Dr. Weeks’ Comment: The data is damning. The news is being suppressed. Dr. Muskovitz from UC Berkley is worth listening to.
Occupational exposure to extremely low frequency magnetic fields and brain tumour risks in the INTEROCC study
Michelle C. Turner, Geza Benke, Joseph D. Bowman, Jordi Figuerola, Sarah Fleming, Martine Hours, Laurel Kincl,Daniel Krewski, Dave McLean, Marie-Elise Parent, Lesley Richardson, Siegal Sadetzki, Klaus Schlaefer, Brigitte Schlehofer, Joachim Schuz, Jack Siemiatycki, Martie Van Tongeren, and Elisabeth Cardis. Occupational exposure to extremely low frequency magnetic fields and brain tumour risks in the INTEROCC study. Cancer Epidemiology, Biomarkers, and Prevention. Published online first Jun 15, 2014.
Background: Occupational exposure to extremely low frequency magnetic fields (ELF) is a suspected risk factor for brain tumours, however the literature is inconsistent. Few studies have assessed whether ELF in different time windows of exposure may be associated with specific histologic types of brain tumours. This study examines the association between ELF and brain tumours in the large-scale INTEROCC study.
Methods: Cases of adult primary glioma and meningioma were recruited in seven countries (Australia, Canada, France, Germany, Israel, New Zealand, United Kingdom) between 2000 and 2004. Estimates of mean workday ELF exposure based on a job exposure matrix assigned. Estimates of cumulative exposure, average exposure, maximum exposure, and exposure duration were calculated for the lifetime, and 1-4, 5-9, and 10+ years prior to the diagnosis/reference date.
Results: There were 3,761 included brain tumour cases (1,939 glioma, 1,822 meningioma) and 5,404 population controls. There was no association between lifetime cumulative ELF exposure and glioma or meningioma risk. However, there were positive associations between cumulative ELF 1-4 years prior to the diagnosis/reference date and glioma (odds ratio (OR) ≥ 90th percentile vs < 25th percentile = 1.67, 95% confidence interval (CI) 1.36-2.07, p < 0.0001 linear trend), and, somewhat weaker associations with meningioma (OR ≥ 90th percentile vs < 25th percentile = 1.23, 95% CI 0.97-1.57, p = 0.02 linear trend).
Conclusions: Results showed positive associations between ELF in the recent past and glioma.
Although ELF exposure in the 1-4 year time window represents a small proportion of total lifetime occupational ELF exposure, these results are compatible with a role in tumour promotion. ELF cannot impart enough energy to DNA molecules to create mutations, however,it may act on signal transduction, cell proliferation, reactive oxygen species generation, the neuroendocrine or immune system, or interact with other chemical exposures (24, 25).
The positive association between ELF and glioma in the 1-4 year time window was seen for all exposure categories, including a large majority (~76%) of participants, across a wide spectrum of occupations, not solely “electrical occupations”.
In conclusion, in this large-scale study we observed no association with lifetime occupational ELF exposure. However, results from this, and several smaller previous studies showed positive associations between ELF in the more recent past and glioma, and probably with meningioma. Future work to better understand possible biological mechanims of action, interactions with other occupational exposures, associations with other occupational EMF exposures including
intermediate and RFs, and to consider interindividual variation in ELF exposure is needed.
Louis Slesin posted on his Microwave News web site today a review of the current study in context with earlier research on power-frequency magnetic fields
EMF Cancer Promotion: An Old Idea Makes a Strong Comeback
Large Study Shows Recent, But Not Lifetime, Exposures Lead to Brain Tumors
The new results, published online earlier this month by the journal Cancer Epidemiology, Biomarkers & Prevention, come from INTEROCC, an international project with seven participating countries designed to investigate occupational health risks from chemicals and EMFs. The project is directed by Elisabeth Cardis at CREAL in Barcelona with $1.5 million from the U.S. National Institutes of Health (though none of the tumor cases are from the U.S.) …