Cadmium Concentrations In Liver Research Articles

A comparative study of cadmium and copper in ruffed grouse ( Bonasa umbellus) in regions with and without historic mining

Mining activities can increase the bioavailability of metals in aquatic and terrestrial ecosystems. Following over 100 years of copper mining in portions of Michigan's Upper Peninsula (UP) terrestrial ecosystems retain vast quantities of waste rock with traces of cadmium and large concentrations of copper. We compared liver cadmium and copper concentrations in ruffed grouse ( Bonasa umbellus), a popular game bird from landscapes with and without historic mining. We also used chickens ( Gallus domesticus) to determine whether mine waste was a direct source of liver cadmium. Cadmium and copper levels did not differ between mining areas in Michigan and non-mining areas in Wisconsin. We found nearly significant difference between sexes in cadmium levels. Cadmium levels for all chickens were below the method detection limit of the lab (0.03 mg/kg) and copper levels did not differ in the experimental chickens. These results suggest that the historic mining in the western UP is not leading to higher cadmium or copper uptake in grouse.

Circumpolar pattern of mercury and cadmium in ringed seals

Mercury (Hg) and cadmium (Cd) concentrations in ringed seal liver and kidney were compared from 11 locations across the Arctic, from Alaska, Canada, Greenland, Svalbard to the White Sea. Adult and sub adult seals were evaluated separately to account for age accumulations of Hg and Cd. Only recently (1995–2001) collected samples were included to minimize influence of changes over time. The Hg and Cd concentrations in ringed seal liver and kidney differed significantly among the studied locations. The Hg concentrations in liver of ringed seals was highest in the western Canadian Arctic locations, while Cd in liver was highest in the eastern Canadian and West Greenland locations. In general, Hg and Cd concentrations in liver and kidney were significantly higher in adult ringed seals than in sub adults and the circumpolar patterns were most pronounced in adult ringed seals. The Hg and Cd concentrations in kidney of ringed seals in general supported the geographical pattern found in livers although the coverage was more limited. The most likely explanation for the observed circumpolar pattern appears mainly to be related to natural geological differences in mineral (Hg and Cd) among regions.

Public health evaluation of cadmium concentrations in liver and kidney of moose ( Alces alces) from four areas of Alaska

Liver and/or kidney samples were collected from 139 hunter-killed moose from four areas of Alaska during 1986. The concentration of cadmium in organ tissue was determined by direct-current plasma atomic emission spectrometry. All results are reported as μg/g wet weight. Concentrations of cadmium in liver ranged from 0.06 μg/g to 9.0 μg/g; in the kidney cortex they ranged from 0.10 μg/g to 65.7 μg/g. Cadmium levels were significantly associated with location and age. The highest geometric mean liver (2.11 μg/g) and kidney cortex (20.2 μg/g) cadmium concentrations were detected in moose harvested near Galena, Alaska. Limited dietary information from Alaska and Canada indicates that the intake of moose liver or kidney does not exceed, in most individuals, the World Health Organization recommendations for weekly cadmium consumption of 400 μg to 500 μg. Additionally, human biomonitoring data from Canada and Alaska indicate exposure to cadmium is low except for individuals who smoke cigarettes. Given the nutritional and cultural value of subsistence foods, the Alaska Division of Public Health continues to support the consumption of moose liver and kidney as part of a well-balanced diet. Human biomonitoring studies are needed in Alaska to determine actual cadmium exposure in populations with a lifelong history of moose liver and kidney consumption.

Fertility and content of cadmium in pheasant (Phasianus colchicus) following cadmium intake in drinking water

In this study, the effects of cadmium applied per os on fertility, live weight of newly hatched chicks, and cadmium concentrations in some organs of young and adult pheasants were investigated. The metal was applied at the concentration of 1.5 mg Cd 2+/L during 3 months. After the egg laying, the numbers of eggs laid, cracked, and unfertilized were determined and the live weights of newly hatched chicks were measured. The cadmium concentrations in liver, kidney, and muscle ( m. pectoralis) of young and adult pheasants were analyzed. We found that cadmium exposure of the adults did not affect the number of eggs laid but resulted in more eggs being damaged. Hatchlings were significantly heavier in the cadmium-treated group (21.36±2.28 g) compared to the control group (20.91±1.97 g) 4 weeks after the cadmium intake. Higher cadmium concentrations were observed in the muscle and kidney tissue of newly hatched pheasants after 4 weeks compared to the cadmium-exposed groups after 8 and 12 weeks. The cadmium concentrations in kidneys and liver increased significantly in adult pheasants. The metal had accumulated especially in kidneys of the adult pheasants and reached levels up to 9.64 mg/kg wet weight 3 months after the daily cadmium intake in drinking water. The concentration in liver of the adults was 3.53 mg/kg wet weight.

Distribution of Cadmium and Lead in Liver and Kidney of Some Wild Animals in Slovakia

The content of cadmium and lead, as risk factors of environment, in liver and kidneys of wild animals as brown hare (Lepus europaeus), yellow-necked mouse (Apodemus flavicollis), wood mouse (Cleithrionomys glareolus), and red deer (Cervus elaphus) were studied. Samples were analyzed by the atomic absorption spectrophotometry method (AAS). The highest levels of cadmium were found in kidneys (0.213–2.387 mg/kg) of all animal species. The concentration of cadmium in liver was 0.032–0.258 mg/kg. The analysis of lead showed that the concentration of this element was higher in kidneys of yellow-necked mouse and wood mouse (0.503–0.780 mg/kg) than in liver (0.177–0.268 mg/kg). In brown hare and red deer a higher accumulation of lead in liver (0.221–1.904 mg/kg) in comparison with kidneys (0.115–0.561 mg/kg) is reported.

Concentration of Selected Metals in Liver, Kidney, and Muscle of the Red Deer (Cervus elaphus)

Concentration of cadmium, lead, chromium, zinc, copper, and manganese in liver, kidney, and muscle of red deer was investigated. For analysis of the content of these trace elements an AAS method was used. The concentration of cadmium was significantly (p < 0.05) higher in kidney in comparison with liver and muscle. The level of lead was the highest in muscle (p < 0.05). Lower values were detected in liver and in kidney. The concentration of chromium was very similar in all studied tissues. A higher concentration of zinc was found in muscle, followed by kidney and liver. The level of copper was significanlty higher in liver (p < 0.05), and lower in kidneys and muscle. In evaluation of the concentration of manganese in red deer, the highest concentration of this element in liver was detected.

영종도와 삼목도에 도래하는 섭금류(Shorebirds)의 간과 신장에서 중금속 농도

본 연구는 우리나라 영종도와 삼목도에 도래하는 섭금류(Shorebirds)의 간과 신장에서 중금속 축적에 대한 연구이다. 아연의 농도는 영종도의 큰뒷부리도요의 간과 신장에서 각각 76.7 ㎍/wet g, 65.8 ㎍/wet g으로서 가장 높은 농도를 보였다. 망간의 경우, 간에서 가장 높은 농도는 4.68㎍/wet g을 나타낸 영종도의 청다리도요였고, 신장에서는 삼목도의 흰물떼새에서 18.61㎍/wet g으로 가장 높았다. 구리농도는 영종도 큰뒷부리도요의 간과 신장에서 각각 25.4 ㎍/wet g과 44.1 ㎍/wet g으로 가장 높았다. 납 농도가 가장 농도가 높게 나타난 종은 삼목도의 좀도요로서 간에서 17.0 ㎍/wet g, 신장에서 40.2 ㎍/wet g이었다. 그리고 납 농도는 모든 종에서 신장에서의 농도가 간에서의 농도보다 높게 나타났다. 간에서 카드뮴 농도는 0.73±0.26㎍/wet g을 나타낸 영종도의 민물도요에서 가장 높았고, 신장에서는 영종도의 흰물떼새에서 4.89±1.49 ㎍/wet g으로 가장 높았다. 카드뮴은 모든 종에서 간보다는 신장에서 농도가 높았다. 그리고 간과 신장에서의 납과 카드뮴 농도는 붉은어깨도요를 제외하고는 영종도에서의 농도가 삼목도보다 높았다. This study was about heavy metal accumulation in liver and kidney of Shorebirds migrating to yeongjong and Sammok Island. Zinc concentration was highest in liver(76.7 ㎍/wet g) and kidney (65.7 ㎍/wet g) of Limosa lapponica to Yeongjong Island. In case of manganese, the highest accumulation in liver was Tringa nebularia to Yeongjong Island, and in kidney was Charadrius alexandrinus, to Sammok Island, respectively 4.68㎍/wet g, 18.6㎍/wet g. Copper concentration was th highest that in liver(25.4㎍/wet g) was Limosa lapponica to Yeongjong Island, in kidney(11.7 ㎍/wet g) was Tringa cinereus to Sammok Island. Calidris ruficollis to Sammok Island was the highest accumulated lead and concentration was 17.0㎍/wet g in liver, 40.2 ㎍/wet g in kidney. Lead concentration was more in kidney than in liver. Cadmium concentration in liver was the highest accumulated Calidris alpina(0.73±0.26 ㎍/wet g) to Yeongjong Island, in kidney was the highest accumulated Charadrius alexandrinus(4.89±1.49 ㎍/wet g) to Yeongjong Island. Cadmium concentration was higher in kidney than in liver to all species. Therefore, lead and cadmium concentration was more to Yeongjong than to Sammok Island in liver and kidney except Calidris tenuirostris.

Metal concentrations in selected organs and tissues of five Red-knobbed Coot (&lt;i&gt;Fulica cristata&lt;/i&gt;) populations

The Red-knobbed Coot Fulica cristata is an abundant aquatic bird in South Africa and was anticipated to have indicator abilities for metal pollution. This hypothesis was tested on 83 coot samples collected from five selected aquatic ecosystem areas supporting substantial coot populations, of which various abiotic and biotic components are known to contain varying levels of a number of metals. The aim of this study was achieved by determining the variations in Cd, Cu, Ni and Pb concentrations in liver, kidney, bone and blood samples, with the use of standard flame atomic absorption spectrophotometry techniques. Coots from the Germiston Lake sampling site showed the highest concentrations of cadmium in liver (2.2 µg/g d.w.) and kidney (5.4 µg/g d.w.). The absence of metalprocessing industries in the catchments of the Florida Lake and the Steynsrus farm dams reflects the low liver and kidney concentrations of Cd, Ni and Cu, respectively. The blood of the Natalspruit wetland coots contained the highest dry weight concentrations of Ni (11.4 µg/g), Cd (1.8 µg/g) and Cu (14.4 µg/g). The statistical evaluation points towards small-scale geographical differences, especially in the concentrations of Cu, Ni and Pb and in the liver, kidney and blood. However, in terms of actual metal concentrations recorded, no significant differences existed between coots of the reference site (Steynsrus farm dams) and those from the other four localities. It is concluded that the impact of metal-containing diets on the tissue concentrations of these metals in birds plays a far more significant role compared to the migratory habits or short-range movements of the coots.

Low iron diet and parenteral cadmium exposure in pregnant rats: the effects on trace elements and fetal viability.

The effects of latent iron deficiency combined with parenteral subchronic or acute cadmium exposure during pregnancy on maternal and fetal tissue distribution of cadmium, iron and zinc, and on fetal viability were evaluated. Timed-pregnant Sprague-Dawley rats were fed on semisynthetic test diets with either high iron (240 mg kg) or low iron (10 mg kg), and concomitantly exposed to 0, 3 or 5 mg cadmium (as anhydrous CdCl2) per kilogram body weight. Animals were exposed to cadmium from gestation day 1 through 19 by subcutaneously implanted mini pumps (Subchronic exposure) or on gestation day 15 by a single subcutaneous injection (Acute exposure). All rats were killed on gestation day 19. Blood samples, selected organs and fetuses were removed and prepared for element analyses by atomic absorption spectrometry. Low iron diet caused decreases in maternal body weight, maternal and fetal liver weights, placental weights and tissue iron concentrations. By cadmium exposure, both subchronic and acute, tissue cadmium concentrations were increased and the increase was dose-related, maternal liver and kidney zinc concentrations were increased, and fetal zinc concentration was decreased. Cadmium concentration in maternal liver was additionally increased by low iron diet. Acute cadmium exposure caused lower maternal body and organ weights, high fetal mortality, and decreased fetal weights of survivors. In conclusion, parenteral cadmium exposure during pregnancy causes perturbations in essential elements in maternal and fetal compartments. Acute cadmium exposure in the last trimester of gestation poses a risk for fetal viability especially when combined with low iron in maternal diet.

Postnatal development of hepatic oxidative, hydrolytic and conjugative drug-metabolizing enzymes in female horses

Little is known about the effects of aging on the hepatic drug metabolizing capacity of horses despite the relatively long lifespan characterizing this species. A wide array of cytochrome P450 (CYP)-dependent monooxygenases, carboxylesterases and transferases were assayed in liver microsomes from 50 female horses in an age range between less than 1 year to over 12 years. Rather unexpectedly, both the CYP content and the activity of NADPH cytochrome c reductase rose as a function of age. Accordingly, a general increasing trend was recorded in the rate of the in vitro metabolism of the substrates reported to be related to CYP2B-, CYP2E- or CYP3A, although, as detected by Western immunoblotting, only the levels of proteins recognized by anti-rat CYP3A- and CYP2B antibodies appeared to increase consistently. Also the carboxylesterases and uridindiphosphoglucuronyl-transferase (UGT) activity toward 1-naphthol displayed a similar trend, glutathione S-transferase accepting 3,4-dichloronitrobenzene as a substrate being the only enzyme activity showing an age-related decline. A positive correlation was also found between liver cadmium content and CYP amount as well as the activities of most monooxygenases (except for those related to CYP1A), carboxylesterases, and UGT. While confirming that a number of enzyme activities are less expressed in foals, our results contradict the general view that the drug metabolizing capacity drops in elder individuals. Although several other factors can influence the kinetics of foreign compounds in aged animals, data from this study may provide insight in understanding possible age-related differences in drug efficacy and the response to toxic substances in horses.

Toxic and essential trace metals in muscle, liver and kidney of bovines from a polluted area of Morocco

Toxic and essential trace metals were measured in muscle, bone, liver and kidney of bovine grazing on the municipal wastewater spreading field of Marrakech City (Morocco). Bovines were found to be seriously contaminated by toxic metals, especially cadmium, and levels were higher in liver and kidney, specific target organs for metal bioaccumulation. The high cadmium content seemed to contribute to a reduction in zinc and copper levels. The arithmetic mean concentrations of zinc, copper and cadmium in liver and kidney, were respectively: 126, 112 and 5.1 μg/g in liver; 89, 33 and 10.3 μg/g in kidney.

Accumulation of Lead, Cadmium, and Mercury in Liver and Kidney of the Brown Hare (Lepus europaeus) in Relation to the Season, Age, and Sex in the West Slovakian Lowland

Concentrations of lead, cadmium, and mercury in liver and kidneys of brown hares in relation to season, age, and sex were investigated. Over a period of one year 74 hares, 36 males and 38 females were analyzed. The concentrations of lead and cadmium were analyzed by AAS and mercury was determined by mercury vapor technique. The median concentration of lead in liver as well as in kidney in relation to the season is the highest in winter period in comparison with spring, summer, and summer period (p<0.001). The highest concentration of cadmium was found in winter, but the differences were not significant. In mercury, we report significantly higher (p<0.001) median concentrations in liver (0.023 mg kg−1) as well as in kidney (0.068 mg kg−1) in winter period in comparison with all other observed periods. In relation to age the concentrations in lead and mercury in liver and kidney were very similar, without significant differences. In cadmium we report significantly higher concentrations in the liver as well as kidney in adult animals (0.154 and 1.521 mg kg−1) in comparison with juvenile animals (0.048 and 0.582 mg kg−1, respectively). In comparison of the female and male brown hares we found significantly higher (p<0.05) median concentration of lead in the liver of males (0.216 mg kg−1) than in females (0.127 mg kg−1) and the level of cadmium is significantly higher (p<0.001) in females (1.464 mg kg−1) than in male brown hares (1.384 mg kg−1).

Effect of cadmium on bromosulfophthalein kinetics in the isolated perfused rat liver system.

Bromosulfophthalein (BSP) is a relatively nontoxic organic anion used as an in vivo indicator of liver performance. Elimination of BSP via the biliary system following iv injection requires dissociation from albumin in plasma, translocation across the sinusoidal membrane, conjugation with glutathione within the hepatocyte, translocation across the bile canalicular membrane, and excretion in bile. The effects of cadmium (Cd), anin vivo hepatotoxicant in rats, on BSP kinetics in the isolated perfused rat liver (IPRL) were studied to investigate the interaction between liver toxicity and BSP kinetics. Livers were isolated from male Fisher 344 rats. After a 30-min period for acclimation to the IPRL system, livers were dosed with Cd (as cadmium acetate), in the presence of 0.25% bovine serum albumin, to give initial concentrations of 10 and 100 microM. Sixty min after Cd dosing, the IPRL system was dosed with BSP to give an initial concentration of 150 microM and the elimination kinetics of BSP from the perfusion medium were monitored. Cadmium concentrations in livers at the end of the experiments were 60 +/- 4 and 680 +/- 210 micro mol/kg for the 10 and 100 microM doses, respectively. Exposure to 10 microM Cd for 60 min resulted in a reduction in bile flow, no significant effect on lactate dehydrogenase (LDH) leakage, and slight effects on BSP clearance. Similar studies following exposure to 100 microM Cd showed a dramatic decrease in bile flow with complete cholestasis 60 min after Cd addition. LDH leakage into perfusion medium at the end of the experiment was less than 10%, indicating that Cd affected bile production well before the liver showed significant signs of necrosis. Clearance of BSP from the perfusion medium was dramatically reduced. Taken together, the data indicate that Cd has a significant effect on the kinetics of BSP in the IPRL and the dominant effects were mediated through the cholestatic effect of Cd.

Kidney, liver and bone cadmium content in the western sandpiper in relation to migration.

Cadmium content was measured in kidney, liver and tarsus bones of western sandpipers (Calidris mauri) at a temperate migratory stopover site (Fraser Delta, British Columbia, Canada) and a wintering site (Playa el Agallito, Chitre, Panama) over a two year period. Cadmium content in liver and kidney was age and sex dependent. Adult females generally had lower kidney and liver cadmium than adult males (P < 0.05), but a sex difference was not detected in juveniles. Cadmium increased with age in kidney, liver and to a lesser extent in bone (P < 0.001) with average "steady-state" kidney and liver content being reached within the sandpipers first year. In general, tissue cadmium residues in adult males and females were independent of sampling location although for bone, site-specific differences did occur (P < 0.001). Bone cadmium was lower in females sampled from their wintering grounds as compared to temperate stopover sites suggesting that bone cadmium may be mobilized during periods of feather molt. Comparison of cadmium residues among sandpipers of increasing age suggest that exposure is occurring along the Pacific Coast, at stopover sites as the birds migrate north to Alaska and south to Panama. This study points to the importance of considering the ecology of the species (e.g., in this case migratory behavior) in interpreting trace metal residues.

Cadmium, copper and zinc in tissues of deceased copper smelter workers

Workers at a copper and lead smelter in northern Sweden have a multifactorial exposure to a number of heavy metals. The concentrations of cadmium, copper and zinc in liver, lung, kidney and brain tissues have been determined by atomic absorption spectrometry in 32 deceased long-term exposed male lead smelter workers, and compared with those of 10 male controls. Furthermore, copper and zinc levels in hair and nails were determined by energy-dispersive X-ray fluorescence. The highest cadmium concentrations among both workers and controls were observed in kidney, followed in order by liver, lung and brain. The levels in kidney, liver and lung were all significantly higher in the workers than in the controls (p < 0.03). Among the workers relatively strong positive correlations (p < 0.03) were observed between cadmium concentrations in liver and lung, liver and kidney, liver and brain, and lung and brain. In the exposed workers a positive correlation was observed between cadmium and zinc concentrations in the kidney (r s = 0.38; p = 0.034). This is probably mainly due to the protein metallothionein, which is stored in the kidney, binding equimolar amounts of these two metals. The highest concentrations of copper were found in hair and nails among both workers and controls, followed in order by liver, brain, kidney and lung. The tissue concentrations of copper in brain, lung and kidney were all significantly higher among the smelter workers than in the controls (p ≤ 0.036). Copper levels in lung and age at time of death were positively correlated among the exposed workers (r s = 0.39; p = 0.029). In the same group, positive correlations between copper and zinc concentrations in kidney (r s = 0.45; p = 0.009) and nails (r s = 0.68; p < 0.001) were also observed, reflecting possible biological interactions between these two metals. Among both workers and controls, the highest zinc concentrations were found in hair, followed in order by nails, liver, kidney, brain and lung. Significantly higher tissue concentrations among the workers as compared with the reference group were noted in kidney, liver and brain (p ≤ 0.033). Neither copper nor zinc concentrations in hair and nails seemed to provide a useful measure of the trace element status of the smelter workers.

Concentrations of Cadmium, Zinc, Copper, Iron, and Metallothionein in Liver and Kidney of Nonhuman Primates

To evaluate the species specificity of Cd accumulation and the relationship of Cd with other essential metals and metallothionein (MT), the concentrations of Cd, Zn, Cu, and Fe in the liver and kidney and the MT concentrations in the soluble fractions of the liver and kidney were determined in Cd-uncontaminated nonhuman primates (11 species, 26 individuals) kept in a zoo and two wild-caught Japanese macaques. The compositions of metal-binding proteins in the soluble fractions were also investigated by high-performance liquid chromatography (HPLC). The hepatic Cd concentration was 0.03-14.0 microg/g and the renal Cd concentration was 0.35-99.0 microg/g, both varying greatly and being higher in nonhuman primates, which were more closely related to man. The hepatic Zn concentration was 24.0-176 microg/g and the renal Zn concentration was 13.5-138 microg/g, showing 7- to 10-fold differences, and a correlation (r=0.558, p<0.01) was found between renal Zn and renal Cd concentrations. It was proved that in the liver, MT is more closely correlated with Zn (r=0.795, p<0.001) than with Cd (r=0.492, p<0.01) and that in the kidney MT is correlated with both Cd (r=0.784, p<0.001) and Zn (r=0.742, p<0.001). HPLC analysis of metals bound to MT-like protein in chimpanzees, de Brazza's monkeys, and Bolivian squirrel monkeys showed that more than 90% of Cd in both the liver and kidney, approx 40% of Zn in liver and 28-69% of Zn in kidney were bound to MT-like protein. The higher percentage Zn was bound to high-molecular protein.

Dexamethasone Prevents Acute Cadmium-Induced Hepatic Injury but Exacerbates Kidney Dysfunction in Rabbits

Cadmium is a potent hepatotoxicant for which neither effective preventive methods nor the mechanism of toxicity has been established. We investigated the preventive effect of dexamethasone against cadmium toxicity on cadmium-induced liver injury in rabbits. Pretreatment with dexamethasone at 1 mg/kg increased the rate of survival in rabbits administered 2.5 mg/kg iv cadmium. Cadmium induced acute severe liver injury characterized by hepatocellular necrosis, infiltration by inflammatory cells, and increases of plasma GOT, GPT, LDH, and LDH5. Dexamethasone mitigated the acute hepatotoxic effect of cadmium, but exacerbated cadmium-induced kidney dysfunction, with destruction of renal tubular cells and increases in excretion of protein, glucose, and amino acids into urine. The cadmium concentration in liver and kidney of rabbits administered cadmium was not changed by dexamethasone pretreatment. Although metallothionein mRNA expression induced by cadmium was not affected by dexamethasone in liver or kidney, cadmium-induced metallothionein protein production was augmented at the early phase in liver and decreased at the later phase in kidney. Neutrophilia observed after cadmium administration was enhanced initially by dexamethasone pretreatment. These results indicate that dexamethasone pretreatment potently prevented cadmium-induced liver injury, but exacerbated renal tubular dysfunction.

Concentrations of cadmium, mercury and selenium in blood, liver and kidney of common eider ducks from the Canadian arctic.

We determined concentrations of selected trace elements in livers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadian arctic during 1997 and 1998. Concentrations of total mercury and organic mercury were generally low in the livers of these birds (less than 6 and 4 microg g(-1) dry wt, respectively). Selenium ranged between 11-47 microg g(-1) in livers. Renal cadmium concentrations were among the highest ever published for this species (range: 47-281 microg g(-1)). The regressions of log-transformed concentrations of these trace elements in blood samples on those in liver or kidney were significant (all P-values < 0.05) and positive. However, except for organic mercury (R2 = 0.83), the co-efficients of determination were low to moderate (range of R2: 0.26-0.52), suggesting poor to moderate predictive capability. Furthermore, the relationships between total mercury in blood and liver changed between 1997 and 1998, suggesting that it would not be possible to predict consistently, concentrations of mercury in blood from those in liver based on samples taken in one year. Blood samples can be used to determine concentrations of these trace elements in common eiders (and probably other sea duck species as well). The use of blood samples is especially warranted when it is undesirable to kill the animal such as when working with rare or endangered sea duck species or when the objective is to relate trace element exposure to annual survival rates. However, the predictive equations developed here should not be used to predict expected concentrations in one type of tissue from those in the other.

Cadmium in organs and tissues of horses slaughtered in Italy

The cadmium content of muscle, liver, kidney and blood samples from 62 horses slaughtered in Italy was investigated. Cadmium was determined by graphite furnace atomic absorption spectrometry (GFAAS) after wet digestion of the samples. The mean and median contents of all samples were (on a fresh weight basis) 75 and 41 μgkg-1 for muscle, 2.46 and 2.10 mgkg-1 for liver, 20.0 and 13.5 mgkg-1 for kidney. The cadmium level in blood samples was always below 6 μgl-1. The cadmium concentrations in muscle, liver and kidney were found to be related to the life span of the specimens and increased with age. Females exhibited higher levels than males, but this difference was significant only in the case of muscle tissue. The geographical origin was recognized as the main factor influencing the cadmium content of the equine specimens analysed. The differences between horses coming from the three main breeding countries considered in this study (Poland, Lithuania, Hungary) were marked and statistically significant. The average intake of cadmium from equine meat was estimated for the general population and for population groups resident in areas with high consumption of this food item. While the cadmium intake from equine meat for the average consumer accounts for about 1% of the total cadmium intake estimated for Italy, in the latter case the enhanced consumption of equine muscle is often accompanied with the consumption of substantial quantities of equine liver and this may lead to high cadmium intakes.

A model to predict kidney and liver cadmium concentrations in grazing animals

Cadmium (Cd) accumulation in the kidneys and liver of older grazing animals is a major concern in New Zealand and Australian agriculture. Use of phosphate fertilisers containing high Cd concentration is the main cause of this accumulation. A simple mathematical model running in a user‐friendly computer package was developed to predict annual accumulation of Cd in kidneys and liver of animals grazing pastures of known herbage Cd concentration and phosphate fertiliser history. Results from the model showed that kidney and liver Cd concentration of sheep were most sensitive to fertiliser Cd concentration, moderately sensitive to pasture ingestion rate, and least sensitive to soil ingestion rate. The model was validated using kidney Cd data from a farmlet‐scale sheep‐grazing trial. Kidney Cd concentrations predicted by the model were strongly correlated with measured mean kidney Cd concentrations. The relationship between the measured and predicted Cd concentrations is not statistically different from the 1:1 relationship indicating that the model can explain the variation in the measured mean kidney Cd concentration.