Effects of EMF - Do EMFs Cause Adverse Health Effects?

More than twenty-five years of research has produced a lot of data, a lot of answers, but not the answer. Research has been performed on both the electric and magnetic field components of EMF. However, it has generally focused on the magnetic field component as this has raised more issues than electric fields. There have been two main areas of research.

in real life – epidemiology

Epidemiology is about people. This research looks at statistics to see if there are patterns of disease in large groups of people. The difficulty with large statistical studies is that they take several years to produce meaningful results, and even then, there are different opinions about how the results should be interpreted. There may be other factors in the study (such as how EMF is measured or patient histories) which could complicate the interpretation of the results. Some studies have reported statistical links between EMFs and cancer while others have not. Scientists generally agree that the epidemiological studies aren’t strong enough by themselves to establish that adverse health effects exist.

in the laboratory

Researchers have also studied living cells in laboratory experiments as well as animals and human volunteers to see if EMFs have any effects. Some experiments have shown small changes to cells, but no one knows why these changes occur, or whether they represent a health risk. Lack of consistency in the results of the laboratory studies is one reason why scientists treat the weak positive results from some epidemiological studies with scepticism.

recent scientific review findings

Because of the large number of scientific studies, it can be misleading to draw conclusions from any single study. For this reason, bodies which set health standards rely on detailed reviews of the total body of the science. Bodies such as the World Health Organisation (WHO) and national health authorities continually review the results of experiments from all over the world. Two major reviews of the science have been carried out recently: in 1999 by the US National Institute of Environmental and Health Sciences (NIEHS), and in 2001 by the UK National Radiological Protection Board (NRPB), now part of the UK Health Protection Agency.

The NIEHS review found: “The scientific evidence suggesting that ELF-EMF exposures pose any health risk is weak. The strongest evidence for health effects comes from associations observed in human populations with two forms of cancer, childhood leukemia and chronic lymphocytic leukemia in occupationally exposed adults. While the support from individual studies is weak, the epidemiological studies demonstrate for some methods of measuring exposure, a fairly consistent pattern of small increased risk with increasing exposure that is somewhat weaker for chronic lymphocytic leukemia than for childhood leukemia. In contrast, the mechanistic studies and the animal toxicology literature fail to demonstrate any consistent pattern across studies although sporadic findings of biological effects have been reported. The lack of connection between the human data (epidemiological) and the experimental data (animal and mechanistic) severely complicates the interpretation of the results.”

“The NIEHS concludes that ELF-EMF exposure cannot be recognised as entirely safe because of weak scientific evidence that exposure may pose a leukemia hazard.”

“Passive regulatory action is warranted such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures.”

The NRPB report concludes: “Laboratory experiments have provided no good evidence that extremely low frequency (ELF) EMFs are capable of producing cancer, nor do human epidemiological studies suggest they cause cancer in general. There is, however, some epidemiological evidence that prolonged exposure to higher levels of power frequency magnetic fields is associated with a small risk of leukaemia in children”, but goes on to say that “...the epidemiological evidence is not strong enough to justify a firm conclusion that such fields cause leukaemia in children.”

In 2001, the International Agency for Research on Cancer (IARC), a part of the World Health Organisation, classified power frequency magnetic fields as a “possible carcinogen”, based on recent epidemiological study findings which associate childhood leukemia with higher levels of exposure to residential magnetic fields. They comment that no scientific explanation has been established for the observed association.

In Australia, the relevant health authority is the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), an arm of the Commonwealth Department of Health. ARPANSA has some relevant information brochures available on its web site including: “Does Electricity Cause Cancer?”, “Electricity and Health” and “The Controversy over Electromagnetic Fields and Possible Adverse Health Effects”. The first is a direct response to the NRPB report from the CEO of ARPANSA. One quote is of particular interest:

“It is also important not to fixate on the location of external power lines, including high voltage transmission lines, as the prime cause of exposure. Exposure to ELF magnetic fields can arise from ground currents, internal household wiring and the use of electrical appliances as much as from exposure to external powerlines.”

The other two brochures contain more general information on the relationship between electricity, mainly EMF, and health. They broadly conclude: “On balance, the scientific evidence does not indicate that exposure to 50 Hz EMFs found around the home, the office or near power lines is a hazard to human health.”