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Asthma Health Center

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Electromagnetic Fields Linked to Asthma in Kids

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


Samet recently led a World Health Organization panel that concluded that EMFs from cell phones and other wireless devices could possibly cause cancer.

The current study didn’t account for EMFs from cell phones or wireless networks, which emit higher-energy frequencies than were measured in the study.

Samet says that based on what we know about the development of asthma, it’s hard to understand how EMFs might play a role. Repeating the study, he says, will be an important next step.

Previous studies have shown that EMFs may adversely affect the immune system.

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.

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