Debbra Wright, a real estate manager for a cellular phone company in Phoenix, used to live by her portable telephone. Now she has a brain tumor and contends the hand-held models she used daily for six years are responsible.

Susan Reynard of St. Petersburg, Fla., died from brain cancer. A judge dismissed a suit blaming the makers of her pocket phone, citing a lack of scientific evidence. But her husband is not convinced. He notes that his wife's tumor formed on the side where she had held the phone.

From a Hollywood agent deal-making at poolside to a woman stranded alone with car trouble, some 12 million Americans rely on portable cellphones, with more than a half-million new subscribers signing up each month.

At least eight lawsuits blame health problems on cellphones; none of them have come to trial.

"Do you know what it's like to . . . have your health go away?," asked Wright, 42, who has undergone multiple surgeries for her benign tumor. "It's been very hard to have pain 24 hours a day."

The first suit, filed by Reynard's husband in 1992, temporarily turned the emerging industry upside down. Users wondered if they were facing a hazard with each call. Cellular stock prices fell.

Manufacturers rushed to proclaim cellulars risk-free, although they were later taken to task by the Food and Drug Administration for saying thousands of studies over 40 years showed the phones safe.

In fact, most of those studies did not directly look at cellphones. And most of the current research to determine if the phones are dangerous is coming from a $25-million trust fund financed by the cellular industry itself.

Unlike car phones with antennae mounted outside the vehicle, hand-held cellulars like those in the Reynard and Wright cases have antennae that sit flush with the head, exposing callers to an electromagnetic field whose long-term effects remain a mystery to scientists.

"We don't have enough information to say the phones are harmful. At the same time, we really don't know enough to say they're not harmful," says Elizabeth Jacobson, deputy director for science at the FDA's Center for Devices and Radiological Health. "I think if there is a risk, it's probably small."

Dr. Ross Adey of the Loma Linda Veteran Medical Center--who is conducting cellular research funded by Motorola Inc., the world's largest manufacturer of cellphones--is worried by industrial studies linking other types of microwave exposures to cancer.