Health Impact Assessment is a systematic process that uses an array of data sources and analytic methods and considers input from stakeholders to determine the potential effects of a proposed policy, plan, program, or project on the health of a population and the distribution of the effects within the population. HIA provides recommendations on monitoring and managing those effects. National Research Council of the National Academies, 2011
Two basic terms critical for health impact assessment are health and equity.
Health is a state of complete physical, mental, and social well-being and note merely the absence of disease or infirmity.
Equity – The just and fair inclusion into a society in which everyone can participate and prosper.  The goals of equity must be to create conditions that allow all to reach their full potential.
Health status is determined by Genetics (20-30%), Health care (10%), Social conditions and behavior (60-70%). Journal of Health Affairs 2002.
Purpose of HIA – the purpose of the HIA can judge health effects of a proposed project, plan or policy highlight health disparities, provide recommendations, raise awareness among decision makers and the public, make health impacts more explicit.
Benefits of HIA –  the HIA process engages & empowers community members, recognizes lived experiences, builds relationships & collaborations, improves the evidence, improves transparency in decision making.