Neonicotinoid insecticide residues in subsurface drainage and open ditch water around maize fields in southwestern Ontario

Abstract

Neonicotinoids are widely used class of insecticides. Most are seed treatments and during planting active ingredient may be abraded and lost in fugitive dust. Much of this active ingredient contaminates surface waters, exposing aquatic organism to potential ill effects. This study examines concentrations of neonicotinoids appearing in tile drains and open ditches around commercial maize fields around planting time where neonicotinoid seed treatments had been used. This sample set represents surface water leaving the point of origin, for which data are sparse. Clothianidin was found more often than thiamethoxam and at higher concentrations; at a median concentration of 0.35 ng/mL in tile drain water and almost twice that (0.68 ng/mL) in ditches into which the tiles are draining after applications of 19 g/ha on seed. This concentration reveals a 40 to 50 fold dilution for neonicotinoid residues between the points where they leave the field in which they were applied and when they are found in nearby streams in a similar ecosystem. Our data support that for a no-observed-effect concentration of 0.3 ng/mL for thiamethoxam there would be between a 1.6 and 100-fold margin of safety to mayflies in most streams if fugitive dust on pneumatic planters were properly mitigated.

Neonicotinoid contamination in tropical estuarine waters of Indonesia

“…The results also showed that neonicotinoids could be detected at more sampling points in November 2020 (eight locations) than in August 2021 (four locations) ( Figure 1 ). This may have been because the rainy season occurs in November, causing the release of neonicotinoids stored in soils after the previous rice cultivation season into rivers/creeks through runoff after rainfall events ( Sánchez-Bayo and Hyne, 2014 ; Schaafsma et al., 2019 ; Zhang et al., 2019 ). Rainfall also increases the turbidity of water, thus preventing the photodegradation process of neonicotinoids in water ( Sánchez-Bayo and Hyne, 2014 ).…”

“…Sample collection was performed using a stainless-steel bucket attached to a rope. The sample collection method followed the methods of Schaafsma et al. (2019) with some modifications.…”

“…Neonicotinoids are a class of systemic insecticides with a chemical structure similar to nicotine and work by attacking the nervous system of insect pests ( Buszewski et al., 2019 ), consisting of acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam. Despite their utility in eradicating pests in rice cultivation, the application of neonicotinoids, however, also resulted in the pollution of environmental waters surrounding the agricultural lands ( Hano et al., 2019 ; Schaafsma et al., 2019 ) due to their properties, i.e., high water solubility, low absorbance by soils, resistance to hydrolysis, and having a long half-life ( Morrissey et al., 2015 ). These properties cause the neonicotinoids to be more persistent so that they can easily be transferred from rice fields to the nearby aquatic environment.…”

“…To date, most studies on neonicotinoid occurrence in environmental waters were conducted in sub-tropical and temperate zones such as in Europe (e.g., Iancu et al., 2019 ; Postigo et al., 2021 ; Sousa et al., 2020 ), Australia (e.g., Sánchez-Bayo and Hyne, 2014 ), Canada (e.g., Anderson et al., 2015 ; Main et al., 2014 ; Schaafsma et al., 2019 ; Struger et al., 2017 ), USA (e.g., Berens et al., 2021 ; Hladik and Kolpin, 2015 ), China (e.g., Naumann et al., 2022 ; Zhang et al., 2019 ), and Japan (e.g., Hano et al., 2019 ; Hayashi et al., 2021 ; Yamamuro et al., 2019 ), and very few were performed in tropical region (e.g., Bonmatin et al., 2019 ; Bonmatin et al., 2021 ; Lamers et al., 2011 ; Wan et al., 2021 ). Moreover, very few studies focused on estuarine waters (e.g., Gonzalez-Rey et al., 2015 ; Hano et al., 2019 ; Sousa et al., 2020 ; Yamamoto et al., 2012 ) where pollutants originating on land will be accumulated before they are transferred to the sea.…”

A new method to assess the acute toxicity toward honeybees of the abrasion particles generated from seeds coated with insecticides

“…About the active ingredient applied to the seed, only approximately 5% is taken up by the crop while most of it remains in the soil and leaches to ground/surface waters [36][37][38][39][40][41][42][43]. Furthermore, the drilling machine used for sowing releases into the atmosphere particulate matter produced from abrasion of seed coatings, that contains 1-2% of the total amount of pesticide applied in the field [44].…”