The purpose of the paper is to review the recent empirical literature relating to the quantification and valuation of the human health impacts of air pollution, hazardous chemicals, and unsafe water and
sanitation, and their use in cost-benefit analysis, as an input to environmental policy decision-making. For each of these three environmental hazards, the nature and range of these health impacts are identified. The extent to which these impacts can, and have been, quantified and valued in monetary terms, is described.