Electromagnetic Field Exposure Could Increase Risk of Asthma
According to the most recent statistics by the US Centers for Disease Control and Prevention, asthma rates are rising with an additional 4.3 million people being diagnosed with the breathing disease between 2001 and 2009. Paul Garbe, chief of the CDC’s Air Pollution and Respiratory Health Branch said the increase in cases is concerning, especially when several known factors that contribute to asthma (smoking, secondhand smoke exposure) have been on the decline. One area of interest to researchers is the contribution that electromagnetic fields (EMF’s) may have on the increased risk of developing the disease.
EMF Exposure May Contribute to Lowered Immune Response
Dr. De-Kun Li, a senior research scientist Kaiser Permanente in California, and colleagues studied the effects of EMF’s on 801 pregnant women who wore monitors to measure their exposure to low-frequency magnetic fields from power lines and appliances such as microwave ovens and hair dryers for 24 hours. The monitors did not measure high-frequency EMF exposure generated from devices such as cellphones or cellphone towers. The team used medical records to follow the children born to the women for 13 years.
During the follow-up, almost 21% of the children had developed asthma, most diagnosed before the age of 5. The children whose mothers had the highest EMF exposure levels (within the top 10%) were 3.5 times more likely to develop the disease versus those born to women with the least exposure. For the average population, Li said, children of women whose exposure levels were in the range of the bottom 10 percent in the study would have about a 13.6 percent absolute risk of developing asthma.
It is not clear why exposure to EMFs might increase the risk of asthma, but Li theorizes that they might contribute to lowered immune response based on findings from prior animal studies. Other possibilities include data that implicate higher miscarriage rates and poor semen quality when exposed to high levels of electromagnetic fields.
“Pregnancy is the most sensitive time for the fetus,” Li says. “Animal studies show that EMF can impact the immune system, and the latest research suggests that cells use magnetic fields to communicate with each other. If an external EMF comes into interfere with that, cell communication needed for normal development can be disrupted.”
"This really needs to be studied [further]," concludes Li, so that there may one day be new strategies for preventing the chronic disease in children. Until the findings can be replicated, experts agree that women should not worry about low-level EMF exposure but focus more on avoiding known risk factors such as cigarette smoke and lead.
Maternal Exposure to Magnetic Fields During Pregnancy in Relation to the Risk of Asthma in Offspring. De-Kun Li, MD, PhD; Hong Chen, MPH; Roxana Odouli, MSPH. Arch Pediatr Adolesc Med. Published online August 1, 2011. doi:10.1001/archpediatrics.2011.135