A mortality study of cobalt production workers: An extension of the follow‐up

Abstract

The follow-up of a cohort of workers employed in an electrochemical plant producing cobalt and sodium, previously studied from 1950-1980, has been extended from 1981-1988. The standardized mortality ratio (SMR) for all causes of death was 0.85 (95% confidence interval [CI] = 0.76-0.95, 309 observed) for the whole cohort, and 0.95 (95% CI = 0.83-1.08, 247 observed) for the subcohort of workers born in France. With regard to lung cancer mortality among cobalt production workers, which is the main objective of the study, the SMRs were, respectively, 0.85 (95% CI = 0.18-2.50, 3 observed) and 1.16 (95% CI = 0.24-3.40, 3 observed). Neither did any excess of mortality from diseases of the circulatory and of the respiratory systems appear among cobalt production workers. Maintenance workers, however, exhibited high SMRs for lung cancer, reaching statistical significance for duration of exposure and time since first exposure > or 30 years. This study does not support the hypothesis of a relationship between lung cancer and cobalt exposure.

Absence of significant genotoxicity in lymphocytes and urine from workers exposed to moderate levels of cobalt-containing dust: A cross-sectional study

“…In an electrochemical plant where workers were exposed to cobalt alone, no increased risk of lung cancer could be detected after a follow-up period of more than 35 years (1950 -1988; standardized mortality ratio [SMR], 0.85) [Moulin et al, 1993]. In contrast, a mortality study in workers from the hard metal industry followed from 1956 to 1989 showed a significantly increased mortality from lung cancer (SMR, 2.13) that was related to the intensity of exposure (SMR, 5.03 in the highest exposure group).…”

Characterization of exposures among cemented tungsten carbide workers. Part I: Size-fractionated exposures to airborne cobalt and tungsten particles

“…Cases of HMD have been reported among workers in all phases of CTC production (Bech et al, 1962;Coates and Watson, 1971;Sjo¨gren et al, 1980;Davison et al, 1983;Sprince et al, 1984Sprince et al, , 1988Meyer-Bisch et al, 1989;Cugell et al, 1990;Figueroa et al, 1992;Fischbein et al, 1992), which may be due to exposures to tungsten carbide particles in association with cobalt particles (Lasfargues et al, 1992(Lasfargues et al, , 1995Lison and Lauwerys, 1990, 1994, 1995Lison et al, , 1996. In humans, excess lung cancer has been observed among hard metal workers exposed to CTC dusts (Lasfargues et al, 1994;Moulin et al, 1998;Wild et al, 2000;Lison et al, 2001), but not among cobalt production workers exposed to cobalt alone (Moulin et al, 1993). In vitro and in vivo studies indicate that the genotoxicty of cobalt in the presence of tungsten carbide is greater than either component alone (Anard et al, 1997;Van Goethem et al, 1997;Lison et al, 2001;De Boeck et al, 2003a, b;Mateuca et al, 2005).…”

Introduction: Epidemiologic research and prevention of occupational cancer in Europe.

“…With the rise of modern epidemiology in the 1950s, several important industry-based studies were conducted in the United Kingdom during the 1950s and the 1960s. (12) and cobalt (13).…”