Contrary to expectation, no indication of traffic emissions, i.e., through Pb concentrations mirroring the use of leaded gasoline, was found. Instead, the TE profiles of the lakes mirror emissions from industrial processes . Possibly, emitted Pb didn't reach the lakes or it had too little effect on the overall Pb concentration, so that it was masked by significantly higher industrial depositions. In Switzerland, cores from Lake Zurich showed rising Pb concentrations long before the introduction of leaded fuel , and in Lake Brêt the Pb profile roughly followed that of other studied elements, i.e., Cu and Hg . Both observations, which are present in the current study as well, were ascribed to an overall metal pollution from industrial activity as the major source.