Electromagnetic waves are everywhere. They’re the reason you can hear music when you turn on the radio, use wi-fi, find your way using satellite navigation, and make calls on a mobile phone.
They are a form of electromagnetic radiation and sit at the weaker end of the spectrum , meaning they have the lowest energy and the longest wavelength.
But because very high-energy forms of electromagnetic radiation – such as x-rays – can cause cancer, there has long been concern that radio waves could also harm human health.
With the explosion of mobile phone use over the past two decades, there has been particular concern over whether holding these devices to your ear could increase your risk of brain cancer.
In 2019, the World Health Organization (WHO) commissioned 13 reviews on the health effects of electromagnetic waves.
A new study, released today has analysed the findings of these reviews. It’s found no evidence that electromagnetic waves emitted by mobile phones cause cancer in the brain, head or neck. Let’s take a look at what else they found.
Did the fear of cancer have any basis?
Anxiety about the potential health effects of low-energy radiation has its roots in the Cold War.
This was the period when new technologies such as microwave ovens and televisions were first widely adopted and entered many homes.
Microwaves, the electromagnetic radiation we use to heat food, have somewhat higher energy than the waves emitted by mobile phones, but are still low .
Over time, the evidence that emerged showed there are no clear, consistent effects on health for humans exposed to lower-energy electromagnetic radiation.
But there were still legitimate safety concerns. For example, microwaves can still make things very hot. These concerns shaped the standards for consumer electronics , which govern and limit how much radiation they can emit. These standards ensure their safety, based on the best evidence available.
Of course, high-energy electromagnetic radiation was known to be very dangerous, and capable of causing cancers such as leukaemias .
Coupled with sensational Cold War events – such as the Soviets’ suspected intentional use of “electromagnetic signals” to target staff at the US embassy in Moscow with microwave radiation, and an ambassador developing leukaemia – these dangers likely shaped public opinion and led to some fear about any kind of radiation, including low-energy radiation.
And, as our exposure to electronics emitting low-energy radiation has dramatically increased in the intervening decades, the concern about its effect on health has remained widespread and perhaps even grown.
What the new study looked at
The 13 reviews the WHO commissioned in 2019 aimed to understand what we already know and what we still need to find out about any health effects of electromagnetic waves.
Teams of scientists looked through the published scientific evidence available for a particular health concern and wrote a report summarising not only the findings but also the quality, or strength, of the available data. Reviews were completed for a number of different health concerns, including fertility, symptoms such as headaches or tinnitus, and cancer.
But the WHO has not yet completed its analysis of the commissioned reviews.
So two authors of the review on brain cancer have summarised their own results, and those of the other reviews. This new research gives us an insight into the WHO’s expected findings.
What the new study found
The authors’ own review focused on brain cancer and mobile phone use . In it, they analysed 63 different studies published between 1994 and 2022, and found no association between mobile phone use and brain cancer, or cancers of the head or neck.
It also didn’t matter how much someone used their mobile phone, or whether they had been using it over long periods (ten or more years).
The same review also found there was no evidence linking radio or television transmission and leukaemia in children (another persistent fear).
Most evidence is limited or low-quality
The other reviews of observational studies in humans similarly found no evidence that exposure to mobile phones – and other devices that emit electromagnetic waves – affected health. But a key finding was that, for many health effects, the quantity or quality of the evidence was really too poor to make firm conclusions.
This is because determining the precise effects of anything on humans is complicated. Many different factors affect health outcomes , including diet, exercise, genetics and socioeconomic considerations.
Fortunately, the evidence for brain cancer was given the highest quality rating possible for an observational study (meaning a study in which scientists only observe the effects of electromagnetic waves on people, without controlling exposure).
The authors also cut to the heart of the matter for brain cancer, noting: “If there was an increased risk of brain cancer from mobile phone exposures, increases in the incidence would be expected.”
In Australia, rates of all types of brain cancer have remained steady since the 1980s, well before widespread and regular mobile phone use.
The takeaway
As the authors of the summary report state: “No science can ‘prove’ the absence of any risk.”
One goal of the WHO reviews was to understand what future research is still needed so exposure guidelines can be kept up to date as technology develops.
But the takeaway should be that no clear association has been found between mobile phone use and any type of brain, head or neck cancer.
This will hopefully reassure you that current exposure limits are likely safe.
