Using treated wastewater to grow crops has been commonplace, especially now when droughts are more common. However, researchers from the Pennsylvania State University assure that none of these compounds are at toxic levels, although the exact health risks on humans and animals remain unclear.

Lead researcher Alison Franklin studied wheat plants’ absorption of four compounds found in pharmaceutical and personal care products, including three types of antibiotics and one anti-seizure drug in the University Park wastewater treatment plant. Apparently, these compounds remain in active form since wastewater treatment facilities cannot completely filter these out.

“As I learned about pharmaceutical and personal care products in the environment, I became very interested in where these compounds were ending up,” Franklin notes. “What were the possible implications of these low level compounds in the environment on human, animal, and ecological health?”

Zachary Larson

The Living Filter at Penn State encompasses 600 acres of land split between two separate sites. Both contain agricultural and forested areas. This is the Astronomy site. Photo by Zachary Larson

They found that three of the compounds were in the plant parts. Two were only observed in the grain but not in the plant’s straw and the other one was in both the grain and straw.

Franklin explained that the concentrations were surprisingly low. Most of these compounds stayed on the outer surface of the plants and only tiny amounts were found in the plants’ grain and straw.

Zachary Larson

John (Jack) Watson, professor of Soil Physics & Biogeochemistry, is collecting soil samples at Penn State’s Living Filter site. Photo by Zachary Larson

The pH level of the soil and the plant, the species of the plant and the parts of the plant dictate how these plants take up the compounds.

“It is preferable for the compounds to be taken up into the non-edible portion, like straw, because it minimises risk,” says Franklin. “By looking at both plant parts the study provided more comprehensive information about the fate of these compounds.”

Franklin plans to identify the possible health problems these compounds may inflict on people and animals. The researcher is also currently searching for the best way to use water.