Second hand smoke...........?

im 18 in 3weeks, and i have never touch a smoke in my life!. i amm the Only 1 in the house who doesnt smoke lol other then my lil 5yr old brother. even my sister who jst turn 17 smokes. but i cant standd it what is y im mustly always in my room but when im in the livin room its like always smokey and i knw seicond hand smoke 'the smoke n the air' is BAD even badder then the person smokein so im wonderin how long would it take to ruin a life or get in ur lungs??. i have told them be4 tht i fu*kin hate the smell and everything but no1 listens and still do it