Environmental health is the study of how the environment affects human health. Human health is dependent on the environment. It differs from the study of how humans affect the environment.
Environmental Health Impact Assessment (EHIA) is a study done to predict and assess the impact of proposed projects on the human health and the distribution of those effects within the population. It provides unique opportunities for the protection and promotion of human health. EHIA aims to reach objective, robust and evidence-based conclusions on the likely effects of a project
Environmental Impact Assessment (EIA) is a study done to predict and assess the impact of proposed projects on the environment. Environmental Health Impact Assessment (EHIA) is partly covered in the EIA section on health and safety. This is because EIA includes some aspects of health. For instance, EIA considers the effect of a proposed project to human health in relation to air, water quality, noise etc.