Some Alki neighbors share a growing concern about the planned installation of more wireless phone antennas on a three-story apartment building near Alki Point.

Cingular Wireless wants to expand its rooftop "base station" by replacing two antennas and installing four new ones on the roof of the Sound Crest apartments near the western end of Admiral Way. Four new equipment cabinets would be installed on the ground.

Meanwhile Verizon Wireless also wants to expand its base station on the roof of the same building. The company currently has three panel antennas there and is seeking city permission to install eight more.

Currently there's a large antenna on the southern portion of the apartment building roof. A cluster of shorter antennas at the northern part of the roof is surrounded by black-and-yellow-striped warning pylons.

Wireless base stations produce electromagnetic radiation as they transmit and receive signals from cell phone users. At high-enough levels, "radiofrequency radiation" can damage human tissue, just as a microwave oven heats food by raising the temperature of water captured in the food. But the Federal Communications Commission, which regulates the wireless phone industry and licenses television and radio stations, claims wireless communications use radiofrequency levels too low to pose a danger to humans.

Dr. Jim Borrow is a radiologist who lives near the Sound Crest apartments. He acknowledged there is scant scientific evidence that the levels of radiofrequencies typically used in wireless communications would cause immediate harm to anyone. Although brief exposure to such energy might not pose a health threat, he is concerned about the possible cumulative effects.

When X-rays were first being used in diagnostic medicine, Borrow said, radiologists weren't particularly concerned about exposing their hands to the rays as they positioned patients and worked with the equipment. But when the use of X-rays had been commonplace for 15 to 20 years, radiologists started losing fingers, he said.

Panel antennas like those planned for the roof of the Sound Crest apartments typically measure about 1 foot by 4 feet. They are arranged in three groups of three antennas each, according to information on a Federal Communications Commission website. One antenna in each grouping transmits signals to wireless phones while the other two antennas receive signals from wireless phones.

The signals travel at the speed of light toward the horizon in a narrow, line-of-sight pattern.

Base stations have to be installed in high places such as on towers, water tanks, poles and rooftops. Across the nation, wireless phone towers stand anywhere from 50 to 200 feet tall, states the Federal Communications Commission.

Hudson Burke, an Alki native who's worked in the field of electromagnetics, also is worried about the unknowns of wireless communications.

"There could be an health issue if you have a dense antenna farm in a single-family neighborhood and next to Bar-S Field (a city park with baseball diamonds next to the Sound Crest apartments)," Burke said.

The city of Seattle has no jurisdiction over the safety of wireless antennas. But the city can decide whether the air-conditioning units used to cool the wireless equipment would be too noisy, said Karen Clegg, another Alki neighbor worried about the electronic rooftop additions.

The residents also have been concerned about the veracity of information supplied on applications for the project to the Seattle Department of Planning and Development. They obtained a copy of one of the completed application forms, which asked if there are any public parks near the site. The answer given on one application stated "none known" even though Bar-S Playfield is right next door.

City officials asked for additional information from the cell phone companies as they ponder the expansion request.

Tim St. Clair can be reached at timstc@robinsonnews.com or 932-0300.