Metal exposure and effects in voles and small birds near a mining haul road in Cape Krusenstern National Monument, Alaska

A Global Systematic Review of Lead (Pb) Exposure and its Health Effects in Wild Mammals

Lead (Pb) is a toxic nonessential metal, known mainly for causing poisoning of humans and wild birds. However, little is known about Pb exposure and its associated health effects in wild mammals. We conducted a global systematic literature review to identify peer-reviewed studies published on Pb exposure in wild mammalian species and the health effects they identified. In total, 183 studies, conducted in 35 countries and published over 62 yr (1961-2022), were included in the review. Only 6% (11/183) of the studies were conducted in developing countries. Although 153 mammalian species were studied, most studies focused on species that are easy to access (i.e., hunted species and small mammals that are easy to trap). Therefore, carnivores and scavengers were less frequently studied than herbivores and omnivores. Despite all studies reporting Pb concentrations, only 45 (25%) studies investigated health effects and, of these 45 studies, only 28 (62%) found any health effect in 57 species. All health effects were negative and ranged from subclinical effects to fatality. Methodologies of Pb sampling and quantification and reporting of results varied widely across the studies, making both Pb concentrations and health effects difficult to compare and evaluate. Thus, there is a need for more research on Pb exposure and its health effects on wild mammals, especially as carnivores and scavengers could be used as sentinels for ecosystem health.

Mercury-Modulated Immune Responses in Arctic Barnacle Goslings (Branta leucopsis) upon a Viral-Like Immune Challenge

Historical mining activities in Svalbard (79°N/12°E) have caused local mercury (Hg) contamination. To address the potential immunomodulatory effects of environmental Hg on Arctic organisms, we collected newborn barnacle goslings (Branta leucopsis) and herded them in either a control or mining site, differing in Hg levels. An additional group at the mining site was exposed to extra inorganic Hg(II) via supplementary feed. Hepatic total Hg concentrations differed significantly between the control (0.011 ± 0.002 mg/kg dw), mine (0.043 ± 0.011 mg/kg dw), and supplementary feed (0.713 ± 0.137 mg/kg dw) gosling groups (average ± standard deviation). Upon immune challenge with double-stranded RNA (dsRNA) injection, endpoints for immune responses and oxidative stress were measured after 24 h. Our results indicated that Hg exposure modulated the immune responses in Arctic barnacle goslings upon a viral-like immune challenge. Increased exposure to both environmental as well as supplemental Hg reduced the level of natural antibodies, suggesting impaired humoral immunity. Hg exposure upregulated the expression of proinflammatory genes in the spleen, including inducible nitric oxide synthase (iNOS) and interleukin 18 (IL18), suggesting Hg-induced inflammatory effects. Exposure to Hg also oxidized glutathione (GSH) to glutathione disulfide (GSSG); however, goslings were capable of maintaining the redox balance by de novo synthesis of GSH. These adverse effects on the immune responses indicated that even exposure to low, environmentally relevant levels of Hg might affect immune competence at the individual level and might even increase the susceptibility of the population to infections.

Morphological parameters of hepatocytes in the European mole (Talpa europaea) and herb field mouse (Sylvaemus uralensis) under industrial pollution: Qualitative and quantitative assessment

Morphological alterations of cells and tissues usually occur in biological organisms exposed to environmental contaminants, there by acting as a biomarker of environmental pollution, thus, making this study highly pertinent. The effect of industrial pollution on the qualitative and quantitative morphological parameters of hepatocytes (through histological analysis and cytomorphometry) was studied in two contrasting species of small mammals (Talpa europaea and Sylvaemus uralensis), taking into account the animal age (young and adult groups) and liver concentrations of heavy metals (Cu, Zn, Cd, Pb). Studies were performed in the regions exposed to emissions from two currently operating copper smelters: Middle Ural Copper Smelter (Middle Urals, T. europaea catching area) and Karabash Copper Smelter (Southern Urals, S. uralensis catching area). Seven morphometric parameters of hepatocytes were measured, of which two key parameters were selected by the method of principal components-the cell packing density and nuclear-cytoplasmic ratio (N/C). It was found that cell packing density in T. europaea from the impact zone decreased relative to the background area in young animals. At the same time, the differences in this parameter between the age groups from the background zone were leveled in the impact area of catching. The N/C ratio in T. europaea hepatocytes showed no correlation with either animal age or site of capture (background or impact area). In S. uralensis, both parameters, even taking into account the age, were found to be insensitive to indicate an effect of industrial pollution. Dystrophic changes (tested through histological analysis) in the liver tissue were revealed in all animal groups, but their frequency did not depend on any of the factors (age, zone) as well as the level of accumulation of toxic heavy metals (Cd, Pb). Morphometric parameters of hepatocytes have proved to be more reliable indicators of pollution, compared to the frequency of liver histopathology, due to lower subjectivity in their evaluation.

Investigation into clinicopathological and pathological findings, prognosis, and aetiology of lorikeet paralysis syndrome in rainbow lorikeets (Trichoglossus haematodus)

Objective

To report the temporal and spatial distribution of rainbow lorikeets presenting with lorikeet paralysis syndrome (LPS) and their clinicopathologic and pathologic findings, exposure to toxins, and response to treatment.

Methods

Records of lorikeets admitted in 2017 and 2018 to facilities in south‐east Queensland (QLD) were reviewed and LPS and non‐LPS cases were mapped and their distribution compared. Plasma biochemistries and complete blood counts were done on 20 representative lorikeets from south‐east QLD and Grafton, New South Wales (NSW). Tissues from 28 lorikeets were examined histologically. Samples were tested for pesticides (n = 19), toxic elements (n = 23), botulism (n = 15) and alcohol (n = 5).

Results

LPS occurred in warmer months. Affected lorikeets were found across south‐east QLD. Hotspots were identified in Brisbane and the Sunshine Coast. Lorikeets had a heterophilic leucocytosis, elevated muscle enzymes, uric acid and sodium and chloride. Specific lesions were not found. Exposure to cadmium was common in LPS and non‐LPS lorikeets. Treated lorikeets had a 60–93% See Table 2 depending on severity of signs.

Clinical significance

The primary differential diagnosis for lorikeets presenting with lower motor neuron signs during spring, summer and autumn in northern NSW and south‐east Queensland should be LPS. With supportive care, prognosis is fair to good.

Metalliferous Mining Pollution and Its Impact on Terrestrial and Semi-terrestrial Vertebrates: A Review

Metalliferous mining, a major source of metals and metalloids, has severe potential environmental impacts. However, the number of papers published in international peer-reviewed journals seems to be low regarding its effects in terrestrial wildlife. To the best of our knowledge, our review is the first on this topic. We used 186 studies published in scientific journals concerning metalliferous mining or mining spill pollution and their effects on terrestrial and semi-terrestrial vertebrates. We identified the working status of the mine complexes studied, the different biomarkers of exposure and effect used, and the studied taxa. Most studies (128) were developed in former mine sites and 46 in active mining areas. Additionally, although several mining accidents have occurred throughout the world, all papers about effects on terrestrial vertebrates from mining spillages were from Aznalcóllar (Spain). We also observed a lack of studies in some countries with a prominent mining industry. Despite >50% of the studies used some biomarker of effect, 42% of them only assessed exposure by measuring metal content in internal tissues or by non-invasive sampling, without considering the effect in their populations. Most studied species were birds and small mammals, with a negligible representation of reptiles and amphibians. The information gathered in this review could be helpful for future studies and protocols on the topic and it facilitates a database with valuable information on risk assessment of metalliferous mining pollution.

Feathers and hair as tools for non-destructive pollution exposure assessment in a mining site of the Iberian Pyrite Belt

Mining is responsible of releasing trace elements to the environment with potential negative effects on wildlife. Traditionally, wildlife exposure assessment has been developed by analyzing mainly environmental compartments or internal tissues. Nowadays, the use of non-destructive matrices such as hair or feathers has increased. Nevertheless, its use in free-living terrestrial mammals or in birds other than raptors or passerines is less frequent. The main objective of our study was to determine the potential for hair and feathers in a rabbit and bird species to be used as non-invasive proxy tissues for assessing internal metal concentrations at polluted sites from mining. We tested whether hair of European rabbit (Oryctolagus cuniculus) and feathers of red-legged partridge (Alectoris rufa) can be used as non-destructive biological monitoring tools of both essential (Cu, Zn) and non-essential (Pb, Cd, As) trace elements in a currently active copper mining site. We found significant different concentrations, particularly in non-essential elements, between reference area and mining site. Non-essential elements Pb and Cd showed higher correlations between tissues and hair/feathers, while few significant patterns were observed for essential elements such as Cu and Zn. Although feathers showed lower levels of correlation with internal tissues than hair, both could be useful as non-destructive biological monitoring tools. Further tissues, and more importantly, hair and feathers allowed discrimination between polluted and reference sites to indicate bioavailability and pollution status. In addition, hair and feathers can be used in monitoring pollution of an active mining site, being specially interesting for biomonitoring a certain period of time in the event of a particular episode of pollution, in addition to the chronic exposure. As occurred with hair in rabbits, feathers seem to be a good compartment to detect differences between a potential polluted area, such the surrounding of an active mine site, and a non-polluted area.

Cyto/genotoxicological evaluation of hot spots of soil pollution using Allium bioassays in relation to geochemistry

Soil from industrial and landfill sites affected by anthropogenic activity was screened for implicit negative effects in an Allium test-system in relation to geochemistry. The concentrations of 15 elements were compared to the ecotoxicologically-based soil guideline values. Admitted geoindices were used to classify test-soils according to risk/hazard categories. Test-soils were screened for the possible deleterious effects in common onion (Allium cepa L.) by employing a test battery of cytogenetic bioassays (root growth inhibition, mitotic activity, frequency of chromosome aberrations and micronuclei, and cell death rate) complemented with two assays of molecular DNA markers, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR). Soil from industrial sites was more severely polluted and more cytotoxic for onions compared to soil from landfill sites. However, the cyto/genotoxic outcome of soil exposure in A. cepa was the same for all test-soils; the detrimental effects were observed in onions treated with every test-soil. Thus, test-soils could not be classified as non- and genotoxic, although certain of them had permissible contamination levels. The chromosome aberration frequency and cell death rates were consistent with the intensity of soil contamination, contrary to the micronuclei rate, which was independent of the soil risk/hazard level. Despite a relationship between risk (RI) and total soil contamination (Z) geoindices, both indices correlated with a different Allium cyto/genotoxicity endpoint, although the Z index was preferred over the RI index as being more informative in correlation analysis. Allium bioassays complemented each other by depicting different aspects of exposure to toxic substances, and determination of cyto/genotoxicity in a battery of different bioassays is important in the risk assessment of ecologically dangerous soils, and an application of a test battery is strongly advised.

Mining in the Arctic environment - A review from ecological, socioeconomic and legal perspectives

The development of mining and other resource-based industries are among key drivers of economic development in the Arctic. The fragile environment and the presence of nature-based livelihoods and indigenous communities pose challenges for mining development. Mining operations should be optimized so that the profitability is maintained in changing market conditions and to meet increasing societal and environmental demands. In this study we present the current understanding on the interplay between mining and the surrounding socio-ecological systems in the Arctic region. The existing academic literature on the Arctic region was reviewed, covering 127 peer-reviewed publications since 2000. We investigated the mining activities from four perspectives examining: 1) environmental, 2) economic, 3) social and 4) legal dimensions, covering three life-cycle stages: 1) pre-mining, 2) mining, and 3) post-mining. The publications on the environmental and economic aspects focused principally on the impacts of mining, whereas social and legal publications discussed the interaction between people and their rights and ways of controlling their environment. Besides the need for more balanced research between different life-cycle stages we uncovered five research gaps concerning the knowledge base needed to increase the sustainability of Arctic mining: 1) impacts and adaptation to climate change, 2) monitoring the sustainability of mining using standardized indicators, 3) holistic economic assessment of mining, 4) social sustainability and conflict management, and 5) mechanisms that mitigate or compensate for the adverse effects of mining on biodiversity.

Trends in spatial patterns of heavy metal deposition on national park service lands along the Red Dog Mine haul road, Alaska, 2001-2006

Spatial patterns of Zn, Pb and Cd deposition in Cape Krusenstern National Monument (CAKR), Alaska, adjacent to the Red Dog Mine haul road, were characterized in 2001 and 2006 using Hylocomium moss tissue as a biomonitor. Elevated concentrations of Cd, Pb, and Zn in moss tissue decreased logarithmically away from the haul road and the marine port. The metals concentrations in the two years were compared using Bayesian posterior predictions on a new sampling grid to which both data sets were fit. Posterior predictions were simulated 200 times both on a coarse grid of 2,357 points and by distance-based strata including subsets of these points. Compared to 2001, Zn and Pb concentrations in 2006 were 31 to 54% lower in the 3 sampling strata closest to the haul road (0–100, 100–2000 and 2000–4000 m). Pb decreased by 40% in the stratum 4,000–5,000 m from the haul road. Cd decreased significantly by 38% immediately adjacent to the road (0–100m), had an 89% probability of a small decrease 100–2000 m from the road, and showed moderate probabilities (56–71%) for increase at greater distances. There was no significant change over time (with probabilities all ≤ 85%) for any of the 3 elements in more distant reference areas (40–60 km). As in 2001, elemental concentrations in 2006 were higher on the north side of the road. Reductions in deposition have followed a large investment in infrastructure to control fugitive dust escapement at the mine and port sites, operational controls, and road dust mitigation. Fugitive dust escapement, while much reduced, is still resulting in elevated concentrations of Zn, Pb and Cd out to 5,000 m from the haul road. Zn and Pb levels were slightly above arctic baseline values in southern CAKR reference areas.

Decreased metal accumulation in passerines as a result of reduced emissions

Technological advances in industrial processes have resulted in reduced atmospheric emissions from metal industries all over the globe, but the response of the environment is not well known. The authors studied metal (As, Cd, Cu, Ni, Pb, and Se) accumulation in passerine birds (pied flycatcher, Ficedula hypoleuca, and great tit, Parus major) following almost 20 years of reduced metal emissions from the largest nonferrous smelter in Finland. Close to the industry, emission reductions resulted in reduced exposure to several of the elements and, more importantly, reduced accumulation by 58 to 95% in liver tissue. Albeit showing significant tissue reductions, nestlings had elevated concentrations of arsenic, cadmium, lead, and selenium close to the industry. Single-element concentrations were below critical levels associated with subclinical effects, but the mixture of toxic elements indirectly affected health and reproduction. Our study indicates that in environments with moderate duration of industrial activity, impact, and soil pollution, metal accumulation in organisms can decrease relatively rapidly when atmospheric emissions are reduced.

Concentrations and bioaccessibility of metals in vegetation and dust near a mining haul road, Cape Krusenstern National Monument, Alaska

Vegetation, sub-surface peat, and road dust were sampled near the Delong Mountain Transportation System (DMTS) haul road in northwest Alaska in 2005-2006 to document aluminum, barium, cadmium, lead, and zinc concentrations, and to evaluate bioaccessibility of these metals. The DMTS haul road is the transport corridor between Red Dog Mine (a large-scale, lead-zinc mine and mill) and the coastal shipping port, and it traverses National Park Service lands. Compared to reference locations, total metal concentrations in four types of vegetation (birch, cranberry, and willow leaves, and cotton grass blades/stalks) collected 25 m from the haul road were enriched on average by factors of 3.5 for zinc, 8.0 for barium, 20 for cadmium, and 150 for lead. Triple rinsing of vegetation with a water/methanol mixture reduced metals concentrations by at most 50%, and cadmium and zinc concentrations were least affected by rinsing. Cadmium and zinc bioaccessibility was greater in vegetation (50% to 100%) than in dust (15% to 20%); whereas the opposite pattern was observed for lead bioaccessibility (<30% in vegetation; 50% in dust). Barium exhibited low-to-intermediate bioaccessibility in dust and vegetation (20% to 40%), whereas aluminum bioaccessibility was relatively low (<6%) in all sample types. Our reconnaissance-level study indicates that clean-up and improvements in lead/zinc concentrate transfer activities have been effective; however, as of 2006, metal dispersion from past and/or present releases of fugitive dusts along the DMTS road still may have been contributing to elevated metals in surface vegetation. Vegetation was most enriched in lead, but because bioaccessibility of cadmium was greater, any potential risks to animals that forage near the haul road might be equally important for both of these metals.