This study is about the effects of air-pollution on health, notably covid-19. The covid-19 pandemic continues to wreak havoc in many areas of the world. The infection spreads through person-to-person contact. Transmission and prognosis, once infected, are potentially influenced by many factors, including air-pollution. Studies have suggested that air-pollution increases the incidence and the severity of the disease. However, the current data are too limited to be certain. Especially the quantitative contribution of air-pollution to the disease is still very uncertain. This document was provided by the Policy Department for Economic, Scientific and Quality of Life Policies at the request of the committee on the Environment, Public Health and Food Safety (ENVI).