Although little evidence was found for other neurodegenerative diseases including dementia and multiple sclerosis, few studies had been conducted on these diseases.
The paper concludes, “We observed moderate associations between indicators of occupational MF exposure … and AD,” but the Abstract states, “We found weak associations for occupational MF exposure proxies with AD.”
Despite statistically significant findings, the authors argued that, “Our results do not support MF as the explanation for observed associations ... Because the associations we observed indicate potential risks but are far from decisive, we suggest that improved studies are needed.”
That this paper downplayed the risks of MF exposure is not surprising because the study was sponsored by the Electric Power Research Institute (EPRI), a nonprofit organization funded by the electrical utility industry. The paper’s first author, Ximena Vergara, is an EPRI employee, and the other authors are academics whose research has been supported by EPRI.
But even if there had been no conflicts of interest, scientists rarely assert they have conclusive evidence. In fact, such assertions are generally antithetical to scientific inquiry, which is typically a never-ending process that calls for more research.
Because policy makers generally desire conclusive evidence before taking action, major delays typically occur before people are protected from emerging health risks like tobacco or asbestos, especially when diseases occur only after prolonged exposure as in the case of neurodegenerative disease or cancer.
In 2001, a group of experts convened by the World Health Organization reviewed the research on magnetic fields, and determined it “possibly carcinogenic to humans (Group 2B).” Now, almost twelve years later, a group of researchers comes to a similar conclusion with regard to certain neurodegenerative diseases.
Most of the studies reviewed were conducted in the U.S. and Nordic countries. For ALS, the association with MF exposure was stronger in studies based upon the job title (e.g., electrical technician). Overall, these studies found 43% increased risk of ALS. For AD, the association with MF was stronger in studies that directly measured MF exposure. Overall, these studies found 58% increased risk for AD.
Many nations, especially in Europe, and at least one city in the U.S. (San Francisco) follow the precautionary principle. This principle, developed at a U.N. environmental conference in 1992, states that in the absence of scientific consensus if an action has a suspected risk of causing harm, the burden of proof it is not harmful falls on those taking the action, and all reasonable measures to reduce the risk must be taken.
The precautionary principle does not require us to abandon technologies that emit magnetic fields (e.g., electricity)
We need to develop and support scientific communities that are completely independent of industry to develop safer technologies and find safer ways to employ current technologies. Moreover, we need policy makers with the courage to stand up to industry and adopt precautionary safety regulations that protect the health of workers and the public, not just the health of industries.
The review paper was published in the February issue of the Journal of Occupational and Environmental Medicine.
Consumer Safety from magnetic fields
Some utility companies claim they follow a precautionary approach. PG&E, for example, states that it follows the precautionary guidelines recommended by the Swedish government: “If measures to reduce exposure can be taken at reasonable expense and with reasonable consequences in all other aspects, an effort should be made to reduce fields radically deviating from what could be deemed normal in the environment.”
PG&E periodically informs its customers about devices with strong magnetic fields (e.g., hair dryers, electric ranges, and microwave ovens) in a fact sheet that contains tips about how to reduce exposure:
“ ... you can increase your distance from electric appliances and/or limit the amount of time you use appliances at home or at work.”
“... you can place phone answering machines and electric clocks away from the head of your bed. Increasing your distance from these and other appliances such as televisions, computer monitors and microwave ovens can reduce your EMF exposure.”
“... limiting the time you spend using personal appliances such as hair dryers, electric razors, heating pads and electric blankets. You may also want to limit the time you spend using electric cooking appliances.”
Unfortunately, few consumers are likely to read this fact sheet as it is one of several inserts stuffed into an envelope with a utility bill. Moreover, it contains numerous caveats which are likely to undermine potential compliance. For example:
“Given the uncertainty of the issue, the medical and scientific communities have been unable to conclude that usual residential exposures to EMF cause health effects, or to establish any standard or level of residential exposure that is known to be either safe or harmful.”
Vergara, X et al. Occupational Exposure to Extremely Low-Frequency Magnetic Fields and Neurodegenerative Disease: A Meta-Analysis. (http://ovidsp.tx.ovid.com/
Zhou, H et al. (2012) Association between Extremely Low-Frequency Electromagnetic Fields Occupations and Amyotrophic Lateral Sclerosis: A Meta-Analysis. PLoS ONE 7(11): e48354.http://
García, A et al. Int J Epidemiol. 2008 Apr;37(2):329-
Juutilainen J. Do electromagnetic fields enhance the effects of environmental carcinogens?