Bronchial carcinoma mortality in the German chromate-producing industry: the effects of process modification

Abstract

This study updates a 1982 report on mortality at two German chromate-producing factories. The main objective of the study was to establish whether the change-over to a production process using lime-free conversion of chromite ore, thus eliminating the formation of calcium chromate, had resulted in a distinct reduction in bronchial carcinoma mortality among workers exposed for the first time after the change-over (completed in 1958 in Leverkusen and 1964 in Uerdingen). A total of 1417 workers with at least 1 year of exposure were enrolled in the study. The observation period ended on 31 December 1988. The expected number of deaths was calculated using population statistics for North Rhine-Westphalia. The risk was determined in the form of a standardised mortality ratio (SMR), i.e. the ratio of observed deaths to expected deaths. In the group of 739 workers exposed before the process change-over was completed, 432 died during the observation period, 66 of them from bronchial carcinoma. This significant excess produced an SMR of 2.27 (95% confidence interval: 1.78-2.85). Where the cause of death was unknown, cases were allocated to a cause of death on the basis of the percentage occurrence of various causes of death in the specific subcohort. The cohort of 678 workers first exposed after the process modification had been completed had a slightly increased SMR for lung cancer of 1.26 (95% confidence interval: 0.58-2.38) based on nine cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose‐Response and Risk Assessment of Airborne Hexavalent Chromium and Lung Cancer Mortality

“…(24) Exposures to the different forms of Cr(VI) could not be differentiated, and it is possible that the risks observed in this analysis may be overestimated or underestimated for exposures to different forms of Cr(VI) if the carcinogenic potency varies by chemical species. Intrabrochial instillation data in animals (41,46) and epidemiological data (47,48) suggest that freely soluble forms of Cr(VI) may be less potent carcinogens than the sparingly soluble calcium chromate compounds typically formed in the high-lime production process. The data for the current Painesville cohort are consistent with this observation as workers who started in the 1960s, when less lime was being added to the roast mix, did not have an elevated lung cancer risk.…”

Occupational exposure to hexavalent chromium and cancers of the gastrointestinal tract: A meta-analysis

“…Results were comparable, however, when incidence data were used. Finally, both the Birk et al [19] and Korallus et al [20] studies were included, even though the more recent Birk study was a partial follow-up of the Korallus study, because these studies reported different GI cancers.…”

Lung Cancer Mortality in the German Chromate Industry, 1958 to 1998

“…6,9,13,14,21 Although the results were encouraging and suggested a reduction of lung cancer risk in postchange cohorts, they were not conclusive because none fully allowed for the typical latency period of 20 to 25 years. These studies were limited further by relatively small cohorts, the absence of quantitative exposure data, and the absence of data on confounding factors, such as smoking.…”

“…1,2,6,10,13,14 Although these studies suggested a reduction in risk, the findings have been considered inconclusive because of methodological issues, including small cohort size, absence of smoking data, and an insufficient latency period. 2,6,9,14,21 Three studies that quantified exposure levels among chromate workers also provide some evidence of lower risks of lung cancer among post-change workers but have similar methodological limitations. [22][23][24] We conducted a large multiplant study in the United States and Germany to examine the mortality experience of postchange employees.…”

“…The study evaluated individual exposure to Cr (VI) using chromium levels in urine as a biomarker of exposure to Cr (VI). The cohort reported here updates mortality for many employees who were studied previously, 14,21,26 excluding employees present before conversion to the no-lime production process was completed and adding new cohort members. Analysis of lung cancer risk by cumulative Cr, as measured in urine, and controlling for smoking are presented here and were not part of previous studies overlapping with this cohort.…”