The Central Artery/Third Harbor Tunnel (CA/T) construction project in Boston is the largest and most costly highway construction project ever undertaken in the United States. The Construction Occupational Health Project (COHP) of the Work Environment Department at the University of Massachusetts-Lowell was established to conduct exposure assessment and to develop, introduce, and evaluate interventions in the areas of ergonomics and industrial hygiene on the CA/T project. For both political and practical reasons, COHP is using a participatory approach to intervention in the construction industry. The research process is employing participation at all the levels of the construction hierarchy in the form of various advisory groups. These advisory groups have been formed from existing joint labor-management advisory committees and are presently engaged in two participatory intervention activities: (1) evaluations of intervention ideas, and (2) comparisons of safety systems.