air pollution; air quality; coronavirus disease 2019/ep [Epidemiology]; coronavirus disease 2019/et [Etiology]; disability-adjusted life year; disease association; editorial; environmental factor; epidemiological data; global disease burden; human; infection rate; mental disease; morbidity; mortality; non communicable disease/ep [Epidemiology]; non communicable disease/et [Etiology]; pandemic/ep [Epidemiology]; patient counseling; PM2.5 exposure; population density; risk factor; socioeconomics; years lived with disability; years of life lost