A study by Li (details below) found that women who were exposed to elevated magnetic fields during pregnancy, increased their risk of having a child with asthma significantly. Those who were exposed to levels of 0.2 microtesla (a fairly low field) had children who were more than 3 times more likely to develop asthma than those in fields of 0.03 microtesla. The higher the exposure the higher the risk. Women who were expecting their first child seemed to be particularly susceptible. The children were followed up for up to 13 years. Olle Johansson, a specialist in diagnosing health problems as a result of magnetic field effects believes that electromagnetic fields disturb the immune system, making people more vulnerable to all sorts of health problems.
If anyone in your family is pregnant, especially with a history of immune system problems, or allergies, you may want to check out your home for magnetic field levels. If you are moving to a house near a powerline or substation, and you wish to have more children, it would be worth checking the field levels in the house first.
References
Li, D-K, Chen H & Adouli R, Maternal Exposure to Magnetic Fields During Pregnancy in Relation to the Risk of Asthma in Offspring - Arch Pediatr Adolesc Med, Published online August 1, 2011 as doi:10.1001/archpediatrics.2011.135 - See reference PubMed
Johansson O, Disturbance of the immune system by electromagnetic fields - A potentially underlying cause for cellular damage and tissue repair reduction which could lead to disease and impairment - athophysiology 2009; 16: 157-177 - See reference PubMed
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