hydrocarbons: oils, fats, alcohols, waxes, tars, can be roughly estimated from fat content

sugar burns slowly
hydrocarbons are what makes cigarettes tar like
sunlight destroys nicotine

Heating is form of oxidization. Some hydrocarbons turn into carcinogens when heated with oxygen. Ingesting carcinogens can cause cancer. 
Drinking black tea instead of green tea means you are consuming more potential hydrocarbons (and therefore less potential cancerous carcinogens), as black tea is oxidised.

In contrast; smoking tobacco which has been oxidized as opposed to tobacco which has not been oxidized, may mean you consume less hydrocarbons in the smoke,
as less hydrocarbons are actually ingested (obviously it is best not to smoke at all). Biodegradation is another form of oxidization, but some hydrocarbons do not
biodegrade. In the case of tobacco, both biodegradation and subsequent heating in the presence of oxygen may reduce carcinogens.

Burnt, or heavily cooked/heated fish, cheese, cooking oils, and fat rinds may create carcinogens that are ingested, furthermore leaving these foods in the presence of
oxygen or sunlight over long periods of time may create carcinogens.

As a precaution, always attempt to ferment foods anerobically, for instance; vinegar, yoghurt, beer etc. always attempt to cook foods anerobically.