Bioaccumulation of pesticides in fish resulting toxicities in humans through food chain and forensic aspects

Ecotoxicological impact of the fungicide tebuconazole on fish: a historical review, global trends and challenges

Tebuconazole (TBZ) is a triazole fungicide broadly used to control fungal diseases in agricultural crops, fruit-bearing plants and forestry plantations. However, its increasing use and release into aquatic environments has raised concerns about its hazardous effects on the health of fish. Thus, the aim of the present study was to review the scientific literature on the ecotoxicological effects of TBZ and TBZ-based commercial formulations on fish. Historical review data (publication year and geographical distribution), TBZ type, experimental design, fish species, habitat, life stage, tissue/organ, lethal concentration (LC50), concentration and exposure time, biomarkers and effects were compiled and critically analyzed. Studies were mainly conducted with freshwater species at adult and larval stages, whereas no data were find for marine fish species. Zebrafish, (Danio rerio) was the most assessed species. Both TBZ and TBZ-based commercial formulations induced oxidative stress, endocrine disruption, neurotoxicity, genotoxicity, histopathologies, behavior impairments and mortality on fish. TBZ can induce synergistic and antagonistic effects on fish when it is combined to other pesticides. Overall, the current study has shown the potential hazardous effects of TBZ and TBZ-based commercial formulations on the health of fish.

A compatibility analysis framework for freshwater quality standards of pesticides across multiple countries: Human health, regulatory compliance, and water treatment perspectives

Pesticide residues in fresh surface water pose a threat to global water sustainability. Although more than fifty countries have promulgated freshwater quality standards for human health protection, evaluating regulatory performance is complex. This study develops multi-dimensional indicators to evaluate the regulatory performance of countries from human health, regulatory compliance, and water treatment perspectives. Indicators included the Human Health Index (HHI), the Regulatory Compliance Index (RCI), and the Water Supply Indicator (WSI), calculated based on the health risk assessment, pesticide regulatory standards, and water treatment capabilities, respectively. The analysis covered surface water quality standards from 53 countries and 10 pesticides. Results found that Palau and New Zealand respectively had the top performance in human health and regulatory compliance indicators. Palau's HHI10 was (0.60, 0.17, 1.07), indicating that 60 % of selected pesticides are regulated, 17 % pose cancer risks, and the average cancer risk is 1.07 per million people. New Zealand's RCI vector of (0.70, 0.00, 0.00) showed that 70 % of pesticides are regulated in drinking water, with no exceedances. Variations in HHI10 and RCI across countries can be attributed to the differences in chemical risk prioritization, surface water protection targets, and geographic-featured dietary cultural attitudes. Regarding water treatment indexes, results showed that in most countries, water supplier efforts to reduce health-risk pesticides and comply with regulations might have limited effectiveness, with WSIHealth value of (0.26, 0.33) and WSIRC of 0.35. This study helps identify regulatory deficiencies and suggests future research could expand pesticide selection and integrate field data.

Fish skin for water quality assessment

Pollution and the resulting decline in water quality pose a serious issue for aquatic biodiversity. Therefore, biomonitoring strategies to assess water quality need to be improved. In this study, we evaluated the possible use of fish skin histology as biomarker to monitor the water quality. Five fish species (Salmo trutta, Anguilla anguilla, Leuciscus cephalus, Barbus barbus and Rutilus rubilio) were collected from 32 river sites in the Campania region (Southern Italy), located within/outside Natura 2000 network. Body Condition Factor (BCF), Epidermis Morphological Index (EMI), Mucous Cell Index (MCI), epidermis thickness, and mucous cell size were analyzed in relation to the river site Ecological Quality Class (EQC). Negative correlation between BCF and EQC was found for S. trutta and A. anguilla, while a positive correlation was observed for L. cephalus and B. barbus. Skin histological results highlighted positive correlation between EMI and EQC in S. trutta, A. anguilla, and R. rubilio, while positive correlation between MCI and EQC was observed in S. trutta, L. cephalus, B. barbus, and R. rubilio. Epidermis thickness was negatively correlated with EQC in S. trutta, L. cephalus, and B. barbus, and positively correlated in A. anguilla. Mucous cells size appeared negatively correlated with EQC in L. cephalus and R. rubilio and positively correlated in A. anguilla. The findings of this study indicate that skin histology could be a sensitive and useful biomarker to assess water quality, suggesting its integration in biomonitoring programs. Species-specific responses need to be considered to obtain a more reliable water quality assessment.

Single and joint toxicity of ethoprophos and bispyribac-sodium to Oreochromis niloticus: biochemical and genotoxic responses

Pesticides can bioaccumulate in fish tissues, and there are serious concerns around the world about their effects on consumer health. The objective of this study was to highlight the effects of two commercial pesticides, ethoprophos and bispyribac-sodium, commonly used on high-consumption crops in Egypt, either individually or in mixture, on some biomarkers of Nile tilapia, Oreochromis niloticus, an important commercial fish species. Low concentrations of ethoprophos (96 µg/L) and bispyribac-sodium (1.28 µg/L) were selected to evaluate the effect of these substances on neurotoxic marker (acetylcholine esterase, AChE), liver function parameters (alkaline phosphatase, ALP; alanine aminotransferase, ALT; and aspartate aminotransferase, AST), and renal function parameters (creatinine and urea), as well as genotoxic marker (micronuclei, MN; and other nuclear abnormalities) during variable periods (7, 14, 21, and 28 days). The results demonstrate that ethoprophos and bispyribac-sodium pose a risk to native freshwater fish by causing detrimental effects. Both compounds, separately and in combination, induced neurotoxicity, hepatorenal biomarkers inductions, and increases in MN frequency and other erythrocytic nuclear abnormalities in a time-dependent manner. Moreover, the mixture displayed both synergistic and antagonistic interactions for examined parameters. This study highlights the importance of using validated biomarkers to monitor fish health, which may be utilized as early alarms of environmental risks.

Improving compound identification results by automatically recognizing in-source fragment ions in HRMS with AntDAS: A study on accurate pesticide screening in complex food samples

Ultrahigh-performance liquid chromatography combined with high-resolution mass spectrometry has been extensively used for compound identification in an untargeted manner. However, current methods still cannot accurately screen and identify compounds in the presence of in-source fragment ions. Here, we proposed an in-source fragment ion-based strategy to precisely recognize compounds. First, raw data files were analyzed with our newly developed AntDAS-DDA to perform feature detection and annotation. Second, in-source fragment ions from a compound were recognized based on tandem mass spectrometry (MS/MS) spectra and the similarity of chromatograms. Last, the MS/MS spectra of each fragment ion were compared with those in an in-house library to benefit compound identification. The performance of the developed strategy was comprehensively investigated using the aforementioned in-house library containing 478 pesticides. Simulated and real samples suggested that compounds were accurately identified. The match factor obtained from the classic method was improved by at least 4.3 times by the developed strategy. The developed strategy may provide a new solution for compound identification in complex food samples.

Dietary grape seed extract mitigated growth retardation, hormonal delay, and gastrointestinal toxicity induced by insecticide imidacloprid in Nile tilapia

Overusing the insecticide imidacloprid (IMD) in agriculture has led to its presence in water bodies, causing serious environmental issues and fish toxicity. This study explored the potential benefits of grape seed extract (GSE) in mitigating IMD-induced growth and hormonal and gastrointestinal toxicity in Nile tilapia. A total of 240 healthy juvenile tilapias Oreochromis niloticus (O. niloticus), weighing an average of 11.44 ± 2.01 g at 2 weeks of age, were divided equally into four groups, each with three replicates. The control group received no special treatment, while the second group was given a diet containing 2% GSE®. The third group was exposed to 1.5 µg IMD per liter of water. The fourth group was subjected to the same IMD exposure and fed a diet containing 2% GSE®. These treatments were administered continuously for 75 days. Growth indices, survival rate, biochemical parameters, and digestive enzymes were measured. In addition, the growth-related hormones, intestinal malondialdehyde (MDA), and catalase (CAT) were evaluated. Histological evaluations were conducted on the stomach, duodenum, ileum, and hepatopancreas, alongside body composition analysis. Exposure to IMD delayed growth, impaired serum biochemistry and digestive enzyme activity, altered body composition, obstructed hormonal responses, decreased CAT activity, and increased intestinal MDA. All tissues exhibited signs of degradation. Combining dietary GSE® with IMD improved the former parameters affected by IMD. In conclusion, research suggests that incorporating GSE® into the diet may help reduce the adverse effects of IMD exposure on Nile tilapia, presenting a promising opportunity to address the environmental impacts of insecticide contamination in aquatic ecosystems.

Study of feed intake rate as a physiological biomarker in Nile Tilapia, Oreochromis niloticus (Linnaeus 1758) under Chlorpyrifos and Cypermethrin exposure

Chlorpyrifos and cypermethrin are the two most extensively applied insecticides in agricultural areas across the world and are found to contaminate adjacent water bodies, posing risks to non-target aquatic organisms, including fish. Aquaculture is primarily concerned with the feeding and growth of fish. This study evaluated the effects of sub-lethal concentrations of chlorpyrifos and cypermethrin on the physiological biomarker 'feed intake rate' of Oreochromis niloticus through 96 h static renewal bioassays. The fish were fed a formulated diet containing 30 % crude protein at 5 % of their body weight per day. The feed intake rate calculation was based on the outcome of 6 h feeding of fish carried out in glass aquariums. Uneaten diets (leftovers) were carefully collected and dried, and the weight of the uneaten diets was subtracted from the total amount of dry feed delivered to determine the actual feed intake rate. In the present study, the actual feed intake rates in O. niloticus exposed to chlorpyrifos and cypermethrin varied from 3.06 ± 0.02 to 3.92 ± 0.02 g/100 g BW/d and from 3.32 ± 0.02 to 4.02 ± 0.01 g/100 g BW/d, respectively. Feeding rates and growth of O. niloticus decreased in all sub-lethal concentrations of both test pesticides when compared to the control. Even at a sub-lethal concentration of 5 μg/L chlorpyrifos and 0.5 μg/L cypermethrin, O. niloticus lost its appetite. It can be concluded that chlorpyrifos and cypermethrin even in low concentrations (μg/L) in aquatic media can affect the feed intake rate and growth in fish.

Comparative toxicotranscriptomics of longterm cypermethrin exposure to aquacultured fish Labeo catla (Catla)

Cypermethrin (CYP), a persistent synthetic pyrethroid, poses a significant threat to aquatic life. The present work aims to identify the effect of CYP on the brain and liver transcriptome profile of fish Labeo catla. CYP (0.7 µg/L) was long-term exposed to L catla, and differentially expressed genes (DEGs) were investigated using RNA-sequencing (Illumina HiSeq2500). A total of 2665 and 18,020 unigenes and 333 and 454 DEGs were identified in the brain and liver transcriptome, respectively. DEGs associated with MAPK signaling and apoptosis pathways were co-expressed in both brain and liver transcriptome, according to pathway enrichment analysis. Concurrently, steroid and terpenoid backbone biosynthesis were overexpressed in liver, suggesting induction of apoptosis and steroid production, respectively. Among the identified DEGs, fosab, nr4a1, dhcr24 and tm7sf2 were significantly enriched and molecular docking studies further supported our findings. Long-term CYP exposure also altered the levels of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and malondialdehyde (MDA) content in L. catla. The present study provides significant insights into the consequences of CYP-induced toxicity in fish and identified functional genes that could be screened for estimating the toxic load of CYP in future ecotoxicological risk assessment studies.

Effects of Difenoconazole on Tubifex tubifex: Antioxidant Activity, Insights from GUTS Predictions, and Multi-Biomarker Analysis

The increasing demand for agricultural products has led to a rise in pesticide use, resulting in the pollution of aquatic habitats and raising significant health concerns for both aquatic life and humans. Difenoconazole, a triazole fungicide, is becoming increasingly popular in agriculture, yet its effects on non-target organisms, such as annelids, are not well understood. This study aimed to investigate the toxicological effects of difenoconazole and assess its potential impact on toxicity biomarkers, using Tubifex tubifex as a model organism, to better understand the ecotoxicity of difenoconazole on freshwater annelids. The 96-h LC50 value of difenoconazole was determined to be 2.68 mg/L. Sublethal concentrations (10% and 20% of the 96-h LC50 value; 0.268 and 0.536 mg/L, respectively) caused significant changes in the activities of oxidative stress enzymes. A concentration- and time-dependent decrease in the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) was observed compared to control organisms. Additionally, malondialdehyde (MDA) concentrations increased throughout the exposure period. An Integrated Biomarker Response (IBR) assessment was used to characterize and illustrate the impact of difenoconazole on T. tubifex. In conclusion, exposure to this fungicide appears to reduce the survival rate of T. tubifex at acute levels and disrupt its normal behavioral patterns. Moreover, it alters oxidative stress enzyme levels during sublethal exposure. Long-term exposure to the fungicide could potentially have population-level consequences, including a reduction in the number of individuals within a population.

Environmental dynamics of pesticides: sources, impacts on amphibians, nanoparticles, and endophytic microorganism remediation

Pesticides, which are widely used in agriculture, have elicited notable environmental concern because they persist and may be toxic. The environmental dynamics of pesticides were reviewed with a focus on their sources, impacts on amphibians, and imminent remediation options. Pesticides are directly applied in ecosystems, run off into water bodies, are deposited in the atmosphere, and often accumulate in the soil and water bodies. Pesticide exposure is particularly problematic for amphibians, which are sensitive indicators of the environment's health and suffer from physiological, behavioral, and developmental disruption that has "pushed them to the brink of extinction." Finally, this review discusses the nanoparticles that can be used to tackle pesticide pollution. However, nanoparticles with large surface areas and reactivity have the potential to degrade or adsorb pesticide residues during sustainable remediation processes. Symbiotic microbes living inside plants, known as endophytic microorganisms, can detoxify pesticides. Reducing pesticide bioavailability improves plant resilience by increasing the number of metabolizing microorganisms. Synergy between nanoparticle technology and endophytic microorganisms can mitigate pesticide contamination. Results show that Interdisciplinary research is necessary to improve the application of these strategies to minimize the ecological risk of pesticides. Eco-friendly remediation techniques that promote sustainable agricultural practices, while protecting amphibian populations and ecosystem health, have advanced our understanding of pesticide dynamics.

Hydrophobic deep eutectic solvent-ferrofluid microextraction followed by liquid chromatography-mass spectrometry for the enantioselective determination of chiral agrochemicals in natural waters

The increasing use of chiral agrochemicals sold as racemic formulations raises concern for the negative impacts that inactive enantiomers can have on aquatic life and human health. The present work just focuses on the determination of ten chiral pesticides in river water samples by applying a ferrofluid-based microextraction followed by their stereoselective liquid chromatography analysis. To develop the ferrofluid, magnetite nanoparticles were prepared and coated with oleic acid and then dispersed in a hydrophobic natural deep eutectic solvent (NaDES), composed of L-menthol and thymol (1:1). The stable colloidal dispersion was characterised by scanning electron microscopy, thermogravimetric analysis, energy-dispersive X-ray spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The analyte microextraction from 5 ml river samples was performed using 50 µl of ferrofluid, while acidified acetonitrile (150 µl) was used to break down the ferrofluid and solubilise the NaDES containing the analytes. All the extracts were analysed by high-performance liquid chromatography-tandem mass spectrometry. For each analyte, the baseline separation of isomers was achieved on a Lux i-Amylose-3 column (amylose tris(3-chloro-5-methylphenylcarbamate) working in reversed-phase mode; the combination with mass spectrometry detection allows the overall separation of 24 isomers (ten chiral analytes among which eight containing a single (one) chiral centre, one with two chiral centres and the last one existing in four stereoisomeric forms, due to the presence of two regioisomers with a chiral carbon) within 37 min. The method showed very good figures of merit in terms of recoveries (77.7-97.5%), intra-day and inter-day precision (2.7-7.7% and 6.9-14.9%, respectively), limit of detection (0.01-0.35 µg/L), limit of quantitation (0.03-1.20 µg/L), linear dynamic range, and intra-day and inter-day accuracy (1.2-14.8% and 1.8-15.0%, respectively). The presented method was able to detect 14 out of 24 isomers at the preventive limit established by the Italian legislation for single pesticide (that for a chiral pesticide is the sum of all its isomers) in surface waters, set at 0.1 µg/l. Finally, the method was evaluated using AGREEprep and ComplexGAPI metrics, compared with other ferrofluid-based methods, and applied to the analysis of water samples from two Italian rivers (the Nera River and the Tiber River), providing to be sustainable and reliable for the application to real river matrices.

Tick Control Strategies: Critical Insights into Chemical, Biological, Physical, and Integrated Approaches for Effective Hard Tick Management

Ticks and tick-borne diseases significantly impact animal health, public health, and economic productivity globally, particularly in areas where the wildlife-livestock interface complicates management. This review critically examines the current control strategies, focusing on chemical, biological, physical, and integrated pest management (IPM) approaches. Chemical acaricides, while effective, are increasingly challenged by resistance development and environmental concerns. Biological approaches, including natural predators and entomopathogenic fungi, and physical interventions, such as habitat modification, provide sustainable alternatives but require further optimization. IPM stands out as the most promising long-term solution, integrating multiple approaches to enhance efficacy while reducing environmental risks. Emerging innovations, such as nanotechnology-enhanced acaricides and next-generation vaccines, offer promising avenues for improved tick control. Addressing the complex challenges of tick management requires tailored strategies, interdisciplinary collaboration, and sustained research investment in both veterinary and public health contexts.

Environmental and occupational exposure to organochlorine pesticides associated with Parkinson's disease risk: A systematic review and meta-analysis based on epidemiological evidence

OBJECTIVES

The purpose of this study was to analyze the association between environmental and occupational organochlorine pesticides (OCPs) exposure and Parkinson's disease (PD) risk.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive search of articles before March 18, 2024, was conducted through PubMed, Cochrane, Embase, Medlin and Web of Science databases, and the relevant data were expressed as odds ratios (OR) and 95 % confidence intervals (CI). Newcastle-Ottawa Scale (NOS) was used to evaluate literature quality. STATA (Version 11.0) was used for analysis.

RESULTS

This meta-analysis included 17 case-control studies. The results showed that OCPs exposure increased PD risk, including seven blood sample assessment exposure (BOCPs) studies (OR = 1.54, 95 % CI = 1.32-1.79) and 10 indirect assessment exposure (IOCPs) studies (OR = 1.19, 95 % CI = 1.04-1.35). Location subgroup analysis showed that OCPs was positively associated with PD risk in Asia, while there was no statistical significance in North America and Europe. The IOCPs functional subclasses subgroup results suggested that organochlorine insecticides were significantly associated with PD risk (OR = 1.18, 95%CI = 1.03-1.37). Study time may be a factor of high heterogeneity in BOCPs. In addition, BOCPs (OR = 1.49, 95%CI = 1.28-1.74) and IOCPs (OR = 1.10, 95%CI = 0.95-1.26) showed different results with PD risk.

CONCLUSIONS

Study suggests that OCPs exposure may be a risk factor for PD, but there may be location and OCPs type differences.

Biodegradation of chemical contamination by lactic acid bacteria: A biological tool for food safety

Chemical pollutants such as mycotoxins and pesticides exert harmful effects on human health such as inflammation, oxidative stress, and cancer. Several strategies were applied for food decontamination, including physicochemical and biological strategies. The present review comprehensively discussed the recent efforts related to the biodegradation of eight food chemical contaminants, including mycotoxins, acrylamide, biogenic amines, N-nitrosamines, polycyclic aromatic hydrocarbons, bisphenol A, pesticides, and heavy metals by lactic acid bacteria (LAB). Biological detoxification by LAB such as Lactobacillus is a promising approach to remove the risks related to the presence of chemical and environmental pollutants in foodstuffs. It is a safe, efficient, environmentally friendly, and low-cost strategy to remove hazardous compounds. LAB can directly decrease these chemical pollutants by degradation or adsorption. Also, it can indirectly reduce the content of these pollutants by reducing their precursors. Hence, LAB can contribute to reducing chemical pollutants in contaminated foods and enhance food safety.

The role of marine bacteria in modulating the environmental impact of heavy metals, microplastics, and pesticides: a comprehensive review

Bacteria assume a pivotal role in mitigating environmental issues associated with heavy metals, microplastics, and pesticides. Within the domain of heavy metals, bacteria exhibit a wide range of processes for bioremediation, encompassing biosorption, bioaccumulation, and biotransformation. Toxigenic metal ions can be effectively sequestered, transformed, and immobilized, hence reducing their adverse environmental effects. Furthermore, bacteria are increasingly recognized as significant contributors to the process of biodegradation of microplastics, which are becoming increasingly prevalent as contaminants in marine environments. These microbial communities play a crucial role in the colonization, depolymerization, and assimilation processes of microplastic polymers, hence contributing to their eventual mineralization. In the realm of pesticides, bacteria play a significant role in the advancement of environmentally sustainable biopesticides and the biodegradation of synthetic pesticides, thereby mitigating their environmentally persistent nature and associated detrimental effects. Gaining a comprehensive understanding of the intricate dynamics between bacteria and anthropogenic contaminants is of paramount importance in the pursuit of technologically advanced and environmentally sustainable management approaches.

Assessment of organochlorine pesticide contamination in Astyanax altiparanae from the Alagados Dam, Southern Brazil

Organochlorine pesticides (OCPs) are persistent pollutants previously used in agriculture, known for their ability to bioaccumulate and pose health risks. This study analyzed samples of roe, viscera, and muscle from Astyanax altiparanae fish collected from the Alagados reservoir in Paraná, Brazil. Samples were prepared through extraction and purification, then analyzed using gas chromatography with an electron capture detector (GC/ECD), chosen for its sensitivity in detecting OCPs. The method was validated for precision, accuracy, and detection limits. Detected OCPs included Aldrin (17.1 to 50.6 ng/g in roe), α-endosulfan (3.4 to 23.5 ng/g), p, p'-DDE (4.2 to 134.7 ng/g), Dieldrin (84.7 to 183.1 ng/g), β-endosulfan (6.0 to 51.6 ng/g), and p, p'-DDT (56.6 to 286.8 ng/g). In viscera, concentrations ranged from Aldrin (19.8 to 93.3 ng/g) to p, p'-DDT (52.3 to 89.2 ng/g). Muscle samples showed similar trends. Principal component analysis indicated a link between higher OCP concentrations and increased abdominal width of the fish. While OCP levels were below FAO and WHO limits, risk quotient calculations suggest potential health risks from consuming these fish.

Feeding global aquaculture

The growth of animal aquaculture requires ever more feed. Yet, fish and crustacean farming is argued to be sustainable because wild fish use is low and has improved over time. Here, accounting for trimmings and by-products from wild fish in aquaculture feed, and using four different sources of industry-reported feed composition data, we find ratios of fish inputs to farmed outputs of 0.36 to 1.15-27 to 307% higher than a previous estimate of 0.28. Furthermore, a metric that incorporates wild fish mortality during capture and excludes unfed systems raises the wild fish mortality-to-farmed fish output ratio to 0.57 to 1.78. We also evaluate terrestrial ingredients in aquaculture feeds. Widely cited estimates of declines in wild fish use from 1997 to 2017 entailed a trade-off of more than fivefold increase in feed crops over the same period. Our assessment challenges the sustainability of fed aquaculture and its role in food security.

Bioaccumulation of Deltamethrin and Piperonyl butoxide in Labeo rohita fish

Deltamethrin (DLM), in combination with the synergist piperonyl butoxide (PBO), is extensively used in pest control programs due to its potent pesticidal properties and appreciable safety margin. However, various research studies report their adverse effects on non-target organisms. In this study, we investigated the toxicity of DLM, PBO, and a DLM-PBO (3:1) combination on Labeo rohita (L. rohita) fish fingerlings. Fish behavior and mortality rates were recorded at different time intervals up to 96 h for concentrations of 0.003, 0.007, 0.015, 0.031, and 0.062 µg/mL, respectively. Biochemical, hematological, and histopathological studies were carried out. High-performance liquid chromatography (HPLC) was used to detect and quantify residues in fish samples. The LC50 values after 48 h for DLM, PBO, and DLM-PBO exposed fish fingerlings were found to be 0.028, 0.066, and 0.007 µg/mL, respectively. At a concentration of 0.003 µg/mL of DLM, PBO, and DLM-PBO, the treated fish fingerlings exhibited similar behavior to the control group. Hematological parameters, such as red blood cell (RBC) and white blood cell (WBC) counts, were reduced in the treated groups compared to the control. Biochemical parameters showed increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), while total serum protein levels decreased in DLM, PBO, and DLM-PBO treated fingerlings. Histopathological examination of liver, gill, and heart tissues revealed lesions with hydropic degeneration in the liver and fusions of gill lamellae in the treated tissues. Fish fingerlings exposed to the DLM-PBO combination appeared highly prone to toxicity compared to those treated with DLM and PBO separately.

Spatiotemporal distribution, ecological risk assessment, and human health implications of currently used pesticide (CUP) residues in the surface water of Feni River, Bangladesh

Spatiotemporal monitoring of pesticide residues in river water is urgently needed due to its negative environmental and human health consequences. The present study is to investigate the occurrence of multiclass pesticide residue in the surface water of the Feni River, Bangladesh, using an optimized salting-out assisted liquid-liquid microextraction (SALLME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimized SALLME method was developed and validated following the SANTE/11312/2021 guidelines. A total of 42 water samples were collected and analyzed to understand the spatiotemporal distribution of azoxystrobin (AZ), buprofezin (BUP), carbofuran (CAR), pymetrozine (PYM), dimethoate (DMT), chlorantraniliprole (CLP), and difenoconazole (DFN). At four spike levels (n = 5) of 20, 40, 200, and 400 μg/L, the recovery percentages were satisfactory, ranging between 71.1 % and 107.0 % (RSD ≤13.8 %). The residues ranged from below the detection level (BDL) to 14.5 μg/L. The most frequently detected pesticide was DMT (100 %), followed by CLP (52.3809-57.1429), CAR (4.7619-14.2867), and PYM (4.7619-9.5238). However, AZ and BUP were below the detection limit in the analyzed samples of both seasons. Most pesticides and the highest concentrations were detected in March 2023, while the lowest concentrations were present in August 2023.Furthermore, ecological risk assessment based on the general-case scenario (RQm) and worst-case scenario (RQex) indicated a high (RQ > 1) risk to aquatic organisms, from the presence of PYM and CLP residue in river water. Human health risk via dietary exposure was estimated using the hazard quotient (HQ). Based on the detected residues, the HQ (<1) value indicated no significant health risk. This report provides the first record of pesticide residue occurrences scenario and their impact on the river environment of Bangladesh.

Ecological impacts and management strategies of pesticide pollution on aquatic life and human beings

Pesticide contamination has become a global concern. Pesticides can sorb onto suspended particles and deposit into the sedimentary layers of aquatic environments, resulting in ecosystem degradation, pollution, and diseases. Pesticides impact the behavior of aquatic environments by contaminating organic matter in water, which serves as the primary food source for aquatic food webs. Pesticide residues can increase ammonium, nitrite, nitrate, and sulfate in aquatic systems; thus, threatening ecological environment and human health. Several physical, chemical, and biological methodologies have been implemented to effectively remove pesticide traces from aquatic environments. The present review highlights the potential consequences of pesticide exposure on fish and humans, focusing on the (epi)genetic alterations affecting growth, behavior, and immune system. Mitigation strategies (e.g., bioremediation) to prevent/minimize the detrimental impacts of pesticides are also discussed. This review aims to shed light on the awareness in reducing the risk of water pollution for safe and sustainable pesticide management.

Comparative Acute Toxicity Studies of Chlorpyrifos Technical Grade with its Emulsifiable Concentrate (20% EC) on Labeo rohita, a Freshwater Major Carp, and Mystus vittatus, a Freshwater Catfish

Chlorpyrifos is widely used across the world as an organophosphate insecticide and frequently contaminates freshwater bodies through runoff from agricultural fields. In the laboratory, static bioassays were undertaken to examine differences in acute toxicity caused by exposure to the technical grade (94% a.i.) and an emulsifiable concentrate (20% EC) of chlorpyrifos to two species of freshwater fish, Labeo rohita and Mystus vittatus. The recovery of actual chlorpyrifos concentrations varied from 83% (technical grade, T) to 89% (emulsifiable concentrate, F) after two hours in water. The susceptibilities of the two fish species to the two types of chlorpyrifos varied. The 96-h LC50 values for T and F chlorpyrifos in L. rohita were 68 and 36 µg/L, respectively, and 120 and 62 µg/L in M. vittatus, respectively. As the exposure period was extended, the LC50 values gradually decreased. LC50 values between the technical grade and formulation were compared following the criteria of Mayer et al. (1986), Schmuck et al. (1994), APHA (1995), and Demetrio et al. (2014). It was concluded from the study that the emulsifiable concentrate (20% EC) of chlorpyrifos was more toxic than technical-grade chlorpyrifos.

Ensemble multiclassification model for predicting developmental toxicity in zebrafish

In recent years, with the rapid development of society, organic compounds have been released into aquatic environments in various forms, posing a significant threat to the survival of aquatic organisms. The assessment of developmental toxicity is an important part of environmental safety risk systems, helping to identify the potential impacts of organic compounds on the embryonic development of aquatic organisms and enabling early detection and warning of potential ecological risks. Additionally, binary classification models cannot accurately classify organic compounds. Therefore, it is crucial to construct a multiclassification model for predicting the developmental toxicity of organic compounds. In this study, binary and multiclassification models were developed based on the ToxCast™ Phase I chemical library and literature data. The random forest, support vector machine, extreme gradient boosting, adaptive gradient boosting, and C5.0 decision tree algorithms, as well as 8 types of molecular fingerprint were used to establish a multiclassification base model for predicting developmental toxicity through 5-fold cross-validation and external validation. Ultimately, a multiclassification ensemble model was derived through a voting method. The performance of the binary ensemble model, as measured by the balanced accuracy, was 0.918, while that of the multiclassification model was 0.819. The developmental toxicity voting ensemble model (DT-VEM) achieved accuracies of 0.804, 0.834, and 0.855. Furthermore, by utilizing the XGBoost machine learning algorithm to construct separate models for molecular descriptors and substructure molecular fingerprints, we identified several substructures and physical properties related to developmental toxicity. Our research contributes to a more detailed classification of developmental toxicity, providing a new and valuable tool for predicting the developmental toxicity effects of unknown compounds. This supplement addresses the limitations of previous tools, as it offers an enhanced ability to predict potential developmental toxicity in novel compounds.

Toxicological assessment of bromoxynil and 2-methyl-4-chlorophenoxyacetic acid herbicide in combination on Cirrhinus mrigala using multiple biomarker approach

The widespread application of herbicides raises concerns about their impact on non-target aquatic organisms. This study aimed to evaluate the toxicity of a commercially available herbicide formulation containing Bromoxynil+MCPA (2-Methyl-4-chlorophenoxyacetic acid) on Cirrhinus mrigala (economically significant fish). A total of 210 juvenile fish were subjected to a triplicate experimental setup, with 70 fish allocated to each replicate, exposed to seven different concentrations of herbicide: 0 mg/L, 0.133 mg/L, 0.266 mg/L, 0.4 mg/L, 0.5 mg/L, 0.66 mg/L, and 0.8 mg/L, respectively, for a duration of 96 h. The median lethal concentration (LC50) was determined to be 0.4 mg/L. Significant hematological alterations were observed, including decreases in RBC counts, hemoglobin, hematocrit, and lymphocyte counts, along with an increase in erythrocyte indices. Biochemical analysis revealed elevated levels of neutrophils, WBCs, bilirubin, urea, creatinine, ALT, AST, ALP, and glucose in treated groups. Morphological abnormalities in erythrocytes and histopathological changes in gills, liver, and kidneys were noted. Pathological alterations in gills, liver and kidneys including epithelial cell uplifting, lamellar fusion, hepatolysis, and renal tubule degeneration were observed. Oxidative stress biomarkers such as TBARS (Thiobarbituric Acid Reactive Substance), ROS (Reactive Oxygen Species), and POD (Peroxides) activity increased, while antioxidant enzymatic activities decreased as toxicant doses increased from low to high concentrations. The study reveals that Bromoxynil+MCPA significantly disrupts physiological and hematobiochemical parameters in Cirrhinus mrigala, which highlights the substantial aquatic risks. In conclusion, the herbicide formulation induced significant alterations in various fish biomarkers, emphasizing their pivotal role in assessing the environmental impact of toxicity. This multi-biomarker approach offers valuable insights regarding the toxicological effects, thereby contributing substantially to the comprehensive evaluation of environmental hazards.