Ppm Cadmium Research Articles

Effect of acute exposure to cadmium on zinc, copper and lead contents of hard and soft tissues of rats

Eleven groups of Wistar rats were given 5 ppm cadmium acetate in the drinking water at different and interrupted periods of their life (in utero, during sucking etc.), simulating acute exposure. The Zn, Cu and Pb levels of indicators (teeth and hair) and target organs (soft tissues and bone) were recorded by atomic absorption spectrophotometry. It was concluded that acute exposure to Cd has a somewhat different effect on Zn, Cu and Pb storage in the tissues than chronic exposure. It was further inferred that the effects on Zn, Cu and Pb cannot be used as diagnostic criteria in population screenings at very low doses of Cd.

Cadmium content of indicators and target organs after acute Cd exposure

Eleven groups of Wistar rats were given 5 ppm cadmium acetate in the drinking water at different, interrupted periods of their life, simulating acute exposure. The Cd levels of indicators as hair, blood and teeth, and target organs as soft tissues and bone, were recorded by atomic absorption spectrophotometry. It was concluded that Cd passes the placental and mammary barriers; as regards the distribution of Cd in the tissues, the results confirmed previous findings. The results confirmed that rat molars are the best indicator and the most consistent one for past as well as present exposures in rats, but that hair can also be used to some extent as an indicator. The results further indicated that the administration of Cd alone resulted in a lower Cd residue than when Cd was administered concurrently with Pb.

Does cadmium contribute to human hypertension

In 1962 Schroeder reported marked hypertension in rats chronically fed a very low cadmium diet and 5 ppm cadmium in water, but subsequently he reported only moderate hypertension. Using Schroeder's food and water, but a slightly less cadmium-free environment, we repeatedly induced mild hypertension with 5 ppm cadmium, mild because control pressures were higher not because cadmium-fed animals had lower pressures. Seven laboratories have observed hypertension after feeding cadmium; six have not. Thus, chronically fed cadmium can induce hypertension in rats, but conditions are important. Additional observations on cadmium-induced hypertension indicate that: (1) concentrations from 0.1 to 5 ppm cadmium in water are pressor; (2) sex, strain, and age of animals are apparently not limiting factors; (3) there is associated sodium retention; (4) there is a concomitant decrease in the high energy phosphate content of tissues. Rats with cadmium-induced hypertension have renal cadmium concentrations which bracket those of the average environmentally exposed American or European. Finally, renal cadmium concentrations in man were significantly higher ( p < 0.05) for “hypertensives” than for normotensive “matches” in five of nine reported series, lower in one, and similar in three, with all series being small and suboptimal in subject selection.

Monthly deposition of cadmium in rural and industrial areas of Germany (Bayern, Pfalz, Ruhr district) and its influences upon an agricultural model system

Monthly depositions of cadmium were collected by a modified Bergerhoff method and measured by AAS during a 3-year period in rural areas of the Pfalz and in an industrial area of the Ruhr district. Another one year period included measurements in rural areas of southern Bavaria and on a Dutch island. The log-normally distributed deposition rates of cadmium at the rural areas in southern Germany amounted to only 20% of those of the industrial district. The depositions on the Dutch island were twice as high as the depositions on the rural areas of southern Germany. The monthly cadmium deposition rates show only little periodical fluctuation during the year and scatter around more or less constant median values of 25 and 120 μg · m −2 · month −1 at the rural and industrial areas, respectively. When open air mass cultures of algae were taken as an agricultural model, the organisms, depending on their growth rate, accumulated 0.4–4.0 ppm of cadmium (dry matter based). The course of the cadmium accumulation reflects the deposition rate of the area where the algae were grown. No growth depression of the algae due to cadmium can be observed under the given deposition rates.

Waste-related cadmium cycle in Switzerland

The anthropogenic contribution to the global cadmium flux exceeds natural sources by a factor of three. The most important pathway is the atmosphere; therefore, high cadmium concentrations can be found even in remote areas. On a local level, the increase in cadmium consumption can be observed in increasing concentrations in the soil, plants, and food. The question arises as to what extent the soil-plant-man-waste-soil cycle can be loaded with cadmium in order to function without negative impact on the environment. In Switzerland, 120 tonnes (t) of cadmium are consumed per year. Of this amount, 25 t end up in municipal solid waste, 3 t in wastewater, and 19 t in precipitation and dry fallout. As a consequence of today's waste management practice (75% incineration, 20% sanitary landfill, 5% composting; 75% of all sewage is purified), the annual input to the soil is 40 t: 18 t concentrated in landfills, 19 t dissipated via the atmosphere, and 3 t directly spread via sewage sludge, compost, and fertilizer on agricultural land. If even distribution were possible, the cadmium content of the soil would theoretically double in 150 years. The accumulation in the soil will increase the cadmium content of plants grown on such a soil. According to a simple model, the level of 3 ppm cadmium in soils should not be surpassed. At such concentrations, plants are likely to contain > 0.4 mg Cd/kg, a concentration which can cause toxic effects in long-term experiments. The safe level in food might be even lower. In reality, cadmium is not evenly distributed over Switzerland. According to today's practice, it must be assumed that in only 14 years the use of compost will have enriched soils to such an extent that its cadmium content will prohibit the production of food for human consumption. For sewage sludge, this timespan is 130 years. If heavy metal limits in food are to be observed, the input of such metals to the soil has to be limited. In a steady state, the cadmium input to the soil should be equal to its output via plants, leachate, and erosion. This implies that today's dissipative use of cadmium must be stopped.

Decrease and recovery of serum zinc and bone growth of rats with chronic ingestion of 25 ppm and 50 ppm cadmium

Weanling female Wistar rats ingested 25 ppm or 50 ppm cadmium (Cd) as CdCl 2 in water for 330 days. Suppression of body weight gain was observed during the early stages of ingestion. The serum zinc (Zn) concentration from Cd-treated rats was significantly decreased in both groups at 35 days. Cd groups gradually exceeded the control group in body weight gain. At the 330th day of Cd ingestion decreased Zn concentration was observed in the fibula bone, though exchangable serum Zn had almost returned to normal. The decrease of calcium (Ca) and hydroxyproline in fibulae was small. The severe decrease in serum Zn concentration during growing stages did not have a suppressing effect on bone growth. The recovery of body weight gain could be partly explained by the smaller intake of Cd water in adults than in young.

Pathology of lethal and sublethal exposure of fathead minnows,pimephales promelas, to cadmium: A model for aquatic toxicity assessment

Seventy‐six fathead minnows were exposed to 12 ppm cadmium for 96‐ h and examined histologically at 1‐wk intervals for 30 d. Thirteen fish (17.1%) died during the exposure period. Lesions associated with acute cadmium toxicity were epithelial necrosis of the skin, oral cavity, gills, olfactory organs, kidney, urinary bladder, ureters, gastrointestinal tract, and hemopoietic organ. The lesions were most severe in fish which died. Survivors had similar but less severe and less extensive lesions. Residual minimal to mild multifocal necrosis was observed In gastrointestinal, branchial epithelium and and hemopoietic tissue up to 29 d postexposure. Radiotracer studies in 50 fish using 115Cd demonstrated a rapid uptake and two phase elimination of cadmium by the fish. Rapid elimination of cadmium occurred within 7 wk and was correlated with lesions in the urinary epithelium. Slow phase elimination occurred for at least 3 wk and was correlated with persistant minimal necrosis in several tissues.

ALTERED AVOIDANCE BEHAVIOR OF YOUNG BLACK DUCKS FED CADMIUM

Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 4 or 40 ppm cadmium as cadmium chloride. One-week-old ducklings that had been fed the same dietary concentrations of cadmium as had their parents were tested for avoidance of a fright stimulus. Ducklings fed 4 ppm cadmium ran significantly farther from the stimulus than did controls or ducklings fed 40 ppm cadmium. Such an alteration in behavior could have harmful effects on wild birds.

Cadmium modification of the response in Balb/c mice to MOPC-104E tumor.

The immunotoxicological effects of cadmium suggest that it may alter immunosurveillance. However, the studies contributing to this conclusion have been conducted at relatively high cadmium concentrations and for extended periods of exposure. Cadmium was administered in the drinking water of Balb/c mice at 0.01, 0.10, and 1.0 ppm for 4 to 5 wk. Under these conditions, there was a cadmium dose-dependent change in the mortality rate of mice when challenged with an intraperitoneal injection of 5 X 10(3), 5 X 10(4), or 5 X 10(5) MOPC-104E plasmacytoma cells. There was a maximum decrease in mortality at the 0.01 ppm dose level, while at the higher cadmium concentrations there was little or no change. At the two highest tumor cell doses, there was a decrease in the incubation time of the illness in animals exposed to 0.01 ppm cadmium. This returned to control values at the higher concentration of cadmium. The data indicate that at very low concentrations cadmium can alter tumor growth by more than one mechanism that may involve immunocompetence.

Effect of Diet on Increases in Systolic Pressure Induced in Rats by Chronic Cadmium Feeding

Long-term exposure to cadmium in drinking water can induce hypertension in rats. We have consistently observed that from 0.1 to 5 ppm cadmium in deionized drinking water fortified with five essential metals induces a significant pressor effect in female Long-Evans rats on a noncommerical, low cadmium, rye-based diet. To test the effect of diet, a commercial stock diet (Purina Rodent Lab Chow), with either fortified or plain deionized water, was begun at weaning in rats that were receiving water containing 0.1 or 1 ppm cadmium. The overall effect of substituting the stock diet for the rye diet was initially to lessen, and later to prevent entirely, the cadmium-induced pressor effect. Whereas control rats on the rye diet have a constant systolic pressure of about 100 mm Hg throughout the experiment; control rats on the stock diet had an increase in systolic pressure of about 1 mm Hg/month, perhaps because of cadmium from food which contained 10 times as much of the metal as the rye diet. (There was also a somewhat lower pressure among the cadmium-fed rats on stock diet than among those on the rye diet.) There were other (non-cadmium) differences between the stock and rye diets and between the remainder of our experimental conditions and those used by other investigators, presumably explaining the failure of some others to induce hypertension with cadmium.hypertension cadmium cadmium-induced hypertension dietary effect

Cadmium and nickel in smoke of cigarettes prepared from tobacco cultured on municipal sludge-amended soil.

Cigarettes prepared from tobacco grown on municipal sludge-amended soil were smoked, and the mainstream particulates and gaseous fractions were analyzed for total cadmium and nickel content. Sludge-grown and control (soil-grown) tobaccos contained, respectively, 67.4 and 3.18 ppm of cadmium and 19.4 and 1.29 ppm of nickel. The quantities of cadmium (microgram per cigarette) found in the mainstream particulate and gaseous fractions were, respectively, 6.67 and 0.04 for the sludge-grown and 0.21 and 0.03 for the control treatments. The quantities of nickel (microgram per cigarette) found in the mainstream particulates and gaseous fractions were, respectively, 0.11 and 0.07 for the sludge-grown and 0.01 and 0.01 for the control treatments. The potential public health implications of these results and modifying factors are discussed.

Modification of skin-graft rejection and acceptance by low concentrations of cadmium in drinking water of mice.

Skin allograft rejection and isograft acceptance was studied in Balb/c mice exposed to 0, 0.01, 0.1, 1.0, or 10.0 ppm cadmium in drinking water beginning 4 wk prior to grafting. Cadmium exposure was associated with a dose-dependent acceleration of the rejection of allografts prepared from the tail skin of C57/BL mice. The mean time to allograft rejection decreased from 10.4 d in non-metal-exposed recipients to 7.4 d in mice exposed to 10 ppm cadmium. Cadmium exposure was also associated with a dose-dependent increase in the time to isograft acceptance (8.6 d in control mice compared to 11.0 d in mice exposed to 10 ppm cadmium). In addition, some isografts were rejected by animals exposed to 1 or 10 ppm cadmium. It is suggested that a cadmium-induced modification of the wound-healing process could explain both the allograft and isograft response, although an effect of cadmium on the immune response to histoincompatible tissue may also play a role in the accelerated allograft rejection.

Some Metabolic Interrelationships Between Toxic Levels of Cadmium and Nontoxic Levels of Selenium Fed to Rats

Male rats were fed vitamin E-adequate, Torula yeast-based diets for 30 days to assess the influence of dietary selenium (0, 0.1, or 1.0 ppm) on the toxicity of dietary cadmium (0, 30, or 60 ppm). At all selenium levels, increased cadmium intake depressed feed consumption, reduced feed efficiency and lowered body weight gain. In liver, concentrations of cadmium and zinc increased, and iron concentration decreased with increased intake of cadmium. Dietary selenium did not affect concentrations of cadmium, zinc, iron or copper in liver. Blood hemoglobin level declined and relative heart weight (g/100 g body wt) increased with increased intake of cadmium. Increased selenium intake partially alleviated the cadmium-induced depression in blood hemoglobin levels in rats fed diets that contained 30 ppm cadmium, and partially ameliorated the cadmium-induced increase in heart size in rats fed either 30 or 60 ppm cadmium. Hepatic and renal glutathione peroxidase (GSH-Px) activity increased with increased selenium intake. Increased cadmium intake did not affect renal GSH-Px activity. Hepatic GSH-Px activity in rats fed diets that contained 0.1 ppm selenium decreased with increased cadmium intake; however, hepatic GSH-Px activity was not affected by dietary cadmium in rats fed diets that contained 1.0 ppm selenium. Interactions between nontoxic levels of dietary selenium and relatively high levels of dietary cadmium apparently resulted in an antagonism of selenium metabolism by cadmium in some systems, and partial amelioration of cadmium toxicity by selenium in other systems.cadmium-selenium interaction cadmium toxicity glutathione peroxidase

Peripheral effects of cadmium on the blood and head kidney in the brown bullhead (Ictalurus nebulosus).

The study was undertaken to determine the amount and rate of uptake of cadmium via atomic absorption measurements, and to determine whether acute cadmium exposure (61 ppm) provides alterations in the blood and head kidney. The results indicate that the peripheral blood and head kidney of indigenous fish species feeding in the area of the dump provide the best immediate monitor for water quality. The head kidney and peripheral blood coupled with chemical analysis for cadmium indicate that the head kidney may be one of the initial target organs of cadmium toxicity. After an initial 2-h exposure of 61 ppm cadmium, an immediate and 24-h intervals were used to examine the effect, uptake, storage and clearance of cadmium from the peripheral blood and head kidney. (JMT)

EFFECTS OF CADMIUM AND ZINC ON OXYGEN UPTAKE IN THE WHELKBULLIA DIGITALIS(DILLWYN)

SUMMARY Solutions of both cadmium chloride and zinc chloride affect the oxygen intake of Bullia digitalis at 15 °C, the sensitivity to cadmium being about ten times greater than to zinc. Zinc concentrations above 1 ppm result in a lowering of oxygen consumption, uptake being reduced by some 40% at 2 ppm. Cadmium, on the other hand, increases respiration at levels between 0,1 and 0,7 ppm, there being an increase of 30% at 0,5 ppm. Above 0,6 ppm cadmium, oxygen uptake decreases rapidly and is 20% below normal at 0,75, 38% down at 1 ppm. Altering the temperature within the range 10–20 °C has little effect on these responses, while the length of the exposure period has a greater effect. Low concentrations of zinc do not alter the responses to cadmium but at higher concentrations of zinc the effect is additive.

Effect of cadmium on the bone collagen metabolism of rat

Effects of various metals on the chick bone lysyl oxidase activity have been studied. Cadmium and zinc at 5 × 10 −4 m in vitro inhibited the oxidase activity by approximately 62 and 69%, respectively. Iron, magnesium, and copper did not affect the lysyl oxidase activity, whereas manganese and mercury slightly enhanced the activity. When young rats were fed a diet containing 50 ppm cadmium for 6 weeks or 100 ppm for 8 weeks, the bone lysyl oxidase activity was inhibited by approximately 40 and 89%, respectively. The ratio of the amount of soluble bone collagen to that of the total collagen in cadmium-treated rats (50 ppm for 52 weeks) significantly increased compared with that of the control group. These results indicate an inhibitory effect of cadmium on the crosslinking of collagen. However, the lysyl oxidase activity remained unchanged when 50 ppm zinc was administered for 6 weeks to the rats. Cadmium accumulated in small amounts but significantly in the bones of cadmium-treated rats, particularly in the epiphyses rather than diaphyses. Cadmium was also found in the bone extracts prepared from epiphyses of the cadmium-treated rats. A remarkable decrease in the serum copper level was observed in the cadmium-treated rats but the copper contents of both bone and its extract did not change. Histological studies of the bone of cadmium-treated rats (100 ppm for 8 weeks) revealed thin cortices in the tibiae and unusual proliferation, irregular arrangements of resting cartilage cells, and shortening of cartilage cell columns in the epiphyseal plates of the bones.

Metal content, after exposure to cadmium, of two species of earthworms of known differing calcium metabolic activity

Exposure of Lumbricus rubellus and Allolobophora caliginos to 5 ppm cadmium chloride solution for 26 days resulted in accumulation of the metal, but this did not affect the concentrations of iron, zinc, manganese and copper. The naturally occurring difference in calcium concentrations between the species ( L. rubellus > A. caliginosa) also remained unchanged in cadmium-treated earthworms, indicating no cadmium/calcium relationship in either species. The post-clitellar region showed high concentrations of cadmium in the intestinal tissue but this could not be located ultrastructurally. Within the chloragocyte tissue, 70% of the cadmium was in the cell supernatant fraction and only 30% associated with the chloragosomes. An ultrastructural study, using both the conventional glutaraldehyde and the pyroantimonate fixation techniques, showed electron dense deposits within the debris vesicles of the chloragocyte cytoplasm. A technique to distinguish between surface-associated and internalised cadmium in the posterior body wall tissue showed that 68% of the metal of this tissue in L. rubellus was associated with the surface mucus.

Tissue residues of dietary cadmium in wood ducks.

One-week-old wood ducks were fed cadmium in diets containing 18 or 30% protein for a period of three months. Seven drakes from each group were sacrificed, and blood, brain, muscle, kidney, liver, and wing feather tissues were collected and analyzed for cadmium. Highest cadmium concentrations were found in the kidney, liver, and feather tissues; blood, muscle, and brain cadmium residue levels were undetectable. Except in the kidney tissue, protein level of the diet did not affect cadmium residue levels. For birds that were changed to a cadmium-free, high-protein ration at 13 weeks of age, regression analysis indicated a significant decrease in cadmium residue levels for the kidney tissue only. Growth, as measured by bodyweight at 13 weeks of age, was not affected by the various cadmium treatment levels. Histopathological examination revealed lesions in the kidney tissues of the 100 ppm cadmium treatment groups, which were more severe in those birds receiving the 18% protein diet. Vacuolation of the pancreatic acinar cells was observed in all groups, but tended to occur more frequently in the higher cadmium level groups.

The chemical form of cadmium in microsomal and mitochondrial fractions from rat liver and kidney after long term administration of cadmium chloride

Wistar rats were given drinking water containing 250 ppm cadmium (Cd) for 12 months. After excising the kidney and liver, the organs were subfractionated into nuclear, mitochondrial, microsomal and cytosol fractions, and the chemical forms of Cd in the subcellular fractions were examined. Although approx. 90% of the total Cd was present in the cytosol, in the form of metallothionein, 3–5% was also present in the mitochondrial fraction and 5–7% in the microsomal fraction from both organs. Each membrane fraction was washed 3 times and there was no contamination of metallothionein from the cytosol according to Cd/protein ratios. By Sephadex G-75 gel filtration, after solubilizing the particulate fractions with sodium deoxycholate, approx. 89% of Cd in the microsomal fraction and 94% in the mitochondrial fraction eluted with the same retention time as that of metallothionein in both liver and kidney, while the remainder was found in a high molecular weight protein fraction. The Cd eluted with the high molecular protein fraction might be involved in dysfunctions in subcellular organelles.

The significance of the cadmium species in uptake and metabolism of cadmium in crop plants

Abstract The uptake of cadmium‐115 by intact seedlings of maize vas investigated with respect to time, concentration and interactions with various cations. An appreciable fraction of the cadmium absorbed by the roots was displaced by desorption and consequently constitutes the exchangeable fraction. Only a small proportion of the cadmium was absorbed in the presence of calcium indicating that this fraction is taken up predominantly by metabolically mediated processes. The transport of cadmium to the shoots was markedly reduced by the addition of zinc to the culture solution. The effects of supplying various cadmium compounds to barley seedlings were investigated hydroponically at a concentration of 0.5 ppm cadmium. Dry weights, mean longest lengths and cadmium, zinc and iron concentrations of root and shoot material were established per treatment. No visible growth effects were noted in any of the treatments. Significant concentrations of cadmium were found in all plants ranging from high concentrations a...