Refining customer exposure due to pesticide residues – Part 1

Friday, October 2, 2015

Andrea Zentai, Kata Kerekes, István Szabó, Árpád Ambrus


1. Summary

The targeted use patterns of pesticides are evaluated, in relation to the safety of consumers based on the results of supervised trials performed before registration, The dietary intake of the relevant resiudes is calculated with the so called deterministic method providing only a point estimate. Customer exposure can be determined more realistically and in a more refined way based on the results of monitoring programmes performed following practical application of the pesticides, especially by using probabilistic calculation procedures gaining ground gradually in practical applications. In addition to consumption data of the crops treated, for crops of medium size, their individual weight distribution and the variability factor expressing the relationship of pesticide residues in the individual units and the average residues in the samples are required for calculations performed by both methods. For the latter two parameters, only limited data are available from a few countries.


To refine the methodology of probabilistic exposure assessment, we determined the individual weight distributions of nearly 50 fruits and vegetables available in Hungary, and the variability of pesticide residues in crop units, based on data from our international research programs. In the first part of our work, basic principles of the deterministic and probabilistic procedures, the individual weight distributions of the crops, and their characteristic

properties are described.


2. Introduction

The use of pesticides is unavoidable in order to be able to provide crops of adequate quality and quantity to the ever-growing population of our Earth. Based on widespread preliminary testing prior to strict authorization procedures [1], [2], [3], [4], [5], pesticide residues that remain in the crops under recommended use conditions do not present a health risk. Results of a large number of monitoring analyses following the use of pesticides confirm that their residues are not the biggest food safety problem we face today. The report of the European Food Safety Authority (EFSA) about the 2013 monitoring results performed in 27 countries with reporting obligations [6] indicates that 54.6% of the 80967 samples analyzed for 685 different pesticide residues did not contain pesticide residues in detectable amounts. The frequency of samples containing pesticide residues in amounts exceeding permitted maximum residue limits was only a few percent, while the rate of positive samples with pesticide residues exceeding the health threshold limit values was even lower. Despite these results, pesticide residues are considered the main food safety threat by the population of many countries. For example, according to a 2010 Eurobarometer survey, 84% of the Hungarian population found the presence of pesticide residues in foods very alarming [7].


Short-term acute exposure of consumers and chronic exposure during the entire human lifetime are estimated by a deterministic method on the international level. Maximum expected pesticide residue concentrations in the treated crops under recommended use conditions serve as a basis for the estimations. Estimated values are compared to the acute reference dose (ARfD) and the acceptable daily intake (ADI) value concerning the entire human lifespan. The procedures applied by the JMPR expert committee of FAO/WHO [8] and the EFSA [9] are essentially the same, and both provide adequate safety for consumer protection.

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