Electromagnetic waves and autism, a suspected link?


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Autism Spectrum Disorder (ASD) has increased dramatically in Western societies in recent decades. About 0.8 per 1,000 children aged 1 to 17 were diagnosed with autism in Quebec between 2000 and 2001, and 17 per 1,000 in 2019, according to Health Canada.

This increase is largely due to changes in the definition of what constitutes the autism spectrum itself: the evolution of this definition since the 1990s has been based on a better understanding of these disorders. Because of this, many cases in the past may have slipped under the radar by being labeled as “intellectual disability.”

However, the fact that they are better diagnosed does not prevent the causes of ASD from being poorly understood. Among the suspected risk factors: certain genetic mutations, metabolic imbalances, exposure to heavy metals and environmental toxins. Can electromagnetic fields be added to the list?

Mainly thermal effects

Among the thousands of studies conducted over the past 30 years on cells, animals or humans, the only effect of radio waves and electromagnetic fields is the possible heating of tissues. For example, a 2021 French-Italian study concluded that as people age and electromagnetic fields are high, they feel skin tissue heating more. Older people have thinner skin and less blood flow.

Given current standards for electromagnetic fields, tissue heating is too low to damage cells. However, a review of research published in 2019 raises the possibility that it has biological effects unrelated to tissue heating. According to the authors, about 70% of studies using frequencies from 6 to 100 GHz—Wi-Fi uses frequencies between 2 and 5 GHz, while 5G technology varies between 0.5 and 30 GHz—even on living things “do not could detect “heat” effects. organisms regardless of power density (58% of those conducted on animals).

However, the two authors note that most of these studies do not meet the quality standards necessary to produce satisfactory results. This means that more research will be needed to determine if and how 5G affects human tissue.

Cognitive effects?

One such study, published in 2017, sought to investigate whether intensive cell phone use affects cognitive function. The researchers divided about 60 female students between the ages of 18 and 25 into two groups based on how much they used their phones: 30 minutes a day or less in the past five years or 90 minutes a day or more. They concluded that the second group was more associated with attention difficulties. However, this study has several limitations: the small number of people observed, the fact that it was based on students’ self-reported use time, and the fact that there may be several indirect effects associated with phone laptop use. , without electromagnetic fields being responsible for the mentioned changes.

Another review of the scientific literature, published in 2018, points in the opposite direction. After reviewing 43 studies looking at EMF exposure and cognitive function, the authors concluded that there was no strong association.

and autism?

Under these conditions, Evidence linking autism is difficult to find. An internet search brings up numerous articles and studies linking exposure to electromagnetic radiation. The problem is that many of these publications come from groups or researchers who advocate for reducing exposure to waves, and this overshadows their writing.

These publications have been discarded, but there are still some studies investigating the effect of waves on the development of autism.

In 2004, one of them suggested that fetal or neonatal radiation may be associated with an increased incidence of autism. The hypothesis was reanalyzed in a 2009 study in the context of an increase in autism diagnoses, but due to the limited amount of data available, the authors were unable to substantiate the claim.

At the same time, in the 2000s, the weight of environmental factors in the development of autism was questioned. In an American study published in 2011, the authors suggested that genetics accounts for less than half of the risk of autistic disorder, and less than 90% as previously suggested.

If electromagnetic fields do indeed play a role as one of these environmental factors, what might it be? These areas are said to have the ability to alter the epigenome—that is, all the epigenetic modifications of a cell—during the first trimester of pregnancy, which could lead to autism in babies who carry the genetic abnormalities, three researchers hypothesized in a paper published in 2013. .

This hypothesis is gaining momentum, and in 2014 researchers from Bahrain suggested a causal link between exposure to very low-frequency electromagnetic fields in mice and autism. However, if autism is already difficult to diagnose in humans, one can imagine that the way to diagnose it in mice is still being debated.

It is in this spirit that an article was published in 2017 Child Development experts who hypothesize such a connection are quickly condemned by experts who call it “pseudoscience”. The authors have been criticized for relying on poor quality data and extrapolating inappropriately from rodent data. A few months later, the journal would publish a critical commentary denouncing the original article.

Judgment

Very low frequency electromagnetic fields may have a biological effect of increasing skin temperature, but there is no evidence that they can cause cognitive impairment, let alone the development of autistic disorders.

Photo: NCI

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