Food safety

Joint FAO/WHO consultation on food consumption and exposure assessment to chemicals in food. Geneva, Switzerland, 10-14 February 1997

Executive Summary of a Consultation Jointly Convened by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO).

A Joint FAO/WHO Consultation on Food Consumption and Exposure Assessment of Chemicals was held in Geneva, Switzerland, 10-14 February 1997. This Consultation is the fourth in a series of consultations concerning risk analysis sponsored by FAO and WHO.

The Consultation recommended an expansion of the five regional diets presently used by the Global Environmental Monitoring System - Food Contamination Monitoring and Management System (GEMS/Food) for dietary exposure assessments of pesticide residues at the international level and agreed on a method for establishing new regional diets based on a cluster analysis of aggregated FAO food balance sheet data and geographic considerations. The preliminary cluster analysis resulted in 13 unique regional diets. It is expected that the final analysis of detailed FAO data will result in a similar number of regional diets. FAO/WHO will undertake this work and the final analysis is expected during the 1998 calendar year. It was also recommended that the food balance sheet data used should be based on a 5-year average, that the frequency of updating this information should be on a cycle of ten years or less, and that data from emerging countries and countries undergoing dramatic economic change should be updated as information becomes available. The resulting regional diets should be made available to all countries in an open and transparent manner.

The Consultation considered various issues related to acute dietary exposure assessments. The Consultation developed a proposed methodology (procedure) for performing these acute dietary exposure assessments and recommended that it be presented for consideration by the Codex committees. This procedure, although discussed in the context of pesticide residues, is considered applicable to all food chemicals where an acute reference dose (acute RfD) has been established. The procedure, when applied to pesticides, veterinary drugs, and contaminants will require the establishment of a large portion weight data base. GEMS/Food will establish a large portion weight data base which will contain entries for each food commodity. Ideally, this information should be obtained from individual country data within each region identified above. The data base should contain large portion weight information (97.5 percentile) for those consuming the food in the target groups, for example, children less than or equal to six years of age, and the overall population. GEMS/Food will also develop a unit commodity weight data base for certain food commodities. This data base will be maintained for each region and will initially be constructed from national/regional nutrient composition tables. Member States are invited (expected) to submit information on large portion weights to GEMS/Food during 1998.

The Consultation noted that, in principle, the determination of potential exposures is the same across all food chemicals. The Consultation agreed that the principles outlined in this report for pesticides are applicable to dietary exposure assessment for all food chemicals. The Consultation recognized, however, that the specific application of these procedures to different food chemicals may differ. The focus of the dietary exposure assessments must be on estimating equivalent levels of consumer protection. Consequently, the dietary exposure assessment must use sound and transparent scientific methods such that the provisions of the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) are satisfied.

The Consultation made recommendations to ensure that the overall approach to international dietary exposure assessments is rational, consistent across different Codex committees, and uses the best available food consumption or residue data with the most appropriate method for combining the two data sets. Therefore, the Consultation recommended that the terminology from this report for dietary exposure assessment be used in all Codex Committees to standardize the dietary exposure assessment descriptions.

At the international level, dietary exposure assessments have an important function to screen food chemical(s) intakes and identify those chemicals with a potential public health and safety concern. The Consultation noted that while international dietary exposure assessments are useful for those countries with no capacity to undertake national dietary exposure assessments, such exposure assessments cannot be used to estimate actual dietary exposures to food chemicals in individual countries or for specific population subgroups.

The Consultation made recommendations to promote consistent and transparent approaches in conducting dietary exposure assessments and recognized that the process of dietary exposure assessment and risk management is an iterative process that requires good communication between the risk assessor and the risk manager. This communication should provide sufficiently detailed explanations from risk managers on risk assessment policy, and from risk assessors on the quality and quantity of data supporting exposure assessment. Additional guidance on the form and presentation of this information may be needed to be developed.

The Consultation recognized the special requirements of developing countries for firstly learning the procedures proposed for dietary exposure assessment, and secondly applying that knowledge utilizing the available resources and personnel. The Consultation made specific recommendations regarding the need for assistance at the international level, and for better integration of developing country personnel into the Codex standard setting processes.