The current bird and mammal guidance document used in the EU for plant protection product authorisations is being revised, having been in existence for >10 years. As part of this revision, a public consultation was undertaken in 2017 on the existing guidance, with a chance for all stakeholders to submit comments and highlight any areas where they felt improvements could be made etc. EFSA recently published the outcome of that consultation, with 410 comments being received from regulatory bodies, industry, consultancy, academia, NGOs and anonymous/other contributors. There are too many topics to report them all here so below we’ve tried to highlight some of the main themes from the comments that were submitted:
- Deriving ecologically relevant endpoints for wild mammals – more guidance on what constitutes an effect (statistical vs biological significance), magnitude of effect, types of effects that are relevant, which studies to take into account, the relevance of dietary vs gavage exposure routes, etc; CEA has published our experiences on this topic
- The use of historical control data (HCD) in the interpretation of standard toxicity studies; CEA recently co-authored a journal article on this topic
- The use of benchmark dose (BMD) modelling – a technique already used in human health risk assessments
- What information should be presented and how when attempting to waive the need for avian reproduction studies and risk assessments e.g. autumn uses outside of active breeding times
- Some stakeholders calling for more effect parameters to be measured in toxicity studies (e.g. neurotoxicity, behavioural effects, juvenile effects in birds) in case these more subtle effects are resulting in population level effects
- Duration of exposure in standard toxicity studies versus the predicted duration of exposure resulting from the proposed use and efate properties of the substance, particularly for seed treatments
- Using extrapolated LD50 values (from studies resulting in unbounded endpoints) in geomean calculations; update on any developments in using a geomean approach for NOELs (or requesting an alternative method for incorporating multiple species data on reproductive effects into the risk assessment) – CEA presented a poster on combining reproductive toxicity data from different avian species
- Combined toxicity – when is an assessment required (acute only or acute + repro?) and how to do it (CA approach?)
- Are bats covered by current risk assessment scheme; EFSA recently released a statement regarding bat risk assessment
- Additional crop scenarios to be added to the crop groupings e.g. rice, Christmas tree plantations, etc
- Various errors in the short-cut values for spray apps were highlighted
- How to assess whether short-term or long-term effects occurring and therefore which TWA factor to use – originally stated in EFSA (2009) that more guidance would be issued but this has never been published
- Relevance of the vole scenario to be revisited
- Use hare instead of rabbit as the default lagomorph as hare could be considered to be more vulnerable
- Suggestions for additional exposure routes to be included in the risk assessment e.g. dermal exposure
- Annex I shortcut values: many arguments presented for changes in scenarios e.g. mixed diet for voles rather than 100% grass; including updating using latest deposition factors from FOCUSgw (2014)
- Additional non-spray application methods to be included e.g. drip irrigation
- Granule risk assessment scheme: errors in units; further clarification of the scheme was requested; some stakeholders questioning whether all steps of the scheme are required in all cases as it is very complex
- Seed treatment risk assessment scheme: more guidance for weight of evidence approaches as seed treatments are less likely to achieve the same assessment factor as spray applications; uncertainty in extrapolation from the default mouse scenario to the rat 2-generation toxicity study is lower so could potentially use a lower assessment factor (as already done in some MSs); the time window used for TWA factors has been inconsistent (21-d ‘default’ vs 7-10 d germination time); additional refinement options to be included in the guidance document e.g. seed dissipation studies; clarification of what a large/small foraging area is for contextualising the risk
- Develop a ‘zonal’ set of refinement options for higher tier risk assessments as these, by their very nature, are more localised in their relevance e.g. focal species, diet composition, etc
- ‘Fix’ the non-substance specific parameters e.g. PT, PD and thus Notifiers would only be able to refine substance parameters e.g. DT50
- Refinement of residues and residue dynamics: update existing RUD database to include more recent trials and more crops (and to make it more transparent); more guidance for study design, number/distribution of sites needed to refine the DT50 and calculate a geomean, acceptability of rainfall occurrences, extrapolation between matrices/locations, on laboratory arthropod DT50 studies (how many species needed, etc), when RUDs can be refined, calculating moving window TWA/MAF values. It was suggested that the default 10 d DT50 is revisited based on recent industry data reviews. The UBA noted it has produced a concept paper on evaluating residue/residue decline studies for plants.
- Identification of focal species, a critical parameter for higher tier risk assessment
- Proportion of time spent in the treated crop (PT): more guidance needed regarding study designs (location, number of tracked individuals) as well as the criteria for selecting mean vs 90th percentile vs worst-case PT values and the use of consumer vs non-consumer data. The use of PT values over time (e.g. 21-d PT) should also be discussed in the new guidance.
- Proportion of diet (PD): consolidation of existing data; whether PD can be refined for acute and reproductive risk assessments is needed. More guidance on interpreting PD studies was requested, including the influence of units (volume, dry weight, wet weight) on PD.
- More recent data generated on dehusking; CEA has published a poster on calculating dehusking factors for birds and mammals
- Regulatory authorities called to remove avoidance as a refinement option
- Lack of validation and guidance for selecting input data and interpreting output data from body burden (BB) models; developments in BB modelling since the publication of the guidance in 2009 were highlighted
- Validity criteria for field effect studies; acceptance of such studies by regulators is variable due to a lack of guidance on acceptable study design and interpretation
- Role of semi-field/pen studies in risk assessment
- When and how to use wildlife incident data; the new guidance should also include all known sources of such data
- Population-level effect models: currently included in EFSA (2009) as a refinement option but acknowledged the need for commonly agreed models together with guidance on assessing the model outputs; various models have been developed since 2009 and the new guidance should include a review of these models, together with EFSA (2014) recommendations for good modelling practice; acknowledged the need for applicants to submit enough information about the model, the underlying data and testing for there to be confidence in the model output; CEA has co-authored a paper on modelling breeding success in birds potentially exposed to treated seed
- Reflect the new endocrine disruptor criteria and highlight the currently available study guidelines
- When and how metabolites should be assessed
- Calculation and consistency of drinking water assessment with other EU risk assessment schemes; implement a trigger for when this assessment is required as it rarely fails
- Clarification of input parameters needed and the scheme for metabolites for bioaccumulation/food chain risk assessment; confirm whether to use dry soil or pore water approach; further guidance needed on food chain modelling
- Characterising uncertainty/risk characterisation: considered important but rarely done due to being a complex process; needs to be revisited once new protection goals are defined; could be simplified and clarified as to what is actually needed; worked examples could be useful; more guidance needed on how to quantify uncertainty as can be subjective
- Updates to the various appendices were proposed
- Requests for a calculation tool to be developed, including moving window TWA*MAF calculations
If you want to hear more about the ongoing developments in the area of bird and mammal risk assessment, you may be interested in attending the bird and mammal poster corner session at SETAC Dublin that CEA is co-chairing on Tuesday 5th May 2020. You can find out more about the poster corner entitled ‘Refinement of the Risk to Birds and Mammals from Plant Protection Products: Higher Tier Studies and Approaches’ on the SETAC Dublin website.
In addition to the publications highlighted above, you can find all of CEA’s publications in our online library, including all the posters and platform presentations we have presented at conferences over the years, together with links to our journal articles. This includes our recent journal article entitled ‘Reflections on bird and mammal risk assessment for plant protection products in the EU: past, present and future’.
If you would like to discuss any of the points raised in this article, or if you are encountering any issues with your bird and mammal risk assessments, please feel free to contact Amy Brooks (Amy.Brooks@cea-res.co.uk).
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