Compared to the average geogenic background for the respective federal state in which a lake is situated , the concentrations of the elements found in the lake sediments were mostly higher (factors ca. 2-15), when taking the period of industrial activity into account. Where the concentrations are lower, at least a trend is visible. For example, in Lake AR, concentrations of Cd, Pb and Zn are well above background in the period between 1946 and 1986, by factors at peak concentration of 8, 3 and 4, respectively. Cr, however, is found mostly below background concentration, except in Lakes ST and WM (factor ca. 2.5). There, Cd, Cr, Pb and Zn rise above background levels starting from ca. 1893. For both lakes, there are reports of local glass producing industry in the 19 th century dumping substantial amounts of ash from wood burning into the lakes, which could be an explanation . Additionally, this visible increase starting in the second half of the 19 th century is present for most of the elements in the extended profiles and is probably due to the onset of industrialization in general, that has been reported in other studies from European lakes (e.g., , and which has been proposed as the beginning of the Anthropocene . A similar pattern can be assumed for the other lakes that were not dated as far back in time. Concentrations before that, i.e., in the deepest layers of these cores (Fig. and Online Resource Figs. S17-S19), are rather constant over a longer period of time and may be considered local background concentrations.