Snakes have a sense of smell that is better than a dogs so yes they will notice it what reaction they have is anybodies guess. Cigarette and cigar smoke is just as much as a cancer risk for snakes as everything else polonium 210 is a smoke borne radioactive particle and has as much chance (1 in 5) as causing cancer in reptiles as in humans. Reptilian cancer is much slower spreading than human so I guess it isn't as big as a problem but then again there is no treatment either.