A new study from Washington University in St. Louis has revealed that inactive ingredients in herbicides used in agriculture could be major contributors to harmful byproducts in drinking water, necessitating a reevaluation of current water treatment practices.
Inactive ingredients in everyday agricultural products may pose unexpected risks to drinking water, according to new research from the McKelvey School of Engineering at Washington University in St. Louis. The study, published in the April 15 issue of Water Research, suggests that these seemingly benign chemicals can transform into harmful byproducts during water treatment processes, raising significant public health concerns.
The research, led by graduate student Jean Brownell under the guidance of Kimberly Parker, an associate professor of energy, environmental & chemical engineering, focuses on amines used in herbicides.
Inactive amines, incorporated as stabilizing agents to enhance the solubility and reduce the drift of these chemicals, may play a far more substantial role than previously recognized in forming nitrosamines, which are hazardous byproducts resulting from water disinfection.
“Everybody needs healthy food to eat and clean water to drink, so there’s clear motivation for us to look at how herbicides used in agriculture impact water treatment downstream,” Brownell said in a news release. “We need herbicides to support effective modern farming, but we also need to examine our assumptions about these products to make sure we haven’t missed side effects that might pose risks to people’s health and safety.”
Brownell’s work involved comparing the annual use of herbicidal amines with other known nitrosamine precursors, such as pharmaceuticals ranitidine and metformin. She found that the prevalence of amines in herbicides has surged over recent decades, especially affecting regions like the Midwest.
The study suggests that these inactive agents could be significant contributors to nitrosamine formation, posing serious health hazards even at trace levels.
“The conventional wisdom was that the main source of nitrosamine precursors was consumer products – things like pharmaceuticals, fabric dyes and so on – that enter the environment via municipal wastewater, and agricultural runoff wasn’t a big source,” Parker added. “But when agrochemical practices change, we can’t keep applying old results. We need to evolve our studies and question our assumptions to make sure what we’re assuming is either truly generalizable or alternatively, needs to be appropriately applied to local areas.”
This revelation underscores the necessity for continuous monitoring and reevaluation of agricultural practices and their impact on water safety. Brownell stressed that evaluating trends in herbicide formulation and usage over the past 20 years is critical to understanding their role as chemical precursors of DBPs.
The findings advocate for collaborative efforts in collecting and sharing high-quality data from farmers and regulatory agencies to ensure the ongoing protection of public health.
“We do need to rethink our assumptions that led us to think agriculture is unimportant for nitrosamine precursors, but this needs to be followed up with field research to test and verify these findings,” Parker concluded.
The ongoing investigation emphasizes the intricate balance between agricultural innovation and environmental health, urging a proactive approach in safeguarding drinking water supplies against emerging contaminants.
Source: McKelvey School of Engineering, Washington University in St. Louis