FOOD PLANT TOXICANTS AND SAFETY - RISK ASSESSMENT AND REGULATION OF INHERENT TOXICANTS IN PLANT FOODS

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food pla nt toxicants: The margin between actual intake and potentially toxic l evels is often small; application of the default uncertainty factors u sed to derive ADI values, particularly when extrapolating from animal data, would prohibit the utilisation of the food, which may have an ov erall beneficial health effect. Levels of inherent toxicants are diffi cult to control; their complete removal is not always wanted, due to t heir function for the plant or for human health. The health impact of the inherent toxicant is often modified by factors in the food, e.g. t he bioavailability from the matrix and interaction with other inherent constituents. Risk-benefit analysis should be made for different cons umption scenarios, without the use of uncertainty factors. Crucial in this approach is analysis of the toxicity of the whole foodstuff. The relationship between the whole foodstuff and the pure toxicant is expr essed in the product correction factor' (PCF). Investigations in human s are essential so that biomarkers of exposure and for effect can be u sed to analyse the difference between animals and humans and between t he food and the pure toxicant. A grid of the variables characterising toxicity is proposed, showing their inter-relationships. A flow diagra m for risk estimate is provided, using both toxicological and epidemio logical studies. (C) 1998 Elsevier Science B.V. All rights reserved.