Onli in da Pilipins.
A Makati regional court ordered the National Transmission Corp. to effectively dismantle the 230-kilovolt Sucat-Araneta-Balintawak line, on the strength of a Supreme Court ruling favoring Dasmarinas Village in Makati in its petition against the power transmission lines passing near the village.
The well-heeled residents of the Village probably saw an eyesore on the overhead lines, but they could not just petition for their removal without an emotional and hopefully convincing reason. They have found it in anecdotal stories of the supposedly harmful effects of electromagnetic fields (others use the dreaded word radiation which is not applicable here) on health which our esteemed judges apparently agree.
The Trade department warned on hurting the country’s attractiveness as a result of the dismantling of the lines which supply power to large portion of the Makati Business District itself, most of Manila and Quezon City, Bulacan, parts of Caloocan City, and the whole of Novaliches, Malabon and Valenzuela. The Energy department meanwhile worries about the effect on the industry and businesses.
But nobody shows concern regarding a very fundamental worrying trend in local jurisprudence: disregard of science over technicalities, legalities or influence of powerful groups?
Electromagnetic fields comprise of electric (E) and magnetic (H) waves, traveling together at the speed of light and are characterized by a frequency and a wavelength. The frequency, which is the number of oscillations per second is measured in hertz (1 hertz = I cycle per second) while the wavelength is the distance traveled by the wave in one cycle. What is dealt here is extremely low frequency (ELF) fields which are defined as those having frequencies up to 300 Hz. The electrical cycle we use is 50/60 Hz.
At these low frequencies, the wavelengths are very long; 6000 km at 50 Hz and 5000 km at 60 Hz. For all intents and purposes, the electric and magnetic fields are independent from each other and can be discussed separately in the present context.
The electric and field strength is measured in volts per meter (V/m) or kV/m. Magnetic field strength on the other hand is measured in millitesla (mT) or microtesla (uT). The magnetic field itself is created by current flow.
Naturally occurring 50/60 Hz electromagnetic fields have extremely low values of the order of 0.0001 V/m and 0.00001 uT. Underneath transmission lines, the field can be as high as 12 kV/m and 30 uT and around a generating station the values could reach 16 kV/m and 270 uT.
After reviewing all available studies, the World Health Organization found no conclusive evidence linking extremely low frequency (ELF) electromagnetic fields which are found in transmission lines, to any of the purported health effects. The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is blunter,saying 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.
Available evidence suggests that the effects electric field strength of up to 20 kV/m are innocuous, while in animals exposed to 100 kV/m over a prolonged time have no deleterious effects on their reproductive cycles. A health effects study on a community which has been in place for at least 10 years under a 400 kV DC Pacific Intertie power line in California shows no significant or consistent relationships between exposure to the high voltage line and the perceived ill health effects (Haupt and Nolte, 1984).
The line is almost double in voltage than in Dasma, and in addition, the DC line is in corona; which means it is generating ions in the vicinity of the conductors that affect the magnitude of surrounding electric fields and ion concentrations.
On magnetic effects, a WHO study which exposed volunteers for several hours to ELF strength of up to 5000 uT (more than 20 times the value in generating stations) show negligible effect on blood changes, ECG, heart rate, blood pressure and body temperature.
For a more detailed discussion on health effects of EMFs, see the ARPANSA website.
The bottom line is the magnitude of the ELF fields in the environment produce current that is less than the currents naturally produced by the body.
So, our judges and lawyers should at least learn enough science or at least consult those with appropriate knowledge before promulgating far-reaching judicial pronouncements.
Since they are terrified of modern conveniences, the Dasma residents should have their electrical supply disconnected for their peace of mind. Then they could celebrate their court victory around a bonfire, much like the victory celebration of Sitting Bull over General Custer at Little Big Horn. They could also have their dinner under candle lights, which is far more romantic than under fluorescent lamps.
They should also refrain from using their high-end 3G phones which are supposed to emit emf waves at much higher frequencies.
The real loser here is science.
Reference:
R. C. Haupt & J. R. Nolte. (1984) The effects of high voltage transmission lines on the health of adjacent resident populations. Am. J. Public Health, 74, 76-78.
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