Seasonal variations in the concentration and solubility of elements in atmospheric particulate matter: a case study in Northern ItalyS. Canepari, M. L. Astolfi, F. Marcovecchio, M. Maretto and C. PerrinoE3S Web of Conferences, 1 (2013) 20002DOI: https://doi.org/10.1051/e3sconf/20130120002