Radio signals for the next generation of mobile phone services can cause headaches and nausea, according to a study conducted by three Dutch ministries.

The study, the first of its kind, compared the impact of radiation from base stations used for the current mobile telephone network with that of base stations for new third generation (3G) networks for fast data transfer, which will enable services such as video conferencing on a mobile device.

A base station, which usually covers a "cell" area of several square kilometres, transmits signals to mobile phones with an electromagnetic field.

"If the test group was exposed to third generation base station signals there was a significant impact ... They felt tingling sensations, got headaches and felt nauseous," a spokeswoman for the Dutch Economics Ministry said.

There was no negative impact from signals for current mobile networks.

However, cognitive functions such as memory and response times were boosted by both 3G signals and the current signals, the study found. It said people became more alert when they were exposed to both.

Dutch government ministers responsible for Economic Affairs, Health and Telecommunications said follow-up research was needed to confirm the findings as well as to look at any longer-term health effects and biological causes.

They will also discuss the study with the European Commission, the spokeswoman said.

The double-blind laboratory tests - meaning no one in the survey knew if a 3G-like base station was actually transmitting signals - exposed test subjects to expected levels of average radiation for 3G networks when they become commercial.

The GSM Association, a global organization of mobile telecommunications operators, said it was studying the report and could not comment.

The study, conducted by the Dutch technological research institute TNO, was the first to look for an impact of mobile telephones on well-being. It was also the first study to find a statistically significant negative impact from 3G base stations.

Previous research on a negative health impact of mobile phones, mostly second-generation, has been inconclusive. Existing research gives no scientific evidence that second-generation phones cause brain tumours, while a long-term study by the International Agency on Research on Cancer is not expected to yield results before 2004.

Previous research did find an impact on cognitive functions, which was also found in the Dutch survey. But TNO noted that earlier studies always measured the impact of cellphones held close to the head, causing high fields of radiation close to the ear and warming of the brain.

TNO's study used lower a dose of radiation to mimic base station signals rather than handsets.

Handsets emit stronger radiation when they are used, while base stations transmit more constant levels of radio signals, exposing everyone within range.

(People's Daily   October 10, 2003)