SEOUL - Mobile phones, which more than 28 million Koreans use daily, may cause possible health risks.

According to the Seoul National University’s protective medical team, led by Professors Ahn Yoon-ok and Kang Dae-hee, long-term exposure to the radio wave emitted by mobile phones could affect a human body, causing several health disorders such as eye fatigue, earache, nausea and dizziness.

Based on an interview with 472 mobile phone users, the report also found that long-term cellular phone users are exposed to more health risks than short-term users.

The study is expected to ignite fresh debate over the safety of mobile phones. It was the first evidence to be publicly available in the country.

The research team said people who use their phone over 71 minutes per day have experienced 2.7 times more earaches than those who use their phone less than 14 minutes per day.

It also showed that long-term users should pay more attention to mobile phone safety. In terms of accumulated usage times, once a user has spoken on the phone for more than 1,350 hours, about 56 days, they are prone to a higher risk of nausea (4.9 times) and dizziness (3.4 times) compared with people who have only ever used a mobile for less than 150 hours, about 6 days.

However, the team said there is not yet enough information to conclude that they pose a risk, saying that research is still underway.

"It may take many more years before a definitive conclusion can be reached on whether mobile phone emissions pose any risk to human health," they said.

Although there have been pros and cons about the possibility of a health risk triggered by mobile phones, no obvious theory has been disclosed.

Scientists said mobile phones are low power radio devices that transmit and receive microwave radiation at frequencies of about 900 Megahertz (MHz) and 1800 MHz.

Cellular radio systems involve communication between mobile telephones and fixed base stations. Each base station provides coverage of a given area, termed a cell. While cells are generally thought of as regular hexagons, making up a honeycomb structure, in practice they are irregular due to site availability and topography.

Still, there is consensus among international bodies that exposure guidelines for radio waves should be set to prevent adverse health effects caused by either whole or partial body heating. Some of the energy in the radio waves emitted by mobile phones is absorbed in the head of the user, mostly in superficial tissue, said the report.

According to the National Radiological Protection Board based in the United Kingdom, exposure guidelines relevant to mobile phones are therefore expressed in terms of absorbed energy in a small mass of tissue in the head.


In practice, the output from mobile phones used in the UK results in only a fraction of this amount of energy being deposited in the tissues of the head, and therefore the rise in temperature would only be a fraction of a degree. This is similar to the normal daily fluctuations in body temperature and such small changes in heat load are considered to be too low to cause adverse effects.

Concerns about other possible effects arising from exposure to mobile phone frequencies have also been raised. These include suggestions of subtle effects on cells that could have an effect on cancer development or influences on electrically excitable tissue that could influence the function of the brain and nerve tissue.

However, radio waves do not have sufficient energy to damage genetic material (DNA) in cells directly and cannot therefore cause cancer, it said.

There have been suggestions that they may be able to increase the rate of cancer development, for instance, by influencing cancer promotion or progression, and about whether there could be effects on brain function, with particular emphasis on headaches and memory loss.