One difficulty in the question: the behaviour or toxicity varies hugely among compounds.
Exhaled air from a cigarette smoker contains mainly nitrogen. Plus oxygen, carbon dioxide, argon, water vapour, and so on. But you shouldn't care about these. They constitute fresh air too.
As opposed, you might care about polycyclic aromatics, nicotine and others, which are very minor constituents, but can deposit on clothes or be harmful.
Since trace compounds do matter, such an attempt would have to consider many thousand compounds, as is usual in a natural process, and finding the important ones needs knowledge, insight, perseverance and so on. A list and a threshold won't do the task.