COT Pesticide Report: Executive Summary

Over 350 active substances are approved as pesticides in the United Kingdom (UK), and other compounds may be present in food imported from other EU states and elsewhere. Many pesticides and veterinary medicines contain only one active ingredient. However, some may contain more than one active ingredient and individual foods (either crops or foods of animal origin) may have been treated with a number of pesticides or veterinary medicines.

Furthermore, in any one meal, individuals may eat a variety of foods that may have been treated with a number of different pesticides or veterinary medicines. This means that our diet may contain residues of a number of different pesticides and veterinary medicines, often described as a cocktail.

Consumers and interested organisations have been concerned for some time about the possible implications of interactions between the components of mixtures of chemicals dubbed the 'cocktail effect'. The Food Standards Agency had also carried out a telephone consultation of consumer groups that highlighted concern about the cocktail effect, particularly when children could be consuming foods possibly containing multiple residues of pesticides and veterinary medicines.

Consequently, shortly after it was established, the Food Standards Agency announced its intention to set up a group of independent experts from the Committee on the Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) to consider the cocktail effect.

Work carried out by the Environmental Protection Agency (EPA) in the United States has produced draft guidelines outlining its approach to the risk assessment of combinations of pesticides, referred to as a cumulative risk assessment. Very little work had been carried out at a national (UK), European or international level in this area.

The Working Group began in December 2000 with a trawl of the existing scientific literature in order to establish a base of information from which to start. This was developed over time, as the issues on which the Group needed to focus became clearer. The Group also recognised from the outset the need to appreciate the concerns held by stakeholders, so that these could be addressed in the report. An open meeting was held in April 2001 at the Food Standards Agency.

Presentations were made by invited experts and interested organisations (Friends of the Earth and the Crop Protection Association). Individuals and others - mainly scientific experts - were also able to present information directly to the Group, for the Group to discuss in subsequent meetings.

In total, nine meetings of the Group were held (including the open meeting) prior to the publication of a draft report for public consideration. There was then a six-week consultation period in which written comments were invited and a further open consultation meeting was held in Norwich to enable interested individuals and organisations to comments on the draft report.

The main conclusions of the COT Working Group are:

• The probability of any health hazard due to exposure to mixtures of chemicals, each present at a low level (as is the case in food), is likely to be small
• Good estimates of exposure to groups of chemicals are not available for exposure through routes other than food
• Children and pregnant or nursing women are unlikely to be more vulnerable to the effects of mixtures than the general population
• The body of evidence is nonetheless limited and it is possible that some interactions are not readily predictable.

The Committee made recommendations in four areas:

Regulatory

• Changes to the approval system so that the bodies authorising pesticides and veterinary medicines are required to consider all sources of exposure (rec 11.1)
• A framework should be generated to decide when to carry out combined risk assessments of exposure to more than one pesticide and/or veterinary medicine (rec 11.2)
• Certain toxicological approaches should be taken depending on the type of action and/or interaction of chemicals when carrying out risk assessments of potential combined exposure (rec 11.3)
• Approval of pesticides and veterinary medicines should include more formal analysis and possible experimental investigation into the potential for combined toxic action due to the cocktail effect (rec 11.4)
• Analysis of all sources of exposure and concurrent exposure to more than one pesticide will require changes in the methods used for risk assessment (rec 11.5).

Implementation of these recommendations will require the use of available but presently unused methods, which are in turn contingent on data.

Surveillance

• Dietary and food consumption surveys in the UK should continue to cover all social, age and ethnic groups within the population (rec 11.6)
• Aggregate exposure assessment will require robust data on all pathways of exposure and sources of variation in exposure (rec 11.7)
• Residue surveillance programmes should be modified in the light of the need for representative data for probabilistic exposure assessment (rec 11.8)

There is a need for additional data from surveillance programmes of residues and from other sources

Research
New research has been recommended to look at:

• Development of methods to provide cost effective biomarkers or other robust indicators of population exposure and body burdens of mixtures of pesticides and relevant veterinary residues (rec 11.9)
• Development of markers to enable early and reliable detection of systemic responses and possible health effects from exposure to pesticides (rec 11.10)
• Characterisation of the possible variability in human responses to mixtures of residues (rec 11.11)
• Experimental research to characterise the nature and dose relationships for combined actions (rec 11.12)

Public Information

• The creation of a central and accessible repository of information about all forms of exposure to pesticides and similar substances (rec 11.13)
• Review of the extent and adequacy of information available to the domestic user of pesticides and veterinary medicines (rec 11.14)

The Report made a number of recommendations and a large number of these have called for further research. The Food Standards Agency has responded to this at an early stage by establishing an Action Group comprising of officials from the Agency, Pesticides Safety Directorate, Veterinary Medicines Directorate, and Health and Safety Executive to prepare a plan of action for the implementation of the Report’s recommendations.

The Action Plan is being finalised and is expected to be published shortly. The Agency is also advertising for a Programme Co-ordinator to oversee the research programme.