Dr. Wilhelm C. Hueper, 84, a retired official of the National Cancer Insititute who was a pioneer in the study of cancer-causing agents in the environment died of cardiac arrest Thursday at the Wisconsin Avenue Nursing Home.

From 1948, when he joined NCI, until his retirement in 1964, he was chief of the institute's environmental cancer section.

Dr. Hueper conducted research into the cancer hazards of heavy metals, petroleum derivatives, synthetic hydrogenated coal oils, asbestos, food additives and plastics.

A colleague at the NCI once characterized Dr. Hueper as possessing, "in high degree" the "ability to shock and alarm."

Examples of this included assertions that he made in the early 1960s that 71 to 80 percent of cancer cases would turn out to be environmental in origin. Although many considered him an alarmist at the time, authorities now acknowledge that 70 to 90 per cent of all cancer is related to environmental factors.

During the early 1950s, he helped spotlight the high incidence of lung cancer in workers in the chromate producing industry. He directed research that discovered that carcinogenic chromates were those most soluble in water, and thus broken down in the body. His works helped to lower the cancer rate dramatically in the industry.

Another coworker said Dr. Hueper was "controversial and misunderstood. He irritated the devil out of the bierarchy of command."

This resulted in Dr. Hueper's speaking out ahead of his time in advocating tighter laws and more thorough research into the possible carcinogenic properties of drugs.

He testified in favor of the Delaney Amendment, passed by Congress in 1958, which barred substances known to induce cancer in animals from being used in drugs consumed by humans.

Although the law itself became controversial in recent years, due to criticism concerning the validity of large doses of drugs to laboratory animals applying to small amounts of the drug to humans, Dr. Hueper continued to favor it.

He once wrote that "The data from such tests are not necessarily unrealistic. Although must agent tested are either weak careinogens or act in relatively small doses, people may ingest them over a period of many years. The cumulative effect might then parallel that of a massive dose."

In 1978, Dr. Hueper was given the National Institutes of Health Director's Award.

The award cited his research in luekemia, his pioneer work in chromium research, and also hailed his book, "Occupational Tumors and Allied Diseases," a standard text since its publication in 1942.

His other awards include the 1959 Rosenthal Award from the American Association for the Advancement of Science and a 1962 award from the World Health Organization for his studies.

In 1963 the editors of Modern Medicine voted him a distinguished achievment award for "his identification of carcinogenic substances and his undaunted courage in effecting control of noxious environmental agents in industry."

Dr. Hueper was born in Schwerin, Germany, and earned his medical degree at the University of Kiel. He began his cancer research in Europe in the early 1920s, where he published findings on the rise of lung cancer in industrial cities.

He came to this country in 1923, and practiced medicine and taught pathology in Chicago and Philadelphia before joining the duPont Company in Wilmington, Del., in 1934.

At duPont he charted a high incidence of bladder cancer among dye workers, isolating the carcinogenic substance that caused it. He left duPont to join the Warner pharmaceutical laboratories in New York in 1938, remaining there until 1948 when he came to the National Cancer Institute.

After retiring from NCI he worked in projects to obtain funds for persons stricken by cancer who had worked in professions that exposed them to a high degree of risk.

He pointed out in a 1976 interview with The Washington Post, "The whole financial burden of cancer hazards is carried by the general public or by the workers themselves."

Dr. Hueper was among the first authorities to cite a time lag of up to several decades between exposure to carcinogens and the outbreak of cancer symptoms.

His professional memberships included the American Society of Experimental Pathology, the American Association of Cancer Research, the American College of Pathology, and the American College of Preventive Medicine.

He was the first President of the American Society for the Study of Arteriosclerosis.

Survivors include a son, Klaus, of Bethesda, and one grandchild.

The family suggests that expressions of sympathy be in the form of contributions to the Washington Humane Society. CAPTION: Picture, Dr. Wilhelm C. Hueper, 1962 Photo