Since 1992 air pollution measurements have taken place at different sites within the Misox valley. Air pollution is especially high in the lower Misox valley and the fine dust (PM10) - Limits of the air quality control (LRV) are regularly exceeded. In order to avoid future overshoots, an action plan was adopted in 2014. For this purpose, Meteomatics AG and inNET Monitoring AG were commissioned by the Office for Nature and Environment Graubünden to determine the precise spatial spread of pollutants. During the measurements on the 6th and 7th of December 2016 the altitude dependency of the pollutant load was one of the measured parameters, as described in the following report: