Air quality in Spain temporarily improved during the first wave of COVID-19, largely as a result of mobility restrictions. Until recently, however, the effect of this improvement on the health of the population was poorly understood. A new study led by the Barcelona Institute for Global Health (ISGlobal), a center supported by the "la Caixa" Foundation, together with the Barcelona Supercomputing Center (BSC-CNS), has estimated that this improvement in air quality prevented around 150 premature deaths in Spain's provincial capital cities.