Occupational respiratory diseases in workers engaged in nickel production

Introduction. Upgrading of nickel production technologies, in this case the transition from electrolytic to more modern electroextractive refining, is not always accompanied by an improvement in the working conditions in the employees involved. The aim of the study. To analyze working conditions and occupational respiratory diseases in workers at electrolytic and electroextractive nickel production. Materials and methods. We studied the data of industrial control at nickel industry enterprises and the Murmansk regional register of occupational diseases for 2004–2023. Results. A comparative analysis of hygienic data revealed a 2.4-3.5-fold decrease in the concentration of nickel hydroaerosols at the electrolytic bath operator workplaces and a 4.4–31.4-fold increase in chlorine concentrations in the workplace air of the hydrometallurgical department during the transition to electroextractive refining. Clinical studies have shown the transition to electroextraction method to be accompanied by a decline in the number and in the proportion of workers with occupational respiratory diseases (p=0.002–0.003), a 24.5% decrease in the level of occupational morbidity (from 56.12 cases to 42.35 cases per 10,000 workers), a decrease in the risk of developing respiratory occupational diseases (OR=1.89; 95% CI 1.31–2.73). Over 10 years, only one case of acute chlorine poisoning was registered. Conclusion. We have no found adverse impact of elevated chlorine concentrations on the development of occupational respiratory diseases in workers engaged in electrowinning nickel refining. However, further improvement of nickel electrowinning technology is necessary to reduce the concentration of nickel and chlorine salt hydroaerosols, as well as more effective personal respiratory protection equipment is needed. The impact of working conditions on workers’ health during electrowinning nickel refining requires a longer study.