• BREAKING NEWS ABC shows live and on-demand -- Download the WATCH ABC app!

Study links asthma to electromagnetic fields

August 3, 2011 12:00:00 AM PDT
A new study suggests asthma is much more common in children whose mothers were exposed to high levels of electromagnetic fields during pregnancy.

Electromagnetic fields are emitted by power lines, fluorescent lights, microwaves and other household appliances including hair dryers.

Researchers at Kaiser Permanente in Oakland followed more than 600 pregnant women and had them wear a meter for one day that measured their average exposure. Children whose mothers had the highest exposure were three-and-a-half times more likely to develop asthma.

Critics say measuring exposure for only one day is not long enough to establish such a link and many factors influence asthma risk.