Study type: Epidemiological study (observational study)

Cancer incidence in UK electricity generation and transmission workers, 1973-2008. epidem.

Published in: Occup Med (Lond) 2012; 62 (7): 496-505

Aim of study (acc. to author)

A cohort study was conducted in the UK to investigate the effects of magnetic field exposure on cancer risks among a cohort of electricity generation and transmission workers .

Further details

Cancer incidence in the worker cohort was compared with expected values based on incidence rates for the general population of England and Wales, taking sex, age and calendar period into account.

Endpoint/type of risk estimation

Type of risk estimation: (standardized incidence rate (SIR))

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 general population of England and Wales
Group 2 cohort of UK electricity generation and transmission workers

Population

Study size

Type Value
Total 83,923
Evaluable 81,842

Conclusion (acc. to author)

Overall, cancer morbidity was slightly below expectation in males and females. Significant excesses were found in male workers for mesothelioma (a well known risk factor for mesothelioma is asbestos), skin cancer (non-melanoma) as well as prostate cancer and in female workers for cancer of the small intestine and nasal cancer. Brain cancers were close to expectation in males and below expectation in females. Leukemia incidence (all types) was slightly below expectation in males and females.
More detailed analyses including year of hire, period from first employment, period from leaving employment, industry sector and type of work showed important contrasts for mesothelioma and leukemia. The clear occupational excess of mesothelioma was not matched by a corresponding excess of lung cancer (a ratio of 2:1 for excess lung cancers/mesothelioma caused by asbestos is often observed), and the level of asbestos-induced lung cancer in this industry must be low. Leukemia risks declined with period from hire; confident interpretation of this finding is not possible. The excesses of cancers of the nasal cavities and small intestine are probably not occupational, though the excess of skin cancer may be due to outdoor work.

Study funded by

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