Electromagnetic waves and autism, a dubious link?
The fears surrounding electromagnetic waves are numerous and sometimes surprising. One of them: an increase in autism spectrum disorders. TheRumor Detector wondered where the concern came from.
Autism Spectrum Disorders (ASD) have increased dramatically in recent decades in Western societies. In Quebec, about 0.8 out of 1,000 children aged 1 to 17 had an autism diagnosis in 2000-2001, compared to 17 out of 1,000 in 2019, according to Health Canada.
This increase is due in large part to changes to the definition itself of what the autism spectrum is: the evolution of this definition since the 1990s is based on a better understanding of these troubles. For this reason, many cases in the past may have passed under the radar, being referred to as “intellectual disabilities”.
But the fact of better diagnosing them does not prevent the causes of ASD from remaining poorly understood. Among the suspected risk factors: certain genetic mutations, metabolic imbalances, exposure to heavy metals and environmental toxins. Could electromagnetic fields be added to the list?
Especially thermal effects
Among the thousands of studies carried out over the past 30 years on cells, animals or humans, the only impact of radio waves and electromagnetic fields that has been quantified is a possible heating of tissues. In 2021, a Franco-Italian study, for example, concluded that people feel the warming of skin tissues more as they age, and when electromagnetic fields are high. However, older people tend to have thinner skin and reduced blood flow.
Given current standards for electromagnetic fields, tissue heating is too low to damage cells. However, a review of the research, published in 2019, raises the possibility of biological effects that are not related to tissue heating. According to the authors, about 70% of studies using frequencies from 6 to 100GHz – Wi-Fi uses frequencies between 2 and 5GHz while 5G technology varies between 0.5 and 30GHz – would have detected such effects “ non-thermal” on living organisms, regardless of the power density (58% of those conducted on animals).
The two authors note, however, that the majority of these studies do not respect the quality standards necessary to draw satisfactory conclusions. Which means more research will be needed to determine if and how 5G can affect human tissue.
Cognitive effects?
One of these studies, published in 2017, wanted to examine whether intensive use of a mobile phone could affect cognitive functions. The researchers separated around 60 female students aged 18 to 25 into two groups, depending on how much time they reported using their phones: 30 minutes or less a day for the past five years, or 90 minutes and more a day. . They concluded that the second group was associated with greater attention difficulties. However, this study has several limitations: the small number of people observed, the fact that it is based on the estimation of the time of use by the students themselves, and that several indirect effects linked to the use of a telephone laptop may be involved, without electromagnetic fields being responsible for the noted changes.
The conclusions of another review of the scientific literature published in 2018 go in the opposite direction. After reviewing 43 studies looking at EMF exposure and cognitive function, the authors conclude that there is no strong link.
And autism?
In these conditions, it is difficult to find evidence that would make a link with autism. A search on the Internet brings up numerous articles and studies claiming to link exposure to EMF radiation. The problem is that many of these publications come from groups or researchers advocating a reduction in exposure to the waves, which casts a shadow on their writings.
Aside from these publications, there are still a few studies that have explored the impact of waves on the development of autism.
In 2004, one of them suggested that fetal or neonatal exposure to radiation could be associated with an increased incidence of autism. The hypothesis was again analyzed in 2009, in a study carried out in the context of the increase in autism diagnoses, but the authors were unable to substantiate the claim, due to the limited amount of data available.  ;
At the same time, during the 2000s, the weight of environmental factors in the development of autism was questioned. In an American study published in 2011, the authors suggest that genetics represents less than half the risk of autism disorders – and not 90% as previously suggested.
If electromagnetic fields really play a role as one of these environmental factors, what could it be? These fields are said to have the ability to modify the epigenome, i.e. all of the epigenetic modifications of a cell, during the first trimester of pregnancy, which could lead to autism in infants carrying genetic abnormalities, speculate three researchers in an article published in 2013.
The hypothesis is gaining ground and in 2014, researchers from Bahrain suggested a causality between exposure to very low frequency electromagnetic fields and autism… in mice. However, if it is already difficult to diagnose autism in humans, one can imagine that the way to diagnose it in mice is still debated.
It is in this spirit that in 2017, an article published in Child Development which put forward the hypothesis of such a link was quickly denounced by experts who went so far as to qualify it as “ pseudoscience ”. The authors are criticized for inappropriately extrapolating from rodent data, in addition to relying on poor quality data. The journal will publish a critical comment a few months later denouncing the original article.
Verdict
Very low frequency electromagnetic fields may have the biological effect of increasing skin temperature, but there is no evidence that they can promote disorders cognitive, let alone the development of autism disorders.
