Scientists are calling into question a study published last year that failed to find a link between cell phone use and brain tumors in children and teens. They say the study actually shows that cell phone use more than doubles the risk of brain tumors in children and adolescents.
The concerns come from the Environmental Health Trust, a group whose stated mission is to promote awareness of environmental issues they believe are linked to cancer.
In July 2011, the Journal of the National Cancer Institute published the first study on cellphone use and risk of brain tumors in children and adolescents, which was conducted by researchers at the Swiss Tropical and Public Health Institute. The scientists interviewed children and teens in Norway, Denmark, Switzerland and Sweden about their cell phone use and also collected cell phone records for a portion of them. Of the children studied, 350 had been diagnosed with brain cancer and 650 of them were healthy.
The July paper concluded that the data showed no link between cell phone use and brain tumors and "argues against a causal association" between the two.
In a letter published today in the journal, the Environmental Health Trust said the interpretation of the study's results was flawed and contained several statistical errors.
Lloyd Morgan, a senior research fellow at the Environmental Health Trust and one of the authors of the letter, called the study "sloppy" and said the data reported in the original study actually shows that children who used cell phones had a 115 percent increased risk of brain tumors over those who did not.
"There's every indication that this study actually found that children have a doubled risk of brain cancer," Morgan said. "For them to just state that we don't think there's a problem is, for me, quite mystifying."
Responding to the criticisms, Martin Roosli, author of the original study, said Morgan and his colleagues provided no explanation for the fact that rates of brain cancer among children and adolescents in Nordic countries have remained relatively stable for the past 20 years, despite increasing use of cellphones.
"And to be honest, since the funding of the Environmental Health Trust depends on donates, I would not call this independent," Roosli said.
In the original study, Roosli and his colleagues did note some limitations of their work, including that a relatively small number of children were studied. They also wrote that they could not "rule out the possibility that mobile phones confer a small increase in risk."
International concern over the potential health risks posed by cell phones has gone on for years. In May, the World Health Organization's International Agency for Research on Cancer put the devices in the same category as lead and engine exhaust, citing the possibility that long-term exposure to cell phone radiation could have long-term health effects. Roughly 30 studies so far have failed to draw a conclusive link.
In October, the Environmental Health Trust also criticized the test used by the Federal Communications Commission to measure cellphone radiation, saying the measure did not accurately reflect the radiation transmitted to children and adults while using cell phones.
Concerns over risks to children are particularly heightened, considering the rising use of cell phones among kids and teens and the fear that children's developing brains might be more susceptible to the effects of cellphone radiation.
However, only two studies so far have investigated the link between brain tumors and cell phone use specifically among young people -- one is the disputed study, and the other is a research project currently underway in 13 countries.
Joel Moskowitz, director of the Center for Family and Community Health at the University of California-Berkeley's School of Public Health, said current evidence showing a link between cell phone radiation and cancer risk is enough for him to say scientists should not dismiss concerns.
"You can't prove that it's cell phone radiation, but we certainly have a smoking gun," Moskowitz said.
Dr. Michael Thune, vice president emeritus of epidemiology and surveillance research for the American Cancer Society, said because cell phones are a fairly new phenomenon, no one really knows just what their health effects are yet, but he sees no evidence to support the concerns voiced by the Environmental Health Trust.
"The issue of whether cell phones do have adverse effects is an important one and needs further surveillance, but I don't find this particular letter to be very compelling," Thune said.
Experts agree that all cell phone users, regardless of age, can take steps to minimize any potential risks, such as keeping phones a moderate distance away from the head and body and using headsets or earpieces instead of placing the phone next to one's head.
Use a headset. RF waves are transmitted through the phone's antenna, so avoid placing the antenna against your head.
Use a landline phone when you can.
Minimize the length of your calls, or send an email or text.
Cell phones send out more RF waves when they are searching for a signal, so during those times, keep the device away from you or turn it off.
A little distance goes a long way. Doubling your distance from the phone cuts your risk by 75 percent.
Some manufacturers claim cell phone radiation shields can protect users from the effects of your cell phone's RF waves, but according to the FCC, the devices aren't proven to be effective. In fact, using these devices could increase your exposure to RF, because your phone has to work harder to overcome the physical barrier.