The U.S. Court of Appeals, in a significant victory for the Labor Department, yesterday upheld strict rules designed to protect workers from exposure to dangerous levels of lead on the job.

In a 246-page opinion, the majority of the court turned away vigorous arguments from the lead industry and labor unions, which have opposed the rules from the day they were issued more than two years ago.

The ruling came in the wake of a U.S. Supreme Court decision last month striking down the government's standard for exposure to benzene. The high court said in that case that the Occupational Safety and Health Administration had improperly-based its rules on rigid assumptions about the danger of benzene, instead of coming up with specific evidence of its harms.

Writing for the appeals court, in yesterday's decision, Chief Judge J. Skelly Wright said the agency's work on the lead standard stood in "marked contrast" to the benzene standard. Wright said that OSHA had clearly met the Supreme Court's mandate by amassing "voluminous evidence" on the harmful effect of lead at certain blood levels and correlating those levels to lead content in the air.

Wright said that the agency had justified immediate application of its tough standards to industries where exposure to lead is the highest, including primary and secondary lead-smelting operations, battery manufacture, electronics, paint and coatings manufacture, and other industries where lead levels pose the greatest risk.

The court, however, told OSHA that it will have to reexamine the feasibility of applying those standards to industries where lead exposure is not as great, including auto manufacturing, shipbuilding and textile manufacturing.

Although the court postponed imposition of the standard in those industries, it did require that those manufacturers in the meantime protect workers' health through respirators to shield them from high lead concentrations.

Secretary of Labor Ray Marshall said in a statement late yesterday that he was "delighted" with the court decision, which he said will help protect tens of thousands of workers from lead-related damage to their health.

"I believe this decision is especially important and encouraging for the future of worker protection, and I'm sure my sentiments are shared by lead workers and their families across the country," Marshall said.

W. Scott Railton, Washington lawyer who represented the American Iron and Steel Institute and other industries in the court challenge, said yesterday that he expected the industry to seek further court review.

In November 1978, when the rules were announced, OSHA officials speculated that they could cost up to $300 million a year in capital and operating expenses.

Labor unions contended that OSHA had failed in its duty to assure that no worker's health would be impaired by lead exposure. The court, however, held that the lead standard set by OSHA was reasonable and rejected the workers' call for an even tougher standard.

The agency estimated that 835,000 workers are currently exposed to lead, a highly toxic substance which, when it accumulates in the body, can cause irreversible damage to the blood, nervous systems, kidneys and reproductive system.

The appeals court also upheld a portion of the rule that would require employers to remove workers from lead-exposure jobs, or reduce their work hours, if the content in their blood reached a certain level. If those actions did not reduce dangerous lead levels, the employer must lay off the employe but maintain earnings and seniority rights up to 18 months and restore the employe to his or her regular job when health improves.

OSHA had considered this so-called "medical removal protection" indispensable to its efforts to monitor lead levels in the workplace. Without it, OSHA theorized, workers would refuse to participate in the testing, fearing they would lose their jobs.

Chief Judge Wright was joined in his decision by Circuit Judge Spottswood W. Robinson III. Curcuit Judge George E. MacKinnon, in a 37-page dissent, protested among other things that the agency had improperly used private consultants during the rule-making process and that it had not conducted a proper hearing.

MacKinnon also felt that the medical-removal provisions improperly interfered with workmen's compensation laws and that OSHA, contrary to the majority's opinion, had not met the test set down by the Supreme Court in the benzene case.