Progress Report by WHO on the Development of Databases for Acute Exposure Assessment (Agenda Item 5a)
Review of the Procedure Dealing with Chronic Dietary Exposure Concern (Agenda Item 5b)
Risk Analysis Principles and Methodologies so far Applied in the Work of the Committee (Agenda Item 5c)
Report on the Revision of Regional Diets and Information on Processing (Agenda Item 5d)
28. The Representative of WHO reported on the calculation of the International Estimated Short-Term Intakes (IESTI) prepared by the 2000 JMPR (Section 3.2 and Annex 4) and noted that the JMPR could not confirm that the IESTIs would be below the acute RfDs for chlormequat in pears; dinocap in grapes; and parathion in barley and apples. It was also noted that the 2000 JMPR included several corrections to the IESTI calculations performed by the 1999 JMPR (Annex IV).
29. In response to Circular Letter CL 2000/27-PR, Part 4 (A), information was provided by the United Kingdom and the United States on national approaches for estimating short-term intakes, which used deterministic and probabilistic approaches, respectively. The EU and Australia indicated that their approaches applied similar principles to those used by JMPR. South Africa reported that a total diet study was underway and that this data could be used as the basis for estimating short-term intake.
30. In regard to the request for additional data[5] to further develop the large portion databases 97.5 percentile food consumption (eaters only) data was received from Australia and New Zealand but were not expressed on a body weight basis. In addition, Sweden provided data on median weights and edible portion of a number of commodities.
31. Some delegations and the Observer from CI expressed the view that the existence of different procedures in member countries for acute exposure assessment would create problems and that approaches should be harmonized at the international level.
32. The Delegation of the Netherlands informed the Committee that guidance was under development at the national level on the criteria and procedures for the establishment of acute reference doses, and the Committee invited the Delegation to communicate these guidelines to JMPR for consideration by its next meeting in 2001.
33. Other member countries and international organizations were also invited to submit the result of their studies to JMPR to facilitate further consideration of this issue. This was especially important since current toxicological databases were not designed for establishing acute reference doses, as indicated in the JMPR Report (section 2.10).
34. The WHO JMPR Joint Secretary indicated that the role of JMPR was not to consider individual national acute RfDs but only develop criteria for their establishment at the international level; for that purpose, it was necessary to receive guidance from member countries on the methodology applied at the national level.
35. The Observer from the GCPF indicated that a project on variability of residues following single unit analysis had been conducted on the basis of supervised field trials and that the statistical analysis of the data was underway, and that it would be submitted to JMPR.
36. The Committee recalled that the last session had considered how to proceed when the IEDI indicated that the ADI might be exceeded in one or more regional diets; that no consensus had been reached and the Committee had agreed that the Delegation of Australia would redraft its discussion paper for further consideration.
37. The Delegation of Australia highlighted the problems caused by the IEDI calculations as they might result in an overestimate of dietary intake, even when national dietary calculations demonstrated that the ADI would not be exceeded. The Delegation presented the recommendations put forward in the document to address this problem: continued development of dietary exposure calculations at the international level to provide realistic estimates; developing criteria for the use of national total diet studies; convening an expert consultation on this subject; encouraging countries to submit relevant data for dietary intake calculations; limiting the emphasis on international dietary intake while considering MRLs. It was also proposed to consider the establishment of MRLs even when the ADI was exceeded in one of the regional diets.
38. Several delegations supported the continued development of dietary exposure calculations at the international level, in order to provide a more realistic estimate of exposure and pointed out that member countries should provide additional data to improve the current process.
39. The Delegation of the United States supported the improvement of the chronic intake assessment since current practice resulted in overestimates, and indicated that MRLs might be finalized when the ADI was exceeded only in one regional diet. The Observer from GCPF expressed the view that the adoption of such MRLs would not result in a lower level of protection as IEDI calculations were too conservative and created artificial problems as ADI calculations were very conservative and action taken would be addressing an artificial problem.
40. Several delegations and the Observer from Consumers International expressed their objection to a shift in emphasis from international to national dietary intake studies and to the adoption of MRLs when the ADI was exceeded in any regional diet. They stressed that it would not be consistent with Codex objectives since standards for the protection of consumers’ health should be developed on a worldwide basis. Some delegations pointed out that this would create specific problems for developing countries because they relied on Codex recommendations when they could not carry out their own risk analysis.
41. Some delegations supported the proposal to convene an FAO/WHO expert consultation on dietary intake estimation to address this complex issue. Other delegations felt that it was difficult to give a clear mandate to such a consultation at this stage and that not enough relevant data appeared to be available for that purpose.
42. The Committee agreed that there was a need for improvement in international dietary estimates and that work should proceed in this area, and encouraged countries to generate relevant data in order to refine dietary intake calculations, as indicated in the JMPR report.
43. The Committee recognized that current procedures should be retained for the time being and reasserted its earlier decision that no MRL should be advanced to Step 8 when the ADI was exceeded in one or more of the regional diets.
44. The Chairman introduced the document prepared at the request of the last session of the Committee in order to consider the application of risk analysis principles and methodologies to MRL setting for pesticide residues.
45. The Chairman pointed out that considerable progress had been achieved concerning chronic intake, especially through the revision of the WHO Guidelines for Predicting Dietary Intake of Pesticide Residues (1997), and recalled the major issues considered by the Committee: clear distinction should be made between national and international approaches; MRLs could be finalized when the ADI was not exceeded in any of the regional diets; the current procedure had been maintained as there was no consensus on a review of dietary intakes calculations at the international level (see para 43). The Chairman also referred to recent developments as regards acute dietary intake, including the establishment of acute reference doses in JMPR and the consideration of acute toxicity as one of the criteria for MRL setting. However, this remained a difficult issue and would require further consideration, as appeared from earlier discussion (see Agenda Item 5a).
46. The Committee expressed its appreciation to the Chairman for this comprehensive document summarizing the integration of risk analysis in the work of the Committee. Several delegations, the Representative of WHO and the Observer from the EC supported the conclusions of the document and indicated that no further action was needed in the Committee.
47. The Delegation of Spain pointed out that further consideration should be given to variability factors, as it appeared from the JMPR Report (2000) that they were very high in some cases, especially for soil treatment, and this might lead to an overly conservative approach. The Representative of FAO/IAEA recalled that JMPR calculations were based on comprehensive residue data and that the variability factors used in IESTI accurately reflected the residues found in a wide range of products.
48. The Observer from Consumers International indicated that a comprehensive document on risk analysis was under preparation in the Committee on Residues of Veterinary Drugs in Foods, and proposed to follow a similar approach for pesticide residues. In particular, the Observer stressed the importance of addressing risk assessment policy, the relativenes between risk assessment and risk management, the use of other legitimate factors by both CCPR and JMPR and risk communication.
49. The Delegation of New Zealand supported this view and stressed the importance of defining risk assessment policy in the Committee, and addressing risk communication, especially as it was important to inform other Codex Committees of the approach taken by the CCPR in the establishment of EMRLs.
50. The Chairman noted that although the risk analysis procedures followed in MRL setting were not currently presented in a single document, they were reflected in several guidelines or related texts used by JMPR and CCPR, such as the FAO Manual on Data Submission and Evaluation of Pesticide Residues Data for the Estimation of Maximum Residue Levels in Food and Feed, the WHO Guidelines for Predicting Dietary Intake of Pesticide Residues, the agreed CCPR policy on EMRL setting, and the periodic review procedure.
51. The Committee noted that the Committee on General Principles was currently considering Proposed Draft Working Principles for Risk Analysis and that the 24th Session of the Commission would consider the reports from relevant Codex Committees on the integration of risk analysis in their decisions. The Committee agreed that there was no need to develop an additional document on risk analysis at this stage and noted that future action would depend on the recommendations of the Commission in this area.
Regional Diets
Information on Processing
52. The Committee at its last Session requested clarification on the possible impact of the revision of GEMS/Food Regional Diets on dietary exposure estimates undertaken by JMPR (ALINORM 01/24, para 38). The WHO Representative presented calculations of the TMDIs for a hypothetical pesticide using the existing 5 GEMS/Food Regional Diets and the 13 proposed GEMS/Food Consumption Cluster Diets. The results suggested that, on average, the proposed diets would slightly increase the exposure estimates, but that the range of values would increase. For the existing European-type diet, the 5 Consumption Cluster Diets that would replace it would result, in the worst case, in an increase of about 60% in the estimated exposure compared to the current diet.
53. The WHO Representative noted that the increase in exposure was expected because the current diets tend to average consumption of commodities among countries which have very different consumption patterns. For example, the consumption of maize in the existing African Region included countries which are both high and low consumers of maize. Consequently, the consumption of maize for that region is currently underestimated. Therefore, the Consumption Cluster Diets, when completed, would represent a more accurate description of the dietary patterns of Member countries. The full development of the diets to include about 250 commodities for which Codex MRLs exist or are proposed as well as certain processed commodities may take up to three years because consumption of many foods will need to be estimated. It was noted that the CCFAC and the JECFA are also using the existing 5 GEMS/Food Regional Diets in estimating exposure to contaminants and that JECFA welcomed the revision of the diets to more accurately estimate exposure.
54. The Committee also requested WHO to provide an estimate of the total consumption of food in order to assess potential differences among Cluster Diets. The estimated total food consumption ranged from 1156 g per person per day to 2337 g per person per day. The lower value was probably underestimated because food produced by subsistence farmers is not included in the FAO Food Balance Sheets.
55. In reply to some questions the Representative of WHO recalled that the definition of exposure assessment referred to exposure from all sources and confirmed that veterinary use was taken into account in the calculations of dietary intake. This appeared for example in the case of the IEDI calculations for thiabendazole included in Annex 3 of the 2000 JMPR report.
56. The Committee generally supported the development of the 13 revised regional diets and noted that further refinement of the diets would be required, including examples of calculation MRLs for fruits and vegetables, before recommending their use for the purposes of JMPR. The Committee agreed that it should be informed about significant further progress made in the framework of GEMS/Food on the finalization of the regional diets.
57. The WHO Representative also reported that in response to CL2000/27-PR no additional information had been received from Governments on national food processing practices. It was noted that only Thailand had completed the processing questionnaire.
58. In reviewing the questionnaire (Section 2.2), the 2000 JMPR welcomed the use of the questionnaire to fill gaps in knowledge about typical methods of processing of raw agricultural commodities. In particular, information on significant differences in processing techniques from one region to another would be useful. The JMPR noted that information on important processed foods, such as various fruit juices, barley beer, maize meal and bran of rye and wheat was currently not available for use in dietary risk assessment.
59. The Committee was informed that GEMS/Food was reconsidering the questionnaire to focus on specific processed commodities of importance to exposure assessment. This would take into account information made available to Member countries based on actual national and regional requirements for data on the fate of pesticides during processing.
60. Some delegations expressed the view that the purpose of collecting processing information was not entirely clear, especially as it appeared that only a small portion of the ADI was used with current MRLs. Other delegations supported the development of such studies as it was important to demonstrate that the MRLs were safe on a worldwide basis.
61. The Committee recognized that no further progress could be made at this stage in CCPR as no additional data had been submitted on processing and noted that this would be considered further in the framework of GEMS/Food on the basis of the processing studies available at the regional and national level.
62. The Committee agreed to discontinue the collection of information through the questionnaire. However it recognized the importance of collection information by GEMS FOOD about processing studies currently required by national governments.
