title: Acute toxicity tests with Daphnia magna, Americamysis bahia, Chironomus riparius and Gammarus pulex and implications of new EU requirements for the aquatic effect assessment of insecticides.
abstract: Threshold concentrations for treatment related effects of 31 insecticides, as derived from aquatic micro-/mesocosm tests, were used to calibrate the predictive value of the European Tier-1 acute effect assessment on basis of laboratory toxicity tests with Daphnia magna, Chironomus spp., Americamysis bahia and Gammarus pulex. The acute Tier-1 effect assessment on basis of Daphnia (EC(50)/100) overall was protective for organophosphates, carbamates and most pyrethroids but not for neonicotinoids and the majority of insect growth regulators (IGRs) in the database. By including the 28-day water-spiked Chironomus riparius test, the effect assessment improves but selecting the lowest value on basis of the 48-h Daphnia test (EC50/100) and the 28-day Chironomus test (NOEC/10) is not fully protective for 4 out of 23 insecticide cases. An assessment on basis of G. pulex (EC(50)/100) is sufficiently protective for 15 out of 19 insecticide cases. The Tier-1 procedure on basis of acute toxicity data (EC(50)/100) for the combination of Daphnia and A. bahia and/or Chironomus (new EU dossier requirements currently under discussion) overall is protective to pulsed insecticide exposures in micro-/mesocosms. For IGRs that affect moulting, the effect assessment on basis of the 48-h Chironomus test (EC(50)/100) may not always be protective enough to replace that of the water-spiked 28-day C. riparius test (NOEC/10) because of latency of effects.
authors.affiliation: Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, The Netherlands. theo.brock@wur.nl
authors.forename: Theo C M
authors.initials: TC
authors.lastname: Brock
authors.forename: René P A
authors.initials: RP
authors.lastname: Van Wijngaarden
mesh_terms: D033304:Amphipoda / Q000187:drug effects; D000818:Animals; D002219:Carbamates / Q000633:toxicity; D002683:Chironomidae / Q000187:drug effects; D003621:Daphnia / Q000187:drug effects; D033364:Decapoda; D007306:Insecticides / Q000592:standards / Q000633:toxicity*; D007605:Juvenile Hormones / Q000633:toxicity; D010755:Organophosphates / Q000633:toxicity; D011722:Pyrethrins / Q000633:toxicity; D023382:Toxicity Tests, Acute / Q000379:methods* / Q000592:standards; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D002219:Carbamates; D007306:Insecticides; D007605:Juvenile Hormones; D010755:Organophosphates; D011722:Pyrethrins; D014874:Water Pollutants, Chemical