If you are facing poor living conditions in your apartment, first, you should notify your landlord. Most landlords usually will respond and at least make an effort to correct the problem(s). If your landlord has a history of not responding to your concerns, make sure you put your request in writing (and keep a copy). Since most people have email, send your request through email..
If the landlord doesn't respond and the problems are serious, you should call your local board of health. The board of health will issue a report on the conditions (sometimes it can take weeks for the inspection and a few more weeks for the report). The report is the key to you getting the conditions fixed and possibly compensation for living in the poor conditions.
The board of health will give the landlord some time to correct the problems (a few days to a few weeks). The board of health will follow up with another inspection.
Landlord fails to correct problems even after board of health is called.
If the landlord still refuses to correct the problems with the apartment, even after the board of health has been called, you should consider calling a local landlord tenant lawyer. The laws covering landlords and tenants is very technical and the lawyer should fully understand them all... If the landlord will not correct the problems, you as a tenant need to start documenting the problems. Take photos, take videos, take notes when you talk to your landlord. Keep all your records organized, this will greatly help your lawyer if you contact one. Also keep in mind most laws concerning landlords and tenants GREATLY favor the tenant. There are a lot of laws that will require the landlord to pay your legal fees if you win your case. Also, a lot of lawyers (including myself) give free consultations so you can understand your rights and responsibilities.
Finally, don't say or put anything in writing you don't want a Judge to see/hear. Be professional, even if the landlord is not.