The Arlington County Board yesterday passed on ordinance banning smoking in a wide variety of public places including large food and retail stores, libraries and meetings attended by more than eight persons.

The ban, which went into effect immediately, passed after two hours of debate by a 3-to2 vote. Under Arlington's ordinance, which is patterned after similar laws passed last year in Fairfax and Montgomery counties, violators would be subject to a $25 fine.

Under the new law smoking is prohibited in elevators, health care facilities including doctors' offices with certain exceptions, theaters, art galleries, public and private schools and stores with more than eight employes.

Restaurants are exempt from the ban as are offices or work areas not entered by the public and theater lobbies and specifically designated smoking areas. Smoking in indoor recreational and cultural facilities supported by publicfunds is banned.

A much more stringent ban that would prohibit smoking in most public places not under federal control has been passed by a committee of the D.C. City COuncil, and will come up before the full council next month. If passed then it would be subject to congressional review.

About 30 people, most of them supporters of the new Arlington law, attended the hearing and about eight of them urged the board to adopt the ban. Physicist James Repace gave a 15-minute presentation on the hazards of smoking, complete with color slides of cancerous lungs.

Several other speakers said that because of their allergies to smoke they must drastically curtail their activities. But a Tobbaco Institute lobbyist called the law "unreasonable, unfair and unenforceable" and that tobacco smoke may be annoying to nonsmokers but is not a health hazard.

Board member Walter L. Frankland Jr., who voted against the law, said he thought it was unenforceable and suggested that the county print signs saying that the board had passed a resolution against smoking.

He was joined in voting against the ban by board member Joseph S. Wholey who said, "I haven't seen evidence that smoke in the air (is) harmful to nonsmokers' health." Voting for the ban were Board Chairman John W. Purdy, Vice Chairman Ellen M. Bozman and board member Dorothy T. Grotos.

Before the meeting began at 8 a.m., more than 300 county employee, many of them carrying picket signs, demonstrated in front of the county courthouse in protest of the board's decision to grant a 5 percent salary increase, instead of a higher figure.

County Manager W. Vernon Ford and School Superintendent Larry Cuban have both recommended 7 percent pay raises for the county's 2,500 employes, which is what employes say they want. A 7 percent increase would cost the county roughly $5.2 million.

Although the County Board will not adopt a budget until May 13, its members voted at recent work session to limit the raise to 5 percent, a saving of $1.5 million in comparison to the cost of the 7 percent the employes want. Last year the board granted raises ranging from 2 to 5 percent.

A coalition of county employes, which included uniformed police officers, firefighters, maintenence workers and teachers, marched in a circle chanting "More money, less work," before crowding into the board room and outer hall to listen to their representatives address the board.

Several speakers said they were particularly angered by Frankland's recent statement that employes who were dissatified with the proposed pay raises should get other jobs.

"Arlington's public employes have been waging the battle against inflation involuntarily," said Arlington Education Association president Lee Vosper. "A five percent increase is an unspeakable insult."

Other teachers said they were being priced out of Arlington, where the median income is $18.500, which is slightly lower than the average teacher's salary.

"I think somebody has to speak for the taxpayers," said board member Wholey, as employes shouted "That's us" and "We're citizens." He continued, "New York City was brought to its knees because it was in the grip of powerful employe unions." Last year the Virginia Supreme Court struck down a statue permitting collective bargaining by public employes.

Wholey, a fiscal conservative who sometimes votes with Frankland and Grotos on budget matters has said that Arlington's salaries are commensurate with area jurisdictions. He has said repeatedly that he favors using the county's expected $4.6 million surplus toward a 3-cent real estate tax cut and capital improvements such as bike trails and park development.

As employes filed out of the room one man started singing, "Good Bye Frankland" to the tune of "Good Night Ladies." Other emp loyes joined him in a spirited chorus as Frankland sat grim-faced.

After the meeting Wholey, Frankland and Grotos said they planned to vote for the 5 percent increase on May 13. Board Chairman Purdy and Vice-Chairman Bozman have said they support 7 percent increases.

Grotos, who had unsuccessfully proposed giving employes a range of increases, said of the demonstration, "When my children have a tantrum, I ignore them."