Lung cancer risk associated with occupational exposure to nickel, chromium VI, and cadmium in two population-based case-control studies in Montreal (original) (raw)
Related papers
International Journal of Cancer
There is limited evidence regarding the exposure‐effect relationship between lung‐cancer risk and hexavalent chromium (Cr(VI)) or nickel. We estimated lung‐cancer risks in relation to quantitative indices of occupational exposure to Cr(VI) and nickel and their interaction with smoking habits. We pooled 14 case‐control studies from Europe and Canada, including 16 901 lung‐cancer cases and 20 965 control subjects. A measurement‐based job‐exposure‐matrix estimated job‐year‐region specific exposure levels to Cr(VI) and nickel, which were linked to the subjects' occupational histories. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated by unconditional logistic regression, adjusting for study, age group, smoking habits and exposure to other occupational lung carcinogens. Due to their high correlation, we refrained from mutually adjusting for Cr(VI) and nickel independently. In men, ORs for the highest quartile of cumulative exposure to CR(VI) were 1.32 (95%...
Determinants of lung cancer risk among cadmium-exposed workers
Annals of Epidemiology, 1992
Workers at a cadmium recovery pIant in Globe, Colorado, showed an increased risk of lung cancer, which some investigators have attributed to cadmium exposure. We conducted a cohort mortality analysis of this work force and a case-control analysis of the lung cancer cases within this work force in order to assess the probable causes of the lung cancer excess. The Globe plant began as a lead smelter about 1886, switched to arsenic production in 1920, and became a cadmium metal production facility in 1926. Cadmium, arsenic, and cigarette smoking are three potential lung carcinogens found in this workplace. Industrial hygiene data collected from I943 onward served as the basis for the National Institute for Occupational Safety and Health (NIOSH)-derived exposure algorithm that assigned cadmium exposure estimates to employees based on their work area in the plant and calendar time. Few exposure data existed for substunces other than cadmium. Feedstock ore concentrations were used us a surrogate measure of air arsenic levels. The arsenic content of the fines used as feedstock prior to I940 was considerably higher than rhat of the fines used after 1940. Smoking histories had been obtained previously for 45% of the workers. A case-control analysis of the 25 cases of lung cancer known to have occurred among these workers through 1982 was conducted using three controls per case, matched by closest data of hire and age at hire. Porenrial causal agents for lung cancer included cadmium exposure, cigarette smoking, and arsenic exposure. Exposure variables for each case and control included estimated cumulative cadmium exposure in milligram-years per cubic meter, cigarette smoking history, and plant arsenic exposure status at the time of hire. Estimated cumuhtiwe cadmium exposures of cases and controls did not differ overall or within the date-of-hire strata. Cases were more than eight rimes more likely to have been cigarette smokers than were controls. Lung cancer risk in this workplace was more closely related to the period of hire, not to the cumulative cadmium eqosure. The period of hire appears to be a surrogate for arsenic exposure as related to feedstock. The measures used here seem to indicate that exposure to arsenic and cigarette particulates, rather than to cadmium particulates, may have caused the increased rate of lung cancer of these workers. Ann Epidemiol I992;2; 195-2 11.
Cancer mortality of cadmium workers
Occupational and Environmental Medicine, 1985
Several epidemiological studies of workers exposed to cadmium indicate an increased risk of lung and prostatic cancer. The increase is statistically significant in some of the studies but the SMR is greater than 100 in almost all. A cohort study of the mortality among 522 Swedish workers exposed to cadmium for at least one year in a nickel-cadmium battery plant support the earlier findings. The SMR for lung and prostatic cancer increased with increasing dose and latency but did not obtain statistical significance. A combination of all the available data from the most recent follow up of causes of death among cadmium workers in six different cohorts shows 28 cases of prostatic cancer (SMR = 162) and 195 cases of lung cancer (SMR = 121). This new analysis suggests that long term, high level exposure to cadmium is associated with an increased risk of cancer. The role of concomitant exposure to nickel needs further study.
Exposure to Welding Fumes, Hexavalent Chromium, or Nickel and Risk of Lung Cancer
American Journal of Epidemiology, 2019
To investigate the risk of lung cancer after exposure to welding fumes, hexavalent chromium (Cr(VI)), and nickel, we analyzed 3,418 lung cancer cases and 3,488 controls among men from 2 German case-control studies (1988-1996). We developed a welding-process exposure matrix from measurements of these agents, and this was linked with welding histories from a job-specific questionnaire to calculate cumulative exposure variables. Logistic regression models were fitted to estimate odds ratios with confidence intervals conditional on study, and they adjusted for age, smoking, and working in other at-risk occupations. Additionally, we mutually adjusted for the other exposure variables under study. Overall, 800 cases and 645 controls ever worked as regular or occasional welders. Odds ratios for lung cancer with high exposure were 1.55 (95% confidence interval (CI): 1.17, 2.05; median, 1.8 mg/m 3 × years) for welding fumes, 1.85 (95% CI: 1.35, 2.54; median, 1.4 μg/m 3 × years) for Cr(VI), and 1.60 (95% CI: 1.21, 2.12; median, 9 μg/m 3 × years) for nickel. Risk estimates increased with increasing cumulative exposure to welding fumes and with increasing exposure duration for Cr(VI) and nickel. Our results showed that welding fumes, Cr(VI), and nickel might contribute independently to the excess lung cancer risk associated with welding. However, quantitative exposure assessment remains challenging.
Lung cancer among workers in chromium chemical production
American Journal of Industrial Medicine, 2000
Background An elevated risk of lung cancer among workers in chromate production facilities has previously been reported. This excess risk is believed to be the result of exposure to hexavalent chromium. There have been mixed reports about whether trivalent chromium exposure is also associated with an excess lung cancer risk. Previous studies of measured hexavalent chromium exposure and lung cancer risk have not examined cigarette smoking as a risk factor. Methods A cohort of 2,357 workers ®rst employed between 1950 and 1974 at a chromate production plant was identi®ed. Vital status of the workers was followed until December 31, 1992. Work histories of cohort members were compiled from the beginning of employment through 1985, the year the plant closed. Annual average exposure estimates, based on historical exposure measurements, were made for each job title in the plant for the years 1950±1985. These exposure estimates were used to calculate the cumulative hexavalent chromium exposure of each member of the study population. Following closure of the plant, settled dust samples were collected and analyzed for hexavalent and trivalent chromium. The trivalent/hexavalent concentration ratios in each plant area were combined with historic air-sampling data to estimate cumulative trivalent chromium exposure for each individual in the study cohort. Smoking status (yes/ no) as of the beginning of employment and clinical signs of potential chromium irritation were identi®ed from company records. Results Cumulative hexavalent chromium exposure showed a strong dose±response relationship for lung cancer. Clinical signs of irritation, cumulative trivalent chromium exposure, and duration of work were not found to be associated with a risk of lung cancer when included in a proportional hazards model with cumulative hexavalent chromium exposure and smoking. Age-speci®c data on cumulative hexavalent chromium exposure, observed and expected numbers of lung cancer cases, and person-years of observation are provided. Conclusion Cumulative hexavalent chromium exposure was associated with an increased lung cancer risk; cumulative trivalent chromium exposure was not. The excess risk of lung cancer associated with cumulative hexavalent chromium exposure was not confounded by smoking status. The current study offers the best quantitative evidence
Regulatory Toxicology and Pharmacology, 2003
Increased lung and nasal cancer risks have been reported in several cohorts of nickel refinery workers, but in more than 90% of the nickel-exposed workers that have been studied there is little, if any evidence of excess risk. This investigation utilizes human exposure measurements, animal data from cancer bioassays of three nickel compounds, and a mechanistic theory of nickel carcinogenesis to reconcile the disparities in lung cancer risk among nickel-exposed workers. Animal data and mechanistic theory suggest that the apparent absence of risk in workers with low nickel exposures is due to threshold-like responses in lung tumor incidence (oxidic nickel), tumor promotion (soluble nickel), and genetic damage (sulfidic nickel). When animal-based lung cancer dose-response functions for these compounds are extrapolated to humans, taking into account interspecies differences in deposition and clearance, differences in particle size distributions, and human work activity patterns, the predicted risks at occupational exposures are remarkably similar to those observed in nickel-exposed workers. This provides support for using the animal-based dose-response functions to estimate occupational exposure limits, which are found to be comparable to those in current use.
American Journal of Industrial Medicine, 2020
Background: Hexavalent chromium has been found to increase the risk of lung cancer in occupational studies. It has been suggested that the relative risk of lung cancer may vary by age. Methods: The cohort examined is the Baltimore cohort of chromium production workers. The effect of age on the lung cancer risk from hexavalent chromium exposure was examined using a conditional Poisson regression modeling approach of Richardson and Langholz (R&L) and Cox models with interaction terms of age and cumulative hexavalent chromium exposure. Results: The inclusion of multiple age groups in the R&L approach suggests the existence of an age effect that is also supported by a Cox proportional hazard analysis. The hazard ratio in Cox models with age-cumulative exposure interaction terms was significantly elevated for the youngest age group and significantly decreased for the oldest age group. Conclusions: Our analyses are consistent with the observation that younger chromium production workers have a greater lung cancer risk than older workers.
Lung Cancer Risk in Hard-Metal Workers
American Journal of Epidemiology, 1998
An industry-wide mortality study on the association between lung cancer and occupational exposure to cobalt and tungsten carbide was carried out in the French hard-meta) industry. This case-control study was nested in the historical cohort of workers ever employed in this Industry's 10 facilities, most of which are located in eastern France. Workers were followed up from 1968 to 1991. Occupational exposure was assessed using a job-exposure matrix that provided semiquantitative scores for 320 job periods. These scores were significantly correlated with the levels of cobalt measured in 744 historical air samples. In this cohort, which comprised 5,777 males and 1,682 females, the death rate from lung cancer was significant (63 deaths, standardized mortality ratio = 1.30, 95% confidence interval (Cl) 1.00-1.66) when compared with national death rates. Sixty-one cases and 180 controls were included In the study. When the exposures during the last 10 years were ignored, a twofold lung cancer risk was observed among workers simultaneously exposed to cobalt and tungsten carbide (odds ratio (OR) = 1.93, 95% Cl 1.03-3.62) adjusted for other cobalt exposure (OR = 2.21, 95% Cl 0.99-4.90). The odds ratios increased with cumulative exposure (first quartile, OR = 1.00; second quartile, OR = 2.64; third quartile, OR = 2.59; fourth quartile, OR = 4.13) and, to a lesser degree, with duration of exposure (one decade, OR = 1.00; two decades, OR =1.61; three decades, OR = 2.77; four decades, OR = 2.03). Adjustments for smoking and for exposures to known or suspected carcinogens did not change the results, yet the odds ratio for smoking (3.38) was lower than expected, suggesting the possibility of some misclassification. Occupational risk was highest among smokers. This study supports the hypothesis that workers who manufacture hard metals have an increased mortality from lung cancer due to simultaneous exposure to cobalt and tungsten carbide. Am J Epidemiol 1998; 148:241-8.