The pollution of the River Rhine with heavy metals

Abstract

Since the early 1970s the heavy-metal content of the Rhine has gone down considerably. Especially the point sources have become less important. The background pollution counts are around 20% for Pb and Zn, >20% for Hg and Cd, 40% for Cu, 50% for Cr, and 60% for Ni. As a third source diffuse pollution (rain, surface erosion, etc) plays a role especially with Zn, Cd, Pb. The analytical procedures for evaluating metal concentrations are in some cases no longer sensitive enough to control the very low metal content. -Author