Dear SEDAG Members:
it is our pleasure to invite you to submit an abstract for a platform and/or poster presentation in the session on Future challenges in sediment toxicity testing for environmental risk assessment (under track 4-Ecological Risk Assessment and Human Health Risk Assessment of chemicals, other stressors and mixtures) at the next SETAC Europe Annual Meeting in Brussels, Belgium, 7-11 May 2017. You will find the session summary at the end of this message.
Please note that the deadline for submission will be November 23, 2016.
Thanks in advance for your interest.
We are really looking forward to reading your abstract and hopefully to seeing you at the SETAC Europe 2017 Annual Meeting in Belgium!
Your Sessions Chairs,
Daniel Faber - Bayer CropScience AG
Paul Sibley - School of Environmental Sciences, University of Guelph
Theo Brock – Alterra, Wageningen University and Research
Hank Krueger - Wildlife International
Sediment toxicity testing is gaining an increasing awareness within the scientific community. In 2015, a scientific opinion on environmental risk assessment for sediment organisms was published by the European Food Safety Authority (EFSA)1. This scientific opinion is of high interest for risk assessors and aquatic ecotoxicologists because so far, only the Tier 1 risk assessment for sediment organisms was addressed in the existing aquatic guidance document published in 2013 by EFSA2. In addition the European CHemicals Agency (ECHA) updated the sediment part of the “Guidance on Information Requirements & Chemical Safety Assessment”3 in February 2016. The number of currently available standardized and validated OECD guidelines is limited. These tests mainly cover invertebrates (e.g. Chironomus riparius, Lumbriculus variegatus). One adopted guideline on a sediment test with the macrophyte Myriophylum is available. In addition, a few ISO sediment guidelines are available, e.g. for the nematode Caenorhabdites elegans. 4
In North America, sediment toxicity is considered differently within the risk assessment as reflected by the ASTM and US EPA guidelines. In addition, a higher number of standardised test methods are available (e.g. Hyalella azteca, Chironomus dilutus, Leptocheirus plumulosus). There are a number of important differences between the OECD and US EPA guidelines5, including the use of field collected or artificial sediment, equilibration time, and flow-through or static test design. These test method differences lead to changes in the physico-chemistry of the sediment, in the bioavailability of the test compound, and the concentrations of the test substance in the overlying water, pore water, and bulk sediment. Due to these differences, the test results of studies performed according to OECD and US EPA test methods are difficult to compare.
In recent years, it has been discussed which matrix (pore water, water, sediment, bulk sediment, total loading) should be used to determine effects endpoints. Most test organisms are epi-benthic and live on the sediment surface and not within the sediment. A clear correlation between pore water concentrations and observed effects does not exist. Therefore, being aware of discrepancies between OECD and North American methods on the one hand and between EFSA and ECHA guidances on the other hand, some common issues need to be considered, including the relevant route of exposure, as well as how to express test results to be used in the risk assessment.
Within the session, we will address the differences between the guidelines and the consequences of the different approaches for an ERA using data from both sources and guidance. As the bioavailability in the different test systems is not directly comparable and different main uptake pathways exist for the different taxonomic groups and species, it should be discussed whether approaches as lined out in the scientific opinion are practically feasible.
1“Scientific Opinion on the effect assessment for pesticides on sediment organisms in edge-of-field surface water” EFSA, 2015
2“Guidance on tiered RA for plant protection products for aquatic organisms in edge-of-field surface waters” EFSA, 2013.
3 “Guidance on Information Requirements & Chemical Safety Assessment” ECHA, 2016
4 “International Organization for Standardization guideline 10872, 2010”
5 “Toxicity Testing and Ecological Risk Assessment Guidance for Benthic Invertebrates” US-EPA, 2014