Environmental assessment (EA) is required in Canadian federal and provincial jurisdictions as part of the process for decision-making on the acceptability of development projects. With increasing recognition of the relationship between environment and health, assessing "health" impact has growing importance. This paper presents the framework that is being developed by the World Health Organization (WHO) for addressing environmental health indicators, reports on the findings of a series of five regional workshops held in 1995-96 to examine the role of health professionals in environmental assessment in Canada, and presents a case study illustrating how human health has been addressed in a prominent EA conduct in northern Saskatchewan. Opportunities for future development of environmental health indicators are considered, with special reference to the potential use of medical data to address these challenges.