February 10, 2011 by Peter Simpson
Last week I attended the 3rd SETAC Europe Special Science Symposium, which was held in Brussels. The symposium was entitled the “Prospective and retrospective environmental risk assessment of mixtures: Moving from research to regulation”. The meeting was very well attended with delegates from across academia, government and non-governmental organisations, environmental regulators, environmental consultancy and the pharmaceuticals, metals and chemicals industry (including representatives from the bulk, agrochemicals and consumer chemicals sectors).
Plenary presentations were made across two days by a wide variety of speakers and are available for download from the SETAC website. My colleagues and I presented four posters at the meeting, which can be downloaded here:
- Should the receiving environment be considered a mixture in chemical risk assessment? – If so, how?
- Evaluation of tank mixing in British agriculture: Environmental implications
- Direct toxicity assessment (DTA) of mixtures in effluents: Current UK experiences
- Statistical approaches for distinguishing individual chemical toxicity thresholds in potentially complex mixtures
Whilst there was some general differences between the presenters, there appeared to be a remarkable consensus on a number of areas, such as:
- The use of the concentration addition (CA) model as a conservative first tier of mixtures assessment, even if this was based on PNEC data (which could contain a large safety factor) from across species, could be readily implemented in environmental risk assessment – but which mixtures should it be used to assess?
- The recognition that the majority of mixtures issues are likely to be the consequence of a few chemicals (the so called “dirty-dozen”).
- Synergism is considered to be relatively rare, although there are a number of documented instances in the scientific literature, which means that it cannot be forgotten about.
DG Environment have been actively involved in this policy area for a number of years and are currently consulting with the EU Scientific Committee on Health and Environmental Risks (SCHER) on the available and appropriate methods for addressing mixtures across European Chemical Regulation, such as REACH, Plant Protection Products and Biocides Directives. The SCHER are due to report back to DG Environment this summer.