A first approximation to the adjustment of pesticide use and theoretical MRL's and ADI accomplishment in fruits and vegetables in Uruguay

Abstract

Pesticide residues in fruits and vegetables (F&V) are of primary concern as these foods can be usually consumed as such. Little if any processing is done before their consumption apart from peeling and washing, depending on the type of F&V considered. Because of that, monitoring programs are performed all over the world to ensure legal MRL's accomplishment. The MRLs pursue two main objectives: to enforce Good Agricultural Practices accomplishment and protect consumers' health. In Uruguay, the number of legally allowed pesticides dropped from 453 to 285 active principles during the past decade. For instance, no pesticide of toxicological Level I is permitted in the country. In this work, thorough research on the active principles employed in Uruguay in F&V was performed. Of 233 pesticides registered for the 35 most cultured and consumed F&V in the country, 72 are insecticides, 60 are fungicides, and 101 herbicides. Among the insecticides, 20 were OPs, 10 carbamates, 11 pyrethroids, 6 neonicotinoids, and 25 belong to other chemical classes (matrine, azadirachtin, spinosad, abamectin, chlorantraniliprole a.o.). Most of the 60 fungicides active principles belong to the dithiocarbamates, Cyt-P450 inhibitors, and strobilurins chemical classes. A deterministic approach for evaluating chronic dietary risk for pesticide intake was performed following the recommended procedures by the World Health Organization (WHO) for chlorpyrifos, an insecticide from the organophosphate class, and the two most employed dithiocarbamates in Uruguay: Mancozeb and Ziram. The National Maximum Theoretical Daily Intake (IDTMN) was calculated using consumption data of fruits and vegetables of the National Survey of Household Expenditure and Income (ENGIHS), the Accepted Daily Intake (ADI), and the Maximum Residue Limits (MRL). As a result of the deterministic analysis, chlorpyrifos theoretical intake represented 92% of the IDA value below the safety limits. Nevertheless, as chlorpyrifos is allowed to be used in other highly consumed commodities such as cereals and grains, the maximum value of IDA for it can be easily reachable. In the case of dithiocarbamates, the results varied depending on the studied compound. The MRL for the whole chemical class is expressed as mg of CS 2 /kg sample, and correction factors for each specific compound must be applied to assess dietary risk assessment. Within this context, Mancozeb represented 48% of the IDA and Ziram 427% IDA. The results of a monitoring program on a seasonal basis of pesticide residues in fruits and vegetables will be presented to refine the values obtained with the theoretical calculations; aiming to verify the adjustment of the established MRLs to the Uruguayan diet will be presented and discussed.