Cd, Co, Cu, Ni, Pb, Zn in coastal and transitional waters of Greece and assessment of background concentrations: Results from 6 years implementation of the Water Framework Directive

Dissolved trace metal concentrations were determined in coastal and transitional waters during 6 years (2012 to 2015, 2018, 2019) of monitoring for the implementation of the EU Water Framework Directive (WFD) in Greece. In this work we provide an assessment of background concentrations for dissolved metals in saline water bodies at 3 geochemical-climatic zones of Greece and estimate the upper background concentrations (BAC) for each zone (z1, z2, z3), as follows: z1: 0.022 mu g L-1, z2: 0.018 mu g L-1, z3: 0.016 mu g L-1 for Cd; z1: 0.072 mu g L-1, z2: 0.081 mu g L-1, z3: 0.057 mu g L-1 for Co; z1: 0.420 mu g L-1, z2: 0.591 mu g L-1, z3: 0.531 mu g L-1 for Cu; z1: 0.808 mu g L-1, z2: 0.928 mu g L-1, z3: 0.841 mu g L-1 for Ni; z1: 0.415 mu g L-1, z2: 0.383 mu g L-1, z3: 0.421 mu g L-1 for Pb; z1: 3.19 mu g L-1, z2: 3.59 mu g L-1, z3: 3.01 mu g L-1 for Zn. Coastal and transitional water bodies are classified in relation to the BAC of each zone revealing a diminishing order Ni > Cu > Pb > Co > Cd > Zn for metals concentrations >BAC, showing clearly that Ni and Cu contamination affects the highest number of water bodies. Overall, transitional water bodies of estuaries and wetlands of high biodiversity were found more affected by metal contamination than coastal water bodies. Our work contributes to the assessment of background concentrations for metals and the development of Environmental Quality Standards (EQS) on the EU, regional or individual country level. Specifically, for Greece, it provides the first dataset towards this direction, and highlights Cu as a priority metal. Thus, our work contributes to the implementation of both the WFD and theMarine Strategy Framework Directive (MSFD). (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study in Greece evaluated the dissolved trace metal concentrations in coastal and transitional waters over a 6-year period. It found that Ni and Cu contamination affect the highest number of water bodies, with transitional water bodies of estuaries and wetlands being more affected by metal contamination than coastal water bodies. The research contributes to the development of Environmental Quality Standards (EQS) and the implementation of the EU Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD) in Greece.