I think there's some evidence for short-term irritation of the lungs, such as acute bronchitis, although the evidence doesn't suggest that there are serious long-term effects on pulmonary function and respiratory function. Certainly there's short-term irritation. There are the acute effects on cognition so that while people are intoxicated on cannabis, there's cognitive interference with memory and attention as well.
On May 13th, 2014. See this statement in context.