Drought conditions and the overall lack of fresh water have contributed to the increased use of reclaimed wastewater by agricultural producers. A study by Israeli researchers first published in Environmental Science & Technology compared the relative amounts of an anticonvulsant drug in crops irrigated with wastewater with fresh-water irrigated produce. The news isn’t reassuring. And it gets worse, because we pass on the drugs in our own waste, completing the pee-to-food-to-pee loop.
The researchers looked for significant levels of the pharmaceutical carbamazepine, an anticonvulsant drug prescribed for epilepsy, found in most reclaimed wastewater. The drug is a hardy substance, lasting in soil and easily absorbed by plants, so it’s a good choice for testing; but it’s not the only drug that’s absorbed by crops. When they tested for carbamazepine in the urine of test subjects who had eaten produce irrigated with reclaimed wastewater, researchers found the drug in the subjects’ urine. Identical testing with crops irrigated with fresh water revealed much lower or undetectable amounts of the drug in the pee of those people.
One piece of good news from the study was that when the researchers switched people who had been eating wastewater-irrigated crops back to produce irrigated with fresh water, the drug levels in their urine dropped back to normal. So at least that’s an indication that excreting the drugs may really get rid of them if you switch to non-urine-irrigated produce.
The bottom line is, watering crops with other peoples’ and animals’ urine does more than just irrigate the plants; it loads them up with drugs, too. It’s interesting to imagine the package or grocery store labeling that may result.
