No effect of EMFs on cardiovascular system
In 1998 Braune and colleagues created a stir by reporting that exposure to an electromagnetic field (EMF) generated by a mobile phone was associated with an increase in blood pressure. This group has now repeated the experiment but with one crucial difference - the subjects were exposed to the EMF or sham-exposed in a random manner, whereas in the first study the subjects were all sham-exposed first. In the new study the blood pressure again increased by about 5 mm Hg in the course of an experiment but this was independent of the EMF exposure. In other words, the EMF was not associated with any change in the cardiovascular measures that were assessed during the experiment.
This study illustrates the importance of randomization of exposure. It also demonstrates the necessity for studies to be replicated. A key factor in assessing whether a causal relationship exists between an exposure and an outcome is the consistency of the finding of an association in different studies.
For more on this, see "Research - Clinical Experiments - cardiovascular effects".
Braune S, Riedel A, Schulte-Monting J, Raczek J (2002). Influence of
a radiofrequency electromagnetic field on cardiovascular and hormonal
parameters of the autonomic nervous system in healthy individuals. Radiation
The Swedish Radiation Protection Authority, SSI, has published a review of epidemiological studies of cellular telephones and cancer risk. SSI commissioned Drs. Boice and McLaughlin from the International Epidemiology Institute in Maryland, USA, to carry out the review. The authors state: "A few studies in the United States and Sweden are non-informative, either because the follow-up was too short and numbers of cancer too small (USA) or because of serious methodological limitations (Sweden). In contrast, five well-designed epidemiologic studies have been conducted in three countries by investigators using different designs In our view, a consistent picture has emerged from these studies that appears to rule out, with a reasonable degree of certainty, a causal association between cellular telephones and cancer to date".
The review can be read at www.ssi.se/ssi_rapporter/pdf/ssi_rapp_2002_16.pdf
Boice JD, McLaughlin JK. Epidemiologic studies of cellular telephones
and cancer risk - a review. Swedish Radiation Protection Authority,
A new US $1.3 million research centre is to be established in Australia to study the possible health effects of electromagnetic energy emissions from mobile phones and mobile phone towers. The National Health and Medical research Council will support an actual or "virtual" Centre of Research Excellence in Radiofrequency Electromagnetic Energy over the next five years.