For decades, pollution and its harmful effects on people’s health, the environment, and the planet have been neglected both by Governments and the international development agenda. Yet, pollution is the largest environmental cause of disease and death in the world today, responsible for an estimated 9 million premature deaths. The Lancet Commission on pollution and health addresses the full health and economic costs of air, water, and soil pollution. Through analyses of existing and emerging data, the Commission reveals pollution’s severe and underreported contribution to the Global Burden of Disease. It uncovers the economic costs of pollution to low-income and middle-income countries. The Commission will inform key decision makers around the world about the burden that pollution places on health and economic development, and about available cost-effective pollution control solutions and strategies.