When Sophia Stone discovered last month that a railroad company wants to build a microwave radio communications tower about 800 feet from her home in Franconia, she decided something had to be done.

Stone and some neighbors, calling themselves the "Concerned Citizens of Franconia," circulated in the community 2,500 fliers opposing the microwave tower, claiming there are unkown health dangers. They also claim the 240-foot tower will be an eyesore and hurt their property values.

Carson Lee Fifer, an attorney for the Richmond, Fredericksburg and Potomac Railroad, whose application to build the tower comes before the Fairfax County Board of Supervisors for approval Monday, says residents are overreacting. "We don't see any radiation problems," Fifer said.

The issue has the company and residents on opposite sides of a controversy that has created troubling and unanswered questions among scientists and government officials. Do microwaves at relatively low intensities pose a health hazard to the public?

Most American scientists familiar with this field say that studies are inconclusive as to the dangers of microwaves at low intensities. A recent study of Americans who worked at the American embassy in Moscow when the Soviet secret police beamed microwaves at the building show no apparent ill effects from the microwave bombardment.

"You don't know what can happen in 20 years," said Dottie LeFoy, whose recently purchased home is within 1,500 feet of the proposed tower. She said too little is known about microwave radiation to allow the tower to be built in the community.

"We don't want to get involved in a situation where they (the RF&P Railroad) were wrong," said Father Austin Ryder of St. Lawrence Catholic Church, which is 3,000 feet from the tower site. Ryder said he sent letters to nearly 1,000 parishioners, urging them to voice their opposition to Lee District Supervisor Joseph Alexander, in whose district the tower would be built.

Alexander told a group of 150 residents who gathered at St. Lawrence Catholic Church this week that he plans to ask the county supervisors to defer a decision on the microwave tower for at least 60 days. He said the extension is needed so the company can provide the conuty with additional information and look at possible alternatives.

Alexander's announcement was greeted with applause and cheers from the residents, many of whom have lived in the Franconia community for more than 50 years.

Lawyer Fifer said what the residents want is for the company to say that "there's no way the system will harm you. They (the company) can say it to the best of their knowledge. But, there is no way they can promise them. We can't prove a negative."

He said the company consulted two experts in the field of microwave radiation research and a scientist for the Environmental Protection Agency all of whom agreed that the tower's low intensity would pose no health hazard.

Norbert N. Hankin, an environmental scientist for EPA, said the tower radiation is less than one microwatt per square centimeter, considerably less than the U.S. occupational safety standard.

Fifer said the microwave tower, which the company plans to build about 3,000 feet north of Franconia Road at its intersection with Fleet Drive, is part of a $1.6 million communications project between Northern Virginia and Richmond.

The new system, which is expected to provide greater control and greater safety for all trains using the RF&P line, would replace the communication system now carried by large cables on telephone poles.

Fifer said four microwave towers in less populated areas south of Fairfax already have been approved. He said the company plans to resubmit to Alexandria officials proposed sites for microwave towers in their city. Proposed sites in Alexandria were submitted to officials earlier, but Fifer said they were withdrawn until the company could get the site approval in Fairfax.