loid)s resulted in unacceptable risk levels for human health in the two age groups, both carcinogenic (TCR > 1 × 10-5) and non-carcinogenic (HI > 1) through ingestion of tap water and incidental ingestion of surface water. Sensitivity analysis showed that As concentration in waters and exposure frequency were the main contributors to risk outcome. Exposure to soil via accidental ingestion and dermal contact was below the safety limit, not posing a risk to human health. These findings can provide a baseline for the environmental management of the mining area and indicate the need for further research on As pollution in water and its implications on the health of the inhabitants of mining communities.

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Microorganisms can mediate arsenic (As) and antimony (Sb) transformation and thus change the As and Sb toxicity and mobility. The influence of As and Sb on the innate microbiome has been extensively characterized. However, how microbial metabolic potentials are influenced by the As and Sb co-contamination is still ambiguous. In this study, we selected two contrasting sites located in the Shimen realgar mine, the largest realgar mine in Asia, to explore the adaptability and response of the soil microbiome to As and Sb co-contamination and the impact of co-contamination on microbial metabolic potentials. It is observed that the geochemical parameters, including the As and Sb fractions, were the driving forces that reshaped the community composition and metabolic potentials. Bacteria associated with Bradyrhizobium, Nocardioides, Sphingomonas, Burkholderia, and Streptomyces were predicted to be tolerant to high concentrations of As and Sb. Co-occurrence network analysis revealed that the genes related to C fixation, nitrate/nitrite reduction, N fixation, and sulfate reduction were positively correlated with the As and Sb fractions, suggesting that As and Sb biogeochemical cycling may interact with and benefit from C, N, and S cycling. The results suggest that As and Sb co-contamination not only influences As-related genes, but also influences other genes correlated with microbial C, N, and S cycling.

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Antimony (Sb) and arsenic (As) are toxic elements that occur widely in trace soil concentrations. Expansion of mining activities has increased Sb and As pollution, thus posing a severe threat to human welfare and ecological systems worldwide. Knowledge regarding the composition and adaptation of the microbial communities in these metal(loid) contaminated sites is still limited. In the current study, samples along a river flowing through the world's largest Sb mining area (Xikuangshan) were selected to investigate the microbial response to different Sb or As species. A comprehensive analysis of geochemical parameters, high-throughput sequencing, and statistical methods were applied to reveal the different effects of Sb and As on sedimentary microorganisms. Results suggested that the majority of the Sb and As fractions were not bioavailable. The Sb extractable fraction had a stronger effect on the microbial community compared with its As counterpart. Random forest analyses indicated that the easily exchangeable Sb fraction and specifically sorbed surface-bound fraction were the two most selective variables shaping microbial community diversity. A total of 11 potential keystone phyla, such as bacteria associated with the Bacteroidetes, Proteobacteria, and Firmicutes, were identified according to a molecular ecological network analysis. Strong correlations (|R| > 0.7, P < 0.05) were identified among the indigenous microbial community and pH (negative), sulfate (negative), and exchangeable Sb fraction (positive). Bacteria associated with the genera Geobacter, Phormidium, Ignavibacterium, Desulfobulbus, Ferruginibacter, Fluviicola, Methylotenera, and Scytonema, were predicted to tolerate or metabolize the Sb extractable fraction.

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Heavy metal pollution is widespread in China, particularly in its mining regions. Mercury (Hg) concentrations in birds from Guizhou Province were recently reported to be above adverse effect levels, even in nonmining areas. We sampled birds to investigate whether Hg might be a threat near lead (Pb), zinc (Zn), and tin (Sn) mines in Guangxi Zhuang Autonomous Region. We measured concentrations of 8 metals/metalloids in feathers of 627 resident birds representing 60 species sampled across 14 sites on 5 rivers. We found that Hg concentrations (mean ± standard deviation, 1.27 ± 2.02 ppm) were lower than in the recent Guizhou study. Mercury had the fewest correlations with other metals/metalloids; the mined metals (Pb, Sn, Zn) had the most such correlations. Levels of cadmium (Cd; 1.12 ± 2.64 ppm), arsenic (As; 4.78 ± 17.11 ppm), and Pb (17.18 ± 24.49 ppm) were closer to thresholds of adverse effects or relatively high compared to other studies. With the exception of a few hot spots for Hg, Cd, and As near mines, metal/metalloid levels were fairly evenly distributed among sites, consistent with the regional occurrence of mineable ore deposits. It appears that Hg is not threatening to all avian species in China, although it may be problematic for some species near Hg mines. In addition to Hg, however, other metals/metalloids may pose wildlife health hazards. Environ Toxicol Chem 2020;39:371-380. © 2019 SETAC.

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Drinking water sources used by largely rural and indigenous communities around Lake Poopó in the Bolivian Altiplano are impacted by drought and a combination of natural and anthropogenic mining-related contaminants putting the long-term health and sustainability of these communities at risk. As an alternative drinking water source, 18 rainwater harvesting tanks connected to corrugated iron roofs, each with a first-flush system, were installed in 5 communities around the lake. The water quality of these tanks was monitored over 22 months and compared to alternative unprotected surface and groundwater sources the communities previously relied upon. The rainwater quality was found to be within the Bolivian and World Health Organization (WHO) limits, except for elevated arsenic concentrations two times the recommended health limit (0.01 mg/L). Tracing arsenic concentrations through the rainwater flow-path showed that the elevated arsenic concentrations result from mineral dust particles entering the system when rainwater interacts with the roof catchment, with arsenic leaching out. A leaching test showed that 24 h of contact time between 200 mL of water and <1 g of roof dust is enough to raise the arsenic levels of the water above the Bolivian and WHO limit. Currently, no other research exists evaluating the quality of harvested rainwater in the Bolivian Altiplano for human consumption or the source of arsenic in harvested water. This represents a significant knowledge gap for future development practitioners and programs addressing water security around Lake Poopó and the wider region. As a result, it is strongly recommended to include arsenic as a standard parameter in water quality monitoring of rainwater harvesting projects, especially in active mining regions, and to optimize strategies to minimize roof dust from entering the collection system.

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A field survey was conducted to investigate metal(loid) concentration in soils and native plants in the Baoshan mining area for potential application in phytoremediation. Total concentrations of arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in soil varied from 125 to 6656, 5.10 to 1061, 568 to 49294, and 241 to 17296 mg kg-1, respectively, showing severe contamination. Among 20 species native to this area, Pteris ensiformis accumulated 1091 mg kg-1 As in the shoot, and its translocation factor (TF) was greater than 1, suggesting potential capacity for As phytoextraction. Boehmeria nivea, Aster prorerus, and Hydrocotyle sibthorpioides showed potential for phytoextraction of Cd due to their high accumulation of Cd in shoots (490.3, 175.4, and 128.5 mg kg-1, respectively) and high TFs (92.0, 22.1, and 6.7, respectively). Eleusine indica and P. ensiformis were found to contain high concentrations of Pb (7474 mg kg-1) and Zn (1662 mg kg-1) in roots, but with low TFs for Pb (0.4) and Zn (0.2), suggesting potential capability for phytostabilization. There was a positive correlation (p < 0.01, N = 25) of TFs between the metal(loid)s, indicating a synergic interaction in the uptake of metal(loid)s by these plants. According to metal(loid) concentrations in shoots, bioconcentration factors (BFs), and TFs, as well as the botanical features such as wide occurrence, high biomass yield, and rapid growth of the plants, the five native species identified above have the potential for phytoremediation in the Baoshan mining area.

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Natural levels of heavy metals (HM) have increased during the industrial era to the point of posing a serious threat to the environment. The use of tree species to record contamination is a well-known practice. The objective of the study was to compare HM levels under different pollution conditions: a) soil pollution due to mining waste; b) atmospheric pollution due to coal-fired power plant emissions. We report significant HM enrichment in Pinus halepensis tissues. Near a burning power plant, Pb content in a tree wood was 2.5-fold higher that in natural areas (no pollution; NP). In mining areas, Cd content was 25-fold higher than NP. The hypothesis that HM contents in tree rings should register pollution is debatable. HM uptake by pines from soil, detoxification mechanisms and resuspended local soil dust is involved in HM contents in wood and bark.

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Fourhorn sculpins (Myoxocephalus quadricornis) and shorthorn sculpins (Myoxocephalus scorpius) have been considered suitable local bioindicators for environmental monitoring studies in the Arctic. Because these species share many characteristics, data from the two species have previously been pooled when assessing marine metal contamination. A chemical and histological study was conducted on fourhorn and shorthorn sculpins collected around a contaminated lead-zinc mine at East Greenland to investigate whether there were any differences in the residues of metals, histopathology and parasites in liver and gills between the two sculpin species. The results demonstrated that concentrations of copper (Cu), zinc (Zn), mercury (Hg) and lead (Pb) were significantly higher in the fourhorn sculpins (p<0.001) while there were no significant differences for arsenic (As) or cadmium (Cd). Furthermore, density of blood vessel fibrosis (p=0.028), prevalence and density of chondroplasia (p=0.002 and p=0.005, respectively), number of mucin-containing mucous cells (p<0.001) and chloride cells (p<0.001) and mean intensity of colonial Peritricha (p<0.001) were significantly higher in fourhorn sculpin. Based on these results we suggest that pooling the two species when conducting environmental assessments is not recommended as it can lead to incorrect conclusions. We propose that a larger study investigating the biological effects of zinc-lead mining in Greenland is needed.

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