Bioavailability of Cu in freshly spiked, leached and field-contaminated soils

Long-term ageing processes which could cause the bioavailability of Cu to decrease with time in the field does not occur in laboratory spiked soils usually used for assessing the risk of trace elements. This study compares bioavailability of Cu both in spiked soils as well as in leached and equilibrated soils after spiking to fieldcontaminated soils using rhizon extracted pore water, CaCl2 extraction and the calculation of soil-liquid partitioning coefficients-Kd. Bacterial-bioluminescence biosensors were used for ecotoxicological verification. Leached soils revealed ranges for properties of their pore water (dissolved organic carbon, soluble Cu, complex Cu, free Cu^2+, % of free Cu^2+, Kd) to be closely related to the field soil unlike the spiked soils. However, lack of Cu toxicity in the field soil prevented an estimation of the magnitude the leached soils could be related. Leached and equilibrated metal data can be used in ecological risk assessment with scrutiny.