There is robust data that the risk of first-hand smoke is not a linear relationship between cancer (and other bad stuff) and dose--no amount of smoking is safe.
To be frank you are uninformed on basic statistics as well as medicine.
You are doing the standard thing that many educated people do when they think they are smarter and more informed than they are. You dress up a bad take as if you found some secret (CDC's hypocritical language) and assume that a mathematical relationship exists ("obviously exposure to bad stuff carries linear risk"), when it is actually more complex than that (if we can call a binary relationship more complex than linear lol).