Towards environmental health equity in health impact assessment: innovations and opportunities.

OBJECTIVES: As global environmental change drives inequitable health outcomes, novel health equity assessment methodologies are increasingly required. We review literatures on equity-focused HIA to clarify how equity is informing HIA practice, and to surface innovations for assessing health equity in relation to a range of exposures across geographic and temporal scales.
METHODS: A narrative review of the health equity and HIA literatures analysed English articles published between 2003 and 2017 across PubMed, PubMed Central, Biomed Central and Ovid Medline. Title and abstract reviews of 849 search results yielded 89 articles receiving full text review.
RESULTS: Considerations of equity in HIA increased over the last 5 years, but equity continues to be conflated with health disparities rather than their root causes (i.e. inequities). Lessons from six literatures to inform future HIA practice are described: HIA for healthy cities, climate change vulnerability assessment, cumulative health risk assessment, intersectionality-based policy analysis, corporate health impact assessment and global health impact assessment.
CONCLUSIONS: Academic reporting on incorporating equity in HIA practice has been limited. Nonetheless, significant methodological advancements are being made to examine the health equity implications of multiple environmental exposures.