The health significance of pesticide variability in individual commodity items.

The observed phenomenon of variability of residues in individual fruit and vegetables has a number of implications for risk assessment. The main implication is that the possibility of acute toxic effects in humans has to be considered, where items are commonly consumed unprocessed, are commonly consumed at a single sitting and the pesticide involved has substantial acute toxicity. The main groups of pesticides of concern are the anticholinesterase organophosphates and carbamates. The problem partly arises from the fact that, with some older pesticides, studies of the type most appropriate for setting acute reference doses (ARfDs) have not been carried out. As a result ARfDs are based on studies of length that is greater than ideal. While there is little evidence from the scientific or medical literature that food-borne pesticide poisoning is occurring on any major scale, the symptomatology of such poisoning would be non-specific and the pattern in the population, sporadic. Hence it is likely that pesticide-related illness, through food, would be missed. It is concluded that risk assessments should be improved, using refined safety factors, more appropriate studies and better intake data. The reasons for the variability could be sought and remedied or the application conditions of the pesticide modified.