Low PPCP risk from water-reuse for irrigation – study

Levels of pharmaceuticals and personal-care products (PPCPs) in crops irrigated with treated wastewater were found to be “quite low” and probably not a health concern in a study carried out recently by the University of California – Riverside.

In a paper presented at the American Chemical Society (ACS) national meeting and exposition in Indianapolis on 9 September 2013, researchers led by Dr Jay Gan reported on what they termed the first study to focus on 20 PPCPs in multiple crops under realistic field conditions.

Gan explained that concerns had arisen about the health and environmental effects of residual PPCPs, especially over whether they might accumulate to dangerous levels in food crops. Previous studies on PPCPs in food crops were small in scale and conducted in laboratories or greenhouses.

The team chose eight vegetables that people often eat raw — carrots, bell peppers, tomatoes, cucumbers, lettuce, spinach, celery and cabbage. Gan explained that cooking and other processing can destroy PPCPs, and he wanted to determine the maximum amounts of PPCPs that consumers might ingest.

Xiaoqin Wu, a postdoctoral student in Gan’s laboratory, who gave the ACS presentation, said all the crops absorbed PPCPs, including a medication for epilepsy; triclosan, a common anti-bacterial ingredient; a tranquilizer; and caffeine. Leafy vegetables took up the highest amounts of PPCPs.

“The levels of PPCPs that we found in food crops growing under real-world conditions were quite low and most likely do not pose any health concern,” said Gan. “I think this is good news. These substances do not tend to accumulate in vegetables, including tomatoes and lettuce that people often eat raw. We can use that information to promote the use of this treated wastewater for irrigation.”