History for Chron

U.S. Surgeon General Julius Richmond said in his annual report on smoking that cigarettes with less tar reduce the risk of lung cancer but not several other forms of disease related to the habit.

Richmond warned that additives used to enhance the flavor of low-tar cigarettes may cause cancer, but scientists can’t definitively say because cigarette makers are not required to disclose what is in the additives.

Cigarettes with less tar and nicotine were shown to cause less lung cancer. They haven’t, however, been shown to reduce tumors, heart, lung and prenatal diseases, Richmond said.

“Some additives available for use are either known or suspect carcinogens or give rise to carcinogenic substances when burned,” he said. “The use of these additives may negate beneficial effects of the reduced tar yield, or might pose increased or new and different disease risks.”

Richmond said the smoking segment of the population has dropped from 40% in 1964 to 32.5%.

William Toohey Jr., of the industry-trade group call The Tobacco Institute, called Richmond’s report “markedly candid in pointing out the lack of knowledge and needs for scientific research on major diseases which have been statistically associated with smoking.”