Hazardous Pesticides Research Articles

Recent advances in the toxicological effects of difenoconazole: A focus on toxic mechanisms in fish and mammals.

The toxicological study of pesticides at sub-lethal and environment-relevant concentrations has become increasingly crucial for human and environmental health. Toxic mechanisms of agrochemicals contribute to discovering green pesticides, assessing the hazards of pesticides comprehensively, and supporting legitimate regulatory decisions. However, the toxicological effects of difenoconazole are not yet fully understood despite being frequently detected in fruits, vegetables, waters, and soils and posing hazards to humans and the environment. This lack of knowledge could lead to flawed risk assessment and administrative oversight. Thus, the review aimed to provide some investigation perspectives for clarifying the toxicological effects of difenoconazole by synthesizing the toxic data of difenoconazole on various organisms, such as bees, Daphnia magna, fish, earthworms, mammals, and plants and summarizing the toxicological mechanisms of difenoconazole, especially in fish and mammals from peer-reviewed publications. Evidence revealed that difenoconazole caused multiple toxicological effects, including developmental toxicity, reproductive toxicity, endocrine disruption effects, neurotoxicity, and transgenerational toxicity. The toxic mechanisms involved in metabolic disturbance, oxidative stress, inflammation, apoptosis, and autophagy by activating reactive oxygen species-mediated signaling pathways and mitochondrial apoptosis routes, disturbing amino acids, lipid, and nucleotide metabolism, and regulating gene transcription and expression in mammals and fish. Based on the review, further studies better focus on the toxic differences of difenoconazole stereoisomers, the toxicological effects of transformation products of difenoconazole, and the mechanism of action of difenoconazole on sex-specific endocrine disruption effects, intestinal damage, and gut dysbacteriosis for its hazard assessment and management synthetically.

Environmental Detoxification of Benzimidazole Fungicide Fuberidazole via Microbial Action in Liquid Cultures

Mitigation of the environment from hazardous pesticides is clamant for all living things. The behavior of the fungicide Fuberidazole was investigated toward biodegradation. Biotransformation experiments were conducted by bacterial strains isolated from soils including, Xanthomonas citri (XC), and Pseudomonas syringae (PS), and fungal strains including, Aspergillus flavus (AF), Aspergillus niger (AN) and Penicillium chrysogenum (PC). Analysis and quantification of Fuberidazole degradation and its metabolites were performed by gas chromatography mass spectrometry and UV-visible spectrophotometry. Pseudomonas syringae and Penicillium chrysogenum displayed great bioremedial potential and degraded 91 and 86% of Fuberidazole after 35 days. Significant metabolites such as Benzimidazole 2-carboxylic acid, Benzimidazole, and 1-(1H-benzimidazole-2-yl)ethanone were produced in the current experiment. The increasing order of half-life for all strains was obtained as, PS (10.3) < PC (10.6) < AN (11) < AF (11.9) = XC (11.9) days. Experimental results demonstrated the capability of bacterial cells to efficiently utilize Fuberidazole as a nutrition source and the significance of favorable environmental conditions for its dissipation.

Assessment of unintentional acute pesticide poisoning among smallholder vegetable farmers in Trinidad and Jamaica

Poisoning caused by pesticides is widely recognized as a major public health problem among smallholder farmers and rural communities, including in the Caribbean. However, a lack of quality data impedes understanding of the problem and hampers the development of effective strategies for its management. To better understand the prevalence of unintentional acute pesticide poisoning (UAPP) in Trinidad and Tobago and Jamaica and the pesticides and practices involved, we conducted a cross-sectional survey of 197 and 330 vegetable farmers in Trinidad and Jamaica, respectively. The findings from this study revealed a high incidence of self-reported health effects from occupational pesticide exposure, with 48 and 16% of respondents, respectively, experiencing symptoms of UAPP within the previous 12 months. Furthermore, the substantial proportion of UAPP incidents were associated with a few highly hazardous pesticides (HHPs), particularly lambda-cyhalothrin, acetamiprid, and profenofos in Jamaica, and alpha-cypermethrin, paraquat and lambda-cyhalothrin in Trinidad. Given the well-documented adverse effects of these chemicals on human health, the results of this study should be of significant concern to health authorities in Jamaica and Trinidad. This clearly indicates an urgent need for improved regulation and safer alternatives to the use of HHPs, as well as the promotion of alternatives. We provide policy recommendations and identify alternatives to HHPs for tropical vegetable production.

Nb(V)-containing saponite: A versatile clay for the catalytic degradation of the hazardous organophosphorus pesticide paraoxon under very mild conditions

A synthetic saponite clay containing structural Nb(V) metal centres (NbSAP) was investigated in the abatement of paraoxon-ethyl, an anti-cholinergic organophosphorus pesticide, under mild conditions (neutral pH, room temperature and ambient pressure) in heterogenous phase, without additional basic additives. The material was selected according to its high surface acidity and ease of preparation through a one-step hydrothermal synthesis. The presence of Nb(V) ions played a crucial role in efficiently catalysing the degradation of aggressive chemical substrates. A niobium(V) oxide with very low surface acidity was also tested as a reference material. The study employed a multi-technique approach to monitor the pesticide degradation pathway and by-products formed during abatement experiments in polar non-protic and aqueous solvents. Notably, in water, the concentration of paraoxon-ethyl significantly decreased by 82 % within the first hour of contact with the clay. Additionally, NbSAP demonstrated a good performance after three repeated catalytic cycles and subsequent reactivation.

Bacillus thuringiensis Cry14A family proteins as novel anthelmintics against gastrointestinal nematode parasites.

Bacillus thuringiensis crystal (Cry) proteins have been expressed in commercial transgenic crops for nearly 30 years, providing safe and effective control of insect pests and significantly reducing the application of hazardous chemical pesticides. B. thuringiensis crystal proteins have also been shown to target parasitic nematodes, including plant parasitic nematodes. Recently, transgenic soybean crops expressing Cry14Ab have been shown to provide control against the soybean cyst nematode Heterodera glycines, marking the first time a crystal protein is being commercialized in transgenic crops for control of a nematode pest. However, apart from H. glycines and the free-living nematode, Caenornabditis elegans, the breadth of nematode activity of Cry14Ab, e.g., against gastrointestinal parasitic nematodes (GINs), has not been reported. Here we study the efficacy of Cry14Ab against a wide range of gastrointestinal nematode parasites (GINs) in vitro and in vivo. We find that Cry14Ab is effective in vitro against the barber's pole worm Haemonchus contortus larvae, small strongyles cyathostomin larvae, the hookworm Ancylostoma ceylanicum adults, the roundworm Ascaris suum L4 larvae, and the whipworm Trichuris muris adults. In rodents infected with GIN parasites, Cry14Ab is effective as an in vivo anthelmintic against the hookworms A. ceylanicum and N. americanus, against the mouse parasite Heligmosomoides polygyrus bakeri, and against the roundworm A. suum. Cry14Ab also variably reduces the reproduction of the whipworm T. muris in vivo. Using optimized profile Markov Models, we looked for other putative anthelmintic Cry proteins and, within this list, identified a Bt crystal protein, GenBank accession no. MF893203, that we produced and demonstrated intoxicated GINs. This protein, with 90% amino acid identity to Cry14Ab, is active against C. elegans, A. ceylanicum adults, and A. suum L4 larvae in vitro. MF893203 was given the official designation of Cry14Ac. Cry14Ac is also an effective in vivo anthelmintic against A. ceylanicum hookworms in hamsters and intestinal A. suum in mice. Taken together, our results demonstrate that Cry14Ab and Cry14Ac have wide therapeutic utility against GINs.

Plasmonic Nanocubes with a Controllable "Crescent Arc" Facet: Tunable Hotspot Engineering for Highly Reliable and Sensitive SERS Detection.

The fine control of the nanogap and morphology of metal nanoparticles (NPs) has always been an obstacle, hindering the development and application of surface-enhanced Raman scattering (SERS) quantitative detection. Here, Au/4-mercaptobenzoic acid@Ag@Au-Ag bimetal core-shell nanocubes (NCs) with a "crescent arc" facet (C-Au/4MBA@Ag NCs) as a highly reliable and sensitive surface-enhanced Raman scattering SERS substrate is proposed for the first time. The bifunctional internal standard (IS) molecules (4MBA) govern the morphology of metal shells to maintain cubic configuration and provide calibration for SERS signals' flotation. In parallel, the controllable curvature of the C-Au/4MBA@Ag NCs is directly modulated by adjusting the relative rates of the galvanic replacement and co-reduction reaction, which generates a controllable interparticle nanogap to offer large depositing spaces for analytes and improve authoritative SERS signals' enhancement. The proposed C-Au/4MBA@Ag NCs exhibit an enhancement factor of up to 4.8 × 1010 and contribute to the ultralow RSD (7.9%). These C-Au/4MBA@Ag NCs also enable the detection of hazardous pesticide residues such as methamidophos and thiram in herbal plants with a complex matrix, with an average detection accuracy of up to 96%. In summary, this study achieves a fine control strategy of the "crescent arc" surface for improving SERS performance and explores the practical application potential for accurate and sensitive Raman detection of hazardous substances.

Flexible SERS chips for rapid on-site detection of tricyclazole pesticide in agricultural products.

A flexible, ultrasensitive, and practical SERS chip is presented based on a paper/f-TiO2/Ag structure. The chip enhances the self-assembly of Ag nanoparticles on a cellulose fiber matrix, facilitated by smart functionalized TiO2 nanomaterials (f-TiO2). This design enables superior detection of the hazardous pesticide tricyclazole (TCZ) on crops using an advanced, simple, and efficient analytical method.Despite its straightforward fabrication process via a solvent immersion method, the intrinsic smart surface properties of the TiO2 bridging material -both hydrophilic and hydrophobic-enable the uniform and dense self-assembly of hydrophilic Ag nanoparticles (NPs) on the cellulose fiber paper substrate. This innovative design provides superior sensing efficiency for TCZ molecules with a detection limit reaching 2.1 × 10-9M, a remarkable improvement compared to Paper/Ag substrates lacking f-TiO2 nanomaterials, which register at 10-5M. This flexible SERS substrate also exhibits very high reliability as indicated by its excellent reproducibility and repeatability with relative standard deviations (RSD) of only 5.93% and 4.73%, respectively. Characterized by flexibility and a water-attractive yet non-soluble surface, the flexible Paper/f-TiO2/Ag chips offer the convenience of direct immersion into the analytical sample, facilitating seamless target molecule collection while circumventing interference signals. Termed the "dip and dry" technique, its advantages in field analysis are indisputable, boasting in situ deployment, simplicity, and high efficiency, while minimizing interference signals to negligible levels. Through the application of this advanced technique, we have successfully detected TCZ in two high-value crops, ST25 rice and dragon fruit, achieving excellent recovery values ranging from 90 to 128%. This underscores its immense potential in ensuring food quality and safety. As a proof of concept, flexible Paper/f-TiO2/Ag SERS chips, with a simple fabrication process, advanced analytical technique, and superior sensing efficiency, bring SERS one step closer to field applications beyond the laboratory.

Characterization of SrMoO4 synthesized at different temperatures and its photocatalytic performance toward Carbendazim fungicide degradation under UV light

The Scheelite SrMoO4 synthesized by co-precipitation, non-calcined and calcined at different temperature (500 – 800 °C) has been characterized physically and photoelectrochemically. The XRD analysis showed the formation of single phase at room temperature (SMO), crystallizing in a tetragonal structure and the oxide is thermally stable after calcination at 500 °C (SMO5) and 800 °C (SMO8). The crystallites size (D) increases with increasing thee calcination temperature (TC). The Raman spectra presents the characteristic vibrations of the tetragonal structure. Although its low temperature (TC), the specific surface area calculated by the BET method for SMO is weak (4.61 m2 g−1). The SEM images showed the effect of the temperature TC on the morphology of SrMoO4 and as expected the grain size increases with increasing TC. Diffuse reflectance showed a wide optical gap (4.26 eV) for SMO, in accordance with its white color and decreases only slightly (4.10 eV) with increasing TC. The points of zero charge (PZC) calculated by the Drift method for SMO, SMO5 and SMO8 are 5.92, 6.13 and 6.70 respectively. The photocatalytic properties of the powders were assessed through the degradation of Carbendazim (MBC), a hazardous and persistent pesticide, under UV irradiation (λmax = 365 nm). The degradation reached an abatement of 96 % after 15 min under optimal conditions ([SMO] = 0.8 g/L, [MBC] = 8 mg/L, at room temperature and natural pH 5.7) and increasing TC, reduces the degradation capacity of SrMoO4. The oxidation mechanism was elucidated by using scavengers and liquid chromatography (LC-MS/ESI) which showed that the holes (h+) and •OH radicals are responsible for the MBC degradation. The Total Organic Carbon (TOC) reached 70 % for the same period.

Development and assessment of vanadium-based metal–organic frameworks for the effective elimination of hazardous pesticides from aqueous solutions: Mechanism of uptake, adsorption capacities, rate of uptake, and enhancement via the Box-Behnken design

Vanadium metal–organic frameworks (V-MOF) has a great potential to remove contaminants from water that come from agriculture wastewater methyl parathion (MP) pesticides with high effectiveness. Using a variety of methods, such as SEM, FT-IR, XPS), XRD, and BET analysis, the adsorbent was successfully synthesized and characterized. The dimensions of the pores measured at 1.33 nm correspond to the classification of micropores under the IUPAC system. Before the adsorption process, the material had a surface area of 1489.42 m2/g and a pore volume of 0.98 cc/g. After MP adsorption, the surface area, pore size, and pore volume decreased to 1268.42 m2/g, 1.12 nm, and 0.64 cc/g, respectively. Changes in the material’s physical properties indicate that the adsorption process had an effect. 7.2 was the result of controlling the point of zero charge through surface characterization. This information suggests that the surface of the adsorbent has a positive charge at pH below 7.2 and at the pH higher than this value the surface will have a negative charge. It was also looked into how pH affected the adsorption equilibrium. Although fitting to Langmuir isothermally, the kinetics of MP adsorption onto V-MOF are pseudo-second-order fitting. It is very probable that chemisorption was the mode of adsorption because the adsorption energy was 23.62 kJ.mol−1. The enthalpy (ΔHo) values obtained as a result of studying the thermodynamic parameters are positive, demonstrating that, within this temperature range, the pesticide adsorption process was endothermic., measuring 32.79 kJ.mol−1. Entropy (ΔSo) readings that are positive indicate that the system’s randomness increased during the adsorption process, reaching 119 J.mol−1K−1, and with rising temperatures, the negative of ΔGo rise. The effectiveness of the recommended adsorbent was evaluated by filtering wastewater samples in a laboratory environment. It is hypothesized that V-MOF and MP will interact by pore filling, π-π interaction, H-bonding, electrostatic contact, and other possible methods. Considering the specifics of this interaction in great detail is essential to comprehending the nature of adsorption and effectively constructing the adsorbent for use in real-world applications. Water filtering and the treatment of industrial effluents were made simple and effective by the use of V-MOF adsorbent technology. The results indicated that 383.6 mg/g was the maximal adsorption capacity at pH = 6. To evaluate the renewal of the adsorbent, more tests were carried out, and the outcomes showed that the renewal continued even after more than six cycles. The stability of the adsorbent during regeneration was confirmed by using XRD and FT-IR. The Box Behnken design (BBD) was then employed to optimize the adsorption outcomes.

Selected farm-level crop protection practices in Europe and Argentina: Opportunities for moving toward sustainable use of pesticides

Extensive use of plant protection products (PPP) in the last decades contributes to negative impacts on ecosystems, animals and humans. For the strategies of PPP reduction and replacement of hazardous pesticides, farm-level data on agronomic management practices and crop protection applications are crucial. In this study, we strategically collected data for the 2021 season at the SPRINT project case study sites (CSS) in 10 European countries and Argentina, on perennial, arable and vegetable crops. Data collection included strategically selected farm and field data, pesticide records and farming practices. Results involved more than 1700 recorded PPP applications across various crops with more than 170 different active substances from PPP in organic, integrated pest management and conventional farming practices. We explored differences in application patterns (fungicides, insecticides, herbicides and non-PPP, e.g. adjuvants, growth regulators, and fertilizers) between and within crops, countries and farming systems and calculated the costs of PPP use. The pesticide dosages applied during the crop season varied up to a factor of 20 around recommended doses. Regarding the costs of PPPs use perennial crops had the highest costs per ha crop production area. Finally, we analysed the active substances applied in different farming systems in terms of their hazard statements. Our results shed light on how PPPs are used across different crop and farming types and will help elucidate how pesticide application patterns can be changed in the future. Finally, we highlighted non-PPP use practices which help to reduce dependency on PPP use. This might be used to support decision-making and policies within agricultural advisory/support systems.

Suppression of Thrips palmi population by spray-on application of dsRNA targeting V-ATPase-B

The RNA interference (RNAi)-based gene silencing technique has enormous potential as a non-chemical and eco-friendly alternative to hazardous pesticides. This study reports a spray-induced gene silencing (SIGS) approach for managing Thrips palmi by lowering survival and offspring development. Vacuolar ATP synthases (V-ATPases) are responsible for survival, egg-laying, and viability of eggs in insects. In the current study, T. palmi V-ATPase-B was targeted to suppress the pest population by spray-on application of double-stranded RNA (dsRNA). Silencing of V-ATPase-B was first validated by oral administration of dsV-ATPase-B. The expression of V-ATPase-B was reduced by 5.40-fold post-dsRNA feeding leading to increased mortality (57.03 %) and reduced reproductive fitness (67.73 %). Spray-on application of naked dsV-ATPase-B at concentrations of 3.0 μg/mL and 5.0 μg/mL effectively suppressed the population by 30.00 % and 43.33 %, respectively. The expression of the target gene was downregulated by up to 4.24-fold. Two consecutive sprays at a concentration of 5.0 μg/mL provided substantial protection against the fresh release of T. palmi for up to 10 days. The spray-on application of dsV-ATPase-B would be an eco-friendly alternative for managing T. palmi populations thereby reducing crop damage and limiting the spread of orthotospoviruses.

Rational design of Boerhavia diffusa derived CoFe2O4-Carbon dots@Boehmite platform for photocatalysis and ultra trace monitoring of hazardous pesticide and UO22+ ions

In view of exploiting natural resources for designing of effectual materials in favor of detection and obliteration of water pollutants, a fluorescent nanomaterial (CDBHCF) based on biomass derived carbon dots (CDs) was constructed. The CDs and cobalt ferrite (CF) particles were anchored on boehmite (BH) which served as a support material for CDs. The CDBHCF nanocomposite was prepared via facile hydrothermal treatment for selective recognition of Methyl parathion (MP) pesticide and uranyl ions (UO22+). The corresponding structural, morphological and opto-electronic properties of the nanomaterials have been investigated by different physicochemical techniques. The fluorescent CDBHCF probe was employed to detect extremely low concentration of MP and UO22+ with detection limit of 22.4 nM and 4.4 nM, respectively. Ultimately, the proposed sensing platform was validated through real sample analysis. Besides, CDBHCF nanocomposite was utilized for photocatalytic abolition of Tetracycline (TC) in water samples. Initially, the impact of various operational parameters on the degradation efficiency, including catalyst dosage and initial pH were thoroughly examined. Under optimized conditions, the fabricated CDBHCF nanocomposite demonstrated excellent results for photocatalytic degradation of TC (92 % degradation in 120 min) under visible light illumination. Thus, the proposed strategy delivered an innovative insight for dual purpose of CDBHCF nanocomposite: as a fluorescent probe for real time monitoring and as a photocatalyst for removal of pollutants via simple photocatalytic degradation.

Is Farming a Risk Occupation for Cardio-cerebrovascular Diseases? A Scoping Review on Cardio-cerebrovascular Disease Risk in Farmers.

In the Republic of Korea, cardiocerebrovascular disease (CCVD) is recognized as an occupational disease when sufficient evidence of a work-related burden exists. In 2021, approximately 26.8% of the payments from occupational disease insurance under the Industrial Accident Compensation Insurance Act were allocated to CCVDs. However, due to the specific nature of insurance policies for farmers, CCVD is not acknowledged as an occupational disease in their case. We reviewed studies on the differences in the incidence, prevalence, and mortality rates of CCVDs between farmers and the general population or other occupations and described the exposure of farmers to risk factors for CCVDs. Several studies showed that farming is a high-risk occupation for CCVDs, with the following risk factors: long working hours, night work, lack of holidays, and strenuous physical labor; physical factors (noise, cold, heat, humidity, and vibration); exposure to hazardous gases (diesel exhaust, carbon monoxide, hydrogen sulfide, carbon disulfide, nitrogen oxides, and polycyclic aromatic hydrocarbons), pesticides, and dust (particulate matter, silica, and organic dust); exposure to a hypoxic environment; and job-related stress. Social isolation and lack of accessible medical facilities also function as additional risk factors by preventing farmers from receiving early interventions. Farmers are exposed to various risk factors for CCVDs and are an occupation at risk for CCVDs. More studies are needed in the future to elucidate this relationship. This study lays the groundwork for future research to develop guidelines for approving CCVDs as occupational diseases among farmers.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Novel ZnIn2S4/Co(acac)2: An inorganic-organic hybrid nanocomposite for enhanced removal of imidacloprid from aqueous phase

Herein, the synthesis and application of an entirely novel ZnIn2S4/Co(acac)2 (ZIS-Co-2) nanocomposite for degradation of hazardous pesticide imidacloprid (IMD) under visible-light irradiation has been investigated. The ZIS-Co-2 nanocomposite demonstrated an outstanding 97.43 ± 1.84 % removal effectiveness against IMD within 60 min of 23 W LED. This improved catalytic performance was attributable to synergistic effects from ZnIn2S4 doping, which significantly delayed charge recombination and boosted visible-light absorption, promoting efficient photocatalytic degradation. Furthermore, the degradation of IMD was thoroughly verified using chemical oxygen demand (COD), and the total organic carbon (TOC) removal and breakdown mechanism was elucidated using liquid chromatography-mass spectrometry (LC-MS). Notably, the ZIS-Co-2 nanocomposite revealed outstanding recyclability, preserving catalytic activity for up to six cycles and the ability to degrade other emerging contaminants. Furthermore, neither Co(acac)2 nor the combination of ZnIn2S4 with metal complexes has been previously produced or explored for visible light-active photocatalytic applications, highlighting the originality of our study. Overall, the ZIS-Co-2 nanocomposite is a promising and sustainable solution for efficiently removing IMD and other environmental pollutants, with significant practical implications in wastewater treatment and environmental restoration.

Nickel cerium oxide-modified disposable and portable sensor for the rapid monitoring environmentally hazardous organophosphate pesticide in water and vegetable samples

The main novelty of this developed method is the detection of the hazard organophosphate pesticide fenitrothion (FNT) in real samples using a nickel cerium oxide (NiCeO) bimetallic oxide for electrocatalytic sensing in pond water, lake water, and various food samples such as brinjal, and bitter gourd. Extensive analytical and electrocatalytic assessments revealed that the NiCeO combination significantly improves electron transportation and augments the creation of electroactive sites. The resulting sensor exhibited remarkable performance characteristics, including a low detection limit, a wide linear range, and high sensitivity to FNT under pH-optimized electrocatalytic conditions, with values of ca. 1.8 nM, ca. 1–5747.3 μM, and ca. 104.383 (±0.002) μA μM−1 cm−2, respectively. Moreover, the NiCeO sensor demonstrated excellent recovery rates in real-world samples. The overall outstanding performance of the fabricated sensor indicates its excellent ability for real-time monitoring of FNT in ecological system.

Honey bee larval toxicity study designs: Applicability of the current study protocols and endpoints asa predictor of pesticide hazard for pollinators.

The assessment of pesticide risks to bees in North America currently relies in part on Tier 1 honey bee laboratory toxicity studies to support the registration and registration review processes for crop protection chemicals. For immature stages, the studies follow two standardized test designs recommended by the Organization for Economic Cooperation (OECD), evaluating acute (seven-day single-dose, TG OECD 237) and chronic (22-day repeated-dose, GD OECD 239) toxicity in bee larvae. In this article, we aim to evaluate the current approach for generating and interpreting honey bee larval toxicity data, enhancing pesticide risk assessment for pollinators. First, by considering that the repeated-dose larval study covers all stages of honey bee brood development up to adult emergence, we compared endpoints (larval LD/ED50 and LC/EC50 values) from seven-day acute exposure studies with the 22-day chronic exposure studies. Our goal was to identify the study design offering greater sensitivity in assessing pesticide toxicity to immature bees. Our second objective involved analyzing available weight data from emerged adults and comparing it to survival endpoints (e.g., NOEL and LD50) to determine if the weight after adult emergence would accurately represent a sensitive indicator of pesticide effects on developing honey bees. Our analysis determined that the use of a single 22-day chronic exposure study adequately covers all immature stages and that the toxicity values based on cumulative dose are more accurate and representative measures of exposure for immature bees than using endpoints based on estimated daily doses. Furthermore, our analysis suggests that measuring the weight of emerged adults was a more sensitive indicator than mortality of treatment-related effects in 22% of the compounds included in our analysis. Here we also discuss the importance of standardized protocols for proper collection of weight after emergence and the need for further discussion on the relevance of this parameter at risk assessment scheme. Integr Environ Assess Manag 2024;20:2283-2293. © 2024 Pollinator Research Task Force. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Restrictions on Pesticides and Deliberate Self-Poisoning in Sri Lanka

Deliberate self-poisoning using pesticides as a means of suicide is an important public health problem in low- and middle-income countries. Three highly toxic pesticides-dimethoate, fenthion, and paraquat-were removed from the market in Sri Lanka between 2008 and 2011. In 2015, less toxic pesticides (chlorpyrifos, glyphosate, carbofuran, and carbaryl) were restricted. Subsequent outcomes have not been well described. To explore the association of pesticide bans with pesticide self-poisonings and in-hospital deaths. In this cross-sectional study with an interrupted time series design, data were prospectively collected on all patients with deliberate self-poisonings presenting to 10 Sri Lankan hospitals between March 31, 2002, and December 31, 2019, and analyzed by aggregated types of poisoning. The correlates of pesticide bans were estimated within the pesticide group and on self-poisonings within other substance groups. The data analysis was performed between April 1, 2002, and December 31, 2019. Implementation of 2 sets of pesticide bans. The main outcomes were changes in hospital presentations and in-hospital deaths related to pesticide self-poisoning as measured using segmented Poisson regression. A total of 79 780 patients (median [IQR] age, 24 [18-34] years; 50.1% male) with self-poisoning from all causes were admitted to the study hospitals, with 29 389 poisonings (36.8%) due to pesticides. A total of 2859 patients died, 2084 (72.9%) of whom had ingested a pesticide. The first restrictions that targeted acutely toxic, highly hazardous pesticides were associated with an abrupt and sustained decline of the proportion of poisonings with pesticides (rate ratio [RR], 0.85; 95% CI, 0.78-0.92) over the study period and increases in poisonings with medications (RR, 1.11; 95% CI, 1.02-1.21) and household and industrial chemicals (RR, 1.20; 95% CI, 1.05-1.36). The overall case fatality of pesticides significantly decreased (RR, 0.33; 95% CI, 0.26-0.42) following the implementation of the 2008 to 2011 restrictions of highly hazardous pesticides. Following the 2015 restrictions of low-toxicity pesticides, hospitalizations were unchanged, and the number of deaths increased (RR, 1.98; 95% CI, 1.39-2.83). These findings support the restriction of acutely toxic pesticides in resource-poor countries to help reduce hospitalization for and deaths from deliberate self-poisonings and caution against arbitrary bans of less toxic pesticides while more toxic pesticides remain available.

Novel electrochemiluminescence sensing platform for ultrasensitive detection of malathion residue in tea based on SiO2NSs doped Luminol/AgNPs as a signal amplification strategy

To address the potential hazards of organophosphorus pesticides (OPs) residues in tea, an electrochemiluminescence (ECL) aptasensor based on functionalized nanomaterials was constructed in this work. Firstly, gold nanoparticles (AuNPs) were attached on the surface of multi-walled carbon nanotubes (MWCNTs) by the constant potential electrodeposition to form a compound, and it was utilized to provide excellent immobilization sites for complementary DNA (cDNA). Subsequently, composite nanomaterials were synthesized by a one-pot method with aminated Luminol/silver nanoparticles@silica nanospheres (NH2-Luminol/Ag@SiO2NSs). Finally, NH2-Luminol/Ag@SiO2NSs was combined with a malathion aptamer (Apt) to obtain signal probes (SPs) for the construction of an aptasensor. The aptasensor had a wide linear range (1×10−3-1×103 ng/mL) and a low limit of detection (LOD) (0.3×10−3 ng/mL). It had the virtues of high sensitivity, wonderful stability and excellent specificity, which could be used for the detection of malathion residue in tea. The work provides a proven way for the construction of a rapid and ultrasensitive aptasensor with low-cost.

"Ad hoc policy decisions" in the news: Media framing analysis of a pesticide import ban in Sri Lanka.

Modern agriculture relies on pesticides to maximise outputs. While many highly hazardous pesticides (HHPs) are banned in places like the European Union due to concerns about harm to the environment and human health, their use continues in many low- and middle-income counties (LMICs). Pesticide suicide is a public health problem unique to countries where HHPs are used, and Sri Lanka has successfully implemented several HHP bans as part of a suicide prevention strategy. On 27 April 2021, the Sri Lankan government announced an imminent import ban of all fertilizers and pesticides which was later revoked in November 2021. The aim of this article was to explore the media framing of the import ban as it pertained to pesticides. Guided by Entman's typology of frame functions, we analysed newspaper articles from nine Sri Lankan newspapers (N = 102) between 20 April to 31 October 2021. Overall, most framings were supportive of the ban, captured by framings that articulated the ban through a health, environment, and organic farming narrative. Framings that foregrounded farmer or industry livelihoods and the pesticide market were primarily adopted to express opposition to the ban. The presence of frames opposing the ban within media articles increased over time during the study period. There was a greater proportion of opposing frames in private newspapers compared to government (78% vs 22%). Many of the articles analysed described the widespread impact of the ban, but only 11% of articles represented the voices of policy end users. This study adds understanding to the ways communication via outlets like mainstream newspapers may shape public support or opposition to pesticide bans in a LMIC. Mass media is an under-recognised factor in policy implementation and this study may inform planning to implement pesticide bans in other countries.