Cigarette Odor Coming from Heater Vents?

I live in an apartment in a non-smoking building, but my upstairs neighbors were smoking like chimneys. The landlord told them they had to stop and only smoke outside. Though they are no longer smoking indoors, the cigarette smell is still coming out of my heating vents. Is there any way to get rid of this? I hate the smell and it wreaks havoc on my sinuses.

By Maggie