Pesticide Mixtures Research Articles

Histological and Enzymatic Changes of the Liver in Common Carp(Cyprinus carpio L. 1758) After Chronic Exposure to A Mixture of Goldate and Alexander Pesticides

Pesticides are man-made chemical compounds, widely used in agriculture to control different types of pests, product crops and prevent diseases which damage them. This experiment used herbicide Goldate, insecticide Alexander and their mixture with different concentrations exposed to common carp in 40L glass aquaria. The results showed that there was a significant increase in the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) means value of mixture pesticides compared with control. The liver tissues of the fish exposure to pesticides groups G1, A1, M1 and M2 showed different degrees of jaundice, cellular swelling, necrosis hepatocytes and vascular degeneration of pancreatic acini and aggregation of bile pigments. These effects increased with the increase in pesticides concentrations and exposure time. These effects also increased when exposure was to more than one pesticide at the same time. The study aimed to evaluate the effects of two pesticides as mixture, study the chronic toxicity of Goldate, Alexander and their mixture by assessing ALT, AST and liver histological changes. This study concluded that the Goldate + Alexander mixture had adverse effects more than each one alone.

Mixtures of serum concentrations of organochlorine pesticides and breastfeeding duration.

The relationship between breastfeeding duration and maternal mixtures of organochlorine pesticides (OCP) biological concentrations has not been documented. For that reason, our objective was to evaluate the association between lactation duration and mixtures of OCP serum concentrations and their principal metabolites, as well as to identify the primary contributors within these mixtures. Consequently, we conducted a secondary analysis of 878 women over 18years old who had at least one living child and served as controls in a population-based study from 2007 to 2011 in Northern Mexico. Through direct interviews, we collected data on breastfeeding duration, sociodemographic characteristics, and medical history. We determined serum concentrations of 24 OCP, including some metabolites, using gas chromatography with an electron microcapture detector. We applied Weighted Quantile Sum (WQS) regression models with binomial family specification to assess the relationship between breastfeeding duration (both for the first child and all children) and mixtures of OCP serum concentrations and their metabolites of interest. We identified a mixture of OCP negatively associated with breastfeeding the first child (OR = 0.63, 95% CI 0.52-0.77) and all children (OR = 0.59, 95% CI 0.46-0.75). The significant OCP or metabolites in both mixtures included p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), trans-nonachlor, β-hexachlorocyclohexane (β-HCH), p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), heptachlor, and hexachlorobenzene (HCB). Our results suggest serum concentrations of OCP mixtures in women who breastfed for at least 12months are lower than those who breastfed for less than that time. Future studies are needed to evaluate the risk-benefit of multiple OCP in breast milk for maternal and child health.

Biological Effectiveness of Tank Mixtures of Pesticides and Micronutrients in the Protection of Winter Wheat and Their Effect on Grain Yield and Quality

The effectiveness of protecting winter wheat from pests and diseases, yield and grain quality were studied by using tank mixtures of new pesticides and agrochemicals, mainly of domestic production. The study was conducted in small-scale experiments in the conditions of the forest-steppe of the Central Chernozem region in crops of winter soft wheat (Triticum aestivum L.) of the Krasa Dona variety. The size of plots in the experiments is 30 m2, the repeatability is fourfold, the placement of plots is randomized. Tank insectofungicidal mixtures of Sparring + Ace and Klonrin + Elatus Ace individually and in combination with micronutrient Biostim Zernovoy were studied. To control the insectofungicidal effect, a tank mixture of Vostorg + Ceriax Plus, studied earlier, was used. Application of insectofungal tank mixtures Sparring + Ace and Klonrin + Elatus Ace individually and with micro-fertilization of Biostim Zernovoy in winter soft wheat crops of the Krasa Dona variety provided high biological efficacy against a complex of pests and diseases. The insecticidal activity of tank mixtures was 96.5–100, fungicidal – 78.3–90.5%. Spraying of winter wheat with tank insectofungicidal mixtures individually and with micro-fertilization contributed to a significant increase in the yield of winter soft wheat. The largest grain yield increases of 12.9 and 13.6 c/ha were obtained in variants with Sparring + Ace + Biostim Zernovoy and Klonrin + Elatus Ace + Biostim Zernovoy combinations. The use of the studied tank mixtures individually and with micro-fertilization increased the quality of winter wheat grain: the content of crude gluten increased by 2.1–3.4% relative to the control, and its quality improved.

Pesticide residues in tropical agricultural soils: Distribution, seasonality, and earthworm ecological risk

Soil contamination by pesticide residues is associated with agricultural intensification in tropical regions and endangers human health and the environment. A mixture of pesticide residues and their degradation products persist in agricultural soils and represent a risk to soil organisms. In this study, we aimed to investigate the concentration and distribution of organochlorine (OC) and organophosphate (OP) pesticide residues in agricultural soils where the industrial cultivation of maize and soybeans is intensively carried out, at three depths (0–5, 5–15, and 15–30 cm) and during two seasons (rainy and dry). Likewise, we performed the ecological risk assessment of those found pesticide residues on two earthworm species, Eisena fetida, and Aporrectoda calagionsa. We calculated the Toxicity-Exposure Ratio (TER) using Predicted no Effect Concentrations (PNEC) and measured concentrations in soils, for identifying the risk of pesticide residues separately. The Risk Quotient (RQ) method was used to evaluate the ecological risk of pesticide residue mixtures in soils from each cropping system. Endrin ketone and dieldrin were the pesticide residues with the highest frequency of detection. The highest concentration in the study was found in a soil sample from maize crops in the dry season at 15–30 cm depth (2917 ng/g). The pesticide mixture from soil samples belonging to maize (0–5 cm) and soybean (5–15 cm) crops in dry season posed the highest ecological risk for A. caliginosa with 100 %, and a maximum RQ of 82.2. Endrin ketone is the OC that contributed most to the overall toxicity of the pesticide mixture in soil samples from maize crop and dieldrin in soil samples from soybean crop. Among OP, disulfoton contributed most to RQsite in soybean crop and methyl parathion in maize crop. Results pointed out the need to apply alternatives to remediate obsolete pesticide residues and restrict the use of methyl parathion and disulfoton in maize and soybean crops, to reduce the ecological risk that represent for earthworms.

Poisoning due to Spinosad in honey bees: toxicological report

The decline of honey bees is a global problem that affects beekeeping farms worldwide caused by several factors, such as pests, pathogen agents, intensive use of pesticides, etc. Although new classes of safer pesticides have been developed (pyrethrins and pyrethroids, neonicotinoids, pesticides of microbial origin, etc.), honey bees may be easily poisoned when they feed on contaminated nectar or pollen. This toxicological report describes a case of the poisoning of honey bees, Apis mellifera, due to the use of Spinosad, a natural insecticide of microbial origin found among other pesticides commonly used in agricultural practice, and underlines the severity of poisoning due to colony losses, with a significant presence of dead and dying adult bees. The clinical inspection conducted in the beekeeping farm admitted to exclude bee death due to various pathogen agents (parasites, fungi, and bacteria). Subsequently, the chromatographic analysis of pesticides, carried out on both honey bees and honeycomb samples, confirmed the presence of significant concentrations of Spinosad in bees (2.6 mg/kg), responsible for their poisoning, and in honeycomb (0.095 mg/kg), with residual levels > MRL, established by EU regulation for honey and honey bee products. This investigation underlines the high toxicity of Spinosad on A. mellifera, used often in pesticide mixtures or associations, and the risk for this pollinator species, used as a valid bioindicator of environmental pollution. For this reason, more specific Legislative Recommendations UE are needed on the use of Spinosad, particularly in binary and ternary pesticide associations, employed in agricultural practice, to protect honey bee safety and, at the same time, to prevent environmental pollution.

Dietary exposure to mixtures of chemicals in the first year of life and allergic and respiratory diseases up to 8 years in the French EDEN mother-child cohort

Exposure to environmental chemicals has been associated with higher risk of childhood allergies. This study aimed to examine the association between infant’s dietary exposure to mixtures of chemicals and allergic and respiratory multimorbidity in childhood.Dietary exposures were assessed at 8 and 12 months in 724 and 745 children of the EDEN cohort. Allergic and respiratory multimorbidity clusters were identified using latent class analyses. Associations between dietary exposure to mixtures of chemicals and allergic clusters were assessed by adjusted multinomial logistic regressions.At 8 months, higher exposure to a mixture of furans, trace elements, dioxins and PAHs was positively associated with the “asthma only” cluster, while moderate exposure to a mixture of PAHs, pesticides, PCBs and acrylamide was negatively associated with this cluster. A mixture of PCBs and BFRs was positively associated with the “multi-morbidity” cluster. Exposure to a mixture of pesticides and trace elements was positively associated with the “allergy without asthma” cluster. At 12-months, higher exposure to a mixture of trace elements and pesticides was positively associated with “multi-morbidity” cluster.The differences in findings between the two ages suggest the need for further studies to explore this critical window of chemical exposure and its impact on children's health.

CLAMity: Mixtures of agricultural pesticides as multiple stressors in a bivalve species

Pesticides play a vital role in ensuring global food security amid a growing global population; however, their movement away from application sites can pose significant risks to the health of non-target species. Pollution of freshwater is a key contributor to the high extinction rates of freshwater species, which often face exposure to a complex “cocktail” of pollutants simultaneously. A better understanding of pesticide interactions will enable more targeted policies and land management practices to mitigate environmental damage while ensuring food security. In this study, Corbicula fluminea (Asian clam) were exposed to binary pesticide mixtures commonly found in two rivers in the South of England. The exposures involved individual pesticides and mixtures at a concentration of 0.1μg/L per pesticide. Selected molecular markers were targeted and proved to be impacted by the timing and the pesticide mixture; an Integrated Biomarker Response (V2) value was also calculated. Our results show that both seasonality and the chemicals characteristics of the pesticides may significantly modulate their toxicity, both individually and in a mixture. When put into the context of catchment management this data combined with pesticide monitoring could improve estimating ecological risk. To the authors’ knowledge, this is the first study to assess the molecular responses of these mixtures in bivalve molluscs using the IBRv2 value following exposure to combined pesticides.

Chemical mixtures of mercury, PCBs, PFAS/PFOS, and pesticides in freshwater fish in the US and the risks they pose for fish consumption

Freshwater fish are important food sources that also pose risks to human and wildlife health because of the bioaccumulation of environmental chemicals in their tissues. Although most studies, fish consumption advisories, and regulations focus on individual contaminants, fish consumers are exposed to mixtures of chemicals, including legacy contaminants and contaminants of emerging concern, that can have combined effects. Chemicals of emerging concern represent one source of hazard, but legacy contaminants can still pose threats to fish consumers due to their persistence in the environment. We investigate the following questions: 1) Do different chemicals correlate with one another in fish tissue, and if so, how? 2) How do levels of different chemicals in fish tissue vary by time and location? and 3) How do observed chemical levels compare with risk-based screening levels? Using several national data sources established and maintained by the US Environmental Protection Agency (NRSA, NCCA-GL, GLENDA, and NLFTS), this study examines the co-occurrence of chemicals in freshwater fish in lakes, ponds, streams, and rivers in the US. We determine that organic contaminants correlate with one another, but generally not with mercury; organic chemicals have declined over time, but mercury has not; and fish concentrations of legacy contaminants-even those banned for decades-continue to exceed risk-based screening levels. Despite some successes in curtailing release of pollutants, some contaminants in fish tissue have not declined and legacy and emerging pollutants continue to pose risks to fish consumers in the US. Correlations between chemicals in fish tissue suggest that exposures to mixtures is prevalent in the US but that organic contaminants do not generally correlate with mercury-noteworthy particularly since fish consumption advisories in the US are frequently driven by the level of mercury, and do not account for exposure to multiple contaminants. While programs such as the National Aquatic Resource Surveys (NARS) Program seek to systematically monitor contaminants in fish tissue and other environmental indicators, continuous support from the US federal government is required to sustain this monitoring. Moreover, greater legislative and regulatory efforts are required at both the state and federal levels to reduce continuing sources and ongoing contamination.

Identifying childhood pesticide exposure trajectories and critical window associated with behavioral problems at 10 years of age: Findings from SMBCS

BackgroundPesticides may impact children’s neurodevelopment. As children’s metabolic function and neural plasticity change throughout their growth and development, the effects of pesticide exposure may also vary. ObjectivesWe aimed to identify the trajectories of combined pesticide exposure during childhood, and examine the associations of the exposure trajectories with children’s neurobehavior at the age of 10. MethodsWe involved repeated measurements of three pesticide metabolites [Pentachlorophenol (PCP), 3,5,6-Trichloro-2-pyridinol (TCPy), and Carbofuran phenol (CFP)], in urine samples collected from children in a cohort study at ages 1, 2, 3, 6, 7, 8, 9, and 10 years. The group-based multi-trajectory model (GBMT) and latent class analysis (LCA) were separately utilized to describe the distinct trajectories and patterns of pesticide mixture exposure during childhood. Meanwhile, the Strengths and Difficulties Questionnaire (SDQ) and attention deficit hyperactivity disorder (ADHD) Criteria of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) list were applied to assess behavioral disorders in children. The associations between exposure trajectories and behavioral problem scores were then examined. ResultsThe GBMT model delineated three distinct trajectories of combined pesticide exposure among children: consistently low, higher levels in early childhood transitioning to lower levels during pre-school age, and lower levels in early childhood followed by higher levels in the middle childhood. The LCA model identified three similar longitudinal exposure patterns. Further, the children in the second trajectory group identified by GBMT, characterized by higher early childhood exposure levels, exhibited significantly elevated hyperactivity/inattention scores of the SDQ compared to the other two groups (β = 0.46, 95 %CI: 0.11, 0.81; β = 0.44, 95 %CI: 0.02, 0.86). ConclusionsOur study revealed that exposure to pesticides during early childhood (especially before the age of two), rather than other age periods, was linked to hyperactivity/inattention problems in children aged 10 years. We also provided a novel perspective on characterizing the fluctuation in repeated measurements of multiple environmental chemicals and identifying the potential critical windows.

Unveiling six novel bacterial strains for fipronil and thiobencarb biodegradation: efficacy, metabolic pathways, and bioaugmentation potential in paddy soil.

Soil bacteria offer a promising approach to bioremediate pesticide contamination in agricultural ecosystems. This study investigated the potential of bacteria isolated from rice paddy soil for bioremediating fipronil and thiobencarb, common agricultural pesticides. Bacterial isolates capable of degrading fipronil and thiobencarb were enriched in a mineral salt medium. A response surface methodology with a Box-Behnken design was utilized to optimize pesticide degradation with the isolated bacteria. Bioaugmentation tests were performed in paddy soils with varying conditions. Six strains, including single isolates and their mixture, efficiently degraded these pesticides at high concentrations (up to 800 µg/mL). Enterobacter sp., Brucella sp. (alone and combined), and a mixture of Stenotrophomonas sp., Bordetella sp., and Citrobacter sp. effectively degraded fipronil and thiobencarb, respectively. Notably, a single Pseudomonas sp. strain degraded a mixture of both pesticides. Optimal degradation conditions were identified as a slightly acidic pH (6-7), moderate pesticide concentrations (20-50 µg/mL), and a specific inoculum size. Bioaugmentation assays in real-world paddy soils (sterile/non-sterile, varying moisture) demonstrated that these bacteria significantly increased degradation rates (up to 14.15-fold for fipronil and 5.13-fold for thiobencarb). The study identifies these novel bacterial strains as promising tools for bioremediation and bioaugmentation strategies to tackle fipronil and thiobencarb contamination in paddy ecosystems.

Aquatic hazard and risk posed by four pesticides detected in waterways discharging to the Great Barrier Reef, Australia: Part 2. Hazard and risk assessment

Pesticide active ingredients (PAIs) are regularly detected in the rivers, creeks, wetlands, and inshore waterways that discharge to the Great Barrier Reef (GBR) lagoon. Pesticide active ingredients detected above ecologically protective concentrations may pose a hazard and risk to aquatic species. The ability to assess this hazard and risk is reliant on the availability of water quality guidelines, which are only available for a limited number of PAIs detected in GBR catchment waterways. Unendorsed guideline values, known as ecotoxicity threshold values (ETVs) were developed in part one of this study for active ingredients in two fungicides (4-hydroxychlorothalonil (fungicide degradate) and carbendazim) and two insecticides (dimethoate and methoxyfenozide) that are commonly detected in GBR catchment waterways. In the current study, the hazard and risk posed by these PAIs was assessed by comparing the ETVs to environmental monitoring data from the Great Barrier Reef Catchment Loads Monitoring Program. Exceedances of the concentrations that should protect 99 % of aquatic species (i.e., PC99) were observed for all four pesticides. Detected concentrations of 4-hydroxychlorothalonil, carbendazim and methoxyfenozide exceeded the PC95 ETV, however no exceedances of the PC95 were observed for dimethoate. The hazard quotient (HQ) method was used to identify high hazard sites across the GBR catchment area. In total, six sites were identified as having concentrations that exceeded the PC95 ETVs. For 4-hydroxychlorothalonil, the risk to aquatic species based on the 95th percentile concentrations ranged from 3 to 13 %, 1 to 8 % for carbendazim and 2 to 8 % for methoxyfenozide. Detected concentrations of carbendazim were two orders of magnitude higher than concentrations that are reported to induce behavioural effects in some fish species. Considering that detected concentrations of three of the four PAIs individually pose a potential risk to aquatic species, their contributions to pesticide mixture toxicity should be further assessed.

Identifying pesticide mixtures at country-wide scale

Identifying pesticide mixtures at country-wide scale

First evidence of age-dependent decreases in non-persistent pesticide mixtures in nestlings of a farmland raptor

Intensive use of synthetic pesticides in conventional agriculture may harm non-target organisms through sublethal effects on life-history traits. Farmland birds are exposed throughout their life cycle, but the fate of non-persistent pesticide mixtures in wild birds remains unknown. In this study, we investigated changes in pesticide contamination levels in Montagu's harrier (Circus pygargus) nestlings during their growth. In total, 35 chicks were sampled twice during the rearing period, and blood was tested for 116 pesticides to assess pesticide load through two proxies; the number of pesticides detected and the sum of pesticide concentrations. Body mass and tarsus length were also measured to estimate body condition. Across the two sampling times, nine herbicides, five insecticides and four fungicides were detected. Contamination levels decreased significantly with nestling age irrespective of sampling date, and there was no relationship between pesticide load and body condition. Moreover, concentrations of chlorpyrifos-methyl, fenpropidin, metamitron, picloram and S-metolachlor, all detected throughout the rearing period, were unrelated to any of the explanatory variables. However, ethofumesate concentrations decreased significantly with chick age. This study provides the first evidence that non-persistent pesticide mixtures can decrease with age in wild nestlings. This has implications for understanding how chicks are contaminated and provides new insights on pesticide fate within organisms.

Comparative assessment of the nature of the combined action of insecticides: different methodical approaches

Introduction. Pesticide mixtures containing insecticide methomyl are commonly used in agriculture. However, the interaction of their active ingredients in a mixture has been insufficiently studied. The purpose of the study was to evaluate the nature of the combined action of a mixture of insecticides methomyl (carbamate) and bifenthrin (pyrethroid) using various methods: a classical model (orthogonal planning of the experiment using nonlinear variables); a generalized linear regression model for the binomial distribution (probit regression); and an isobologram. The study was conducted at the Federal Scientific Center of Hygiene named after F.F. Erisman of the Federal Service for Supervision in Protection of the Rights of Consumer and Man Wellbeing, according to the protocol approved by the local bioethical commission. Materials and methods. Ninety male outbred rats were administered 9 combined doses of the insecticides (combinations of LD16, LD33 and LD50 for the individual compounds, as devised from a preliminary study). Results. Impaired coordination, tremor of the limbs and head, turning into convulsions, rapid (shallow) breathing were observed in all groups. The data on mortality as used to construct 2 mathematical models, as well as to construct an isobologram. Limitations. The study was limited to studying the indicators of acute oral toxicity, without taking into account the possible repeated exposure. Conclusion. The models showed that the additive effect for the combination of methomyl and bifenthrin was only observed for combinations when the individual dose of bifenthrin was equal to or greater than 45 mg/kg b.w. (LD33) and the dose of methomyl was less than 30 mg/kg b.w., as all animals receiving a dose of 30 mg/kg b.w. of methomyl (LD50) in the mixture died. Therefore, the dose of methomyl dictated the toxic effect of the mixture, which should be accounted for in hygienic regulation of methomyl-containing formulations.

Associations of PFASs and Pesticides with Lung Function Changes from Adolescence to Young Adulthood in the ESPINA study.

Per- and polyfluoroalkyl substances (PFASs) and pesticides are ubiquitous environmental exposures with increasingly recognized adverse health outcomes; however, their impact on lung function, particularly in combination, remains poorly understood. We included 381 adolescent participants from a prospective cohort study in Ecuador who underwent measurements of serum PFAS (perfluorooctanoic acid [PFOA], perfluorooctanesulfonic acid [PFOS] and perfluorononanoic acid [PFNA]) and urinary herbicides (glyphosate, 2,4D) and fungicides (ethylene thiourea) and had spirometric measurements in either 2016 or 2022. We characterized the association between each PFAS or pesticide and each lung function measure in log-log models estimated via ordinary least squares regression. We used quantile g-computation to assess the association of the mixture of PFAS and pesticides with lung function outcomes. After accounting for multiple hypothesis testing, and in models adjusting for household income, parental education, and exposure to tobacco, we found that, individually, PFOA, glyphosate, and ETU were associated with slight increases in FEV1/FVC between 2016 and 2022. No other individual associations were significant. In mixtures analyses, a one quartile increase in all PFASs and pesticides simultaneously was also not associated with statistically significant changes in lung function outcomes after accounting for multiple hypothesis testing. In large part, we do not provide evidence for associations of PFAS and herbicide and fungicide pesticides with lung function among adolescents in moderate-to-high-altitude agricultural communities in Ecuador.

Comparative study of oxidative stress in cancer patients occupationally exposed to the mixture of pesticides.

Cancer isa leading cause of death worldwide, accounting for nearly 10 million deaths in 2020.Reviews indicated a positive relationship between exposure to pesticides and the development of cancers. In the present study, we have estimated the level of oxidative stress markers in serum samples of pesticide exposure and unexposed cancer patients as compared to normal control. We have found a significant decrease in peroxygenase (PON) and arylesterase (ARE) activity and substantial increases in homocysteine levels in both cancer groups. The level of heme biosynthesis rate-limiting enzymesdelta-aminolevulinic acid dehydratase(δ-ALA-D)also significantly decreased compared to control. The statistical comparison between the cancer groups does not show significant changes. We concluded the involvement of oxidative stress in carcinogenesis in both cancer group patients. However, more study is needed to put homocysteineas a novel marker for a variety of diseases on a single platform.

Toxic Effects of Imidacloprid, Copper Sulfate, and Their Combinations on Biomolecular and Oxidative/Antioxidant Biomarkers in the Tissues of Oreochromis niloticus.

The wide-ranging use of heavy metals and pesticides worldwide and their irreversible accumulation in aquatic ecosystems is a major concern. As the range of household and agricultural chemicals increases, water pollution is trending from the toxic effects of a single agent to complex agent pollution that threatens aquatic ecosystems. The aim of this study was to investigate the effects of pesticides (imidacloprid, IMI) and metals (copper sulfate, CuSO4) on oxidative stress biomarkers, antioxidant enzymes, and biomolecular parameters. The present study on the individual and combined effects of Oreochromis niloticus copper sulfate (CuSO4; 1ppm), imidacloprid (IMI; 10 and 50ppm), and IMI + CuSO4 (IMI10 + CuSO4, IMI50 + CuSO4) groups for 14days. In this context, oxidative stress/antioxidant markers (SOD, CAT, GST, and GSH) and biomolecular markers including HSP70, 8-OHdG, PC, and TBARS levels were examined in fish liver and kidney tissues, which are detoxification organs. The results indicated that IMI and CuSO4 toxicity alone and in combination altered oxidative stress/antioxidant markers and biomolecular parameters; moreover, 14days of exposure to the combination of CuSO4 and imidacloprid in particular exhibited a synergistic effect and caused oxidative toxicity. These findings highlighted the importance of evaluating mixtures of pesticides and metals and that the results show a remarkably synergistic effect. It can be concluded that these biomarkers are important indicators of physiological changes in living organisms.

Comparison of Combined Dissipation Behaviors and Dietary Risk Assessments of Thiamethoxam, Bifenthrin, Dinotefuran, and Their Mixtures in Tea.

In the tea-planting process, insecticides are commonly combined, potentially prolonging the pre-harvest interval and heightening the risk of dietary exposure. This study focused on three frequently used insecticides in tea cultivation: thiamethoxam, bifenthrin, and dinotefuran, aiming to investigate their dissipation behaviors and associated dietary risks upon individual and simultaneous application. The dissipation kinetics of thiamethoxam, bifenthrin, and dinotefuran were successfully characterized by first-order kinetics, yielding respective half-lives of 5.44, 9.81, and 10.16 days. Upon joint application, the dissipation half-lives of thiamethoxam and bifenthrin were notably prolonged compared with their individual applications, resulting in final concentrations after 28 days that were correspondingly elevated by 1.41 and 1.29 times. Assessment of the dietary intake risk revealed that the chronic and acute risk quotients associated with thiamethoxam and bifenthrin escalated by 1.44-1.59 times following their combined application. Although dietary risks associated with Tianmuhu white tea, as determined by the exposure assessment model, were deemed acceptable, the cumulative risks stemming from pesticide mixtures across various dietary sources warrant attention. Molecular docking analyses further unveiled that thiamethoxam and bifenthrin competitively bound to glutathione S-transferase (GST) at amino acid residues, notably at the 76th GLU and the 25th PHE, pivotal in the metabolism and absorption of exogenous substances. Moreover, the interactions between P-glycoprotein and pesticides during transport and absorption were likely to influence dissipation behaviors post-joint application. This research offers valuable insights and data support for optimizing joint pesticide application strategies and assessing risks associated with typical pesticides used in tea cultivation.

Eco(geno)toxicity of an acaricidal formulation containing chlorpyrifos, cypermethrin, and fenthion on different plant models and Artemia salina L.

The mixture of pesticides is widely employed in cattle farming to combat ectoparasite resistance, such as ticks. The commercial formulation COLOSSO FC30, which contains three active ingredients (Cypermethrin, Chlorpyrifos, and Fenthion), stands out due to its efficiency. However, animals exposed to this product may become vectors of potentially toxic molecules, possibly causing contamination in aquatic and terrestrial ecosystems. In light of this, this study evaluated the eco(geno)toxic potential of the commercial formulation COLOSSO FC30, using plants (Allium cepa L., Lactuca sativa L., Raphanus sativus L., Pennisetum glaucum L., and Triticum aestivum L.) and Artemia salina L. as model organisms. In the phytotoxicity test, the species were ranked in order of sensitivity to the commercial formulation as follows: P. glaucum > L. sativa > T. aestivum > R. sativus. The most sensitive parameters were root length (RL) and shoot length (SL) of seedlings. In the cytogenotoxicity test with A. cepa, cell division was decreased at concentrations from 0.351mL L-1 in the meristematic region and root F1. Chromosomal aberrations and micronucleus were observed at all concentrations. In the test with A. salina, the IC50 after 24h of exposure was 0.01207mL L-1 of the commercial formulation. The results highlight the need for further research and regulations to understand and minimize the potential environmental impacts of COLOSSO FC30.

Mixture effect of parental exposure to triazophos and fenvalerate on the early development of zebrafish offspring

Triazophos (TRI) and fenvalerate (FEN) have been extensively used in the world and frequently coexist in the water environments, might pose health risk to aquatic species. However, investigations of their mixture toxic effects on offspring after parental exposure have been neglected, especially for aquatic vertebrates such fish. To address this knowledge gap, parental zebrafish (F0 generation) were exposed to TRI, FEN and their mixture for 60 days, as well as the embryos (F1 generation) were hatched without or with continued corresponding exposures at the same concentrations until 7 days post fertilization. The results exhibited that exposure to TRI and FEN altered the expression levels of biomarkers associated with several biological processes, such as apoptosis and inflammatory response. Compared to individual exposure in the F1 generation, the co-exposure to TRI and FEN resulted in increased the expression of T4 and cc-chem mRNA and decreased the expression of ROS, trα, il-8, and gpx mRNA when the F0 generation was similarly exposed. These results revealed that the co-exposure to TRI and FEN has detrimental effects on fish progeny following parental exposure, even if the progeny are not directly exposed to the pesticides, and such negative effects may be intensified if the offspring continue to be exposed. This study enhances the understanding of the harmful impacts of parental exposure to the pesticide mixture on descendants and holds implications for the ecological risk assessment of pesticide mixtures in aquatic vertebrates. Further mechanistic studies are necessary to gain a deeper insight into the mixture effects of pesticides and other kinds of pollutants on subsequent offspring following parental exposure.