The effects of EMF on the endocrine system
in children and adolescents
Sangün
Ö, Dündar B, Çömlekçi S, Büyükgebiz A. The Effects of Electromagnetic
Field on the Endocrine System in Children and Adolescents. Pediatr
Endocrinol Rev. 2015 Dec;13(2):531-45.
Abstract
Children
are exposed to various kind of non-ionizing radiation in their daily
life involuntarily. The potential sensitivity of developing organism to
the effects of radiofrequency (RF) signals, the higher estimated
specific absorption rate (SAR) values of children and greater lifetime
cumulative risk raised the scientific interest for children's
vulnerability to electromagnetic fields (EMFs). In modern societies,
children are being exposed to EMFs in very early ages. There are many
researches in scientific literature investigating the alterations of
biological parameters in living organisms after EMFs. Although the
international guidelines did not report definite, convincing data about
the causality, there are unignorable amount of studies indicating the
increased risk of cancer, hematologic effects and cognitive impairment.
Although they are less in amount; growing number of studies reveal the
impacts on metabolism and endocrine function. Reproductive system and
growth look like the most challenging fields. However there are also
some concerns on detrimental effects of EMFs on thyroid functions,
adrenal hormones, glucose homeostasis and melatonin levels. It is not
easy to conduct a study investigating the effects of EMFs on a fetus or
child due to ethical issues. Hence, the studies are usually performed on
virtual models or animals. Although the results are conflicting and
cannot be totally matched with humans; there is growing evidence to
distress us about the threats of EMF on children.
http://1.usa.gov/1QhY253
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Does exposure to environmental radiofrequency electromagnetic fields
cause cognitive and behavioral effects in 10-year-old boys?
Calvente,
I., Pérez-Lobato, R., Núñez, M.-I., Ramos, R., Guxens, M., Villalba,
J., Olea, N. and Fernández, M. F. (2016), Does exposure to environmental
radiofrequency electromagnetic fields cause cognitive and behavioral
effects in 10-year-old boys?. Bioelectromagnetics, 37: 25–36.
doi: 10.1002/bem.21951.
Abstract
The
relationship between exposure to electromagnetic fields from
non-ionizing radiation and adverse human health effects remains
controversial. We aimed to explore the association of environmental
radiofrequency-electromagnetic fields (RF-EMFs) exposure with
neurobehavioral function of children.
A subsample of 123 boys
belonging to the Environment and Childhood cohort from Granada (Spain),
recruited at birth from 2000 through 2002, were evaluated at the age of
9–11 years. Spot electric field measurements within the 100 kHz to 6 GHz
frequency range, expressed as both root mean-square (SRMS) and maximum power density (SMAX) magnitudes, were performed in the immediate surrounds of children's
dwellings. Neurocognitive and behavioral functions were assessed with a
comprehensive battery of tests. Multivariate linear and logistic
regression models were used, adjusting for potential confounders.
All measurements were lower than reference guideline limits, with median SRMS and SMAX values of 285.94 and 2759.68 μW/m2,
respectively. Most of the cognitive and behavioral parameters did not
show any effect, but children living in higher RF exposure areas (above
median SRMS levels)
had lower scores for verbal expression/ comprehension and higher scores
for internalizing and total problems, and obsessive-compulsive and
post-traumatic stress disorders, in comparison to those living in areas
with lower exposure. These associations were stronger when SMAX values were considered.
Although
some of our results may suggest that low-level environmental RF-EMF
exposure has a negative impact on cognitive and/or behavior development
in children; given limitations in the study design and that the majority
of neurobehavioral functioning tasks were not affected, definitive
conclusions cannot be drawn.
http://onlinelibrary.wiley.com/doi/10.1002/bem.21951/abstract
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November 19, 2015
Two recently published studies on adolescents report harmful effects of mobile phone use. A cross-sectional study found that adolescents who were awakened by a mobile phone at least once a month during the night were more likely to report tiredness, rapid exhaustibility, headache and physical ill-being. A prospective cohort study found that greater wireless radiation exposure predicted lower memory test performance.
Symptoms and cognitive functions in adolescents
in relation to mobile phone use during night
Schoeni
A, Roser K, Röösli M. Symptoms and Cognitive Functions in Adolescents
in Relation to Mobile Phone Use during Night. PLoS One. 2015 Jul
29;10(7):e0133528. doi: 10.1371/journal.pone.0133528. eCollection 2015.
Abstract
Many
adolescents tend to leave their mobile phones turned on during night,
accepting that they may be awakened by an incoming text message or call.
Using self-reported and objective operator recorded mobile phone use
data, we thus aimed to analyze how being awakened during night by mobile
phone affects adolescents' perceived health and cognitive functions.
In
this cross-sectional study, 439 adolescents completed questionnaires
about their mobile phone use during night, health related quality of
life and possible confounding factors. Standardized computerized
cognitive tests were performed to assess memory and concentration
capacity. Objective operator recorded mobile phone use data was further
collected for 233 study participants. Data were analyzed by
multivariable regression models adjusted for relevant confounders
including amount of mobile phone use.
For adolescents reporting to be
awakened by a mobile phone during night at least once a month the odds
ratio for daytime tiredness and rapid exhaustibility were 1.86 (95% CI:
1.02-3.39) and 2.28 (95% CI: 0.97-5.34), respectively. Similar results
were found when analyzing objective operator recorded mobile phone use
data (tiredness: 1.63, 95% CI: 0.94-2.82 and rapid exhaustibility: 2.32,
95% CI: 1.01-5.36). The cognitive tests on memory and concentration
capacity were not related to mobile phone use during night. Overall,
being awakened during night by mobile phone was associated with an
increase in health symptom reports such as tiredness, rapid
exhaustibility, headache and physical ill-being, but not with memory and
concentration capacity.
Prevention strategies should focus on helping
adolescents set limits for their accessibility by mobile phone,
especially during night.
Conclusion
Among Swiss adolescents, we have
observed that nocturnal mobile phone use was associated with an increase
in health symptom reports such as tiredness, rapid exhaustibility,
headache and physical ill-being, but not with memory and concentration
capacity. More studies to investigate these associations are necessary
and education in sleep behaviour may be inevitable since the mobile
phone is now the most familiar lifestyle factor for adolescents.
Public
Health prevention strategies should focus on helping adolescents set
limits for their accessibility by mobile phone, especially during night.
Open Access Paper: http://1.usa.gov/1NeP2lJ
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Memory
performance, wireless communication and exposure to radiofrequency
electromagnetic fields: A prospective cohort study in adolescents
Schoeni A, Roser K, Röösli M. Memory performance, wireless communication and exposure to
radiofrequency electromagnetic fields: A prospective cohort study in
adolescents. Environ Int. 2015 Oct 13;85:343-351. doi: 10.1016/j.envint.2015.09.025. [Epub ahead of print]
Abstract
BACKGROUND:
The aim of this study is to investigate whether memory performance in
adolescents is affected by radiofrequency electromagnetic fields
(RF-EMF) from wireless device use or by the wireless device use itself
due to non-radiation related factors in that context.
METHODS: We
conducted a prospective cohort study with 439 adolescents. Verbal and
figural memory tasks at baseline and after one year were completed using
a standardized, computerized cognitive test battery. Use of wireless
devices was inquired by questionnaire and operator recorded mobile phone
use data was obtained for a subgroup of 234 adolescents. RF-EMF dose
measures considering various factors affecting RF-EMF exposure were
computed for the brain and the whole body. Data were analysed using a
longitudinal approach, to investigate whether cumulative exposure over
one year was related to changes in memory performance. All analyses were
adjusted for relevant confounders.
RESULTS: The kappa
coefficients between cumulative mobile phone call duration and RF-EMF
brain and whole body dose were 0.62 and 0.67, respectively for the whole
sample and 0.48 and 0.28, respectively for the sample with operator
data. In linear exposure-response models an interquartile increase in
cumulative operator recorded mobile phone call duration was associated
with a decrease in figural memory performance score by -0.15 (95% CI:
-0.33, 0.03) units. For cumulative RF-EMF brain and whole body dose
corresponding decreases in figural memory scores were -0.26 (95% CI:
-0.42, -0.10) and -0.40 (95% CI: -0.79, -0.01), respectively. No
exposure-response associations were observed for sending text messages
and duration of gaming, which produces tiny RF-EMF emissions.
CONCLUSIONS:
A change in memory performance over one year was negatively associated
with cumulative duration of wireless phone use and more strongly with
RF-EMF dose. This may indicate that RF-EMF exposure affects memory
performance.
http://1.usa.gov/1M6BCHW
Excerpts
...
From a public health point of view potential effects of chronic
exposure are more relevant, which needs to be investigated with
epidemiological studies. So far there has only been one community-based
epidemiological study investigating effects of mobile phone use on
adolescents' memory. Abramson et al. (2009) showed in a cross-sectional
analysis of 317 seventh grade students from Australia that mobile phone
use was associated with faster and less accurate response on a number of
tasks involving the memory. Since similar associations were found in
relation to the number of SMS (short text messages), which produces
negligible RF-EMF exposure, they speculated that these behaviours may
have been learned through the frequent use of a mobile phone and may not
be the consequence of mobile phone radiation. In a follow-up
investigation one year later, in 236 of these students, an increase in
mobile phone use was associated with a reduction in response time in one
out of three tests involving the memory (Thomas et al., 2010). This
study relied on self-reported mobile phone use only, which has been
shown to be inaccurate. Adolescents tend to substantially overestimate
their amount of mobile phone use (Aydin et al., 2011; Inyang et al.,
2009).
Regular mobile phone use may affect adolescents in various
ways. Thus, the main challenge for research consists in differentiating
between RF-EMF radiation effects and other non-RF-EMF related effects
from mobile phone use. For instance, frequent texting or gaming on a
mobile phone may facilitate cognitive processes (Abramson et al., 2009).
It was also observed, that calling and sending texts during night was
associated with poor perceived health symptoms such as tiredness, rapid
exhaustibility, headache and physical ill-being (Schoeni et al., 2015;
Van den Bulck, 2007). Other studies showed that frequent mobile phone
use was associated with anxiety (Jenaro et al., 2007), unhealthy
lifestyle (Ezoe et al., 2009), depression (Yen et al., 2009) and
psychological distress (Beranuy et al., 2009). Thus, to address RF-EMF
effects of wireless communication devices, the development of a RF-EMF
dose measure, which incorporates all exposure relevant factors, is
inevitable.
Memory performance was assessed with a
standardized, computerized cognitive test battery (IST,
Intelligenz-Struktur-Test 2000R (Liepmann et al., 2006)). Verbal and
figural memory was measured with the subtest of the IST. In the verbal
memory task, word groups have to be memorized in one minute time. After 1
min the study participants give an account of the word groups that have
been memorized. In total 10 points can be achieved by remembering the
correct word groups. In the figural memory task, pairwise symbols have
to be memorized in one minute time. After 1 min one part of the pairwise
symbols is shown and the matching part has to be found. A total of 13
points can be achieved. For both the verbal and figural tests, 2 min is
given to complete the test. Memory performance is considered as the
right number of remembered word groups or symbols, respectively. For the
statistical analyses of verbal and figural memory the continuous test
score values
were used as outcome. Every test was conducted once at baseline and once at follow-up investigation.
In
this study we considered objectively recorded data on mobile phone use
collected from the Swiss mobile phone operators as well as self-reported
data on wireless communication devices usage obtained from a written
questionnaire referring to the 6 months period prior to each
examination. In terms of RF-EMF related exposure measures we inquired
about call duration with own or any other mobile phone (referred to as
duration mobile phone calls), call duration with cordless (fixed
line) phone and duration of data traffic on the mobile phone, e. g. for
surfing and streaming. The duration of gaming on computers and TV and
number of all kind of text messages (SMS, WhatsApp etc.) are not, or
only marginally relevant for RF-EMF exposure and were thus inquired to
be used as negative exposure control variables in the analyses.
Informed
consent to obtain objectively recorded mobile phone use data from the
mobile phone operators was given by 234 out of 439 study participants
and their parents. This included duration of each call and on which
network (GSM or UMTS) it started, number of SMS (text messages) sent per
day and amount of volume of data traffic (MB/day). Data were obtained
for up to 18 months, 6 months before baseline until follow-up
investigation.
A particular strength of this study is the
longitudinal design. To the best of our knowledge this is the first
longitudinal study on memory performance in adolescents using not only
mobile phone call duration as an exposure proxy, but calculating RF-EMF
dose measures derived from objectively recorded operator data and
propagation modelling. Compared to a cross-sectional design where
changes over time cannot be assessed andwhere reverse causality is of
concern, longitudinal studies allow for more robust conclusions.
..
Most relevant contributors for the brain dose are calls on the GSM
network (on average 93.3% for the whole sample based on self-reported
data and 58.7% for the sample with operator data using operator recorded
information) followed by calls with the cordless phones (4.2% and
21.0%, respectively). For the whole body dose, calls on the GSM network
(on average 66.9% for the whole sample and 19.5% for the sample with
operator data), the use of computer/laptop/tablet connected to WLAN
(12.0% and 29.1%, respectively) and data traffic on mobile phones over
WLAN (8.1% and 22.3%, respectively) counted for the most part. Less
important for the dose measures were exposure from radio and TV
broadcast transmitters (brain dose: 0.1% and 0.4%, respectively; whole
body dose: 0.3% and 0.9%, respectively) and mobile phone base
stations (brain dose: 0.6% and 3.5%, respectively; whole body dose: 2.0%
and 4.8%, respectively).
... media usage measures which are not,
or only marginally associated with RF-EMF were not associated with
figural memory performance (e.g. sending text messages, playing games,
and duration/volume of data traffic on the mobile phone). On the other
hand, mobile and cordless phone use,which involves RF-EMF exposure,
tended to be negatively correlated, although not statistically
significant, whereas the dose measures were significantly correlated in
many models. The relative high correlation between dose measures and
self-reported and objectively recorded mobile phone call duration
respectively, limits the possibility to disentangle effects due to
RF-EMF exposure or due to other factors associated with mobile phone
use.
Since we found stronger associations between RF-EMF doses
and figural memory but not verbal memory, one could speculate that this
might be due to different brain areas involved in the verbal and figural
memory tasks. The type of information being processed determines the
brain activity during encoding and retrieval and as a consequence brain
activity patterns during figural memory tasks differ fromthose observed
during verbal memory tasks. During figural memory processes, encoding
elicits bilateral prefrontal activity and retrieval increases the
activity in bilateral or right-sided temporal regions and in bilateral
prefrontal regions (Beason-Held et al., 2005; Roland and Gulyas, 1995;
Wagner et al., 1998). During verbal encoding increases in prefrontal and
temporal brain activity in the left hemisphere can be seen (Heun et
al., 2000; Iidaka et al., 2000; Reber et al., 2002; Strandberg et al
2011) and during verbal retrieval the activity in bilateral or
rightsided prefrontal regions, bilateral or left-sided temporal regions
and the anterior cingulate are increased (Beason-Held et al., 2005;
Buckner et al., 1998; Cabeza et al., 1997). Stronger overall effects
observed for figural memory processes predominantly involving the right
hemisphere compared to the verbal memory tasks mostly involving the left
hemisphere is compatible with the fact that 81.2% of the study
participants reported at follow-up to mainly use mobile phones on the
right side but only 18.8% on the left side or with no laterality
preference. Strikingly, our laterality analyses indicated indeed
stronger associations for right side users for the figural memory task
whereas the reverse pattern was seen for the verbal task. However, the
sample size of the laterality analysis was small for the subgroup with
left side or no side preference for mobile phone use (n= 80).
We
considered a number of potential confounders and adjusted model
estimates were relatively similar to the crude model estimates, which
indicates that confounding seems not to have a substantial impact on the
results. Nevertheless, we cannot exclude that we have missed a relevant
confounder ....
Conclusion
The observed striking
pattern with more consistent associations for RF-EMF dose measures
compared to usage measures and no indications of associations for
negative control exposure variables may indicate that RF-EMF exposure
affects the figural memory of adolescents. However, given the complex
correlation structure for various exposure measures and the uncertainty
in the RF-EMF dose calculation, the observed associations need to be
interpreted with caution.
Joel M. Moskowitz, PhD, Director, Center for Family and Community Health, UC
Berkeley School of Public Health. Dr. Moskowitz is an associate producer
of the movie