SECTION 1. Section 7 of chapter 21E of the general laws is hereby amended by striking in lines 8 and 9 the words "immediately notify the department thereof" and inserting in place thereof the following: 

immediately notify the department thereof, and in the case of any such person who is a lessor, immediately notify all residential and commercial tenants of the premises thereof affected or likely to be affected.  The lessor shall make such disclosure to each existing tenant affected or likely to be affected in writing by certified mail.  The lessor shall make such disclosure in writing to each prospective tenant  affected or likely to be affected before entering into a lease or rental agreement with the tenant.  Failure to disclose this information shall constitute an unfair or deceptive act or practice under the provisions of paragraph (a) of section two of chapter ninety-three A.  This subsection shall not apply to persons leasing a slip in a marina.