Non-ionizing radiation from magnetic fields occurs when electrical devices are used and electricity flows.
Exposure to non-ionizing radiation from smartphones, wi-fi routers and microwaves during pregnancy can significantly increase the risk of miscarriage, warns a study.
Non-ionizing radiation from magnetic fields occurs when electrical devices are in use and electricity is flowing.
Can be generated by a number of environmental sources, including electrical appliances, power lines and transformers, wireless devices and wireless networks.
Humans are exposed to magnetic fields near these sources while they are in use.
While the health hazards of ionizing radiation are well established and include radiation sickness, cancer and genetic damage, evidence of health risks from non-ionizing radiation to humans remains limited.
"Few studies have been able to accurately measure exposure to magnetic magnitudes, etic non-ionizing radiation field," said De Kun Li of Kaiser Permanente Research Division in the United States.
The researchers asked women over the age of 18 with confirmed pregnancies to use a small (slightly larger than a deck of cards) magnetic field monitoring device for 24 hours.
Participants also kept a diary of their activities on that day, and were interviewed in person to better control possible confounding factors, as well as how typical their activities were on the day of monitoring.  Objective magnetic field measurements and pregnancy outcomes were obtained for 913 pregnant women, said Li, the study's principal investigator.
A miscarriage occurred in 10.4% of women with the lowest measured exposure level of nonionizing radiation from the magnetic field on a typical day, and in 24.2% of women with the highest level of exposure measured, a relative risk almost three times higher.
The reported miscarriage rate in the general population n is between 10 and 15 percent, Li said.
"This study provides evidence of a human population that non-ionizing radiation from the magnetic field could have adverse biological impacts on human health," said Li