Hi Frouke,
I'm sorry that you have to cope with tobacco and marijuana odors! That's really bad especially with lung cancer. When the smells come into your home, you might just try heating a pan of water sprinkled with cinnamon on the stove. The cinnamon smell will go all over and get rid of or mask the bad smells. I've tried this before and it really works good. Another thing I do is put Mentholatum in my nose. Mentholatum is not an antihistamine. I put it in my nose on Monday mornings when I would be out gardening in the summer and the maintenance guy in the apartments behind my mobile home would be leaf blowing with a strong gas blower. The gas fumes really bothered me but with the Mentholatum in my nose I didn't smell them.

I know it's hard to cope with all this pollution. It can be depressing. However, when you feel depressed just pray to God and ask for his help. It doesn't have to be a formal prayer. Just talk to him like he's your best friend and he is! I talk to God several times a day. Since my husband died in July I don't have anyone else to talk to. I'm going to be 79 in May and everyone I knew or was related to have all died too. The nice thing about talking to God is that he often answers my prayers.
I wish you the best. If you ever feel like talking, I'm here.
PML