*Better communication between researchers, environmental agencies, and the shipping industry
There is today a lack of communication between different scientific disciplines, and between scientists, the shipping industry, and authorities, which leads to situations where important existing research data, in this case data on PACs toxicity, are not being taken into account in decision-making. There is a great need for more efficient transfer of knowledge between researchers working on the toxic mechanisms of PACs and those conducting experiment aimed for risk assessments, and also between the scientific community, national and international environmental and transportation agencies, the shipping industry and other relevant stakeholders.
*Risk assessments of scrubber water should be based on tests with whole scrubber water, but selection of relevant endpoints should be based on chemical composition of the water and toxicity data on detected compounds
Scrubber water contains a complex mixture of compounds that may be toxic by themselves but also interact with each other and cause synergistic effects. The best method to test the toxicity of scrubber water, and other complex wastewaters (sometimes also called whole effluent toxicity, WET), is therefore to perform tests on whole scrubber water. However, in order to select relevant and sensitive endpoints in the scrubber water tests, knowledge on what compounds the water contains and what toxic effects these compounds have is needed. Refinement of analytical methods so that a wider spectrum of PACs may be detected together with more basic research on toxicological effects of PACs on marine species to derive more refined LOECs and ECs is therefore crucial.
*Endpoints in ecotoxicological testing of scrubber water should be based on the most sensitive endpoints that have an impact on a population level
Most standardised ecotoxicological protocols today are overly simplistic and there is a risk that the data generated underestimate the environmental risk of the test compounds/mixture of compounds. Endpoints in ecotoxicological tests used for risk assessment should be based on effects that are likely to have an impact on the population well-being, and the review of PAC toxicity presented in this report shows that there are many physiological endpoints that meet this criterion and that are more sensitive than those commonly used today. Much interesting research is also done on a genetic or molecular level where the impact on the organism is still unknown. These findings may not be applicable for the applied ecotoxicological tests of today but may form the basis for even more sophisticated endpoints to be used in the future.