Detections of the Neonicotinoid Insecticide Imidacloprid in Surface Waters of Three Agricultural Regions of California, USA, 2010–2011

Abstract

Seventy-five surface water samples were collected from three agricultural regions of California and analyzed for the neonicotinoid insecticide imidacloprid. Samples were collected during California's relatively dry-weather irrigation seasons in 2010 and 2011. Imidacloprid was detected in 67 samples (89%); concentrations exceeded the United States Environmental Protection Agency's chronic invertebrate Aquatic Life Benchmark of 1.05 μg/L in 14 samples (19%). Concentrations were also frequently greater than similar toxicity guidelines developed for use in Europe and Canada. The results indicate that imidacloprid commonly moves offsite and contaminates surface waters at concentrations that could harm aquatic organisms following use under irrigated agriculture conditions in California.

Pesticide impact on aquatic invertebrates identified with Chemcatcher® passive samplers and the SPEARpesticides index

“…Neonicotinoids are frequently found in surface waters Main et al, 2014;Morrissey et al, 2015;Starner and Goh, 2012;Van Dijk et al, 2013), and Imidacloprid and Thiamethoxam were detected in the present study. While the Chemcatcher was not originally designed to collect compounds with log K OW b 2 (Kingston et al, 2000), successful sampling of more polar compounds with an SDB-RPS Empore disk as the receiving phase was reported previously (Stephens et al, 2005;Tran et al, 2007;Vermeirssen et al, 2008), and compounds with log K OW b 2 were also accumulated in quantifiable amounts by the Chemcatchers in the present study (Tables 1 and 2).…”

Pesticide authorization in the EU—environment unprotected?

“…EFSA (2008) thus admits: BOverall it is concluded that a high risk for aquatic organisms is indicated for the representative uses in orchards and tomatoes requiring substantial risk mitigation measures to reduce spray drift and runoff. BImidacloprid surface water concentrations (n=21) were reported for six countries across the EU, with concentrations reaching up to >200 μg/L (Mohr et al 2012;Starner and Goh 2012) and 28.6 % of all MIC SW exceeding the RAC SW ; these findings, again, challenge the overall protectiveness of the pre-authorization regulatory risk assessment in the EU.…”

Neonicotinoids: Systemic Insecticides and Systematic Failure

“…Given the widespread usage of neonicotinoids, it is not surprising that these compounds are increasingly detected in various environmental matrices. For example, a recent study published in BECT reported that 89% of the surface water samples collected from three agricultural regions in California contained imidacloprid, and 19% of the samples had imidacloprid concentrations that exceeded the USEPA risk threshold for aquatic life of 1.05 µg/L (Starner and Goh 2012). It has also been reported that the occurrence of neonicotinoids in surface water at environmentally relevant concentrations can negatively affect the physiology and survival rates of freshwater and marine animal species (Pisa et al 2015).…”