Roberts Rugh, 75, a biologist and radiologist at the National Institutes of Health and a former professor at Columbia University in New York, died at Suburban Hospital in Bethesda on Friday following a heart attack.

Dr. Pugh joined NIH in 1971, the year he retired from the faculty of the College of Physicians and Surgeons at Columbia. He had taught there and done research on radiology and the effects of radiation on embryos since 1947. He was with the bureau of radiological health at NIH until his death.

He was born in Springfield, Ohio, and grew up in China, where his parents were missionaries. He earned bachelor's and master's degrees at Oberlin College in Ohio and a doctorate at Columbia. He taught at New York University before returning to Columbia as a teacher.

Among his many publications was "From Conception to Birth: the Drama of Life's Beginnings," a book for the general reader.

Survivors include his wife, Harriette Sheldon Rugh, of the home in Rockville: a daughter, Elizabeth R. Downs, of Baltimore: a son, William A. the public affairs officer at the U.S. Embassy in Cairo, Egypt, and six grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Oberlin College Scholarship Fund, Oberlin, Ohio, or to the College Light Opera Company, Falmouth, Mass.