2nd Hand Marijuana Smoke where Pot/Weed is Legal

[Cheryl Crockett]

This question was inspired by the discussion entitled "Caught Tenant Smoking Weed" started by @Faisal Farnas. 

As marijuana becomes legal in more U.S. states, many landlords and homeowners will find themselves facing this scenario.
What would you do? A neighbor who now can legally smoke pot, in my city/state, is smoking inside their house (or unit) or outside on the front or back porch. The smoke drifts onto the porch or balcony and into the unit or property next door, disturbing a neighbor who doesn't smoke. On the other side, a neighbor has a medical condition that requires them to use an oxygen tank. These tenants complain to you because they can't call the police, and when  they protest to the smoking neighbors, it brings only silence and angry looks.

One neighbor is adamant about exercising their legal right to smoke weed in and around their home, while the other neighbors want to breathe clean air in theirs.

I'll appreciate your responses and advice because this is based on a true story.