Chairman: Professor J G Ayres
Members: Ms A Baker, Dr M McPherson, Prof C Brown, Prof C Ockleford, Prof G Hawksworth, Dr D Osborn, Dr A Leake, Dr W Parker, Prof L Maltby, Dr A Povey, Prof P Matthiessen, Dr D Ray.
Assessors: Dr C Griffiths ( SASA), Mr M Williams (Welsh Assembly Government, WAG), Mr M Ward (PSD)
Advisers: Mr R Davis (PSD), Dr J Roberts ( Defra), Mr B Maycock ( FSA), Dr K Wilson (PSD)
Secretariat: Ms J Wilder (PSD) Secretary, Mr P Fisher (PSD) Minutes secretary, Miss A MacGregor (PSD) Secretariat
Other attendees: Mr A Dixon (PSD), Mr D Richardson (PSD), Mr R Mason (PSD), Mr M Roberts (PSD), Dr M Groom (Ecospray), Mr D Sadler-Bridge (Ecospray), Dr R Neilsen ( SCRI -for Ecospray)
1.1 Apologies were received from: Dr J Cherrie, Prof C V Howard, Ms R Howell, Prof J Parry, Dr H Rees, Ms G Asbury (FSA), Dr M Camlin (DARDNI), Mr S Dyer (DH), Mr G Wilson (HSE), Mr J Battershill (HPA), Dr J Best (NE), Dr T Boucard (EA), Dr L Hetherington (HPA), Dr R Turner (HSE)
2.1The Chairman reminded Members of the confidentiality of the papers and their discussions. If Members believed that they had a commercial or financial interest in any of the items being discussed, they should declare their interest as soon as the meeting moved on to that agenda item. They would then not take part in the discussion, nor would they be involved in any decision taking, unless invited to do so by the Chairman.
3. Agenda item 1:
3.1 a) 330th Meeting: Minutes [ ACP 1 (331/2008)]
3.1.1 Agreed as drafted.
3.2 b) 330th Meeting: Detailed record of discussion [ ACP 2(331/2008)]
3.2.1 Agreed as drafted subject to the clarification of an acronym.
4. Agenda Item 2: Secretary’s report [ ACP 3 (331/2008)]
4.1 The Secretary to the Committee reported that Ministers had accepted the advice given at the previous meeting.
5. Matters arising
5.1.1 Since the previous meeting PSD had joined HSE (on 1 April). They confirmed that the transfer had gone smoothly. Some details of the new arrangements remained to be finalised and some minor teething problems had been identified to be resolved. The next important steps were to explore how PSD and HSE could work more closely together to derive benefits and a small steering group and working group were to be set up to undertake this review. The review was to be completed within a year and the ACP noted their wish to be consulted in the course of this review.
5.1.2 Defra confirmed that the transfer had progressed smoothly from their point of view. They were working with PSD to ensure that the on-going relationship with Defra and respective responsibilities were clarified. It was confirmed that Defra retained the budgetary responsibility for PSD, including the R&D budget.
5.2 Members noted the progress on other matters arising from previous meetings.
6.Nemguard ACP 19 (331/2008)
6.1 Members recalled that they had considered this application for approval in November and had concluded that all aspects except efficacy were acceptable for approval. Members had identified the additional information required for approval. The applicant had appealed in writing against this advice in January and the Committee had concluded that there was no reason to change their previous advice. The applicant had now asked to present their case in person to the committee and had provided a body of data which included photographic examples of symptoms attributed to nematode damage, data on nematode population distribution patterns within and across fields and specifically a re-analysis of trials data using GLIM.
6.2 Members had read the written case also presented to the committee and summarised that it was clear that the active substance, garlic juice can cause mortality in nematodes in vitro. There was a small but inconsistent effect seen in some of the field trials, and interpretation of these trials was difficult for a number of reasons. The main concern was thus the unpredictability of effects in the field which made formulation of label recommendations extremely difficult. Whilst the product did seem to give some suppression of root damage on some occasions it was not possible to identify when the product might work in a crop –or indeed if it didn’t work to explain why not. The applicant suggested in their document that the variability in response was due to the variability in nematode distribution. Whilst members accepted that the variable distribution was a factor adding to the difficulty of interpreting the trials results it was also possible to interpret those data highlighted by the applicant in support of this argument to conclude that there is only a poor relationship between the damage recorded and nematode control. The fact that the standard treatment also delivered a more variable response than would be expected added to the difficulty of interpreting the trials. It could not be ruled out that the ‘fanging’ damage recorded might have been caused by some other factors, eg soil borne fungi. Whilst the applicant had provided some further information on Pythium, members noted that there are over 80 known species of Pythium and whilst the document addressed the species which are believed to be primarily responsible for cavity spot, (i.e P. violae & P. sulcatum), they did not necessarily consider other species that infect feeder roots of seedlings post-emergence to cause the disease known as carrot root dieback or ‘rusty root’ and which could potentially cause ‘fanging’ as the roots develop.
Post meeting note : the applicants clarified that such symptoms were very rarely noted in the trials. Measures are taken by the industry to avoid fungal pathology in seedlings by film coating the seed with a fungicide mixture. One of the fungicides, metalaxyl, is very active against Pythium. Members accepted the point but noted that it did not take account of potentially insensitive strains in the pathogen population.
6.3 Members also clarified that an approval can be granted if an ‘alternative’ product such as this gave a lower level of control than a more conventional chemical control. However it was important that the label advice given was very clear so that a grower would know what effect to expect.
6.4The applicant was then invited to join the meeting to present their case.
6.5 Ecospray introduced their case with an outline of the biology of free-living nematodes. Most species were small about 0.5-1.5mm in length, but Longidorus could reach 8mm in length. Whilst all free living nematodes have a highly aggregated distribution, each species has a different aggregation pattern, which differs from field to field. Trichodorus is known to track the water table and moves up and down the soil profile, travelling as much as 90cm over a matter of days. Free living nematodes feed by inserting a stylet and drawing out sap. This feeding method can introduce pathogens to a crop, and it can damage meristematic cells resulting in characteristic lesions or distortions. This may result in galling and/or secondary root growth. This damage has important impact on the quality of crops like carrots and parsnips, and the applicant showed slides illustrating the difference in quality of roots from the trials and also from commercial crops produced in 1996 treated with Temik, with symptoms characterised as nematode damage by Dr D Trudgill (SCRI). A late nematode attack can result in a loss of quality and thus value of the crop. Longidorus tends to feed along the roots whilst Trichodorus feeds at the root tip. (Post meeting note : the applicant clarified that both species can attack at the root tip). The applicant explained that a reasonable correlation with forking damage and Longidorus populations exists. This had been used by the applicants as the basis for interpretation of most of the field trial data. The illustrations showed evidence of multi-species attack.
6.6 The applicant then presented information on the variations in Longidorus distribution in 3 fields in 1996. Nematode numbers had been derived from 20 samples taken using a random W sampling technique. There were large differences in numbers recorded from one sample to the next. (Post meeting note : The applicant clarified that from one sample to the next, populations varied from zero to many times over the damage threshold used by EcoSpray. The applicant emphasised that this is extreme variance in population distribution and has profound implications when processing data and interpreting effects).This illustrated the difficulty of setting trials with certainty that there would be nematodes present in the plots, and this aggregated distribution was well known to create ‘noise’ in field trials. The applicant reminded members that they did not have complete freedom of choice where to set the trials as the trials had to fit into the farmer’s operations. They noted that the key factors of nematode biology that impacted on trials were the spatial variability and the conditions that facilitate attack. These vary in relation to crop growth stage.
6.7 Turning next to explain their GLIM statistical analysis, the applicant explained they had selected data where product dose responses were under investigation and had processed the results using linear modelling to give more degrees of freedom. They had grouped the efficacy data using five trials over three years on parsnips, and the applicant concluded that these showed there was no problem with treatment by trial interaction. The applicants presented data which they interpreted as showing that the 20kg/ha dose of Nemguard was significantly different in contrast to the other treatments. The applicants considered that there were data showing a dose response effect. (Post meeting note: The applicant stated their view that the absence of a treatment*trial interaction in the data sets is unequivocal evidence of a general consistency in product effect. The applicants’ belief was that if there was significant treatment by trial interaction, this would provide evidence of a general lack of product consistency). Angular transformation had been used to plot dose response. The applicant explained that it was clear that the variance in the control was more substantial than in the treated plots. (Post meeting note : The applicant commented that these data provide visual evidence of a treatment effect. The 20Kg/ha rate of Nemguard clearly restricted variance when compared to the untreated controls).
6.8 Following the most recent suggestion of the ACP, the applicant had also considered the Pf/Pi ratio. They noted that this approach had been developed for assessing work with cyst nematodes where very large numbers of egg masses are produced and they had not seen the approach used for free living nematodes before.
6.9 Finally the applicant concluded that having looked through their data and considered these together with the guidelines, they considered that their further statistical analysis had shown enough evidence of efficacy and that a dose response sufficient to support a full on-label approval was demonstrated.
6.10 The committee accepted that the Pf/Pi approach was not usually applied to data on free living nematodes, and that the spatial distribution of these nematodes did present particular problems. They noted the wealth of data presented at this meeting and submitted previously. They advised the applicant that the committee agreed that garlic juice concentrate has a nematicidal effect in the in vitro studies. They agreed that free living nematodes can cause damage to carrots and they agreed that the distribution of free living nematodes is very heterogeneous. The major difference between the committee and the applicant was in the interpretation of the field trials. Here the committee had concluded that Nemguard had shown an effect in some of the trials. However the committee considered that the effect was small and variable. The grower needs to have clear advice about use in their own situation. The committee asked the applicant what advice they would suggest.
6.11 In response the applicant drew attention to current best practice, and the need to identify that the nematode population was at the threshold determining the need for treatment. Information on the product was to use it at the rate which will exert an effect (20 kg/ha). Soil sampling will determine the nematode population and whether this is extreme. There is an upper limit past which consideration not to use the field because of excessive infestation should be given. Efficacy can be compromised by agronomic factors eg irrigation. Thus there should also be information provided explaining how to care for the field after sowing.
6.12 The committee commented that use of a threshold implies that there is a relationship between numbers of the pest and the damage seen, and that the product used has an effect on numbers. (Post meeting note: The applicant stated that determination of populations indicates the level of risk, but not the inevitability of damage, pointing out that a farmer will apply crop protection products in relation to perceived risk). The data submitted in support of this product show a good deal of variability, and they could also be used to determine that there is no real relationship between the nematode numbers and the damage recorded.
(Post meeting note: The applicant noted that this can be the case, but the survey in 1996 on 20 crops of carrots and parsnips reviewed by Dr D Trudgill and submitted in support of this application indicated that a relationship between populations and potential not inevitable damage was established).
6.13 The applicant replied that if about 30-40 nematodes (Longidorus) were present in a sample a grower may get damage. The vagaries on final damage levels are related to post-sowing conditions and spatial distribution of the nematodes.
6.14 The committee accepted that there are vagaries. However a farmer would be looking for robust advice. It seemed possible the small effect or low efficacy of nemguard may result in the product quickly being ‘swamped’ by nematode numbers.
6.15 The applicant responded that in their trials even an accepted ‘good’ nematicide showed an effect in only about 1 in 3 or 4 trials. The committee suggested that whilst this was off the point, it was possible to argue from this information that nematicides are not needed in this context, but the committee did accept that nematodes are a problem and control was required.
Post meeting note : The applicant argued that in their trials the approved products delivered variable results and from a statistical point of view no greater efficacy than Nemguard.
6.16 The applicant claimed that it was irrefutable that Nemguard reduces damage. What the farmer is interested in is the overall financial balance at the end of the year.
6.17 Members sought clarification from the applicant as to their level of confidence that the damage recorded was due to nematodes. It was clear that ‘fanging’ can be caused by other factors.
6.18 The applicant responded that Pythium was an obvious candidate for alternative causes. They had therefore looked at farm records considering cavity spot caused by Pythium in fields. The data supplied prior to the meeting indicated no correlation between Pythium damage (cavity spot) and root forking. The committee noted that the species causing cavity spot did not necessarily cause fanging but that other Pythium species are generally responsible for the disease referred to in the literature as carrot root dieback or ‘rusty root’. The applicant responded that other factors such as herbicide damage can also cause fanging. In that case they would expect to see a consistent pattern of damage across the trials, but there was nothing in the trial statistics to suggest this. Most seeds are treated with fungicides which should protect the seedlings during the period of growth vulnerable to nematode attack. They therefore concluded that the effects seen were due to nematodes. In addition they noted that the standard treatment (an approved nematicide) did have an effect in controlling the symptoms.
6.19 Having confirmed that the applicant did not want to ask any further questions, the Chairman thanked them for their presentation, and they departed.
6.20 The committee then considered the presentation. They concluded that the information presented did not take them further. The Chairman clarified that a new statistical approach had been used to try to demonstrate an effect. The committee concluded that if there is an effect it is very small and inconsistent.
6.21 Members agreed that the Pf/Pi approach is not usually used for free living nematodes. They had suggested intensive sampling for nematodes before during and after treatment which they accepted would be difficult and expensive. The less intensive approaches tried thus far had yielded inconclusive results. Members noted that the very complex biology of the pest demanded careful statistical planning in preparing the trials. The committee noted that if an effect could be shown it would be good to be able to offer a variety of products to the farmer. Members noted that the bottom line for the farmer was whether there was a cost benefit to this treatment. It was known that the standard treatments did yield such a benefit. Bearing in mind the difficulty of the proposed trials, members considered whether there was a possibility of demonstrating an effect. They therefore considered whether data on previously approved nematicides indicated that this was a possibility. PSD confirmed that they had looked back at the data supporting two previously approved nematicides. In each case there was a clear correlation between use and reduced damage. Whilst a clear effect had not been seen in all trials there was a clear effect in most of the trials – which was not the case with the data on Nemguard. As such, in most previous cases it had not been necessary to seek the detailed information of nematode numbers now proposed for Nemguard.
6.22 Members agreed to write to the company, noting that they had concluded there was no reason to change the previous advice. In addition they would re-visit the advice on trials sent the previous week without prejudice to this discussion. Members noted that as they had accepted all other areas of the risk assessment for this product there was no reason to prevent the treated produce resulting from these trials from entering the food chain.
7. Setting unsprayed buffer zones for arable horizontal boom applications in the UK ACP 13 (331/2008)
7.1 Members heard that risk assessment for surface water currently considered spray drift contamination by calculating the estimated concentration of pesticide reaching surface water based on a combination of distance and spray drift deposition data. A recent meeting of experts had concluded that there have been changes in application methods which led them to consider that the current model might need to be updated. In response PSD is undertaking some further work and has proposed seeking the views of UK stakeholders and other member states about the need to update the spray drift data set currently used across the EU for surface water risk assessment.
7.2 Once the estimated concentration reaching surface water has been determined an assessment of the toxicity: exposure ratio ( TER) is made and if necessary risk management is required to ensure that the risk to aquatic organisms is acceptable. At present risk management strategies are a matter for each European member state to determine. The UK approach has been to have a basic no spray buffer zone of 5m for arable crops and to develop the Local Environmental Risk Assessment for Pesticides ( LERAP) scheme for subsequent on site adjustments, taking account of other risk mitigation factors such as reduced application rate or use of low drift nozzles. Other European member states have developed a range of alternative risk mitigation approaches including the use of buffer zones rather larger than 5m. These different approaches have led to some significantly different decisions on approvals between member states, and PSD also wished to consider the possibilities of introducing a risk management scheme to the UK that was more compatible with the rest of the EU with the overall aim of creating a ‘level playing field’ for crop protection in the EU. Members confirmed that it was important to try and ensure UK approaches were kept in line with developments elsewhere in Europe where possible. In this context they asked PSD what steps could be taken to consider such a level playing field during the current re-registration process. PSD agreed to take what measures they could to ensure the UK industry is not disadvantaged relative to other EU Member states.
7.3 Members agreed that there were thus two parts to the proposals for consultation. It was important to confirm first the technical aspects relating to the spray drift data to be used in risk evaluation, and subsequently to consider possible changes to risk management strategies.
7.4 Members noted that the data emerging on spray drift were compelling and agreed there was a need to reconsider spray drift data that were relevant to modern application practices.
7.5 Members had previously noted that factors such as boom height had a significant impact of drift and agreed that it was reasonable to assume a boom height of about 0.7m above a growing crop. However they also noted that booms might need to be more than 0.5m above bare soil to prevent damage being caused as the boom moved during the application. Members commented that enforceability would be an important factor in development of any new scheme and PSD confirmed that the introduction of LERAPs had in fact improved enforceability by requiring records to be kept which were now inspected as a part of the cross compliance inspections.
7.6 The committee observed that a buffer zone was not necessarily the only suitable option for risk management. Some other member states used engineering controls such as particular nozzles or spray boom set-ups, and PSD responded that this was essentially the third part of the consultation – namely whether engineering controls were suitable for inclusion as a condition of authorisation to manage risk.
7.7 Members added that the spray operator was the other key factor affecting spray drift and both the requirement for training and the National Register of Spray Operators had led to improvements in the standard of spraying. From a practical point of view it would also be helpful to users if various government schemes could be linked up eg in seeking overall protection for water quality. PSD noted that whilst this would be good for users, because such schemes tend to change with time they did not form an ideal basis for regulation.
7.8 Overall members confirmed that it was appropriate to consult stakeholders and other member states as proposed and they noted that conclusions on spray drift would also be relevant to other areas of risk assessment.
8.Consultation on the repeal of the Farm and Garden Chemicals Act ACP 8 (331/2008)
8.1 Members agreed a draft response supporting the proposed repeal of the Farm and Garden Chemicals Act.
9. Pesticide Usage Surveys, information requirements ACP 16 (331/2008)
9.1 Prof Brown declared a personal non-specific interest in that he spent some of his time working for the FERA who also run the pesticides usage survey for England and Wales. Dr Griffiths also declared a personal specific interest as the Scottish survey group formed a part of his official responsibilities.
9.2 Members heard that as part of the preparations for implementation of the EU pesticide statistics regulation, PSD was seeking further information on the use made of pesticides usage data and of any gaps in the information currently available.
9.3 Members confirmed the importance and usefulness of the data collected in the pesticides usage survey. Members noted that there are more data available in the survey databases than were included in the published reports.
9.4 Members suggested some aspects of information that would be helpful. For example it would be useful to have more information on the target pest being treated, on the proportion of holdings actually visited and the representativeness of the sample. Also the frequency of the surveys might be considered as four year intervals made determining trends rather difficult. PSD explained that the surveys followed a standard methodology using stratified random sampling. About 4% of the total arable area of cropping was included in survey visits but up to about 30% for some smaller crops where there was greater inherent variability in the pesticides used. They noted that the target pest is rarely noted in farmer records and the information available was largely down to the skill of the interviewer in obtaining information. Indeed farmers often treat their crops based on advice and thus might not recall the details of target pests. PSD agreed that survey intervals greater than 2 years made trend analysis difficult, but noted that it was also important to keep costs under control.
9.5 Members suggested that some geographical basis for the usage information would be useful in seeking to compare adverse effects data with likely patterns of use in the area, and correlation with other data sets on land cover/use would also be useful.
9.6 PSD confirmed that the stratified samples were taken to County level so some more local information should be available.
9.7 Members noted that the PSD had recently commissioned a study on usage in the amenity sector and that this was not routinely covered by the usage surveys, and would provide useful information. Members noted that local authorities and other amenity users were keen to consider the environmental impact of their activities and thus might well be more willing to provide usage information than perhaps had been the case in the past
9.8 The Committee also noted written comments confirming the importance of these data. Information about the pattern of pesticide usage was identified as essential to the understanding of the overall pattern of potential aggregate and cumulative exposure to pesticides, both amongst those who may be exposed at the time the pesticides are applied and from food consumption. This information had been used during a project, funded by the Food Standards Agency, to estimate the population intake of pesticides from all potential pathways.
9.9 Other information that would be helpful to obtain as part of these data collection exercises was information that was relevant to human risk assessments, e.g. some information about the number of people and duration of work for those involved in the application and in post application work, plus some information about the number of people living in the proximity of the field for which information is collected. Collecting this type of information at the time of the survey would probably add little to the costs but would substantially increase our understanding of the potential for exposure.
9.10 Finally PSD agreed that it would be helpful if the ACP responded to their enquiry by forwarding this record rather than writing a separate letter.
10. ACP Openness Survey Results ACP 7 (331/2008)
10.1 Members noted the low response rate for this survey, but welcomed the generally positive views expressed. They agreed that it appeared that the majority of responses were from stakeholders in the pesticide industry.
10.2 The Committee agreed to take note of the results, and repeat the survey at the time of the next ACP Open Meeting in an attempt to obtain a broader response from the public and other stakeholders.
11. Report from the Medical and Toxicology Panel
11.1 Members heard a short report from the Chairman of the medical and toxicology panel of the previous day’s meeting.
11.2 The panel had considered some recent Defra funded research on conjugated residue behaviour.
11.3 The consideration of biological exposure studies in the published literature would be forwarded to the September meeting of the ACP for consideration.
11.4 The panel discussed the use of the Bonferroni or other corrections in statistical analysis and concluded that where such corrections were used both corrected and uncorrected analyses should be presented. It was possible that this might cause some problems for industry due to their use of particular statistical packages, but it should be possible to overcome these with some minor modifications.
11.5 The panel had considered some recent published developmental neurotoxicity data on chlorpyrifos. The panel recognised that chlorpyrifos can cause a range of effects in toxicology tests and the issue for regulation was identification of the most sensitive end point to select as the basis for reference doses. The panel had heard that a USEPA advisory panel was due to consider this issue in July, so they agreed to forward the medical and toxicology panel papers to that group to include in their consideration.
11.6 Finally, the panel had agreed to ask PSD to investigate a possible study of the association of asthma with exposure to pesticides. This might take the form of a systematic literature review.
12. Date of the next meeting:
12.1 ACP 333 on Tuesday September 16th 2008, commencing 11am, at the Monk Bar Hotel, York. ACP 332 due to be held on 1st July has been cancelled.
13.Any other business
13.1.a) Proposed 2009 Meeting Dates ACP 14 (331/2008)
13.1.1. Members were asked to consider the meeting dates suggested for 2009. They commented that the June/July date suggested could perhaps be a little later without running into holiday periods and this would reduce the gap between meetings over the summer.
13.2 b) Update on negotiations on the replacement for 91/414/EEC
13.2.1 PSD advised members that the tabled paper ‘Assessment of the impact on crop protection in the UK of the ‘cut-off criteria’ and substitution provisions in the proposed regulation of the European Parliament and of the Council concerning the placing of plant protection products in the market’ had been published on the PSD website on Friday 9th May [link]. Members heard that various different estimates of the impact of the proposed regulation had been produced by a range of interest groups. Whilst it was not certain what the actual impact would be, not least because some of the proposals were still unclear, PSD had outlined clearly in this paper the basis for their estimates and thus the paper outlined what might happen. Particular areas of uncertainty were that the criteria were not yet well defined, particularly the criteria for endocrine disruption, and of course the regulation is still in negotiation meaning that the final outcome is still uncertain. However under amendments put forward by the European Parliament in relation to cut off criteria and allowing just a single five year approval for ‘candidates for substitution’, the PSD paper concluded that only around 10% of pesticides currently approved for use would remain.
13.2.2 The Committee responded that if the projections were true this would have very serious implications for European agriculture. Members commented that they had consistently advised that it was not appropriate to try to regulate pesticides based on hazard criteria, and that risk assessment should remain the approach used.
13.2.3 Members noted that it was very important to keep as many options available as possible, particularly in the light of developing global changes. It seemed likely that Western Europe was likely to need to produce an even greater proportion of the global food supply as this was an area of the world where climate changes were likely to have a lower impact on agriculture. Members noted their concern that approval of pesticides was becoming more political and apparently disregarding the science.
13.3 c) Correspondence with the Chair of the HSE
13.3.1 Members remained concerned that the most recent reply from the Chair of the new HSE did not really do justice to the importance of post approval monitoring. Members noted that the HSE is currently reviewing its overall strategy and its science strategy and members agreed to ensure that post approval monitoring remained on HSE ’s new agenda.
J G Ayres