A U.S. Court of Appeals panel here ruled yesterday that the federal government has not adequately enforced a law aimed at protecting children in public housing units from the hazards of lead-based paint.

The three-judge panel ordered the Department of Housing and Urban Development to adopt tougher regulations to eliminate "as far as practicable" lead-based paint in areas accessible to children.

"Lead poisoning . . . is a serious health problem," Judge Edward Tamm wrote for the unanimous panel. About 200 children a year die from lead poisoning and as many as 10,000 others suffer significant adverse effects from lead poisoning, Tamm said.

HUD regulations require the elimination of lead paint only if the paint is loose or cracking. But the panel said the department also must try to eliminate lead paint that is intact or 'tight,' since children "can contract lead poisoning by chewing on intact lead-based paint," Tamm said in the opinion.

The panel, citing a June 1982 ruling by U.S. District Court Judge Gerhard A. Gesell, said the department's "complete failure to address the hazards associated with 'tight' paint containing lead is contrary to the intent of Congress."

Tenants at the Stanton Dwellings project in Southeast Washington who initiated the suit argued that HUD was not monitoring the D.C. Housing Department's compliance with current federal regulations on lead-based paint.

Tamm, joined by appeals judges Ruth Bader Ginsburg and Robert H. Bork, agreed that HUD had not fulfilled its duty to ensure that local housing authorities that receive federal funds comply with those regulations.

The tenants also objected to a HUD regulation that requires warnings about lead-based paint be given only to tenants and buyers of housing built before 1949. But the panel said a 1973 law gave HUD authority to decide whether to issue those warnings to tenants or buyers of housing built after 1949.