A new warning about possible brain cancer hazards from cellphones' radiation is the latest caution about the handheld devices many Americans use daily. Last week's finding from a World Health Organization panel of 31 scientists is based on a review of many studies of low-level magnetic fields emitted by the handsets. The organization now ranks mobile phones devices alongside some dry cleaning chemicals and pesticides as a potential health threat. Its specialists didn't comment on how large or small the risk is.

Others see no cause for alarm. "When it comes to cancer, you likely face more danger going out into the sun than you do on a cellphone," Slate e-magazine technology columnist Farhad Manjoo wrote last Thursday. To be on the safe side, though some experts recommend an earpiece. "Just keep the phone away from the head," suggests Professor.Henry Lai, who studies electromagnetic fields at the University of Washington in Seattle.

Amid the debate, five states (California, Maine, New Mexico, Oregon and Pennsylvania) are considering laws to add cellphone package warnings. San Francisco already requires shops to post the radiation levels of every model sold, a step pending in several other cities.

Parent says: "Kids attached to their phones worry me. A lifetime of that cell phone usage, starting at age 10 or 11 now, is scary." -- Nancy Hanus, Bloomfield Hills, Mich., mother of 16-year-old

Tech columnist says: "Our worries about cellphones and cancer clearly aren't based on a rational analysis of their relative risk compared with other products we use." -- Farhad Manjoo, Slate.com

Study leader says: "We found some threads of evidence about how cancer might occur, but have to acknowledge gaps and uncertainties." -- Dr. Jonathan Samet of the University of Southern California, a National Cancer Advisory Board member