A more common problem is the horrible smell on people who smoke. Since I have asthma I avoid anyone I see smoking, but can't always predict who will have the tobacco odor in their clothes and hair until I get close enough to be effected.
People who smoke have no idea they always smell like dirty ashtrays because their noses are used to the odor. Usually their homes stink, too since the odor is absorbed into the curtains, upholstery, and even walls. Some of that happens even if they smoke outdoors because it's carried in on their clothes. And it's not polite to admit that I must refuse an invitation to visit someone because their home stinks, so instead I make up excuses.
Interestingly, some of those people have Asthma, Emphysema, lung cancer or COPD themselves, but they keep lighting up. That concerns me because one of my family members died of emphysema after years of smoking and it wasn't a pleasant experience.
According to the CDC, over 20% of adults in the USA are smokers and people I know who are in recovery from other addictions say tobacco is by far the hardest addiction to recover from. Maybe if the rest of us told everyone who smokes that they stink at least fewer people would be tempted to start the habit.