Saleem Ibrahim, Researcher at the CTU in Prague, presented high resolution (1 km), full coverage of inhalable particulate matter (PM2.5) maps of whole Europe for the years 2018–2020 using open-source data. This was a major finding of his study, which aims at gaining a better understanding of these small particles, one of the most harmful air pollutants to all living things. The biggest challenge is the ground measurement tools, by highly-expensive ground stations limiting the coverage of estimations. To accelerate the process and reduce costs, the work of Saleem explored the application of machine learning and deep learning algorithms to estimate PM2.5 using multiple sources like satellite retrievals of Aerosol Optical Depth (AOD) and other auxiliary data, such as meteorological data, land cover, land use, among others.