Occupational Health Risks in Electrolytic Refining and Electrowinning of Nickel

Introduction: High incidence of occupational diseases in workers is one of the reasons for the introduction of novel, safer technologies for nickel production. Objective: To study workers’ health risks posed by electrolytic refining and electrowinning of nickel. Materials and methods: We studied industrial control data at a nickel industry enterprise and the Murmansk regional register of occupational diseases for 2004–2023. Results: In 2004–2013, nickel was produced using electrolysis, while in 2014–2023, this technique was substituted by electrowinning. Such a transition was accompanied by a 2.5 to 3.5-fold decrease in time-weighted average concentrations of nickel water aerosols in the electrolysis departments and a 4.4-fold increase in chlorine concentration in the hydrometallurgy departments. Over 20 years, 311 occupational diseases were registered in workers of this refinery, particularly electrolysis bath operators (31.7 %), among which respiratory diseases predominated (60.1 %). Compared to 2004–2013, we observed a decrease in the incidence rate by 14.1 % (from 86.67 to 75.88 cases per 10,000 workers) and a lower risk of developing a disease (OR = 1.45; 95 % CI: 1.04–2.02) in the years 2014 to 2023. Both techniques pose high, very high, and extremely high workplace health risks and an unacceptable cancer risk (≥ 1.0×10–3). Only one case of acute chlorine poisoning was registered in 2019. Conclusion: Switching from electrolytic refining to electrowinning of nickel does not increase health risks at the workplace. However, the previously existing and persisting high, very high, and extremely high occupational risks, as well as the unacceptable carcinogenic risk for most jobs indicate the priority of introducing new health-maintaining technologies for workers in the nickel industry after technological upgrade (personal protective equipment, working time reduction, etc.).