| Autor: |
Korallus, U., Ulm, K., Steinmann-Steiner-Haldenstaett, W. |
| Zdroj: |
International Archives of Occupational & Environmental Health; 1993, Vol. 65 Issue 3, p171-178, 8p |
| Abstrakt: |
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. The SMR was considerably lower than in the pre change cohort, indicating the probable success of the process modification. The different age distributions in both cohorts were adjusted by analysis according to latency period. In the pre-change cohort the SMRs were 1.90 (≤ 10 years), 2.93 (11-20 years) and 2.14 (> 20 years). The corresponding values in the post-change cohort were 1.32, 1.32 and 0.91 (the last figure based on only one case). The SMR of 1.26 in the post-change cohort has to be seen in the light of a number of factors: smoking is more common in industrial cohorts than in the general population; the cause of death was ascertained using the best available information; there was additional exposure to asbestos; the latency period was short; and the SMR decreased with increasing latency period. There was no significant excess of deaths from nasal cancer. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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