Researchers are linking the use of pesticides used to purify tap water to food allergies that are becoming a significant problem in the Western world.
Allergy to eggs, peanuts, milk and shellfish increased by 18% between 1997 and 2007 in the U.S. sending 9500 children to the hospital each year under the age of 18, according to statistics from the Centers for Disease Control (CDC).
Researchers wanted to find out if there was a correlation between the use of a group of pesticides known as dichlorophenols used to chlorinate water and spikes in food allergies that seem to parallel each other.
The pesticides are also used on fruits and vegetables and for weed and insect control in agriculture.
For the study, published in the Annals of Allergy, Asthma and Immunology, researchers looked at 10,348 participants in a US National Health and Nutrition Examination Survey 2005-2006.
Among the more than 10,000 participants, 2,548 had dichlorophenols measured in their urine and of those, 2,211 were included in the study.
More than 1500 of the participants had allergies – 411 to food. Another 1,016 had an environmental allergy.
Allergist Elina Jerschow, M.D., M.Sc., ACAAI fellow and lead study author suggests there may be a link between food allergy and pesticide use in tap water, but explains other exposure to dichlorophenols from fruits and vegetables might play an even bigger role.
Another possible explanation is that kids are exposed to fewer germs as a result of living in urban settings.
“For example, kids living on farms are exposed to more bacteria and have less allergies. It could be that dichlorophenols prevent us from being exposed to more bugs, “Jerschow said in a press release.
The study supports recent suggestions from researchers that pesticide exposure can damage the immune system, increasing the chances of allergy. Exposure to more chemicals in the environment has also been linked to higher rates skin allergies and sensitivity. Pesticides are also known to aggravate asthma.
The most severe form of food allergy from anaphylaxis can cause tongue swelling, respiratory distress and death. Sensitivity to environmental toxins that are not true allergies can cause vague symptoms that can be difficult to pinpoint.
The authors concluded, “Excessive use of dichlorophenols may contribute to the increasing incidence of food allergies in westernized societies.”
The finding doesn't prove the pesticides in tap water cause food allergies, but adds to a growing body of evidence that pesticides - no matter how we’re exposed to them - could be contributing to food and environmental allergies in ways that are not yet completely understood.