ABSTRACT
The proposed use of equivalence tests instead of difference tests in the revised guidance on the risk assessment of plant protection products for bees is a reasonable approach given an adverse effect was observed in the lower tier studies, using the hypothesis that there is a risk as the null hypothesis places the burden to prove the opposite on the other side. However, some uncertainties regarding the application of equivalence tests in field studies are discussed in the present study. Here, we compare equivalence and difference testing methods using a control dataset of a honey bee field effect study conducted in northern Germany in 2014. Half of the 48 colonies were assigned to a hypothetical test item group, and the colony strength data were analyzed using t-tests, a generalized linear mixed model (GLMM), and the corresponding equivalence tests. The data reflected the natural variability of honey bee colonies, with initially approximately 12 000 adult bees. Although the t-test and GLMM confirmed that 24 + 24 colonies are sufficient to show "no adverse effect," the equivalence tests of the t-test and GLMM were not able to reject the null hypothesis and classified at least some of the assessments as "high risk," indicating a power that was too low. Based on this, different operating options to reduce the variability are discussed. One possible option, which may provide a more realistic application of equivalence to avoid false high risk, is to consider the lower confidence interval of the control as a baseline and use GLMMs. With this option, we demonstrate a relatively acceptable probability to prove that no high risk for initially similar groups can be achieved. Further studies with different numbers of colonies are still needed to develop and validate the suggested approach. Integr Environ Assess Manag 2024;00:1-8. © 2024 SETAC.
ABSTRACT
Trapping small mammals is frequently used to study the dynamics, demography, behavior and presence of pathogens. When only particular small mammal species are in the focus of interest, all other species are unnecessary bycatch. We analyzed data from extensive live trapping campaigns conducted over the last decade in Germany, following a consistent standard trapping protocol that resulted in about 18,500 captures of small mammals. Animals were trapped with Ugglan multiple capture traps in grassland, forest and margin habitat. Trap success and the proportion of bycatch were about 30% when target species were common voles (Microtus arvalis) in grassland and common voles and bank voles (Clethrionomys glareolus) in margins and forests. This was more pronounced in spring and along margins. Species mentioned in the early warning list according to the Red List Germany were higher in numbers and proportion in spring and in grassland. The results will help to avoid periods with enhanced presence of bycatch, including endangered species (if the purpose of the study allows) or to pay particular attention in certain seasons and habitats when the occurrence of bycatch is most likely.
ABSTRACT
According to the European legislation, REACH, organic compounds are considered as substances of very high concern (SVHC) if they are persistent, bioaccumulative and toxic (PBT). A substance's long-range transport potential (LRTP) may also pose a risk to remote regions. This is, however, not yet explicitly included. For identification of compounds, which are not PBT according to REACH criteria, but show LRTP, we investigated 22,438 compounds from the Canadian Domestic Substance List (CDSL). The CDSL was searched for organic, neutral compounds. Substance properties were estimated with EPI Suite v4.00. Next, the substance list was edited in two ways: (1) The half-life criterion in air for LRTP as defined in the Stockholm Convention was applied. (2) For all compounds, indicators for persistence and LRTP were calculated with the multimedia model ELPOS v2.2. Applying the half-life criterion, we identified 594 substances, which are prone to LRT but are not PBT (non-PBT-L substances). In contrast, investigations with ELPOS lead to a shorter list of 188 substances, which are non-PBT-L substances. Finally, the list was compared with potential Arctic contaminants identified in previous literature. Our results show that there is a large number of organic chemicals which would not be considered as SVHC since they are not, at the same time, persistent, bioaccumulative and toxic according to REACH criteria. Nevertheless, they show LRTP according to different screening approaches and thus a potential hazard to remote regions.
