CARCINOGENS IN FOOD - PRIORITIES FOR REGULATORY ACTION

A pragmatic possible approach to the prioritization of chemical carcin ogens occurring as food contaminants is described, based on the carcin ogenic risk to the population. This should be of value in ensuring tha t resources for assessment and management of carcinogens in food are d irected to the most important areas with regard to carcinogenic risk t o the population. Key components of this approach are an assessment of the carcinogenic hazard to humans combined with estimations of intake s per person and of the proportion of the population exposed. These ar e used to derive an index referred to as the Population Carcinogenic I ndex. Concerning the hazard assessment expert judgement is used to pla ce the chemical in one of five categories. The highest category is for chemical carcinogens that are believed to act by a genotoxic mechanis m. It is recognised that such compounds may vary enormously with respe ct to their potency and various approaches to ranking carcinogens on t he basis of potency are reviewed. The approach adopted is to subdivide the genotoxic carcinogens category into high, medium and low potency based on the TD50 value. Methods of estimating intakes and exposed pop ulations are considered and an approach which groups these into broad categories is developed. The hazard and exposure assessments are then combined to derive the Population Carcinogenicity Index.