Lead in the urban environment — Studying the strong decline in Germany

Two matrices were selected representatively demonstrating the lead contamination history in the German urban environment: Lead concentrations in sewage sludge ash were reported for the period between 1972 and 1992 exhibiting a reduction of 88% down to a relative level of 0.12 in 1992 (1972 = 1). Additionally, samples of common grass in proximity to a motorway were analyzed in 1973 and 1992 and show a decrease of 85%. The whole of German efforts in reducing lead input is reflected in the samples. Alkyl leaded gasoline consumption data, which show a relative decrease down to 0.076 (92.4% less) in the same period, were compared with the measured values in grass and in sewage sludge ash. The “delay” in the environmental response is discussed.