PubMed · 4882721
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R C Nairn. 1968. Standardization in immunofluorescence.. https://pubmed.ncbi.nlm.nih.gov/4882721/
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Chromium holds a frequent and important place in toxicological literature. The large number of more or less important toxicological facts (e.g. allergic dermatoses, ulcer, perforations of the nasal septum, bronchitis, cancerogenity etc.) are the reason why chromium is conceived rather as a toxic element. On the other hand in the non-toxicological literature favourable actions of chromium are described (its relationship to carbohydrate utilization, the glucose tolerance factor, diabetes etc.) which may induce us to consider chromium an essential element. Is chromium toxic or essential? It is both. The concept of essential or toxic cannot be conceived statically, these terms are relative and depend on a number of other facts and data (dose, time, chemical form, individuality of the organism, interaction with other substances in the environment etc). This relative view has a more general validity not only for chromium but for trace elements in general and it is very important in particular with regard to prevention of health damage caused by deficiency or excess of a substance.
Hexavalent chromium is a known carcinogen. Previous epidemiologic studies in the 1950s of United States workers from seven facilities producing chromium compounds from chromite ore have reported a markedly increased risk for dying from lung cancer. As part of a high risk notification project of workers from four of these facilities, a mortality study was performed. The cohort was assembled in 1990-1991 from the Social Security records of four former chromate producing facilities in northern New Jersey. The study subjects were known to have worked at these facilities some time between 1937 and 1971. Proportionate mortality and proportionate cancer mortality ratios (PCMR) were calculated. The overall risk for lung cancer was a PCMR of 1.51 (confidence limits [CL] 1.29-1.74) for white men and 1.34 (CL 1.00-1.75) for black men. These risks increased with increasing duration of employment and latency since time of first employment. The PCMR for greater than 20 years duration of work and more than 20 years since first exposure was 1.94 (CL 1.15-3.06) for white men and 3.08 (CL 1.13-6.71) for black men. The risk for lung cancer for white men remains elevated more than 20 years after exposure has ceased (PCMR, 1.29; CL 1.03-1.60). The PCMR for nasal cavity/sinus cancer was also found to be a significantly increased, 5.18 (CL 2.37-11.30). A cluster of bladder cancer was seen among black workers from one facility, (PCMR, 3.30; CL 1.42-6.51). Despite the cessation of exposure, former chromium workers remain at significantly increased risk of lung cancer. Although there have been case reports of nasal cavity/ sinus cancer in association with chromium exposure, this is the first epidemiologic study to report a significant increase in these cancers. Limitations in this study include lack of exposure data and lack of information on smoking habits. The lack of increase in other smoking-related diseases besides lung cancer indicates that the increase in lung cancer cannot be attributed to cigarette smoking. The ongoing elevated risk of lung cancer after cessation of exposure emphasizes the need for developing early detection texts for lung cancer.
Increased pancreatic beta-cell secretory activity usually is associated with decreased alpha-cell activity; stimulated beta-cells release gamma-aminobutyric acid, which hyperpolarizes alpha-cells, inhibiting glucagon release. Thus, insulin secretion and glucagon secretion are usually inversely coupled. This suggests that chromium and other insulin-sensitizing modalities, by down-regulating beta-cell activity, may increase glucagon secretion. Such an effect might play a role in the documented therapeutic activity of supplemental chromium and biguanides in reactive hypoglycemia, and might also be of benefit to dieters.