French health watchdogs, in a precautionary move, recommended on Thursday reducing exposure to mobile phones and other portable wireless devices that emit radio-frequency electromagnetic waves.

The guidelines are an interim step pending the outcome of wider research into any impacts from health from radio frequency fields.

"The time for inaction has passed," Martin Guespereau, director of the French Health and Security Agency (Afsset), said at a press conference.

"Let's not wait until the indications become pathologies before moving forward with limiting exposure," he said.

More than 1,000 studies were examined and most of them did not show any negative impacts from mobile phones, Wifi emitters, microwave ovens, cordless home phones and other gadgets emitting electromagnetic radiation, Guespereau said.

Some research, however, did point to possible health problems, including cell damage, reduced male fertility and a lower blood flow to the brain.

Emphasising caution, Guespereau also pointed out that cell phones have been widely used for barely a decade, not long enough to study long-term impacts from constant exposure.

Given this level of uncertainty, the French health authority said further research was needed to determine potential health consequences.

In the meantime, the general public is advised to exercise caution in the use of wireless mobile devices, it said.

"If an environmental exposure can be reduced, it should be," the agency said in a statement," invoking the principle of "ALARA" -- "as low as reasonably achievable".

Exposure to children should in particular be limited, the recommendations said.

An interim European Union study released earlier this year concluded that cell phone use is unlikely to cause cancer, but said that the effects of long term use and on children are still unknown.

A comprehensive review of the potential health consequences of cell phone use -- known as the Interphone Study -- overseen by the International Agency for Research on Cancer (IARC) is set to be released before the end of the year, a spokeperson said Thursday.