Smoking rates among doctors and nurses are going down, but in some cases these health professionals are more likely to smoke than the general population, the American Cancer Society said this month.

The society found that male nurses are the heaviest smokers among health professionals surveyed, with 41 percent of them smoking, a level called "unusually high." This compares with 25 percent of the U.S. male population at large.

On the other hand, male doctors (16.2 percent smokers) smoke much less than the general population. And female doctors (21.3) smoke about as much as the female population at large, according to the survey of almost 1.2 million men and women age 30 and up.

"In the early 1950s, more than 50 percent of physicians smoked," the society said in its journal, called Ca, which is the medical abbreviation for cancer. "By 1975, the rate had dropped to 20 percent," and in 1982, it stood at 16.7 percent, the survey found.

Among the other findings: One doctor in three is a former smoker. Female nurses smoke more than the female population at large, 23.6 percent compared with 21.5 percent. Only 16 percent of dentists smoke.

"Physicians in particular are seen as exemplars," the society said, "and publicity about the low percentage who smoke may influence some people to quit."