Effect studies of new hormone active substances on aquatic snails Potamopyrgus antipodarum

Effect studies of new hormone active substances on aquatic snails Potamopyrgus antipodarum In the recent study, two endocrine active substances for human use, the progestin Dienogest and the glucocorticoid Dexamethasone, were tested in a 28-day reproduction test with the New Zealand mud snail Potamopyrgus antipodarum according to the OECD guideline 242. In a ring test in 2016, in which the Fraunhofer IME successfully participated, the OECD test guideline 242 was validated in order to broaden the range of test methods for investigations of e.g. endocrine active substances and their endocrine and reproductive toxic effects on aquatic invertebrates, particularly on water snails as they are proved to be sensitive towards endocrine disruptors (EDs). Until then the focus in testing of EDs was mainly on studies with fish. The results of this study will be used to establish a tailored evaluation concept for environmental risks for progestins and artificial glucocorticoids.
In the reproduction test with Dienogest analytically verified concentrations of 6.97, 11.2, 25.6, 106 and 332 ng/L were introduced. After 28 days, no significant effect on any of the investigated endpoints was observed. The NOEC for eproduction (in terms of total, shelled and unshelled embryos), survival and length were therefore determined to be ≥ 332 ng/L, respectively. The reproduction test with Dexamethasone was performed with analytically verified concentrations of 1.06, 3.54, 10.5, 36.3 and 105 µg/L. After 28 days, no significant effect on reproduction, survival and length occurred, resulting in a NOEC of ≥ 105 µg/L, respectively.