'Cellphones Don't Increase Kids' Cancer Risk' Study Flawed, Experts Say
Some experts believe a new study on the dangers of cellphone use among children and teens is misleading.
Credit: sxc.hu | apatterson

In the first ever study seeking connections between cellphone radiation and brain cancer in children and adolescents, researchers said they found no evidence of an increased cancer risk in young people who use cellphones.

Sounds like good news; however, the paper, which was published in the July 27 issue of the Journal of the National Cancer Institute, has many scientists up in arms. Not only do they contend that the study design is flawed, they say the authors' conclusion — that cellphones don't cause brain cancer in children — isn't supported by the results.

"It's a very peculiar paper and even more peculiar that it's published in a journal sponsored by the National Cancer Institute," Joel Moskowitz, director of the Center for Family and Community Health at the University of California-Berkeley, told Life's Little Mysteries. A red flag, he said, is that the research was funded in part by the cellphone industry, and some of the investigators also do other industry-funded research.

In Moskowitz's opinion, the conclusions drawn by study leader Martin Röösli, an environmental epidemiologist at the Swiss Tropical and Public Health Institute, and his colleagues were biased to downplay concerns about cellphone use among children and adolescents. [Countdown: 5 Everyday Things that Are Radioactive]

Devra Davis, an epidemiologist, president of the Environmental Health Trust and former senior advisor to the World Health Organization (WHO), felt similarly. "This new JNCI report represents an astonishing, disturbing and unwarranted conclusion," she told the media. Lloyd Morgan, an electronics engineer who studies the effects of electromagnetic radiation with the Central Brain Tumor Registry of the United States, concurred. "They contradict their own conclusion, when you read the paper. It isn't what the abstract says it is," Morgan said.

The study seems biased, they say, despite the fact that the authors disclosed their funding sources and stated that they did not reveal their results before publication.

The new research compared cellphone use among 356 children (ages 7 to 19) who already had brain cancer with 646 control subjects (who did not have brain cancer) in four Northern European countries between 2004 and 2008. It reported an overall 36 percent increase in brain tumors for "regular" cellphone users — defined as those who used a cellphone at least once a week for six months. However, Röösli and his colleagues said that bump was not statistically significant. "A relative risk of 36 percent may sound high. But in absolute terms it means one additional case per 100,000 mobile phone users per years," Röösli explained in an email.

The connection between cellphones and brain cancer is not fully understood. WHO describes cellphone radiation as "possibly carcinogenic," and urges further study. Original research and reviews of past studies have led Davis, Moskowitz and Morgan to independently conclude that the radiation is carcinogenic. Regarding the new study, the experts aren't convinced that the risk to children is as slight as the conclusions suggest.

Watered down

In a response sent to the media, Moskowitz pointed out what he considers several flaws in Röösli's logic, starting with how little cellphone use (one call per week) counted as "regular." This parameter flooded the pool of truly regular cellphone users with almost-non-users, he said, skewing the results. "Such a loose definition of regular use would be expected to reduce the association between cellphone use and tumor risk," Moskowitz wrote.  [FAQ: Cellphone Radiation and Brain Cancer]

When a subset of the data corresponding only to heavy cellphone users is analyzed, he pointed out, the results become much more striking. From the journal's paper itself: "[There] was a highly significant association between the time since first subscription and brain tumor risk. Children who used cellphones for at least 2.8 years were more than twice as likely to have a brain tumor than those who never regularly used cellphones." The authors went on to state: "As compared to never regular users, those who used cellphones for 4 or more years based on phone company records were 3.7 to 4.0 times more likely to have brain tumors, and those who made 2,638 or more calls were 2.9 to 4.8 times more likely to have brain tumors."

However, the authors chose to disregard these findings, as they pertained to only subsets of the data, Davis said. "The JNCI researchers downplay their own finding that children who owned phones the longest had an increased risk of brain cancer," she said.

Time lag

The experts called into question another aspect of the research — its analysis of short time frames. "Brain tumors can take 10 years to form, and young children certainly have not been heavy cellphone users for very long," Davis wrote. "If you asked whether people who had smoked only four years had an increased lung cancer risk, you would come up empty-handed.  Given the restricted time frame of the JNCI study, the absence of brain tumor risk from cellphones in children and adolescents is precisely what is expected."

Furthermore, data collected from 2004 to 2008 is outdated, she said. "There has been a quadrupling of cellphone use in the past few years that this study could not possibly capture."

According to Davis, the JNCI editorial that accompanies Röösli's paper was written by scientists directly associated with the cellphone industry. Its affirmation of the conclusion that children face no risks from cellphones "does a profound disservice to the public," she wrote. When contacted, the JNCI spokesperson and executive editor both declined to comment.

Ultimately, all the scientists involved, including Röösli and his co-authors, called for further research on the link between cellphone use and brain cancer, and advised people to use cellphones with caution.

"My bottom line is that we have to clean up this field, and fund independent researchers who have no association with the industry," Moskowitz told Life's Little Mysteries.

Davis is the author of "Disconnect" (Dutton 2010), a critically acclaimed book on the dangers of cellphone use, and the ways in which she says the cellular industry has tried to cover those dangers up in order to stave off regulation. Moskowitz advocates an annual fee of 50 cents on all cellphones to go toward funding independent research on the health effects of electromagnetic radiation.

This article was updated on 7/29 at 2:20 p.m. ET to remove Moskowitz' claim that the journal JNCI is funded by taxpayers; the journal used to be sponsored by the National Cancer Institute, a taxpayer-funded government organization, but is now owned by Oxford University Press.

This article was provided by Life's Little Mysteries, a sister site to LiveScience. Follow us on Twitter @llmysteries, then join us on Facebook. Follow Natalie Wolchover on Twitter @nattyover.