What are the long-term effects of marijuana use?
Findings so far show that regular use of marijuana or THC may play a role in some kinds of cancer and in problems with the respiratory and immune systems. • Cancer. It’s hard to know for sure whether regular marijuana use causes cancer. But it is known that marijuana contains some of the same, and sometimes even more, of the cancer-causing chemicals found in tobacco smoke. Studies show that someone who smokes five joints per day may be taking in as many cancer-causing chemicals as someone who smokes a full pack of cigarettes every day.15 • Lungs and airways. People who smoke marijuana often develop the same kinds of breathing problems that cigarette smokers have: coughing and wheezing. They tend to have more chest colds than nonusers. They are also at greater risk of getting lung infections like pneumonia. • Immune system. Animal studies have found that THC can damage the cells and tissues in the body that help protect against disease. When the immune cells are weakened you are more li
