Reassuring Findings in Study of Cell Phone Use by Children

A Scandinavian study finds that children who used cell phones regularly were no more likely to have been diagnosed with a brain tumor than those who didn't use them but some scientists say an analysis of the underlying data reveals that the findings are actually "quite troubling."

As usual, the latest study's findings aren't black or white. In a small subset of patients, for whom the cell phone company had actual data, there was a correlation between tumor risk and the amount of time they had owned a cell phone.

The study included 352 patients ages 7-to-19 in Denmark, Sweden, Norway and Switzerland. Only 5 percent of the children and teenagers in the study had used cell phones for longer than 5 years.

When results for all durations of cell phone use were pooled together, researchers did not see a statistically significant elevation of brain tumor risk. However, this broad aggregation of the results masks important signals in the underlying data, cautioned Environmental Working Group senior scientist Olga Naidenko, Ph.D..

Notably, the researchers defined as “regular users” “all subjects who had an average of at least one call per week for at least 6 months.” As nearly every cell phone user would affirm, one call a week is an extraordinarily low, and hardly typical, frequency of use.

The underlying data reveals troublesome and provocative trends. The study found an elevated risk of brain tumors among children who had used cell phones longer than 2.8 years. Even more worrisome, when the scientists analyzed much more reliable cell phone use data obtained from the cell phone companies themselves, they saw a “statistically significant trend of increasing risk with increasing time since first subscription…”

“Given that in studies of adult cell phone users a statistically significant increase in cancer risk was observed only in those that looked at exposure periods of longer than 10 years, EWG finds it very troublesome that some elevation of risks for children and teenagers was observed from as little as three years” in the latest research,  Naidenko said. “These results should be of great interest to parents who want to take a precautionary approach to their children’s cell phone use.”

Effects on children

Health officials have grown increasingly concerned about the possible long-term effects of cell phone usage by children, partly because children's developing brains may be more susceptible to harm by radio-frequency emissions and partly because children are likely to be exposed to the emissions for many more years than today's adults.

Despite the lack of a strong correlation between cell phones and brain cancer in young patients, the researchers said they can't "rule out the possibility that mobile phones confer a small increase in risk" and called for future prospective studies. The largest such study now underway is the COSMOS trial, which will follow European cell phone users for 20 years.

In an editorial accompanying the study, two scientists from the International Epidemiology Institute, a unit of the National Institute of Health (NIH) in Rockville, Md., called the results “largely consistent and reassuring.”

The World Health Organization has declared that cell phone emissions may be carcinogenic.