Discharge water samples from Exhaust Gas Cleaning Systems (EGCS, scrubbers) were taken on board of ships and analyzed in terms of heavy metals and PAKs.
The distribution of wash water and potential concentration of pollutants were simulated with a dispersion model for the North- and Baltic Sea. Results showed increased pollutant concentrations, especially in the closed-loop EGCS waters, and that the accumulation of pollutants can be significant in some areas of the Baltic.
The study concludes that EGCS may improve the air quality in harbor cities and at sea but will shift atmospheric to marine pollution.
The findings are integrated into international discussions at IMO, EU and HELCOM with the view to reduce marine pollution caused by scrubber discharge waters.