Journal of Xenobiotics

Mercury (Hg) pollution is a widespread ecological threat with sublethal effects on wildlife. Birds, due to their ecological diversity and sensitivity, serve as effective models for evaluating the behavioural impacts of Hg exposure. This review applies Tinbergen’s four questions: causation, ontogeny, function, and evolution, as an integrative framework. Mechanistically, Hg disrupts neuroendocrine pathways, gene expression, immune function, and hormone regulation, leading to behavioural changes such as reduced foraging, altered parental care, and impaired predator avoidance. Early-life exposure affects neural development, learning, and social behaviour into adulthood. Functionally, these changes reduce fitness by compromising reproduction and survival. Phylogenetic comparisons show interspecific variability, with piscivorous and insectivorous birds exhibiting high Hg burdens and sensitivity, linked to ecological roles and exposure. Behavioural responses often precede physiological or demographic effects, highlighting their value as early indicators. Both field and laboratory studies show that even low Hg concentrations can alter behaviour, though outcomes vary by species, life stage, and exposure route. Integrating behavioural endpoints into ecotoxicological risk assessments is essential to improve conservation strategies and understanding of sublethal pollutant effects on wildlife. Full article

Background: Butylated hydroxyanisole (BHA) has been extensively used in several commercial industries as a preservative. It causes severe cellular and neurological damage affecting the developing fetus and might induce attention deficit hyperactivity disorder (ADHD). Methods: Zebrafish embryos were subjected to five distinct doses of BHA—0.5, 1, 2, 4, and 8 ppb up to 96 h post fertilization (hpf). Hatching rate, heart rate, and body malformations were assessed at 48 hpf, 72 hpf, and 48–96 hpf, respectively. After exposure, apoptotic activity, neurobehavioral evaluation, neurotransmitter assay, and antioxidant activity were assessed at 96 hpf. At 120 hpf, the expression of genes DRD4, COMT, 5-HTR1aa, and BDNF was evaluated by real-time PCR. Results: BHA exposure showed a delay in the hatching rate and a decrease in the heart rate of the embryo when compared with the control. Larvae exhibited developmental deformities such as bent spine, yolk sac, and pericardial edema. A higher density of apoptotic cells was observed in BHA-exposed larvae at 96 hpf. There was a decline in catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and superoxide dismutase (SOD) activity, indicating oxidative stress. There was a significant decrease in Acetylcholinesterase (AChE) activity and serotonin levels with an increase in concentration of BHA, leading to a dose-responsive increase in anxiety and impairment in memory. A significant decrease in gene expression was also observed for DRD4, COMT, 5-HTR1aa, and BDNF. Conclusions: Even at lower concentrations of BHA, zebrafish embryos suffered from developmental toxicity, anxiety, and impaired memory due to a decrease in AChE activity and serotonin levels and altered the expression of the mentioned genes. Full article

Arsenic exposure in children and adults has been associated with respiratory symptoms, respiratory infections, and decreased lung function. The goal of this study was to evaluate the relationship between environmental arsenic exposure and serum pneumoproteins and lung function. A cross-sectional study was conducted including 175 children exposed to arsenic by drinking water (range: 7.4 to 91 µg/L) and soil (range: 4.76 to 35.93 mg/kg), from some Yaqui villages. Arsenic was analyzed in dust and urine using field-portable X-ray fluorescence spectrometry and ICP/OES, respectively. Serum was analyzed for Clara Cell protein (CC16) and Matrix Metalloproteinase-9 (MMP-9) using immunoassays, and lung function was evaluated by spirometry. The results showed that increased arsenic in drinking water was associated with reduced forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) ratio (β = −0.027, p = 0.0000) whereas, contrary to expectations, arsenic in dust was associated with increased FEV₁/FVC (β = 0.004, p = 0.0076). Increased urinary arsenic was associated with reduced % predicted FEV₁ (β = −0.723, p = 0.0152) and reduced FEV₁/FVC ratio (β = −0.022, p = 0.0222). Increased serum MMP-9 was associated with reduced FEV₁/FVC ratio (β = −0.017, p = 0.0167). Children with % predicted FEV₁ values less than 80 had the lowest levels of CC16 (Median 29.0 ng/mL, IQR 21.3, 37.4, p = 0.0148). As a conclusion, our study evidenced an impairment in lung function in children exposed to low arsenic levels. Full article

Aspartame, a widely used artificial sweetener, has been at the center of ongoing debates concerning its safety, particularly its potential role in cancer development. This review provides an overview and analysis of the current research exploring the carcinogenic effects of aspartame. It examines findings from in vitro studies, in vivo experiments, and epidemiological investigations to offer a comprehensive perspective on the controversy. The results from these studies remain inconsistent—some suggest a possible association between high aspartame intake and increased cancer risk, while others fail to establish a conclusive link. Additionally, this review explores potential mechanisms by which aspartame could exert carcinogenic effects, focusing on its metabolic byproducts and their influence on cellular and molecular processes. Despite these investigations, the question of aspartame’s safety remains unresolved. Continued research is essential to clarify its role in cancer risk and to inform evidence-based dietary guidelines. Full article

Contaminants such as nano-polystyrenes (NPs) and heavy metal cocktail (HMC) have been found to disrupt physiological functions in aquatic organisms. Although HMC and NPs alone induce oxidative stress, their combined effects are not well understood. This study aimed to assess the combined effects of HMC and NPs on the freshwater shrimp (Macrobrachium rosenbergii). Shrimp were divided into seven groups, including the control group, and the experimental groups co-exposed to 0, 50, 100, 150, 200, and 250 µg/L NPs combined with 0.5 mg/L HMC. After 14 days, shrimp were sampled, and their hepatopancreas and muscle tissues were analyzed for oxidative biomarkers, biochemical parameters, and metabolic profiles. Moreover, the bioaccumulation rate of heavy metals was measured. Results showed that co-exposure to NPs and HMC increased superoxide dismutase, glutathione peroxidase, glutathione reductase activities, and malondialdehyde levels, while reducing glutathione and total antioxidant capacity. The integrated biomarker response indicated that co-exposure to HMC and NPs induces oxidative stress. A significant decrease was observed in aspartate aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase activities, glycogen, triglyceride, and total protein levels. However, lactate dehydrogenase activity was significantly increased. Co-exposure to HMC and NPs increased heavy metal bioaccumulation, induced oxidative stress, biochemical changes, and enhanced HMC toxicity in shrimp. Full article

This study investigated the ecotoxicological impacts of environmentally relevant concentrations (0.05, 0.50, and 5.00 mg/L) of nickel nanoparticles (Ni-NPs) by assessing oxidative stress biomarkers. The worm Hediste diversicolor, the bivalve Mytilus spp., and the fish Sparus aurata were chronically exposed to Ni-NPs for 28 days, and glutathione S-transferases (GST), catalase (CAT), and thiobarbituric acid reactive substances (TBARS) levels were measured to evaluate biochemical responses. GST activity increased in H. diversicolor and the liver of S. aurata, suggesting a key role for this enzyme in Ni-NPs detoxification. CAT activity was inhibited in the digestive gland of Mytilus spp. at the highest Ni-NPs concentration, indicating possible disruption of antioxidant defense. TBARS levels rose significantly in the gills of Mytilus spp. exposed to high Ni-NP concentrations, suggesting oxidative damage beyond detoxification capacity. In contrast, TBARS decreased in the digestive gland of Mytilus and in H. diversicolor, possibly due to compensatory upstream antioxidant responses. These findings indicate that each species exhibits distinct adaptive responses to Ni-NP exposure. Overall, this study highlights the need to consider species- and tissue-specific responses when performing ecotoxicological risk assessments of nanomaterials. Full article

The polyunsaturated fatty acids of the omega-3 class have been widely investigated due to their antitumor properties, including in prostate cancer (PCa). Among them is docosahexaenoic acid (DHA, C22:6 ω-3), whose biological activity is higher than other omega-3s, exhibiting a stronger impact on PCa. The specific mechanisms triggered by DHA are blurred by studies that used a blend of omega-3s, delaying the understanding of its biological role, and hence alternative therapeutic approaches. DHA is differentially processed between normal and malignant epithelial PCa cells, which suggests its function as a tumor suppressor. At cell-specific level, it downregulates key pathways in PCa, such as androgen signaling and lipid metabolism, but also changes membrane composition by disrupting phospholipid balance and increasing unsaturation status, arrests the cell cycle, and induces apoptosis and reactive oxygen species (ROS) overproduction. At the tissue level, DHA seems to influence stromal components, such as the inhibition of cancer-associated fibroblast differentiation and resolution of inflammation, which generates a microenvironment favorable to PCa initiation and progression. Considering that such effects are misunderstood and assigned to omega-3s in general, this review aims to discuss the specific effects of DHA on PCa based on in vitro and in vivo evidence. Full article

The escalating global contamination of aquatic ecosystems by pharmaceuticals and endocrine-disrupting chemicals (EDCs) stemming from diverse anthropogenic sources represents a critical and pervasive threat to planetary Earth. These contaminants exhibit bioaccumulative properties in long-lived organisms and undergo trophic biomagnification, leading to elevated concentrations in apex predators. This review synthesizes current knowledge regarding the far-reaching impacts of pharmaceutical and EDC pollution on the reproductive biology of aquatic fauna, focusing on the heightened vulnerability of the endangered African penguin. A rigorous literature review across key scientific databases—PubMed, Scopus, Web of Science, and Google Scholar—using targeted search terms (e.g., penguins, contaminants of emerging concern, penguin species, seabird species, Antarctica, pharmaceuticals, personal care products, EDCs) underpins this analysis. This review explores the anthropogenic sources of pharmaceuticals and EDCs in aquatic ecosystems. It discusses the mechanisms by which these chemicals disrupt the reproductive physiology of aquatic fauna. Recent studies on the ecological and population-level consequences of these contaminants are also reviewed. Furthermore, the review elaborates on the urgent need for comprehensive mitigating strategies to address their effects on vulnerable penguin populations. These approaches hold the potential to unlock innovative pathways for conservation initiatives and the formulation of robust environmental management policies aimed at safeguarding aquatic ecosystems and the diverse life they support. Full article

Antioxidants derived from plant extracts have attracted considerable attention due to their potential in mitigating oxidative damage through free radical scavenging mechanisms. Although 700 species have been used for centuries in Georgian traditional medicine, the chemical composition and antioxidant and antibacterial properties of Caucasian endemic medicinal plants remain largely unknown. In this study, the antioxidant and antibacterial activities of leaf and root extracts of Caucasian endemic medicinal plants Sempervivum transcaucasicum Muirhead and Paeonia daurica subsp. mlokosewitschii (Lomakin) D. Y. Hong were investigated. The highest antioxidant activity and phenolic and flavonoid content were revealed in Paeonia daurica leaf extract. The analysis of the content of water-soluble antioxidants revealed the highest content of reduced glutathione and ascorbate in Paeonia daurica leaves. Moreover, the antibacterial activity of leaf and root extracts against Escherichia coli ATCC 25922 strain was investigated, and minimal inhibitory concentration (MIC) values were determined. While the antibacterial activity against E. coli ATCC 25922 was not revealed for the Sempervivum transcaucasicum leaf extract, antibacterial properties were detected for the root extract (MIC 5 mg/mL). Collectively, the highest antibacterial activity was revealed for Paeonia daurica leaf and root extracts (MIC 2 mg/mL and 3 mg/mL, respectively). From a molecular perspective, molecular docking simulations were performed using HDOCK software, with reduced glutathione and ascorbic acid as ligands, in order to analyse their potential binding affinity to the OmpX protein. Inhibiting this protein would likely disrupt bacterial function and produce an antibacterial effect. Our results provide a possible mechanism for the antibacterial activity of Paeonia daurica subsp. mlokosewitschii. Overall, the results of the study demonstrate the potential of Caucasian endemic medicinal plants as natural antioxidants and antimicrobial agents. Full article

In the present investigation, an eco-friendly biocatalyst was developed using Pleurotus eryngii laccase (PeLac) through a copper (Cu)-based protein–inorganic hybrid system for the degradation of bisphenol A, a representative xenobiotic. After partial purification, the specific activity of crude PeLac was 92.6 U/mg of total protein. Immobilization of PeLac as Cu₃(PO₄)₂–Lac (Cu–PeLac) nanoflowers (NFs) at 4 °C resulted in a relative activity 333% higher than that of the free enzyme. The Cu–PeLac NFs exhibited greater pH and temperature stability and enhanced catalytic activity compared to free laccase. This enhanced activity was validated through improved electrochemical properties. After immobilization, Cu–PeLac NFs retained up to 8.7-fold higher residual activity after storage at 4 °C for 30 days. Free and immobilized laccase degraded bisphenol A by 41.6% and 99.8%, respectively, after 2 h of incubation at 30 °C. After ten cycles, Cu–PeLac NFs retained 91.2% degradation efficiency. In the presence of potent laccase inhibitors, Cu–PeLac NFs exhibited a 47.3-fold improvement in bisphenol A degradation compared to free PeLac. Additionally, the synthesized Cu–PeLac NFs demonstrated lower acute toxicity against Vibrio fischeri than Cu nanoparticles. This study presents the first report of PeLac immobilization through an eco-friendly protein–inorganic hybrid system, with promising potential for degrading bisphenol A in the presence of inhibitors to support sustainable development. Full article

Background: Remdesivir (RDV) is a broad-spectrum antiviral prodrug, which is rapidly metabolized in vivo within cells to the pharmacologically active triphosphate metabolite, GS-443902. On the other hand, the dephosphorylated metabolite GS-441524 is the main form detected in plasma. RDV acts against RNA viruses, and it was the first antiviral drug to receive EMA and FDA approval for treating COVID-19. Nevertheless, its intracellular pharmacokinetics in real life are poorly explored, particularly due to technical challenges. Methods: The aim of this study was to validate an HPLC-MS/MS method for the direct quantification of GS-443902 in peripheral blood mononuclear cells (PBMCs) with a chromatographic separation of 15 min. Results: The method was validated following EMA and FDA guidelines in terms of sensitivity, specificity, accuracy, precision, matrix effect, recovery, carryover, and stability, and then applied to PBMC isolates from a small cohort of patients with severe COVID-19 who received RDV. Conclusions: This work represents the first method for the direct quantification of GS-443902 in PBMCs, with possible future application to intracellular pharmacokinetic studies in different scenarios, such as new oral prodrugs or drug–drug interaction studies. Full article

The knowledge about the potential toxic effects of microplastics (MPs) combined with herbicides at lower trophic levels is still largely unknown. The present study aimed to evaluate the potential toxic effects of polyethylene terephthalate (PET) and polyamide (PA), isolated or combined with the pesticide glyphosate (GLY), on the microalgae Arthrospira platensis. For this, microalgae were exposed to control, GLY (3 μg/L), PET (0.5 and 1 mg/L), PA (0.5 and 1 mg/L), and the respective mixtures of each MP with GLY, for 12 days. The photosynthetic pigment content, phytochemicals, antioxidants, and enzymatic activity were determined. Cell growth was significantly enhanced on day 4 in the GLY+PA1 group (~80%), compared to the control. At day 12, biomass was significantly higher in the GLY (~25%) and GLY+PET0.5 (~26%) groups relative to the control. Significant effects on the enzymatic and detoxification mechanisms were observed, including increased SOD (PET0.5, p = 0.011) and CarE (GLY, PA and GLY+PA, p < 0.01), and decreased GST in combined exposures, which support stress-induced enzymatic activation and adaptive biochemical responses. Significant effects on phytochemicals and antioxidant activity were also observed, with PET0.5 significantly reducing total carotenoids (~65%), and flavonoids (p < 0.001) and ortho-diphenols (p < 0.05) being decreased in all exposure groups, in comparison to the control group. The decrease in flavonoids and ortho-diphenols, important antioxidant molecules, suggests the depletion of these key compounds under stress. DPPH scavenging activity, a measure of antioxidant potential, was inhibited in the GLY+PA groups, indicating compromised antioxidant defense. Results confirmed that combined stressors elicit distinct and sometimes deleterious responses not predicted by single exposures. Our findings highlight that the combined exposure to glyphosate and MPs significantly disrupts antioxidant defenses and enzymatic activity in A. platensis, indicating potential risks to primary producers in aquatic ecosystems and underscoring the ecological implications of co-contaminant stressors. In fact, the results indicate that MPs can modify herbicide toxicity, posing enhanced risks to microalgal physiology and potentially affecting primary productivity and nutrient cycling in aquatic ecosystems. In turn, negative effects of MPs on microalgae can have serious consequences for food webs, food security, and ecological health. Full article

Climate change, mining activities, pollution and other human impacts on the natural environment cause significant changes in the concentrations and mixtures of metallic elements found in different ecosystems. Metals such as cadmium, copper, lead and mercury affect multiple aspects of host–pathogen interactions, influencing the risk of infectious diseases caused by various classes of pathogens. Notably, exposure to metals in doses and combinations toxic to the immune system can favor the dissemination of pathogens in natural environments, threatening the reproduction, well-being and survival of varied animal species. However, these problems remain neglected, since the influences of metals on infectious diseases are studied with a primary focus on human medicine. Therefore, this article aims to review the influence of metals/metalloids (e.g., arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, zinc) on infectious and parasitic diseases in animals living in natural environments. The potential impact of metals on the risk of zoonotic spillover events is also discussed. Metal pollution tends to increase as the demand for elements used in the manufacture of industrial products, batteries, and electronic devices increases globally. This problem can aggravate the biodiversity crisis and facilitate the emergence of infectious diseases. Considering the interconnections between pollution and immunity, measures to limit metal pollution are necessary to protect human health and biodiversity from the risks posed by pathogens. This review helps fill the gap in the literature regarding the connections between metal pollution and various aspects of infectious diseases. Full article

The evolution of global agriculture encourages the extensive use of pesticides although significant concerns regarding their impact on human health and the environment must be considered. The present paper highlights the presence and concentrations of various pesticide residues in fruits and vegetables available on Romanian markets. A total of 74 pesticide compounds authorized for agricultural use were identified and quantified in 620 randomly selected samples spanning a wide range of horticultural products by employing the QuEChERS extraction method and liquid chromatography–mass spectrometry (LC-MS/MS). The most often detected pesticides comprised boscalid and azoxystrobin, present in 42% and 37% of apple and strawberry samples, respectively, with mean concentrations of 0.12 mg/kg and 0.09 mg/kg. In cucumbers and tomatoes, difenoconazole and acetamiprid were predominant, detected in 35% and 40% of samples, with average residue amounts of 0.08 mg/kg and 0.07 mg/kg, respectively. Statistical analysis, achieved with Python 3.13.2, the pandas library (alongside descriptive statistics), and ANOVA, revealed significant variations in residue levels based on the product type and geographic origin. Boscalid and azoxystrobin were commonly encountered in apples and strawberries while difenoconazole and acetamiprid predominated in cucumbers and tomatoes. Even though the majority of pesticide residues conformed to EU maximum residue limits (MRLs), about 6% of samples, generally from imported products, displayed some residue concentrations approaching critical thresholds, with the highest exceedance observed for chlorpyrifos and lambda-cyhalothrin at concentrations of up to 0.25 mg/kg. This research provides a comprehensive overview of pesticide residues prevalence in Romania’s fresh product supply while, at the same time, supporting consumer awareness initiatives and evidencing the critical demand for continuous monitoring and strengthened regulatory frameworks for food safety. Full article

This study investigates the effect of high urban land temperatures on pesticide residue (PR) accumulation in cabbage and lettuce and on public health in the Greater Accra Metropolitan Area (GAMA) in Ghana. A comparative toxicological analysis regarding the food system was conducted with 66 farmers across three land surface temperatures: low (Atomic, n = 22), moderate (Ashaiman, n = 22), and high (Korle-Bu, n = 22). Pesticide residue concentrations were assessed using an ANOVA to examine spatial variations across sites. The results indicate a strong correlation between high land surface temperatures and pesticide residue accumulation, with lettuce recording significantly (p < 0.05) higher PR levels than cabbage. Several pesticides, including carbendazim (CBZ), Imidacloprid (IMI), Thiamethoxam (TMX), and Chlorpyrifos (CHL), exceeded the maximum residue limits (MRLs) set by the World Health Organization (WHO) and the European Union (EU) at moderate and high-temperature sites. carbendazim was the dominant pesticide detected, with a concentration of 19.0 mg/kg in lettuce, which far exceeded its maximum residue limit (MRL) of 0.10 mg/kg across all study sites. Statistical analyses (PERMANOVA) confirmed that land surface temperatures and pesticide types significantly influenced the PR concentrations. Public health risk assessments indicate that children are more vulnerable to pesticide exposure than adults. The toxicity hazard quotient (THQ) for organophosphate pesticides, particularly CHL and Dimethoate (DMT), exceeded safe thresholds at moderate and high-temperature sites. Full article

Background: Amphetamine-type stimulants (ATS) in water pose significant public health and ecological risks, necessitating reliable and efficient detection methods. Current approaches often involve time-consuming pH adjustments and post-processing steps, limiting their practicality for high-throughput analysis. This study aimed to develop a streamlined method integrating pH regulation and adsorption into a single material to simplify sample preparation and enhance analytical efficiency. Methods: A novel Fe₃O₄/MWCNTs-OH/CaO composite adsorbent was synthesized via a one-pot grinding method, embedding pH adjustment and adsorption functionalities within a single material. This innovation enabled magnetic solid-phase extraction (MSPE) without pre-adjusting sample pH or post-desorption steps. The method was coupled with liquid chromatography–tandem mass spectrometry (LC-MS/MS) for ATS detection. Optimization included evaluating adsorption/desorption conditions and validating performance in real water matrices. Results: The method demonstrated exceptional linearity (R² > 0.98), low detection limits (0.020–0.060 ng/mL), and high accuracy with relative recoveries of 92.8–104.8%. Precision was robust, with intra-/inter-day relative standard deviations (RSDs) below 11.6%. Single-blind experiments confirmed practical applicability, yielding consistent recoveries (relative errors: 1–8%) for ATS-spiked samples at 0.8 and 8 ng/mL. Compared to existing techniques, the approach reduced processing time to ~5 min by eliminating external pH adjustments and post-concentration steps. Conclusions: This work presents a rapid, reliable, and user-friendly method for ATS detection in complex environmental matrices. The integration of pH regulation and adsorption into a single adsorbent significantly simplifies workflows while maintaining high sensitivity and precision. The technique holds promise for large-scale environmental monitoring and forensic toxicology, offering a practical solution for high-throughput analysis of emerging contaminants. Full article

Background: Pharmacogenomics (PGx), a pivotal branch of personalized medicine, studies how genetic variations influence drug responses. Despite its transformative potential, the adoption of PGx in Indian clinical practice faces challenges, such as the lack of population-specific data, evidence-based guidelines, and complexities in interpreting genomic reports. Comprehensive datasets tailored to Indian patients are essential to facilitate the integration of PGx into clinical settings. Methodology: The study collates pharmacogenomic data from multiple sources, including essential drugs listed by the World Health Organization (WHO), drugs used in neonatal intensive care units (NICUs), minimum sets of alleles recommended by the Association for Molecular Pathology (AMP), and catalogs the allele frequencies from the IndiGenomes database to address gaps in actionable PGx for the Indian population. Curated datasets were used to identify pharmacogenomic variants relevant to clinical practice. Results: Overall, 24 prime genes are essential for the outcomes of 57 drugs. In adults, 18 genes influence the metabolism of 44 drugs whereas, in pediatric populations, genotypes of 18 genes significantly impact the metabolism of 18 drugs. Two over-the-counter drugs with actionable PGx variants were identified: ibuprofen and omeprazole. These findings emphasize the clinical relevance of PGx for commonly used drugs, underscoring the need for population-specific data. Conclusions: As the data of several Indian human genome projects become available, an overarching need exists to establish and regulate the dynamic actionable PGx in Indian clinical practice. This will facilitate the integration of pharmacogenomic data into healthcare, enabling effective and personalized drug therapies. Full article

High levels of pesticide use are associated with intensive crop production. Pesticides are increasingly prevalent in surface and groundwater, which is a major environmental concern. Various methods have been proposed to improve the retention and/or degradation of pesticides in soils. These methods are mainly based on soil adaptation with organic wastes to mitigate soil and water pollution. In addition, there has recently been increased interest in assessing the influence of organic waste additions on pesticide movement in soils with low contents of organic matter. Agriculture and related industries generate large amounts of waste each year. Because of their components, they have the great ability to produce high-value products for environmental restoration. This study reports on the influence of four different agro-industrial wastes (orange peel, beer bagasse, grape pomace, and gazpacho waste) used as organic amendments on the leaching of metobromuron and chlorbromuron (phenylurea herbicides) on a silty clay loam soil (gypsic–calcaric regosol) with low organic matter contents from a semiarid area (southeastern Spain). The adsorption, leaching, and dissipation processes of these herbicides were evaluated on a laboratory scale in amended and unamended soils. In addition, the main leaching indices (GUS, LIX, LEACH, M LEACH, LIN, GLI, HI, and ELI) commonly used to assess groundwater protection against pesticide pollution were evaluated. The sorption coefficients (K_OC) increased in the amended soils. Metobromuron was found in leachates in all cases, although a marked reduction was observed in amended soils, while chlorbromuron was mainly retained in soils, especially in the top layer. The disappearance time (DT₅₀) for metobromuron and chlorbromuron in soil ranged from 11 to 56 d and 18 to 95 d, respectively. All indices except GLI categorize metobromuron as mobile or very mobile in unamended soil. For chlorbromuron, GUS, LIX, LEACH, MLEACH, and Hornsby classify this compound as a medium-to-high leache, while GLI and ELI classify it as having low mobility. In amended soils, most indices classify metobromuron as transitioning to mobile, while most indices catalog chlorbromuron as immobile/transition. Full article

The use of cellular energy allocation (CEA) as a physiological energetic biomarker is useful for detecting the sublethal effects of environmental contaminants. The CEA assesses the health and energy status of organisms, serving as a reliable indicator for monitoring the health of aquatic ecosystems. This study aimed to evaluate the impact of emerging contaminants already listed as a priority for monitoring in freshwater ecosystems, namely sulfamethoxazole (0.156–2.50 mg/L), trimethoprim (25.0–400 mg/L), 4-chloroaniline (5.21–20.0 mg/L), and 3,4-dichloroaniline (0.38–4.00 mg/L), on the CEA of D. rerio embryos. A standard fish embryo toxicity test was conducted, and an adaptation of the allometric scaling approach was developed through the relationship between the size and the fresh weight of the embryos. All the compounds affected the fractions of the energy reserves (total carbohydrate, lipid, and protein contents) differently, with carbohydrates being the predominant energy fraction and the most responsive indicator. Although the energy consumed showed no significant changes, the CEA was notably altered after exposure to all the contaminants, indicating a direct connection to shifts in the available energy. The CEA alterations may indicate a reallocation of energy toward detoxification, combating the stress of contaminant exposure. Energy allocation biomarkers provide a comprehensive assessment of an organism’s physiological state, which is essential for evaluating emerging contaminants’ impacts, safeguarding aquatic ecosystems, and shaping effective environmental policies. Full article