My mom was a pack a day smoker growing up and smoked inside (those were the days) for 13 years.

Whether it is regular cigarette smoke or Marijuana if it is disturbing a tenant you ,as the landlord, have the authority to prevent the smoker from disturbing non smokers.No one has a right to disturb others and landlords have the obligation to insure that no tenant is disturbed.

This was on a 46 year old female, non-smoker, preferred.

I've had a couple of those experiences already, including stolen items from the house, vomit inside my house, people getting drunk and peeing in the front yard in clear view of neighbors/ other houses, recently an idiot thought it was a good idea to put out a cigarette on my stucco... yes, really. 

I know I have a clause in my Proper policy that covers remediation of cigarette, weed and other drug use in the property up to 25k.

I would also take a look at alcohol and cigarette company profits  during a recession, as they actually go up, not down.

A house that has a dog in it is far worse and smokers in a house are worse than even that.

It’s a duplex and the prior owners lived in the lower unit and was a smoker.

For example, you can refuse to rent to smokers or disallow pets because smokers (and pet owners) as a group are not protected by antidiscrimination laws.BestPri

I was lucky the ozone generator worked, it was only one person in the house who was a smoker and she was only in there for a year.