Occupational exposure to power frequency magnetic fields and risk of non-Hodgkin lymphoma
- K Karipidis1,
- G Benke1,
- M Sim1,
- L Fritschi2,
- M Yost3,
- B Armstrong4,
- A M Hughes5,
- A Grulich6,
- C M Vajdic6,
- J Kaldor6,
- A Kricker4
- 1Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- 2Western Australian Institute for Medical Research, Perth, Western Australia, Australia
- 3Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, USA
- 4School of Public Health, University of Sydney, Sydney, NSW, Australia
- 5Department of Health Sciences, University of York, Heslington, York, UK
- 6National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, New South Wales, Australia
- Correspondence to: MrK Karipidis 619 Lower Plenty Road, Yallambie, VIC 3085, Australia; ken.karipidis{at}arpansa.gov.au
- Accepted 16 March 2006
- Published Online First 21 March 2006
Abstract
Objectives: To investigate the risk of non-Hodgkin lymphoma (NHL) using a job-exposure matrix (JEM) to assess exposure to occupational magnetic fields at the power frequencies of 50/60 Hz.
Methods: The study population consisted of 694 cases of NHL, first diagnosed between 1 January 2000 and 31 August 2001, and 694 controls from two regions in Australia, matched by age, sex and region of residence. A detailed occupational history was given by each subject. Exposure to power frequency magnetic fields was estimated using a population-based JEM which was specifically developed in the United States to assess occupational magnetic field exposure. The cumulative exposure distribution was divided into quartiles and adjusted odds ratios were calculated using the lowest quartile as the referent group.
Results: For the total work history, the odds ratio (OR) for workers in the upper quartile of exposure was 1.48 (95% CI 1.02 to 2.16) compared to the referent (p value for trend was 0.006). When the exposure was lagged by 5 years the OR was 1.59 (95% CI 1.07 to 2.36) (p value for trend was 0.003). Adjusting for other occupational exposures did not significantly alter the results.
Conclusions: These findings provide weak support for the hypothesis that occupational exposure to 50/60 Hz magnetic fields increases the risk of NHL.
Footnotes
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Published Online First 21 March 2006
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Funding: The study was funded by the National Health and Medical Research Council (NHMRC) of Australia, the Cancer Council NSW and the University of Sydney Medical Foundation. Lin Fritschi is supported by a NHMRC Career Development Award. Claire Vajdic has a Post-doctoral Research Fellowship of the NHMRC. Ann Maree Hughes was a University of Sydney Faculty of Medicine Postgraduate Scholarship recipient. Bruce Armstrong’s research is supported by a University of Sydney Medical Foundation program grant. The National Centre in HIV Epidemiology and Clinical Research is funded by the Australian Government Department of Health and Ageing.
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Competing interests: None.
