How Antibacterial Chemicals End Up in Your Food

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

August 12, 2010

Food not grown under organic standards may be contaminated with antibacterial chemicals.

RODALE NEWS, EMMAUS, PA—Should 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."

What's disturbing is that triclosan, which was found in the highest amounts in plant roots at both points in this study, and triclocarban are both used in thousands of consumer products. So for many people, this phenomenon may adding to frequent or daily exposure to these chemicals. Triclosan is a potential hormone disruptor, and there's some evidence that it could be contributing to antibiotic resistance in the general public—all at no benefit to the person buying antibacterial products, says Dolan. "Both the FDA and the American Medical Association, one of most trusted associations in the world, if not the U.S., have said that triclosan is no more effective in preventing illness than plain soap and water."

The good news is that Dolan's group, Food and Water Watch, has petitioned the Food and Drug Administration (FDA) to ban triclosan outright from use in consumer products, and another environmental nonprofit, the Natural Resources Defense Council (NRDC), recently sued the FDA to get the agency to enact tighter regulations on the chemical after three decades of delay. "We're hoping to get a more clarity on the issue," says Vivian Wang, an attorney at NRDC who help craft the suit. "As far back as the 1970s, we've recognized that this chemical was not proven to be safe or effective, but the FDA has kept delaying action on it."

And FDA action may be the only way to get triclosan out of our water. Municipal water authorities can't remove chemicals completely from water because it would simply be too costly to do so, says Dolan, so it's imperative that we keep them out of our water and sewage systems in the first place. Otherwise, we'll all continue to be exposed, whether we want to or not.

Here are a few ways to keep triclosan out of our water, and our food:

• Don't use them in the first place. Triclosan is technically considered a pesticide, and it's regulated for certain uses by the Environmental Protection Agency. Yet, the FDA allows it in kids' bath soaps, toothpastes, and even food cutting boards. "When I'm trying to convince people not to use antibacterial chemicals, the first thing I ask them is whether or not they know triclosan is a pesticide," says Dolan. "That usually gets people's attention. Pesticides are not something we want to lather all over ourselves."

• Know where they hide. In personal-care products, triclosan is required to be listed as an "active ingredient" on the ingredients panel. However, it's used in thousands of other products, such as clothing, shoes, countertops, the aforementioned cutting boards, baby changing tables in public restrooms, garden hoses—the list goes on and on. In these products, you'll probably see triclosan's trade names advertised. Avoid any product that claims to be treated with Microban, Microshield, or Biofresh. Some other common trade names include Irgasan, Aquasept, Sapoderm, and Ster-Zac.

• Eat organic. Sewage sludge is banned in organic food production. Therefore, choosing USDA-certified organic produce is one way to lower your exposure to triclosan. If you can't find affordable organic food at your grocery store, demand it!