Cardio respiratory i believe. correct me if i’m wrong
The answer to your question is nail polish remover
From what i heard, when carbon monoxide is in a person's blood (smoker or non smoker) it can kill you, it is a sign of poison in your blood. With smokers it is worse because they are smoking something that has a high content of carbon monoxide which can cause heart problems, lung cancer, birth defects, etc. So thats what i think