From NPR News, this is All Things Considered. I'm Michele Norris.


And I'm Melissa Block. The suspicion that cell phones may be linked to brain cancer has percolated for years, but the vast majority of scientific studies have shown no association between the two. NPR's Allison Aubrey reports on why the question isn't settled and why a few doctors went to Capitol Hill today to push for long-term research.

ALLISON AUBREY: There are a lot of studies on short-term exposure to cell phones. The National Cancer Institute has reviewed more than a dozen of them looking for a possible link to brain cancer. They found little or no increased risk within the first 10 years of use. On top of that, at the very time when cell phone usage increased dramatically and phones became more powerful, from 1987 to 2005, there was no upturn in the incidence of brain cancers in the United States. Dr. Dimitrios Trichopoulos is a professor of cancer prevention at the Harvard School of Public Health. He says when you combine everything we know so far, there's no cause for alarm.

DIMITRIOS TRICHOPOULOS: It seems convincing that there is definitely no important increase, nothing that would make us very much worried.

AUBREY: British scientists have weighed in as well. Dr. Lawrence Challis headed up a government panel in England last year that reviewed 23 studies on cell phone use and health effects. Just like the National Cancer Institute, the panel concluded that radio-frequency radiation from cell phones poses no short-term health risk. They say the amount of radiation is just too low to cause harm. But Challis says among the few studies that included people who had been using cell phones for a longer time, more than a decade, there is uncertainty. Some studies identified a very low number of brain cancers among cell phone users, but it's just as likely those were due to chance as it is that cell phones played a role.

LAWRENCE CHALLIS: If you look at all the work that's been done, there are slight hints of something for people who use them for more than 10 years and some of the brain cancers, but they are not totally convincing hints. All they are is suggestions that we can't be sure there isn't something there.

AUBREY: Despite this uncertainty about long-term exposure, the British panel did not urge people to give up cell phones. Challis says people who are concerned have several options. They can text message, use headsets or earpieces, and they can limit use of their mobile phones by using landlines. The panel recommendations were stronger when it comes to children. The group, which called itself the Stewart Committee, advised parents to err on the side of caution.

CHALLIS: Children may be appreciably more sensitive to radio frequency, so I think the advice given by the Stewart Committee was that children really should be discouraged from using phones.

AUBREY: This advice to restrict children's use of cell phones was reiterated today during a hearing on Capitol Hill. Physician Ronald Herberman, who heads the University of Pittsburgh's Cancer Institute, made headlines last summer when he urged his faculty and staff to limit cell phone use. In testimony today, Herberman said he's not an expert on the risks of cell phones, but he said it's his opinion that they pose a larger risk for everyone than the current science sheds light on.

RONALD HERBERMAN: I cannot tell this committee that cell phones are definitely dangerous, but I certainly cannot tell you that they are safe.

AUBREY: Herberman and his colleagues are asking for help in their efforts to get cell phone companies to release billing records for future studies. This is the strategy already under way in a long-term European study. Lawrence Challis says it includes about 200,000 cell phone using volunteers and loads of documentation from their cell phone bills. This way, researchers won't have to rely on people's faulty memories about how much they gabbed five years ago.

CHALLIS: Most of these volunteers will have used their phones for about five to ten years previously. So you've then got a much better calibration of how much they used.

AUBREY: If lots of gabbing over time is predictive of any increased risk of disease, in five years or so this study will show it. Allison Aubrey, NPR News.

Copyright © 2008 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR’s programming is the audio.



Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.