There is increasing focus on the identification of substances that are persistent (P), bioaccumulative (B) and toxic (T). Organisations involved with the assessment of persistence include UNICE, UNEP, OSPAR and the EU. It is clear, however that in many of the discussions, although persistence may be defined by assigning half-lives within different environmental compartments, a number of unknowns exist such as the relevance of the criteria, the extent to which they can be measured and the level of variability that exists within the environment. Whilst there are suitable standardised laboratory tests available to measure B and T there is an urgent need to develop test(s) that will allow the effective identification of substances that meet the regulatory criteria adopted to categorise persistence (P). Bioavailability and the limitations of current testing have been reviewed in a recent ECETOC report. It is important that if controls and regulations are to be put in place addressing persistent chemicals, that data are available which allows for informed scientific judgements. The tests developed in this research programme should offer improved environmental realism and be suitable for integration in the strategy proposed by ECETOC to assess the biotic aspects of persistence.
Design new laboratory tests for assessing biodegradation of low bio-availability chemicals at environmentally realistic concentrations, i.e. in the microgram per litre range. Factors that should be considered are the role of inoculum source, adaptation, growth linked and non-growth linked degradation. Ideally the measurements should be a-specific e.g. molecular ecology, CO2 and O2, however, specific measurements or use of radiolabelled material is not precluded. The performance of the new test(s) should be evaluated using a selection of poorly soluble and/or high absorptive organic chemicals, e.g. ionically charged molecules. Chemicals on the current PBT list proposed by OSPAR and ECB should be considered as a priority. On the basis of the data generated for the selected chemicals evaluate the potential for degradation using the new methodologies compared to existing test data and develop guidelines to improve the way that persistence of poorly bio-available chemicals is currently evaluated.
Proposals submitted for consideration should address the following areas under individual sub-headings:
- The title of the research proposal;
- The name and affiliation of the principal investigator and the laboratory or laboratories in which the research will be conducted;
- Evidence of the principal investigator's knowledge of, and contribution to, current understandings of persistence and how it may be measured;
- A clear definition of the research objectives, including a description of the mechanistic basis for the proposed research;
- A clear plan of investigation, including a clearly defined milestone plan which identifies all critical decision points in the research programme;
- A detailed breakdown of costs.