Water purifier chemical may up food allergy risk
A byproduct of chemicals used to help purify water could be responsible for a rise in food allergies, according to a study.
Researchers have found that people exposed to high levels of dichlorophenols, produced when chlorine is added to water to ensure it is free of bugs, tend to be more prone to food allergies.
"Our research shows that high levels of dichlorophenol-containing pesticides can possibly weaken food tolerance in some people, causing food allergy," the Telegraph quoted Elina Jerschow, assistant professor of allergy and immunology at the Albert Einstein College of Medicine in New York, as saying.
"This chemical is commonly found in pesticides used by farmers and consumer insect and weed control products, as well as tap water," she revealed.
Jerschow and her colleagues looked at the incidence of food allergies among 2,211 people who were participants in the US National Health and Nutrition Examination Survey.
Those with the highest level of dichlorophenols in their urine were looked at in detail and found that their chance of having a food allergy - for example to eggs, peanuts, milk or shrimp - was 80 per cent higher than those with lower levels of dichlorophenols.
"In this population, we found consistent associations between high levels of dichlorophenol exposure and a higher prevalence of food allergies," the researchers wrote in the journal Annals of Allergy, Asthma and Immunology.
Among this group 550 or so people with the highest levels of the chemicals, their chance of having both a food allergy and an 'environmental' allergy - for example to pollen - was 61 per cent higher.
"Previous studies have shown that both food allergies and environmental pollution are increasing in the United States. The results of our study suggest these two trends might be linked, and that increased use of pesticides and other chemicals is associated with a higher prevalence of food allergies," Dr Jerschow said.
However, she said that further studies were necessary "to confirm this link".
If firm evidence emerged that dichlorophenols triggered allergies, Dr Jerschow cautioned that avoiding tap water was unlikely to solve the problem.
Other dichlorophenol sources, such as pesticide-treated fruits and vegetables, may play a greater role in causing food allergy, she noted.