CANNABIS JOINTS DAMAGE LUNGS MORE THAN TOBACCO - STUDY

A single cannabis joint may cause as much damage to the lungs as five
chain-smoked cigarettes, research has found. Medical examinations of
cannabis and cigarette smokers found the drug increased specific lung
problems, including obstructed airways and hyperinflation, a condition
where too much air remains in the lungs when a person exhales. Smoking
one cannabis joint caused damage equivalent to smoking 2.5 to five
cigarettes in rapid succession, researchers at the Medical Research
Institute of New Zealand found. Doctors who carried out the study
believe the damage is linked to the difference in the way cannabis is
usually smoked, with users inhaling hard, holding their breath for
longer and failing to use filters.

The report follows a flurry of confessions from ministers who admitted
having used the illegal drug and comes days after a review of cannabis
research, published in the Lancet medical journal, revealed that
cannabis use may be to blame for 800 cases of serious psychosis in
Britain.

The scientists set out to investigate whether smoking cannabis put
users at greater risk of developing emphysema, a progressive and
potentially fatal lung disease.

A group of 339 volunteers aged 18 to 70 were divided into four groups
according to whether they smoked only cannabis, only tobacco, both, or
were non-smokers. Each volunteer was then subjected to lung function
tests and x-ray scans of their chests to assess the level of damage to
their lungs and airways.

In the study, published in the journal Thorax, all smokers complained
of coughs and wheezing, while only tobacco smokers showed signs of
emphysema. Coughing was reduced among people who smoked cannabis and
tobacco, possibly because these people smoked pure cannabis joints and
so less tobacco leaf.

The extent of lung damage was directly related to the number of joints
smoked. "The most important finding was that one joint of cannabis was
similar to 2.5 to five tobacco cigarettes in terms of causing airflow
obstruction," the authors write. "This pattern is likely to relate to
the different characteristics of the cannabis joint and the way in
which it is smoked. Cannabis is usually smoked without a filter and to
a shorter butt length, and the smoke is a higher temperature," they
add.