Pesticide Exposure of Residents Living Close to Agricultural Fields in the Netherlands: Protocol for an Observational Study

Implication of Pyrethroid Neurotoxicity for Human Health: A Lesson from Animal Models

Pyrethroids, synthetic insecticides used in pest management, pose health risks, particularly neurotoxic effects, with studies linking exposure to a neurodegenerative disorder. This review examines the neurotoxic mechanisms of pyrethroids analyzing literature from animal model studies. It identifies critical targets for neurotoxicity, including ion channels, oxidative stress, inflammation, neuronal cell loss, and mitochondrial dysfunction. The review also discusses key therapeutic targets and signaling pathways relevant to Pyrethroids neurotoxicity management, including calcium, Wnt/β-catenin, mTOR, MAPK/Erk, PI3K/Akt, Nrf2, Nurr1, and PPARγ. Our findings demonstrate that pyrethroid exposure triggers multiple neurotoxic pathways that bear resemblance to the mechanisms underlying neurotoxicity. Oxidative stress and inflammation emerge as prominent factors that contribute to neuronal degeneration, alongside disrupted mitochondrial function. The investigation highlights the significance of ion channels as primary neurodegeneration targets while acknowledging the potential involvement of various other receptors and enzymes that may exacerbate neurological damage. Additionally, we elucidate how pyrethroids may interfere with therapeutic targets associated with neuronal dysfunction, potentially impairing treatment efficacy.Also, exposure to these chemicals can alter DNA methylation patterns and histone modifications, ultimately leading to changes in gene expression that may enhance susceptibility to neurological disorders. Pyrethroid neurotoxicity poses a significant public health risk, necessitating future research for protective strategies against pesticide-induced neurological disorders and understanding the interplay between neurodegenerative diseases, potentially leading to innovative therapeutic interventions.

A Comprehensive Review on Pesticide Residues in Human Urine

Numerous studies worldwide have evaluated pesticide residues detected in urine. This review serves as a contribution to this field by presenting an overview of scientific research studies published from 2001 to 2023, including details of study characteristics and research scope. Encompassing 72 papers, the review further delves into addressing key challenges in study design and method used such as sampling and analytical approaches, results adjustments, risk assessment, estimations, and results evaluation. The review explores urinary concentrations and detection frequency of metabolites of organophosphates and pyrethroids, as well as herbicides such as 2,4-D and glyphosate and their metabolites, across various studies. The association of the results with demographic and lifestyle variables were explored. While farmers generally have higher pesticide exposure, adopting organic farming practices can reduce the levels of pesticides detected in their urine. Residence close to agricultural areas has shown high exposure in some cases. Dietary exposure is especially high among people adopting a conventionally grown plant-rich dietary pattern. A higher detection level and frequency of detection are generally found in females and children compared to males. The implications of transitioning to organic and sustainable plant-rich diets for reducing pesticide exposure and potential health benefits for both adults and children require further investigation.

Urinary pesticide mixture patterns and exposure determinants in the adult population from the Netherlands and Switzerland: Application of a suspect screening approach

INTRODUCTION

Non-occupational sources of pesticide exposure may include domestic pesticide usage, diet, occupational exposure of household members, and agricultural activities in the residential area. We conducted a study with the ambition to characterize pesticide mixture patterns in a sample of the adult population of the Netherlands and Switzerland, using a suspect screening approach and to identify related exposure determinants.

METHODS

A total of 105 and 295 adults participated in the Dutch and Swiss studies, respectively. First morning void urine samples were collected and analyzed in the same laboratory. Harmonized questionnaires about personal characteristics, pesticide-related activities, and diet were administered. Detection rates and co-occurrence patterns were calculated to explore internal pesticide exposure patterns. Censored linear and logistic regression models were constructed to investigate the association between exposure and domestic pesticide usage, consumption of homegrown and organic foods, household members' exposure, and distance to agricultural and forest areas.

RESULTS

From the 37 detected biomarkers, 3 (acetamiprid (-CH2), chlorpropham (4-HSA), and flonicamid (-C2HN)) were detected in ≥40% of samples. The most frequent combination of biomarkers (acetamiprid-flonicamid) was detected in 22 (5.5%) samples. Regression models revealed an inverse association between high organic vegetable and fruit consumption and exposure to acetamiprid, chlorpropham, propamocarb (+O), and pyrimethanil (+O + SO3). Within-individual correlations in repeated samples (summer/winter) from the Netherlands were low (≤0.3), and no seasonal differences in average exposures were observed in Switzerland.

CONCLUSION

High consumption of organic fruit and vegetables was associated with lower pesticide exposure. In the two countries, detection rates and co-occurrence were typically low, and within-person variability was high. Our study results provide an indication for target biomarkers to include in future studies aimed at quantifying urinary exposure levels in European adult populations.

The Effect of Pesticide Spray Season and Residential Proximity to Agriculture on Glyphosate Exposure among Pregnant People in Southern Idaho, 2021

BACKGROUND

Glyphosate is one of the most heavily used pesticides in the world, but little is known about sources of glyphosate exposure in pregnant people living in agricultural regions.

OBJECTIVE

Our objective was to evaluate glyphosate exposure during pregnancy in relation to residential proximity to agriculture as well as agricultural spray season.

METHODS

We quantified glyphosate concentrations in 453 urine samples collected biweekly from a cohort of 40 pregnant people in southern Idaho from February through December 2021. We estimated each participant's glyphosate exposure as the geometric mean (GM) of glyphosate concentrations measured in all samples (average n = 11 samples/participant), as well as the GM of samples collected during the pesticide "spray season" (defined as those collected 1 May-15 August; average n = 5 samples/participant) and the "nonspray season" (defined as those collected before 1 May or after 15 August; average n = 6 samples/participant). We defined participants who resided < 0.5 km from an actively cultivated agriculture field to live "near fields" and those residing ≥ 0.5 km from an agricultural field to live "far from fields" (n = 22 and 18, respectively).

RESULTS

Among participants living near fields, urinary glyphosate was detected more frequently and at significantly increased GM concentrations during the spray season in comparison with the nonspray season (81% vs. 55%; 0.228 μ g / L vs. 0.150 μ g / L , p < 0.001 ). In contrast, among participants who lived far from fields, neither glyphosate detection frequency nor GMs differed in the spray vs nonspray season (66% vs. 64%; 0.154 μ g / L vs. 0.165 μ g / L , p = 0.45 ). Concentrations did not differ by residential proximity to fields during the nonspray season (0.154 μ g / L vs. 0.165 μ g / L , for near vs. far, p = 0.53 ).

DISCUSSION

Pregnant people living near agriculture fields had significantly increased urinary glyphosate concentrations during the agricultural spray season than during the nonspray season. They also had significantly higher urinary glyphosate concentrations during the spray season than those who lived far from agricultural fields at any time of year, but concentrations did not differ during the nonspray season. These findings suggest that agricultural glyphosate spray is a source of exposure for people living near fields. https://doi.org/10.1289/EHP12768.

Impact of occupational pesticide exposure on the human gut microbiome

The rising use of pesticides in modern agriculture has led to a shift in disease burden in which exposure to these chemicals plays an increasingly important role. The human gut microbiome, which is partially responsible for the biotransformation of xenobiotics, is also known to promote biotransformation of environmental pollutants. Understanding the effects of occupational pesticide exposure on the gut microbiome can thus provide valuable insights into the mechanisms underlying the impact of pesticide exposure on health. Here we investigate the impact of occupational pesticide exposure on human gut microbiome composition in 7198 participants from the Dutch Microbiome Project of the Lifelines Study. We used job-exposure matrices in combination with occupational codes to retrieve categorical and cumulative estimates of occupational exposures to general pesticides, herbicides, insecticides and fungicides. Approximately 4% of our cohort was occupationally exposed to at least one class of pesticides, with predominant exposure to multiple pesticide classes. Most participants reported long-term employment, suggesting a cumulative profile of exposure. We demonstrate that contact with insecticides, fungicides and a general "all pesticides" class was consistently associated with changes in the gut microbiome, showing significant associations with decreased alpha diversity and a differing beta diversity. We also report changes in the abundance of 39 different bacterial taxa upon exposure to the different pesticide classes included in this study. Together, the extent of statistically relevant associations between gut microbial changes and pesticide exposure in our findings highlights the impact of these compounds on the human gut microbiome.

Application of human biomonitoring data to support policy development, raise awareness and environmental public health protection among countries within the HBM4EU project

Most countries have acknowledged the importance of assessing and quantifying their population's internal exposure from chemicals in air, water, soil, food and other consumer products due to the potential health and economic impact. Human biomonitoring (HBM) is a valuable tool which can be used to quantify such exposures and effects. Results from HBM studies can also contribute to improving public health by providing evidence of individuals' internal chemical exposure as well as data to understand the burden of disease and associated costs thereby stimulating the development and implementation of evidence-based policy. To have a holistic view on HBM data utilisation, a multi-case research approach was used to explore the use of HBM data to support national chemical regulations, protect public health and raise awareness among countries participating in the HBM4EU project. The Human Biomonitoring for Europe (HBM4EU) Initiative (https://www.hbm4eu.eu/) is a collaborative effort involving 30 countries, the European Environment Agency (EEA) and the European Commission (contracting authority) to harmonise procedures across Europe and advance research into the understanding of the health impacts of environmental chemical exposure. One of the aims of the project was to use HBM data to support evidence based chemical policy and make this information timely and directly available for policy makers and all partners. The main data source for this article was the narratives collected from 27 countries within the HBM4EU project. The countries (self-selection) were grouped into 3 categories in terms of HBM data usage either for public awareness, policy support or for the establishment HBM programme. Narratives were analysed/summarised using guidelines and templates that focused on ministries involved in or advocating for HBM; steps required to engage policy makers; barriers, drivers and opportunities in developing a HBM programme. The narratives reported the use of HBM data either for raising awareness or addressing environmental/public health issues and policy development. The ministries of Health and Environment were reported to be the most prominent entities advocating for HBM, the involvement of several authorities/institutions in the national hubs was also cited to create an avenue to interact, discuss and gain the attention of policy makers. Participating in European projects and the general population interest in HBM studies were seen as drivers and opportunities in developing HBM programmes. A key barrier that was cited by countries for establishing and sustaining national HBM programmes was funding which is mainly due to the high costs associated with the collection and chemical analysis of human samples. Although challenges and barriers still exist, most countries within Europe were already conversant with the benefits and opportunities of HBM. This article offers important insights into factors associated with the utilisation of HBM data for policy support and public awareness.

Do cats mirror their owner? Paired exposure assessment using silicone bands to measure residential PAH exposure

It has been suggested that domestic animals can serve as sentinels for human exposures. In this study our objectives were to demonstrate that i) silicone collars can be used to measure environmental exposures of (domestic) animals, and that ii) domestic animals can be used as sentinels for human residential exposure. For this, we simultaneously measured polycyclic aromatic hydrocarbons (PAHs) using silicone bands worn by 30 pet cats (collar) and their owner (wristband). Collars and wristbands were worn for 7 days and analyzed via targeted Gas Chromatography-Mass Spectrometry (GC-MS). Demographics and daily routines were collected for humans and cats. Out of 16 PAHs, 9 were frequently detected (>50% of samples) in both wristbands and collars, of which Phenanthrene and Fluorene were detected in all samples. Concentrations of wristbands and collars were moderately correlated for these 9 PAHs (Median Spearman's r = 0.51 (range 0.16-0.68)). Determinants of PAH concentrations of cats and humans showed considerable overlap, with vacuum cleaning resulting in higher exposures and frequent changing of bed sheets in lower exposures. This study adds proof-of-principle data for the use of silicone collars to measure (domestic) animal exposure and shows that cats can be used as sentinels for human residential exposure.

Pesticide Exposure of Residents Living in Wine Regions: Protocol and First Results of the Pestiprev Study

The PESTIPREV study has been designed to investigate residential exposure to pesticides applied to vines and ultimately propose mitigation measures. A feasibility study was carried out to validate a protocol for measuring six pesticides in three houses located near vineyards in July 2020. Samples included indoor and outdoor surfaces sampled with wipes (n = 214), patches on the resident's skin (n = 7), hand or foot washing (n = 5), and pets sampled using wipes (n = 2). Limits of quantification for wipes ranged between 0.02 ng for trifloxystrobin and 1.50 ng for pyraclostrobin. Tebuconazole and trifloxystrobin were quantified in nearly 100% of the surface samples, whereas the other fungicides were less frequently found (from 39.7% for pyraclostrobin to 55.1% for boscalid). The median surface loadings ranged from 3.13 ng/m² for benalaxyl to 82.48 ng/m² for cymoxanil. The pesticides most frequently quantified in hand washing, patch samples, and pet wipes were the same as those quantified on surfaces. Finally, the analyses proved to be successful. The tools developed to collect information on determinants were well completed. The protocol was well received by the participants and appeared to be feasible and relevant to the objective of the PESTIPREV study, although some improvements have been identified. It was applied on a larger scale in 2021 to study the determinants of pesticide exposure.

Developing human biomonitoring as a 21st century toolbox within the European exposure science strategy 2020-2030

Human biomonitoring (HBM) is a crucial approach for exposure assessment, as emphasised in the European Commission's Chemicals Strategy for Sustainability (CSS). HBM can help to improve chemical policies in five major key areas: (1) assessing internal and aggregate exposure in different target populations; 2) assessing exposure to chemicals across life stages; (3) assessing combined exposure to multiple chemicals (mixtures); (4) bridging regulatory silos on aggregate exposure; and (5) enhancing the effectiveness of risk management measures. In this strategy paper we propose a vision and a strategy for the use of HBM in chemical regulations and public health policy in Europe and beyond. We outline six strategic objectives and a roadmap to further strengthen HBM approaches and increase their implementation in the regulatory risk assessment of chemicals to enhance our understanding of exposure and health impacts, enabling timely and targeted policy interventions and risk management. These strategic objectives are: 1) further development of sampling strategies and sample preparation; 2) further development of chemical-analytical HBM methods; 3) improving harmonisation throughout the HBM research life cycle; 4) further development of quality control / quality assurance throughout the HBM research life cycle; 5) obtain sustained funding and reinforcement by legislation; and 6) extend target-specific communication with scientists, policymakers, citizens and other stakeholders. HBM approaches are essential in risk assessment to address scientific, regulatory and societal challenges. HBM requires full and strong support from the scientific and regulatory domain to reach its full potential in public and occupational health assessment and in regulatory decision-making.

Pesticides in doormat and floor dust from homes close to treated fields: Spatio-temporal variance and determinants of occurrence and concentrations

Indoor dust has been postulated as an important matrix for residential pesticide exposure. However, there is a lack of information on presence, concentrations and determinants of multiple pesticides in dust in residential homes close to treated fields. Our objective was to characterize the spatial and temporal variance of pesticides in house dust, study the use of doormats and floors as proxies for pesticides in indoor dust and identify determinants of occurrence and concentrations. Homes within 250 m from selected bulb fields were invited to participate. Homes within 20 km from these fields but not having agricultural fields within 500 m were selected as controls. House dust was vacuumed in all homes from floors (VFD) and from newly placed clean doormats (DDM). Sampling was done during two periods, when pesticides are used and not-used. For determination of 46 prioritized pesticides, a multi-residue extraction method was used. Most statistical analyses are focused on the 12 and 14 pesticides that were detected in >40% of DDM and VFD samples, respectively. Mixed models were used to evaluate relationships between possible determinants and pesticides occurrence and concentrations in DDM and VFD. 17 pesticides were detected in more than 50% of the homes in both matrixes. Concentrations differed by about a factor five between use and non-use periods among homes within 250 m of fields and between these homes and controls. For 7 pesticides there was a moderate to strong correlation (Spearman rho 0.30-0.75) between concentrations in DDM and VFD. Distance to agricultural fields and air concentrations were among the most relevant predictors for occurrence and levels of a given pesticide in DDM. Concentrations in dust are overall higher during application periods and closer to fields (<250 m) than further away. The omnipresence of pesticides in dust lead to residents being exposed all year round.

A Critical Scoping Review of Pesticide Exposure Biomonitoring Studies in Overhead Cultures

The exposure of operators, workers, residents and bystanders to pesticides is of high potential concern. Yet, reports on pesticide residues in the environment and near treated fields often spark debates if such findings might indicate a health risk. Although the underlying models are considered conservative, there are only limited field data on systemic exposure available. As a first step to improve the situation, we conducted a scoping review of state-of-the-art pesticide exposure biomonitoring studies in operators, workers, residents or bystanders. In contrast to existing reviews, we focused on target cultures of potential high pesticide exposure such as tree-grown produce, vine or hops. The search was conducted in Web of Science, Scopus and PubMed. Out of 17 eligible articles, a total of 11 studies met our search criteria, and 6 of them quantified the systemic exposure of humans. The analysis revealed that exposure was mainly driven by application of pesticides and reentry work, resulting in a higher exposure of operators and workers than of residents and bystanders. In nearly all cases, the systemic exposure was below the relevant toxicological reference values. The studies were subsequently analyzed to identify key criteria for a reliable design of a biomonitoring study on pesticide exposure.

Collection of human and environmental data on pesticide use in Europe and Argentina: Field study protocol for the SPRINT project

Current farm systems rely on the use of Plant Protection Products (PPP) to secure high productivity and control threats to the quality of the crops. However, PPP use may have considerable impacts on human health and the environment. A study protocol is presented aiming to determine the occurrence and levels of PPP residues in plants (crops), animals (livestock), humans and other non-target species (ecosystem representatives) for exposure modelling and impact assessment. To achieve this, we designed a cross-sectional study to compare conventional and organic farm systems across Europe. Environmental and biological samples were/are being/will be collected during the 2021 growing season, at 10 case study sites in Europe covering a range of climate zones and crops. An additional study site in Argentina will inform the impact of PPP use on growing soybean which is an important European protein-source in animal feed. We will study the impact of PPP mixtures using an integrated risk assessment methodology. The fate of PPP in environmental media (soil, water and air) and in the homes of farmers will be monitored. This will be complemented by biomonitoring to estimate PPP uptake by humans and farm animals (cow, goat, sheep and chicken), and by collection of samples from non-target species (earthworms, fish, aquatic and terrestrial macroinvertebrates, bats, and farm cats). We will use data on PPP residues in environmental and biological matrices to estimate exposures by modelling. These exposure estimates together with health and toxicity data will be used to predict the impact of PPP use on environment, plant, animal and human health. The outcome of this study will then be integrated with socio-economic information leading to an overall assessment used to identify transition pathways towards more sustainable plant protection and inform decision makers, practitioners and other stakeholders regarding farming practices and land use policy.