Ground based in situ observations of nephelometer at Ispra (IT0004R). These measurements are gathered as a part of the following projects ACTRIS, EMEP, GAW-WDCA, EUSAAR and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: aerosol_light_backscattering_coefficient in pm10, aerosol_light_scattering_coefficient in pm10