Environmental hazards can pose significant health problems for renters and should be dealt with immediately.  The landlord is legally liable for ensuring that the rental unit is in a safe and liveable condition as expressed in city or county housing codes. However, it is also up to the renter to maintain a sanitary living condition as well.  While most disputes are resolved through mediation or arbitration rather than a trial, it is important to have a real estate lawyer represent you in court during an environment hazard dispute to ensure that you are not unfairly held liable for the environmental hazard, and to also to ensure that the landlord will deal with the matter and if necessary, pay damages to you.