Laetrile was labeled a "hazardous" drug yesterday by U.S. Surgeon General Julius Richmond on the basis of what he called "a growing number of reports" of serious poisoning and even death caused by it.

Richmond, who is also assistant secretary for health in the Department of Health, Education and Welfare, called a news conference to disclose what he called "disturbing new information" about the controversial drug.

In the strongest indictment of Laetrile yet made by a federal health official, Richmond cited mounting reports of its toxic effects and an increasing number of reports from physicians of "patients with early, treatable cancer who have turned to Laetrile and found out too late that it doesn't work."

Dr. Arthur Upton, new director of the National Cancer Institute, said another problem is that Laetrile is being inaccurately labeled a vitamin - B-17 - and is being pushed by some promoters as a supposed cancer preventive that people might take as a daily pill.

Any regular use, especially oral use, of Laetrile or amygdalin, as it is also known, can result in cyanide poisoning, the doctors said. Laetrile is made from fruit pits, usually apricot pits, which contain cyanide.

Enzymes in the human digestive tract can break down the drug to release this deadly chemical, Richmond warned.

He also said recent tests by the Food and Drug Administration and other laboratories have revealed "serious" adulteration, decomposition, impurities and inconsistencies in the material being sold as Laetrile so that "cancer" patients who buy it are not even getting what they are paying for."

"We are now receiving early reports of serious microbial contamination" of some Laetrile by bacteria that can cause fatal blood poisoning, he added.

Richmond said he was "seriously disturbed" by the findings, especially since Laetrile is given to seriously ill cancer patients whose symptoms - or death - may be caused by Laetrile.

"I believe the information we are now starting to see may be just the tip of the iceberg," Richmond said.

Dr. Joseph Ross of the University of California at Los Angeles studied use of Laetrile and related compounds (made from other cyanide-containing fruit pits). Most of the cases were in the United States, Mexico, and Germany. He found 19 poisonings and four deaths caused by Laetrile and other apricot-kernel compounds, and 18 poisonings and 13 deaths caused by bitter almond or other fruit-kernel concentrates. "These cases have occurred sporadically" since the materials are usually forbidden, but "should they [the materials] be made generally available, cases may be expected to increase," he warned.

Dr. Jerry P. Lewis of the University of California Medical Center at Sacramento counted 17 Laetrile poisonings leading to hospitalization, with four deaths.

Georgetown University doctors last month reported serious illness caused by Laetrile in two cancer patients.

An 11-month-old Attica, N.Y., girl died after eating five of her father's Laetrile tablets. A Los Angeles girl, 15, died after swallowing a Laetrile dose she was told to inject.

The American Medical Association said Monday that "those who insist on using Laetrile as a treatment for cancer are advised to keep the tables in childproof containers and to have a cyanide resuscitation kit quickly available."

Richmond pointed out that recognized anti-cancer drugs also are toxic, many of them more so than Laetrile, but he added that "there is good reason" to believe they may help defeat cancer.

Twelve states legislatures legalized Laetrile's use, the latest of them New Hampshire on June 28. A California State Assembly health committee voted Monday against legalization.