its not necessarily a bad thing but its not a good habit to have. plants breath through stomata which are like tiny little mouths on the underside of the leaf. these stomata take the co2 rich air in that the plant turns in into the o2 that we breath. the smoke will stiffle this process
the only thing you want your plants breathing is co2
if u want to make a difference, maybe reading a book or working out around your plants will help them ahahah extra co2