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Electromagnetic Fields Linked to Asthma in Kids

Study: Mom's Exposure During Pregnancy Raises Kids' Asthma Risk

Linking EMFs to Asthma in Kids

Researchers asked pregnant women who were members of the Kaiser Permanente Northern California health plan to wear magnetic field sensors around their waists for 24 hours.

The sensors took readings every 10 seconds, recording magnetic field levels of everything the women came into contact with during the day.

The sensors measured low frequency magnetic fields, which are generated by things like refrigerators, vacuum cleaners, hair dryers, cars, power lines, stoves, microwaves, computers, nearly anything that can be plugged in or runs on a motor.

They did not measure magnetic fields generated by cell phones or wireless networks, which operate at higher frequencies.

The sensors generated a total of 8,640 readings for each mother and baby.

Researchers then ranked those readings from the highest to lowest and picked out the middle number as a way to judge exposure.

Researchers don’t know why some women had higher exposures while others had lower exposures, but Savitz says roughly 10% to 20% of households in the U.S. would meet the criteria for high EMF exposures used in the study.

Researchers then followed the women and their children for up to 13 years.

Children were considered to have asthma if a doctor diagnosed them with the condition twice in the same year.

Compared to children of mothers in the low magnetic field group, who developed asthma at rates that were roughly comparable to the national average, those in the high group had a 350% increased risk of getting the condition, while those in the medium group had a 74% increased risk.

The association remained even after researchers adjusted their data for things that might independently influence the development of asthma in kids, like age, sex, early birth, low birth weight, breastfeeding, and a family history of the condition.

Researchers say women who are worried about EMFs can do simple things to lower their exposure.

“The problem with EMF is that you can’t see, smell it, you can’t touch it,” says study researcher De-Kun Li, MD, PhD, a reproductive and perinatal epidemiologist at the Kaiser Permanente Division of Research in Oakland, Calif. “But you can avoid those sources that we know about.”

“The great thing about EMF is that distance really helps,” Li says. For example, “When you turn the microwave on, don’t stand right next to it. Try to, when you use a hair dryer, try to use it far away from your tummy as much as you can.”

In the case of can openers, opting for a hand crank device, rather than an electric one, can lower EMF exposure.

In the case of vacuum cleaners, the study may be a good excuse to hand off the job to your partner.

The study is published in the Archives of Pediatric and Adolescent Medicine.


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