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Sophus Mads Jørgensen (1837-1914) was one of the important chemists of the second half of the XIX century and the first decade of the XX century. He was one of the founders of the chemistry of complex compounds. He also made major contributions to the chemistry of platinum, cobalt, chromium and rhodium compounds. The purpose of this paper is to familiarize readers with the important events in the life of Jørgensen and his writing activities, in particular with his chemistry books. In addition, his research activities are briefly described. [ABSTRACT FROM AUTHOR]

This paper provides a short overview of cobalt-related diseases with particular reference to the potential carcinogenicity of cobalt compounds, and a review of a 10-year surveillance programme on plate painters exposed to cobalt in two Danish porcelain factories. Clinical experience and epidemiological studies have demonstrated that cobalt exposure may lead to severely impaired lung function, i.e. hard metal lung disease and occupational cobalt-related asthma, contact dermatitis and cardiovascular effects. However, the evidence for the carcinogenicity of cobalt and cobalt compounds is considered inadequate (IARC, 1991). Most frequently, exposure to cobalt occurs simultaneously with exposure to other elements known to pose a health risk, (e.g. nickel, arsenic, chromium, tungsten). The importance of cobalt as sole causal agent in hard metal lung diseases, cardiomyopathy and cancer are still a matter of controversy. In the two Danish porcelain factories, cobalt blue underglaze dyes have been used since 1888. In contrast to the exposure experience of hard metal factories, the exposure of plate painters occurs with only low trace levels of other potentially harmful compounds such as the carcinogenic metals nickel, arsenic and chromium. Consequently, the nearly-pure cobalt exposure makes the plate painters an attractive group for studies on the health effects of cobalt. During the period 1982-1992 the surveillance programme showed a profound reduction in the urine level of cobalt (Co-U) from 100-fold to 10-fold above the median level of the unexposed control subjects. In the same period, the airborne cobalt exposure declined from 1356 nmol/m3 to 454 nmol/m3, the Danish occupational exposure limit being 845 nmol/m3. In 1982, when the cobalt exposure was above the occupational exposure limit, the plate painters showed a chronic impaired lung function. The obstructive effects may be similar to some of the effects observed in hard metal workers. In 1988, a study on the effect of cobalt exposure at low levels revealed no inhibitory effects on thyroid function, but the ratio between T4 and T3 increased, indicating that low cobalt exposure may have an impact on the metabolism of thyroid hormones. Parallel studies were conducted on the metabolism and excretion of cobalt. The gastrointestinal uptake of soluble CoCl was considerably higher than the uptake of insoluble cobalt(II) oxide. In addition, it was demonstrated that ingestion of controlled amounts of the soluble cobalt compound resulted in significantly higher concentrations of cobalt in urine and blood (Co-B) from females compared with males (P < 0.01). Future studies will involve epidemiology and genotoxicity to evaluate the previous and present cancer risk, and detailed process-related exposure assessment studies to select the methods most reliable for surveillance of low-dose cobalt exposure.

Background: Chromium and cobalt are important skin sensitizers. It has, however, been difficult to identify causative exposures. Studies on nickel allergy have demonstrated piercing as critical for both sensitization and elicitation. It may be speculated that the same applies for chromium and cobalt. Objective: To examine the content and release of chromium and cobalt from earrings randomly purchased in Denmark. Methods: Three hundred four earrings were examined with x‐ray fluorescence (XRF) spectrometry. Earrings with measured content of chromium or cobalt were spot tested with diphenylcarbazide spot test (n = 166) or Nitroso‐R spot‐test (n = 99), respectively. Chromium and cobalt release were quantified in a selected subsample (n = 100) with the artificial sweat test (EN 1811). Results: Chromium was present in 54.6% (166/304) of earrings and cobalt was present in 72.0% (219/304),− measured by XRF. All chromium spot tests for chromium VI were negative. The cobalt spot test was positive for one component. Chromium release was found from 59/100 (median concentration = −0.06 μg/cm2/week) and cobalt release from 29/100 (median concentration = −0.06 μg/cm2/week) of earrings in tested subsample. Conclusion: Earrings for piercing release chromium and cobalt and may on a case basis be a source of chromium and cobalt allergy. [ABSTRACT FROM AUTHOR]

Background: The metal-on-metal large-diameter-head (MoM-LDH) hip replacements increased in popularity during the start of the twenty-first century. Subsequently reports raised concerns regarding adverse reactions due to elevated chromium (Cr) and cobalt (Co) concentrations as well as high rates of other complications and revisions. The purpose was to compare Harris Hip Score and SF-36 at 5-years follow up following MoM-LDH total hip arthroplasty (MoM-LDH-THA) or MoM hip resurfacing (MoM-HR).Methods: The study was conducted between November 2006 to January 2012 in a tertiary health care center in Denmark. Patients with primary or secondary osteoarthritis were randomly assigned to receive a Magnum (MoM-LDH-THA) or a Recap (MoM-HR) prosthesis. Randomization was computer generated and allocation was concealed in an opaque envelope. Neither patients nor care provider were blinded. Primary outcome was Harris Hip Score at 5-years follow up.Results: Seventy-five were included and allocated to the MoM-LDH-THA (n = 39) and MoM-HR (n = 36) group. The study was prematurely stopped due to numerous reports of adverse events in patients with MoM hip replacements. Thirty-three in the MoM-LDH-THA and 25 in the MoM-HR group were available for primary outcome analysis. Median Harris Hip Score was 100 (IQR: 98-100) for MoM-LDH-THA and 100 (IQR: 93-100) for MoM-HR (p = 0.486). SF-36 score was high in both groups with no significant difference between groups.Conclusion: Harris Hip Score and SF-36 score was excellent in both groups with no significant difference at 5-years follow up. Our findings suggest that there is no clinical important difference between the two prostheses implanted 5 years after implantation.Trial Registration: ClinicalTrials.gov, NCT04585022 , Registered 23 September 2020 - Retrospectively registered. This study was not prospectively registered in a clinical trial database since it was not an entirely implemented standard procedure in the international orthopedic society when the study was planned. [ABSTRACT FROM AUTHOR]