My question involves public health law in the State of: California

I own a home and reside in it. A house adjacent to my property is a single family dwelling, and the owner lives off site. He rented it to a young couple a month ago. Almost every day and evening this couple burns something in their fireplace so that smoke is easily seen spewing forth from their chimney. Most of the time the stench-smoke blows toward my residence. It is very annoying. No other nearby home does this.

I've taken pictures of the chimney smoke.

How best to approach this problem? Don't I have a right got breath clean air and not have my place smell of smoke? Is their a State Law governing this other than "clean air" days? Should I offer to pay for some sort of after-burner? Should I contact the home owner who resides 25 miles away? (He is not a happy person and has many health issues including cancer, thus this is not a good option)

Don't want to have upset neighbors, but I'm fed up with this.

Help!