Two medical researchers say women who take jobs outside the home run a greater risk of getting cancer than those women who are homemakers. The doctors' study cites two national trends in the last decade that have influenced women's health: an increase in the number of women working, and a growing number of women smokers who work. The doctors say that while many working women hold "traditionally female" jobs such as secretary, sales clerk or waitress, ". . . tens of thousands of women are employed in high-risk industries involving exposure to numerous dusts, chemicals, radiation and other toxicants." Their study says beauticians and cosmetilogists who use hair sprays are exposed to vinyl chloride monomer (VCM), a proven human carcinogen that can cause liver damage and lung cancer. Many women also are occupationally exposed to medical and dental X-rays. They also say teachers in older school buildings and textile workers often are exposed to asbestos. According to the study, working women most likely to smoke are waitresses and factory workers, as well as those in managerial, sales and executive positions. "Many women smoke to relieve external stress. These women have a harder time quitting than men do," Dr. Steven D. Stellman told the Boston Herald American in a telephone interview from his New York office. "We all know smoking is bad," he said. "We know the risks are there for occupational hazards. When a physician combines a patient's smoking habits and exposure to chemicals and other possible occupational hazards, it contributes to better diagnosis and health care." The study was published in the current issue of Ca, an American Cancer Society journal for clinicians. The researchers were Dr. Stellman, an epidemiologist, and Dr. Jeanne Stellman, associate professor of Public Health at Columbia University.