damage from one cigarette does affect your lungs Smoking slowly damages your lungs, often without clear symptoms at Smoking and Chronic Lung Disease:
Description
Shimkin, whose population studies at the National Cancer Institute in the 1950s would help show a link between smoking and lung cancer, is quoted in the book: Although truly useful drugs for the treatment of cancer are still in the future, there is no reason but to be optimistic that they eventually will be found Cancer research is but a small segment of the total human endeavor in biomedical sciences
A guide to initial NRT dosing is shown in Figure 4

The big one for burn rate is a class of salts known as burn accelerants, with diammonium phosphate being the most notorious: it makes the tobacco burn hotter and faster, and it keeps the cigarette lit between puffs

As you can expect, there is a lot of special interest push back

Severe, long-term smoke contamination may require professional equipment and expertise for complete and lasting restoration

S2CID 73511138