I really think the odor was from the previous occupant's animals (as it was problematic with the lower cabinets and not really the uppers)- and because we didn't have animals I was more sensitive to the smell. 

When a pet pees on the carpet, it's essentially toast due to the odor. 

@Theodore Welpott, they gotta be legit!  

In 1908"At the time, Theodore Roosevelt was president, New Mexico, Arizona, Alaska and Hawaii were not yet states, and the first Ford Model T car was two weeks old."

If they were smoking outside, the odor would quickly dissipate and would not permeate the building envelope and infuse into the other units. 

Originally posted by @Theodore B.

@Theodore Xenos - Do you already own the lots?

Abating the odor (tobacco and Marijuana) is costly and time consuming. 

The odors are not always easy to eliminate within the normal apartment turnover routine.

The ozone (O3) reverts back to oxygen (O2) as it oxidizes with odors, so no toxic byproducts or odors are left behind, as long as the odor sources have been cleaned/removed...... and That's my deodorizing rant despite the fact that I don't even have a sense of smell...seriously.