How Antibacterial Chemicals End Up in Your Food

New research finds food crops can take up toxic pesticides that come from antibacterial products.

By Emily Main


Risks of Antibacterial ChemicalsShould your food be antibacterial? A new study in the journal Environmental Science & Technology suggests that it could be—and that's not necessarily a good thing. The study found that the chemicals used in antibacterial products, as well as other drugs and pharmaceutical chemicals, are slipping past wastewater treatment plants and winding up in the water and fertilizer used on chemically grown crops, and they eventually wind up in the crops themselves. What's dangerous is that these chemicals have been linked to hormone disruption and may contribute to antibiotic resistance.

THE DETAILS: To simulate what would happen in a field in which biosolids (sewage sludge) and treated wastewater are used—common practices in the agriculture industry—the authors of the new study grew soybean plants in a lab using soil and water that contained levels of five chemicals similar to the levels found in municipal sewage and wastewater. The five chemicals used were triclosan and triclocarban (two ingredients commonly used in antibacterial products), the seizure medication carbamazepine, the antidepressant fluoxetine, and an antihistamine called diphenhydramine. After 60 days and again after 110, the plants' leaves, roots, and beans were tested. At the 60-day mark, the researchers found that both the roots and the above-ground parts of the plants had absorbed triclosan, triclocarban, and carbamazepine, with triclosan appearing in the highest amounts in the roots. Triclosan and triclocarban, but not carbamazepine, were detected in roots, leaves, and beans again at the 110-day test. The other two drugs weren't detected in significant levels at any point during the study.

WHAT IT MEANS: Basically, we're getting exposed to a chemical cocktail in food that should be safe to eat. The results of this study confirm what some observers have suspected, says Cathy Dolan, triclosan campaign manager for the nonprofit Food and Water Watch. "We've known for a while that triclosan is building up in earthworms that live in soil treated with sewage sludge," she says. "It's very evident that if it's in one part of the food chain, triclosan is very likely to wind up in another."