THE SURGICAL procedure is called a craniotomy, and Alan Marks says it is as frightening as it sounds. Nineteen months ago, his skull was opened to remove a golf ball-sized malignant tumor from the right frontal lobe of his brain in a seven-hour operation at UCSF Medical Center.

It had been growing there for years, he was told, before announcing itself May 6, 2008. That's when he had a seizure, flailing his arms, uttering unintelligible sounds and terrifying his wife, Ellie.

The Lafayette resident said he knows what caused it: extensive cell phone use.

Ellie and son Zack first wondered about the connection, researching Alan's condition online. She contacted international authorities on the correlation between cell phones and cancer, including Drs. Lennart Hardell of Sweden and Elihu Richter of Israel, who reviewed her husband's medical and cell phone history.

"They said absolutely, without a doubt, there is a connection," Ellie said.

Other experts will debate the conclusion, nonbelievers will dismiss it and those of us with no strong opinion will scratch our chins. In fact, we did that in this space 12 days ago, wondering about the dangers of the electromagnetic radiation that cell phones emit.

Alan and Ellie say we should be concerned. They have testified before Congress and the Maine House of Representatives, appeared on the "Dr. Oz Show" and national network newscasts. Numerous authorities share their opinion: Cell phones should come with a warning.

Alan, a 58-year-old real estate broker, said he used to be glued to his cell phone — more than an hour day, on average, for more than 20 years — always with the receiver tucked against his right ear. That last part is key, he said: proximity to the brain. Cell phones can be safe if they are kept at a distance — on speakerphone or headset.

"If there had been a warning 27 years ago, I still would have used a cell phone," he said, "but I wouldn't have put it to my head. That's the issue. People are killing themselves without being warned."

Because children and teens have thinner skulls, they are even more susceptible to microwave penetration, according to Cindy Sage. She is the co-editor of the BioInitiative Report, a study compiled by 14 doctors and health experts who analyzed cell phone dangers. An adult who uses a cell phone for 10 years or more has double the normal risk for malignant brain tumor. For those who start using cell phones as teenagers, the risk is five times as much, she said.

The question that you're asking is the same one Ellie Marks asked: Why doesn't the government require warning labels?

That was why she appeared before the U.S. House of Representatives in 2008, at the invitation of Rep. Dennis Kucinich, D-Ohio, where she was stunned to learn Congress had not addressed this issue since 1997.

The 1997 standards, still in effect, are based on thermal heating — the amount of energy required to burn human tissue. Radio frequency and microwave radiation can have major effects without heating anything.

"Not much came out of the hearing," Ellie said. "But our government knows there's a problem. And the industry knows it, too."

Cell phone manufacturers' only acknowledgment appears in fine print buried deep in owners guides. The iPhone 3G advises users to keep the device at least five-eighths of an inch from their bodies; the BlackBerry 8300 says it should be 0.98 inches away.

Why, Alan asks, aren't the warnings printed on the box?

"People will still buy them," he said. "They'll just use them more responsibly."

Major organizations such as the National Cancer Institute and the World Health Organization have declined to press the issue. They say there is no definitive evidence of a health threat, but don't tell that to Ellie.

"I've been contacted by hundreds of people with brain tumors," she said, "and they're all convinced it was because of cell phones."

Finland, Israel and France have guidelines for cell phone use. State Sen. Mark Leno, D-San Francisco, wants to do the same in California. San Francisco Mayor Gavin Newsom has urged that cell phone packaging print radiation absorption levels "as large as the price."

Meanwhile, Alan Marks has returned to work at Alain Pinel Realtors, painfully aware that his tumor could return. He occasionally is reminded of his cognitive deficits — lapses in concentration and difficulty conveying his thoughts — but he has no difficulty expounding on one topic.

"It bothers me to see people putting cell phones to their heads," he said. "They don't know what they're doing."

Contact Tom Barnidge at tbarnidge@bayareanewsgroup.com.