The European Union Water Framework Directive (WFD) requires rigorous monitoring of contaminant levels in aquatic systems to assess their chemical status. However, traditional sampling methods have significant limitations in highly dynamic environments — such as estuaries and coastal areas — where water masses are constantly changing.
These conventional techniques provide only a snapshot of water conditions at a given moment and do not capture the spatial and temporal variability of contaminants. As a result, they may provide a poorly representative assessment of the actual toxic risk to the marine environment, making effective environmental management and compliance with European objectives more difficult.
Through the MONITOOL project, AZTI worked alongside seven other European research centres on the validation of passive sampling devices (PSDs) as an alternative to traditional methods.
These devices continuously accumulate chemical contaminants over a defined period, providing a much more representative estimate of actual contamination in the marine environment than spot sampling. They are also simpler and cleaner techniques, as they reduce sample handling in the laboratory and therefore the risk of cross-contamination.
In total, concentrations of cadmium, nickel, lead, aluminium, cobalt, copper, chromium, iron, manganese, silver and zinc were analysed in more than 700 water samples using three different techniques.