The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

摘要: Abstract A scientific research program was initiated by the International Molybdenum Association (IMOA) which addressed identified gaps in environmental toxicity data for molybdate ion (MoO 4 2 − ). These were previously during preparation of EU-REACH-dossiers different molybdenum compounds (European Union regulation on Registration, Evaluation, Authorization and Restriction Chemical substances; EC, 2006). Evaluation open literature few reliable marine ecotoxicological that could be used deriving a Predicted No-Effect Concentration (PNEC) environment. Rather than calculating PNEC using assessment factor methodology combined freshwater/marine dataset, IMOA decided to generate sufficient chronic permit derivation means more scientifically robust species sensitivity distribution (SSD) approach (also called statistical extrapolation approach). Nine test chronically exposed (added as sodium dihydrate, Na 2 MoO ·2H O) according published standard testing guidelines are acceptable broad range regulatory purposes. The selected organisms representative typical trophic levels: micro-algae/diatom ( Phaeodactylum tricornutum , Dunaliella tertiolecta ), macro-alga Ceramium tenuicorne mysids Americamysis bahia copepod Acartia tonsa fish Cyprinodon variegatus echinoderms Dendraster exentricus Strongylocentrotus purpuratus ) molluscs Mytilus edulis Crassostrea gigas Available NOEC/EC 10 levels ranged between 4.4 mg Mo/L (blue mussel M. 1174 mg Mo/L (oyster C. Using all available effects currently available, HC 5,50% (median hazardous concentration affecting 5% species) 5.74 (mg Mo)/L derived with approach, value can national international