Maximum Hg Concentration Research Articles

Behavioral and biochemical patterns in the Andean highland macroinvertebrate Nectopsyche sp. after chronic mercury exposure

Environmental pollution by mercury (Hg) is of particular interest in Latin American countries like Ecuador, where artisanal and industrial gold mining has widely expanded. However, classic assessments, either based on water parameters or bioindicators, are not always effective in determining the effect of this type of pollutant on the ecological quality of the rivers. This study analyzed the behavioral and biochemical responses in benthic macroinvertebrate Nectopsyche sp. after sub-lethal Hg exposure emulating the maximum limits allowed by the current legislation in Ecuador (0.0002 mg L−1). Behavioral changes were significant, with an average decrease in the movement (measured as the number of strokes per 15 s of larvae) after 6 days of exposure to the maximum limit concentration of Hg. Furthermore, the antioxidant enzyme Glutathione S-Transferase activity significantly increased when exposed for 7 days to 0.0002 mg L−1 of Hg concentration. These results preliminarily proved that behavioral and biochemical patterns could function as biomarkers that efficiently identify ecological impairment caused by Hg, which would otherwise be neglected by a purely chemical-based or biomonitoring based on the presence/absence of macroinvertebrates type of assessment. Moreover, we demonstrate that the current limits allowed can impair aquatic life.

О СОДЕРЖАНИИ ртути в ДИКОРАСТУЩИХ ГРИБАХ (город Хабаровск и хАБАРОВСКий район)

The paper presents the results of research on mercury concentration in mushrooms collected in the Khabarovsk Territory, including the town, in the fall of 2022. The research shows that the mercury concentration in fruit body can widely vary dependent on the type and place of growth. Even for the same mushrooms type fruit bodies indicators can vary from several times to 2 orders. At this, the stems accumulate less mercury than the caps, and tubular mushrooms accumulate less mercury than lamellar ones. The study shows a surpass of maximum permissible concentration (MPC) for mercury index in more than half lamellar mushrooms, not revealed in tubular mushrooms. The maximum concentration of Hg (14 mg/kg of dry matter) and the maximum coefficient of biological absorption (45) were revealed for common meadow mushroom (Agaricus campestris), collected in the Khabarovsk downtown lawn. The other champignons there contained mercury 5–7 times less. The lowest mercury concentrations were found in polypore mushrooms. Concentration of mercury in them did not exceed 0.05 mg/kg of dry solids content, and the coefficient of biological absorption was in the range of 0.08–0.4.

Whiskers provide time-series of toxic and essential trace elements, Se:Hg molar ratios, and stable isotope values of an apex Antarctic predator, the leopard seal

In an era of rapid environmental change and increasing human presence, researchers need efficient tools for tracking contaminants to monitor the health of Antarctic flora and fauna. Here, we examined the utility of leopard seal whiskers as a biomonitoring tool that reconstructs time-series of significant ecological and physiological biomarkers. Leopard seals (Hydrurga leptonyx) are a sentinel species in the Western Antarctic Peninsula due to their apex predator status and top-down effects on several Antarctic species. However, there are few data on their contaminant loads. We analyzed leopard seal whiskers (n = 18 individuals, n = 981 segments) collected during 2018–2019 field seasons to acquire longitudinal profiles of non-essential (Hg, Pb, and Cd) and essential (Se, Cu, and Zn) trace elements, stable isotope (ẟ15N and ẟ13C) values and to assess Hg risk with Se:Hg molar ratios. Whiskers provided between 46 and 286 cumulative days of growth with a mean ~ 125 days per whisker (n = 18). Adult whiskers showed variability in non-essential trace elements over time that could partly be explained by changes in diet. Whisker Hg levels were insufficient (<20 ppm) to consider most seals being at “high” risk for Hg toxicity. Nevertheless, maximum Hg concentrations observed in this study were greater than that of leopard seal hair measured two decades ago. However, variation in the Se:Hg molar ratios over time suggest that Se may detoxify Hg burden in leopard seals. Overall, we provide evidence that the analysis of leopard seal whiskers allows for the reconstruction of time-series ecological and physiological data and can be valuable for opportunistically monitoring the health of the leopard seal population and their Antarctic ecosystem during climate change.

Syntrichia caninervis adapt to mercury stress by altering submicrostructure and physiological properties in the Gurbantünggüt Desert

Sewage and industrial waste discharges have been found to have a deleterious effect on plant growth and environmental safety through the accumulation of trace metal mercury (Hg) in soils. Although the effects of Hg on vascular plants have been reported in terms of enzyme activity, oxidative damage and physiology, few studies have been done on non-vascular plants. A simulation experiment including 7 Hg concentrations (0, 10, 20, 30, 40, 50, 75 µM) was conducted to investigate the influence of Hg stress on ultrastructure and physiological properties of biocrust moss Syntrichia. caninervis across 7 consecutive days. The results showed that the lowest lethal concentration of S. caninervis was 30 µM Hg. The mortality rate of the plants increased significantly with Hg concentrations. The ultrastructure did not change significantly at Hg concentration ≤ 20 µM, while exceeding which, cell walls began to separate, nuclei began to blur, and chloroplasts began to expand. The soluble sugars (SS), peroxidase (POD), and superoxide dismutase (SOD) activities increased initially and then decreased with the increase of concentration in the time gradient, with the largest values at 20 µM. The contents of malondialdehyde (MDA) and proline (Pro) increased with the increase of Hg concentration, both reached peak value at 50 µM. However, chlorophyll (Chl) contents continued to decrease along both the concentration and time gradients. Pearson correlation and principal component analysis showed that two principal components (PC1 and PC2) explained 73.9% of the variance in plant adaptation to Hg stress. SOD, POD, Chl, SS, and Pro all responded well to Hg in S. caninervis. Our study showed that Hg stress caused changes in ultrastructure and physiological metabolism of S. caninervis. 20 µM was the maximum concentration of Hg that biocrust moss S. caninervis can tolerate. S. caninervis mainly adopted two adaptation strategies related to exclusion and accumulation to reduce Hg stress.

Effect of Plant Growth-Promoting Bacteria on Biometrical Parameters and Antioxidant Enzymatic Activities of Lupinus albus var. Orden Dorado Under Mercury Stress.

Heavy metal contamination of soils is a large-scale environmental problem. It leads to significant disqualification of the territory, in addition to being a source of the potential risk to human health. The exposure of plants to mercury (Hg) generates responses in its growth and their oxidative metabolism. The impact of increasing concentrations of Hg on the development of Lupinus albus var. Orden Dorado seedlings has been studied, as well as the plant’s response to the maximum concentration of Hg that allows its development (16 μg ml–1). The result shows that only the inoculum with plant growth promoting bacteria (PGPB) allows the biometric development of the seedling (root length, weight, and number of secondary roots) and prevents the toxic effects of the heavy metal from aborting the seedlings. Specifically, treatments with strains 11, 20 (Bacillus toyonensis), 48 (not determined), and 76 (Pseudomonas syringae) are interesting candidates for further PGPB-assisted phytoremediation trials as they promote root biomass development, through their PGPB activities. The plant antioxidant response has been analyzed by quantifying the catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) enzyme activity in the root, under 16 μg ml–1 of HgCl2 and different PGPB treatments. Results show that, although Hg stress generally induces enzyme activity, strains 31 and 69I (Pseudomonas corrugata) and 18 and 43 (Bacillus toyonensis) can keep SOD and APX levels close to those found in control without Hg (p < 0.01). Strain 18 also shows a significant reduction of GR to control levels without Hg. The present work demonstrates the benefit of PGPB treatments in situations of high Hg stress. These findings may be a good starting point to justify the role of PGPB naturally isolated from bulk soil and the rhizosphere of plants subjected to high Hg pressure in plant tolerance to such abiotic stress conditions. More studies will be needed to discover the molecular mechanisms behind the phytoprotective role of the strains with the best results, to understand the complex plant-microorganism relationships and to find effective and lasting symbioses useful in bioremediation processes.

Environmental Survey of the Distribution and Metal Contents of Pteris vittata in Arsenic-Lead-Mercury-Contaminated Gold Mining Areas along the Bone River in Gorontalo Province, Indonesia.

In this paper, we report ecological and environmental investigations on Pteris vittata in the As–Pb–Hg-polluted Bone River area, Gorontalo Province, Indonesia. The density distribution of P. vittata decreases from around the artisanal and small-scale gold mining (ASGM) site to the lower reaches of the Bone River, and it is rarely found near Gorontalo City. The maximum concentrations of As, Hg, and Pb recorded in the soil samples were 401, 36, and 159 mg kg−1, respectively, with their maximum concentrations in P. vittata recorded as 17,700, 5.2, and 39 mg kg−1, respectively. Around the ASGM sites, the concentrations of As, Pb, and Hg in P. vittata were highest in the study area. These data suggest that P. vittata, a hyperaccumulator of As, may be useful as a bioindicator for assessing environmental pollution by Pb and Hg.

Metal Distributions and Human Health Risk Assessments on Waters in the Huixian Karst Wetland, China

The concentrations of nine metals (As, Cr, Al, Cu, Pb, Zn, Ni, Mn, and Hg), in 23 water samples collected from four main types of water (well, surface river, subterranean stream and blue hole), in the Huixian karst wetland were determined and analyzed to investigate their distributions and health risks. A multivariate statistical analysis was used to study the distribution characteristics of the metals. A human health risk assessment model was developed to assess the health risks. The results found that the mean concentrations of metals in water from the Huixian karst wetland were in the order:Al > Mn > Zn > Cr > Ni > As > Hg > Cu > Pb. The maximum concentrations of Hg (1.08 μg·L-1) in the well water, Hg (0.78 μg·L-1) and Mn (259.00 μg·L-1) in the surface river water, and Hg (0.47 μg·L-1) and Al (300.00 μg·L-1) in the blue hole water all exceeded the corresponding standard limits. The metal concentrations in the subterranean stream samples were all within the regulated limits. For the nine metals, the well water and the subterranean stream water qualities were better than those of the surface river and the blue hole. The results of the multivariate statistical analysis showed that the concentrations of Cr, Ni, Cu, and Zn in the well water were mainly related to the regional geological background, while the concentrations of Al and Pb in the blue hole water were mainly affected by pyrite mining and residential activities. The concentrations of As and Mn in rivers may be affected by tourism activity, aquaculture and river sediments. The results of the health risk assessment on water through the drinking and skin penetration pathway indicated that the total health risks order was:well > subterranean stream > blue hole > surface river. The total health risks values of well water as drinking water for adults (6.11×10-5 a-1) and children (6.67×10-5 a-1) exceeded the maximum allowance level (5.0×10-5 a-1). Cr was the main metal element that causes carcinogenic risks. For drinking water safety, the concentrations of Hg and Cr in well water should be controlled before drinking.

Toxic Metal Concentrations of Human Hair in Downstream of ASGM Sites in Bone Bolango Regency, Gorontalo Province, Indonesia

Bone Bolango is a regency that has a lot of ASGM sites that use elemental mercury for gold processing compare to the other regencies in Gorontalo province. This activity produces waste containing hazardous substances dumped in Bone River. This river has been used to support human life also a source of drinking water in the city of Gorontalo. This research aims to investigate the source of toxic metal in the human hair of Tulabolo ASGM sites in Bone Bolango Regency, Gorontalo Province, Indonesia. Hair samples were collected from the inhabitants who are living near Bone River. Total of toxic element concentration in the samples was analyzed by using Particle-induced X-ray emission (PIXE) which derives from Iwate Medical University. The maximum concentration of Hg, As, and Pb are 12.3 µg/g, 11.1 µg/g, and 13.5 µg/g, respectively. Those results show that Hg, As, and Pb are in danger level. Also, the results reveal that natural and anthropogenic sources have regionally polluted the areas.

Toxic and essential trace element concentrations in fish species in the Lower Amazon, Brazil

The Lower Amazon region (Western Pará, northern Brazil) is greatly affected by mining exploitations (particularly artisanal gold mines) and other industrial and intensive agricultural activities with potentially strong impacts on aquatic ecosystems. Although such impacts include contamination with various toxic elements, to date only the effects of Hg have been considered. In this study, toxic and trace element concentrations were determined in the flesh of 351 fish specimens, including detritivores (Acarí, Pterygoplichthys pardalis), omnivores (Piranha, Pygocentrus nattereri; Pirarucu, Arapaima sp.) and carnivores (Caparari, Pseudoplatystoma fasciatum; Tucunaré, Cichla ocellaris), during the dry and wet seasons in 2015 and 2016. The range of concentrations of toxic element residues were 2–238 μg/kg fresh weight for As, 1–77 μg/kg for Cd, 4–1922 μg/kg for Hg and 1–30 μg/kg for Pb. Only the maximum concentrations of Hg established in the Brazilian legislation for fish destined for human consumption (0.5 mg/kg) were exceeded (in 16% of carnivorous species). The large between-species and seasonal differences observed for all these toxic elements are probably related to the seasonal behaviour and dietary habits of the different fish species. By contrast, essential trace element concentrations were low and not related to seasonal or dietary factors, and the observed differences may be at least partly related to the metabolism of each species. The associations between Hg and the essential trace elements Se, Fe, Co and Mn deserve special attention, as these trace elements may play a role in Hg cycling and methylation and merit further evaluation with the aim of reducing Hg toxicity in aquatic environments.

Evaluation of heavy metals (Cd, Cr, Hg, Ni, As, and Pb) concentration in salt samples of Lake Urmia, Iran

ABSTRACT Heavy metals are one of the environmental pollutants that human exposure to them can cause chronic diseases. In most people, food is one of the most important sources of heavy metals. Therefore, the evaluation of heavy metals residues in various food samples and food additives like salt is of great importance. In this study, 30 salt samples were collected from 30 different locations of Lake Urmia and analysed with inductively coupled plasma-atomic emission spectroscopy to assess the contamination of heavy metals in them. In this method, the analytes were extracted with two chelating agents. The maximum concentrations of Cd, Cr, Hg, Ni, As, and Pb in the evaluated salt samples were 40, 541, 261, 464, 38, and 254 ng g–1, respectively. Comparison of the obtained results with the Codex maximum residue limits of heavy metals in the edible salt indicated that only in two cases of the studied salt samples the concentrations of metals exceeded the recommended levels (in one sample the concentration of Cr and in another sample, the concentration of Hg). Considering the outcomes of this study and the adverse effects of heavy metals residues on human health, continuous monitoring of their levels in the salt samples of Lake Urmia is highly recommended.

Trace metal biomonitoring in the east Gippsland Lakes estuary using the barnacle Amphibalanus variegatus and mussel Mytilus edulis.

The Gippsland Lakes estuary, a Ramsar listed wetland, in Victoria, Australia, is an area of potential concern for metal pollution due to influxes of human population and associated anthropogenic activities. A biomonitoring exercise was undertaken where the concentrations of 9 metals (Cr, Fe, Cu, Zn, As, Se, Ag, Cd and Hg) were analysed in the soft tissue of two common sessile invertebrates: the mussel Mytilus edulis and the barnacle Amphibalanus variegatus from 6 locations on two different occasions throughout the Gippsland Lakes estuary. A salinity gradient exists in the Lakes, from seawater at Lakes Entrance in the east, decreasing down to < 10 PSU in the west at Lake Wellington during times of rainfall, which is a major factor governing the growth and distribution of both species. Dissolved metal levels in general were low; however, Cu at most sites exceeded the 90% trigger values, while all Zn concentrations exceeded the lowest 80% trigger values of the ANZECC marine water quality guidelines for environmental health. Elevated levels of Cu and Zn were found particularly in barnacles at some sites with environmental contamination due to leaching from anti fouling paints and sacrificial zinc anodes. Elevated levels of Ag and Cd were found in mussels at the Hollands Landing site, which is immediately adjacent to a boat ramp, and Cd and Ag at this site are suspected to originate from inland anthropogenic sources. Concentrations of As in M. edulis across all 6 sites in both sampling periods had mean wet weight As concentrations exceeding the maximum level stated in the FSANZ guidelines. A. variegatus contained elevated levels of Hg especially at the North Arm site with a maximum of 13.6 μg Hg/g dry wt., while A. variegatus also showed temporal changes in Hg concentrations across sites. The maximum Hg concentration found in Mytilus edulis was 1.49μg Hg/g dry wt. at the Hollands Landing site. Previous contaminant studies of biota in the Lakes have targeted sampling of singular predatory or migratory species, such as Black Bream (Acanthopagrus butcheri) and the Burrunan dolphin (Tursiops australis). This is the first biomonitoring study conducted on sessile organisms to assess metal contamination in the system.

The use of hair as a proxy for total and methylmercury burdens in polar bear muscle tissue

Polar bears (Ursus maritimus) are an ecologically important species in the Arctic, whose health, and that of the people whose livelihoods depend on them, are increasingly affected by climate change and the bioaccumulation of contaminants such as mercury (Hg). Although methylmercury (MeHg) is the toxic form of Hg that biomagnifies up food webs, risk assessment studies typically only report on total Hg (THg) concentrations because it is cheaper to quantify. Furthermore, hair is commonly analysed for THg in polar bear as well as human risk assessment studies because it is relatively non-invasive to collect, yet we know little of how THg and MeHg concentrations differ between hair and muscle tissues. In this study, we quantified THg and MeHg concentrations in hair and muscle from 44 polar bears (24 sub-adults: 9 females, 15 males; 18 adults: 5 females, 13 males, and 2 males of unknown age group), harvested in 2015 and 2016 from four subpopulations in Nunavut, Canada (Davis Strait, n = 3; Gulf of Boothia, n = 8; Baffin Bay, n = 15; Foxe Basin, n = 18). We found only moderately positive correlations (0.4 ≤ r ≤ 0.5) between THg concentrations in hair and THg and MeHg concentrations in muscle. Further, 75% and 88% of THg was MeHg in hair and muscle, respectively. High concentrations of THg in hair - 71% of the samples were above the suggested neurochemical no observed effect level for polar bears - suggest some of the bears may be adversely affected by Hg-related health effects. Despite this, all MeHg concentrations in muscle (0.1 to 0.4 mg/kg (wet weight, ww)) were below the consumption maximum Hg concentration of 0.5 mg/kg (ww) set by Canadian health authorities.

Analysis of Heavy Metals in Foodstuffs and an Assessment of the Health Risks to the General Public via Consumption in Beijing, China.

Consumption of foodstuffs is the most likely route for human exposure to heavy metals. This study was designed to investigate the toxic metals (cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), and mercury (Hg)) concentrations in different foodstuffs (cereals, vegetables, fruits, fish, and meat) and then estimate the potential health risks of toxic metals via consumption to the local residents in Beijing, China. Most of the selected toxic metal levels in the foodstuffs were lower than the maximum allowable concentrations of Pb, Cr, Cd, As, and Hg for Chinese foodstuffs recommended in the China National Food Safety Standard. The health risks associated with the toxic metals Pb, Cr, Cd, As, and Hg were assessed based on the target hazard quotients (THQs) proposed by the United States Environmental Protection Agency (US EPA). The THQ values of the foodstuffs varied and were 0.03–0.29 for Cr, 0.02–0.23 for Pb, 0.01–0.33 for Cd, 0.01–0.06 for As, and 0.00–0.04 for Hg, not exceeding the maximum level of 1. The total THQ (TTHQ) values were 0.88 for vegetables, 0.57 for cereals, 0.46 for meat, 0.32 for fish, and 0.07 for fruits. This indicates that the risk contribution from vegetable intake (38.8%) was significant in comparison to that from other foodstuffs. The TTHQ values were 0.96 for Cr, 0.54 for Pb, 0.50 for Cd, 0.19 for As, and 0.09 for Hg, suggesting that Cr was a major risk contributor (41.7%) for the local residents of Beijing, which should attract great attention. However, the THQ/TTHQ values were all below 1, suggesting no health risks to the local population through consumption. Furthermore, dietary weekly intakes (WIs) were also calculated and the values were all lower than the proposed limit of Provisional Tolerable Weekly Intakes (PTWI) established by the the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). This suggests no additional health risks as well as consistency with the THQ results.

Heavy metal pollution and health risk assessment of agricultural soil near a smelter in an industrial city in China

ABSTRACTTo assess heavy metal pollution and human health risk, a total of 28 topsoil samples were collected during four seasons from seven agricultural soil sites near a famous smelter in Jiyuan, China. The maximum concentrations of Cd, Pb, Hg, As, Zn, Cu, Ni, and Cr were 26.00, 2601.00, 3.29, 65.00, 410.00, 156.30, 54.80, and 73.60 mg kg−1, respectively. Compared with the sampling site nearest to the smelter, the concentrations of six metals at the farthest site were decreased significantly (P < 0.05). All sites were heavily contaminated, with Nemerow index (P) >3.0, and all sites had very high ecological risks related to Cd and Hg. The non-carcinogenic risk for children (based on combined exposure to the eight metals) was above the safety level. The carcinogenic risk of As for adults (8.98 × 10–6) and children (1.49 × 10–5) exceeded the acceptable level (1 × 10–6). Results suggest a serious health risk in the polluted areas, particularly for children.Abbreviation Cd: Cadmium; Pb: Lead; Hg: Mercury; As: Arsenic; Zn: Zinc; Cu: Copper; Ni: Nickel; Cr: Chromium; P: Nemerow index; RI: Potential ecological risk index; Ei: Monomial potential ecological risk of a specific heavy metal; HI: non-carcinogenic hazard index; CR: Carcinogenic risk; TN: Total nitrogen; TP: Total phosphorus; OM: Organic matter; MC: Moisture content; ADD: Average daily dose

Pollution of the Uglovoy Bay with heavy metals and petroleum products during february 2010–2016

We analyzed the pollution of Uglovoy bay with heavy metals and petroleum products during 2015–2016. According to maximum allowable concentrations of Mn, Fe, Cu, Ni, Hg, As, Pb, Cd, and petroleum products, we identified an area of hypoxia developing at the north-eastern coast of the bay, with heavy metal accumulation in the dissolved form. We concluded that the river is the main source of pollutants in this bay, and surveys of ice cores showed a high degree of heavy metal accumulation. Although ice sheets accumulate contaminants, these are released into water. Herein, we provide an estimate of water pollution at the entrance to the Uglovoy bay with heavy metals and petroleum products over the years 2010–2016.

Spatial Attenuation of Mining/Smelting-Derived Metal Pollution in Sediments From Tributaries of the Upper Han River, China

Spatial variations in contaminant distribution in river sediments are useful for pollutant diagnosis. This study investigated 18 metals/metalloids (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sn, Tl, U, V, Zn, and Hg) in sediments of rivers impacted by Sb and Hg mining/smelting activities in headwater catchments of the Han River Basin, China. Source and pollution assessments of the metals were examined based on their spatial variations. The results showed that sediment concentrations of Cu, Cr, Tl, U, Pb and typically, Ag, Mo, Sb, and Hg were generally elevated. However, their concentrations decreased from upstream to downstream along the river gradient. By combining their spatial variations with the results of multivariate analyses, it was deduced that the elevated concentrations were due to mining/smelting activities. At downstream sites, all elevated concentrations decreased to near background levels, except for those of Hg and Sb. The maximum concentrations of Hg and Sb in the river sediments, which were two- to three-orders of magnitude higher than the reference values, are still considered to pose very high potential ecological risks.

Effect of body length, trophic position and habitat use on mercury concentrations of sharks from contrasted ecosystems in the southwestern Indian Ocean

The non-essential metal mercury (Hg) can have deleterious effects on health of organisms, and tends to bioaccumulate with age in long-lived organisms and to biomagnify along food webs. Because elasmobranchs are fished for human consumption and their Hg levels are frequently above the maximum Hg concentration recommended for fish consumption, understanding the drivers of Hg concentration is of considerable interest. Total Hg concentrations were analysed in muscle tissues of 14 shark and 2 batoid species (n = 339 individuals) sampled across multiple habitats (coastal, open ocean and bathyal) in the southwestern Indian Ocean. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) were analysed to assess whether relative trophic position and foraging habitats affected Hg concentrations. Hg concentrations increased with δ15N and body length, highlighting the mechanisms of bioaccumulation and biomagnification in relation with the trophic position and size of the individuals. Habitats where elasmobranchs were collected also affected their Hg concentrations. Bathyal sharks had high Hg concentrations that were almost similar to those of oceanic species, despite their lower relative trophic position. Higher bioavailability of Hg due to its enhanced methylation in deeper waters was considered as the most likely explanation for this result. These results highlight that multiple factors contribute to mercury accumulation in elasmobranchs.

Analysis of Toxic and Essential Elements in the Blood and Feathers of Humboldt Penguins (Spheniscus humboldti) at Punta San Juan, Peru

Whole blood, serum, and feather samples from 29 Humboldt Penguins ( Spheniscus humboldti) at the Punta San Juan Marine Protected Area, Peru, were analyzed for 55 toxic and essential elements by using inductively coupled plasma mass spectrometry. Mercury (Hg) was analyzed by cold vapor atomic fluorescence. Maximum Hg concentrations in serum (0.0056 mg/g), whole blood (0.297 mg/kg), and feathers (1.8 mg/kg dry weight) were at levels generally not considered to cause health impairment. Of the elements analyzed, only eight (aluminum, calcium, iron, Hg, potassium, magnesium, sodium, and zinc) were detected in serum. These elements, plus selenium and titanium, were also quantifiable in whole blood. Feather analysis detected quantifiable values for the elements found in serum, plus arsenic, boron, barium, copper, manganese, and titanium. Results indicate this important breeding population of endangered penguins did not appear to be exposed to environmental elemental contaminants at levels detrimental to health and reproductive success. However, identification of measurable concentrations of toxic elements at low levels underscores the need for continued environmental monitoring, particularly in the face of expanding regional human populations and industrial growth. These results provide important reference data for temporospatial monitoring of this and other penguin populations.

Mercury Pollution of Lake Imandra Sediments, the Murmansk Region, Russia

Research on the chemical composition of Lake Imandra sediments (including mercury) was carried out. Lake Imandra is known to be the largest one in the Murmansk region, North-West of Russia. It is the subject of intense pollution by the industrial enterprises and municipal wastewater. It was established that chalcophilic Hg metal, being a high-toxic and dangerous one for the lake ecosystem, entered the lake due to activities of apatite–nepheline and copper–nickel industries. In the vertical Hg distribution, within sediments of the stations which were close to the drainage of apatite–nepheline deposit development, subsurface maximum of sediment cores from 0.6 up to 2.3 μg/g at the depths from 7 up to 14 cm was marked. That was ten times higher than the average background content (0.044 μg/g). These values were higher up to an order of magnitude than the Interim freshwater sediment quality guidelines (ISQG) and 5 times higher than the Probable effect level (PEL) for Hg according to Canadian Sediment Quality Guidelines for the Protection of Aquatic Life (2018) ( http://st-ts.ccme.ca/en/index.html ). The Bolshaya Imandra should be classified as “Class III” with the marked contamination according to the Environmental Classification System of the Norwegian Pollution Control Authority (Classification of environmental quality in fjords and coastal waters. A guide. Norwegian Pollution Control Authority, 1997). Hg content was in a wide range from 0.02 up to 1.0 μg/g in the surface of 1-cm sediment layer. The maximum Hg concentrations were confined to the water areas of the effluents from apatite–nepheline and copper–nickel industries.

Mercury contamination in bats from the central United States

Mercury (Hg) is a highly toxic metal that has detrimental effects on wildlife. We surveyed Hg concentrations in 10 species of bats collected at wind farms in the central United States and found contamination in all species. Mercury concentration in fur was highly variable both within and between species (range: 1.08-10.52 µg/g). Despite the distance between sites (up to 1200 km), only 2 of the 5 species sampled at multiple locations had fur Hg concentrations that differed between sites. Mercury concentrations observed in the present study all fell within the previously reported ranges for bats collected from the northeastern United States and Canada, although many of the bats we sampled had lower maximum Hg concentrations. Juvenile bats had lower concentrations of Hg in fur compared with adult bats, and we found no significant effect of sex on Hg concentrations in fur. For a subset of 2 species, we also measured Hg concentration in muscle tissue; concentrations were much higher in fur than in muscle, and Hg concentrations in the 2 tissue types were weakly correlated. Abundant wind farms and ongoing postconstruction fatality surveys offer an underutilized opportunity to obtain tissue samples that can be used to assess Hg contamination in bats. Environ Toxicol Chem 2018;37:160-165. © 2018 SETAC.