A 15-year-old federal program designed to inform the public about the health hazards associated with cigarette smoking has largely failed, and tougher warnings on these risks are needed in cigarette advertising and on cigarette packages, the Federal Trade Commission staff warned yesterday.

The FTC staff, in a report five years in the making, indicated, for example, that more than 30 percent of the public is unaware of the links between cigarette smoking and heart disease. In addition, the study said that nearly 50 percent of all women do not know about the risks of smoking during pregnancy.

Reports from the Surgeon General and other medical sources indicate that smoking during pregancy is hazardous to the child. One study cited by the FTC indicated that pregnant women who smoke heavily increase the risk that the unborn child will die near the time of birth by 35 percent.

The FTC staff charged that the cigarette industry, which the agency said is the nation's most heavily advertised, "does not disclose material health and safety information" in its advertising.

"As a result many smokers remain unaware of the very basic fact that smoking is hazardous to health and many more hold false beliefs about the existence, probability and severtiy of these dangers," the report concluded.

To overcome the problems cited in the report, the commission's staff, noting that less than 3 percent of those exposed to cigarette advertising read printed warnings, urged adoption of new advertisement warnings.

Specifically, the commission repeated earlier recommendations that the suggested warnings list specific diseases the FTC said had been linked to smoking. Calling the current warnings "worn out," the agency recommended regular rotations of the proposed warnings on cigarette ads so that specific diseases linked to smoking would be listed in large lettering.

A spokesman for The Tobacco Institute, the industry group which has historically challenged the government's anti-smoking research and publicity activities, was highly critical of the report.

The group's preliminary reading of the report "shows us that they reveal their basic objection to advertising in general and their complete misunderstanding" of cigarette brand advertising, a spokesman said. The authors of the report "have made it clear that it is their desire to substitute their will for individual [consumers'] decisions."

The group said it will file detailed comments about the study during a six-month comment period proposed by the FTC. At the close of that proceeding, the commission will determine whether it formally wants to seek additional action.

The report comes at a time when it is unlikely that the government will expand its limited anitsmoking program. The Reagan administration has proposed consolidating several government health programs, including the antismoking program, without substantial growth in the effort's budget.

For the current fiscal year, the Department of Health and Human Services' Office of Smoking ad Health, the primary public relations arm of the antismoking activity, has a budget of just over $2 milliion. The new office, as proposed in the Reagan budget, would be allocated $2.8 million. Sources say it is unlikely any substantial funding could be added to the program.

Nevertheless, two key Republican Senate chairman essentially endorsed the conclusions of the study and suggested that the government might do more. "We need a comprehensive campaign to educate Americans on smoking and what it can do to them," said Sen. Orrin Hatch (R-Utah), chairman of the Labor and Human Resources Committee. "Ignornance of the effects of smoking is one of the greatest contributions to death and chronic diseases in the United States."

Noting that information about smoking hazards "just isn't getting through," Sen. Robert Packwood (R-Ore.), chairman of the Commerce Committee, said he is encouraged by the FTC's efforts to look into new warnings.

"Although it's too early to say which approach is most effective or fair, it's clear that consumers want and need to be educated about smoking hazards," Packwood said. "My chief concern is for the unknowing and uninformed, especially young mothers-to-be, as well as teen-agers who might find smoking attractive.

"Firm action will be needed to educate people that they are taking real risks with their lives and possibly their children's lives, whenever they light up," Packwood said.