Study finds cannabis and tobacco equally bad

 Smoking cannabis is as bad for your lungs as smoking cigarettes.
Smoking both cannabis and tobacco narrowed people’s airways even more than smoking only one of the substances. The study involved examining how much breath about 900 people aged 18 to 26 could expel forcefully from their lungs. People who smoked cannabis and tobacco expelled less air in a second than non-smokers and took longer to expel all the air from their lungs because their airways had narrowed slightly.
Airflows decreased even more when people smoked both cannabis and tobacco. Smokers breathing and airways were effected by the tar in tobacco. Cannabis had similar levels. The study group members were examined three times in eight years. While all were healthy and differences in their airflows subtle, the figures highlighted a trend , professor Taylor said.
The researchers interest was sparked by cannabis use increasing significantly in most developed countries in the past three decades and people increasingly questioning if it was worse than smoking tobacco.
Professor Taylor said the study was complex because group members lung development was at different stages. Lungs grew and became more efficient during childhood and adolescence , then efficiency started naturally declining in the mid 20s.
The study would continue when the people were aged 32-37.

Source: Professor Robin Taylor, Dunedin Multidisciplinary Health and Development
study reported in New Zealand Herald Aug 2002