Out of curiosity, have you tried calling your local public health department to find out what the laws involve when you've got shared ventilation? Have you tried calling the housing board for your state, to find out similar? I'm not entirely sure about the legality of this entire setup, and if that's the case, your landlord is required to solve the problem. You don't have to necessarily report anything until you know what's cool and what's not, but just call around on a fact-finding mission.