Pesticide Risk Research Articles

A Survey on Pesticide Residues and Risk Assessment for Agricultural Products Marketed in the Northern Area of Seoul from 2022 to 2023

A Survey on Pesticide Residues and Risk Assessment for Agricultural Products Marketed in the Northern Area of Seoul from 2022 to 2023

Pesticide Contamination in Native North American Crops, Part I-Development of a Baseline and Comparison of Honey Bee Exposure to Residues in Lowbush Blueberry and Cranberry.

A pesticide exposure baseline for honey bees was compiled for two New England cropping systems, the native North American plant species consisting of lowbush blueberry (Vaccinium angustifolium Aiton) and cranberry (Vaccinium macrocarpon Aiton). More unique pesticide compounds were applied in blueberry than cranberry, but the numbers of pesticides discovered in trapped honey bee pollen were similar between the two crop systems. Not all pesticides found in pollen were the result of the applications reported by growers of either crop. When comparing residues, number of pesticides detected, total concentration, and risk quotient varied between the two crops. Also, blueberry was dominated by fungicides and miticides (varroacides) and cranberry was dominated by insecticides and herbicides. When comparing reported grower applications that were matched with detection in residues, the proportion of pesticide numbers, concentrations, and risk quotients varied by crop system and pesticide class. In most cases, pesticide residue concentrations were of low risk (low risk quotient) to honey bees in these crops. Estimation of decay rates of some of the most common pesticide residues under field conditions could aid growers in selection of less persistent compounds, together with safe application dates, prior to bringing in honey bees for pollination.

Environmental fate of monosodium methanearsonate (MSMA)-Part 2: Modeling sequestration and transformation.

Monosodium methanearsonate(MSMA), a sodium salt of monomethylarsonic acid (MMA),is a selective contact herbicide used for the control of a broad spectrum of weeds. In water, MSMA dissociates to ions of sodium (Na+) and monomethylarsonate (MMA-)thatis stable and does not transform abiotically. In soils characteristic of MSMA use, several simultaneous processes can occur: (1) microbial methylation of MMA to dimethylarsinic acid (DMA), (2) microbial demethylation of MMA to inorganic arsenic (iAs), (3) methylation of iAs to MMA, and (4) sorption and sequestration of MMA and its metabolites to soil minerals. Sequestered residues are residues that cannot be desorbed from soil in environmental conditions. Sequestration is rapid in the initial several days after MSMA application and continues at a progressively slower rate over time. Once sequestered, MMA and its metabolites are inaccessible to soil microorganisms and cannot be transformed. The rate and extent of the sorption and sequestration as well as the mobility of MMA and its metabolites depend on the local edaphic conditions. In typical MSMA use areas, the variability of the edaphic conditions is constrained. The goal of this research was to estimate the amount of iAs potentially added to drinking water as a result of the use of MSMA, with models and scenarios developed by the US Environmental Protection Agency for pesticide risk assessment. In this project, the estimated drinking water concentrations (EDWCs) for iAs were assessed as the average concentration in the reservoir over a 30-year simulation with annual applications of MSMA at maximum label rates. When the total area of suitable land was assumed to be treated, EDWCs ranged from <0.001 to 0.12 µg/L. When high estimates of actually treated acreage are considered, the EDWCs are below 0.06 µg/L across all scenarios. Integr Environ Assess Manag 2024;20:2076-2087. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Towards sustainable crop protection in agriculture: A framework for research and policy

CONTEXTEuropean countries have set ambitious targets to reduce the risks of pesticide use. Achieving these targets will require a large proportion of farmers to adopt sustainable crop protection practices. However, how to enable this transition and what are the best policies to support farmers remain open questions. OBJECTIVEHere, we provide a coherent review of existing evidence and new insights into farmer decision-making and policy analysis in the context of the transition to more sustainable crop protection. We synthesise and extend the empirical evidence and the conceptual and methodological foundations to examine farmers' decisions to adopt sustainable crop protection and to assess the potential of different policy measures to support this transition. Our analysis focuses on European agriculture. METHODSWe provide a framework and synthesise evidence by reviewing the literature and combining agronomic and economic perspectives. We focus on three issues: i) indicators for empirical analyses of adoption of sustainable crop protection practices; ii) behavioural perspectives on farmer adoption; iii) insights into methodological approaches for assessing adoption of sustainable crop protection practices and related policies. RESULTS AND CONCLUSIONWe have identified four main findings and implications. First, sustainable crop protection practices consist of combinations and bundles of individual measures that are not currently regularly considered in policy instruments and policy analysis. Second, definitions of adoption should move from simple adoption metrics to impacts, for example on pesticide risk reduction. Third, behavioural factors are highly relevant to farmers' adoption decisions, but are currently under-researched and under-represented in the field of sustainable crop protection practices. Fourth, the tools currently used for policy analysis do not allow these key aspects to be represented. We draw policy conclusions. SIGNIFICANCEOur analyses help guide policy decisions to achieve pesticide use and risk reduction objectives, and have implications for pesticide policy in Europe and beyond. We identify gaps in current conceptual and methodological approaches, promising avenues for future research, and ways to make results more coherent and comparable. Our analysis thus provides new insights and templates to guide future research and policy analysis on the adoption of sustainable crop protection approaches.

Fabrication of dual responsive microcapsules based on starch with enhanced foliar adhesion and photostability for improving control efficacy and reducing environmental risks

Stimuli-responsive controlled release formulations offer a promising avenue for enhancing effective utilization and mitigating environmental risks of pesticides. Herein, pH and enzyme-responsive pesticide microcapsules (AVE@CPS-Fe-TA) were constructed by encapsulating carboxylated porous starch (CPS) loaded with avermectin (AVE) within tannic acid-iron complexes (Fe-TA) to improve the insecticidal efficacy and reduce toxicity to non-targets of AVE. The results showed that the loading content of AVE in the modified starch-based microcapsules could be precisely adjusted by the enzymatic hydrolysis time of starch. The prepared AVE@CPS-Fe-TA had pH and α-amylase dual responsive release properties and exhibited superior photostability, and its photolysis half-life was extended by 15.57-fold compared to AVE technical. Additionally, the leaf retention rate of AVE@CPS-Fe-TA after being rinsed by simulated rainwater was 6.08 times higher than that of commercial formulation AVE EC. In greenhouse insecticidal activity experiment, AVE@CPS-Fe-TA demonstrated a high control efficacy against Ostrinia furnacalis and had a prolonged effective duration. Moreover, AVE@CPS-Fe-TA significantly reduced the acute toxicity of AVE to zebrafish and promoted the growth of maize seedlings. Therefore, this work would provide eco-friendly stimuli-responsive microcapsules of pesticides for improving the efficiency of utilization and reducing environmental risks.

Chronic effects of commercial pesticide preparations on biomarkers and reproductive success in earthworm Eisenia andrei

Chemical pollution resulting from pesticide usage has been a continuous issue since the 1960s, despite comprehensive European Union legislation designed to safeguard human health and the environment from the adverse effects of pesticides. While regulatory risk assessments primarily focus on the active ingredients, recent research indicates ecotoxicological impacts of commercial preparations on non-target organisms, particularly within the soil ecosystem where key species such as earthworms play a vital role in maintaining soil quality and fertility. Therefore, the aim of this study was the assessment of the long-term effects of the following respective commercial preparations: the insecticides Sumialfa (esfenvalerate) and Calypso (thiacloprid), as well as the herbicides Frontier (dimethenamid-p) and Filon (prosulfocarb) on the earthworm Eisenia andrei in standardized soil during long-term exposures of 7, 14, and 28 days. To study the possible effects on different levels of biological organization, enzymatic biomarkers: acetylcholinesterase (AChE), carboxylesterase (CES) glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx); non-enzymatic biomarkers: multixenobiotic resistance activity (MXR), levels of glutathione (GSH), and reactive oxygen species (ROS) as well as reproductive success were investigated. While Calypso appeared to be the least toxic substance, all pesticides showed significant effect on multiobiomarker response in E. fetida. That being said, the response of MXR activity was significantly altered by all tested pesticides indicating MXR being the most sensitive endpoint of the present research. Recovery of MXR was observed after 28 days, however, only in case of exposure to Filon, while the recovery of CAT activity was recorded after 28 days as well, subsequent to Sumialfa exposure. Reproductive success was negatively impacted regarding the Frontier and Sumialfa exposure at the highest concentration (100 mg/kg) reflected in reduced number of cocoons, while only the exposure to Frontier (100 mg/kg) reduced the number of juveniles. Based on the results, it is important to include commercial pesticide formulations in pesticide risk assessments. The toxicity classifications of the studied pesticides suggest the potential detrimental consequences to the key soil species in terrestrial ecosystems at various concentrations. Future studies should include other soil species as well as investigation of higher levels of biological organization, i.e., behavioral endpoints, to determine the potential risks to terrestrial ecosystems.

A Rapid Assessment Technique for Identifying Future Water Use and Pesticide Risks Due to Changing Cropping Patterns

A Rapid Assessment Technique for Identifying Future Water Use and Pesticide Risks Due to Changing Cropping Patterns

Risk perception and use of personal protective equipment (PPE) in pesticide use: does risk shape farmers’ safety behavior?

ABSTRACT Risk perception and use of personal protective equipment (PPE) in pesticide use were studied in 109 farmers of northern Greece. Farmers differed in the levels of pesticide risk perception, with 26.6% showing very low and low levels, 34.9% showing moderate levels, and 38.5% showing high and very high levels. Pesticide risk perception was positively correlated with education and large cultivated area, but negatively with age and non-farming as a main profession. Most farmers (82.6%) showed adequate use of PPE (mostly face mask and gloves). The use of PPE was positively correlated with education and risk perception, but negatively with age and non-farming as a main profession. Farmers with high levels of risk perception used 1.3 and 2.6 times more PPE items than those with moderate and low levels of risk perception, respectively. High education was a positive predictor, whereas main profession other than farming was a negative predictor of PPE use.

Occurrence and inhalation health risk of neonicotinoid pesticides in outdoor air particulate matters from 2019 to 2021 in China

Neonicotinoid insecticides (NNIs), as a new type of insecticide, are widely used in agriculture and daily life. Because of the low volatility of NNIs, few studies have evaluated them in atmospheric particulate matter. In this study, 101 outdoor PM2.5 samples were collected from the Wuhan urban area from 2019 to 2021, leading to the detection of seven NNIs and three of their metabolites. The detection frequencies of all 10 substances were more than 60%, with DIN (dinotefuran) and IMI (imidacloprid) reaching 100%. DIN (52.4 pg/m3) and IMI (43.0 pg/m3) had higher median concentrations than other substances. Concentration distributions of the four substances ACE (acetamiprid), DIN, IMI, and 5-OH-IMI (5-Hydro-Imidacloprid) exhibited statistically significant differences (P < 0.05) across the four seasons. Concentration levels of ACE, CLO (clothianidin), and IMI were statistically different between the three years (P < 0.05). The median concentration of imidacloprid-equivalent total neonicotinoids (IMIeq: generated by the relative potency factor method) was 256.1 pg/m3. Finally, the estimated daily intake (EDI) of NNIs via respiration was greater in infants and young children than in the rest of the population, suggesting that infants and young children were more likely to be exposed to the health effects of airborne residual PM2.5.

Organophosphate pesticide exposure and risk of SARS-CoV-2 infection

Several studies have reported immune modulation by organophosphate (OP) pesticides, but the relationship between OP exposure and SARS-CoV-2 infection is yet to be studied. We used two different measures of OP pesticide exposure (urinary biomarkers (N = 154) and residential proximity to OP applications (N = 292)) to examine the association of early-childhood and lifetime exposure to OPs and risk of infection of SARS-CoV-2 using antibody data. Our study population consisted of young adults (ages 18–21 years) from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) Study, a longitudinal cohort of families from a California agricultural region. Urinary biomarkers reflected exposure from in utero to age 5 years. Residential proximity reflected exposures between in utero and age 16 years. SARS-CoV-2 antibodies in blood samples collected between June 2022 and January 2023 were detected via two enzyme linked immunosorbent assays, each designed to bind to different SARS-CoV-2 antigens. We performed logistic regression for each measure of pesticide exposure, adjusting for covariates from demographic data and self-reported questionnaire data. We found increased odds of SARS-CoV-2 infection among participants with higher urinary biomarkers of OPs in utero (OR = 1.94, 95% CI: 0.71, 5,58) and from age 0–5 (OR = 1.90, 95% CI: 0.54, 6.95).

Analysis in Terms of Environmental Awareness of Farmers’ Decisions and Attitudes: Reducing Pesticide Use and Risks

Pesticide residues are a significant problem affecting the quality and safety of agricultural products in Turkey. This study aims to investigate farmers’ risk perception regarding pesticide residues, including the primary factors that influence their behavior from the farmers’ perspective. In addition, the main characteristics of pesticide residues encountered in the production of agricultural products against the current policy background is investigated to provide decision support to the Turkish government for improving the safe production of agricultural products. This paper uses a binary logistic model to analyze farmers’ perceptions of pesticide residues using a cross-sectional dataset of 323 vegetable growers in Bursa, Turkey. Farmer characteristics and pesticide application behavior were more effective in reducing residual risk perceptions than farm characteristics. The effects of membership in a cooperative, average amount of pesticide used, location where the pesticide was purchased, application timing, and adherence to last spraying and harvest timing on the perception of residues were the largest. Farmers receive helpful but limited information from pesticide distributors. However, the primary source of information is not the advisors, which is why these grievances exist. The study results show that policymakers should support cooperatives, expand pesticide training, and make public extension services more effective and that pesticide dealers should conduct more frequent inspections.

AN ASSESSMENT OF PESTICIDE POISONING INCIDENCES PRESENTED AT HEALTH CARE FACILITIES IN MASHONALAND CENTRAL PROVINCE, ZIMBABWE

Acute Pesticide Poisoning (APP) is a significant problem in developing countries, causing loss of productivity and fatalities in the agricultural sector. However, limited information on the connection between pesticide use, APP, and deaths in Zimbabwe is available. This study aimed to evaluate incidents that resulted in APP and identify the specific pesticides that caused them at Health Care Facilities (HCFs) in Mashonaland Central Province. Researchers conducted a survey asking standardized questions to gather information on APP cases from 93 HCFs. Descriptive statistics and chi-square association tests for APP cases in the targeted HCFs were calculated using IBM SPSS version 22. The study found that 43% of APP cases were due to pesticides belonging to the World Health Organization (WHO) class II acute toxicity category, while 26.1% were caused by Highly Hazardous Pesticides (HHPs). Most of the cases were due to intentional poisoning (87.1%), with the majority (55.9%) of APP incidents being males. The highest APP cases were recorded in the 21-30 age group (38.8%), followed by the 31-40 age group (32.8%). These results emphasize the significant impact of intentional poisoning by WHO class II type pesticides, particularly HHPs, on the incidence of APP in Zimbabwe. To mitigate the impact of HHPs on human health, it is recommended that the government of Zimbabwe consider pesticide risk reduction measures, such as stricter pesticide registration criteria, import restrictions, and the promotion of less toxic alternatives. These findings highlight the urgent need for policymakers, researchers, and other stakeholders in the agricultural sector to work collaboratively towards creating a safer and more sustainable farming environment in Zimbabwe.

The adsorption-desorption behavior of chlorothalonil in the cuticles of apple and red jujube

The distribution fate of chlorothalonil (CHT) in the environment (soil and water) and fruits is controlled by the capacity of cuticles to adsorb and desorb CHT, which directly affects the safety of both the environment and fruits. Batch experiments were conducted to reveal the adsorption-desorption behaviors of CHT in the cuticles of apple and red jujube. The adsorption kinetics showed that both physisorption and chemisorption occurred during the adsorption process. Furthermore, the isothermal adsorption of CHT in the fruit cuticles followed the Freundlich model. The thermodynamic parameters (ΔG ≤ −26.16 kJ/mol, ΔH ≥ 31.05 kJ/mol, ΔS ≥ 0.20 kJ/(mol K) showed that the whole CHT adsorption process was spontaneous, and the hydrophobic interaction was predominant. The CHT adsorption capacity of the apple cuticle was higher than that of the red jujube cuticle, potentially due to the significantly higher alkanes content of apples than that of red jujubes. An appropriate ionic strength (0.01 moL/L) could induce a higher adsorption capacity. In addition, the desorption kinetics were shown to conform to a Quasi-first-order model, meaning that not all the adsorbed CHT could be easily desorbed. The desorption ratios in apple and red jujube cuticles were 41.38% and 35.64%, respectively. The results of Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy further confirmed that CHT could be adsorbed and retained in the fruit cuticles. Investigating the adsorption-desorption behavior of CHT in the apple and red jujube cuticles allowed to determine the ratio of its final distribution in the fruits and environment, providing a theoretical basis to evaluate the risk of residue pesticide.

Seasonal dynamics and ecological risks of organochlorine pesticides in Kafrelsheikh-Egypt: Implications for aquatic ecosystems and public health

Kafrelsheikh, situated in the middle of the Nile Delta, significantly contributes to Egypt's aquaculture and agriculture sectors. However, the local use of organochlorine pesticides (OCPs) in agriculture is often a source of OCP residues in associated drainage waters, which may threaten aquatic ecosystems. These pesticides persist in local water bodies, jeopardizing aquatic ecosystems and potentially impacting human health. This comprehensive study assessed the seasonal variations of 17 OCPs in both water sources and Nile tilapia across eight fish farming locations in Kafrelsheikh. Using gas chromatography coupled with mass spectrometry (GC-MS), we detected OCP concentrations in water that varied seasonally where winter recorded the highest levels at 22.5 ng/mL and, summer showed the lowest levels at 6.2 ng/mL. Despite water samples occasionally showing risk quotients (RQs) greater than 1, indicating a potential threat to aquatic life, the OCP levels in Nile tilapia were sufficiently low, with target hazard quotients (THQ) below 1, suggesting no significant risk for human consumption. The research highlights a pressing need for regular environmental monitoring and stricter regulatory control over pesticide use to protect aquatic life and ensure the safety of aquaculture products. These findings provide a critical basis for policy-making, aimed at balancing agricultural productivity with environmental sustainability in regions heavily dependent on both.

Do typologies of pesticide risk knowledge influence the adoption of IPM strategies? Evidence from rice farmers' behavior in northern Iran.

The active participation of farmers in adopting eco-friendly practices is vital to mitigate the environmental and health risks linked to pesticide usage. Farmers' awareness of these risks significantly influences their adoption of integrated pest management (IPM) methods over traditional pesticide applications. This study sought to explore the range of understanding on pesticide effects, categorize IPM strategies employed in pest management, and examine the correlation between knowledge levels and IPM strategy choices. Data was gathered through structured questionnaires from 391 rice farmers in Sari County, Mazandaran province, Northern Iran. Exploratory factor analysis revealed three distinct dimensions of pesticide risk knowledge: personal risk of pesticide, environmental risk of pesticide, and community risk of pesticide. Furthermore, the study identified three primary categories of IPM strategies: high familiarity, intermediate familiarity, and low familiarity. The results of the regression analysis indicated that the personal risk of pesticides (β = 0.556; P < 0.01) and the environmental risk of pesticides (β = 0.262; P < 0.01) are significantly correlated with the adoption of high familiarity IPM strategies. Furthermore, the study revealed that there was no significant statistical evidence to support the notion that different types of pesticide risk knowledge had any influence on the adoption of intermediate and low familiarity strategies. The findings of this study imply the critical importance for agricultural extension programs to focus on enhancing farmers' knowledge of pesticide risks and various IPM strategies. © 2024 Society of Chemical Industry.

Pattern of Pesticide and Herbicide Poisoning Among People Admitted to Medicine Wards of a Tertiary Care Hospital

Introduction: Acute poisoning has become a major public health problem accounting for significant morbidity and mortality around the globe2. According to WHO data, an estimated 193,460 people died worldwide in 2012 from unintentional acute poisoning. 84% of these deaths occurred in resource-lacking low- and middle income countries3. The toxicity of accessible poisons and the scarcity of adequate medical facilities for poisoning management is responsible for a such a high mortality rate in this region4. Acute pesticide poisoning usually occurs during agricultural use either by accidental exposure or by suicidal attempt, rarely as homicidal2,5&amp;8. This study is designed to assess the patterns of pesticide &amp; herbicide poisoning among rural &amp; urban peoples admitted to medicine ward of a tertiary level hospital and to find out the sociodemographic characteristics of the respondents. So that the supply of these agents be properly regulated to prevent easy accessibility and misuse. Materials and Methods: It was a hospital based cross-sectional observational study conducted at indoor Department of Medicine, Chittagong Medical College Hospital for six months period from 01/01/2019 to 31/06/2019. Ethical clearance was taken from ethical review committee of Chittagong Medical College and informed consent was obtained from each participants. Hundred patients above 12 years of age with a relevant history and clinical signs and symptoms of any type of pesticides and herbicides poisoning who fulfilled the selection criteria were selected consecutively for the study. Data was collected using a pretested, multi-structured questionnaire which comprised of questions to identify demographic data, type and circumstances of poisoning. Results: Regarding motive of poisoning in our study 81% patient took pesticide &amp; herbicide poisoning for suicide and 19% admitted with accidental case. This result is consistent with the study where most common reason of pesticide &amp; herbicide poisoning was suicide (93.3%) 20. A study performed at Rajshahi Medical College from January 1991 to December 1994 showed that out of those 405 cases of OPC poisoning 310 were suicidal (76.54%) and 95 were homicidal (23.45%) poisoning28. The present study revealed that factors responsible for the suicidal attempt were familial disharmony in 46% of cases, marital problems in 19%, financial problem in 16%, mental disorder in 3% and 11% due to other reasons. Shadequl-Islam et al. reported the motive of pesticide poisoning in their study that 45% of cases were due to familial disharmony, 15% unknown, 13.3% depression, 8.3% marital problems, 5% financial problems and 13.3% due to other reasons26. In most cases, the patient could access to the poison by self-purchasing from poison retailers. Conclusion: This study has indicated that young adults, males and socially underprivileged people are at a higher risk of pesticides and herbicides poisoning. This study showed pesticides &amp; herbicides poisoning is the most common modes of suicidal deaths. Pesticides are mostly misused purposefully as an easy means for committing suicide. Early diagnosis and treatment is mandatory in order to minimize mortality from these potentially lethal compounds. It is recommended that the supply of pesticides be properly regulated to prevent easy accessibility and misuse. Medicine Today 2023 Vol.36 (1): 36-40

Occurrence, seasonal variations, and spatial distributions of current-use organoamine pesticides in the atmosphere of Shanghai, China

An increasing trend in pesticide usage requires a better understanding of the occurrence, fate, and exposure risk of current-use organoamine pesticides (CUOAPs) in the atmosphere as the population grows and climate changes. 33 target CUOAPs were measured in 89 atmospheric samples collected in different seasons from Shanghai, including gaseous and particulate phases. The total concentrations of gaseous phase CUOAPs ranged from 407 to 2980 pg/m3, with an average value of 887 ± 426 pg/m3. Conversely, the total concentrations of particulate CUOAPs were found to be one to two orders of magnitude lower than those in the gas phase, with low detection frequencies. Diphenylamine and Molinate were ubiquitous and predominant in the gaseous CUOAPs. The average total concentrations of gaseous CUOAPs were significantly higher in spring than those in winter and autumn seasons. Gaseous CUOAPs concentrations increased from rural to downtown areas during spring, showing different spatial distribution from winter and autumn. A significant correlation was observed between temperature and the presence of Dicloran, Pirimicarb, Diphenylamine, and Acetochlor. Agricultural activities and city pest control may be the main sources of CUOAPs, while meteorological factors including temperature and wind speed also impact the dispersal of these chemicals in the atmosphere. The increased risk of exposure was observed to be higher during the spring season compared to the autumn and winter seasons, aligning with the pattern of heightened utilization of CUOAPs during the planting and growing phases. The daily inhalation exposure of CUOAPs did not exceed the current oral reference dose.

Pesticide risk during commercial apple pollination is greater for honeybees than other managed and wild bees

Abstract Most pesticide research has focussed on risk to managed honeybees, but other managed and wild bees are also exposed to pesticides. Critically, we know little about the magnitude and sources of risk to honeybees compared with other bees during crop pollination. To compare pesticide exposure and risk across wild and managed bees, we sampled the main bee groups present during bloom in 20 apple orchards, including managed honeybees (Apis mellifera), managed bumblebee workers (Bombus impatiens), wild mining bees (Andrena spp. and Andrena [Melandrena] spp.), bumblebee foundress queens (Bombus impatiens) and eastern carpenter bees (Xylocopa virginica). We screened all bees for 92 pesticides and computed a Risk Quotient using available toxicity data (honeybee LD50s), adjusting for differences in toxicity known to scale with body mass. To gain insight into exposure origin, we compared residues in bees to those in focal orchard apple and dandelion flowers. Nearly all bee samples contained pesticides (95%), with the average contamination level ranging from 7.1 ± 2.8 parts per billion (ppb) in B. impatiens workers to 388.4 ± 146.2 ppb in Andrena. Exposure profiles were similar for all bees except A. mellifera, whose unique exposure profile included high levels of the neonicotinoid insecticide thiamethoxam. All bee groups except wild B. impatiens queens had at least one sample exceeding a US Environmental Protection Agency or European Food Safety Authority exposure level of concern. Apis mellifera experienced significantly greater risk than other bee groups, with 63% and 81% of samples exceeding an acute or chronic exposure level of concern, respectively. Risk to honeybees was driven primarily by high thiamethoxam levels not found in focal orchard flowers and likely originating outside the orchard. Synthesis and applications: We find that pesticide exposure and risk differ between honeybees and other managed and wild bees during apple pollination. Furthermore, pesticide exposure is a landscape‐scale phenomenon and therefore measures to reduce exposure must consider the surroundings beyond focal farms. Limiting orchard sprays, while reducing on‐farm exposures, will not protect far‐foraging bees from off‐farm exposures such as thiamethoxam, which we hypothesize is coming from nearby seed‐treated corn fields planted during apple bloom.

A new exposure protocol adapted for wild bees reveals species-specific impacts of the sulfoximine insecticide sulfoxaflor

Wild bees are crucial pollinators of flowering plants and concerns are rising about their decline associated with pesticide use. Interspecific variation in wild bee response to pesticide exposure is expected to be related to variation in their morphology, physiology, and ecology, though there are still important knowledge gaps in its understanding. Pesticide risk assessments have largely focussed on the Western honey bee sensitivity considering it protective enough for wild bees. Recently, guidelines for Bombus terrestris and Osmia bicornis testing have been developed but are not yet implemented at a global scale in pesticide risk assessments. Here, we developed and tested a new simplified method of pesticide exposure on wild bee species collected from the field in Belgium. Enough specimens of nine species survived in a laboratory setting and were exposed to oral and topical acute doses of a sulfoximine insecticide. Our results confirm significant variability among wild bee species. We show that Osmia cornuta is more sensitive to sulfoxaflor than B. terrestris, whereas Bombus hypnorum is less sensitive. We propose hypotheses on the mechanisms explaining interspecific variations in sensitivity to pesticides. Future pesticide risk assessments of wild bees will require further refinement of protocols for their controlled housing and exposure.

Modeling the implications of policy reforms on pesticide risk for Switzerland

Growing public awareness of the negative effects of pesticides on the environment, ecosystems, and human health has led governments to set targets for reducing pesticide risk. Switzerland introduced in 2023 two new policy measures to reduce pesticide risk by 50 % by 2027: (1) voluntary direct payment programs supporting pesticide-reduced and pesticide-free but non-organic cropping systems for most crops on arable land, and (2) restrictions of harmful pesticides for farmers managing under Swiss cross-compliance standards. This study aims to (1) develop a method to assess pesticide risk on a national scale and (2) carry out an ex-ante impact assessment to predict whether these policies can effectively reduce pesticide risks in Switzerland. Therefore, we introduced crop-specific pesticide quantities and pesticide risk scores into a sample of 1907 bio-economic farm optimization models. The models were used to predict farmers' adoption decisions regarding voluntary direct payment programs from 2019 to 2030. By combining the bio-economic farm optimization models with an agent-based modeling approach, we assessed the evolution of pesticide-related risks at the national level. Simulations for pesticide risk from 2019 to 2022 reflected the observed pesticide risk monitored by the Swiss government. In surface waters and semi-natural habitats, achieving the target depends on reducing pyrethroids, a class of insecticides with high-risk potential. Further, we highlight significant uncertainty in projecting the risk potential for surface waters and semi-natural habitats due to uncertainty about the amounts of pyrethroid used for different crops. The results underline the need for comprehensive datasets on pesticide use in Switzerland.