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14/05/2008 - Using phones in pregnancy and child behavioural problems?
Background:The World Health Organization has previously emphasized the
need for research into the possible effects of radiofrequency fields in
children. Leading researchers from the United States and Denmark have just
examined the association between prenatal and postnatal exposure to cell phones
and behavioral problems in young children.
Results: The results are very surprising, with an 80% increase in behavioural
problems for those mothers who had used phones whilst pregnant (CI: 1.45-2.23).
The study is the first to investigate this issue and as such the results
have to interpreted with some caution.
There are a number of possible confounding factors for this association, some
of which (gender, socioeconomic class, family history of mental illness,
smoking) were considered. Taking these factors into account actually made the
results marginally stronger and more significant than those shown above, though
there may be unconsidered confounders that have a significant effect.
This is a strong statistical finding, that gives good reason for concern
despite there being no known obvious mechanism for this association.
The paper discusses RF exposures to the unborn child but, realistically,
these are likely to be vanishingly small from handset use by the mother. If
the mother kept their handset in a waist belt pouch, then that could cause
significant exposure, but it is mainly men who carry their handsets in trouser
belt holsters. 85% of the mothers usually carried their phones in a handbag or
case and 82% did not use a personal hands-free kit or earpiece so, when in use,
the handset would be well away from the foetus.
As well as pulsed microwaves, GSM phones emit strong 217Hz pulsed low-frequency
magnetic fields from the surges of current from the battery. These can be as
high as 8 microtesla 1 cm from the handset (i.e. next to the user's head), but
fall off fairly quickly (within about 30 cm to very low levels). So these are
only likely to affect the foetus is the phone is carried on standby on or near
the waist (phone regularly emit these strong pulses when on standby). To put
these levels into context, a doubling in the incidence of childhood leukaemia is
associated with a 50 Hz field of only 0.4 microtesla. The induced currents in
the body increase with frequency, so at 217 Hz the 8 microtesla field mentioned
above would be equivalent to 35 microtesla at 50 Hz. Even so, the handset would
have to be carried close to the unborn child (e.g. on, or close to, the waist).
Also, magnetic fields from electric trains and other sources would be a large
One possibility is that the EMF exposure of the mother is causing alterations
to the development of the foetus, either through direct bio-chemical changes or
through epigenetic changes. It is clear that epigenetic changes in a mother can
be passed on to their unborn child, especially those due to stress. It is
possible that either mobile phone use directly (through EMFs) or indirectly
(through a more hectic and stressed maternal lifestyle) have been passed on to
the children and abnormal hormone levels have caused the reported behavioural
There is scientific support that maternal prenatal exposure can have an
effect on the development of the unborn child (Yehuda 2005,
Brand 2006) and also
in animal studies (Waterland 2003, Carere 2005), and something along these lines seems to be the most likely
explanation if the association is found to be causal.
Some further insights on this paper, including comments from one of the study
authors, can be found on Louis Slesin's Microwave News site.