Zinc deficiency

The chloride and chromate are also important compounds. Zinc is an essential element in the growth of human beings and animals. Tests show that zinc-deficient animals require 50 percent more food to gain the same weight as an animal supplied with sufficient zinc. 

In paints, zinc oxide serves as a mildewstat and acid buffer as well as a pigment. The oxide also is a starting material for many zinc chemicals. The oxide supphes zinc in animal feeds and is a fertilizer supplement used in zinc-deficient soils. Its chemical action in cosmetics (qv) and dmgs is varied and complex but, based upon its fungicidal activity, it promotes wound healing. It is also essential in nutrition. Zinc oxide is used to prepare dental cements in combination with eugenol and phosphoric and poly(acrylic acid)s (48) (see Dental materials). 

In addition to their endocrine disrupting properties, it must be appreciated that many of the chemicals in question possess more general toxic properties, which may be potentiated by metabolism by the organism. Several PAHs, PCBs and PCDDs are carcinogenic, while certain phthalate esters can enhance the excretion of zinc, potentially leading to zinc deficiency. Zinc, an essential element, plays a vital role in spermatogenesis and mature T-cell production. Deficiency may result in abnormalities of the male reproductive system, depletion of spermatogenesis and suppression of the immune system. 

In spite of careful analysis of the products with the various sophisticated probes, differences in the composition are reported. All measurements indicate a zinc-deficient zinc ferrite, but the indicated zinc concentration varies from 0.2 to 0.9. The EDS measurements are based on direct zinc concentration measurements. Determinations based on magnetization and Mdssbauer spectra are obtained on zinc ferrite synthesized in more conventional processes. 

Cakmak and H. Marschner, Increase in membrane permeability and exudation in roots of zinc deficient plants. J. Plant Physiol. 132 356 (1988). 

I. Cakmak, B. Erenoglu, K. Y. Giiliit, R. Derici, and V. Romheld, Light-mediated release of phytosiderophores in wheat and barley under iron or zinc deficiency. Plant Soil 202 309 (1998). 

Presence of malnutrition and diarrhea can lead to zinc deficiency... 

The lack of zinc can also be a problem in biological systems and is responsible for disease states. For example, nitric oxide-dependent apoptosis can be induced in motor neurons by zinc-deficient SOD, and in some cases of amyotrophic lateral sclerosis, zinc-deficient SOD may participate in this type of oxidative mechanism involving nitric oxide.969 One form of hereditary human hair loss or alopecia was mapped to a specific gene and a mutation found in affected individuals. The gene encodes a single zinc finger transcription factor protein with restricted expression in the brain and skin.970 Zinc has been implicated in Alzheimer s via beta amyloid formation, and a role has been attributed for the cerebral zinc metabolism in the neuropathogenesis of Alzheimer s disease.971... 

Bushnell PJ, Levin ED. 1983. Effects of zinc deficiency on lead toxicity in rats. Neurobehav Toxicol Teratol 5 283-288. 

For some trace elements (e.g., Zn and Cu), high organic matter leads to Zn/Cu deficiency. Zinc deficiency has been observed in muck or peat soils... 

Table 7.4. Zinc sources and application rates for correcting zinc deficiency on crops3...

A common critical limit for Zn deficiency in soils has been 0.5 mg/kg DTPA-extractable Zn for different crops (maize, wheat, and rice) (Sillanpaa, 1982). DTPA-extractable Zn concentration of 0.5-1.0 mg/kg has been marginal for sensitive crops (Sillanpaa, 1982). Brown isohumic calcareous soils of New South Wales in Australia with 35-60 mg/kg of total Zn showed Zn deficiency due to the low bioavailability of Zn. Zinc deficiency has been reported to occur in wheat on solidized solonetz and solodic soils and other calcareous soils of South Australia. Zinc application at the rate of 0.6-28 kg/ha to cereals, pastures, and maize of Australia has been reported (Reuter, 1975). Zn deficiency occurs in Turkey, India, Iraq, Mexico, and Pakistan (Table 7.8). Zinc deficiency is frequently observed in rice on calcareous paddy soils. 

Hopkins B.G., Whitney D.A., Lamond R.E., Jolley V.D. Phytosiderophore release by sorghum, wheat, and com under zinc deficiency. J Plant Nutri 1998 21 2623-2637. 

Estevez, A. G.,Crow, J. P., Sampson, J. B. etal. Induction of nitric oxide-dependent apoptosis in motor neurons by zinc-deficient superoxide dismutase. Science 286 2498-2500,... 

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). 

Zinc deficiency places an increased demand on selenium (Se) pools in daphnids. As little as 5 pg Se/L in zinc-free water eliminated overt cuticle damage and substantially increased reproduction, but did not alter the shortened life span. Cladocerans at the threshold of Se deficiency will become overtly Se deficient when zinc supplies are lacking (Keating and Caffrey 1989). Insufficient copper introduces cuticle problems in daphnids similar to those introduced by insufficient zinc or... 

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