Last updated on 25 March 2003

Mixtures of pesticides research programme

Details of the Agency-funded research programme on mixtures of pesticides.

Introduction

This programme responds to the recommendations of the Committee on Toxicity (COT) for research related to Risk Assessment of Mixtures of Pesticides and Similar Substances.

Aims

This programme takes forward the research recommended by the Committee on Toxicity (COT) Working Group on Risk Assessment of Mixtures of Pesticides and Similar Substances. The aim is to provide the tools needed to study potential interactions between mixtures of different pesticides and related substances, and to underpin risk assessment of such combined exposures.

This programme supports the Agency's Strategic Plan in the following areas:

  • ensure that chemicals present in food do not compromise food safety
  • ensure that procedures for assessing new and existing products are based on the best available science
  • safety assessment processes that protect consumers, are robust and are applied rigorously

The COT report has addressed consumer concerns about possible implications of interactions between components of mixtures of chemicals (the 'cocktail effect'). Implementing the COT research recommendations will contribute to two of the Agency's core aims and values:

  • to protect consumers through improved food safety and standards
  • to measurably improve public confidence in the national food safety and standards arrangements

Abstract

The COT report concluded that there are a number of ways in which exposure to pesticide, veterinary and other chemical residues in food might theoretically result in unexpected toxicity. There is evidence for limited exposure of humans to multiple residues at low levels, but no substantiated accounts of adverse reactions to such exposures, except under laboratory conditions. The COT concluded that the nature and extent of combined exposure, together with the likelihood of any adverse effects, which might result, should be evaluated when carrying out risk assessment. However, we do not currently have the tools that would allow us to investigate whether interactions may occur at the low levels of residues to which consumers are exposed, or sufficient scientific understanding of the toxicology of mixtures to allow such risk assessment. Furthermore, the COT noted concern that certain groups in the population, notably pregnant women and young children may be at higher risk from possible interactions than other adults.

This research programme therefore aims to develop and validate these tools. Biomarkers of exposure will allow an assessment of the total amounts of mixtures of pesticides and other residues in the human body. Biomarkers of effect would support early detection of possible health effects arising from such exposure. Investigation of possible variability in human response will help to determine whether subgroups, such as children or older people, may be at greater risk of harmful effects than the general population.

A comprehensive risk assessment requires detailed information on exposure from all sources as well as on potential health effects. Further aims of this programme will be to collate information on all pathways of exposure to pesticides and veterinary medicines, and to assess whether controls on exposure within the EU would be sufficient to significantly decrease our total exposure to these residues.

On completion, the programme should have:

  • Established robust tools to support investigation of whether dietary exposure to mixtures of different pesticides and similar substances may have implications for human health.
  • Increased scientific understanding of the nature of combined actions of pesticides and similar substances, in support of improved risk assessment and measures related to regulatory approval.
  • Increased scientific understanding of the variability in response of different subgroups, such as children and older people, to combined actions of pesticides and similar substances.
  • Improved understanding of the sources of human exposure to pesticides and similar substances, which will provide a robust scientific basis for future regulatory measures.

Rationale

This research programme supports policy objectives relating to:

  • ensuring consumer interests are taken into account in the safety assessments of pesticides and veterinary medicines
  • obtaining the best scientific advice on safety of pesticides and veterinary medicines in food
  • safety assessment processes that protect consumers, are robust and are applied rigorously

The research responds to consumer concerns on the 'cocktail effect' and will provide the background information needed to underpin improved risk assessment for pesticides and veterinary medicines.

It will ensure that risk assessment for pesticides and veterinary medicines is based upon the best available methodology. The approaches developed in this programme will also be of relevance to risk assessment for mixtures of other categories of food chemical.

The scientific objectives of the programme are:

  • The 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.
  • The development of markers to enable early and reliable detection of systemic responses and health effects arising from such exposures (biomarkers of effect).
  • The characterisation of possible variability in human responses to mixtures of residues.
  • Experimental research to characterise the nature and dose-response relationships for combined actions of chemicals when administered together.
  • The obtaining of robust data on all pathways of exposure to pesticides and veterinary medicines and on sources of variation in exposure.
  • The assessment of the impact of implementation of the recommendations within the EU alone taking account of the exposure to products that will be imported from outside the EU.
  • The effects of the nature of processing and preparation on the bioavailability and chemical nature of residues.

Contact for further information

Name: Diane Benford

Tel: 020 7276 8510

Email: diane.benford@foodstandards.gsi.gov.uk

List of projects

  1. Establishment of common mechanism groups for pesticides and similar substances: A pilot study to establish resource requirements

    In 2002, the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) published a report from a COT Working Group for the Risk Assessment of Mixtures of Pesticides and Veterinary Medicines (WiGRAMP).

  2. Project details: Mixtures of pesticides research programme T10

    Information about Agency-funded research projects.