The son of a Bell Laboratories electrical engineer and a homemaker, Wilmot Coles Ball Jr. was born and raised in Paterson, N.J., and graduated in 1945 from Ridgewood High School.
After earning a bachelor's degree in 1949 in electrical engineering from the Johns Hopkins University, he enrolled in the Cornell University School of Medicine, from which he earned a medical degree in 1954.
Dr. Ball received postgraduate training at Johns Hopkins Hospital, the National Institutes of Health and the Royal Victoria Hospital in Montreal.
An internationally known expert in the study and treatment of lung disease, Dr. Ball was working at the Royal Victoria Hospital when the chairman of the department of medicine at Hopkins Hospital recruited him in 1961 to come to Baltimore and serve as the first director of the newly established division of respiratory diseases, now pulmonary and critical care medicine.
He headed the division until 1973. He remained a member of the medical school faculty at Hopkins, where he was a professor of biomedical engineering and environmental health sciences, after being named director in 1975 of pulmonary medicine at Good Samaritan Hospital.
In 1983, he was elected president of the hospital's medical staff and remained on its board from 1986 to this year.
Dr. Ball was later director of clinical record systems at Hopkins Hospital. During the 1970s, he headed a National Cancer Institute research team that was established in 1974.
"The project still continues to this day," said his son, Dr. Douglas W. Ball, an endocrinologist who lives in Baltimore.
Dr. Ball's research committee concluded that cigarettes were the cause of 90 percent of lung cancer cases and accounted for 80 percent of cases of emphysema.
"If people are looking for health insurance, they should stop smoking, that is much cheaper and a more effective way of reducing the likelihood of getting lung cancer," Dr. Ball told The Evening Sun in a 1978 article.
Dr. Ball said at the time that lung cancer was the No. 2 killer of women, and that the incidence and mortality of lung cancer among women would rise dramatically during the next two decades.
"It's not that women are less susceptible," Dr. Ball told the newspaper, "they just have not had the exposure. In the past, they smoked less and they did not inhale as deeply."
Dr. Ball was a proponent of X-rays for heavy smokers.
"If I'm giving advice to patients, I tell them that if they cannot give up smoking, they should seriously consider having annual chest X-rays and sputum cytology [a cancer test based on phlegm] even though the benefits are unproved," Dr. Ball told the Associated Press in a 1980 interview.
Andrew Mirabole, former executive director of the American Lung Association, was a longtime friend of Dr. Ball's. "He had been on my board," said Mr. Mirabole, who stepped down as director in 1987.
"He was a very kind, generous and down-to-earth person," said Mr. Mirabole. "He gave a lot of his time to our professional education seminars for physicians. He was always willing to do that."
Dr. Ball was the author of more than 60 scientific publications, including pioneering work in lung physiology, inflammatory lung diseases and lung cancer screening.
Dr. Ball was an accomplished woodworker and enjoyed working in the wood shop at the Towson retirement community.
Dr. Ball's wife of 44 years, the former Helene Metzler, a registered nurse, died in 1996. His second wife, of a decade, the former Nancy Winton, a psychiatric nurse, died in 2012.
A memorial service will be held at 3 p.m. Oct. 26 at the Towson Unitarian Universalist Church, 1710 Dulaney Valley Road, Lutherville.
In addition to his son, Dr. Ball is survived by a daughter, Alison C. Ball of Cambridge, Mass.; a stepson, Charles Lyon of Pittsburgh; a stepdaughter, Michelle Manthey of Lafayette, Colo.; and four grandchildren.