Occupational disease claims and non-occupational morbidity in a prospective cohort observation of nickel electrolysis workers

Abstract

Exposure to nickel aerosol in the nickel production is associated with greater occupational risk, yet little is known how many workers will develop an occupational disease and claim compensation. The aim of this analysis was to prospectively observe a cohort of nickel electrolysis workers and quantitatively assess confirmed occupational disease claims. We observed a cohort of nickel electrolysis workers (N = 1397, median age 39, 68% males) from 2008 till 2020 in one of the largest nickel producers in the Russian High North. Cumulative incidence of confirmed occupational disease claims in seven occupational groups, including electrolysis operators, hydrometallurgists, crane operators, final product cleaners, metalworkers, electricians and ‘other’ was analyzed and supplemented with Cox proportional hazards regression, yielding hazard ratios (HR) with their 95% confidence intervals (CI) of occupational disease claims for each group. N patients with occupational disease claims varied from 1 in 2016 to 22 in 2009, and in total 87 patients developed one or more occupational diseases (cumulative incidence 6.2%, p < 0.001 between seven groups). Accounting for 35,527 person-years of observation in total, cleaners exhibited the greatest risk (HR 2.58 (95% CI 1.43–4.64)), also adjusted for smoking, number of non-occupational diseases and group 2 (hydrometallurgists). Smoking was independently associated with having an occupational disease claim in all groups (p < 0.001), as was the number of non-work-related diseases in six groups of seven. Despite consistent improvement in the exposure control measures in nickel production, occupational morbidity persists. More effort is needed to reduce exposure in final product cleaners.

Occupational disease predictors in the nickel pyrometallurgical production: a prospective cohort observation

“…When we consider risk factors of compensation claims in our analysis, cigarette smoking was confirmed as the strongest predictor of occupational claims in all occupational groups of our cohort, consistent with the effect in other occupational groups, including nickel electrolysis [ 10 ], gold mining [ 18 , 19 ], and most other occupations with male predominance and high smoking prevalence. Smoking ban in the workplace may be beneficial not only for smokers, but also for their non-smoking counterparts [ 19 ], likely due to discontinuation of exposure to environmental tobacco smoke in the workplace and in living premises in camps.…”

“…The company is one of the largest nickel producers in the world and sustains full nickel production cycle at various sites, including ore mining, ore dressing, pyrometallurgical processing and nickel refining by electrolysis and carbonyl methods. We earlier analyzed and described occupational claims of workers at another nickel production site of the same company, employed in the nickel electrolytic production [ 10 ]. Unlike electrolysis, usually considered the final stage of ready product production, pyrometallurgical ore processing stands midway between mining and final product.…”

“…The presentation of confirmed occupational disease and compensation claims in those exposed to nickel could be one of the ways to describe and understand the burden of nickel in occupationally exposed workers. We have earlier reported occupational disease compensation claims in nickel electrolysis workers from one of the world leading nickel final product producers, where we have identified a greater risk in the final product cleaners [ 10 ].…”

Occupational multimorbidity in the nickel industry workers

“…In addition, data on the quarterly departmental monitoring of air pollution in the industrial premises, including chemicals and fibrogenic aerosols are available. Working conditions attestation procedure in the Russian nickel industry along with the conventional grading of occupational hazards classes in the industry can be found in our previously published papers [ 18 , 26 ].…”

Copper Accumulation in the Lips of Brass Players: Case Report of a Rare Phenomenon

“…Work-related exposures affecting the oral cavity may be considered representative examples leading to such non-communicable diseases [ 5 ]. It is now well-known that teeth and the surrounding soft tissues may be affected by numerous physical, chemical, or mental occupational factors.…”