Roscoe Bartlett says that after an asphalt company and a cement plant moved next door to his 150-acre dairy farm here several years ago, the leaves on his trees started turning black and his farm equipment began rusting through.

He blames the hydrocarbons in the air from the nearby Tamko Asphalt Products plant and the fine cement dust and lime from the Coplay Cement Co. Smelting chemicals also drift from the Eastalco Aluminum Co. near the town.

Frederick County officials say the three firms alone provide 1,259 jobs. The county is currently considering zoning changes to encourage even more industrial development in the southern county near here. But some residents of Buckeystown contend that the five plants already in their area constitute a nuisance and possible health hazard.

Under consideration by the county commissioners is a comprehensive plan calling for 50 percent of the county's industrial development to take place along the Rte. 85 corridor, most of it near Buckeystown.

Fifteen light manufacturing and technology firms are currently located along the corridor, with another 20 manufacturing facilities near the Frederick airport. Most of those facilities are located away from residential areas, however, and are not considered controversial, said county planner Jim Shaw.

Recently about 100 of Buckeystown's 350 residents met with county planners to express their opposition to the zoning proposal. And in a letter to state health officials, residents charged that the county commissioners "have done nothing to enforce air pollution laws."

The residents said that "foul-smelling odors" from existing plants have "spoiled our environment and threatened property values."

Frederick County health officials say Tamko, Coplay and Eastalco have all been cited for violating air, noise and water pollution standards. The Health Department monitors the firms on a routine basis and reports violations to the state, which must then decide whether to take action. State officials said that in the past, all three firms have corrected violations without state intervention.

Tamko officials acknowledged that the facility has been cited. But, general manager Robert Bard said: "We are now complying with every federal regulation, have spent a half-million dollars to control pollution at the plant, and we wouldn't do anything to harm the people of Buckeystown."

He said that in his "opinion the plant just smells like a new road. Don't forget farms have a way of making funny smells too," he said. "Unfortunately, you can't put a pollution-regulation device on a pig."

But George Ferreri, director of the State Air Management Administration, said that recently "pollutants have been observed beyond Tamko's property lines." He said the air-control device at the plant "doesn't seem to be working" and said the state "will be taking some form of action in the near future."

Ferreri said the Eastalco and Coplay plants are complying with state air-emission standards.

According to county sources, one county health official warned in 1978 against allowing Tamko to build there after visiting the company's Tuscaloosa, Ala., plant. In a memo, the official urged that county commissioners block plans for a Buckeystown plant because of potential air pollution problems. But permission was granted, and Tamko began producing asphalt in a plant on 185 acres of former farmland.

The resulting asphalt smell is so strong at night that they must shut their windows and stay indoors, neighbors say.

A few miles from Buckeystown is the Eastalco aluminum plant. Three weeks ago, Maryland health officials issued a permit allowing the firm to dispose of brick laced with cyanide and flouride in a landfill in Adamstown. Residents of that town maintain that the dumping may contaminate drinking water there.

In 1978, three families were awarded $65,000 after charging in a suit against Eastalco that their cows were poisoned with fluoride gases from the plant.

Eastalco official said this week they are complying with federal emission laws. Although the plant has been cited for "smoke problems" in the past, officials said, those problems have been corrected.

Roscoe Bartlett, a physicist who turned gentleman farmer 21 years ago, said he and his neighbors were unable to persuade county commissioners not to allow zoning for the asphalt company and the cement plant, whose giant smoke stacks can be seen from his front porch.

"I had dreams of owning a beautiful farm looking out at the mountains," Barlett said. "Now I look at smoke stacks--and there are bulldozers there waiting to build more."

Another Buckeystown resident, Lois Noffsinger, said in a town meeting last week that she would like industrial development stopped.

"We are farmers, but how long we can stay farmers depends on how the commissioners feel about us," she said, to applause, at the Buckeystown Methodist Church. "Technology is now upon us, and money talks. Now the county has put in water and sewerage for those industries, and the die is cast."

County commissioners must take action on the plan by September.