A Holistic Approach to Chemical Mixtures in the Canadian Environment

C anada is piloting a new, integrated, regional approach to understanding and managing real-world environmental chemical mixtures under the Canadian Environmental Protection Act, 1999 (CEPA), recently modernized through the Strengthening Environmental Protection for a Healthier Canada Act in 2023.The Integrated Chemical Mixtures Project (ICMP) encompasses activities in two regions in the south of the Province of Ontario, the City of Brantford/ Grand River (mixed inputs, e.g., urban and agricultural land uses) and the City of Sarnia/St.Clair River (heavily industrialized), to generate data on mixture compositions, exposure pathways, and cumulative effects, in direct collaboration with regulatory scientists, all levels of government, environmental organizations, and Indigenous partners (Figure 1).This project provides the conceptual and methodological foundation for future national activities under CEPA.