of methods used to assess cell phone exposure
of the major challenges that researchers face when conducting
epidemiological studies of cell phones is the difficulty in accurately
assessing the exposure of an individual to the radiofrequency
radiation from the phone. The two methods most commonly employed
are self-reported use and using data on subscriptions that are
supplied by a network provider. Schüz and Johansen compared
these two methods, using data from two studies that they were
able to cross-link. They found "fair"
agreement between the two methods. However, they point out the
limitations of both methods, and argue that these limitations can
be minimized in prospective studies, with exposure estimation based
on traffic records on current use of a cellular telephone.
For more on this subject, see "Research
- Exposure assessment".
Schüz J, Johansen C. A comparison of self-reported cellular
telephone use with subscriber data: Agreement between the two
methods and implications for risk estimation. Bioelectromagnetics
International Commission for Electromagnetic Safety (ICEMS) held
a conference entitled The Precautionary Approach: Rationale,
Legislation, and Implementation.The City of Benevento, Italy,
hosted the conference on February 22-24, 2006. The meeting was
dedicated to W. Ross Adey. The scientists at the meeting drew
attention to their concern that electromagnetic fields (EMFs)
can have adverse effects, and made a number of recommendations
to minimize exposure to EMFs.
Resolution can be found at:
Electromagnetic Biology and Medicine 2006;25:197-200.
RFR exposure and heart rate variability
and colleagues tested the effect of radiofrequency radiation
(RFR) exposure at 900 MHz on the heart rate variability (HRV)
on young adults. The found no effect on the main outcome of R-R
interval on the electrocardiogram, and on most of the other parameters,
but a weak effect on some. This latter effect was suggestive
of an effect on the sympathetic component of the autonomic
For more, see "Research - Clinical
Parazzini M, Parazzini P, Tognola G, Thuroczy G, et al. Electromagnetic
fields produced by GSM cellular phones and heart rate variability.
Go to summary>
Interphone study of intracranial tumours
Interphone study - this one from Norway - has been published.
There was no evidence from the study that cell phone use is associated
with an increased risk of gliomas, meningiomas,
or acoustic neuromas.
The authors discuss the common limitations of epidemiological studies,
studies. These include selection and recall bias, and misclassification.
They also caution that the time interval since the introduction
of cell phone use may be too short to detect possible effects
of cell phone use.
For more, see "Research - Epidemiology",
and "Research Programs
- Interphone study".
Klaeboe L, Blaasaas KG, Tynes T. Use of mobile phones in Norway
and risk of intracranial tumours. Eur J Cancer Prev 2007;16:158-164
Go to summary>
Correlation of health indicators
with population density and power output from cell phones
Hallberg reports that a variety of health indicators have shown
a decline since 1997 in Sweden. In an ecological analysis he reports
that people in sparsely populated counties had more illness, and
that the indicators correlated strongly with estimated cell phone
area coverage and power output.
ecological analysis is the weakest type of epidemiological study.
It is subject to a bias known as the ecological fallacy (Last
JM, A Dictionary of Epidemiology, 1988), which may occur because
an association observed between variables on an aggregate level
does not necessarily represent the association that exists at
an individual level. There may be a number of factors that can
explain an observed correlation. For more, see "Research
- Exposure Assessment".
Hallberg O. Adverse health indicators correlating with sparsely
populated areas in Sweden. Eur J Cancer Prev 2007;16:71-76.
Go to summary>
of an EMF hypersensitivity questionnaire
and colleagues from the UK have developed an electromagnetic
hypersensitivity questionnaire. The authors consider that the
scale provides an index of the type and severity of symptoms
commonly experienced by people believing themselves to be EHS
and a screening tool that researchers can use to pre-select the
most sensitive individuals to take part in their research.
For more, see "Clinical -
Others- General health symptoms".
Eltiti S, Wallace D, Zougkou K, Russo R, et al. Development and
evaluation of the electromagnetic hypersensitivity questionnaire.
Go to summary>
and colleagues have published a report on a "Workshop on
Base Stations and Wireless Networks" that was convened by
the World Health Organization. The report details sources of
radiofrequency radiation (RFR) and their exposure levels. It
discusses mechanisms that would be required of RF energy to change
physiological function, initiate dysfunction, or cause the onset
of disease in humans or animals. It briefly summarizes research
that that has been done on the health effects of RFR exposure.
The report also assesses the problems in risk communication in
Valberg PA, van Deventer TE, Repacholi MH. Workshop report: Base
stations and wireless networks - radiofrequency (RF) exposures
and health consequences. Environ Health Perspect 2007;115:416-424.