Regional and Long-Term Patterns of Lead Concentrations in Riverine, Marine and Terrestrial Systems and Humans in Northwest Europe

Lead contamination of abiotic and biotic systems has beenstudied closely since the early 1970s, when lead was firstperceived as an environmental problem. Lead emission reductionpolicies were implemented throughout Europe during that time.Nonetheless, analyses of lead loads in aquatic systems, such asthe River Elbe, showed no decline over time in either suspendedmatter or surface sediments. Regional differences in leadconcentrations of fluvial, i.e. riverine systems were found,due to tidal influence, runoff and local emissions. Leadcontamination of sediments from the North Sea was highest inestuaries. Concentrations in sediment cores were quite stabledown to the depth of background values, due to bioturbation,flow, waves and meandering channels. Terrestrial soils inEurope were highly polluted in industrial and ore mining areasand large cities. No decline in lead concentrations was evident in foraminifera,bladder wrack or fish. It was found that contamination insediments, mammals and fish livers was higher in coastal zonesthan in the open sea. In contrast to aquatic organisms,positive impacts of lead reduction regulations were detected interrestrial plants, which adsorbed or took up lead mainlythrough atmospheric lead deposition. European leadconcentrations in plants decreased coincidently with leademissions. That trend could also be identified in the bloodlead levels of the human population in Europe: since 1979 theyhave declined in every group of the population. Mainlyinfluenced by age, sex and the living environment, overall, thelead loads of humans had never been high enough to cause healtheffects.