mj smoke scars the lungs, making you more susceptible to lung infections and even cancer(marijuana smoke has been found to contain more
cancer-causing agents than is found in tobacco smoke), bronchitis, pleaurisy, pneumonia, and can even cause asthma...but compared to other things in the air that can cause the same things, I wouldnt worry about it(unless done excessivley over time, then I would worry ....and please, save the smart ass comments about what Ive posted for something you know, my father is a doctor that specializes in pulmonary and respiratory problems, and I've been very open with him on my use of everything, and he has offered medical advice on everything Ive asked including this!!