The US Surgeon-General Richard Carmona, in a report published on Thursday, said smoking could lead to cataracts, acute myeloid leukemia and stomach cancers.

"We have known for decades that smoking is bad for your health, but this report shows that it's even worse," Dr Carmona said.

"The toxins from cigarette smoke go everywhere the blood flows. I am hoping this new information will help motivate people to quit smoking and convince young people not to start in the first place," he said.

The report coincides with a study from the US Centre for Disease Control and Prevention showing that in 2002, 22.5% of US adults described themselves as smokers, down slightly from 2001.

Costly killer

Smoking kills an estimated 440,000 Americans a year, Carmona said. He said men who smoke cut their lives short by 13.2 years on average and female smokers lose 14.5 years.

"We have known for decades that smoking is bad for your health, but this report shows that it's even worse"

Richard Carmona
US Surgeon General

Smoking costs the country $157 billion each year - $75 billion in direct medical costs and the rest in lost productivity.

The poor and less educated continue to be the biggest smokers, and more efforts need to be directed at these groups to encourage them to quit smoking," Dr Carmona said.

He said efforts need to be stepped up to help people kick the habit, including quitlines and assistance programmes.

Some groups said the government needed to get much tougher on the tobacco industry.

States should raise tobacco taxes and ban all smoking in public places," American Heart Association chief executive officer M Cass Wheeler said.