U.S. cell phone use has quadrupled in the past decade to about 280 million customers.
Meanwhile, brain cancer remains as rare as ever. A city the size of St. Petersburg can expect only about 20 new cases a year.
In December, two sources of popular health wisdom Prevention magazine and Dr. Mehmet Oz on his new TV show warned against cell phones and other devices that emit electromagnetic radiation.
We plaster cell phones right next to our skulls, they noted. Kids who text friends at night hide activated Nokias or LG's under their pillows, just inches from their developing brains.
Not to mention the doomsday scenario: What if symptoms don't appear for 20 or 30 years, as with smoking and lung cancer? Might a lethal invader already have its beachhead?
The Interphone study, a World Health Organization compilation of studies from 13 nations, is due out any day. Different countries found conflicting results, so authors struggled to craft a joint conclusion. But many observers predict that at the very least the report will include cautionary language about phones.
Reputable authorities like the National Cancer Institute and the Centers for Disease Control and Prevention have largely discounted a cell phone-cancer link. And most of the 13 country studies found little connection at least not to the "statistically significant" level that is academia's gold standard.
On the other hand, Israel's Health Ministry urged parents last year to restrict children's cell phone use after the study there indicated a rise in salivary gland tumors among heavy cell phone users particularly in rural areas where phones must pump out more energy to reach far-flung cell towers.
So need we worry about disease every time we dial? Or is the only real cell phone hazard that yahoo texting as he barrels down the highway?
Some of the earliest worries about cell phones blossomed in Pinellas County, when Madeira Beach resident David Reynard sued NEC and GTE in 1992 over his wife's brain cancer. Industry stocks nose-dived after he appeared on Larry King Live.
Electromagnetic energy from cell phones dissipates within a few inches, but that's enough if the antenna sits right next to your head, Reynard figured. Radiation of extremely high frequency like X-rays and gamma rays is a known carcinogen, he noted. Why not low-frequency cell phone radiation that bombards the brain for years and years?
A judge called Reynard's suit "junk science" and threw it out, but the brouhaha forced the cell phone industry to commit $25 million for safety studies.
Since then, scientists all over the world have looked closer. Usually, they asked people with brain tumors about their cell phone use. Results varied.
A 2006 German study indicated that the risk of glioma, a vicious cancer, rose 120 percent for people who used phones for at least 10 years.
A 2006 Swedish study suggested that 10 or more years of use raises high-grade glioma risk by 210 percent and way more often than not, people recalled holding their phones on the side of the head where the tumor showed up.
A 210 percent rise in brain cancers would mean that about 20 Americans out of 100,000 would get them, not devastating compared with other diseases, but a disturbing trend that presumably would accelerate over time if cell phones do cause cancer.
Interphone studies by Denmark, Norway, Finland, Sweden and the United Kingdom, on the other hand, indicated no particular rise in glioma after 10 years of use.