Trace element concentrations have been collected since 1994 in Lake Geneva, Switzerland as part of a water-quality monitoring program set up by the Service de l’Ecologie de l’Eau (SECOE). This dataset has been used to detect trends in freshwater trace element concentrations. Changes in direction of the trend during the sampling period are apparently visible for some elements. Turning year was 2001 for Pb. All data concentrations and integrated element load (IEL) for Pb decrease in all periods, although the change in IEL is not significant in the first period once the Hamed and Rao correction was applied.
J.C. Rodríguez-Murillo, P. Nirel and M. Filella, Detecting trends in freshwater trace element concentrations: methodological issues and data treatment. H2Open Journal, 1, 87–89 (2018). doi:10.2166/h2oj.2018.006.
The transport into sediments of the trace elements Cu, Zn, Pb, Cd, Cr, and Sr by settling particles in Lake Zurich studied through the measurement of the concentrations of these elements in settling particles collected in sediment traps and in the water column at different times of year.
L. Sigg, M. Sturm and D. Kistler, Vertical transport of heavy metals by settling particles in Lake Zurich. Limnology and Oceanography, 32, 112–130(1987). doi:10.4319/lo.1987.32.1.0112.