Ottawa, Canada, November 30, 2007 – MDS Nordion, a leading provider of medical isotopes and radiopharmaceuticals, has provided an update to their medical isotope customers about a temporary supply issue.  MDS Nordion has received information from their primary supplier regarding an interruption in the supply of molybdenum-99 used in the manufacturing of technetium-99m generators and iodine-131. The primary supplier has advised MDS Nordion that a scheduled reactor maintenance shutdown has been extended to complete an upgrade to the electrical system, addressing a technical regulatory issue.  
 
MDS Nordion’s primary supplier is working closely with their regulator, the Canadian Nuclear Safety Commission, to finalize and complete implementation of their upgrade plan. At the same time, MDS Nordion is working closely with their global supply network to mitigate the impact of this temporary supply issue on their customers. Based on our current information, an approval of the upgrade plan is anticipated shortly with a targeted return to full production in mid-December.  The impact of this interruption is currently expected to reduce EBITDA by up to approximately US $4 million in the first quarter of 2008. 
 
About MDS Nordion
MDS Nordion (www.mdsnordion.com) is a world leader in medical isotopes, radiation and related technologies. It is a business unit of MDS Inc.(TSX:MDS)(NYSE:MDZ). MDS Inc. is a global life sciences company that provides market-leading products and services for the development of drugs and diagnosis and treatment of disease. We are a leading global provider of pharmaceutical contract research, medical isotopes for molecular imaging, radiotherapeutics, and analytical instruments. MDS Inc. has more than 6,200 highly skilled people in 28 countries. Find out more at www.mdsinc.com or
by calling 1-888-MDS-7222, 24 hours a day. 
 
Forward-Looking Statement
This document contains forward-looking statements. Some forward-looking statements may be identified by words like "expects", "anticipates", "plans”, “intends", "indicates", “targeted” or similar expressions. The statements are not a guarantee of future impact or performance and are inherently subject to risks and uncertainties. The actual impact to the Company of the  maintenance shutdown could differ materially from that currently anticipated due to a number of factors, including, the actual timing of a return to full production and other risk factors identified in other documents filed by the Company with Canadian and US securities regulatory authorities from time to time. 
 
For more information contact: 

Media: 
Shelley Maclean 
Manager External Communications
MDS Nordion 
(613) 592-3400 ext. 2414    
shelley.maclean@mdsinc.com 
   
Investors: 
Sharon Mathers  
Senior Vice-President, Investor Relations and External Communications 
MDS Inc. 
(416) 675-6777 x 34721 
sharon.mathers@mdsinc.com