By James Gerstenzang, Times Staff Writer

WASHINGTON — In some of its most comprehensive work in three years on the dangers of tobacco, the federal government said today that smoking is increasingly a habit of the poorest Americans, and that tobacco use harms nearly every human organ.

Forty years after the publication of the groundbreaking surgeon general’s study that alerted Americans to the cancer risk of cigarettes, the current surgeon general, Richard H. Carmona, issued a new report that found additional dangers and said that cigarettes producing lower tar and nicotine than conventional cigarettes provide no clear health benefits.

Taken together, the surgeon general’s report and the document produced by the Centers for Disease Control portray a nation making small gains in its fight against tobacco; for the first time, more people who say they have smoked count themselves as former smokers than as current smokers.

The CDC report found that there are fewer smokers per capita among those living above the poverty line, and those who are better educated, and that the wealthier and better educated are quitting at a faster rate than the others.

The surgeon general’s report found that as scientific knowledge has expanded, the risks of smoking have grown more apparent: The dangers, Carmona said, go far beyond the well-documented risks to circulatory and respiratory health and include risks to reproduction, kidneys and sight. His report also found that the number of specific types of cancers fueled by smoking is wider than previous reports had stated.

The surgeon general added to the list of illnesses and conditions linked to smoking the following: cataracts, pneumonia, acute myeloid leukemia, abdominal aortic aneurysms, periodontitis, which is inflammation of the periodontal tissue, and cancers of the stomach, pancreas, cervix and kidneys.

“We’ve known for decades that smoking is bad for your health, but this report shows that it’s even worse,” Carmona said in a statement. “The toxins from cigarette smoke go everywhere the blood flows.

“There is no safe cigarette, whether it is called ‘light,’ ‘ultra-light,’ or any other name,” he said.

Among the major tobacco companies, Brendan McCormick, a spokesman for Phillip Morris USA, said, “We agree with the medical and scientific conclusions that cigarette smoking causes serious diseases in smokers, and that there is no such thing as a safe cigarette.”

Seth Moskowitz, a spokesman for R.J. Reynolds, said of the surgeon general’s report: “We have no comment on it. We’re just not commenting on it.”