Occupational Medicine 2004;54:28-34
© Society of Occupational Medicine 2004; all rights reserved
Mortality of Workers at a Plant Manufacturing Nickel Alloys, 1958–2000
Institute of Occupational Health, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
Background Excess risks of respiratory cancer have been demonstrated in some groups of nickel-exposed workers. It is clear, however, that not all forms of nickel exposure are implicated in these excess risks.
Aim To determine whether occupational exposures received in the manufacture of nickel alloys lead to increased risks of cancer, in particular nasal cancer and lung cancer.
Methods The mortality experienced by a cohort of 1999 workers employed at a plant manufacturing nickel alloys has been investigated. Study subjects were all those male workforce employees first employed in the period 1953–1992 who had at least 5 years employment with the company. Observed numbers of cause-specific deaths were compared with expectations based on national mortality rates. Standardized mortality ratios (SMRs) were calculated by period from commencing employment and by operating area of first job. In addition, rate ratios derived from Poisson regression and based on an internal standard were calculated by levels of duration of employment.
Results SMRs were significantly below 100 for all causes (observed 557, expected 704.3, SMR 79), all neoplasms (observed 169, expected 209.4, SMR 81) non-malignant diseases of the respiratory system (observed 50, expected 73.0, SMR 69) and diseases of the circulatory system (observed 261, expected 335.5, SMR 78). Significantly elevated SMRs were not shown for any cause of death and mortality was below expectation for stomach cancer (observed 8, expected 16.0, SMR 50), lung cancer (observed 64, expected 73.6, SMR 87) and bladder cancer (observed 3, expected 8.0, SMR 38). There were no deaths from nasal cancer (expected 0.33). More detailed findings were unexceptional.
Conclusions The analyses did not suggest the presence of an occupational cancer hazard in the mortality experience of the cohort.
Keywords Cancer mortality; nickel alloys
Received 19 May 2003
Revised 28 July 2003
Accepted 8 August 2003
Correspondence to: Professor T. Sorahan, Institute of Occupational Health, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. Tel: +44 121 414 3644; fax: +44 121 414 2613; e-mail: t.m.sorahan{at}bham.ac.uk.