A new study published in Science of the Total Environment introduces a highly sensitive method for detecting neonicotinoid insecticides and their metabolites in water using just 12 mL of sample. Researchers from the University of Iowa applied this method to analyze water from private wells, surface waters, and wastewater effluent across Iowa, uncovering widespread contamination and potential ecological risks.

Key findings include:

• Clothianidin, imidacloprid, and thiamethoxam were detected in all surface water sites, with concentrations frequently exceeding EPA Aquatic Life Benchmarks for chronic toxicity.
• Private wells in agricultural areas showed higher levels of neonicotinoids than those in urban regions, with clothianidin and imidacloprid found in over 50% of samples.
• Wastewater effluent was identified as a significant source of neonicotinoids and their metabolites, particularly in effluent-impacted streams like Cardinal Creek and Burr Oak Creek.
• Several metabolites of neonicotinoids, including clothianidin-desmethyl and thiamethoxam urea, were detected in U.S. surface waters for the first time.
• The study highlights the first detection of flupyradifurone (FLU) in Iowa well water.

The research underscores the need for expanded monitoring of neonicotinoids and their transformation products, especially in regions with vulnerable aquifers and intensive agriculture. The newly developed method offers a practical and efficient tool for future environmental surveillance and risk assessment.

The full article is available at the Science of the Total Environment.