Last month, Finland's Radiation and Nuclear Safety Authority joined agencies in Britain, France, India and Israel in warning that regular use of cell phones could damage children's brains. France and a number of other European nations are proposing to ban the marketing or design of cell phones for kindergarteners.

What do they know that we don't?

The amount of radio frequency that can be emitted by a cell phone is based on models of a man's head — not just your average Joe, but one who ranked at the top 90th percentile of all military personnel in 1988, totaling about 200 pounds.

Few parents know that radio-frequency signals reach much more deeply into children's thinner and smaller heads than ours — a fact established through the pioneering work of professor Om P. Gandhi, the leader of the University of Utah's electrical engineering department.

The agency that offers recommendations on cell-phone emissions in the U.S. — the Federal Communications Commission — doesn't employ a single health expert. The standards the FCC adopts are based on advice given by outside experts, many of whom work directly for the cell-phone industry. The Food and Drug Administration lacks the authority to set standards for cell phones and can only act if a phone is shown to release hazardous signals.

What's wrong with this picture?

The award-winning Gandhi worries that all the standards used for phones apply to the "big guy" brain. In 2004, standards became looser, because industry modelers decided to use a new approach — basically doubling the amount of radio frequency that could reach the brain of an adult and quadrupling that reaching a child's. The brain of a child doubles in the first two years of life and keeps on developing until their early 20s. Gandhi no longer works with the cell-phone industry and none of his grandchildren uses a cell phone.