Chemical Risk Assessment Research Articles

A framework for categorizing sources of uncertainty in in silico toxicology methods: considerations for chemical toxicity predictions.

Improving regulatory confidence and acceptance of in silico toxicology methods for chemical risk assessment requires assessment of associated uncertainties. Therefore, there is a need to identify and systematically categorize sources of uncertainty relevant to the methods and their predictions. In the present study, we analyzed studies that have characterized sources of uncertainty across commonly applied in silico toxicology methods. Our study reveals variations in the kind and number of uncertainty sources these studies cover. Additionally, the studies use different terminologies to describe similar sources of uncertainty; consequently, a majority of the sources considerably overlap. Building on an existing framework, we developed a new uncertainty categorization framework that systematically consolidates and categorizes the different uncertainty sources described in the analyzed studies. We then illustrate the importance of the developed framework through a case study involving QSAR prediction of the toxicity of five compounds, as well as compare it with the QSAR Assessment Framework (QAF). The framework can provide a structured (and potentially more transparent) understanding of where the uncertainties reside within in silico toxicology models and model predictions, thus promoting critical reflection on appropriate strategies to address the uncertainties.

Is environmental risk assessment possible with the alternatives to acute fish toxicity test? Case study with pharmaceuticals

BackgroundAcute fish toxicity test (AFT) is one of the cornerstones of environmental risk assessment (ERA) of chemicals for the aquatic environment. Despite many efforts to find an alternative able to fully replace the test, there is still lasting pressure from stakeholders for AFT results. ResultsHere, we present the results of a case study with eight pharmaceuticals from various pharmaceutical groups with different levels of expected toxicity to fish. Selected compounds were tested in two validated alternative tests—fish embryo toxicity test with zebrafish (Danio rerio) (zFET) and in vitro RTgill-W1 assay according to their corresponding OECD guidelines TG 236 and TG 249, respectively. Data for AFT were collected from PubMed and ECOTOX knowledgebase databases, and acute toxicity to fish was further predicted in silico by the ECOSAR program. Predicted environmental risks (risk quotients, RQ, calculated using the exposure data from NORMAN) from both zFET and RTgill-W1 well correlated with the average RQs based on AFT LC50s. The strongest and most significant correlation was observed while comparing the AFT results with the median of combined alternative methods (zFET, RTgill-W1, ECOSAR).ConclusionsThis proposed approach combining experimental data with modeling could serve as a reliable tool for predictions of environmental risks promoting the 3R alternatives to acute fish toxicity testing.

Assessment of chemical risk associated with naturally occurring uranium in groundwater from East Khandesh, India

Assessment of chemical risk associated with naturally occurring uranium in groundwater from East Khandesh, India

Guidance for establishing and applying tolerable upper intake levels for vitamins and essential minerals.

Vitamins and essential minerals are micronutrients that are required for the normal functioning of the human body. However, they may lead to adverse health effects if consumed in excess. A tolerable upper intake level (UL) is a science-based reference value that supports policy-makers and other relevant actors in managing the risks of excess nutrient intake. EFSA's principles for establishing ULs for vitamins and minerals were originally developed by the Scientific Committee on Food in 2000. This guidance from the EFSA Panel on Nutrition, Novel Foods and Food Allergens provides an updated framework for UL assessments. A draft was published in 2022 and underwent a 2-year piloting period. The present document incorporates revisions based on the experience gained through its practical implementation. It covers aspects related to the planning of the risk assessment (problem formulation and definition of methods) and its implementation (evidence retrieval, appraisal, synthesis, integration, uncertainty analysis). As in the previous framework, the general principles developed for the risk assessment of chemicals in food are applied, i.e. hazard identification, hazard characterisation, intake assessment, risk characterisation. Specific to nutrients are their biochemical and physiological roles and the specific and selective mechanisms that maintain the systemic homeostasis and accumulation of the nutrient in the body. Such considerations must also be taken into account when conducting risk assessments of nutrients.

Hazards Analysis And Control Points In Chicken Meat

Chicken is one of the fountain sources of amino acids, vitamins (such as vitamin A), and minerals. This study's objective was to analyze the chemical and microbiological hazards and the application of treatment methods to reduce hazards. The data showed that all samples were positive for pathogenic bacteria with counts ranging from 5.39 to 6.68, 3.26 to 4.21, 6.07, to 7.30 and 6.0 to 7.46 CFU/g of staph. aureus, salmonella spp., E. coli and psychrophilic bacteria, respectively. Lactic acid has a bactericidal effect on microorganisms. The data also reflect that all raw chicken samples contain residues of norfloxacin antibiotic with a range from 1.20 to 8.10 µg/kg and significant differences between samples, while oxytetracycline was detected in 22.2% only of tested samples. Also, all samples had residues of estradiol and estrogen residues. Boiling, grilling, and freezing can reduce antibiotic and hormone residues. The elements concentrations in the livers were higher than in muscle samples. The potential chemical risk assessment of the investigated sample may lead to severe toxicological implications.

Signature analysis of high-throughput transcriptomics screening data for mechanistic inference and chemical grouping.

High-throughput transcriptomics (HTTr) uses gene expression profiling to characterize the biological activity of chemicals in in vitro cell-based test systems. As an extension of a previous study testing 44 chemicals, HTTr was used to screen an additional 1,751 unique chemicals from the EPA's ToxCast collection in MCF7 cells using 8 concentrations and an exposure duration of 6 h. We hypothesized that concentration-response modeling of signature scores could be used to identify putative molecular targets and cluster chemicals with similar bioactivity. Clustering and enrichment analyses were conducted based on signature catalog annotations and ToxPrint chemotypes to facilitate molecular target prediction and grouping of chemicals with similar bioactivity profiles. Enrichment analysis based on signature catalog annotation identified known mechanisms of action (MeOAs) associated with well-studied chemicals and generated putative MeOAs for other active chemicals. Chemicals with predicted MeOAs included those targeting estrogen receptor (ER), glucocorticoid receptor (GR), retinoic acid receptor (RAR), the NRF2/KEAP/ARE pathway, AP-1 activation, and others. Using reference chemicals for ER modulation, the study demonstrated that HTTr in MCF7 cells was able to stratify chemicals in terms of agonist potency, distinguish ER agonists from antagonists, and cluster chemicals with similar activities as predicted by the ToxCast ER Pathway model. Uniform manifold approximation and projection (UMAP) embedding of signature-level results identified novel ER modulators with no ToxCast ER Pathway model predictions. Finally, UMAP combined with ToxPrint chemotype enrichment was used to explore the biological activity of structurally related chemicals. The study demonstrates that HTTr can be used to inform chemical risk assessment by determining in vitro points of departure, predicting chemicals' MeOA and grouping chemicals with similar bioactivity profiles.

Health consequences of harmful chemicals in foods: insights from the WHO Global Burden of Foodborne Disease Study

Abstract Foods can be an important source of human exposure to harmful chemicals. Contamination can occur at any stage of the food chain; with chemicals that occur naturally or by anthropogenic pollution in the environment and during production processes from farm level to the kitchen of the consumer. The variety of chemicals in foods is broad and associated with a wide range of adverse health effects. Where toxicological risk assessment of chemicals in foods serves the purpose of protecting populations from exposure levels constituting a health concern, burden of disease methodology provides a quantitative snapshot of the current impact of chemicals on disease occurrence and population health. This allows for the comparison across hazards, health effects and foods and eventually prioritized allocation of resources to maximize health benefits. Following the advice by the World Health Organization Foodborne Disease Burden Epidemiology Reference group (WHO/FERG), WHO published in 2015 the first estimates of the global burden of foodborne disease. More than 400,000 deaths and 33 million disability-adjusted life years were estimated due to unsafe foods in 2010; the largest proportion due to foodborne pathogens, as the contribution of only 3 chemical hazards (dioxins, aflatoxin B1 and cassava cyanide) was included. WHO, once more under the advice by the re-established WHO/FERG (2021-2025), is currently working to update the 2010 estimates. Besides applying updated data and methodological improvements in managing data gaps and time series analysis, WHO’s ambition is to consider a wider range of chemicals and associated health effects for the year of 2020. In this presentation, we will share insights on the WHO estimates of the global burden of foodborne chemicals, and explore the methodological opportunities and challenges that estimating the burden of foodborne chemicals provides for informing policies.

Evaluating the performance of multi-omics integration: a thyroid toxicity case study.

Multi-omics data integration has been repeatedly discussed as the way forward to more comprehensively cover the molecular responses of cells or organisms to chemical exposure in systems toxicology and regulatory risk assessment. In Canzler etal. (Arch Toxicol 94(2):371-388. https://doi.org/10.1007/s00204-020-02656-y ), we reviewed the state of the art in applying multi-omics approaches in toxicological research and chemical risk assessment. We developed best practices for the experimental design of multi-omics studies, omics data acquisition, and subsequent omics data integration. We found that multi-omics data sets for toxicological research questions were generally rare, with no datasets comprising more than two omics layers adhering to these best practices. Due to these limitations, we could not fully assess the benefits of different data integration approaches or quantitatively evaluate the contribution of various omics layers for toxicological research questions. Here, we report on a multi-omics study on thyroid toxicity that we conducted in compliance with these best practices. We induced direct and indirect thyroid toxicity through Propylthiouracil (PTU) and Phenytoin, respectively, in a 28-day plus 14-day recovery oral rat toxicity study. We collected clinical and histopathological data and six omics layers, including the long and short transcriptome, proteome, phosphoproteome, and metabolome from plasma, thyroid, and liver. We demonstrate that the multi-omics approach is superior to single-omics in detecting responses at the regulatory pathway level. We also show how combining omics data with clinical and histopathological parameters facilitates the interpretation of the data. Furthermore, we illustrate how multi-omics integration can hint at the involvement of non-coding RNAs in post-transcriptional regulation. Also, we show that multi-omics facilitates grouping, and we assess how much information individual and combinations of omics layers contribute to this approach.

A critical review to identify data gaps and improve risk assessment of bisphenol A alternatives for human health.

Bisphenol A (BPA), a synthetic chemical widely used in the production of polycarbonate plastic and epoxy resins, has been associated with a variety of adverse effects in humans including metabolic, immunological, reproductive, and neurodevelopmental effects, raising concern about its health impact. In the EU, it has been classified as toxic to reproduction and as an endocrine disruptor and was thus included in the candidate list of substances of very high concern (SVHC). On this basis, its use has been banned or restricted in some products. As a consequence, industries turned to bisphenol alternatives, such as bisphenol S (BPS) and bisphenol F (BPF), which are now found in various consumer products, as well as in human matrices at a global scale. However, due to their toxicity, these two bisphenols are in the process of being regulated. Other BPA alternatives, whose potential toxicity remains largely unknown due to a knowledge gap, have also started to be used in manufacturing processes. The gradual restriction of the use of BPA underscores the importance of understanding the potential risks associated with its alternatives to avoid regrettable substitutions. This review aims to summarize the current knowledge on the potential hazards related to BPA alternatives prioritized by European Regulatory Agencies based on their regulatory relevance and selected to be studied under the European Partnership for the Assessment of Risks from Chemicals (PARC): BPE, BPAP, BPP, BPZ, BPS-MAE, and TCBPA. The focus is on data related to toxicokinetic, endocrine disruption, immunotoxicity, developmental neurotoxicity, and genotoxicity/carcinogenicity, which were considered the most relevant endpoints to assess the hazard related to those substances. The goal here is to identify the data gaps in BPA alternatives toxicology and hence formulate the future directions that will be taken in the frame of the PARC project, which seeks also to enhance chemical risk assessment methodologies using new approach methodologies (NAMs).

VERMEER FCM: A tool integrating exposure and hazard modelling for chemicals migrating from food contact materials

A new tool, VERMEER FCM, was developed to support the risk assessment of single organic chemicals migrating from plastic food contact materials (FCM). The freely available tool is integrated into MERLIN-Expo and has been designed in line with Regulation (EU) No 10/2011 for plastic FCM. Overall, the tool consists of three modules that allow (i) to model the migration of chemicals into food, (ii) to predict toxicological endpoints relevant to risk assessment of FCM chemicals, and (iii) to automatically check whether the chemical of interest is included in Regulation (EU) No 10/2011. To apply the VERMEER FCM tool, users need to provide information regarding the chemical(s) of interest, the FCM, the food and other parameters (e.g. contact time and temperature). The three modules can be run either separately or in combination. Migration is predicted by a recently developed migration model, whereas hazard predictions for genotoxicity, subchronic toxicity, reproductive and developmental toxicity and carcinogenicity are provided by QSAR models selected from the publicly available VEGA HUB. The major novelty of the tool is that it combines information on hazard and exposure (i.e. migration) with regulatory information. Several case studies were performed to demonstrate the application of the tool.

Computational Strategies for Assessing Adverse Outcome Pathways: Hepatic Steatosis as a Case Study.

The evolving landscape of chemical risk assessment is increasingly focused on developing tiered, mechanistically driven approaches that avoid the use of animal experiments. In this context, adverse outcome pathways have gained importance for evaluating various types of chemical-induced toxicity. Using hepatic steatosis as a case study, this review explores the use of diverse computational techniques, such as structure-activity relationship models, quantitative structure-activity relationship models, read-across methods, omics data analysis, and structure-based approaches to fill data gaps within adverse outcome pathway networks. Emphasizing the regulatory acceptance of each technique, we examine how these methodologies can be integrated to provide a comprehensive understanding of chemical toxicity. This review highlights the transformative impact of in silico techniques in toxicology, proposing guidelines for their application in evidence gathering for developing and filling data gaps in adverse outcome pathway networks. These guidelines can be applied to other cases, advancing the field of toxicological risk assessment.

Computational Tools to Facilitate Early Warning of New Emerging Risk Chemicals.

Innovative tools suitable for chemical risk assessment are being developed in numerous domains, such as non-target chemical analysis, omics, and computational approaches. These methods will also be critical components in an efficient early warning system (EWS) for the identification of potentially hazardous chemicals. Much knowledge is missing for current use chemicals and thus computational methodologies complemented with fast screening techniques will be critical. This paper reviews current computational tools, emphasizing those that are accessible and suitable for the screening of new and emerging risk chemicals (NERCs). The initial step in a computational EWS is an automatic and systematic search for NERCs in literature and database sources including grey literature, patents, experimental data, and various inventories. This step aims at reaching curated molecular structure data along with existing exposure and hazard data. Next, a parallel assessment of exposure and effects will be performed, which will input information into the weighting of an overall hazard score and, finally, the identification of a potential NERC. Several challenges are identified and discussed, such as the integration and scoring of several types of hazard data, ranging from chemical fate and distribution to subtle impacts in specific species and tissues. To conclude, there are many computational systems, and these can be used as a basis for an integrated computational EWS workflow that identifies NERCs automatically.

Using the Super-learner to Predict the Chemical Acute Toxicity on Rats

With the rapid increase in the number of commercial chemicals, testing methods regarding on median lethal dose (LD50) relying animal experiments face challenges such as high costs and ethical concerns. Classical quantitative structure-activity relationship models relying on single algorithm always lack interpretability and precision, given the complexity of the mechanisms underlying acute toxicity. To address these issues, this study has developed a predictive framework using an ensemble learning model based on Super-learner. Particularly, we first obtained LD50 data for 9,843 compounds and constructed 16 meta models using 4 molecular descriptors and machine learning algorithms. The Super-learner model performed well, achieving R² values of 0.61 and 0.64 in five-fold cross-validation and test sets, respectively, with corresponding root mean square errors of 0.55 and 0.64, significantly outperforming the results of individual model. Additionally, we incorporated data filtering and applicability domain methods, which demonstrated that the Super-learner can mitigate the impact of dataset noise to some extent. The model achieved an R² of 0.76 within an applicability domain, ensuring prediction accuracy within the chemical space. Compared to previous studies, the model developed here using Super-learner generally achieved better performance across a larger applicability domain. Finally, we has launched an online tool (http://sltox.hhra.net), allowing users to quickly predict LD50 of compounds, greatly simplifying the chemical safety assessment process. This study not only provides an effective and cost-efficient method for predicting chemical toxicity but also offers technical support and data for risk assessments of chemicals.

In vitro pharmacologic profiling aids systemic toxicity assessment of chemicals

An adapted in vitro pharmacology profiling panel (APPP) was developed that included targets used in the pharmaceutical industry alongside additional targets whose cellular functions have been linked to systemic toxicities. This panel of 83 target assays was used to profile the activities of 129 cosmetic relevant chemicals with diverse chemical structures, physiochemical properties and cosmetic use types. Internal data consistency was proved robust, as evidenced by the reproducibility between single concentration and concentration-response data and showed good concordance with data reported in the ToxCast and drug excipient datasets. We discuss how the data can be analyzed and multiple potential contexts of use illustrated by case studies, alongside other new approach methodologies, to support cosmetic chemical risk assessments that do not require data from new animal studies.

Directly measuring octanol-air partition ratios using a gas chromatography retention time (GC-RT) method

The octanol-air partition ratio (KOA) is a fundamental property used for screening chemicals for concern, depending on their potential to bioaccumulate and harm living systems. With millions of chemicals used in commerce, unfortunately, less than 800 compounds currently have experimentally measured KOA values due to limitations in traditional measurement techniques. We aimed to develop a direct gas chromatography retention time (GC-RT) method using a custom-packed column, with octanol as the stationary phase, for rapidly measuring KOA. We installed the column into a GC-mass spectrometry system and isothermally measured retention times of 15 volatile organic compounds. We calculated KOA values at experimental temperatures from the retention times and extrapolated the results to values at 25 °C using the Van't Hoff equation. Our directly measured log KOA values at 25 °C spanned 3.66 log units (0.820–4.48). Except for alcohols, our measured values agree with literature log KOA values (root mean square error, RMSE = 0.50). The discrepancy probably arose from differences in how well our method versus the literature methods capture measurement artifacts, specifically, gas-phase adsorption to the octanol phase and hydrogen bonding interactions. This proof-of-concept study demonstrates that our direct GC-RT method is promising for rapidly measuring KOA to support chemical risk assessment.

Advancing chemical safety protocols in small and medium enterprises: A comprehensive guide

Small and Medium Enterprises (SMEs) face significant challenges in managing chemical safety, often due to limited resources, inadequate infrastructure, and a lack of awareness about regulatory requirements. As chemical safety becomes increasingly critical for protecting workers, communities, and the environment, it is essential to develop tailored safety protocols for SMEs that address their unique needs. This review presents a comprehensive guide on advancing chemical safety protocols in SMEs, focusing on risk assessment, proper storage and handling of chemicals, personal protective equipment (PPE), spill prevention, and waste management. The integration of modern technologies, such as digital risk management tools, Internet of Things (IoT) sensors, and AI-driven predictive analytics, offers SMEs cost-effective solutions to enhance chemical safety. These technologies enable real-time monitoring, early warning systems for chemical hazards, and the automation of safety audits, which can significantly reduce risks and improve compliance. Additionally, fostering a strong chemical safety culture within SMEs is vital, requiring leadership commitment, employee training, and effective hazard reporting systems. Navigating regulatory frameworks and achieving compliance with limited resources presents another key challenge for SMEs. This guide highlights practical strategies for meeting safety standards, including leveraging external resources and simplifying documentation processes. Case studies showcase successful implementations of safety protocols and technologies in various SME sectors, providing insights into best practices and lessons learned. As technological advancements continue to evolve, SMEs must stay ahead by adopting innovations such as robotics, wearable safety technologies, and digital twins for chemical safety planning. This review emphasizes that a holistic approach—combining technology, policy, and workplace culture is essential for advancing chemical safety in SMEs, ensuring long-term sustainability, and safeguarding the health and well-being of workers.

Safety and sustainability by design: An explorative survey on concepts’ knowledge and application

The Safe and Sustainable by Design (SSbD) concept integrates safety and sustainability of chemicals and materials, throughout their entire life cycle and minimizes their environmental footprint. The European Commission (EC) in 2022 developed a framework to practically apply SSbD. This study investigated the knowledge on SSbD and the operationalization of such framework among the partners of the Partnership for the Assessment of Risks from Chemicals (PARC) program. Forty-one responses from 32 PARC Institutions were collected through a 21 item-online survey. Seventy-three % of the respondents had knowledge of SSbD, although only 49 % reported to have been directly engaged into SSbD projects. The EC-SSbD framework was applied by the 26 % of participants and in 47 % of cases it included a (re)design phase. With respect to the safety and sustainability, the assessment of the hazard, the human health and safety aspects in the production and processing, and the human health and environmental aspects in the final application of the chemical/material was addressed by the 74 %, 52 % and 65 % of the respondents. Lower percentages of positive responses regarded the environmental, social and economic sustainability assessment: 35 %, 20 % and 13 %, respectively. Overall, while the framework provided the necessary building blocks and opportunities for SSbD, concerted and iterative Research, Industry, and Academia efforts are necessary to develop/improve assessment methods, models and tools to make SSbD as an approach to chemical risk assessment and management to protect human health and the environment, and ensure to operate within the planetary boundaries.

Development of a comprehensive open access "molecules with androgenic activity resource (MAAR)" to facilitate risk assessment of chemicals.

The increasing prevalence of endocrine-disrupting chemicals (EDCs) and their potential adverse effects on human health underscore the necessity for robust tools to assess and manage associated risks. The androgen receptor (AR) is a critical component of the endocrine system, playing a pivotal role in mediating the biological effects of androgens, which are male sex hormones. Exposure to androgen-disrupting chemicals during critical periods of development, such as fetal development or puberty, may result in adverse effects on reproductive health, including altered sexual differentiation, impaired fertility, and an increased risk of reproductive disorders. Therefore, androgenic activity data is critical for chemical risk assessment. A large amount of androgenic data has been generated using various experimental protocols. Moreover, the data are reported in different formats and in diverse sources. To facilitate utilization of androgenic activity data in chemical risk assessment, the Molecules with Androgenic Activity Resource (MAAR) was developed. MAAR is the first open-access platform designed to streamline and enhance the risk assessment of chemicals with androgenic activity. MAAR's development involved the integration of diverse data sources, including data from public databases and mining literature, to establish a reliable and versatile repository. The platform employs a user-friendly interface, enabling efficient navigation and extraction of pertinent information. MAAR is poised to advance chemical risk assessment by offering unprecedented access to information crucial for evaluating the androgenic potential of a wide array of chemicals. The open-access nature of MAAR promotes transparency and collaboration, fostering a collective effort to address the challenges posed by androgenic EDCs.

Determination of Trace Elements Content of a Popular Traditional Herbal Medicine Used for Internal Hemorrhoids Treatment in Katsina State, Nigeria

Study’s Excerpt/Novelty Assessment of toxic metal concentrations of a widely used traditional herb in Katsina state, was carried out. Flame atomic absorption spectrophotometry and descriptive statistical analysis was employed in the research. Pb, Cr, and As were found to be beyond WHO/FAO thresholds. Full Abstract There has been an increase in the utilization of traditional herbal drugs for different medications and health care in Katsina state. This is possibly due to the growing need for complementary disease treatment, relative cheapness, availability, and wider distribution. Raw samples of a popularly used traditional herb (locally named - Dan Lambar Rimi) were purchased from local markets, prepared, and analyzed using a flame atomic absorption spectrophotometer for Pb, Cr, As, Co, Ni, and Cd concentrations. The obtained concentrations were then summarized using descriptive statistics in SPSS Version 27. The results for the elements analyzed were Ni (0.83 ± 0.15), Cd (0.20 ± 0.01), Pb (21.5 ± 6.63), As (2.10 ± 0.70), Cr (2.36 ± 0.37), and Co (1.15 ± 0.22) ppm. Cr, Pb and As concentrations were greater than the WHO/FAO threshold limits for herbal medicines, while that of Cd was within the recommended threshold. Furthermore, the concentrations of these metals (As, Cr, and Pb) were greater than the WHO/FAO acceptable threshold in 50% of the herbal samples analyzed. Therefore, these metals can pose a threat to public health, especially considering the conventional way in which this herbal medicine is used. With deliberate improvement in hygiene during its preparation prior to consumption, the risk will be brought to a minimal. Future studies should perform a detailed chemical risk assessment, especially when we look at the increase in the number of diseases of unknown etiology in the region.

Adolescent exposure to tris(1,3-dichloro-2-propyl) phosphate (TCPP) induces reproductive toxicity in zebrafish through hypothalamic-pituitary-gonadal axis disruption

Tris(1,3-dichloro-2-propyl) phosphate (TCPP), a prevalent organophosphorus flame retardant in aquatic environments, has raised significant concerns regarding its ecological risks. This study aims to explore the impacts of TCPP on the reproductive functions of zebrafish and delineate its gender-related toxic mechanisms. By assessing the effects on zebrafish of 10 mg/L TCPP exposure from 30 to 120 days post-fertilization (dpf), we thoroughly evaluated the reproductive capability and endocrine system alterations. Our findings indicated that TCPP exposure disrupted gender differentiation in zebrafish and markedly impaired their reproductive capacity, resulting in decreased egg laying and offspring development quality. Histological analyses of gonadal tissues showed an abnormal increase in immature oocytes in females and a reduction in mature sperm count and spermatogonial structure integrity in males, collectively leading to compromised embryo quality. Additionally, molecular docking results indicated that TCPP showed a strong affinity for estrogen receptors, and TCPP-treated zebrafish exhibited imbalanced sex hormones and increased estrogen receptor expression. Alterations in genes associated with the hypothalamic-pituitary-gonadal (HPG) axis and activation of the steroidogenesis pathway suggested that TCPP targets the HPG axis to regulate sex hormone homeostasis. Tamoxifen (TAM), as a competitive inhibitor of estrogen, exhibited a biphasic effect, as evidenced by the counteraction of TCPP-induced effects in both male and female zebrafish after TAM addition. Overall, our study underscored the gender-dependent reproductive toxicity of TCPP exposure in zebrafish, characterized by diminished reproductive capacity and hormonal disturbances, likely due to interference in the HPG axis and steroidogenesis pathways. These findings emphasize the critical need to consider gender differences in chemical risk assessments for ecosystems and highlight the importance of understanding the mechanisms underlying the effects of chemical pollutants on the reproductive health of aquatic species.