Mortality study of chemical workers exposed to dioxins: follow-up 23 years after chemical plant closure
- 1Institute for Occupational and Maritime Medicine, Hamburg, Germany
- 2Department of Occupational Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- 3Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- 4Centre for Chemical Workers' Health, Department of Health, Hamburg, Germany
- Correspondence to Ulf Manuwald, Institute for Occupational and Maritime Medicine, Seewartenstraße 10, 20459, Hamburg;
Contributors AM and XB conceived the idea. UM performed the calculations and assisted in the analysis. UM, MVG and XB wrote the first draft of the paper. All authors critically analysed results, interpreted the data, read, critically revised and approved the manuscript.
- Accepted 27 May 2012
- Published Online First 5 July 2012
Objectives To examine the long-term effects of dioxin-exposure, particularly with regard to cancer mortality, in a follow-up 23 years after closure of the chemical plant (Hamburg, Germany).
Methods The study comprised all persons (1191 men/398 women) employed in the plant on a full-time basis for a minimum of 3 months between 1952 and 1984 when the plant was closed down. Mortality follow-up was performed for the period from 1952 up to the reference date of 31 December 2007. Subjects entered the cohort at the date of their first employment in the plant. We calculated standardised mortality ratios (SMRs) using the population of Hamburg as reference.
Results The vital status could be determined for 96.5% of the study group (1145 men and 389 women). For men, there was an increase in overall mortality (ICD-9 1–999) (SMR=1.14, 95% CI 1.06 to 1.23), all-cancer mortality (SMR=1.37, 95% CI 1.21 to 1.56) and specific mortality from respiratory cancer (ICD-9 161, 162, 163) (SMR=1.64, 95% CI 1.32 to 2.03), oesophageal cancer (ICD-9 150) (SMR=2.56, 95% CI 1.27 to 4.57), rectum cancer (ICD-9 154) (SMR=1.96, 95% CI 0.98 to 3.51), as well as diseases of the circulatory system (ICD-9 390–459) (SMR=1.16, 95% CI 1.02 to 1.31). For women, there was an increase in breast cancer mortality (ICD-9 174) (SMR=1.86, 95% CI 1.12 to 2.91).
Conclusions The results of this extended follow-up are consistent with those of previous analyses of the cohort and with those of other cohorts. Our findings support the carcinogenic effect of dioxin compounds.
Funding This study was funded by a grant from the German Federal Ministry of Labour and Social Affairs.
Competing interests None.
Ethics approval The study was conducted with the approval of the medical ethics committee of the Hamburg Medical Association.
Provenance and peer review Not commissioned; externally peer reviewed.