EurekaAlert has the latest oh-no-it's-worse-than-we-thought:
Scientists are reporting that so-called "thirdhand smoke" — the invisible remains of cigarette smoke that deposits on carpeting, clothing, furniture and other surfaces — may be even more of a health hazard than previously believed. The study, published in ACS' journal, Environmental Science & Technology, extends the known health risks of tobacco among people who do not smoke but encounter the smoke exhaled by smokers or released by smoldering cigarette butts.
Yael Dubowski and colleagues note that thirdhand smoke is a newly recognized contributor to the health risks of tobacco and indoor air pollution. Studies show that that nicotine in thirdhand smoke can react with the ozone in indoor air and surfaces like clothing and furniture, to form other pollutants. Exposure to them can occur to babies crawling on the carpet, people napping on the sofa, or people eating food tainted by thirdhand smoke.
I like that: tying in babies. Yes, and they're crawling on the carpets of death! Well played sirs. But you neglect the biggest threat of all, which is fourth-hand smoke.
When you've heeded the Scientists' warnings, and you've quit smoking, and you've avoided secondhand smoke, and scrubbed your house clean of third hand smoke, you think you're safe. But in scrubbing that toxic house clean you have inadvertently contaminated yourself with third-hand residue, which will later expose anyone you come in contact with to fourth-hand smoke. Shake their hand = seal their fate.
And there's no way you can prove that fourth-hand smoke isn't the deadliest of them all.
But if you've accidentally exposed others to fourth-hand smoke, don't be to hard on yourself. Yes, you've probably caused a few deaths, but on the bright side, your impact was nothing compared to the damage done by the fifth-hand smoke spreaders you infected. They're probably out there right now, touching children's faces and petting baby ducks.