There are limitations to conventional occupational health and safety research approaches and practices and numerous barriers to overcome in order to achieve progress. Occupational health and safety is impacted by the broader social-political environment. Corporatism affects the directions, ideas and practice of regulators, educators, the labour movement, scientists, medical professionals, and society as a whole, thus inhibiting workers' power to influence change. The thesis therefore explores both the wider influences and barriers to occupational health and safety advances, focusing particularly on the Canadian situation, through the general research questions: What has influenced occupational health and safety policies and practices, especially in Canada? What are some of the limitations of conventional occupational health and safety research and practices? To what extent can participatory action research and mapping address identified limitations? These questions are explored from the perspective of the population potentially at risk. New theories and approaches to occupational health and safety research are then applied in this thesis in order to explore a more specific multi-part research question: Can mapping within worker-based participatory action research be used to explore occupational health and safety conditions? In particular, can mapping contribute to occupational health and safety improvements at a local level and beyond; establish workers' previous exposures for compensation purposes; support efforts to bring about justice through compensation for workers affected by unsafe working conditions; and raise worker and public awareness of health and safety? These questions are explored through two different case studies, which examine, in depth, occupational health and safety action and possible remedies. Casino gaming workers in Windsor, Ontario, Canada undertook a collaborative study to investigate and improve current health and safety conditions. Former Holmes foundry and asbestos insulation workers in Sarnia, Ontario, Canada undertook a collaborative study to provide evidence of exposures and ensuing health problems to support claims for compensation. The outcomes of the case studies shed light on the bigger Canadian health and safety picture and demonstrate that mapping as a data collection method used within a participatory action research approach can accomplish a broad range of objectives. Mapping can raise workers' awareness, facilitate communication, build solidarity and cohesiveness, foster community support, mobilise workers to take action to reduce hazards or win compensation, in turn influencing employers, the compensation board and government agencies. The case studies accomplished the shared objective of raising worker and public awareness. The casino workers also gained occupational health and safety improvements and the Holmes workers were successful in gaining compensation.