BALTIMORE – In what could bolster an $800 million lawsuit against Motorola and major cell phone carriers, a new study found a possible link between older cell phones and brain tumors.

Although many studies have found no cancer risk from cell phone use, the research published in the latest European Journal of Cancer Prevention said long-term users of analog phones are at least 30 percent more likely than nonusers to develop brain tumors.

Newer digital phones emit less radiation than older analog models of the sort studied.

The lawsuit against cell phone manufacturer Motorola was brought by Christopher Newman, a Maryland doctor stricken with brain cancer. A federal judge is expected to decide by month’s end whether the case should go to trial and if so, whether the study can be used as evidence.

“From our perspective, and from a public health perspective, the court should just be aware of what’s out there,” said Newman’s lawyer, John Angelos, whose firm has made millions suing asbestos and tobacco companies.

If the case is allowed to go forward, it could open the door to other major lawsuits against the wireless communication industry. So far, no similar claims have been successful.

Motorola attorneys criticized the methodology of the new report, which was written by Swedish oncologist Dr. Lennart Hardell.

Hardell studied 1,617 patients with brain tumors and compared them with a similar-sized group of people without tumors. He found that patients who used Sweden’s Nordic Mobile telephones were 30 percent more likely to have brain tumors, especially on the side of the head that touched the phone most often. Those who used the phones longer than 10 years were 80 percent more likely to develop tumors.

Newman’s lawsuit names Motorola, Verizon and other wireless carriers. He claims the analog cell phones he used from 1992 to 1998 caused him to develop a cancerous brain tumor behind his right ear. The tumor was removed, but Newman is blind in one eye, suffers memory loss and slowed speech and can no longer work, his lawyers say.

Cell phones are used by 97 million Americans. Digital phones emit radiation in pulses; older analog varieties emit continuous waves. By the time cell phones exploded in popularity in the late 1990s, most of those sold used digital technology.

Three major studies published since December 2000, including one by the U.S. National Cancer Institute, found no harmful health effects from cell phones.

Motorola spokesman Norman Sandler questioned the author’s theory that tumors are more apt to develop near the ear that touches the receiver most often.