May 30, 2022 by Adam Peters
I moderated a topical discussion at SETAC Copenhagen on the European Commissions Chemical Strategy for Sustainability and how it relates to metals with Steve Lofts (CEH), Chris Cooper (IZA), and Stijn Baken (ICA) on the 16th May. This generated some interesting discussion and the main points raised are summarised below.
The Chemical Strategy is about demonstrating the safe use of chemical substances. Overall it is extremely important to consider exposures as well as the hazard, and it is extremely important to consider the ecological relevance of the measures taken.
Tests for endocrine disrupting substances and the overall testing strategy for them need to be applicable to metals.
There is a need to develop invertebrate tests for endocrine disruption for all substances, but especially for metals because for many metals the vertebrate species that have previously been the main focus of attention are much less sensitive to metal toxicity than other organisms.
Adverse outcome pathways may be extremely complex for many metals, but this complexity cannot be avoided and will need to be addressed. It may be possible to simplify these assessment initially to provide a basis to build upon.
There is a great deal of uncertainty surrounding mixtures of substances in the environment and there will not be any prior exemptions from the application of a mixture assessment factor.
The main justifications surrounding the need for a mixture assessment factor are derived from modelling.
Combined exposures will inevitably occur in the environment, but there are also multiple stressors and pressures on the environment. These issues make understanding the implications of real exposures extremely complicated.
The bioaccumulation of metals is important, but this must take account of environmentally and ecologically realistic conditions.
It is important that all studies are fully reported so that their applicability can be properly evaluated.
It is important that the information provided by all sources is evaluated objectively based on its merits, and unjustified positions should not be accepted from any parties.