Method for reconstructing the initial baseline relationship between potentially harmful element and conservative element concentrations in urban puddle sediment

This paper presents a method for reconstructing the initial baseline relationship between potentially harmful element (PHE) and conservative element (CE) concentrations in urban puddle sediment samples. This method is based on an analysis of the relationship between PHE and CE concentrations in urban puddle sediment samples a considerable time after landscape development. After development, pollution increases the PHE concentration and changes the initial PHE-CE relationship. The ultimate goal is to restore it taking into account environmental pollution. The approach is to assign lower weights to more polluted samples and apply linear weighted fitting. To test the developed method, reconstruction of the initial baseline PHE-CE relationship was performed by applying the results of a survey of PHE concentrations in contemporary urban puddle sediments in Ekaterinburg, Russia, in 2007-2010. The reconstructed relationships between the PHE (mg/kg) and CE (Fe, g/kg) concentrations are as follows: Pb = 45 + 0.1·Fe, Zn = 141 + 1.7·Fe, and Cu = 32 + 1.2·Fe. The developed approach demonstrated consistency with results of the 137Cs chronological tracer approach for Pb, Cu, and Zn pollution.