LONG-TERM CANNABIS USE RAISES RISK OF LUNG CANCER

Cannabis increases the risk of lung cancer and may cause 5 per cent of
cases of the disease in people aged 55 and under, according to a new
study being published later this year.

Researchers have found a five-fold increased risk of lung cancer in
heavy users of cannabis. They calculate that the risk of developing
lung cancer increased by 8 per cent a year for people whose cumulative
exposure equated to smoking one joint a day. "Long-term cannabis use
increases the risk of lung cancer in young adults, particularly in
those who start smoking cannabis at a young age," according to
researchers from the Medical Research Institute of New Zealand.

The increased risk is blamed on the tendency of cannabis smokers to
inhale deeper and longer than with an ordinary cigarette.

The World Health Organisation in 1997 concluded that cannabis when
smoked is twice as carcinogenic than tobacco. Some doctors claim it
causes cancers of the lungs, larynx, mouth and oesophagus as well as
other chronic lung diseases. Those smoking on a regular basis are
thought to be most at risk.

The research adds to the existing evidence that cannabis use can
increase the risk of emphysema, chronic bronchitis and lung cancer.
This news comes as the debate over the dangers of cannabis - started
by this newspaper two weeks ago - continues.