A Deterministic Ecological Risk Assessment for Copper in European Saltwater Environments

The objective of this study was to conduct a deterministic aquatic ecological risk assessment of copper in surface waters (saltwater) of Europe. A Hazard Quotient (HQ) approach defined as the Observed Environmental Concentration (OEC)/Predicted No Effect Concentration (PNEC) was used to measure risk. Hazard Quotients greater than one suggest ecological risk and/or the need for additional analysis (probabilistic analysis) or data collection. The dissolved copper concentrations used for the OEC values came mainly from areas of the Mediterranean Sea, the Baltic Sea, and the North Sea and consisted of measured copper concentrations from eight studies in marinas/harbors, ten studies in estuaries, and twenty-two studies in open sea regions. In a majority of cases, the geometric mean of the individual measurements was calculated to represent the typical concentration of dissolved copper expected to occur at that site. The overall geometric means of dissolved copper concentrations were 1.53, 1.49, 0.68 and 1.07 μg/l for pooled marinas/harbors, estuaries, coastal/open sea, and all sites, respectively. Maximum mean values by station type were 16, 5.48 and 5.56 μg/l for marina/harbors, estuaries and open sea/coastal areas, respectively. These copper exposure data are for total dissolved copper and reflect copper contributions from all sources of copper such as natural erosion of earth crust, mining and smelting, municipal and industrial wastewater effluents, pesticides, and antifouling paints. The ecological effects data used for the PNEC were determined from 65 saltwater species (five plants; 36 benthos; 8 zooplankton; and 16 fish) tested in acute studies. The acute 5th percentile (PNEC) for all species (protection level of 95%) was 5.6 μg/l. Hazard Quotients greater than one were only reported for 3 of 101 stations. All three stations were located in marina areas of either Saronic Gulf of Greece or Arachon Bay of France. Results from this risk assessment demonstrate that the probability of ecological risk from acute dissolved copper exposures in European saltwater environments is generally low.