Electromagnetic Fields 2015 Update
4. Can mobile phones or base stations trigger headaches or other health effects?
- 4.1 Have headaches and other symptoms been linked to mobile phones?
- 4.2 Can mobile phones affect the brain?
- 4.3 Have effects from RF fields of mobile phones on reproduction and development been reported?
- 4.4 Are children more vulnerable to possible effects of mobile phones?
4.1 Have headaches and other symptoms been linked to mobile phones?
Mobile phone base station
Some people attribute non-specific health symptoms such as
headache, nausea, dizziness, fatigue and skin irritation to
their exposure to electromagnetic
fields. Such complaints have raised concern that
certain individuals may be more sensitive than others to EMF.
These self-reported symptoms have been named
hypersensitivity (EHS). The reported symptoms can
sometimes be severe enough to cause serious impairments to a
person’s wellbeing. While their health concerns are valid,
studies conducted since the previous Opinion (about 15 reviewed)
adds weight to the existing body of evidence that exposure to RF
does not trigger symptoms, at least in the short-term. While
additional observational studies are required to assess whether
longer-term exposure could be associated with symptoms, the
evidence to date weighs against a causal effect.
For symptoms triggered by short-term exposure to RF fields
(measured in minutes to hours), the consistent results from
multiple double-blind experiments lead to a strong overall
weight of evidence that RF fields do not cause such effects. For
symptoms associated with longer-term exposures (days to months),
the evidence from observational studies is broadly consistent
but has gaps, most notably in terms of the objective monitoring
of exposure. Current evidence weighs towards an absence of
effects due to RF fields exposure.
Even when a participant’s self-report of exposure to RF is
accurate, it is still difficult to differentiate whether any
association with symptoms is the result of RF exposure per se or
whether the association is the result of a ‘nocebo’ effect (a
negative placebo effect),
whereby the participant’s belief that they are being exposed is
sufficient to trigger their symptoms.
Subjects who know they are exposed to some RF fields, e.g.
because they use a mobile phone or live near a transmission
tower, tend to report more symptoms, whereas double-blind
provocations studies where subjects do not know whether they are
exposed to RF fields or not do not find a consistent link
between radio frequency fields and symptoms.
Actually, there is no scientific evidence that humans - either
so-called sensitive groups or healthy
control groups - can
perceive radio frequency fields better than would be expected by
4.2 Can mobile phones affect the brain?
Because mobile phones come in contact with the head, there
have been concerns they could affect the brain.
Studies on possible effects of RF exposure on brain function
in humans (such as sleep,
flow and oxygenation changes) have given mixed results.
The conducted studies are difficult to compare with one another,
and so the observed effects were not sufficiently replicated.
There are some studies indicating that effects might vary with
age and gender; it is not known whether subjects with
pre-existing medical conditions may be affected differently.
Most of the recent studies have confirmed an effect of RF
exposure on electro encephalograms (EEG). There have also been
effects found on sleep EEGs but there is not yet any conclusive
evidence. Several of the recent studies addressing RF effects on
spatial learning, memory, and behaviour suggest an effect at low
field levels but there remain significant questions regarding
the experimental protocols. No conclusive evidence can be drawn
Experimentally, a number of different end-points have been
studied in both mice and rats. Globally these observations are
inconsistent and appear mostly at levels well above guidelines
values. One of those
endpoints is the potential
impairment of the blood-brain barrier. Recent studies do not
show that exposure to RF has any effect, several of the studies
are done in such a way that their relevance for
risk assessment is
neurological disorders and
functions, locomotion or an increased risk of Alzheimer's, there
is no evidence that RF exposure from mobile phone use have a
4.3 Have effects from RF fields of mobile phones on reproduction and development been reported?
Numerous large and well-conducted studies have investigated
potential effects of RF fields on development of animals,
including mammals and birds and clearly show that RF fields can
cause birth defects when
the exposure is well above safety guidelines and therefore high
enough to significantly raise temperatures in tissue. No
consistent evidence of effects has been found at exposure levels
that do not cause relevant heating of tissues.
No significant effects were seen from almost continuous,
lifetime exposure of mice over four generations. More recent
studies have not shown increased risks of
disease or reproductive effect related to RF exposure; effects
on foetuses from mothers’
mobile phone use during pregnancy are judged not plausible due
to the low level of exposure. The data available provide no
clear evidence of consistent adverse effects on human semen
The previous SCENIHR Opinion (2009) concluded that there were
no adverse effects on reproduction and development from RF
fields at non-thermal exposure levels. The inclusion of more
recent human and animal data does not change this
There are still no substantiated indications of any other
4.4 Are children more vulnerable to possible effects of mobile phones?
With so many children using mobile phones, there is concern
about how radio signals may affect them. Some people worry that
children could be more
vulnerable than adults
because their nervous
systems are still developing, their brain tissue is more
conductive, their heads might absorb more energy from mobile
phones and children using mobile phones will have a greater
lifetime exposure than people who were adults when they began
using them. Children can also be exposed through other sources,
such as baby monitors. Few studies have addressed the possible
effects of radio signals on children, and extrapolating from
adult studies remains problematic. Overall, current evidence
does not demonstrate that children might be more vulnerable to
RF EMF, however, due to physiologic reasons they tend to be
higher exposed from mobile phones than adults.