It’s scary to hear that cellphones — devices that most of us have with us all the time — have been linked to cancer by a government study.
But
despite any headlines you may have seen, there’s still not enough
information or evidence for the average person to be concerned by these
findings.
“I’m
not going to stop using my mobile phone in the light of this,” Kevin
McConway, emeritus professor of applied statistics at The Open
University, said in a statement to the Australian and UK Science Media Centre.
Here’s why you shouldn’t panic
The latest results that we have access to are very preliminary findings from a peer-reviewed study
conducted by the US National Toxicology Program (NTP). That experiment
looked at the effects of cell phone radiation on a number of rats, and
we won’t see the full findings until at least later on this year.
So
far, the released NTP data show a very weak link between excessive cell
phone radiation exposure and the risk of developing some cancers.
Specifically, male rats that were exposed to full-body doses of
radiation for nine hours a day — from before the time they were born
until they were just over two years old — were slightly more likely to
develop brain and heart cancers than rats not exposed to that radiation.
It’s
an interesting finding, and one that could explain a mechanism by which
radiation like that from cell phones could potentially cause cancer.
That potential causal mechanism was enough to convince some involved
with the study to release that information to the website Microwave News, which wrote about the results before NTP released the data.
lab rats
SMercury98 via Flickr
If
these results were to directly apply to humans, that would be scary.
And if cell phone use increased human cancer rates even two or three
percent (approximately the increased risk seen in rats), that would be a
vast increase in the number of cancer cases across the globe.
But
that’s not what the data released so far shows, and extensive studies
of human cell phone use certainly don’t show cancer rates increasing in
that way.
So far it’s a stretch to apply this study to humans
First
and foremost, rats are not humans, and many of the ways we test things
on animals mean we find results there that don’t end up translating to
humans.
But the differences between the rats that did develop tumors in the experiment and the rats that did not leave us with a lot of questions.
Groups
of rats were exposed to radiation at three different levels. These
radiation levels were much higher than the levels most people are
exposed to. Also, the rats were exposed to this radiation from before
they were born to the end of the study for a full nine hours a day — not
exactly replicating real-world human cellphone usage.
“I
understand from information in the report that the lowest radiation
levels used were somewhere around the safety limits imposed on mobile
phone manufacturers, for the radiation when one is actually using the
phone,” said McConway. “It’s certainly not yet obvious how these
high-dose results in rats might tell us anything about normal levels of
human mobile phone use.”
Male
rats exposed to radiation were more likely to develop tumors, but
exposed rats were also more likely to survive the two-year test period
than rats who were not exposed.
This
“is counter intuitive given that the increased tumour rates normally
lead to reduced lifespan,” Rodney Croft, Director of the Australian
Centre for Electromagnetic Bioeffects Research, told the Science Media
Centre.
cancer cell
GE
A cancer cell.
Strangely,
while an increased cancer risk was found in male rats, there was no
increased cancer risk for female rats. And strangely, none of the rats
in the control groups developed these brain tumors, which is not normal —
some cancers would be expected in the control groups, too.
“The
NTP study will thus need to be fully evaluated once further details
become available, and considered within the context of RF emissions
science as a whole,” said Croft. “At present though, and particularly
given a range of uncertainties regarding its results, the NTP report
does not provide reason to move from the current scientific consensus
that mobile phone-like exposure does not impact health.”
The
study gives us interesting information and definitely contributes to
the discussion of the potential health impacts of cellphones. But for
now, these results aren’t quite as “explosive” as they’ve been described.
Scientists
have previously said there’s a possible chance that cell phone use
could cause cancer (like almost everything ever studied, pickled
vegetables and coffee included), but that so far, most studies haven’t shown increased cancer incidence in humans that we can directly say comes from cell phone use.
So
far, these results seem to confirm that conclusion — there’s a
mechanism by which cell phone use might cause cancer, but we don’t
actually know that’s it’s doing so in humans.
Still,
some scientists think the risk is real. Swedish oncologist Lennart
Hardell tells Tech Insider that these results confirm previous research
that he says shows an increased risk of brain cancer from cordless and
mobile phone use. That’s not the consensus and so far, other researchers like Dr. Timothy Moynihan at the Mayo Clinic have concluded
that “there’s no convincing evidence that cellphone use increases the
risk of cancer.” But any new data that sheds light on the issue is
interesting.
“There
has been much previous research on this topic, some of which has found
no evidence of any risk, and some of which has found limited evidence of
a small risk with heavy phone use. I don’t think that these NTP results
have moved us on from that yet,” said McConway.
