This is the latest news I've come across in answering the "are cell phones bad for you?" question ("Lab Tests Show Mobile-Phone Risk"). In short, the four-year German research study says, "yes". Meanwhile, the World Health Organization is working on The Internationl EMF Project, which will assess health and environmental effects of exposure to static and time varying electric and magnetic fields in the frequency range 0-300 GHz (this covers cell phones).

From "Lab Tests Show Mobile-Phone Risk":

The research project, which took four years and which was coordinated by the German research group Verum, studied the effect of radiation on human and animal cells in a laboratory.

After being exposed to electromagnetic fields that are typical for mobile phones, the cells showed a significant increase in single- and double-strand DNA breaks. The damage could not always be repaired by the cell. DNA carries the genetic material of an organism and its different cells.

"There was remaining damage for future generation of cells," said project leader Franz Adlkofer. This means the change had procreated. Mutated cells are seen as a possible cause of cancer.

The radiation used in the study was at levels between a specific absorption rate of between 0.3 and 2 watts per kilogram. Most phones emit radio signals at SAR levels of between 0.5 and 1 w/kg.

Adlkofer advised against the use of a mobile phone when an alternative fixed-line phone was available, and recommended the use of a headset connected to a cell phone whenever possible.

"We don't want to create a panic, but it is good to take precautions," he said, adding that additional research could take another four or five years.

None of the world's top six mobile-phone vendors could immediately respond to the results of the study.