Schedule B of the Workers Compensation Act (“Act”) provided a presumption of work causation in favour of a worker who had developed primary site lung cancer where there had been exposure to airborne asbestos dust and where one or both of the following diseases were present:

• asbestosis, or
• bilateral diffuse pleural thickening or fibrosis, over 5 mm thick and extending over more than a quarter of the chest wall.

At issue was whether these descriptions contained in Schedule B of the Act were current and supportable based on the most current medical science.

Consultation closed February 5, 2010.