Dissent in the Sediment? – Lake sediments as indicators of short- and long-range impact of anthropogenic activities in northeastern Germany

The suitability of lake sediment cores to reconstruct past inputs, regional pollution, and usage patterns of pesticides has been shown previously. Until now, no such data exist for lakes in eastern Germany. Therefore, ten sediment cores (length 1 m) of ten lakes in eastern Germany, the territory of the former German Democratic Republic (GDR), were collected and cut into 5-10 mm layers. In each layer, concentrations of trace elements (TEs) As, Cd, Cr, Cu, Ni, Pb, S, Zn, as well as of organochlorine pesticides (OCPs) were analyzed. A miniaturized solid-liquid extraction technique in conjunction with headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was used for the latter. Of OCPs, only transformation products of dichlorodiphenyltrichloroethane (DDT) were found. Congener ratios indicate a mainly aerial input. In the lakes’ profiles, several regional features and also responses to national policies and measures are visible. Dichlorodiphenyldichloroethane (DDD) concentrations reflect the history of DDT use in the GDR. TEs show a uniform progression over time. They follow a trans-regional pattern and are indicative of activity and policy making in West Germany before 1990 instead of those in the GDR. Lake sediments proved to be suitable to archive short- and long-range impacts of anthropogenic activity. Our data can be used to complement and validate other forms of environmental pollution long-term monitoring and check for the efficiency of pollution counter measures in the past.