History of Electromagnetic Field Issues
- What is the electromagnetic field (EMF) issue?
- We would like to answer the question by explaining the history of 50 and 60 Hz EMF generating from power utilities.
Researchers in the United States surveyed the health of people living near transmission lines in the 1970s. They survey resulted in a report for early childhood leukaemia indicating that the power line EMF could be related to childhood leukaemia. This report opened public and news media discussions on to which extent the EMF generated from electricity used in our daily lives may adversely affect our health.
◆Lawsuit against the 765 kV very-high voltage transmission line construction project (USA)
Residents opposing the construction of 765 kV ultra-high voltage transmission lines in New York State filed a lawsuit in 1973. The New York Public Service Commission mediated the case, compromising as follows:
1) The electric field shall be limited to 1.6 kV/m, which is the level beneath existing transmission lines
2) The construction of new 765 kV transmission lines shall not be approved unless they are confirmed safe
3) The project owner shall research EMF effects to confirm safety
After the commission’s decision, the New York State transmission line project was resumed and surveys and research on EMF effects were planned. Under the project, proactive research was implemented from the middle of the 1970s and into the 1980s, culminating in the announcement of the final report in 1987. The report concluded that no scientific evidence was identified that power-frequency EMF in living and working environments adversely affect the human body and health.
◆Epidemiological survey by Wertheimer & Leeper in 1979 in the USA
US epidemiologists Wertheimer & Leeper disclosed the results of an epidemiological study in 1979 on the relation between power-frequency EMF and human health.
The case-control study analysed data related to the death of 344 children of childhood leukaemia from 1950 to 1973 in Denver, Colorado. The results suggested the higher cancer mortality rate for children living near distribution lines.
◆Epidemiological survey of Savits in 1987 in the USA
Savits, et al. at the School of Hygiene and Public Health, University of North Carolina, released a survey in 1987 which indicated that children younger than 14 years who were living near distribution lines had a 1.5 to 2 times higher incidence rate of childhood cancer (especially childhood leukaemia) than those living away from distribution lines.
The epidemiological study report, indicating a higher incidence rate, attracted public attention mainly because Savits was a well-known epidemiologist.
◆Epidemiological survey at the Karolinska Institute in Sweden in 1992
Dr. Feychting and Dr. Ahlbom at the Karolinska Institute in Sweden in 1992 released an analysis of data collected in Sweden for the period from 1960 to 1985 which suggested that children living within 300 m of transmission lines had a relative risk ratio of childhood leukaemia 2.7 times higher than that of other children if the EMF exposure level (calculated value) is 0.2μT or higher.
After such reports of epidemiologists from USA and Sweden were released, mass media began aggressively to cover EMF health issues, and the general public became more and more aware of EMF issues.
Governments and international organizations concerned have been urged to address the EMF issue.
◆Major EMF research from international organizations
☆ The World Health Organization (WHO) announced in its Environmental Criteria No. 69 (magnetic field) in 1987 that an inductive current density of 1 mA/m2 (equivalent to a 500 μT magnetic field level) or under has no established health effects.
☆ In 1991 the US government announced a six-year research and public relations project on EMF (EMF-RAPID Program) beginning from 1993 at a cost of approximately 41 million US dollars in accordance with the Energy Policy Act (the bill passed in October 1992).
☆ The WHO launched the International EMF Project in 1996.
☆ The EMF-RAPID Program published the final report in 1998.
☆ The International Agency for Research on Cancer (IARC) announced the results of assessing carcinogenicity of electrostatic fields, static magnetic fields, and ELF (extremely low frequency) EMF in 2001.
☆ WHO Environmental Health Criteria Monograph No. 238 (Extremely Low Frequency Fields) published in 2007 states: "The evidence (for linkage between ELF magnetic fields and childhood leukaemia, which epidemiological study suggests,) is not strong enough to be considered causal, but strong enough to cause concern.”
A number of other diseases have been investigated for possible association with ELF magnetic field exposure. These include cancers in both children and adults, depression, suicide, reproductive dysfunction, developmental disorders, immunological modifications and neurological disease. The scientific evidence supporting a linkage between ELF magnetic fields and any of these diseases is much weaker than for childhood leukaemia and in some cases (for example, for cardiovascular disease or breast cancer) the evidence is sufficient to give confidence that magnetic fields do not cause the disease." In addition, Fact Sheet No. 322 states: "Thus, on balance, the evidence related to childhood leukaemia is not strong enough to considered causal."