Cannabis smoke contains many of the same components as tobacco smoke. It is important to be aware that as much as four times the amount of tar can be deposited on the lungs of cannabis smokers as cigarette smokers if a cigarette of comparable weight is smoked. The difference in tar level is likely to be the result of differences in administration. Cannabis cigarettes usually do not have filters and cannabis smokers usually develop a larger puff volume. Smokers also inhale more deeply and hold their breath several times longer than tobacco smokers. This is done to savour the taste of cannabis and to ensure that as much THC is absorbed into the blood stream as possible. Chronic smoking effects are similar to those of tobacco smoking. Chronic heavy use of cannabis is associated with increased symptoms of chronic bronchitis such as coughing and wheezing. Lung function is impaired and there are greater abnormalities in the large airways of cannabis smokers than non-smokers. Cannabis smoking is associated with changes in bronchial tissue. Many cannabis smokers have erythema (increased redness of airway tissues) and edema (swelling of the airway tissues). Studies have shown that people who are regular users of cannabis but not tobacco have more symptoms of chronic bronchitis than non-smokers. This is not really surprising, though, is it? Even without tobacco, cannabis smoking is still smoking.
