Species non-exchangeability for ecotoxicological risk assessment

Hickey, Graeme ORCID: 0000-0002-4989-0054 and Craig, Peter S
(2009) Species non-exchangeability for ecotoxicological risk assessment. [Poster]

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In aquatic based chemical risk assessments, there is a wealth of statistical techniques for use in lower tier risk assessment. In particular, we focus on estimation of the hazardous concentration to x% of an ecological community (HCx); a concept based on the idea of Species Sensitivity Distribution (SSD). The SSD is typically assumed to act as a proxy distribution to model the inter-species variation in the biological assemblage. Over time, a number of criticisms have been made of the SSD concept, but we focus on one in particular – species non-exchangeability. The concept was first discussed within a semi-probabilistic setting by an opinion of the European Food Safety Authority (EFSA) Scientific Panel on Plant Production products and their Residues (EFSA Journal, 2005). We build on their findings to demonstrate, statistically, that the Rainbow trout (Oncorhynchus mykiss) is not exchangeable with other species. By this term, we mean that, a priori, before observing the toxicity value of the species, we do not believe it to be a realisation from the same distribution as the other species in the assemblage. In fact, the Rainbow trout is typically more sensitive than the average fish species across a wide range of substances. In addition, we briefly demonstrate how to exploit historical databases of toxicity data featuring the Rainbow trout to quantify this non-exchangeability in order to derive new estimators for the HCx.

Item Type: Poster
Depositing User: Symplectic Admin
Date Deposited: 27 May 2015 08:34
Last Modified: 17 Dec 2022 01:45
URI: https://livrepository.liverpool.ac.uk/id/eprint/2012067