http://www.boston.com/dailyglobe2/064/metro/Radar_tower_plan_rekindles_fearsP.shtml

President Bush's missile defense program seems highly technical and abstract, to be sure. But its real-world anchors would be five massive radar towers, each with thousands of antennas, most of which are already scanning the skies for aircraft and sea-skimming missiles.

One of them is on Cape Cod. The others are in California, Alaska, Greenland, and Britain.

Department of Defense officials confirmed that they are seeking to upgrade the 22-year-old PAVE PAWS early warning radar station in Sagamore to integrate it into the missile shield project.

''We want to be able to incorporate it, contingent on an environmental impact statement now underway,'' said Lieutenant Colonel Rick Lehner of the National Ballistic Missile Defense Office in Washington, D.C. That news is troubling to many Cape residents, who have long raised concerns about the health effects of the radar.

The 10-story, gray radar unit, shaped like a pyramid, is perched on Flatrock Hill at the Cape Cod Air Force Station, just past the Sagamore Bridge.

The unit, which is able to ''see'' over the horizon, protects the East Coast by casting a phased array radar beam, which emits low-level radiation, across the Cape and thousands of miles out to sea in search of air or seaborne threats.

''It does give some vividness to New Englanders that the system foreseen is a real one, and this installation would almost surely be a part of it,'' said Ashton Carter, a professor at Harvard's Kennedy School of Government and a former assistant secretary of defense.

PAWS stands for Phased Array Warning System; PAVE is an acronym for an older Air Force electronics and surveillance system. Unlike conventional radar, the 3,600 antennas on two of the unit's faces are set in fixed positions. But the beam can be rapidly projected in different directions by electronically controlling the phase, or timing, of the signals, allowing simultaneous tracking of objects.

The Air Force operates the Sagamore station, which uses about $100,000 in electricity per month, and has offered use of the radar unit for the missile program.

Military officials say residents' concerns about cancer risks from radar are unfounded and that they have overwhelming evidence to show that the unit is safe.

The Air Force is conducting a new health study at the request of local officials, however, including the Sandwich Board of Selectmen. That study is expected to take about one year.

Lehner said that the radar signal is below the safety limit for radio frequency emissions and that government studies have shown no adverse health effects from radar. He also said that the proposed upgrade to bring it into the missile defense system, would not increase the amount of radiation.

''We want to install new computers and new software to make the system faster and more up to date, but there will be no increase in power,'' he said. But opponents say that there has never been a study of the kind of phased and pulsed radar used in the PAVE PAWS station.

''Their assertion that it is safe is based on old information,'' said Richard Judge of Sandwich, a roofing contractor and selectman who says the military has never done an adequate health study of the phased and pulsed radar technology used by PAVE PAWS.

He noted that an Air Force mathematician and medical researcher, Dr. Richard Albanese, last year broke ranks with the military in saying that the PAVE PAWS beam is potentially dangerous.

Judge said hundreds of Cape residents have joined Cape Cod Citizens to Move PAVE PAWS, a citizens group his wife, Sharon Judge, founded three years ago.

''People are concerned because Cape Cod has some of the highest rates of cancer in Massachusetts,'' he said. ''We're asking, what is unique to the Cape that could possibly be causing this. And certainly PAVE PAWS comes to mind.''

From 1993 to 1997, nine of the Cape's 15 towns had breast cancer rates at least 15 percent higher than the rest of the state, said a staff scientist at the Silent Spring Institute in Newton.

Judge said previous Air Force studies were inadequate because they looked solely at the intensity of the beam, and whether it heated human tissue.

'What Dr. Albanese is saying is that there could be detrimental effects from the phasing and pulsing, because it involves so many different frequencies and makes the beam jump all over the place.''

Albanese, a doctor who works in an Air Force research lab in Texas, broke with his superiors last May after he noticed that a government report on PAVE PAWS did not include papers he had written, detailing his medical concerns. He could not be reached for comment last week.