This is part of the book “Stéphane Foucart et les néonicotinoïdes. The World and disinformation 1“, where I present the reasoning developed by the journalist in the corpus. What is said in this chapter is my view on what the journalist writes. All quotes are translated (by me), except the ones marked between [ ] in the french version (french quotes are to numerous to be marked in this one).

Among insecticides, the NNI family included 7 molecules counting for approximately 40% of the world agricultural insecticide market: imidacloprid, thiamethoxam, clothianidin, dinotefuran, acetamiprid, nitenpyram and thiacloprid.

They are mostly used as seed coating. This would make them “systemic” insecticides, the substance circulating throughout the plant as it grows. (26)

The use of NNI as a coating would pollute large areas: 90% of the product is not used by the plant and “therefore remains in the soil and generally persists there for several years”. Being soluble in water, molecules can also be transported and permeate the surrounding environment. (26) (27) Sur et Stork (2003) estimate 80 to 98 % of the dose can stay in the ground. (64)

a. Accumulation in soils

NNIs can persist in soils for several years: 3 years for clothianidin and 10 years for imidacloprid. (36) These substances can thus be taken up by subsequent cultures. (33)

A study has indeed shown that “neonicotinoids show a potential for accumulation in the soil and can be taken up by subsequent crops up to at least two years after application”. Its authors recall, citing a 2005 study, that “imidacloprid was detected in 97% of 33 soil samples taken from untreated fields, but on which coated corn seeds had been used one to two years before. the taking of samples”. (13)

b. Diffusion in the environment

NNIs are said to have the capacity to diffuse in the environment, notably through “dust clouds generated during sowing, their solubility in water and their stability in soils”. (55) Several studies indeed show the presence of NNI in untreated areas.

Henry et al. 2015 and Botias et al. 2015

Thus, in a study published on November 22, 2015 (Henry et al. 2015), researchers have found imidacloprid in the nectar of rapeseed having not been treated with this substance… at rates comparable to or higher than those of thiamethoxam that had been administered to them. (27) British researchers have also found, in a study published on October 6, 2015 (Botias et al. 2015) that “the wild flowers that grow around treated fields absorb neonics and are also a major source of contamination for bees.” (27)

Humann-Guilleminot et al. 2019

Researchers led by Ségolène Humann-Guilleminot and Fabrice Helfenstein analyzed more than 700 plant and soil samples on 169 plots of 62 Swiss farms. (Humann-Guilleminot et al. 2019)
Were contaminated with NNI:

  • All conventional plots
  • 93% of ORGANIC plots (which have been organic for more than 10 years)
  • 80% of “areas of ecological interest”

The sole exposure to one of the investigated NNI, clothiandin, would represent a lethal risk for 5.3 to 8.6% of the 84 species studied and a sublethal risk for 31.6 to 41.2% of these organisms. The concentrations would be lower in untreated fields, which would present a sublethal risk for only 1.3 to 6.8% of the species considered.
This, without even taking into account the potential cocktail effects. The researchers therefore believe that NNIs represent an “environmental risk to adjacent untreated lands, over distances hitherto unknown, with consequences for non-target species.” (55)

Wintermantel et al. 2019

Researchers led by D. Wintermantel and V. Bretagnolle analyzed nectar and pollen taken from 300 rapeseed plots spread over the Plaine and Val de Sèvre workshop area. (Wintermantel et al. 2019) Samples were taken from these fields between 2014 and 2018. Despite the 2013 moratorium, the concentration of NNI showed “no downward trend”. The researchers found traces of NNI in 43% of the rapeseed samples analyzed. They found imidacloprid in 70% of plots in 2014, 5% in 2015, 90% in 2016, 30% in 2017, to rise to 55% in 2018. The vast majority of traces would be less than 1 part per billion. However, on 2 occasions in 2016, researchers reportedly found 45 parts per trillion of imidacloprid in the samples tested, which would be “five times the expected concentration of product in the nectar or pollen of treated oilseed rape.” The researchers estimated, from an EFSA model, that 12% of the plots were contaminated enough to kill 50% of the honeybees venturing there, the rate going up to 20% for bumblebees and 10% for solitary bees. (61) (64)

Pelosi et al. 2020

Pelosi et al. (2020) studied various soil samples and earthworms from the Plaine and Val de Sèvre workshop area. They found at least one pesticide in all of the samples analyzed; a mixture of at least one insecticide, fungicide and herbicide in 90% of the samples; and more than ten different pesticides in 40% of cases. The quantities are “spectacular: 43% of earthworms have an imidacloprid concentration of more than 100 ppb and 8% have more than 500 ppb”, which is several hundred times what would be found in the nectar of a rapeseed whose semen was coated with this substance. (69)

The distribution of NNIs in the environment is said to be such that they are found in most of the world’s honeys. A study published by Science that analyzed 198 honeys from all over the world found traces of NNI in 75% of them… (34)
The journalist concludes we have lost control of this technology. (27)

Page bibliography:

  • Botías, Cristina, Arthur David, Julia Horwood, Alaa Abdul-Sada, Elizabeth Nicholls, Elizabeth Hill, and Dave Goulson. “Neonicotinoid Residues in Wildflowers, a Potential Route of Chronic Exposure for Bees.” Environmental Science & Technology 49, no. 21 (November 3, 2015): 12731–40.
  • Henry, Mickaël, Nicolas Cerrutti, Pierrick Aupinel, Axel Decourtye, Mélanie Gayrard, Jean-François Odoux, Aurélien Pissard, Charlotte Rüger, and Vincent Bretagnolle. “Reconciling Laboratory and Field Assessments of Neonicotinoid Toxicity to Honeybees.” Proceedings of the Royal Society B: Biological Sciences 282, no. 1819 (November 22, 2015): 20152110.
  • Sur, Robin, and Andreas Stork. “Uptake, Translocation and Metabolism of Imidacloprid in Plants.” Bulletin of Insectology 56 (January 1, 2003): 35–40.