Magnetic field (MF) non-ionizing radiation is widespread and everyone is exposed to some degree. This prospective cohort study of 913 pregnant women examined the association between high MF exposure and miscarriage risk. Cox (proportional hazards) regression was used to examine the association. After controlling for multiple other factors, women who were exposed to higher MF levels had 2.72 times the risk of miscarriage (hazard ratio = 2.72, 95% CI: 1.42–5.19) than those with lower MF exposure. The increased risk of miscarriage associated with high MF was consistently observed regardless of the sources of high MF. The association was much stronger if MF was measured on a typical day of participants’ pregnancies. The finding also demonstrated that accurate measurement of MF exposure is vital for examining MF health effects. This study provides fresh evidence, directly from a human population, that MF non-ionizing radiation could have adverse biological impacts on human health.
In this study, we found an almost three-fold increased risk of miscarriage if a pregnant woman was exposed to higher MF levels compared to women with lower MF exposure. The association was independent of any specific MF exposure sources or locations, thus removing the concern that other factors connected to the sources of the exposure might account for the observed associations. While nausea and vomiting were hypothesized to be potential confounders, adjustment for both nausea and vomiting did not change the results in this study or in a previous study20. Although we did not observe a dose-response relationship for MF exposure above 2.5 mG, this could be due to a threshold effect of MF exposure in which MF levels at or above 2.5 mG could lead to fetal demise, thus examining further higher levels of MF exposure were not able to confer additional risk.
Given the ubiquitous nature of exposure to this non-ionizing radiation, a small increased risk due to MF exposure could lead to unacceptable health consequences to pregnant women. Although the number of epidemiological studies examining the adverse impact of MF exposure in humans remains limited, the findings of this study should bring attention to this potentially important environmental hazard to pregnant women, at least in the context of miscarriage risk, and stimulate much needed additional research.
The study (in our opinion) is misleading in that it mentions high frequency magnetic fields and radiofrequency devices when it should be more specific in that the magnetic field cannot be measured separately from the electric fields at those higher frequencies.
Furthermore if we are reading it correctly, this study in fact has severe limitations and could only be conducted with reference to pregnancies that were subjected to magnetic fields up to 1000Hz because according to the specifications of the meter, that is the upper frequency limit of the magnetic field meter that was used.
For instance if any of the mothers used an induction hotplate which would be emitting in the region of 30 000 -50 000Hz the meter would have only picked up radiation from the 50Hz current flow within the stove supplying the hotplate. Similarly if a mother would have stood within 1 metre of a functioning microwave oven the meter would have registered the high 50/60Hz magnetic field generated by the transformer that drives the magnetron to produce the e.m. energy but not the 2.4GHz microwave energy leaking through the oven door!
So while these lower frequency magnetic fields may be more penetrating and therefore be comparatively more biologically active [maybe!] no account is given of biological reactions that may have been caused by any other radiation exposure above the 1000Hz of which there is veritable soup of frequencies.
In our opinion there might have been a little more credibility if R.F blocking material had been worn by the mothers in the way of an undergarment or apron. It is a known fact that these materials cannot block low frequency magnetic fields up to 1000Hz.
1000Hz (which we feel we must repeat) – is the upper limit of the meter used.
EMFs and Miscarriages: http://microwavenews.com/news-center/de-kun-li-miscarriages