By Janet Raloff

Web edition: September 14, 2009

For cell phone users – all 4 billion worldwide – a Senate hearing today elicited some observations that should give pause. Such as that the risk of certain brain tumors may increase among people who have been heavy cell-phone users for a decade or more. Or that the type of radiation emitted by cell phones can, at least in cellular studies, damage DNA. Or that children have become major users of cell phones and that the radiation emitted by those devices penetrates further into their brains than into their parents’.

To date, most studies on cell-phone health effects have emerged from studies conducted overseas. Where have American researchers been during all of this? Probing that was the first order of the day at this afternoon’s hearing before a Senate Appropriations subcommittee.

The U.S. Food and Drug Administration nominated cell-phone radiation for carcinogenicity studies by a sister federal agency. That sibling – the National Toxicology Program (administered by the National Institute of Environmental Health Sciences) – is now undertaking such tests, noted John Bucher, NTP’s associate director.

Today, he outlined the three-pronged attack by which NTP is investigating potential health hazards, including cancer, from cell-phone use.

“While the current scientific evidence has not conclusively linked cell phone use with any health problem,” he noted, “we and other scientific organizations believe better data are needed to establish any potential risks to humans from the low level radiofrequency radiation associated with their use.” Indeed, he noted, the ubiquity of cell phones today “could translate into a significant public health problem should their use even slightly increase the risk of adverse health effects.”
 
How many Americans converse wirelessly? Only some 270 million, he reported. And while some early studies that probed for harm found none, he said that “There’s been some hints, recently, that there is an increase in brain cancers in people who’ve used these cellular communication devices for a number of years.” As in 10 or more years.

During their questioning of Bucher, Sens. Tom Harkin (Dem.-Iowa) and Arlen Specter (Dem-Penn.), suggested the current federal research program investigating possible harm from cell-phone use appears anemic. Its funding needs bolstering, they suggested. It should focus more on human studies, they implied, and it should identify which studies had industry funding (presumably because such industry influence might have colored analyses of the data).
 
For his part, Bucher said research on the issue was moving ahead as well as might be expected, based on its limited funding. He described a host of federally financed programs now underway. Chief among them, new rodent studies at the Illinois Institute of Technology in Chicago. They're using 21 chambers, each the size of a walk-in closet, to expose unrestrained animals to cell-radiation frequencies for up to 20 hours a day and throughout periods of up to two years.

These big new cages are significant, he said, because most earlier, European studies exposed restrained animals and for only two hours a day. Research in other fields have shown that restraints can impose stress. So there’s reason to question whether responses to any radiofrequency radiation might have been affected by that stress.

For NTP’s new studies, scientists at the National Institute of Standards and Technology have helped design the rotating antenna system, provided within each shielded chamber, to generate statistically uniform fields in the frequency bands used by cell phones – either 900 or 1,900 megahertz.

Male and female mice and rats will get zapped – including pregnant animals – to evaluate impacts at all life stages from gestation through the rodents’ golden years, Bucher explained. Chronic toxicity tests will begin late next year, with peer-reviewed analyses of their findings expected by 2014.

Researchers at five universities are also getting federal funds to study potential environmental triggers – including cell-phone radiation – of meningiomas. Usually noncancerous, these tumors develop in membranes surrounding the brain and spinal cord. At the University of California, Los Angeles, other scientists are probing data from a study of more than 100,000 Danish children exposed to cell-phone radiation. Here, scientists are scouting for non-tumor effects, including seizures, migraines, sleep disturbances and behavioral problems.

Harkin, who chaired the hearing, observed that European researchers had taken the lead in studying human impacts of cell technologies, such as through their participation in a big INTERPHONE Study. Asked Harkin: Why wasn’t the United States a part of this huge trial looking for cell phone affects in children and adults?
 
Bucher said the National Cancer Institute has provided at least some INTERPHONE funding, so the U.S. research community has played a role. But Harkin pointed out that the United States was not among the list of 13 participating countries, suggesting that any U.S. role had been too insignificant to mention.
 
Specter probed the issue a little further, asking shouldn’t U.S. scientists undertake more human studies on this issue?

“I certainly would suggest that there should be studies on humans, yes,” Bucher replied. Wouldn’t that cost more than NIH has allocated for cell-phone studies? “I believe it would,” Bucher told the senator.

Could Bucher supply the subcommittee “a recommendation of what sort of studies you’d recommend for humans and what the cost would be?” The NTP official told Specter he could, but not on the spot. Fine, Specter said: “Do it as soon as you can.”

Some of us who are not experts on how cell signals are affected by environmental conditions might have learned something from the senators’ further questioning of Bucher. For instance, Specter said he’d been briefed that cell phones should not be used in elevators, subways, or other places where reception is weak or blocked. True, he asked?

Yes, Bucher responded, “because the power that is used to reach the cell base station is higher in those situations.” And even if the cell signal doesn’t get through, Bucher says, radiation exposures can still be elevated in these environments “because the cell phone is still attempting to reach the base station.” Bucher showed a little uncertainty in explaining all this, which Specter picked up on. So the senator asked Bucher in a rather emphatic tone to follow up and “give us a more definitive answer.”

Actually, the senators should have invited some of the engineers among Science News' readership to answer the latter questions, not someone trained as a biochemist and toxicologist. And presumably, at some later date, they will get radiofrequency gurus to testify. Both Harkin and Specter indicated that cell phones – and how to limit radiofrequency radiation exposures to users – was a topic they wished to pursue further.