Autism and pesticides: a misuse of scientific rigour

Autisme et pesticides – Aut’Créatifs, 9 septembre 2019.
English Translation by Emily Gray.

Autism and pesticides: a misuse of scientific rigour

On September 9, 2019, Autisme Montreal, the David Suzuki Foundation and l’Alliance pour l’interdiction des pesticides systématiques published what they referred to as a “literature review” with the title, “Alarming increase in the prevalence of autism: Should we worry about pesticides?” This report states that pesticides have an impact on the prevalence of autism.

Very disappointed, deeply concerned

We are strongly disappointed that the David Suzuki Foundation is associated with ideas that risk tarnishing its credibility. Because since its publication, this report is under criticism of eminent scientists, such as M. Sébastien Sauvé, professor of environmental chemistry at University of Montreal, and Dr. Éric Fombonne, internationally renowned child psychiatrist and epidemiologist to whom we owe the redaction of the research associating autism with the MMR vaccine in the prestigious scientific journal the Lancet.

A serious study, this time issuing from a veritable and renowned chair of university research and appearing in Jama psychiatry (psychiatry’s most prestigious journal,) just recently demonstrated that the rise in the number of autism diagnoses is connected for the most part  to the fact that the diagnostic criteria are being interpreted more and more liberally and lightly. In other words, the autism diagnosis was given to a growing number of people who are less and less different that the non-autistic population. That has evidently absolutely nothing to do with pesticides!

Autism Montreal’s usual catchphrase

Autism Montreal having apparently furnished the studies underlying this publication, it should not be surprising that all of this is, “as though by chance,” in favour of the idées-fixes (rigid opinions) that AM has been spreading for a number of years about autism. These  idées-fixes can be summarized here: Nobody is born autistic; A person becomes autistic by being poisoned by “toxins” (vague term comprising sugar, corn, colouring, yeast, pesticides, and even more); These said toxins cause “oxydative stress” and “mitrochondrial problems” resulting in autism.

These are what we politely call “alternative facts”, that not only deny a genetic basis to autism, but that have also never been validated by the scientific community. Note that by the way, fixations and “special interests”  are really not exclusive to autistic people!

From the beginning, the joint report three organisms was biased in favour of “controversial” theories another “polite” term, of Autism Montreal, whose pseudoscientific jargon is found in its pages. In this regard, it must be known that Autism Montreal is not at all a research chair in autism, but essentially a group of parents offering various services to autistic people and their families.

Major methodological gaps

Let’s go a bit deeper. The joint report talks about a “literature review.” However, by reading the methodology, it’s clearly specified that this analysis is not a meta-analysis and isn’t exhaustive of the scientific literature on the subject. It is also stated that the research tool used was Google Scholar. Therefore, multiple studies on the subject may have been omitted given the poor methodology.

The report affirms that pesticides cause autism. However, in the methodology, it’s written: “exploring if the correlations imply equally a causation.” Therefore, contrary to their conclusion, the authors affirm that they have no proof whatsoever that pesticides cause autism. The studies show only a correlation between autism and pesticides, that is to say, in our society, there is an increase in both pesticide use and autism prevalence. However, making these correlations between two variables is very simplistic. For example, a linear correlation exists between a fall in the number of divorces and a fall in margarine consumption, between Miss America’s age and the number of murders, or between the risk of death by falling down stairs and the purchase of an iPhone. In other words, almost anything can be connected to anything else. The use of a simple correlation to show a causality link is a major error in statistics and also in methodological, scientific, and ethical rigour.

The report claims that it was based on 158 studies. However, according to annex 3, they actually only used 6 different studies, and these studies in no way assert that there is a causal link between pesticides and autism. Its authors only observed that the two variables are rising throughout time. As mentioned, this is in no way proof of a cause-and-effect link. Added to this is the fact that some data is not independent and that evaluations for diagnoses are not always based on recognized protocols. Finally, this research used no control group, which is nevertheless an essential criterion in scientific research to be able to prove a cause-and-effect relationship.

In short, the fundamentals upon which this report is based are weak, questionable, and biased.


The fact remains that pesticides are indeed dangerous substances. They are poisonous to plants, animals, even for farm workers and the environment in general. This industry is far from being known for its good sense of ethics?. In Quebec, whistle-blower agronomist Louis Robert revealed in 2018 that agronomists, including state-employed agronomists, were receiving industry bonuses to incite farmers to buy large amounts of their products, including atrazine, a pesticide banned in Europe since 2004 due to its high toxicity. Some members of Aut’Creatifs are firm supporters of banning them altogether. However, it is not Aut’Creatifs’ mandate to take an official position on the subject.

That pesticides can cause neurological problems, and that some of these problems might be mistakenly equated with autism, all of that is possible. But that does not mean that that there is a cause-and-effect link between pesticides and autism. The joint report does not show any serious indication to that effect.

We therefore denounce what is another “fake news” item by which autistic people have been exploited for political and promotional purposes. We also want to disassociate ourselves from the alarmist discourse about autism contained in this report: ”alarming rise,” “deficits,” “undesirable problem,” etc. This kind of language stigmatizes autistic people and greatly harms their development and fulfillment. That, too, is a poison.

Antoine Ouellette, Lucila Guerrero, Mathieu Giroux, Stephan Blackburn, Lucie Latour

Le Conseil d’administration



Telling The Story of Autism Differently

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Recommendations for Autism Terminology in the Media

PDF version to download: Telling The Story of Autism Differently

Knowledge of Autism is in a great state of evolution. Despite this, a large part of the population still ignores what it means to be autistic, and misconceptions arising from popular myths are widespread. As a result of this misinformation, terminologies referring to the condition of autism and autistic people are quite variable. Often, they take respectful forms, but other times, they can be devaluing.

This document will serve as a guide to any person working in the domain of communications. According to the principles of non-discrimination and the right to fair information, the use of adequate language is recommended. These proposals received the support of Doctor Laurent Mottron. We thank him for his support.

Dr. Laurent Mottron, M.D., Ph.D., DEA, is a researcher at Rivieres-des-Prairies Hospital and at L’Insitut Universitaire en Sante Mentale of Montreal, and is professor at the Department of Psychiatry at the University of Montreal. He specializes in research on autism.

Recommended Terminology

Terminology to Avoid

In General

-Autism/Autistic condition
-Neurodevelopmental Variation
-Neurological variation

In General

-Problem, illness, affliction, pathology
-Autism Spectrum Disorder
-Pervasive developmental disorder

About the Person

-Autistic person
-Person of autistic spirit or nature
-To identify as/be autistic
-Describe capacities, talents, and aptitudes of a person; in context.
-Autonomous/non-autonomous person

About the Person

-Person affected by autism/ suffering from autism
-Person with autism/in the situation of autism
-To admit/confess one’s autism
-Person with autism spectrum disorder/ASD
-High/Low functioning autistic


-Characteristic, particularity, trait
-Different neurology and sensorial sensitivities
-Particular interest, focused intelligence, passion
-Rituals, gestures
-Unconventional learning
-Sense of humor unique to one’s structure of thought
-Variant of feeling and expression of empathy
-Autistic functioning


-Deficiency, incapacity, deficit
-Obsession, restricted interests
-Ticks, manias
-Resistance to teaching methods
-Doesn’t smile, no sense of humor
-Lacking empathy
-Abnormal functioning

To contribute to the breaking of myths and stereotypes, here are some guidelines to follow:

-Avoid generalizations. Make reference to the diversity of autistic people and humanity’s neurodiversity in general.

-Avoid using the word “autistic” to describe public attitudes of lacking communication, or as an adjective with the goal being negative criticism or insult. For example: “The autism of radio Canada journalists,” Dreuz info, November 16, 2014.

-Avoid making comparisons to the “Rain Man” archetype and exaggerating the talents and intelligence of autistics.

-Avoid blaming parents, society, or the environment.

-Avoid speaking of autism as an epidemic, a social ill, or a tragedy. Describing autism this way reflects on autistics themselves. They suffer damage to their self-esteem, especially for children who often do not yet fully understand, and are vulnerable to discrimination.

-We recognize that, like all human beings, each autistic person possesses a potential, gifts, aptitudes, qualities, etc, as well as limits, weaknesses, faults, challenges to overcome, etc. Autistic people contain as much diversity among them as do non-autistic people.

-Autism is a human characteristic which may or may not be accompanied by dysfunctions. In and of itself, autism is not an illness. For these reasons, vocabularies of pathology are to be avoided, including the word, “disorder.”

-Autism is an integral part of the person. It is not an accessory. An autistic person, therefore, does not “have autism.”

-Expressions such as “an ASD person” are incorrect from a linguistic standpoint: to say “an ASD” while speaking of an autistic person is like saying “a disorder.” An “ASD person” signifies a “disordered person” and “person with ASD” signifies a “person with a disorder.” The respect for the dignity of people, as well as respect for language and grammar, justify these recommendations.

-“Levels” of autism favor discrimination. It is preferable to speak of their capacities, talents of the person as well as their challenges and difficulties.

Guide by Marie Lauzon, Lucila Guerrero and Antoine Ouellette for Aut’Créatifs, a community of #ActuallyAutistic in favor of  positivie recognition of autism mind.

Translate by Hunter McLean.

Français: Raconter l’autisme autrement