Distribution of heavy metals in muscle, liver and kidney of northern fur seal (Callorhinus ursinus) caught off Sanriku, Japan and from the Pribilof Islands, Alaska

The concentrations of iron, manganese, zinc, copper, cadmium, and mercury were determined in muscle, liver and kidney of 67 northern fur seals (Callorhinus ursinus) collected off Sanriku, Japan, and from the Pribilof Islands, Alaska. Almost all the elements except cadmium were highest in liver. Cadmium levels in kidney were higher than those in liver and muscle for all animals analyzed. Concentrations of mercury increased significantly with age in muscle, liver and kidney, as did iron levels in muscle and liver and cadmium levels in muscle, while manganese concentrations decreased with age in muscle and kidney. The kidney also showed decreased copper concentration with age. Cadmium concentrations of the northern fur seals in this study were higher than the other otariids, reflecting a predominantly squid diet. Concentrations of manganese and mercury were found to be higher in the fur seals caught off Sanriku than in animals from the Pribilof Islands, while those of zinc and cadmium were found to be lower. Variable concentrations of cadmium might have been attributed to those in seawaters. Discriminant analysis of heavy metal concentrations was used to identify habitat. Sixty-three of 67 animals (94%) were correctly classified using this technique. Heavy-metal concentrations in tissues may provide a useful method to elucidate the primary feeding grounds of fur seals.     

Heavy metal contamination in bats in Britain

Toxic metals are bioaccumulated by insectivorous mammals but few studies (none from Britain) have quantified residues in bats. We measured renal mercury (Hg), lead (Pb) and cadmium (Cd) concentrations in bats from south-west England to determine how they varied with species, sex, age, and over time, and if they were likely to cause adverse effects. Residues were generally highest in whiskered bats (Myotis mystacinus). Compared with other species, pipistrelle (Pipistrellus spp) and Natterer's bats (Myotis nattereri) had significantly lower kidney Hg and Pb concentrations, respectively. Renal Hg increased over time in pipistrelles but the contributory sources are unknown. Kidney Pb did not decrease over time despite concurrent declines in atmospheric Pb. Overall, median renal metal concentrations were similar to those in bats from mainland Europe and 6- to 10-fold below those associated with clinical effect, although 5% of pipistrelles had kidney Pb residues diagnostic of acute lead poisoning.     

Tissue heavy metal concentrations of stranded California sea lions (Zalophus californianus) in Southern California

Concentrations of nine heavy metals (As, Cd, Cu, Fe, Hg, Pb, Mn, Mo and Zn) were determined in the hepatic and renal tissues of 80 stranded California sea lions (Zalophus californianus). Significant age-dependant increases were observed in liver and kidney concentrations of cadmium and mercury, and renal zinc concentrations. Hepatic iron concentrations were significantly higher in females than males. Animals with suspected domoic acid associated pathological findings had significantly higher concentrations of liver and kidney cadmium; and significantly higher liver mercury concentrations when compared to animals classified with infectious disease or traumatic mortality. Significantly higher hepatic burdens of molybdenum and zinc were found in animals that died from infectious diseases. This is the largest study of tissue heavy metal concentrations in California sea lions to date. These data demonstrate how passive monitoring of stranded animals can provide insight into environmental impacts on marine mammals.     

Heavy metals in two populations of North Atlantic fin whales (Balaenoptera physalus)

Concentrations of cadmium, copper and zinc have been analyzed in muscle, liver and kidney tissues of fin whales (Balaenoptera physalus) from two locations in the North Atlantic, Iceland and Spain. The concentrations of zinc in the muscle and that of cadmium in the liver and the kidney were significantly higher in fin whales from Iceland. Other differences between whales from the two areas concern the dynamics of cadmium in the organism. These findings support the hypothesis that fin whales from the two sites belong to different stocks and that cadmium in the organism can be used as a complementary tool in studies of population identity.     

Cadmium in food production systems: a health risk for sensitive population groups

This paper gives an overview of the cadmium (Cd) situation in agricultural systems and human exposure in Sweden. Cadmium levels in agricultural soils (the plow layer) increase by 0.03% to 0.05% per year. Feed can give substantial contributions of Cd to local agricultural systems. Effects on human kidney function are indicated by some measurements already at today's exposure levels. If food products reach the maximum permissible levels given by the European Union, 10% to 25% of the Swedish population will be exposed to Cd levels above the provisional tolerable weekly intake (PTWI 7 microg Cd kg(-1) body weight). Sensitive groups in the population are individuals with low iron status (mainly women) and kidney disorders. Recent studies indicate that Cd plays a role in osteoporosis and that further research is needed to clarify if Cd is neurotoxic in early developmental stages. Firm actions have to be taken in order to stop a further increase of Cd in agricultural soils. Suggestions for prevention and measures are given in this paper.     

Cellular alterations in different organs of European sea bass Dicentrarchus labrax (L.) exposed to cadmium

Specimens of farmed European sea bass (Dicentrarchus labrax L., 1758) were exposed to different cadmium (Cd) concentrations (4.47, 5.63, 7.08 and 8.91 mg l(-1)) for 24 and 48 h. The effects of Cd on numbers of some cell types and structures (i.e., chloride cells, CCs; macrophage aggregates, MAs; rodlet cells, RCs) and on structure and ultrastructure of the main organs (gill, liver, intestine, kidney) were studied with routine process for light and transmission electron microscopy. Following cadmium exposure, the numbers of branchial CCs as well as intestinal and renal RCs increased significantly within 24h. Increase in metal concentration did not affect the magnitude of the numerical increment of the aforementioned cells. Moreover, in treated fish (24 and 48 h) the numbers of MAs in both head kidney and spleen were significantly higher than in control conspecifics, whilst the global area of MAs was less influenced by the acute treatment. In exposed sea bass, all the examined organs exhibited cellular modifications which appeared time- and dose-dependent. The gills showed telangectasia, lamellar fusion, oedema, epithelial lifting and leukocyte infiltration. In the liver, kidney and intestine acute cell swelling and vacuolization were common. Ultrastructurally the alterations observed frequently in hepatocytes, tubular epithelial cells and enterocytes included presence of numerous myelinoid bodies, damaged mitochondria, dilatation of endoplasmic reticulum, high number of lysosomes and autophagolysosomes. In intestinal and kidney tubular epithelia of treated fish, rodlet cells displayed some anomalies like dilatation of nuclear envelope, cytoplasmic vacuolization, presence of myelinoid bodies, rodlets degeneration and extensive discharge activity.     

Willow ptarmigan (Lagopus lagopus) as a biomonitor of environmental metal levels in Norway

The purpose of this study was to examine the potential of a native wild bird, Lagopus lagopus, as a monitor of environmental metal levels, in particular with respect to the influence of atmospheric deposition of metals from long-range transport. Specimens of willow ptarmigan were collected from ten different locations in Norway. The concentrations of cadmium, zinc and copper were determined in kidneys of birds from all sites. Mean cadmium levels in adult ptarmigan kidney ranged from 6.6 to 48.5 microg g(-1) (wet weight), with individual concentrations up to 71.0 microg g(-1). These are among the highest cadmium levels reported in wild birds. The kidneys of adult birds contained 3-10 times higher cadmium levels than kidneys from juvenile birds in the same collection area, and most of the high cadmium levels probably reflect natural exposure, rather than atmospheric pollution. Concentrations of elements in kidney tissues were highly correlated with each other.     

Effect of cadmium on ATPase activities in rats fed on iron-deficient and sufficient diets

Male Sprague-Dawley rats were fed on different levels of cadmium mixed with purified diets containing iron or no iron for 8 weeks. The body weight gain, tissue weights, hemoglobin, hematocrit, liver and brain ATPase were measured at 2, 4 and 8 weeks after feeding. The hemoglobin and hematocrit values were the same in all rats fed on cadmium. The rats fed on iron-deficient diets mixed with cadmium showed a significant decrease in body weight gain. However, the rats receiving only the 100 ppm of cadmium in iron-sufficient diet showed a significant decrease in body weight gain. There were no significant changes in the weights of thymus, spleen, kidney, heart, brain and testes. However, the liver weights were decreased in the highest treatment of cadmium but the liver weight/body ratios were uneffected. Na+-K+ activated ATPase activity in brains of rats fed on cadmium were significantly decreased at 2, 4 and 8 weeks of treatment. The decrease was more pronounced in rats fed on iron-deficient diets. Oligomycin-sensitive (Mitochondrial) Mg2+ ATPase activity was also significantly decreased in liver and brain tissues of rats fed on cadmium. Oligomycin-insensitive Mg2+ ATPase activity, however, was not altered in any tissues tested. It appears that cadmium may be interfering with energy (ATP) production and utilization processes in rat brain and liver tissues.     

The association between environmental cadmium exposure,blood pressure,and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were???0.795 and???1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

     

Metal concentrations in seabirds of the New Zealand region

Concentrations of the heavy metals cadmium, copper, lead, zinc, mercury and, in some individuals, methyl mercury were determined in a range of tissues of 64 tropical, subtropical, subantarctic and antarctic seabird taxa mostly from the New Zealand region. Although apparently natural, levels of cadmium and mercury in some species greatly exceed those known to have toxic effects in some terrestrial birds. Copper and zinc levels exhibited less inter-species variation than the non-essential metals cadmium and mercury. Cadmium concentrations were highest in kidney tissues but uniformly low in feathers. Total mercury concentrations showed most inter-species variation. Mean methyl mercury levels in liver tissues of several large procellariiforms represented less than 5% of the corresponding mean total mercury level. Lead concentrations were generally low or below the limits of detection, but elevated levels were measured in some coastal or scavenging species. In a significant number of species, mean concentrations of liver cadmium and mercury and kidney cadmium were greater in adults than in young birds. The reverse was true for copper. Mean zinc levels in liver did not differ between adults and young. High levels of cadmium in some species seem likely to be due to diet, whereas high levels of mercury probably reflect more closely the moult intervals which constrain the ability of birds to eliminate methyl mercury.     

The current status of osteoporosis after 15 years of reduced cadmium exposure among residents living in cadmium-contaminated areas in northwestern Thailand

The purposes of this study were to determine the prevalence of osteoporosis after 15 years of reduced cadmium exposure and to determine the association between urinary cadmium (U-Cd) and osteoporosis. The study was conducted with 937 participants (109 males, 828 females) living in a cadmium-contaminated area in northwestern Thailand. All participants were required to respond to a questionnaire. Bone mineral density (BMD) was investigated by measurements taken at the calcaneus by dual-energy X-ray absorptiometry. U-Cd, which reflects the amount of cadmium contained in the body, was measured by atomic absorption spectrophotometry (AAS). The geometric mean of U-Cd was significantly higher in males than in females (p < 0.001). The mean level of BMD for females was found to be statistically significantly lower than that for males (p < 0.001). Increasing U-Cd levels were correlated with decreasing levels of BMD. The association between U-Cd and osteoporosis appeared to exist only at concentrations of U-Cd ≥ 10 μg/g creatinine (OR = 2.7, 95% CI = 1.2–5.9). It can be concluded that despite discontinued or reduced cadmium exposure for more than 10 years, the effect of cadmium toxicity on bone, which is stronger in women, continues, as cadmium, once absorbed, will accumulate in the human body for a long time due to its extremely long half-life.

     

Accumulation of orally administered cadmium by the eel (Anguilla anguilla)

Eels were fed on gammarids (Amphipoda: Crustacea) containing high levels of cadmium for 30 days, then the cadmium distribution in the various organs of the fish was investigated. A retention value was calculated for liver + kidney and for whole-body.     

Cadmium background content in meat,liver and kidney from cattle and its consequences to cadmium tolerance levels (x)

The natural background of cadmium content in meat, liver and kidney from 287 cattle from a non polluted area in the subalpine region of Bavaria has been analyzed during the period from 1972 to 1975. The cadmium content in meat was always below the detection limit of 0.005, in liver between < 0.005 to 1.65 (median 0.050) and in kidney 0.008 to 1.95 (median 0.229) ppm Cadmium in fresh weight. The cadmium contents are discussed and compared with preliminary suggestions for cadmium tolerance levels and their consequence for food inspection.     

Concentrations of heavy metals in Sotalia fluviatilis (Cetacea: Delphinidae) off the coast of Ceará, northeast Brazil

Lead (Pb), cadmium (Cd) and mercury (Hg) concentrations on liver and kidney of Sotalia fluviatilis (Cetacea: Delphinidae) stranded in the coast of Ceará, Brazil, were studied from 1996 to 1999. Pb levels were usually lower than the detection limit (0.1 microg/g). Concentrations of Cd were significantly higher in kidney than liver, averaging 0.8 microg/g. Mercury accumulation took place mainly in liver with an average concentration of 4.6 microg/g. Both metals were significantly higher in larger mature individuals, but differences between sexes were not significant. The detection of Cd, Hg and Pb in tissue samples of S. fluviatilis off the coast of Ceará indicated that heavy metals are locally available in the water, and bioaccumulation may be occurring through the food web. Contamination levels were not considered critical, but could be related to Ceará's growing industrial development. The associated risks of pollution outfalls may pose a threat to marine organisms in a near future, especially for top predators such as S. fluviatilis.     

Levels and interactions of heavy metals in sea birds from Svalbard and the Antarctic

Samples of liver and kidney from 92 seabirds of ten species collected on Spitsbergen and in the Antarctic, were analysed for their content of copper, zinc, cadmium, lead, mercury and selenium. Significantly higher levels of copper and zinc were observed in birds from Spitsbergen than in those from the Antarctic, while the opposite was true for selenium. The highest cadmium levels were found in fulmar Fulmarus glacialis and macaroni penguin Eudyptes chrysolophus. A possibility of kidney damage due to cadmium exists. The highest mercury levels were recorded in brown skua Catharacta lonnbergi collected at Bouvet?ya. Lead was not detected in any of the birds. Significant correlations were observed between levels of several of the metals studied, especially between cadminum and zinc and between mercury and selenium. However, for all birds, the highest correlation coefficients were observed when the molar concentrations of cadmium plus mercury, and selenium plus zinc, were used in the calculations. Thus several protective mechanisms may operate to diminish effects of heavy metal contaminants.     

Sex-specific differences in early renal impairment associated with arsenic,lead, and cadmium exposure among young adults in Taiwan

Exposure to a single metal has been reported to damage renal function in humans. However, information regarding the association between multiple-metal exposure and markers for early renal impairment in different sexes among the young adult Taiwanese population is scarce. We assessed the association between exposure to arsenic (As), cadmium (Cd), and lead (Pb), and early renal impairment markers using urinary microalbumin (MA), β2-microglobulin (β2MG), and N-acetyl-beta-D-glucosaminidase (NAG) by analyzing 157 young adults aged 20?29 years, in Taiwan. Inductively coupled plasma mass spectrometry was used to determine urinary As, Cd, and Pb levels. Regression models were applied to different sex groups. The results showed that after adjusting for potential confounding factors and each metal, urinary Cd levels were significantly positively associated with urinary MA (β?=?0.523, 95% CI: 0.147–0.899) and β2MG (β?=?1.502, 95% CI: 0.635–2.370) in males. However, the urinary Cd level was significantly positively associated with only urinary NAG (β?=?0.161, 95% CI: 0.027–0.296) in females. This study thus indicates that the effect of exposure to metals (especially Cd) on early renal impairment among young adults in Taiwan is sex-specific. Our study results could contribute toward developing early intervention programs for decreasing the incidence of renal dysfunction. Further studies are warranted to confirm our findings and clarify the potential mechanisms involved.

     

Cadmium and lead in tissues of Mallards (Anas platyrhynchos) and Wood Ducks (Aix sponsa) using the Illinois River (USA)

Cadmium and lead concentrations were determined in the tissues of Mallards and Wood Ducks collected from two waterfowl management areas along the Illinois River, USA, during the autumn and late winter of 1997-1998. Lead concentrations in livers of Mallards were lower than previously reported, and, along with those in a small sample of Wood Duck livers, were within background levels (<2.0 microg/g wet weight). Mean concentrations of cadmium in the kidneys of Wood Ducks utilizing the Illinois River were four times greater than in after-hatch-year Mallards, and 14 times greater than in hatch-year Mallards. Concentrations of cadmium in the kidneys of Wood Ducks were comparable with those of specimens dosed with cadmium or inhabiting contaminated areas in previous studies. Wood Ducks utilizing wetlands associated with the Illinois River, and presumably other portions of the lower Great Lakes region, may be chronically exposed to cadmium.     

Influence of low-level cadmium and reduced calcium intake on tissue Cd concentrations and behaviour of American black ducks

Populations of American black ducks have declined and it has been hypothesized that wetland acidification, which can alter food quality by increasing availability of cadmium and decreasing that of calcium, may have contributed. We tested whether low-level cadmium and reduced calcium intake affect tissue cadmium concentrations and behaviour of captive black ducks. Adults received diets that mimicked cadmium and calcium concentrations in invertebrate prey from acid and from circumneutral wetlands for three spring and summer months in 1991 and 1992. Behaviours were monitored both when birds were fed experimental diets and control (commercial) diets. Cadmium in kidneys and liver differed significantly among groups and low calcium facilitated cadmium uptake. After two breeding seasons, levels of accumulated Cd were not lethal. However, birds that received Cd were significantly more active than control birds. Increased activity may have implications for survival of birds in the wild.     

Age-dependent accumulation of heavy metals in a pod of killer whales (Orcinus orca) stranded in the northern area of Japan

Mercury (Hg), cadmium (Cd), iron (Fe) manganese (Mn), zinc (Zn) and copper (Cu) concentrations in the liver, kidney and muscle of nine killer whales (including three calves) that stranded together in the northern area of Japan were determined. The Hg and Cd concentrations were found at trace levels in the calf organs, and increased with age. The Fe concentration in the muscle was significantly lower in the calves than in the mature whales and also increased with age. In contrast, Mn and Cu concentrations in the muscle were significantly higher in the calves than in the mature whales, and changes in the Zn concentration relative to age were unclear. These results suggest minimal mother-to-calf transfer of the toxic metals Hg and Cd and accumulation of these metals in the organs with age, while the essential metals Mn and Cu were found at higher concentrations in the muscle of calves than in mature whales.     

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on serum insulin and glucose levels in the rabbit

Serum insulin and glucose were measured in young male rabbits after a single intraperitoneal dose of 1 or 50 micrograms/kg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Serum insulin levels in the high dosed rabbits were significantly decreased between 15 min and 8 h post treatment, equivalent after 24 h, significantly elevated 48 h post treatment, and they were not different at 10 days post-treatment when compared to weight matched and pair-fed controls. At the low dose, rabbits showed no differences in serum insulin from controls. In the high dose group, serum glucose levels were generally not different between treated and control animals, though there was a transient hyperglycemia 1 h after treatment, and both treated groups became hypoglycemic after ten days. The results indicate that TCDD altered serum insulin levels which were not coupled to changes in serum glucose.