does marijuanan effect the lungs.......?

Numerous studies have shown marijuana smoke to contain carcinogens and to be an irritant to the lungs. In fact, marijuana smoke contains 50–70 percent more carcinogenic hydrocarbons than does tobacco smoke. Marijuana users usually inhal more deeply and hold their breath longer than tobacco sokers do, which further increase the lungs’ exposure to carcinogenic smoke. Marijuana smokers show dysregulated growth Of epithelial cells in their lung tissue, which could lead to cancer. however, a recent case-controlled study found no positive associations between marijuana use and lung, upper respiratory, or upper digestive tract cancers Thus, the link between marijuana smoking and these cancers remains unsubstantiated at this time.