General considerations

Scientific research into the potential health effects following radiofrequency (RF) exposure attempts to answer the following questions:

It is not possible for science to prove there is no risk. It is only possible for science to prove, under certain exposure conditions, that an effect does exist. Further, assessing a potential health hazard requires a comprehensive body of scientific evidence that is not likely to occur, in the case of RF, in the short term. A critical review of the science requires the consideration of relevant published studies where the evidence is evaluated on the merits of the research design and conduct of the study. Replication studies, which attempt to provide evidence for the same effect under the same conditions, are very important. Ultimately, an accumulation of well-designed and well-executed studies producing results of similar magnitude and strength provides increasing confidence of the absence or presence of a significant health effect. There are different types of research studies. The two main groups are experimental and epidemiological.

Epidemiological studies investigate associations between health effects, characteristics of people, and exposure to different factors. The advantages and disadvantages of these studies are discussed further in "Human Epidemiology". In experimental studies, sometimes called laboratory studies, the conditions of the study are under the control of the investigator.

More weight is placed on research involving human subjects. Some short-term human experimental studies have been done using RF radiation, but longer-term research, such as that needed to investigate a possible association with cancer, relies on epidemiological studies. Most laboratory studies are done on individual human or animal cells (in vitro) or on animals (in vivo). These are discussed at greater length in the introduction to "Clinical Experiments".

In general, there is an accepted hierarchy of research studies: Human research is considered more relevant than animal studies, which in turn are given greater credence than cellular studies. Even within animal research, some studies might contribute more than others to our understanding of association between human disease and, say use of cellular phones. Lifetime studies involving chronic exposure to RF radiation at cell phone frequencies and power might tell us more than short-term exposure to higher power radiation.

A number of scientific groups and panels have issued detailed reports and these can be seen in "Review Panel Reports". These provide an overview of the health effects of exposure to radiofrequencies.

Useful sources of information about current research are the WHO and IEEE databases, which can be found at http://www.who.int/docstore/peh-emf/EMFStandards/who-0102/Worldmap5.htm


Summary of human research

In the sections to follow, the research studies examine the effects of exposure to either radiofrequency radiation (RFR) in general, or specifically to the radiation from cell phones.

Epidemiology:

The epidemiological studies mainly examine cancer, but a few concentrate on general health symptoms. The cancer studies are covered in detail in the "Epidemiology" section.

There are some studies relating to general health symptoms, covering a variety of health issues.

Clinical:

In this section there are a variety of studies that examined other biological health effects. They are summarized in detail in each sub-section.

Electrencephalography (EEG) experiments have been done in a variety of situations with volunteers exposed to RFR of the type associated with cell phones. Some have been done while the subjects were awake and resting, others while they were asleep, and others while they performed different tasks. The striking finding was a lack of consistency in the results.

This was true also of cognitive function studies. Some found an accelerated response in exposed subjects in a few tasks, but in one of these studies, a replication attempt by the same authors (Haarala, 2004) failed to show the same effect. The overwhelming majority of the tasks showed no effect in the RFR-exposed group, and there was marked inconsistency in the results that appeared to show an effect.

Hormone studies have been almost entirely negative.

Experiments on cardiovascular effects, such as pulse rate and blood pressure, have been negative, although one group (Braune, 2002) initially reported a slight increase in blood pressure, only to retract their findings when further study showed their study design to have been flawed.

"Other" studies starts with a discussion of general health effects, including hypersensitivity. This is followed by sub-sections in the areas of hearing, the immune system, and temperature control.

Please note: A large number of scientific articles are discussed in this "Research" section of the website. At the end of each subsection, a list of references is given, and each reference is linked directly to a summary of the scientific article.