Mobile base stations OK

The Phnom Penh Post
http://www.phnompenhpost.com

Written by Kong Marry
Monday, 11 May 2009

Dear Editor,

Economic growth in Cambodia has attracted many investments in telecommunications, especially cellular networks. There are now nine mobile operators. This will substantially increase the number of mobile phone base stations across the country.

Recently, there have been growing concerns among Cambodian people who are living near mobile phone base station antennas about the adverse effects of the antennas on their health.

Research about the radio radiation effects on the human body has been conducted over 50 years on a global scale. Researchers have come to the conclusion that radio waves for wireless communication do not cause any harmful effects on the body although ongoing research is still being carried out worldwide.

To understand the effect of base station antennas on the body, it is first important to note that mobile operators in Cambodia are deploying mobile communication systems such as GSM/GPRS and 3G networks. These cellular systems operate at the frequency range of 800MHz from a CDMA network, 900MHz and 1800 MHz for GSM networks, and 2100MHz for 3G networks.

My points are, firstly, radio frequency (RF) radiation. There are two categories of RF: ionising and non-ionising. Technically speaking, ionising radio frequencies such as X-ray and Gamma-ray can, when it collides with biological materials, create negative and positive particles, which may cause problems for human health. Non-ionising radio frequencies do not have enough energy to ionise atoms from the materials, which means they cannot cause any health hazards to human beings. Radio frequencies of cellular networks (800MHz - 2100MHz) fall within the non-ionising category. Therefore, it indicates that the radio radiation from mobile base station antenna doesn't pose any threats to human health.

The other important factor is called the exposure level or, in technical terms, power density measured in microwatts per square centimetre and abbreviated as µW/cm². There is a limit to how much the human body can be exposed to the power density from the base station antennas.

In the US, the Federal Communications Commission (FCC) limits the exposure level to no greater than 580 µW/cm² . It has been found that the exposure level or power density very near the typical cellular base station antennas is on the order of 1 µW/cm² or less. Although there is no published report on the exposure level of mobile base station antennas in Cambodia, it is very unlikely that it would exceed the allowed level specified by various countries when all operators are deploying standardised cellular systems developed by recognised industries.

In conclusion, people living near base station antennas should not be concerned about the adverse effects of mobile base station antennas on their health. However, the government of Cambodia should continue to work with mobile operators to ensure that they conform to safety requirements. More effort should also be made to raise people's awareness on this issue by publishing the reports on mobile base station data and any other useful information so they understand that their community is not being harmed by the development of telecommunications in Cambodia.

Kong Marry
Waseda University, Japan

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