Need advice. Not sure if baby should see my dad

Hi everyone. I really need some help figuring out what to do. My daughter is 6 weeks and my dad has only seen her once when she was 3 weeks. He's always calling me wanting Neto bring his granddaughter over to visit him. He is disabled and can't drive. But he smokes cigars and marijuana in his house and it always stinks! I don't want my baby breathing that in! I know cigarette smoke in clothing and in the house is bad, are cigars and weed smells just as bad? Worse? He has never smoked while I was there and wouldn't smoke while we were there, but I'm concerned about what's in the air and on the furniture etc. I feel so bad for keeping her from him, but I don't know what to do. He lives a half hour away minimum so I can't really drive to pick him up and bring him to my house then bring him back home with a baby. I don't want to Offend him and I'm not sure he'd understand if I told him why.