Can inhaling burnt fumes from black and mild tips be dangerous

[K22_1]

For about six months if bein smoking black and mild at work and when it gets really small sometimes the tip would burn and I would get about 2 or extra hits then it occured to me a lil late that I'm basically inhaling plastic I did not do this every day but I did it a lil to much witch us concerning would I be in danger of lung cancer or lung problems beacuse of this are the tips really made of plastic