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. 2021 Feb 17;195:110863. doi: 10.1016/j.envres.2021.110863

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Fig. 2 — a) Meteorology (Temperature, Precipitation, Wind speed, relative humidity) and b) particulate matter (PM10, PM2.5 and PM1) concentrations during April and May in Madrid. Natural processes like Saharan dust outbreaks and sampling periods are shown.