Agrochemical industrialists concealed the toxicity of pesticides for the developing brain – Liberation

New major scandal among manufacturers? Pesticide giants are accused by two Swedish researchers of having concealed the toxicity of their products for the human brain. The case is revealed by a consortium of European media, including the worldthe Bavarian radio et The mirror in Germany, the Swiss radio and television (SRF) in Switzerland and The Guardian UK.

In a study published Thursday, June 1 in the journal Environmental Health, the chemist Axel Mie (University of Stockholm, Karolinska Institute) and the toxicologist Christina Rudén (University of Stockholm) demonstrate that several pesticide manufacturers have evaded European authorities with unfavorable results of toxicity tests for the developing brain. Manufacturers had carried out these tests on their substances with a view to marketing authorization.

“If this information is correct, then it means that the pesticide manufacturers cheated to keep dangerous products on the market., alarmed MEP Pascal Canfin (Renew), chairman of the Committee on the Environment, Public Health and Food Safety in the European Parliament. He mentions a similarity to “dieselgate,” which came to light in 2015 when Volkswagen was accused of tampering with regulatory controls of its diesel engines to reduce apparent pollutant emissions. “We have been able to react for the automobile, we must do the same for pesticides”insists the MEP.

This case also echoes the oil companies, aware since the 1970s of the possibility of catastrophic climate change due to their products but who have maintained doubts to limit the use of fossil fuels. Or to the tobacco industry who, for decades, denied the deleterious effects of cigarettes on health.

Studies withdrawn from the European Authority

The two researchers, Axel Mie and Christina Rudén, who also published work on glyphosate at the end of 2022, carried out a titanic work of comparing data. They scrutinized, in thousands of pages of regulatory files, on the one hand the figures transmitted by the manufacturers to the American authorities and on the other hand, those sent to the European authorities. “They were thus able to identify nine pesticides for which several manufacturers (including Bayer and Syngenta) have conducted and submitted studies on the developing brain to the US Environment Protection Agency (EPA), but not to the European Food Safety Authority (EFSA)”reports the world.

The tests carried out on laboratory animals between 2001 and 2007 were therefore not taken into account by the European regulator. And these nine substances were authorized on the markets, for the most part at the end of the 2000s.

“This work must be considered all the more seriously since the impacts of pesticides on neurodevelopmental disorders have been unequivocally proven, not only on laboratory animals, but also on humans.comments the neurobiologist Yehezkel Ben-Ari, director of research emeritus at the National Institute of Health and Medical Research (Inserm), who did not participate in the work of the Swedish researchers. On autism in particular, but also on the intelligence quotient, we know that maternal exposures have an effect on the unborn child.

The example of the abamectine

In 2005 and 2007, the Swiss agrochemical giant, Syngenta, sponsored two tests on an insecticide: abamectin. Pregnant female rodents are exposed to the substance to determine the consequences of this exposure on the developing brains of their offspring. “These studies were not communicated by Syngenta to the European agencies, neither before nor after the initial authorization decision was taken in 2008, nor when the request was made in 2013 for a modification of the terms of use [de la substance]»note Axel Mie and Christina Rudén.

In 2016, a consortium of agrochemical firms applied for the renewal of this authorization. Here again, “the submitted file does not contain the studies on the developing brain, nor any reference to their existence”, say the researchers. It was only during the procedure, in 2019, that the experts of the rapporteur State, Austria, in charge of the preliminary expertise on behalf of the EU, requested these data from Syngenta, which provided them. provides. Finally, abamectin is reauthorized in Europe, but this time with drastic constraints, precisely linked to the impacts demonstrated by the Syngenta tests in 2005 and 2007, that is to say eighteen years and sixteen years older early.

Another worrying example: ethoprophos. “According to the assessment made by [les experts américains de] the EPA in January 2005, ethoprophos caused behavioral effects [sur les animaux de laboratoire] at all doses tested”, report the Swedish researchers. But Bayer scientists say they detect no effect in the same data. It is their conclusions, therefore in favor of the substance, that they forward to the European authorities. Without pointing out the divergent analysis of the American experts of the EPA. Ethoprophos is authorized in Europe in 2007.

Nearly a decade later, another agrochemical company, now owner of the molecule, requests the reauthorization of ethoprophos in Europe, traces Le Monde. This time, alerted by the researchers to the existence of a divergent analysis by the EPA, the European agency agrees with the opinion of its American counterpart, while noting that industrial data has not been transmitted to it. In 2020, ethoprophos is banned in Europe. Sixteen years after the proof of its toxicity for neurodevelopment.

Whistleblowers

Thus, Axel Mie and Christina Rudén acted as a whistleblower by warning the European authorities of the existence, across the Atlantic, of regulatory tests which had not been provided to them. For five of the nine pesticides identified, it was their vigilance that enabled EFSA to demand missing data from manufacturers. In total, four products have not been renewed to date, four are being re-examined, only abamectin having been re-authorized in 2023. A decision also challenged in court in early May by the NGO Pesticide Action Network Europe.

For their part, the manufacturers interviewed – in particular Bayer and Syngenta – claim to have scrupulously followed European regulations. According to them, it did not require, at the time of the facts, studies on the developing brain in the regulatory files. They also contest the fact that the studies not submitted to the European authorities were decisive. At the European Commission, it is recalled that the firms “must notify the Member States of the discovery of adverse effects [de leurs produits] under the 1991 Directive and the 2009 Regulation’. A requirement subject to interpretation, in particular on the characterization of an “adverse effect”. The information transmitted by the two Swedish researchers was nevertheless received with concern, the situation being even described as “serious problem” par a high representative of the European Commission.