A Circuit Court judge ruled here today that three Frederick County farm families suing a nearby aluminum smelter for damages from air pollution may not recover $3.2 million in punitive damages they had sought.

Judge Samuel W. Barrick, ruling on a motion by the defendant, Eastalco Aluminum, said that the jury in the air pollution case may consider no claim for punitive damages because there had been no showing of malice in the aliminum company's actions.

The families' claim for punitive damages had amounted to two-thirds of the total $4.8 million originally at stake in the trial. Still at issue is $1.6 million in actual damages that the farm families charge were caused by fluoride gas emissions.

Members of the families testified during the three week trial that smoke from the smelter rolled across their farms, damaging dairy cattle, trees and crops and causing the farmers to gasp for breath and wipe tears from their eyes.

Eastalco began its defense against the charges by the farmers yesterday with two experts -- a biochemist who has done extensive studies of the effects of fluoride on cattle and a professor of veterinary medicine who specializes in toxicology. Both men said that they had examined the three dairy herds in question and found that the cows' milk production had not suffered as a result of fluoride emissions.

Dr. John W. Suttie, a professor of biochemistry at the University of Wisconsin, told the jury "My opinion is that the ability to produce milk by these animals has not been impaired," nor had their ability to reproduce, he said.

Suttie, who said about 1 1/2 per cent of his research funding came from Eastalco, which is part of an industry group that finances fluoride research, said, however, that the cattle he examined showed damage to their teeth from fluoride.

The extent of the damage to the cattle's teeth is a major issue in the trial because serious damage may effect the animal's feeding habits and subsequent milk production.

Arguments over whether the farm families would be able to claim punitive damages focused entirely on whether there had to be a demonstration that Eastalco had acted maliciously.

Neither side contended that Eastalco had been malicious. "We have no proof that Eastalco actually intended to injure these plaintiffs," said their attorney Arden E. Shenker on Thursday. Shenker argued, though, that the company's failure to restrict emissions, knowing that emissions might cause damage, was grounds for punitive damages.

"Maryland does not favor punitive damages and they are only permitted within narrow limits," said the judge. "They are not awarded as means of compensation to the plaintiffs. They are assessed for reasons of public policy or in the interest of society," Barrick said.