Why Cell-Phone Health Concerns Persist

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Studying Tumor Risk

In February of this year, Japanese scientists participating in Interphone published partial findings, based on their research, in the British Journal of Cancer. They "observed no increase in overall risk of [tumors] in relation to regular mobile-phone use among our Japanese subjects."

While some experts hailed the research as providing evidence that mobile phones do not cause cancer, others dispute the conclusion. Bruce Hocking, an Australian doctor who specializes in occupational and environmental medicine, argues that the Japanese study had key flaws. In a letter to the Journal, Hocking said the Japanese gathered data that relied on people's ability to remember "cumulative length of use and cumulative call time," which "may be associated with random errors, leading to overestimation or underestimation of true usage." This is referred to as recall bias.

"It is hard for people to recall, accurately, their phone use over a 10-year period. Researchers want mobile-use records, but they are challenged by privacy rules," says Hocking. "The best way to research it is, prospectively, off billing data."

Closed Research Labs

But new studies on health and cell phones are tough to get going. In the U.S., most research on the topic was discontinued at the beginning of the decade, largely because industry groups and government considered the questions resolved and haven't been willing to finance new studies. "The U.S. had been the leading country in the research on radio-frequency radiation from the 1960s to the 1990s," says Dr. Henry Lai, a professor at the University of Washington who has studied research funding of the issue. Over time, however, "most labs in the U.S. that did research on electromagnetic fields closed down."

But scientists are concerned that cutting off studies could be a mistake. "It was 15, 20 years after people began smoking that we saw concerns associated with it," says Dr. Michael Kelsh, principle scientist and epidemiologist for Exponent, a scientific consulting firm. "Down the road, the same could happen with phones." He says that studying cell-phone usage requires time, because the latency period for brain tumors can be 10 to 15 years.

Dr. Michael Thun, vice-president of epidemiology and surveillance research for the American Cancer Society agrees that time is a concern, particularly with children using cell phones. "We haven't had long-term exposure with kids. There can always be surprises; we cannot say with 100% certainty that it is safe. It is just not clear yet."

Despite the ongoing concerns, Slesin cautions that people need not live in fear. "People should wear wired earpieces," he says. "I don't think people should stop using cell phones. I think people need to be aware that there is a risk."

Yarow is a reporter for BusinessWeek.