News | August 05, 2011

Study Finds Exposure to Magnetic Fields in Pregnancy Increases Asthma Risk

August 5, 2011 – Women with high exposure to magnetic fields during pregnancy may have a higher risk of asthma in their children, according to a Kaiser Permanente study appearing online in the Archives of Pediatrics & Adolescent Medicine.

In this prospective study, researchers compared the daily magnetic field (MF) exposure of 801 pregnant women in Kaiser Permanente Northern California and used electronic medical records (EMR) to follow their children for 13 years to see which children developed asthma. The study found that women with high magnetic field exposure in pregnancy had a more than threefold risk of asthma in their offspring compared with mothers whose exposure level was low.

This is the first study to demonstrate a link between maternal magnetic field exposure in pregnancy and the risk of asthma in offspring. Previous research has found that magnetic fields – generated typically by power lines and appliances such as microwave ovens, hair dryers and vacuum cleaners – could lead to miscarriage, poor semen quality, immune disorders and certain type of cancers. Recently, the International Agency for Research on Cancer, a WHO agency, classified radio frequency electromagnetic fields (RF-EMF) as a possible carcinogen.

"While the replication of the finding is needed, the message here is exposure to electromagnetic fields is not good, and we need to pay attention to its adverse effect on health," said study lead author De-Kun Li, M.D., Ph.D., a reproductive and perinatal epidemiologist at the Kaiser Permanente Division of Research in Oakland, Calif. Li published the original study in 2002 that found high MF exposure can lead to miscarriage.

The prevalence of asthma has been steadily rising since the 1980s, making it the most common chronic condition among children. Thirteen percent of children under 18 have asthma, which is caused by malfunction of the respiratory organs and the immune system.

"EMF exposure is ubiquitous. Because of the widespread exposure, any adverse health effect of EMF could impact many people and cause a serious public health problem," said Li.

Studying the EMF health effect has been difficult because everyone is exposed to EMF at some level, so there is no truly "unexposed control group" for easy comparison, researchers said. Health researchers must rely on comparing those with high EMF exposure levels to those with low EMF exposure levels to detect potential adverse EMF effects, Li said.

Women in this study wore a small meter during their pregnancy that measured their daily exposure to low frequency magnetic fields from electricity-related sources such as microwave ovens, hair dryers, vacuum cleaners, fans, coffee grinders, fluorescent light bulbs, power lines and transformer stations. This study did not measure high frequency (radio frequency) magnetic fields from wireless networks, wireless towers and wireless devices such as cell phones and smart meters. The researchers adjusted for study participants who lived near freeways but it did not change the results of the EMF-asthma association.

"In this study, we observed a dose-response relationship between mother's MF level in pregnancy and the asthma risk in her offspring. In other words, a higher maternal MF exposure during pregnancy led to a higher asthma risk in offspring," Li said.

In this new study, the researchers also found that two known risk factors for asthma, maternal history of asthma and being the first-born child, exacerbated the magnetic field effect on the asthma risk. "This finding further supports the MF-asthma association," said Li.

"The best way to reduce your magnetic field exposure is distance. Magnetic field strength drops dramatically with increasing distance from the source," said Li. "So pregnant women should try to limit their exposure to known MF sources and keep distance from them when they are in use."

The study was funded in part by the California Public Health Foundation. Co-authors on the study include Hong Chen, MPH, and Roxana Odouli, MSPH, both of the Kaiser Permanente Division of Research.

For more information: www.dor.kaiser.org/

 

Related Content

Philips Introduces Technology Maximizer Program for Imaging Equipment Upgrades
Technology | Imaging | January 17, 2018
January 17, 2018 — Philips recently announced the launch of Technology Maximizer, a cross-modality program designed t
Russian Team Developing New Technology to Significantly Reduce MRI Research Costs
News | Magnetic Resonance Imaging (MRI) | January 16, 2018
January 16, 2018 — Researchers from the NUST MISIS Engineering Center for Industrial Technologies in Russia have deve
Transpara Deep Learning Software Matches Experienced Radiologists in Mammogram Reading
News | Computer-Aided Detection Software | January 12, 2018
Deep learning and artificial intelligence improves the efficiency and accuracy of reading mammograms, according to...
Fat Distribution in Women and Men Provides Clues to Heart Attack Risk
News | Women's Health | January 11, 2018
January 11, 2018 – It’s not the amount of fat in your body but where it is stored that may increase your risk for hea
Smartphone Addiction Creates Imbalance in Brain
News | Mobile Devices | January 11, 2018
Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet,...
Emergency Radiologists See Inner Toll of Opioid Use Disorders

Rates of Imaging Positivity for IV-SUDs Complications. Image courtesy of Efren J. Flores, M.D.

News | Clinical Study | January 11, 2018
January 11, 2018 – Emergency radiologists are seeing a high prevalence of patients with complications related to opio
Minimally Invasive Treatment Provides Relief from Back Pain

Lumbar spine MRI showing disc herniation and nerve root at baseline and one month after treatment

News | Interventional Radiology | January 11, 2018
The majority of patients were pain free after receiving a new image-guided pulsed radiofrequency treatment for low back...
CT Shows Enlarged Aortas in Former Pro Football Players

3-D rendering from a cardiac CT dataset demonstrating mild dilation of the ascending aorta.

News | Computed Tomography (CT) | January 11, 2018
Former National Football League (NFL) players are more likely to have enlarged aortas, a condition that may put them at...
Study Finds No Evidence that Gadolinium Causes Neurologic Harm

MR images through, A, C, E, basal ganglia and, B, D, F, posterior fossa at level of dentate nucleus. Images are shown for, A, B, control group patient 4, and the, C, D, first and, E, F, last examinations performed in contrast group patient 13. Regions of interest used in quantification of signal intensity are shown as dashed lines for globus pallidus (green), thalamus (blue), dentate nucleus (yellow), and pons (red).

News | Contrast Media | January 11, 2018
January 11, 2018 — There is no evidence that accumulation in the brain of the element gadolinium speeds cognitive dec
Overlay Init