Kissing my newborn?!?! 🙅🏻‍♀️🙅🏻‍♀️

Okay, so I’m due to give birth in 12 days to my daughter (1st baby) how would I go about letting family members and friends know not to kiss my baby? My stepmom and her family are very “oh, nothing gonna happen” kinda people if that makes sense, and to top it off too, They smoke also, and to be completely honest I don’t want them holding her if they have been smoking, so how would I go about saying in a nice way about the kissing and smoking?