Occupational exposure to extremely low frequency magnetic fields and brain tumour risks in the INTEROCC study

Authored By:

Turner MC, Benke G, Bowman JD, Figuerola J, Fleming S, Hours M, Kincl L, Krewski D, McLean D, Parent ME, Richardson L, Sadetzki S, Schlaefer K, Schlehofer B, Schuz J, Siemiatycki J, van Tongeren M, Cardis E

Summary:

This is a case-control study investigating whether occupational exposure to extremely low frequency (ELF) magnetic fields is associated with brain tumours. In the study the occupational exposure to ELF magnetic fields was compared between 3,761 cases of brain tumour (1,939 glioma, 1,822 meningioma) diagnosed between 2000‑2004 and 5,404 controls. Exposure to ELF magnetic fields was assessed using a job-exposure matrix (JEM). There was no association between lifetime cumulative ELF exposure and glioma or meningioma. However, there was a positive association between cumulative exposure to ELF magnetic fields 1‑4 years prior to the diagnosis date and glioma (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.36-2.07). The authors conclude that the results showed a positive association between occupational exposure to ELF magnetic fields in the recent past and glioma.

Link to:

Link to PubMed abstract

Published In:

Cancer Epidemiol Biomarkers Prev 2014: in press

Commentary by ARPANSA:

In 2002, the International Agency for Research on Cancer (IARC) classified ELF magnetic fields as “possibly carcinogenic to humans” (http://monographs.iarc.fr/ENG/Monographs/vol80/volume80.pdf). The classification was based on “limited” epidemiological evidence for an association between prolonged exposure to higher than normal residential ELF magnetic fields and childhood leukaemia. However, this association is not supported by laboratory or animal studies and no credible theoretical mechanism has been proposed.

Subsequent to the IARC classification a number of epidemiological studies have investigated whether occupational exposure to ELF magnetic fields is associated with adult cancers and in particular breast cancer, leukaemia and brain tumours. Results from these studies have been largely inconsistent. In 2007 the World Health Organization assessed the evidence and found that overall the evidence for an association between occupational exposure to ELF magnetic fields and cancer remains inadequate
(www.who.int/peh-emf/publications/Complet_DEC_2007.pdf).