Chemical composition of Lake Maggiore sediments

The changes in sediment chemical composition of Lake Maggiore (Italy) have been traced by collecting a series of grab samples in 1962-63, 1975, 1986, and 1999. The map of distributions of Si, Al, Ca. K, Fe, Mg, Ti, S, P, Pb, Zn, Cu, Ni, Mn, Cr, Cd, Hg, Sc, Co, As, and V, allows identification of hot spots which can be related either to geological features or point sources of industrial pollution.