Criteria cadmium

Proposed cadmium criteria for the protection of living resources and human health... 

Table 1.8 Proposed Cadmium Criteria for the Protection of Living Resources and Human Health Resource, Criterion, and Other Variables Effective Concentration Ref.a... 

The radius ratios for sphalerite and wurzite type crystals with eighteen-shell cations do not conform to our criterion, so that some other influence must be operative. Without doubt this is deformation. Here again it is seen that the tetrahedral structure is particularly favorable to deformation, for the observed Zn++—O distance (1.93 A.) is 0.21 A. shorter than the theoretical one, while in cadmium oxide, with the sodium chloride structure, the difference is only 0.01 A. 

DPE suits, and butyl rubber (NRC, 2001b). The levels were 0.0002 to 0.0008 ng/m3, three orders of magnitude below the EPA criterion of 0.2 ng/m3 for dioxin emissions from incinerators. In the test with neat GB, the product gas contained 0.01 to 0.06 percent phosphine. As noted previously in the section on methods development testing, phosphine can interfere with the measurement of GB. Based on results from the EPA s toxicity characteristic leachate procedure, stabilization would be necessary only for solid wastes derived from DPE suit material, because the cadmium and lead criteria were not met by the treated dunnage in some tests (NRC, 2001b). 

Enhancement of POD-capacity and appearance of new isoforms is generally considered as an important criterion for senescence (Hazell and Murray, 1982). Lee et al. (1976a) suggested that the cadmium-induced capacity increase of POD and several hydrolytic enzymes (ribonuclease, deoxyribonuclease, acid phosphatase) in Glycine max should constitute an accelerated senescence response. In Zea mays, an induction of leaf acid phosphatase was also reported for toxic concentrations of lead (Maier, 1978 b). 

The CLEA cadmium soil guideline value (SGV) for residential land use (without plant uptake) of 30 mg/kg is the criterion being used to assess the samples. 

A closely analogous state of affairs is seen in the systems NiTe2-NiTe and TiTe2-TiTe, in which the AB2 compound has the cadmium iodide structure and the AB compound that of nickel arsenide. In both of these structures the B atoms are arranged as in hexagonal close-packing, but in other respects the relationship between them is precisely the same as that between the cadmium chloride and sodium chloride structures, so that solid solution can take place by the same mechanism. Examples such as this, and many others which could be quoted, emphasize that solid solution is in no sense a satisfactory criterion for isomorphism, and that substances may form solid solution even if their structures are formally quite different. 

Heavy metals belong to the group of harmful inorganic contaminants. They are released in the environment from factories and coal-burning power plants and do not naturally decompose in the environment [43]. Currently, they are regulated and, for instance, in freshwater US EPA sets maximiun allowed concentrations for heavy metals such as cadmium (chronic criterion... 

The hosts that we have discussed to date have been ionic in nature, and dielectric as well (they are non-conductive). There is also another class of phosphor hosts which are covalent and semi-conductive in nature, namely the zinc and cadmium sulfides and/or selenides. The criterion for selection of a semi-conducting host for use as a phosphor includes choice of a composition with an energy band gap of at least 3.00 ev. This mandates the use of an optically inactive cation, combined with sulfide, selenide and possibly telluride. The ojq gen-dominated groupings such as phosphate, or silicate or arsenate, etc. are not semi-conductive in nature. And, none of the other transition metal sulfides have band gaps sufficiently... 

From the viewpoint of chemical and physical requirements the permissible indicators involve a number of criteria mercury, selenium, cadmium, vanadium, chromium, arsenic, silver, lead, barium, cyanides, hydrogen sulphide, fluorides, phenols, oil and oil substances, COD(Mn), colour, odour, taste and turbidity. The most stringent criterion concerns the content of mercury, followed by selenium, cadmium, vanadium, cyanides, oil and oil substances. Another important indicator is the content of organic matters characterized by COD(Mn). 

Resource, Criterion, and Other Variables Effective Cadmium Concentration... 

Since 1970, a number of reports have suggested that several metals present In minute quantities in animal tissues are essential nutrients. The trace metals include cadmium, lead, nickel, tin and vanadium. Findings suggesting that cadmium, lead and tin are essential have come from one laboratory and have not been confirmed in another laboratory. Minor growth depression in suboptimally growing rats was the main criterion for demonstrating the essentiality of cadmium, lead and tin. 

Criteria 6—8 are interconnected with the coherence criterion and are similarly answered in the affirmative. Criterion 9, effect analogies in the epidemiological and toxicological literature, can generally be said to exist with other toxic metals, e.g., cadmium and inorganic/methyl mercury. 

A further selection criterion is provided by the different limit temperatures in the electrolyte, as is also depicted in Table 3.2. The use of a particular battery system becomes questionable when the ambient temperature approaches its maximum permissible temperature. Nickel/cadmium batteries have a significantly lower limit temperature than lead-acid batteries. The systems thus dictate that lead-acid batteries should exclusively be used when the ambient temperature exceeds 35 °C to 40 °C. In the case of extreme ambient temperatures, however, a renewal of batteries should also be planned for, in order not to jeopardize the long service life typical of the system, even when using tubular plate batteries. 

The first criterion bases on sulfur dioxide, nitrogen dioxide, carbon monoxide, benzene, ozone, particulate matter PM 10, lead, arsenic, cadmium, nickel and benzo(a)pyrene contained in PM 10, particulate matter PM2,5. Second criterion uses sulfur dioxide, nitrogen oxides and ozone. Highlighted... 

---