The ACROPOLIS project: Its aims, achievements, and way forward

Cumulative risk assessment with pesticides in the framework of MRL setting

This abstract presents a report on the proposed work programme, focus on cumulative risk assessment (CRA) for chemical risks, specifically pesticide residues in food. While not a scientific publication, this technical report aims to provide insights without including the fellow's data to avoid publication restrictions. This report focuses on addressing the question concerning the trigger value to perform a prospective CRA in case of a new maximum residue level (MRL) setting. The 1,000 margin of exposure (MOE) threshold value was tested and compared to preliminary ANSES results. Alternative thresholds were calculated and explored. The EU-FORA fellow selected two cumulative assessment groups (CAGs) related to acute craniofacial alterations and chronic thyroid effects. The fellow performed exposure assessments, integrating effects data, French monitoring data, processing factors, agricultural uses, MRLs and extrapolations into Monte Carlo risk assessment (MCRA). Retrospective cumulative exposures using MCRA were conducted for children, adults and a vulnerable group of childbearing women based on the French survey INCA3, identifying background levels at P99.9. The fellow also performed prospective assessments with MCRA, analysing results at P99.9 to evaluate the adequacy of the 1,000 MOE threshold. Alternative thresholds are discussed and proposed.

Association between occupational and environmental pesticide exposure in Cukurova region by hair and blood biomonitoring

This study assesses association between occupational and environmental pesticide exposure on pesticide applicators directly exposed to pesticides and inhabitants of the Cukurova region by analyzing blood and hair samples. Hair and blood samples were collected from 132 volunteers, 66 of whom are pesticide applicators, and the rest are non-farmer residents, in 10 villages nearby the Ceyhan River between March and June in 2017. Samples were then analyzed via the liquid chromatography-tandem mass spectrometer. As the analysis result, a total number of 31 pesticides were detected in hair samples, whereas a total number of 15 pesticides were observed in blood samples. Twenty of the pesticides (64.5%) detected in the hair and 3 (20%) detected in the blood were significantly higher in the applicators than the non-farm residents. Also, 5 pesticides (16.1%) observed in the hair and 7 observed (46.6%) in the blood were banned pesticides. This study investigated the pesticide exposures on people living in the region via hair and blood samples. Our study revealed that, in addition to individuals who are occupationally exposed to pesticides, individuals from all parts of the society, especially those living in the agricultural region, have a certain level of pesticide exposure.

Cumulative Pesticides Exposure of Children and Their Parents Living near Vineyards by Hair Analysis

The aim of the present work was the application of hair biomonitoring to investigate exposure to pesticides in children and their parents residing in a vineyard area. Thirty-three children and 16 parents were involved in the study. Hair samples were self-collected before and after the application season (PRE- and POST-EXP samples). Information on study subjects and the use of pesticides in the area were obtained. Thirty-nine pesticides were analyzed by liquid chromatography tandem mass spectrometry, and thirty-one pesticides were quantifiable in at least one hair sample. Most frequently detected pesticides were chlorpyrifos, cycloxidim, dimethomorph, metalaxyl, spiroxamine, and tetraconazole. From PRE-EXP to POST-EXP the percentage of quantification and/or the concentration of pesticides increased; the concentration was typically in the low pg/mg hair range with comparable levels in children and parents. An inverse correlation was found between the total exposure to pesticides in POST-EXP hair samples and the distance between home and the treated fields (Spearman ρ = -0.380, p = 0.01). The results of this study show that the majority of the study pesticides were measured in the hair of subjects living in the close proximity of treated vineyards, supporting the determination of pesticides in hair for the purpose of biomonitoring cumulative exposure in the general population.

Optical Screening Methods for Pesticide Residue Detection in Food Matrices: Advances and Emerging Analytical Trends

Pesticides have been extensively used in agriculture to protect crops and enhance their yields, indicating the need to monitor for their toxic residues in foodstuff. To achieve that, chromatographic methods coupled to mass spectrometry is the common analytical approach, combining low limits of detection, wide linear ranges, and high accuracy. However, these methods are also quite expensive, time-consuming, and require highly skilled personnel, indicating the need to seek for alternatives providing simple, low-cost, rapid, and on-site results. In this study, we critically review the available screening methods for pesticide residues on the basis of optical detection during the period 2016-2020. Optical biosensors are commonly miniaturized analytical platforms introducing the point-of-care (POC) era in the field. Various optical detection principles have been utilized, namely, colorimetry, fluorescence (FL), surface plasmon resonance (SPR), and surface enhanced Raman spectroscopy (SERS). Nanomaterials can significantly enhance optical detection performance and handheld platforms, for example, handheld SERS devices can revolutionize testing. The hyphenation of optical assays to smartphones is also underlined as it enables unprecedented features such as one-click results using smartphone apps or online result communication. All in all, despite being in an early stage facing several challenges, i.e., long sample preparation protocols or interphone variation results, such POC diagnostics pave a new road into the food safety field in which analysis cost will be reduced and a more intensive testing will be achieved.

A retain and refine approach to cumulative risk assessment

Mixtures of substances to which humans are exposed may lead to cumulative exposure and health effects. To study their effects, it is first necessary to identify a cumulative assessment group (CAG) of substances for risk assessment or hazard testing. Excluding substances from consideration before there is sufficient evidence may underestimate the risk. Conversely, including everything and treating the inevitable uncertainties using conservative assumptions is inefficient and may overestimate the risk, with an unknown level of protection. An efficient, transparent strategy is described to retain a large group, quantifying the uncertainty of group membership and other uncertainties. Iterative refinement of the CAG then focuses on adding information for the substances with high probability of contributing significantly to the risk. Probabilities can be estimated using expert opinion or derived from data on substance properties. An example is presented with 100 pesticides, in which the retain step identified a single substance to target refinement. Using an updated hazard characterisation for this substance reduced the mean exposure estimate from 0.43 to 0.28 μg kg-bw^-1 day^-1 and reduced the 99.99th percentile exposure from 24.9 to 5.1 μg kg-bw^-1 day^-1. Other retained substances contributed little to the risk estimates, even after accounting for uncertainty.

Hair as a matrix to evaluate cumulative and aggregate exposure to pesticides in winegrowers

INTRODUCTION

Vineyard is a crop where a large number of pesticides are applied; exposure to pesticides may occur in farmers and the general population living close to the treated area. This work aimed to investigate hair as a matrix for the assessment of cumulative and aggregate exposure to pesticides in potentially exposed individuals.

METHODS

Twenty agricultural workers (AW), 4 agricultural worker relatives (AR), and 5 research staff members (RS) were involved in the study. Hair samples were collected before and after the application season (PRE- and POST-EXP samples) to obtain 18 paired samples. Records with the name and the quantity of applied pesticides were obtained; twenty-seven pesticides were measured in hair by solvent extraction and LC-MS/MS.

RESULTS

During the study season, AW applied 14 different pesticides with median amount ranging from 12 to 7200 g. The most popular pesticides were dimethomorph, penconazole, cyazofamid, fenamidone and quinoxyfen, applied from 94 to 69% of AW. In AW, in PRE-EXP samples the majority of used pesticides was detectable (with detection rates from 6 to 88%), with median concentrations of few pg/mg hair; in the POST-EXP samples the frequency of detected values increased (from 25 to 100%), with median concentrations up to two orders of magnitude higher. In AR, most pesticides were quantifiable only in POST-EXP samples and with lower concentration in comparison with AW; in RS, in both PRE- and POST-EXP samples only a few pesticides were quantifiable with very low levels. In AW, a linear correlation (r = 0.682 on log-transformed data, p < 0.01) was found between the total amounts of applied pesticides during the season and their concentration in hair.

CONCLUSION

The study shows that the majority of assessed pesticides was incorporated into hair of AW and AR. The increased frequency of detection and level at the end of the season and the correlation between pesticide in hair and the amount of applied pesticides, reinforce the use of hair for quantitative biomonitoring of cumulative exposure to pesticides.

Modelling aggregate exposure to pesticides from dietary and crop spray sources in UK residents

Human exposure to pesticide mixtures can occur from the diet and other sources. Realistic exposure and risk assessments should include multiple sources and compounds and include the relative hazards of the different compounds. The EU-funded Euromix project is developing new web-based tools to facilitate these calculations. A case study is presented that exemplifies their use for a population of UK residents, including exposure from crop-spraying. A UK pesticide usage survey provided information on real pesticide combinations applied to crops of wheat, potatoes, sugar beet and dessert apples. This information was combined with outputs from two alternative simulation models of spray drift to estimate dermal, oral and inhalation exposures of residents. These non-dietary exposures were combined with dietary exposure estimates using the Monte Carlo Risk Assessment software to produce a distribution of aggregated and cumulative exposures. Compounds are weighted by relative potency to generate a measure of overall risk. Uncertainty quantification was also included in the distribution of exposures. These tools are flexible to allow diverse sources of exposure and can provide important information to decision-makers and help to prioritise testing of pesticide mixtures. Including non-dietary sources changed the prioritisation of pesticide mixtures, when compared to dietary exposure alone.

Comprehensive European dietary exposure model (CEDEM) for food additives

European methods for assessing dietary exposures to nutrients, additives and other substances in food are limited by the availability of detailed food consumption data for all member states. A proposed comprehensive European dietary exposure model (CEDEM) applies summary data published by the European Food Safety Authority (EFSA) in a deterministic model based on an algorithm from the EFSA intake method for food additives. The proposed approach can predict estimates of food additive exposure provided in previous EFSA scientific opinions that were based on the full European food consumption database.

The potential application of a biomarker approach for the investigation of low-calorie sweetener exposure

Low-calorie sweeteners (LCS) are commonly used as sugar substitutes in the diet to provide a desired sweet taste without increased energy intake. The number of LCS available on the market has increased considerably over the years and despite extensive evaluation of their safety prior to approval, debate continues around the effects of consumption on health. In Europe, Member States are obligated to monitor exposure to LCS and methods currently used tend to rely on self-reported dietary intake data alongside LCS concentrations in products. However, the acquisition of accurate data can be costly in terms of resources and time and are inherently imprecise. Although LCS are intensely sweet, they are chemically diverse and a limitation of many studies investigating the health effects of consumption is that they often fail to discern intakes of individual LCS. An approach which objectively assesses intakes of individual LCS would therefore allow robust investigations of their possible effects on health. Biomarker approaches have been utilised for the objective investigation of intakes of a range of dietary components and the feasibility of any such approach depends upon its validity as well as its applicability within the target population. This review aims to provide an overview of current understanding of LCS intake and explore the possibility of implementing a biomarker approach to enhance such understanding. Several commonly used LCS, once absorbed into the body, are excreted via the kidneys; therefore a urinary biomarker approach may be possible for the investigation of short-term exposure to these compounds.