2. |
- Gustavsson, Mikael, et al.
(author)
-
Using species sensitivity distributions to determine boundaries for chemical pollution
- 2015
-
In: Oral presentation at the SETAC conference, Barcelona, Spain.
-
Conference paper (other academic/artistic)abstract
- Species sensitivity distributions (SSDs) and distributions of toxicity values are used for determining toxicological and ecotoxicological thresholds, the HC5 (hazardous concentration for 5% of the species) and the TTC (threshold of toxicological concern), respectively. An SSD describes the sensitivity distribution of a range of species towards a single toxicant, while the TTC is based on the toxicity distribution of a range of different compounds towards the same species or group of species. Both concepts can be combined by using the distribution of HC5 values for a group of substances in order to estimate the TTC. HC5- as well as TTC-values are usually based on toxicity data from standard single species assays. However, the ecological impact of a compound is the result of the reaction of a range of interacting species. In order to explore the impact of using data from ecological communities instead of single species, we performed a comparison of the TTC based on HC5-values with the TTC based on community ecotoxicological data (threshold of concern for community toxicity, TCCT). This study was performed by using toxicity data for Photosystem II- inhibiting herbicides to single algal species and algal communities. Single-species based SSDs and the corresponding HC5 values were established for seven different herbicides. Community ecotoxicity data were collected for 17 herbicides. The resulting thresholds were 6.8 nmol/L for the TTC based on HC5 values and 3.5 nmol/L for the TTC based on community data. This indicates that indirect ecological effects and species interactions do not seem to play a major role, as long as photosynthesis is in focus.
|
|