Cadmium deficiency

More evidence for the essentiality of cadmium is now available after the ten-fold repetition of the cadmium-deficiency experiments with growing, pregnant and lactating goats and their kids, and the discovery of a cadmium-specific carboanhydrase in the diatom Thallasia sir a weissflogii (Strasdeit... 

The normative cadmium requirement of goats and animals amounts to 20 jg kg DM. Primary cadmium deficiency is not to be expected in animals and humans, as the normal intake is considerably above this range (Kronemann et al. 1982, Anke et al. 1994a). 

Anke M, Groppel B, Schmidt A and Kronemann H (1986b) Cadmium deficiency in ruminants. In Anke M, Baumann W, Braunlich H, Bruckner CHR and Groppel B, eds. 5. Spurenelement-symposium Univ. Leipzig and Jena, pp. 937— 946. 

Larsson S-E, Piscator M (1971) Effect of cadmium on skeletal tissue in normal and cadmium.deficient rats. Isr. J. Med. Sci. 7 495-497 Molin L, Wester PO (1976) The estimated daily loss of trace elements from normal skin by desquamation. Scand. J. Clin. Lab. Invest. 36 679-682 Nordberg GF, Kjellstrom T (1979) Metabolic model for cadmium in man. Environ. Health Perspect. 28 211-217... 

Hi) Poly amines. In many respects the role of poly amines in plant functioning is still mysterious after many years work. They are almost certainly involved in the control of growth and development through their interactions with nucleic acids and membranes (Smith, 1985). There is increasing circumstantial evidence for their involvement, especially of putrescine, in plant responses to a wide range of stresses including pH, Mg deficiency, osmotic shock, cold, SO2 pollution, and cadmium and ammonium toxicity (Smith, 1985). It remains to be determined, however, how, and indeed whether, putrescine accumulation in response to these diverse stresses is beneficial. 

Most trace metals may be precipitated with phosphate into insoluble metal phosphates (Table 7.5). Most metal phosphates have low solubility. High localization of phosphates reduces the bioavailability of Zn in arid soils. The banded application of P near the seeds depresses Zn uptake by com (Adriano and Murphy, 1970 Grant and Bailey, 1993), causing Zn deficiency. However, both N and P fertilizers increase Cd concentration in plants. Cadmium and Zn are antagonistic in root uptake and distribution within plants. 

Sublethal effects in birds are similar to those in other species and include growth retardation, anemia, renal effects, and testicular damage (Hammons et al. 1978 Di Giulio et al. 1984 Blus et al. 1993). However, harmful damage effects were observed at higher concentrations when compared to aquatic biota. For example, Japanese quail (Coturnix japonica) fed 75 mg Cd/kg diet developed bone marrow hypoplasia, anemia, and hypertrophy of both heart ventricles at 6 weeks (Richardson et al. 1974). In zinc-deficient diets, effects were especially pronounced and included all of the signs mentioned plus testicular hypoplasia. A similar pattern was evident in cadmium-stressed quail on an iron-deficient diet. In all tests, 1% ascorbic acid in the diet prevented cadmium-induced effects in Japanese quail (Richardson et al. 1974). In studies with Japanese quail at environmentally relevant concentrations of 10 pg Cd/kg B W daily (for 4 days, administered per os), absorbed cadmium was transported in blood in a form that enhanced deposition in the kidney less than 0.7% of the total administered dose was recovered from liver plus kidneys plus duodenum (Scheuhammer 1988). 

Chromium has proved effective in counteracting the deleterious effects of cadmium in rats and of vanadium in chickens. High mortality rates and testicular atrophy occurred in rats subjected to an intraperitoneal injection of cadmium salts however, pretreatment with chromium ameliorated these effects (Stacey et al. 1983). The Cr-Cd relationship is not simple. In some cases, cadmium is known to suppress adverse effects induced in Chinese hamster (Cricetus spp.) ovary cells by Cr (Shimada et al. 1998). In southwestern Sweden, there was an 80% decline in chromium burdens in liver of the moose (Alces alces) between 1982 and 1992 from 0.21 to 0.07 mg Cr/kg FW (Frank et al. 1994). During this same period in this locale, moose experienced an unknown disease caused by a secondary copper deficiency due to elevated molybdenum levels as well as chromium deficiency and trace element imbalance (Frank et al. 1994). In chickens (Gallus sp.), 10 mg/kg of dietary chromium counteracted adverse effects on albumin metabolism and egg shell quality induced by 10 mg/kg of vanadium salts (Jensen and Maurice 1980). Additional research on the beneficial aspects of chromium in living resources appears warranted, especially where the organism is subjected to complex mixtures containing chromium and other potentially toxic heavy metals. 

Devineau, J. and C. Amiard Triquet 1985. Patterns of bioaccumulation of an essential trace element (zinc) and a pollutant metal (cadmium) in larvae of the prawn Palaemon serratus. Mar. Biol. 86 139-143. Dib, A., J.P Clavel, and J.P. Carreau. 1989. Effects of gamma-linolenic acid supplementation on lipid composition of liver microsomal membranes. I. Pregnant rats fed a zinc-deficient diet and those fed a balanced one. Jour. Clin. Biochem. Nutr. 6 95-102. 

Sato, M. and Y. Nagai. 1989. Effect of zinc deficiency on the accumulation of metallothionein and cadmium in the rat liver and kidney. Arch. Environ. Contam. Toxicol. 18 587-593. 

Pichat S, Douchet C, Albarede F (2003) Zinc isotope variations in deep-sea carbonates from the eastern equatorial Pacific over the last 175 ka. Earth Planet Sci Lett 210 167-178 Price NM, Morel EMM (1990) Cadmium and cobalt substitution for zinc in a zinc-deficient marine diatom. Nature 344 658-660... 

Toxicity of cadmium increases in cases of zinc deficiency, due to the zinc substitution in biological systems, which leads to functional disorders. Cadmium reduces assimilation of vitamins C and D. However, a large amount of these vitamins in the diet will decrease the toxicity of cadmium through the reduction of its absorption from the intestinal tract (Friberg et ah, 1986 Hill, 1996 McLaughlin et ah, 1999). 

Human food, both plant and animal, usually contains satisfactory amounts of zinc to cover the requirement for this metal, which is present within the range of few to several pg per g of product. Zinc deficiencies are usually caused by a reduction of its absorption in the gastrointestinal tract rather than by its lack. Reduction in absorption may be caused by antagonistic activity of cadmium, calcium or phytates. A decrease in assimilation of zinc is also observed among alcoholics. 

Selenium is readily available in a variety of foods including shrimp, meat, dairy products, and grains, with a recommended daily intake of 55 to 70 jug. It occurs in several forms with Se+6 being biologically most important. Selenium is readily absorbed by the intestine and is widely distributed throughout the tissues of the body, with the highest levels in the liver and kidney. It is active in a variety of cellular functions and interacts with vitamin E. Selenium appears to reduce the toxic effects of metals such as cadmium and mercury and to have anticarcinogenic activity. Selenium produces notable adverse effects both in deficiency and excess thus recommended daily intake for adults is approximately 70 Jg/day but should not exceed 200 pg/day. 

Contraindications Acute renal impairment, organic (short-chain alkyl) mercury poisoning, G6PD deficiency (unless a life-threatening situation exists), hepatic insufficiency (unless due to arsenic poisoning), use of iron, cadmium or selenium poisoning, hypersensitivity to dimercaprol or any component of the formulations... 

Both compounds crystallize with the cadmium diiodide structure (space group P3ml) as previously reported on polycrystalline samples.3 For platinum disulfide, ao = 3.542(1) A and c0 = 5.043(1) A, and for platinum ditelluride, a0 = 4.023(1) A and c0 = 5.220(3) A. Direct chemical analysis for the component elements was not carried out. Instead, precision density and unit-cell determinations were performed to characterize the samples. The densities of both compounds as determined by a hydrostatic technique with heptadecafluorodeca-hydro-l-(trifluoromethyl)naphthalene as the density fluid4 indicated that they are slightly deficient in platinum. For platinum disulfide, = 7.86 g/cm3 and Pmeas = 7.7(1) gm/cm3, and for platinum ditelluride, p = 10.2 gm/cm3 and Pmeas = 9.8(1) gm/cm3. In a typical experiment an emission spectrum of the platinum disulfide showed that phosphorus was present in less than 5 ppm. A mass spectroscopic examination of the platinum ditelluride revealed a small doping by sulfur (less than 0.4%) and traces of chlorine and phosphorus (less than 100 ppm). 

The Swedish government s announced intentions to ban all uses of cadmium, including in recyclable accumulators, may, in fact, increase health and environmental risks. Cadmium is always present in zinc, and it is obtained from the purification of that metal. If no sensible use can be found for cadmium, the producers will simply leave it in the zinc, resulting in extensive and diffuse emission of cadmium from corroding zinc that will be impossible to control. The regulators answers to the problems presented by cadmium-laden zinc are attempts to curb uses of zinc as well, in spite of the fact that deficiency of the essential element zinc is a public health problem. 

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