(Xinhua/Agencies)
Updated: 2007-09-11 15:58

BEIJING -- Wireless identification tags planted beneath the skin may cause cancer, US media reports Monday cited medical studies as cautioning.

Wireless identification tags planted beneath the skin may cause cancer, studies suggest. [File photo]

The RFID (radio-frequency identification) chips, first implanted in pets, are small radio devices encoded with information about the animal and are meant to get them home safely if lost. The chips can be read with a remote sensor device.

Those chips are now being implanted in some people, especially Alzheimer's patients, and encoded with their medical records.

Some 2,000 people worldwide have had them fitted, and the companies which make them hope to see them installed in millions of patients for medical monitoring.

But a number of studies have found disturbingly large numbers of tumours in mice which were implanted with microchips.

Media reports said that studies in veterinary and toxicology journals published between 1996 and 2006 found that "chipped" laboratory mice and rats sometimes developed tumors under their skin, most of which encased the implants.

The studies cited include: a 1998 study in Ridgefield, Conn. of 177 mice that found an incidence of cancer that surpassed 10 percent; a 2006 study in France of 1,260 "chipped" mice that found tumors in 4.1 percent of the mice; and a 1997 study in Germany that found cancer in 1 percent of 4,279 chipped mice.

While the reports cautioned against using the findings to predict the effect of implantation on human health and noted that none of the studies included a control group of mice without implanted chips, cancer researchers nonetheless said the findings were enough to make them wary of RFID implants and did merit further research.

VeriChip Corp., which makes RFID implants, took issue with the studies. "Over the last 15 years, millions of dogs and cats have safely received an implantable microchip with limited or no reports of adverse health reactions from this life-saving product," the company said in a statement posted on its website.

VeriChip cited two studies that find no link between RFID implants and cancer in mice. "Since learning of the (AP) article, we have discovered two studies from our manufacturer... that examine microchip implants in laboratory mice and rats and conclude that microchip implants DO NOT cause malignant tumors."

"We recognize we have a corporate responsibility to review these studies, to look at other studies, to do new studies if necessary, and do what it appropriate after reviewing all of the information in all regards, and we intend to do this," said Scott Silverman, chairman and CEO of VeriChip, during an ABC News interview broadcast Monday.