You may have read about a new study, published yesterday in the Archives of Pediatrics & Adolescent Medicine and now widely reported on, that documented a link between pregnant women's magnetic field exposure and their offspring's asthma risk in childhood. Scientists measured 801 expectant mothers' exposure to the low-frequency magnetic fields generated by power lines and by household appliances such as microwaves or hairdryers, and they observed that in children born to women with the highest magnetic field exposure, asthma risk was increased 3.5 times over low-exposure women in their first 13 years of life.
But some scientists not associated with the research are critical of the work, Reuters is reporting:
"The strong conclusions drawn from this paper that magnetic field exposure in pregnancy increases the risk of asthma in offspring cannot be justified based on the evidence provided in the publication," Patricia McKinney, professor of pediatric epidemiology at the University of Leeds in Britain, said in a statement.
McKinney said the study ignores major scientific reviews that concluded there was not a "sufficiently strong case for any further investigation of this topic."
The new study does have the advantage that it directly measured women's magnetic field exposures, unlike much of the prior research, which asked women to estimate their exposures. However, high-frequency electromagnetic fields such as those from cellphone and wireless networks were not measured, and asthma risk was not the study's primary outcome - it was originally designed to evaluate miscarriage risk. The results need to be replicated by other researchers in order to be definitive, the articles concludes.
