Tissues and hair residues and histopathology in wild rats (Rattus rattus L.) and Algerian mice (Mus spretus Lataste) from an abandoned mine area (Southeast Portugal)

Evaluating washing techniques to eliminate external contamination of trace elements in bat fur and bird feathers

Non-invasive proxies, such as fur and feathers, are likely to be increasingly used to assess the potential exposure of chemicals, including trace metals and metalloids. However, the amount of external contamination is usually unknown, and there is no standard method for removing external contamination of trace metals in fur or feathers. To date, 40 % of studies published related to the measurement of trace metal levels in fur or the hair of non-human mammals and 24 % of studies in feathers do not state any washing methods or did not wash the samples before analysis. We assessed three washing techniques to remove external contamination of arsenic (As), lead (Pb), and zinc (Zn) from bat fur. We selected the three most frequently used fur washing methods from literature. To test these methods, fur samples from great flying foxes (Pteropus neohibernicus neohibernicus, n=15 individuals) from Papua New Guinea preserved over eight decades (AMNH, USA) were used. Percentages of trace metal removed are 87.19 % (SD= 12.28), 92.99 % (SD= 5.5) and 88.57 % (SD= 9.33) for As, 54.72 % (SD= 31.64), 55.89 % (SD= 37.87), and 53.93 % (SD= 41.28) for Pb, and 74.03 % (SD= 22.96), 22.93 % (SD= 73), and 24.95 % (SD= 49.5) for Zn using M2, M3, and M4, respectively. We also assessed four washing techniques to remove external contamination of arsenic (As), mercury (Hg), and zinc (Zn) from bird feathers. We identified the four most prevalent washing techniques in the literature used for feathers. We used feathers from the great horned owl (Bubo virginianus) and the great blue heron (Ardea herodias) to test these methods. Percentages of trace metal removed are 34.35 % (SD= 44.22), 69.22 % (SD= 36.5), 62.59 % (SD= 48.37), and 80.89 % (SD= 14.54) for As, 66.97 % (SD= 13.26), 29.4 % (SD= 67.06), 49.68 % (SD= 42.33), and 28.88 % (SD= 69) for Hg, and <0 % (SD= 80.1), 0 % (SD= 29.55), 11.23 % (SD= 47.73), and 57.09 % (SD= 21.2) for Zn using M2, M3, M4, and M5, respectively. This study shows the importance of washing fur and feather samples prior to trace metals analyses in ecotoxicology and biomonitoring studies.

Physiological strategies in wild rodents: immune defenses of commensal rats

The importance of issues associated with urban/commensal rats and mice (property damage, management costs, and health risks) press upon research on these animals. While the demography of commensal rodents is mostly studied, the need for understanding factors influencing their natural morbidity/mortality is also stressed. In this respect, more attention is expected to be paid to immunity, the physiological mechanism of defense against host survival threats (pathogens, parasites, diseases). Commensal rats and mice carry numerous pathogens that evoke diverse immune responses. The state of immunity in commensal house mice is studied in great detail, owing to the use of laboratory strains in biomedical research. Because commensal rats are, compared to mice, carriers of more zoonotic agents, rats' immunity is studied mainly in that context. Some of these zoonotic agents cause chronic, asymptomatic infections, which justified studies of immunological mechanisms of pathogen tolerance versus clearance regulation in rats. Occurrence of some infections in specific tissues/organs pressed upon analysis of local/regional immune responses and/or immunopathology. A survey of immunological activity/responses in commensal rats is given in this review, with mention of existing data in commensal mice. It should throw some light on the factors relevant to their morbidity and lifespan, supplementing the knowledge of commensal rodent ecology.

Review: Abandoned mines as a resource or liability for wildlife

Abandoned Mine Lands (AMLs) are areas where previous mineral extraction or processing has occurred. Hundreds of thousands of AMLs exist within the United States. Contaminated runoff from AMLs can negatively affect the physiology and ecology of surrounding terrestrial and aquatic habitats and species and can be detrimental to human health. As a response, several U.S. federal and state agencies have launched programs to assess health risks associated with AMLs. In some cases, however, AMLs may be beneficial to specific wildlife taxa. There is a relative paucity of studies investigating the physiological and ecological impacts of AMLs on wildlife. We conducted a systematic review examining published scientific articles that assessed the negative and positive impacts of AMLs across invertebrate and vertebrate taxa. We also offer suggestions on evaluating AMLs to develop effective mitigation strategies that reduce their negative tole on human and wildlife communities. Peer-reviewed publications were screened across WebofScience, PubMed and Google Scholar databases. Abandoned mine lands were generally detrimental to wildlife, with adverse effects ranging from bioaccumulation of heavy metals to decreased ecological fitness. Conversely, AMLs were an overall benefit to imperiled bat populations and could serve as tools for conservation. Studies were unevenly distributed across different wildlife taxa groups, echoing the necessity for additional taxonomically diverse research. We suggest that standardized wildlife survey methods be used to assess how different species utilize AMLs. Federal and state agencies can use these surveys to establish effective remediation plans for individual AML sites and minimize the risks to both wildlife and humans.

Effect of urbanization on the trace element concentrations in the kidney, liver and spines of the European hedgehog (Erinaceus europaeus)

Urbanized environments may be suitable for some wild species, like the European hedgehog (Erinaceus europaeus). However, the (sub)urban areas are source of several pollutants, such as trace elements (TEs). The main objective of our study is to investigate the role of the European hedgehog as a potential bioindicator species for seven TEs (As, Cd, Cr, Cu, Ni, Pb, Zn) in a big urban agglomeration. We analyzed the kidney, liver and spines of 50 European hedgehogs. Moreover, we carried out geographic information system (GIS) with 31 individuals to examine the effects of human pressure (human density and urbanization) on TE concentrations in tissues. We detected the 7 TEs in all tissues. Trace elements, especially Pb and Zn, in the liver, kidney and spines seem to be influenced by human density and urbanization.

The first full study of heavy metal(loid)s in western-European hedgehogs (Erinaceus europaeus) from Portugal

The western-European hedgehog (Erinaceus europaeus) is an insectivore with a wide distribution in Portugal and a potential tool for biomonitoring relevant One Health hazards, including heavy metal(loid)s' pollution. The aim of this study was to positively contribute to the current knowledge about the metal(loid) pollution in Portugal. Forty-six hedgehogs (from rescue centres; with known provenance) were necropsied. Sex, age category and weight were determined. Spines, liver and kidney were collected, and metalloid concentrations were determined by inductively coupled plasma mass spectrophotometry (ICP-MS). In general, results did not present alarming metal(loid) concentrations, with the exception of cadmium (Cd) (in the kidneys) and copper (Cu). Hedgehogs from Viana do Castelo and Viseu showed elevated concentrations of arsenic (As) and Castelo Branco presented concerning values of cadmium (Cd). Adult and heavier hedgehogs tended to present higher levels of metal(loid)s. Sex does not seem to significantly affect the metal(loid)s' concentrations. Further analysis would be needed to prioritize areas with detail and allow the application of the necessary mitigation strategies.

Metal and metalloid concentrations in wild mammals from SW Europe: European hedgehog (Erinaceus europaeus) and badger (Meles meles)

In recent years, there have been increasing ecological and global concerns associated to Potentially Toxic Elements (PTEs). Thus, the relevance of wild mammals as biomonitors has been globally recognised. In the present study, Cd, Pb, Hg, Zn and As concentrations were quantified in European hedgehog and badger inhabiting SW Europe, and cumulative trends in relation to age and sex were evaluated. Liver and kidney samples were collected, mineralised and PTE content was determined by ICP-MS. Zn was the most abundant element quantified in both organs (239 and 89.8 mg kg-1 for hedgehogs and 179 and 164 mg kg-1 dw for badgers). In hedgehogs, very high Hg concentration were quantified (4.35 and 15.5 mg kg-1 dw in liver and kidney), and Cd was the most abundant for badgers (4.70 and 7.61 mg kg-1 dw in liver and kidney). Positive correlations were observed for the concentrations of PTE in the organs of both species. Age-dependence increased only Cd concentration, with levels in adult kidneys being significantly higher. In this study, European hedgehog and badger were used as biomonitors for the determination of PTEs to provide current reference values in relatively non-polluted areas of SW Europe, and to enhance the use of these species for future ecotoxicological studies.

Concentrations of iron and chromium in free-ranging common marmosets (Callithrix jacchus) from Pernambuco, Brazil

Common marmosets (Callithrix jacchus) are widely distributed in Northeast Brazil and often inhabit urban and peri-urban forest areas close to human settlements. Given its wide territorial distribution, its proximity to human populations, and its exposure to environmental degradations originating from urbanization, common marmosets have a high potential for environmental biomonitoring. The concentrations of iron (Fe) and chromium (Cr) were quantified in the liver, hair, and bone of 22 free-ranging common marmosets' bodies from nine cities from Pernambuco State, Brazil, using inductively coupled plasma optical emission spectrometry (ICP OES). The liver showed the highest concentrations of Fe and Cr (3773.2 ± 3715.8 mg/kg and 19.4 ± 41.6 mg/kg, respectively); the lowest concentration of Fe was detected in the bone (111.6 ± 97.6 mg/kg) and of Cr in the hair (3.3 ± 1.5 mg/kg). There was a moderate positive correlation between Fe and Cr in the liver (r = 0.64) and a high negative correlation for Cr between bone and hair (r = -0.65). This study demonstrated the bioaccumulation of Fe and Cr in hair, liver, and bone in common marmosets. The highest average concentration of Fe and Cr occurred in animals from Recife, Jaboatão dos Guararapes, and Paulista, respectively, the 1^st, the 2^nd, and the 5^th most populated cities in the state of Pernambuco. The presence of high concentrations of metals in animals from Recife and nearby cities can indicate alarming levels of environmental pollution in these locations.

Deposition of heavy metals in biological tissues of workers in metal workshops

Welding and cutting of metals produce large amounts of particulate matter (PM), which poses a significant health risk to exposed workers. Appropriate biological markers to estimate exposure are of great interest for occupational health and safety. Here, hair and nail samples from metal workers were analyzed, which appear to be more suitable than blood or urine samples for assessing long-term exposure. Four workshops working with steel components were included in the study. The hair and nail samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentrations of 12 elements. At the workplaces, the concentrations of 15 elements in particulate matter were determined using X-ray fluorescence (XRF) and particle-induced X-ray emission (PIXE) techniques. The hair and nail samples of the workers contained significantly higher metal concentrations than the analytical results of a nonexposed control group. The most significant difference between the groups was found for Ti, Mn, Fe, and Co.

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.

Multiple trace elements exposure of Grey-cheeked Fulvettas Alcippe morrisonia, a nuclear member in bird mixed-species flocks, and implications for bioindicator

Birds are vulnerable to metal pollution, which can serve as indicators of environmental safety monitoring. In this study, we evaluated three non-essential (Pb, Cd, and As) and two essential (Cu and Zn) trace elements of living (only feathers) and deceased (feathers and tissues) Grey-cheeked Fulvetta (Alcippe morrisonia) at a highly polluted mine tailings and a reference site. Five metal concentrations in the feathers of living Grey-cheeked Fulvettas were higher at the mine site. Among these, the levels of Cd and Pb in most feathers exceeded the threshold, resulting in an ecotoxicological concern. The correlation analysis suggested that feathers from Grey-cheeked Fulvettas might be useful bioindicators for local metal contamination assessment. The toxicological effects of trace metals on Grey-cheeked Fulvetta might affect its leadership ability. Therefore, understanding the effects of metal pollution on Grey-cheeked Fulvetta would show important practical implications for the conservation of bird communities.

The elemental composition of small mammals in a commercial orchard-meadow system

We analyze concentrations of various elements in small mammals from commercial orchards and berry plantations and test differences between them depending on species, individual body mass, age, gender, type and age of crop and intensity of applied agricultural measures. Skinned front legs (muscle and bones) were used to register the presence and concentration of Ca, Cd, Mo, Ni, Se, Ag, As, Be, Bi, Co, Cr, Cu, Fe, Ga, Mg, Mn, Pb, Sr, U, V and Zn. The most abundant species were common vole (Microtus arvalis), yellow-necked (Apodemus flavicollis) and striped field (A. agrarius) mice. The maximum recorded concentrations exceeded the minimums by 1.7-7.7 times in Mg, Zn, Cu, Ga, Ni and Ca, and 11.0-23.2 times in Mn, Be, Mo, Co, Sr, V, Pb and As. The hypothesis that the use of fertilization and pesticides in commercial orchards should induce differences in the elemental concentrations between crop areas and control habitats was confirmed by the higher concentrations of Cu, Mn, Bi, Co, Cr, Fe, Ni, Sr and Pb in rodents from the crop areas. Spatially controlled generalized linear mixed model confirmed the cumulative influence of species and crop, explaining 30-80% of the distribution of Ca, Ni, Co, Cu, Ga, Mn, Pb and U. The effect of species and the age of the individual was significant for Ni, Co, Cu, Fe, Ga, Mn and Pb, while effect of gender was not expressed. Depletion of Cu in older individuals was found in all three species. With species as a grouping factor, the effect of crop type and the intensity of agricultural practices were significant factors in the accumulation of Ca, Ni, Co, Cu, Ga, Mn and Pb, while effect of crop age was not expressed. The obtained elemental concentrations in rodents indicated orchards to be cleaner than heavy polluted areas.

The price of persistence: Assessing the drivers and health implications of metal levels in indicator carnivores inhabiting an agriculturally fragmented landscape

Patterns and practices of agricultural expansion threaten the persistence of global biodiversity. Wildlife species surviving large-scale land use changes can be exposed to a suite of contaminants that may deleteriously impact their health. There is a paucity of data concerning the ecotoxicological impacts associated with the global palm oil (Elaeis guineensis) industry. We sampled wild Malay civets (Viverra tangalunga) across a patchwork landscape degraded by oil palm agriculture in Sabah, Malaysian Borneo. Using a non-lethal methodology, we quantified the levels of 13 essential and non-essential metals within the hair of this adaptable small carnivore. We robustly assessed the biological and environmental drivers of intrapopulation variation in measured levels. Metal concentrations were associated with civet age, weight, proximity to a tributary, and access to oxbow lakes. In a targeted case study, the hair metal profiles of 16 GPS-collared male civets with differing space use patterns were contrasted. Civets that entered oil palm plantations expressed elevated aluminium, cadmium, and lead, and lower mercury hair concentrations compared to civets that remained exclusively within the forest. Finally, we paired hair metal concentrations with 34 blood-based health markers to evaluate the possible sub-lethal physiological effects associated with varied hair metal levels. Our multi-facetted approach establishes these adaptable carnivores as indicator species within an extensively altered ecosystem, and provides critical and timely evidence for future studies.

Metal Bioaccumulation, Cytogenetic and Clinico-Biochemical Alterations in Rattus norvegicus Exposed In Situ to a Municipal Solid Waste Landfill in Lagos, Nigeria

This study aimed at determining in animal model the health effects of in situ exposure to landfill chemicals. We evaluated metal concentrations in tissues and cytogenetic and clinico-biochemical effects in Wistar rats (Rattus norvegicus) exposed in situ at Olusosun landfill in Lagos, Nigeria. Male rats (n = 30/point) were exposed at three different points to ambient air and underground water (via drinking) at the landfill for 4-, 8-, 12-, 16-, 20- and 24-week periods. Rats concurrently sited at a residential area, 17.3 km from the landfill site served as control. There was significantly (p < 0.05) time-dependent: accumulation of lead, cadmium, chromium, copper and zinc in the liver and kidney and increase in body weight gain, in exposed rats compared to control. There was significant induction of micronuclei and cytotoxicity (reduced PCE/NCE ratios) in exposed rats. Haematological parameters (RBC, PCV, Hb and WBC) and serum biomarkers of hepato-renal damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) activities; creatinine and urea levels] revealed significant increases. There was significant increase in hepatic levels of reduced glutathione, malondialdehyde, catalase activities, and decrease in superoxide dismutase, at all periods. Chromium and copper concentrations in the liver and kidney revealed significant positive correlations with either one or more of AST, ALT, LDH and urea. Significant metal concentrations in the underground water and tissues suggest that heavy metals are responsible for the observed alterations, and this may have been via oxidative stress. These findings suggest potential health risk due to occupational and residential exposure to landfill pollutants.

Evidence of micro-evolution in Crocidura russula from two abandoned heavy metal mines: potential use of Cytb, CYP1A1, and p53 as gene biomarkers

Heavy metals accumulated in the environment due to the mining industry may impact on the health of exposed wild animals with consequences at the population level via survival and selection of the most resistant individuals. The detection and quantification of shifts in gene frequencies or in the genetic structure in populations inhabiting polluted sites may be used as early indicators of environmental stress and reveal potential 'candidate gene biomarkers' for environmental health assessment. We had previously observed that specimens of the Greater white-toothed shrew (Crocidura russula) from two heavy metal mines in Southern Portugal (the Aljustrel and the Preguiça mines) carried physiological alterations compared to shrews from an unpolluted site. Here, we further investigated whether these populations showed genetic differences in genes relevant for physiological homeostasis and/or that are associated with pathways altered in animals living under chronic exposure to pollution, and which could be used as biomarkers. We analysed the mitochondrial cytochrome b (Cytb) gene and intronic and/or exonic regions of four nuclear genes: CYP1A1, LCAT, PRPF31, and p53. We observed (1) population differences in allele frequencies, types of variation, and diversity parameters in the Cytb, CYP1A1, and p53 genes; (2) purifying selection of Cytb in the mine populations; (3) genetic differentiation of the two mine populations from the reference by the p53 gene. Adding to our previous observations with Mus spretus, we provide unequivocal evidence of a population effect exerted by the contaminated environment of the mines on the local species of small mammals.

Domestic cats as environmental lead sentinels in low-income populations: a One Health pilot study sampling the fur of animals presented to a high-volume spay/neuter clinic

Non-human animals serve as sentinels for numerous issues affecting humans, including exposure to toxic heavy metals like lead. Lead plays a role in perpetuating cycles of poverty in low-income communities due to the inequitable distributions of indoor health risks from lower-quality housing and outdoor health risks from industry and polluters, compounded by inequitable distributions of heath care and education. In this pilot study, we explore the potential for studying lead in low-income populations by partnering with nonprofit veterinary outreach programs. We investigate the lead concentration in fur samples of 85 domestic cats (Felis catus) presented to a high-volume spay/neuter clinic and report a mean of 0.723 μg of lead per gram of fur. This study reveals new information about lead exposure in cats in the USA, including that females had greater lead exposure than males, lead exposure increased with increasing amount of access to the outdoors, and lead exposure increased in cats with decreased body condition. We propose that pet, feral, and free-roaming cats presented to high-volume spay/neuter clinics could serve as a source of data about lead exposure in disadvantaged communities where these clinics already operate. Such a non-invasive surveillance system using inert, unobtrusively obtained samples could be deployed to detect highly exposed cats, prompting to follow up contact to a cat's caretakers to recommend seeking lead testing for themselves, their families, and their neighbors.

Lead exposure in dogs fed game meat and offal from culled invasive species in El Palmar National Park, Argentina

This is the first field study to evaluate lead exposure in dogs fed game meat and offal and, to our knowledge, the first study exploring associations between game consumption and dog health status. We quantified lead concentrations in blood and hair and haematological parameters of 31 dogs fed game meat and offal from wild boar (Sus scrofa) and axis deer (Axis axis) culled with lead ammunition in El Palmar National Park, Argentina. Despite variable weekly frequency in game consumption, dogs had detectable blood and hair lead levels, demonstrating recent and chronic exposure. Lead geometric mean and SD were 18.91 ± 346.85 μg/dL w.w. in blood (range = 0.53-216.58), and 0.721 ± 6.444 μg/gr d.w. in hair (range = 0.007-34.800). Hair lead levels were relatively low in most samples, except for the oldest dog which had an atypically high value concurrent with anaemia, a common outcome of chronic lead exposure. Dog's owner was significantly predictive of both blood and hair lead levels, which reflects the same feeding patterns for all dogs owned by the same person. Body condition was associated with hair lead, with dogs in good condition presenting higher lead levels. This could be related to greater game consumption by those dogs, resulting in higher lead ingestion. Dogs fed game meat and offal at very low or low frequency (≤4 times per week) showed higher blood lead levels, suggesting there might not be a risk-free frequency for game provision to dogs. Considering the risks of dietary lead exposure, avoiding feeding dogs lead-killed game and replacing lead ammunition with non-toxic alternatives are recommended. This would allow using hunted game as a valuable food resource without unnecessary risk for the health of consumers and the environment.

Elemental and radionuclide exposures and uptakes by small rodents, invertebrates, and vegetation at active and post-production uranium mines in the Grand Canyon watershed

The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized the exposure of biota to uranium and co-occurring ore body elements during active ore production and at a site where ore production had recently concluded. Our results indicate that biota have taken up uranium and other elements (e.g., arsenic, cadmium, copper, molybdenum, uranium) from exposure to ore and surficial contamination, like blowing dust. Results indicate the potential for prolonged exposure to elements and radionuclides upon conclusion of active ore production. Mean radium-226 in deer mice was up to 4 times greater than uranium-234 and uranium-238 in those same samples; this may indicate a potential for, but does not necessarily imply, radium-226 toxicity. Soil screening benchmarks for uranium and molybdenum and other toxicity thresholds for arsenic, copper, selenium, uranium (e.g., growth effects) were exceeded in vegetation, invertebrates, and rodents (Peromyscus spp., Thomomys bottae, Tamias dorsalis, Dipodomys deserti). However, the prevalence and severity of microscopic lesions in rodent tissues (as direct evidence of biological effects of uptake and exposure) could not be definitively linked to mining. Our data indicate that land managers might consider factors like species, seasonal changes in environmental concentrations, and bioavailability, when determining mine permitting and remediation in the Grand Canyon watershed. Ultimately, our results will be useful for site-specific ecological risk analysis and can support future decisions regarding the mineral extraction withdrawal in the Grand Canyon watershed and elsewhere.

Multimarker approach to assess the exposure of the wild rodent Calomys laucha to a simulated crude oil spill

A mysterious oil spill occurred in the ocean near Brazil in 2019, which affected coastal areas in northeastern Brazil. When oil pollution occurs in coastal zones, organisms such as small mammals can suffer deleterious effects to their health. This study aimed to evaluate the effects of exposure to contaminated sandy soil with different crude oil concentrations in males of the species Calomys laucha. The exposure to crude oil resulted in multiple health issues for the subjects in the very first days of exposure. Furthermore, the exposure resulted in mutagenic damage to bone marrow blood cells and behavioral and morphological alterations, which were almost always in a dose-dependent form. The present study demonstrates the sensibility of the biomarkers used and highlights that small wild mammals such as C. laucha are useful for predicting environmental damage caused by the exposure to crude oil.

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.

Nilonema gymnarchi (Nematoda: Philometridae) and trace metals in Gymnarchus niloticus of Epe lagoon in Lagos State, Nigeria

The presence of trace metals in the sediment, water, and biota of the Epe lagoon has been recently linked to oil exploration and municipal perturbations around the lagoon. The study was aimed at assessing the concentrations and associated health risks of Fe, Zn, Cu, Ni, Pb, Cd, Cr, Mn, Co and V in the water, sediment, and Gymnarchus niloticus of Epe lagoon and to evaluate the role of the enteric parasite Nilonema gymnarchi in bioaccumulation of the metals in the fish. The temperature, pH, redox potential, conductivity, turbidity, dissolved oxygen (DO), total dissolved solids (TDS), and salinity were determined in-situ using a handheld multi-parameter probe (Horiba Water Checker Model U-10). The concentrations of Fe, Zn, Cu, Ni, Pb, Cd, Cr, Mn, Co, and V were determined in the surface water, bottom sediment, Gymnarchus niloticus, and its enteric parasites, Nilonema gymnarchi in Epe lagoon using the Flame Atomic Absorption Spectrometer (Philips model PU 9100). The bioaccumulation factors and target hazard quotients of the trace metals in the infected and uninfected fish were estimated and compared. The intestinal tissue sections of the infected and uninfected fish were examined using a binocular dissecting microscope (American Optical Corporation, Model 570) using hematoxylin and eosin (H&E) stain. Biochemical markers such as reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (MDA) were determined in the liver of the infected and uninfected fish. The SOD level was higher in the uninfected fish than the infected ones supports the indications deduced from the bioaccumulation analysis. Strong positive correlations between SOD and most of the metals- Fe (0.916), Zn (0.919), Cu (0.896), and Ni (0.917) suggests that the metals may have inflicted more toxicity in the uninfected. The histopathological comparisons made between the uninfected and infected fish showed consistency with the outcomes of other comparisons made in this study. These evidence were marked by tissue alterations in the infected fish ranging from no observed changes to mild alterations, while the uninfected exhibited more severe tissue injuries such as hemorrhagic lesions, severe vascular congestion, edema, the increased connective tissue of the submucosa, and vascular congestion. The condition factors of the infected (0.252) and uninfected (0.268) fish indicated slenderness and unfitness possibly due to environmental stressors such as trace metals. The parasitized fish showing better-coping potentials than the uninfected, coupled with the significant bioaccumulation interferences exhibited by the parasite Nilonema gymnarchi is an indication that the parasites may be a good metal sequestration agent for the fish and can be used to forestall the significant health hazard quotient posed by the current level of iron and the synergy of all metals analyzed in the lagoon.

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.

Are soft tissues of urban rats good indicators of exposure to heavy metal pollution? A study conducted in one of the most polluted basins of Buenos Aires, Argentina

The overall goal of this work was to analyze the relationship between the concentration of lead in the kidney, liver, and stomach contents of rats captured in a polluted urban basin and the concentration of this metal in the environment, meteorological factors, and different intrinsic characteristics of the individuals. To this end, we determined the concentration of lead in the kidney, liver, and stomach contents of 133 Norway rats (Rattus norvegicus) captured in the Matanza-Riachuelo River Basin (Buenos Aires, Argentina). This basin is one of the most severe cases of water pollution in Latin America and metals like lead represent the most common chemical pollutants. Rats were trapped in nine sites with different soil and water lead concentrations, between 2014 and 2015. A positive relationship was found between lead concentration in the liver and kidney of R. norvegicus and the environmental concentration of this metal in water and soil. Although the remaining variables analyzed were also related to the lead concentration in soft tissues, they did not affect the association between the lead concentration in soft tissues and that in the environment. The lead concentration in the stomach contents was not related to any of the variables analyzed. Our results constitute the first study in an urban basin with a gradient of environmental lead concentration and suggest that the quantification of lead in the kidney and liver of rats can be used as an indicator of exposure to this metal within a large city.

Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.

Heavy metal accumulation and genotoxic effects in levant vole (Microtus guentheri) collected from contaminated areas due to mining activities

Heavy metal contamination is a serious environmental problem commonly monitored in various organisms. Small wild rodents are ideal biological monitors to show the extent of environmental pollution. The aim of this study was to evaluate the adverse effects of marble and stone quarries on the Levant vole, Microtus guentheri, inhabiting some polluted sites. In this context, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to analyze distribution of thirteen heavy metals (Fe, Al, Zn, Cu, Cr, Mn, Ni, B, Pb, As, Co, Cd, and Hg) in the organs (skins, bones, muscles, livers and kidneys) of the biological specimens, and the comet assay revealed DNA damage in blood lymphocytes for the first time. This study was conducted at close to the marble and stone quarries at Korkuteli, Antalya-Turkey during spring, summer, autumn (2017) and winter (2018) seasons. In spring and summer, genetic damage in blood lymphocytes from all polluted sites (sites 1-5) was significantly higher than that of controls, while in autumn it was higher in samples from three sites (sites 3-5). In terms of heavy metal distribution in organs, we found depositions of Fe, Al, Zn, Ni, Mn, Cr, Co, As and Pb primarily in the skin with its derivatives, Cu and Cd deposits in the kidney, Cu, Cd and B deposits in the liver, and As and Pb depositions in the bones. The study shows that certain organs (especially skin with its derivatives) and blood lymphocytes of Levant vole can be used as ideal indicators of heavy metal pollution. Our results suggest that the Korkuteli area could already be under the threat of heavy metal pollution.

Wing membrane and fur samples as reliable biological matrices to measure bioaccumulation of metals and metalloids in bats

There is a growing conservation concern about the possible consequences of environmental contamination in the health of bat communities. Most studies on the effects of contaminants in bats have been focused on organic contaminants, and the consequences of bat exposure to metals and metalloids remain largely unknown. The aim of this study was to evaluate the suitability of external biological matrices (fur and wing membrane) for the assessment of exposure and bioaccumulation of metals in bats. The concentration of arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, selenium and zinc was measured in internal organs (liver, heart, brain), internal (bone) and external tissues (wing membrane, fur) collected from bat carcasses of four species (Hypsugo savii, Nyctalus leisleri, Pipistrellus pipistrellus, Pipistrellus pygmaeus) obtained in windfarm mortality searches. With the exception of zinc (P = 0.223), the results showed significant differences between the concentrations of metals in the analyzed tissues for all metals (P < 0.05). Significant differences were also found between organs/tissues (P < 0.001), metals (P < 0.001) and a significant interaction between organs/tissues and metals was found (P < 0.001). Despite these results, the patterns in terms of metal accumulation were similar for all samples. Depending on the metal, the organ/tissue that showed the highest concentrations varied, but fur and wing had the highest concentrations for most metals. The variability obtained in terms of metal concentrations in different tissues highlights the need to define standardized methods capable of being applied in monitoring bat populations worldwide. The results indicate that wing membrane and fur, biological matrices that may be collected from living bats, yield reliable results and may be useful for studies on bats ecotoxicology, coupled to a standardized protocol for large-scale investigation of metal accumulation.

Population effects of heavy metal pollution in wild Algerian mice (Mus spretus)

Heavy metal mining is one of the largest sources of environmental pollution. The analysis of different types of biomarkers in sentinel species living in contaminated areas provides a measure of the degree of the ecological impact of pollution and is thus a valuable tool for human and environmental risk assessments. In previous studies we found that specimens from two populations of the Algerian mice (Mus spretus) living in two abandoned heavy metal mines (Aljustrel and Preguiça, Portugal) had higher body burdens of heavy metals, which led to alterations in enzymatic activities and in haematological, histological and genotoxic parameters, than mice from a nearby reference population. We have now analysed individuals from the same sites at the biometric and genetic levels to get a broader portrayal of the impact of heavy metal pollution on biodiversity, from molecules to populations. Size and shape variations of the mouse mandible were searched by implementing the geometric morphometric method. Population genetic differentiation and diversity parameters (φST estimates; nucleotide and haplotype diversities) were studied using the mitochondrial cytochrome b gene (Cytb) and the control region (CR). The morphometric analyses revealed that animals from the three sites differed significantly in the shape of the mandible, but mandibular shape varied in a more resembling way within individuals of both mine sites, which is highly suggestive for an effect of environmental quality on normal development pathways in Algerian mice. Also, antisymmetry in mandible size and shape was detected in all populations, making these traits not reliable indicators of developmental instability. Overall little genetic differentiation was found among the three populations, although pairwise φST comparisons revealed that the Aljustrel and the Preguiça populations were each differentiated from the other two populations in Cytb and in CR, respectively. Genetic diversity parameters revealed higher genetic diversity for Cytb in the population from Aljustrel, while in the population from Preguiça diversity of the two markers changed in opposite directions, higher genetic diversity in CR and lower in Cytb, compared to the reference population. Demographic changes and increased mutation rates may explain these findings. We show that developmental patterns and genetic composition of wild populations of a small mammal can be affected by chronic heavy metal exposure within a relatively short time. Anthropogenic stress may thus influence the evolutionary path of natural populations, with largely unpredictable ecological costs.

Structural-functional modifications of the liver to chronic radioactive exposure in pygmy wood mouse (Apodemus uralensis) within the East-Urals Radioactive Trace

The hepatic parameters (contents of glycogen, total lipids, nuclear and cytoplasmic proteins, DNA and RNA, fructose-6-phosphate, water, lipid peroxidation products, as well as activities of succinate dehydrogenase and glucose phosphate isomerase), radiometric data, and the relative population abundance of the pygmy wood mouse (Apodemus uralensis Pall., 1811) inhabiting natural (Middle Urals, Southern Urals, and Trans-Urals) areas and radioactivity territory (the EURT zone after of the Kyshtym accident in the South Urals in 1957) were analysed. Structural-functional modifications of the liver in A. uralensis from the EURT area are presented, taking into account irradiation power by dose-forming radionuclides (external and internal exposure to ¹³⁷Cs and ⁹⁰Sr), population size, and reproductive status (sexually immature and sexually mature yearlings, representing different ontogenetic patterns). The sexually immature mice from the EURT area can be considered to be the more sensitive (reactive) intrapopulation group to synergistic factors, such as radiation burden and population overabundance. The extent of structural-functional hepatic modification under current conditions of radionuclide exposure, in addition to the 60 year long effect of radioactive contamination in the EURT, can exceed the level of natural (geographic) variation observed in this species in the Urals region, which points to a long term evolutionary-ecological process.

A study on the concentration of heavy metals and histopathological changes in Persian jirds (Mammals; Rodentia), affected by mining activities in an iron ore mine in Iran

Mining activity constitutes a potential source of heavy metal pollution in the environment. Long-term exposure to heavy metals (e.g., cadmium) has adverse health effects. Rodents frequently serve as bioindicators to monitor the levels of heavy metals in the environment. In the present study, concentrations of 10 heavy metals (Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Sb, and Zn) in kidney, liver, and muscle tissue of the Persian jird (Meriones persicus) were evaluated. This is the first study to examine the histopathological changes in Persian jird tissues caused by the bioaccumulation heavy metals. The samples were taken at location that surrounded by Sangan Iron Ore Mine (SIOM) mining activities, in northeastern Iran. The results show that the highest concentrations for the metals were observed in kidney and liver, whereas lowest concentrations were found in muscle of Persian jirds. The concentration of Pb was below the limit of detection. Sex and age were two factors that could explain the different levels of heavy metal bioaccumulation, which affects the concentration of some metals. Adults had significantly higher Cu and Cd levels compared to juveniles. Males bioaccumulated more Zn in their kidneys than females, whereas females bioaccumulated more Fe in their livers. As expected, heavy metals affected various organs of the studied specimens. Hyperemia, hemorrhage, necrosis, and degenerative damage to the epithelial cells of the tubules, the presence of hyaline casts, and in one case, mononuclear leukocyte infiltration, were observed in samples of renal tissue. Hemorrhage and hepatocyte vacuolization were the most common histopathological changes found in samples of hepatic tissue. These effects and the concentrations of heavy metals in the studied specimens indicate the need for monitoring and frequent sampling to evaluate long-term persistent pollutants.

Characterization of leachates from waste landfill sites in a religious camp along Lagos-Ibadan expressway, Nigeria and its hepatotoxicity in rats

Landfill sites near human settlements are known to have adverse health effects. Here, we investigated the effect of different concentrations of leachates from the Redemption Camp landfill (RCLL, 10%, 30%, 50%) on the liver of adult female rats after 21 days of exposure in their drinking water. The physicochemical and metal analyses showed that biochemical oxygen and chemical oxygen demand, zinc and magnesium levels were significantly high, whereas copper level was low in RCLL when compared to water samples from residential areas close to the landfill site, and were higher than the acceptable limits (p < 0.05). The predominant bacteria isolates recovered from the leachate and drinking water samples were Escherichia coli, Salmonella spp and Shigella spp. At the end of the 21-day exposure, RCLL increased the weight of the liver. Malondialdehyde concentrations were increased and glutathione levels were decreased significantly in the liver of treated animals at all concentrations of leachates tested. Furthermore, the activities of serum alanine amino transferase, aspartate amino transferase, gamma glutamyl transferase and cholesterol concentrations were increased whereas bilirubin and albumin levels were decreased dose-dependently. Histological examination of the liver was characterized by accumulation of inflammatory cells around hepatocytes, and extended sinusoids. The histo-pathological alterations and oxidative damage observed in the liver of treated rats and occurrence of pathogenic species and metals in the RCLL may suggest possible impaired hepatic health in subjects with occupational or environmental exposure.

Tissue distribution and oral exposure risk assessment of heavy metals in an urban bird: magpie from Central Iran

Direct ingestion of soil and/or soil attached to the food items is a potential rout for wildlife exposure to contaminants. In this study, bioaccumulation of five heavy metals (HMs) in internal tissues of an urban bird (Pica pica) collected from Aran-O-Bidgol City, Central Iran and their related soil were investigated. A total of 15 magpie specimens were collected in autumn 2013 and then their internal tissues were digested using a mixture of HNO₃ and H₂O₂, and finally, concentrations of HMs were detected by ICP-OES. In addition, in order to show level of HM exposure risk to magpie, an exposure risk assessment was modeled. Results indicated that HMs were accumulated as follows: liver > kidney > muscle. Zn and Cu were significantly higher in magpie's tissues collected from agricultural site; on the other hand, Pb and Cd were significantly higher in industrial site (p < 0.05). Level of Cd in male's livers (2.11 μg/g dw) was significantly higher than in females (1.85 μg/g dw) (p < 0.05). Levels of Cd, Pb, and Ni in liver, muscle, and kidney, respectively, were significantly higher in adults than in subadults (p < 0.05). Soil exposure doses of all HMs were lower than tolerable daily intake (Zn 4.35, Cu 1.34, Ni 5.65, Pb 0.35, and Cd 0.53). The calculated hazard quotations (HQs) for HMs were as follows: Pb > Zn > Cu > Ni > Cd and for all HMs were at no risk level (HQ < 1). The amounts of hazard index for three sites were as follows: urban (1.032) > agriculture (0.943) ≥ industry (0.941) and only for urban area was at low risk (1 < HQ < 2). It seemed that birds living in a safe environment and/or HM contaminations in soil separately had no negative effects on magpies. We can also suggest that low levels of HMs in magpie's tissues can be due to low levels of HMs in soil.

Non-invasive hair sampling of Neotropical otters

Abstract: Sampling wild animal populations using non-invasive techniques is advised when dealing with threatened species. Hair samples provide ecological information like species and individual identification. However, hair trapping is scarcely used in otters, due to their aquatic habits. Most studies are with captive individuals, so there is the need to test non-invasive hair trapping methods in otters in the wild. The aim of this study was to develop a simple and cost-effective method to collect hair from otter species in a non-invasive way. The study was carried out in the Paranapanema River, São Paulo State, Brazil, with the Neotropical otter (Lontra longicaudis Olfers, 1818), a protected species. Hair traps (wooden sticks and tree roots with adhesive tape or wax bands) were set during six nights on river banks, otter trails and scent-marking sites. Traps were baited with otter fresh spraints from other river locations. From the 23 traps, 10 (43.7%) were successful in collecting otter hairs, mostly guard-hair. The sticks were much more efficient than the roots at capturing otter hair (70.6.% vs. 0%) as well as adhesive tape when compared to wax (71.4% vs. 0%). Method simplicity and efficiency suggest that it can be a cost-effective way for collecting otter hairs without the need for capturing individuals. This method can be used for: assessment of local otter distribution; collecting otter hair samples for sex and individual identification (by molecular analysis), trophic ecology (by isotopic analyses), ecotoxicology (by contamination analysis) or behaviour ecology (by hormonal and stress levels analysis). More trapping campaigns should be implemented to further test the method's efficiency.

The application of illite supported nanoscale zero valent iron for the treatment of uranium contaminated groundwater

In this study, nanoscale zero valent iron I-NZVI was investigated as a remediation strategy for uranium contaminated groundwater from the former Cimarron Fuel Fabrication Site in Oklahoma, USA. The 1 L batch-treatment system was applied in the study. The result shows that 99.9% of uranium in groundwater was removed by I-NZVI within 2 h. Uranium concentration in the groundwater stayed around 27 μg/L, and there was no sign of uranium release into groundwater after seven days of reaction time. Meanwhile the release of iron was significantly decreased compared to NZVI which can reduce the treatment impact on the water environment. To study the influence of background pH of the treatment system on removal efficiency of uranium, the groundwater was adjusted from pH 2-10 before the addition of I-NZVI. The pH of the groundwater was from 2.1 to 10.7 after treatment. The removal efficiency of uranium achieved a maximum in neutral pH of groundwater. The desorption of uranium on the residual solid phase after treatment was investigated in order to discuss the stability of uranium on residual solids. After 2 h of leaching, 0.07% of the total uranium on residual solid phase was leached out in a HNO₃ leaching solution with a pH of 4.03. The concentration of uranium in the acid leachate was under 3.2 μg/L which is below the EPA's maximum contaminant level of 30 μg/L. Otherwise, the concentration of uranium was negligible in distilled water leaching solution (pH = 6.44) and NaOH leaching solution (pH = 8.52). A desorption study shows that an acceptable amount of uranium on the residuals can be released into water system under strong acid conditions in short terms. For long term disposal management of the residual solids, the leachate needs to be monitored and treated before discharge into a hazardous landfill or the water system. For the first time, I-NZVI was applied for the treatment of uranium contaminated groundwater. These results provide proof that I-NZVI has improved performance compared to NZVI and is a promising technology for the restoration of complex uranium contaminated water resources.

The role of density-dependence regulation in the misleading effect of the Aznalcollar mining spill on the booted eagle fecundity

The aim of this study was to assess the exposure and potential effects of the toxic elements released by the Aznalcollar spillage on the fecundity of the booted eagle (Hieraetus pennatus) population of Doñana National Park. We measured As, Cd, Cu, Pb, Zn, Sb and Tl levels in the blood of 24 individuals after the accident and also used data of reproductive performance of the species from 1976 to 2000. While As, Sb and Tl were below their detection limits and only 3 samples were above detection limit for Cd (0.02-0.04μg/dl), mean levels of Cu, Zn and Pb (μg/dl) were found to be 38.736, 532.937 and 0.719, respectively, in fledglings; and 66.112, 652.571 and 1.825, respectively, in adults. These levels were higher in adults, but they did not differ significantly between age classes and were at safe levels. In addition, a positive relationship between relative fecundity and the combination of Cu, Zn and Pb was observed. Following the mining spill, the mean population fecundity was lower (0.536 fledglings per pair in the population) than before (1.093). However, the decrease in fecundity over time was also related to the increase of breeding pairs, suggesting a density-dependent regulation and nullifying the mining spillage effect. Thus, although raptors have proved to be highly valuable biomonitors of environmental pollution, we must be especially cautious and go beyond the apparent effects that sometimes we quickly believe to detect, leading us to reach mistaken conclusions that could affect our management plans.

Evaluation of some factors influencing on variability in bioaccumulation of heavy metals in rodents species: Rombomys opimus and Rattus norvegicus from central Iran

In the present study, the effects of sex, age, nutritional status, and habitat use on hair and internal tissue concentrations of some trace metals (Zn, Cu, Ni, Pb and Cd) in brown rat (Rattus norvegicus) and great gerbil (Rhombomys opimus) from Aran-O-Bidgol City in Central Iran were investigated. Five sampling stations in different land-uses were selected for the study. Concentrations of Cd and Pb in liver and whole body concentration as well as concentration of Zn in hair of male rats were significantly higher than females. A significantly higher concentration was only observed for Pb in kidney of male gerbils than females. In numerous cases, age had significantly negative correlations with concentration of metals in different tissues of both species, and was only significantly (and positively) correlated with the concentration of Cd in kidney and Zn in liver of gerbils. This finding may indicate that the early neonatal age is a critical period for metals accumulation. The relationships between nutritional status and metal concentrations for both species were negative, which can be ascribed to the weight-specific metabolic rate that cause to a relatively low uptake of metals per unit of body weight. No significant differences were observed for soil metals concentrations in different sites. So, this suggests that the influence of life history, microhabitat use and foraging behavior did significantly influence on inter and intra specific variation of metals concentration in small mammals. Our observations suggest that hair cannot be used alone for monitoring exposure of metals.

Monitoring Lead (Pb) Pollution and Identifying Pb Pollution Sources in Japan Using Stable Pb Isotope Analysis with Kidneys of Wild Rats

Although Japan has been considered to have little lead (Pb) pollution in modern times, the actual pollution situation is unclear. The present study aims to investigate the extent of Pb pollution and to identify the pollution sources in Japan using stable Pb isotope analysis with kidneys of wild rats. Wild brown (Rattus norvegicus, n = 43) and black (R. rattus, n = 98) rats were trapped from various sites in Japan. Mean Pb concentrations in the kidneys of rats from Okinawa (15.58 mg/kg, dry weight), Aichi (10.83), Niigata (10.62), Fukuoka (8.09), Ibaraki (5.06), Kyoto (4.58), Osaka (4.57), Kanagawa (3.42), and Tokyo (3.40) were above the threshold (2.50) for histological kidney changes. Similarly, compared with the previous report, it was regarded that even structural and functional kidney damage as well as neurotoxicity have spread among rats in Japan. Additionally, the possibility of human exposure to a high level of Pb was assumed. In regard to stable Pb isotope analysis, distinctive values of stable Pb isotope ratios (Pb-IRs) were detected in some kidney samples with Pb levels above 5.0 mg/kg. This result indicated that composite factors are involved in Pb pollution. However, the identification of a concrete pollution source has not been accomplished due to limited differences among previously reported values of Pb isotope composition in circulating Pb products. Namely, the current study established the limit of Pb isotope analysis for source identification. Further detailed research about monitoring Pb pollution in Japan and the demonstration of a novel method to identify Pb sources are needed.

In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.)

Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.

Liver histological changes and lipid peroxidation in the amphibian Ambystoma mexicanum induced by sediment elutriates from the Lake Xochimilco

Lacustrine sediments accumulate pollutants that input from the lake watershed and can be released to the water column by sediment resuspension; thus, pollutants can change their bioavailability and exert adverse effects to aquatic biota. Shallow-urban lakes are particularly susceptible to receive pollutants from urban discharges and sediment resuspension. Lake Xochimilco, in Mexico City, an urban-shallow lake, faces multiple problems: urban sprawl, overexploitation of aquifers, drying of springs, discharge of wastewater from treatment plants, and sediment resuspension. The aquatic biota living in this ecosystem is continuously exposed to the release of pollutants from the sediments. We assessed the risk that pollutants released from sediments from Lake Xochimilco, Touristic (TZ) and Agriculture zone (AZ), can exert on a native amphibian species of the lake (Ambystoma mexicanum) through exposure bioassays to sediment elutriates. We evaluate alterations in the amphibian by three approaches: biochemical (level of lipid peroxidation, LPO), cellular (ultrastructure) and the liver histology of A. mexicanum and we compare them with a batch control. Additionally, we assessed heavy metals (Pb, Cd and Hg) in elutriates. Elutriates from TZ showed the highest concentrations of the metals assessed. Organisms exposed to sediment elutriates from either study sites showed higher LPO values than control organisms (p<0.05). Organisms exposed to elutriates from the TZ showed the most conspicuous damages: hepatic vasodilation of sinusoids, capillaries with erythrocytes, leukocyte infiltration and cytoplasmic vacuolation in hepatocytes. The biological responses assessed reflected the risk that faces A. mexicanum when is exposed for prolonged periods to sediment resuspension in Lake Xochimilco.

Testicular damage and farming environments - An integrative ecotoxicological link

The exposure to agrochemicals during farming activities affects the function of the reproductive system, as revealed by the increasing worldwide evidence of male infertility amongst farmers. The main objective of this study was to untangle the link between agricultural practices and male reproductive impairment due to chronic exposure to xenobiotics (such as agrochemicals) in conventional and organic farming environments. For this purpose, male wild mice (Mus musculus) populations from sites representing two distinct farming practices (conventional and organic farming systems) were used as bioindicators for observable effects of testicular damage, namely on a set of histological and cellular parameters: (i) relative volumetric density of different spermatogenic cells and interstitial space; (ii) damage in the seminiferous tubules and (iii) apoptotic cells in the germinal epithelium. Results showed that mice from the conventional farming site bioaccumulated higher Pb hepatic loads, while mice from the organic farming site tend to bioaccumulate higher Cd hepatic loads. In general, for the analyzed testicular damage related parameters, mice from the organic farming site showed a similar performance than mice from the reference site. Mice from the conventional farming site stood out not only by underperforming in most studied parameters, while displaying an association between Pb hepatic loads and the observed testicular structural and functional disruption, but also by the increased stress index (Integrated Biomarker Response value). This study highlights the potential damaging effects of conventional farming practices on testicular structure and function, under natural conditions, raising concern about ensuing fertility risks for farmers.

In situ experiments to assess effects of constraints linked to caging on ecotoxicity biomarkers of the three-spined stickleback (Gasterosteus aculeatus L.)

The aim of this study was to evaluate the effects of caging constraints on multiple fish biomarkers used during ecotoxicological studies (biometric data, immune and antioxidant systems, and energetic status). Two of these constraints were linked to caging: starvation and fish density in cages, and one in relation to the post-caging handling: a short transport. Three in situ experiments were conducted with three-spined sticklebacks (Gasterosteus aculeatus). The first experiment compared the effects of three densities (low, medium, and high). The second experiment compared effects of starvation in fish fed every two days with fish that were not fed. Finally comparisons between sticklebacks which have suffered a short car transport after caging and sticklebacks killed without preliminary transport were made. The lack of food had no effect on fish energetic reserves but negatively affected their condition index and their immune system. Transport and high density induced oxidative stress, defined as an overproduction of reactive oxygen species and a stimulation of the antioxidant system. These two constraints also harmed the leucocyte viability. In order not to have any impact on ecotoxicity biomarkers during in situ experiments, it is preferable to decrease fish density in cages, prevent transport before dissections, and feed fish when the caging lasts more than two weeks.

Fur: A non-invasive approach to monitor metal exposure in bats

This paper presents a novel assessment of the use of fur as a non-invasive proxy to biomonitor metal contamination in insectivorous bats. Concentrations of metals (cadmium, copper, lead and zinc) were measured using ICP-MS in tissues (kidneys, liver, stomach and stomach content, bones and fur) obtained from 193 Pipistrellus pipistrellus/pygmaeus bats. The bats were collected across a gradient of metal pollution in England and Wales. The utility of small samples of fur as an indicator of metal exposure from the environment was demonstrated with strong relationships obtained between the concentrations of non-essential metals in fur with concentrations in stomach content, kidneys, liver and bones. Stronger relationships were observed for non-essential metals than for essential metals. Fur analyses might therefore be a useful non-invasive proxy for understanding recent, as well as long term and chronic, metal exposure of live animals. The use of fur may provide valuable information on the level of endogenous metal exposure and contamination of bat populations and communities.

Accumulation of heavy metals and As in liver, hair, femur, and lung of Persian jird (Meriones persicus) in Darreh Zereshk copper mine, Iran

Rodents frequently serve as bioindicator to monitor the quality of the environment. Concentrations of 11 elements (Cd, Co, Ti, Fe, Mn, Cu, Sb, As, Sr, Ni, and Cr) were investigated and compared in liver, hair, femur, and lung of the Persian jird (Meriones persicus) from Darreh Zereshk copper mine, Iran. Metals were determined in different tissues of 39 individuals of Persian jird, collected by snap trap in 2014 from five areas of Darreh Zereshk copper mine. Samples were prepared by wet digestion method, and the contents of elements were analyzed with ICP-OES (VARIAN, 725-ES) instrument. Cadmium, Sb, and Co were below the limit of detection, and Mn and As were found only in hair and liver tissues. We detected the highest concentration of Cu, As, Ti, Fe, Mn, Cr, and Ni in hair in comparison with other tissues. Significant higher levels of Ti in femur and hair; Fe in liver and hair; Mn in liver; As in hair; Sr in lung; Cr in lung, hair, femur, and liver; Cu in femur; and Ni in liver and lung tissues were observed in females. Nearly all element concentrations in the tissues of Persian jird from flotation site, Darreh Zereshk and Hasan Abad villages and leaching site (mining areas) were higher than those from tailing dump site (reference site). We found the highest concentrations of As in liver and hair; Ni and Cr in liver, hair, and lung; and Sr in lung and hair tissues of Persian jird in leaching site. We tried to specify the status of elements before fully exploitation of Darreh Zereshk copper mine by using bioindicator species. Based on our achievements, initial activities did not strongly pollute the surrounded environment of the mine. The high abundance of Persian jird as well as their several proper features makes them a suitable species for biomonitoring programs especially for further studies will be performed after full exploitation of Darreh Zereshk copper mine.

Pollutant exposure at wastewater treatment works affects the detoxification organs of an urban adapter, the Banana Bat

The Banana Bat, Neoromicia nana, exploits pollution-tolerant chironomids at wastewater treatment works (WWTWs). We investigated how pollutant exposure impacts the detoxification organs, namely the liver and kidney of N. nana. (i) We performed SEM-EDS to quantify metal content and mineral nutrients, and found significant differences in essential metal (Fe and Zn) content in the liver, and significant differences in Cu and one mineral nutrient (K) in the kidneys. (ii) We performed histological analysis and found more histopathological lesions in detoxification organs of WWTW bats. (iii) We calculated hepatosomatic/renalsomatic indices (HSI/RSI) to investigate whole organ effects, and found significant increases in organ size at WWTWs. (iv) We quantified metallothionein 1E (MT1E), using Western Blot immunodetection. Contrary to predictions, we found no significant upregulation of MT1E in bats at WWTWs. Ultimately, N. nana exploiting WWTWs may suffer chronic health problems from sub-lethal damage to organs responsible for detoxifying pollutants.

Volcanogenic pollution and testicular damage in wild mice

Many evidences have surfaced the adverse effects of environmental pollutants on male reproduction. Volcanogenic pollution is understudied, although it is a well-known source of hazardous contaminants. This study aims to assess the effects of chronic exposure to volcanogenic pollution on wild mice testes by studying: (i) diameter of seminiferous tubules; (ii) relative volumetric density of different spermatogenic cells and interstitial space; (iii) damage in the seminiferous tubules and (iv) apoptotic level in the germinal epithelium. The mice from the polluted site showed higher levels of the selected heavy metals than those from the reference site. The mean diameter of seminiferous tubules and the relative volume occupied by spermatozoa and lumen in exposed mice were significantly lower than in the unexposed group. Contrarily, exposed mice showed a significantly higher relative volume occupied by interstitium, as well as, a higher degree of damage and a significantly higher number of apoptotic cells in the germinal epithelium. Results show that secondary manifestations of volcanic activity can pose a serious risk of testicular injury and therefore for male reproduction.