Electromagnetic Fields Linked to Asthma in Kids

Aug. 1, 2011 -- Researchers seeking to explain the rising number of asthma cases in children have fingered a new suspect: electromagnetic fields (EMFs), energy that can’t been seen or felt that is generated by household appliances, electronic devices, cars, and power lines.

In a study, they found that babies born to women who are exposed to stronger EMFs during pregnancy had more than triple the risk of developing asthma compared to babies born to women exposed to weaker EMFs.

In other words, about 13% of children born to women in the group with the lowest EMF exposures developed asthma compared to about 33% of children born to women who had high EMF exposures.

“That’s a striking figure,” says David Savitz, PhD, a professor of community health and obstetrics and gynecology at Brown University in Providence, R.I. “That magnitude of association we don’t see very often. If it was correct, and that’s a big ‘if,’ that would be really startling.”

Savitz, who has studied the health effects of electromagnetic fields but was not involved in the research, says that while the finding is interesting, there’s no reason to give up using a hair dryer or microwave just yet.

He says that unlike contaminants like cigarette smoke or lead that are known to be dangerous, there’s little evidence that low-frequency EMFs, the kind measured in the study, are harmful.

“This has been very, very thoroughly studied, and it really is questionable whether it causes any health effects at any reasonable level,” Savitz tells WebMD. “It’s certainly not something that falls into the category of a known hazard.”

But Savitz and others acknowledge that all research has to start somewhere.

“There are a lot of important topics that started out looking pretty flaky and pretty unlikely. There was a time when it made no sense that smoking could be bad for you,” he says.

Other experts agree.

“The study appears to be well executed and the finding is surprising,” says Jonathan M. Samet, MD, a pulmonologist and epidemiologist at the Keck School of Medicine at the University of Southern California in Los Angeles.

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.