Here on earth, we are constantly bathed in electric fields. There are extensive fields from the charge in the ionosphere and thunder cells provide periodic but potentially (no pun intended) lethal electric fields. There are also a myriad of various micro-electric fields within nearly every living organism associated with the nervous system and cell transport processes. And there are changing electric fields created by man's electrical devices and power transport systems. We will focus on the last item.
The ELF Health Issue
The danger of intense microwaves is no suprise to anyone. Everyone knows what happens to things subjected to microwaves in the microwave oven. The microwave broadcasting industry is closely regulated by the government to assure that no one is subject to damaging intensities. But microwaves have frequencies in the Giga Hertz range and their effects in biological specimens is well understood. This is not the case for extremely low frequency (ELF) radiation.
| A few decades ago, there was a short-lived "scare" when several preliminary epidemiological studies indicated that people living near high tension (i.e. high voltage) lines had a higher rate of cancer than the national average. The suggested culprit was extremely low frequency (ELF) electromagnetic fields (EMF's) coming from the 60 Hz current flowing in the lines. (As we will discover later in the course, electromagnetic fields are composed of changing electric and magnetic fields. It is not known which, if either, could cause biological effects. However, the magnetic field is the most likely candidate.) |
The power industries quickly dismissed the findings and their view was generally supported by the science community. Why? Although the people in the study did suffer from higher than average cancer rates, a high percentage also lived in areas that were generally unhealthy...i.e. heavy industrial areas. From the biologist's point of view, the strength of the electric and magnetic fields generated by the high tension lines was many orders of magnitude below the values associated with known biological processes.
However, there has been a great deal of research and additional studies since then. The conclusions are mixed. Some epidemiological studies support the contention while others do not. Many biological research institutions are presently investigating the possibility that very weak fields can have measureable biological effects. A good starting point to establish some background for the debate is a 1990 OSHA memorandum that is based upon a literature review of the ELF issue.
The BENER Digest (Biological Effects of Nonionizing Electromagnetic Radiation) predominantly holds the view that ELF's are truly a problem. Whereas, ARPANSA (Austrailian Radiation Protectiona and Nuclear Safety Agency) in assessing the Doll Report takes a very different view. And the National Institute of Environmental Health Sciences (NIEHS) has an extensive site that outlines the methods of research of many of the ELF studies. Compared to the the two previous sites, the NIEHS deals more even-handedly with the interpretations of these studies.
A simple net search for low frequency radiation will provide many thousands of hits offering a full range of opinions. If you are interested in pursuing this subject, do not limit yourself to just these few links. For those interested about this issue on the political front, check out the site maintained by the Environmental Law Institute and search the database for ELF.
Be sure to enter your full name. Enter your email address ONLY if you want the number of points awarded e-mailed to you. Responses should be brief but complete. You must click the SUBMIT button to submit your entry. Entries are due by noon on Monday of next week.
Questions: