Wastewater May Contaminate Crops with Potentially Dangerous Pharmaceuticals

Reclaimed wastewater used to irrigate crops is contaminated with pharmaceutical residues that can be detected in the urine of those who consumed such produce.

Investigators at the Hebrew University of Jerusalem (Israel) and their colleagues at the Hadassah Medical Center (Jerusalem, Israel) focused this proof-of-concept study on the anticonvulsant drug carbamazepine, which is ubiquitously detected in reclaimed wastewater, highly persistent in soil, and taken up by crops.

They worked with 34 people who were divided into two groups. The first group was given reclaimed wastewater-irrigated produce for the first week, and freshwater-irrigated vegetables in the following week. The second group consumed the produce in reverse order. The investigators measured carbamazepine levels in the fresh produce and in the participants' urine.

Results published in the March 29, 2016, online edition of the journal Environmental Science and Technology revealed that individuals who consumed reclaimed wastewater-irrigated produce excreted carbamazepine and its metabolites in their urine, while subjects who consumed fresh water-irrigated produce excreted undetectable or significantly lower levels of carbamazepine.

This “proof of concept” study demonstrated that human exposure to xenobiotics occurred through ingestion of reclaimed wastewater-irrigated produce, providing real world data, which could guide risk assessments and policy designed to ensure the safe use of wastewater for crop irrigation.

"In a randomized controlled trial we have demonstrated that healthy individuals consuming reclaimed wastewater-irrigated produce excreted carbamazepine and its metabolites in their urine, while subjects consuming fresh water-irrigated produce excreted undetectable or significantly lower levels of carbamazepine," said first author Dr. Ora Paltiel, director of the school of public health and community medicine at the Hadassah Medical Center. "Treated wastewater-irrigated produce exhibited substantially higher carbamazepine levels than fresh water-irrigated produce. It is evident that those who consume produce grown in soil irrigated with treated wastewater increase their exposure to the drug. Though the levels detected were much lower than in patients who consume the drug, it is important to assess the exposure in commercially available produce."

Related Links:
Hebrew University of Jerusalem
Hadassah Medical Center