A chemical found in pesticides and tap water might help explain why so many more people have food allergies nowadays compared to in the past.

A new study links high levels of dichlorophenols, a chemical used in pesticides and to chlorinate water, to food allergies in people.

The findings are important because food allergies are on the rise, the researchers say.

"Our research shows that high levels of dichlorophenol-containing pesticides can possibly weaken food tolerance in some people, causing food allergy," said allergist Dr. Elina Jerschow. "This chemical is commonly found in pesticides used by farmers and consumer insect and weed control products, as well as tap water."

The researchers looked at 10,348 participants in a U.S. National Health and Nutrition Examination and found those with dichlorophenols in their urine were more likely to report food allergies.

The study was published in the Annals of Allergy, Asthma and Immunology.