increased risks of neurodisorders?

Threat in our cupboards? Exposure to some very common household chemicals could increase the risk of neurological diseases, such as multiple sclerosis, or neurodevelopmental disorders (NDDs), such as autism or ADHD (attention deficit disorder), which is on the rise constant over the last decade. This is what emerges from an American study, carried out by the Faculty of Medicine of Case Western Reserve, published in Nature Neuroscience in March 2024.

What products?

Certain environmental chemicals are affected, divided into two classes. First of all, organophosphorus flame retardants (RFOP), fire-resistant, used in the manufacture of dyes, varnishes, textiles, resins, but also quaternary ammonium compounds (QAC), “ubiquitous in many personal care products, such as shampoos and disinfectants”, according to the authors of the study.

They damage vital brain cells called oligodendrocytes. Initiated at the fetal stage and developing throughout life, their function is to manufacture and maintain the myelin sheath which protects nerve cells and accelerates the transmission of nerve impulses.

300 cytotoxic products out of 1,800

During testing, these cells were exposed to 1,823 different chemicals. Conclusion: if more than 80% had no effect on the development of oligodendrocytes, 292 were found to be “cytotoxic” (i.e. toxic to cells), with “adverse effects on neurodevelopment”. Although the study uses a mouse model and laboratory cultures, it could have profound implications for human health. Indeed, the researchers then assessed the levels of organophosphates in children aged three to eleven years old by analyzing their urine. As a result, those with the highest levels were two to six times more likely to have special educational needs or motor dysfunction.

Less harmful alternatives

Objective of this study? Alert in order to reduce exposure to these products for the most vulnerable groups (pregnant women, children and people with chronic illnesses), even though their consumption has exploded since the Covid pandemic, particularly with regard to disinfectants ( QAC). Alternatives? Caprylic and citric acids, white vinegar, black soap, baking soda and other active ingredients such as hydrogen peroxide and alcohol.

Exercise caution!

Dr. Sarkar, assistant professor of environmental medicine and neuroscience at the University of Rochester medical center, cited by the media ma-clinique.fr, nevertheless recommends “exercise caution when interpreting results”, while agreeing that they “could serve as a basis for future studies”. The authors of the study also emphasize, “the need for further examination of the impacts of these compounds on human health”.

Worn by many teams

According to Etienne Pot, interministerial delegate to TND, “the study of environmental factors, which can contribute, in utero, to the appearance of neurodevelopmental disorders, is carried out by numerous teams around the world”. “We know that exposure to major toxic substances during pregnancy can be a risk factor, which is why we included it in the screening booklet intended for 0-7 year olds” (Autism, TND: systematic identification in the health record).

Multifactorial causes

“As the authors point out, we still cannot conclude anything with certainty, except to reaffirm that autism and other TNDs are indeed present from birth and that the causes are probably multifactorial, including a genetic part,” he adds. Research continues and this is also the interest of the Marianne Cohort, launched in France in 2023 (Marianne: a giant cohort to understand the origin of TND). “The most important thing is to remember that parents and their way of behaving during the first months of life have nothing to do with the appearance of TND,” concludes Etienne Pot.

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