They are important for lung function, since their purpose is the exchange of oxygen and carbon dioxide. When the airways are blocked by a mucous plug, foreign object, or tumor, the alveoli are unable to fill with air and collapse of lung tissue can occur in the affected area.
Testing Positive for Marijuana Does Not Indicate Impairment Someone can test positive for marijuana days or even weeks after they last used it. by Dr. Carl Hart @drcarlhart. AAs Oregonians consider their vote on tax and regulation of marijuana, it is important for them to have access to sound information grounded in science.
How long is THC detectable in urine? If you are a chronic marijuana user, THC can be detected in your system using a urine test for up to 12 weeks depending on the quantity as well as frequency of use. Note that if you just used marijuana once and stopped, the odds of passing a test within the first week are decent but you can still test positive for up to 30 days.