Handphone: No proof of cancer link, but don't talk too long

It is not scientifically proven that radiation from the use of mobile telephones or cellular handphones can lead to the growth of brain tumours.

However, there is one piece of advice is - don't talk too long on the phone, especially children, who may be sensitive.

That was the answer from Malaysian Communications and Multimedia Commission (MCMC) Sandakan Branch Office Deputy Director, Aaron Tan, during a question and answer session following his presentation on "Radiation from Mobile Telephone Base Stations" at the ICT Hi-T Public Talk at Wisma Bandaraya, Saturday.

The event was jointly organised by the Sabah Computer Society and State IT Advancement Unit in conjunction with ICT Month (November).

"So far, we don't have to worry about radiation from the mobile phone base station. Based on the survey done, the maximum radiation from the mobile phone tower (close to antenna) is only 0.01 miliWatt per centimetre square.

"Radiation from a mobile phone tower (on the ground outside buildings) is 0.004 miliWatt per centimetre square. All the base stations that have been installed on the tower or on the rooftop are very safe. There is nothing to worry about radiation from the base station," Tan said.

According to him, in most accessible places around mobile telephone systems, the radio frequency (RF) and micro-wave (MW) radiation levels are very low (<1.5>

Mobile phone radiation is defined as radio frequency (RF) and micro-wave (MW) radiation, and also as electromagnetic wave.

According to Tan, the characteristics of RF and MW fall under the Non-Ionizing Radiation (NIR) category, and relate to field strengths versus distance.

"RF and MW radiation exists everywhere but it cannot be detected by normal human senses. However, it can partially be felt when exposed to high-field strengths with the repulsion of body hairs.

"We know the public are very worried about getting cancers from radiation through the use of mobile phones.

"Based on the measurement of mobile phone radiation, its level is low if the handset is off. You get a very small signal. Its power density is only 0.0055 miliWatt per centimetre square.

"When you switch on your handphone, the radiation level is only 0.1 miliWatt per centimetre square. And when your handphone is on standby, radiation is minimum.

Tan also enlightened on the exposure limits for the public, which were set by an international body to protect the public. Asked on the penetration of RF & MW radiation into the human body, he said iit depends on the frequency.

"Lower frequency like that in TV and radio is more penetrating than the higher frequency (in handphone, radar and MW communication). Which means the handphone radiation is not really that penetrating compared with TV or Radio radiation."

Mobile telephone users were also told to try to avoid going near mobile telephone base stations, which are all over the place. Such base station may be on a tower on the ground (outside buildings), on the rooftop of a building or indoors.

Indoor base stations are mostly installed in shopping complexes to cover indoor areas. "Talking of exposure from a mobile phone tower, if the measurement is 100 miliwatt per centimetre square, this is a very clear hazard. We don't allow this to happen."

He said the field strength or radiation will decrease exponentially (or 1/Distance2). "That is, if you are nearer or one metre from the antennas in the base station, you will get around 900 microWatt per centimetre square.

This means the radiation level is approaching the Exposure Limit (EL) for the public. But as you go farther (a 3-metre distance), you will only get around 100 microWatt per centimetre square.

"To be safe, it would be a good idea to stay in a building because it is 10 to 100 times lower compared with outside the building. This is what we mean by building attenuation."

Based on a radio frequency (RF) survey done on radiation from a directional antenna (base station), he said if you are 50 to 200 metres from the station, you will be getting around 1/1000 from the exposure limit (EL).

"It means the signal or exposure you are getting is very low compared with the EL. Furthermore, you will get it from certain directions only, so it is safe to be on the left and right-hand sides of the antenna."

On radiation from a rod antenna (handphone), he said the handphone transmits in all directions but its signal is very low.

Responding to the Sabah Computer Society President Taitim Tulas who wanted to know the potential danger of a mobile telephone's proximity to the body (when placed in a pocket or around the waist) for a long period, Tan said no survey has been done on this and neither was there any complaint of negative effects on health as a result of doing so.

To another question, he said any telecommunication equipment brought into the country will be checked by the Malaysian authorities to ensure it is safe for use, unless it is brought in illegally.

"It has to be tested accordingly before the public are allowed to use it."

Furthermore, he said there are several guidelines for compliance if the service provider wants to put up a mobile telephone base station.

"The consideration is where and how far the base station would be from the public."

Also present were the Director of State IT Advancement Unit, Bruno Vun, Organising Chairperson Karen Wong, avid blogger Mark Mojitoh from the Sabah Credit Corporation who gave a talk on Blogging and Alex Ku from the Malaysian Open Source Training Centre who spoke on Wireless Networking & Ethical Hacking.

TAN said measurement of mobile phone radiation is important for two reasons. Firstly, RF radiation is not detectable by human senses.

Secondly, RF radiation at close distance is suspected to be hazardous to human health.

He said RF radiation is measured by using a special survey instrument that can measure the field strengths.

According to Tan, the Malaysian Institute of Nuclear Technology (MINT) has carried out radiation safety assessment at more than 16 mobile telephone base stations and more than 15 TV and Radio Broadcast Stations throughout the country.

"This is how they assess the radiation hazard. A complete radiation survey during commissioning (onsite and offsite); regular and special workplace radiation surveys during operation and maintenance (onsite); and personnel exposure measurements (onsite)."

With the aid of graphs showing radiation from mobile telephone base stations (rooftop), Tan noted that the measurement is slightly higher (around 0.025 miliwatt per centimetre square).

MINT had also come to Sabah to measure mobile phone radiation at the site of several base stations (on the ground, inside building and rooftop).

"Results show that you will be getting higher radiation from a base station on the ground (that is the tower). There is more signal or radiation from the ground (outside buildings) compared with a base station that is inside buildings and also on the rooftop. Radiation from a base station on the rooftop is low, only a small signal."

On the results of a RF survey around TV and Radio Stations, Tan said the radiation level is 0.9-8 microwatt per centimetre square for a 300-foot tower.

"But if the tower is lower, you will get more radiation actually because it is nearer to you."


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