Me. Stat. tit. 14 § 6030-D

8.
Termination of lease or tenancy at will.
If a test of a residential building under this section reveals a level of radon of 4.0 picocuries per liter of air or above, then either the landlord or the tenant may terminate the lease or tenancy at will with a minimum of 30 days' notice. Except as provided in section 6033, a landlord may not retain a security deposit or a portion of a security deposit for a lease or tenancy at will terminated as a result of a radon test in accordance with this subsection.