Eating right is getting even more difficult. According to CNN Health, a new study reveals pesticide residue in both tap water and produce may be causing an upswing in food allergies.

Scientists have long known exposure to high levels of pesticides is toxic to humans. Now this study published in the Annals of Allergy, Asthma and Immunology indicates small concentrations of pesticides might also negatively impact human health.

The study found that people with high urine concentrations of dichlorophenols had an 80 percent higher chance of suffering some form of food allergy. Dichlorophenols are chemical compounds used for repelling pests from produce and also for adding chlorine to tap water.

Scientists think dichlorophenols affect beneficial bacteria in the human intestine that help support the immune system. Without those healthy bacteria protecting the gut, people are more likely to develop food allergies.

Dr. Kenneth Speath of The Occupational and Environmental Medicine Center said this discovery shows pesticides may have unpleasant effects on humans even in small doses:

Pesticides, and insecticides in particular, are inherently toxic to human health. This has been known for a long time in regards to large exposures. However, it is only in recent years that the harmful effects of low-level exposure from pesticides have begun to be revealed.

Fish, shellfish and peanuts are among the foods showing an increase in allergies. While the link between dichlorophenols and food allergies is not yet confirmed, the study shows a relationship between them is possible. It may also show a troubling new trend in pesticide related health problems for humans.

Writer Bennett Holleman contributed this report.