Chromium environment

Norseth, T. 1981. The carcinogenicity of chromium. Environ. Health Perspect. 40 121-130. 

Johansson A, Curstedt T, Robertson B, et al. 1989. Lung lesions after experimental combined exposure to nickel and trivalent chromium. Environ Res 50 103-119. 

AlbertRE. 1991. Issues in the risk assessment of chromium. Environ Health Perspect 92 91-92. 

Johansson A, Robertson B, Curstedt, et al. 1986a. Rabbit lung after inhalation of hexa- and trivalent chromium. Environ Res 41 110-119. 

Tandon SK, Saxena DK, Gaur JS, et al. 1978. Comparative toxicity of trivalent and hexavalent chromium. Environ Res 15 90-99. 

Witmer C, Faria E, Park H-S, et al. 1994. In vivo effects of chromium. Environ Health Perspect 102(3) 169-176. 

Jeen, S. W., Jambor, J. L., Blowes, D. W., Gillham, R. W. Precipitates on granular iron in solutions containing calcium carbonate with trichloroethene and hexava-lent chromium. Environ. Sci. Techn., 41,1989-1994 (2007). 

Alexandrite, like ruby, contains Cr ions but they are substituted in the lattice of chrysoberyl, BeAl204. The chromium ions occupy two symmetrically non-equivalent positions which would otherwise be occupied by aluminium ions. In this environment the 2 ground state of Cr is broadened, compared with that in ruby, by coupling to vibrations of the crystal lattice. 

Coalition ofJSlortheast Governors. The CONEG model heavy-metal guideline is implemented through state regulations and limits total metal content of lead, chromium, mercury, and cadmium. The limitation of 100 parts per million total is aimed at protecting the environment from the disposal of post-consumer waste. 

Molybdenum improves the corrosion resistance of stainless steels that are alloyed with 17—29% chromium. The addition of 1—4% molybdenum results in high resistance to pitting in corrosive environments, such as those found in pulp (qv) and paper (qv) processing (33), as weU as in food preparation, petrochemical, and poUution control systems. 

Corrosion Resistance of the Austenitic Chromium—Mickel Stainless Steels in Chemical Environments, Inco Limited, Nickel Development Institute, Toronto, Ontario, Canada, 1963. 

Acute and Chronic Toxicity. Although chromium displays nine oxidation states, the low oxidation state compounds, -II to I, all require Special conditions for existence and have very short lifetimes in a normal environment. This is also tme for most organ ochromium compounds, ie, compounds containing Cr—C bonds. Chromium compounds that exhibit stabiUty under the usual ambient conditions are limited to oxidation states II, III, IV, V, and VI. Only Cr(III) and Cr(VI) compounds are produced in large quantities and are accessible to most of the population. Therefore, the toxicology of chromium compounds has been historically limited to these two states, and virtually all of the available information is about compounds of Cr(III) and/or Cr(VI) (59,104). However, there is some indication that Cr(V) may play a role in chromium toxicity (59,105—107). Reference 104 provides an overview and summary of the environmental, biological, and medical effects of chromium and chromium compounds as of the late 1980s. 

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