by: David Gutierrez
Previous studies have shown that crops grown directly in animal manure can absorb veterinary drugs, and that cabbages grown hydroponically can absorb human drugs. To simulate more natural agricultural conditions, researchers grew soybeans — the second most widely planted crop in the United States — in regular soil. Half the crops were fertilized with solid waste, while the other half were irrigated with chemical-spiked water. In order to simulate the reclaimed sewage or wastewater commonly used in industrial agriculture, the researchers spiked water and waste with the drugs carbamazepine (an anticonvulsant), diphenhydramine (Benadryl) and fluoxetine (Prozac), along with the common antimicrobial chemicals triclosan and triclocarban.
Using mass spectrometry, the researchers then analyzed the plants' tissues just before flowering and after the production of beans. The plants absorbed carbamazepine, triclocarban and triclosan from both soil and water, although absorption from water was greater. All three chemicals accumulated in root tissues, stems and leaves, while the antimicrobial compounds also accumulated in the beans. Diphenhydramine and fluoxetine accumulated in low concentrations in the roots.
The health effects of this absorption remain unknown, but they could be severe. Triclosan, for example, has been shown to build up in the bodies of humans and other animals.
"Triclosan disrupts hormones, can affect sexual function and fertility, and may foster birth defects," write Frank Lipman and Mollie Doyle in their book Spent: Revive: Stop Feeling Spent and Feel Great Again.
"If you find those compounds in the plant, what are they going to do to the plants or to animals that eat the plants?" researcher Chenxi Wu asked.