THE ROLE OF TOXICOLOGY IN THE EVALUATION OF NEW AGROCHEMICALS

The use of agrochemicals like crop protecting agents, veterinary disin fectants, and wood preservatives may result in (un)intentional exposur e of the environment, animals and man. This paper deals with current t esting strategies to assess the potential health risks for humans expo sed to these chemicals during production or application or via consump tion of foods containing pesticide residues. Principles and procedures for safety assessment of pesticide residues in food as developed by W HO/FAO are described. Different types of toxicity studies in mammalian test animal species are discussed and a strategy is outlined in order to characterize the toxicity profile of a compound and the relationsh ip between applied doses and adverse effects. Safety testing of agroch emicals should be carried out in relation to its intended use, and in particular attention will be paid to toxicity testing of residues of p esticides in food. Extrapolation of results from animal studies to hum ans and the use of safety factors is discussed. Besides the use of ani mal protocol studies for safety testing of agrochemicals, the potentia l use of in-vitro models derived from organs and tissues of animals is discussed. Data on the in-vitro metabolism of thiabendazole, aldicarb and alachlor are discussed in order to demonstrate that such data may complement or partly substitute whole animal experimentation. Princip les and procedures for safety testing of residues of agrochemicals in food as applied during the last three decades, constitute a 'safety-fi rst' approach, providing sufficient safety margins for the consumer of foods which may contain low levels of residues of agrochemicals.