Case-control study on occupational exposure to extremely low-frequency electromagnetic fields and glioma risk

Case-control study on occupational exposure to extremely low-frequency electromagnetic fields and glioma risk
Exposure to extremely low-frequency electromagnetic fields (ELF-EMF) was in 2002 classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO.
Life time occupations were assessed in case-control studies during 1997-2003 and 2007-2009. An ELF-EMF Job-Exposure Matrix was used for associating occupations with ELF exposure (μT). Cumulative exposure (μT-years), average exposure (μT), and maximum exposed job (μT) were calculated.
Cumulative exposure gave for astrocytoma grade IV (glioblastoma multiforme) in the time window 1-14 years odds ratio (OR) = 1.9, 95% confidence interval (CI) = 1.4-2.6, p linear trend <0.001, and in the time window 15+ years OR = 0.9, 95%CI = 0.6-1.3, p linear trend = 0.44 in the highest exposure categories 2.75+ and 6.59+ μT years, respectively. Conclusion
An increased risk in late stage (promotion/progression) of astrocytoma grade IV for occupational ELF-EMF exposure was found.

Also see: EMF Cancer Promotion: An Old Idea Makes a Strong Comeback Excerpt,for full article
Large Study Shows Recent, But Not Lifetime, Exposures Lead to Brain Tumors.

Power-frequency magnetic fields can promote brain tumors, according to the largest epidemiological study of its kind ever undertaken.Results published online 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 INTEROCC team found that those who were exposed to elevated EMF exposures at work during the five years prior to diagnosis had significantly higher rates of glioma compared to those who were least exposed during that time on the job.2 The greater the exposure, the greater the tumor risk. Those who were most highly exposed had approximately 67% more tumors. The key concept here is cancer promotion, as opposed to cancer causation or initiation.

The INTEROCC results point to EMFs as a promoter, and not as an initiator. The EMFs do not cause cancer, rather they foster its growth and development. The new finding will help sidestep the most often cited objection to the idea that magnetic fields are linked to cancer because no EMF–induced DNA breaks would be required.

Also see: Occupational exposure and amyotrophic lateral sclerosis in a prospective cohort These results strengthen the evidence suggesting a positive association between ELF-MF exposure and ALS.

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