Open research questions in Environmental Toxicology and Ecotoxicology

What the literature leaves open

• Identification of bioaccumulative chemicals has largely relied on models and empirical data describing bioaccumulation of nonionizable organic chemicals in fish, but bioaccumulation research has remained understudied in other aquatic taxa, particularly for ionizable organic chemicals.

  pH influences on kinetics, bioconcentration, and internal disposition of diphenhydramine, a weakly basic pharmaceutical, in signal crayfish ( Pacifastacus leniusculus ) · 2026 · DOI

• By applying Emerging Hotspot Analysis alongside the Space–Time Cube framework, persistent, intensifying, and newly emerging clusters of industrial discharge activity were systematically identified, addressing an important gap in understanding how reported surface-water releases vary through space and time in this region.

  Spatiotemporal Toxicity: Emerging Patterns of Industrial Water Pollution in the Coosa River Watershed, USA (2000–2020) · 2026 · DOI

• The highest neonicotinoid concentrations reported in Ontario row crop sites (0.23 µg/L total) are substantially lower than California concentrations reported by Starner and Goh; comparative geographic sampling across multiple agroecological regions with standardized methods and detection limits is needed to characterize how regional agricultural practices affect neonicotinoid contamination available to barn swallows.

  Quantifying insecticide exposure across an agricultural landscape gradient using barn swallows as a wildlife indicator · 2026 · DOI

• Urban sources of aquatic neonicotinoid contamination (from turf and ornamental imidacloprid applications) have been identified but not systematically quantified or compared to agricultural sources in the context of barn swallow habitat use; integrated sampling across urban-rural landscape gradients is required to determine the relative contribution of each source to overall wildlife exposure.

  Quantifying insecticide exposure across an agricultural landscape gradient using barn swallows as a wildlife indicator · 2026 · DOI

• Future research should investigate the long-term effects of glyphosate exposure on aquatic organisms. Future research should also explore the potential mitigation strategies for reducing the toxicity of glyphosate.

  Effects of Acute Toxicity of Analytical Grade Glyphosate (AGG) herbicide on biochemical metabolic indices of Africa Catfish (Clarias gariepinus) · 2026 · DOI

• The gap in the study is the lack of understanding of the effects of glyphosate on aquatic organisms. The study highlights the need for further research on the toxicity of glyphosate to non-targeted living organisms.

  Effects of Acute Toxicity of Analytical Grade Glyphosate (AGG) herbicide on biochemical metabolic indices of Africa Catfish (Clarias gariepinus) · 2026 · DOI

• The effects of cobalt nanoparticles on endocrine disruption in fish are not well understood. There is a need to develop novel strategies to mitigate the effects of environmental stresses on fish reproduction.

  Cobalt nanoparticles protect against endocrine disruption in response to multiple abiotic stresses in fish · 2026 · DOI

• Across this set, heavy-metal bioaccumulation in fish is evaluated only in fresh or live-caught specimens from marine and freshwater ecosystems; no study measures trace-element concentrations in dried-fish products, where moisture loss and microbial/chemical degradation during drying may alter bioavailability and residue levels relative to fresh tissue.

  Organ-specific bioaccumulation of trace elements in commercial marine finfish from the South Andaman Islands and associated human health risk assessment · 2026 · DOI

• Future research should investigate the effects of heavy metals and explosives on other aquatic organisms. Future research should consider the cumulative properties of toxicants and their long-term effects on aquatic ecosystems.

  Influence of water pollution with heavy metals and explosives on Daphnia magna (Straus, 1820) in model experiments · 2026 · DOI

• There is a gap in understanding the long-term impact of background concentrations of heavy metals on aquatic organisms. Prior work has focused on acute experiments, leaving a gap in understanding chronic effects.

  Influence of water pollution with heavy metals and explosives on Daphnia magna (Straus, 1820) in model experiments · 2026 · DOI

• There is a need for ecotoxicological studies using native species in the Amazon region. The study identifies a gap in the understanding of the impacts of neonicotinoids on A. bimaculatus.

  Neonicotinoid insecticide thiamethoxam compromises early larval development of the Amazonian tetra fish Astyanax bimaculatus (Linnaeus, 1758) · 2026 · DOI

• Further studies can evaluate the radiological and toxicological risks of consuming fish from other regions and environments. The study's methods can be applied to other fish species and environments to assess radiological and toxicological risks. Future research can investigate the effects of cooking and processing on the radiological and toxicological risks of consuming fish.

  Assessment of Committed Effective Dose and Health Risk Index in Commonly Consumed Fish from Cold Rooms in Akure, Nigeria · 2026 · DOI

• There is a need to assess the radiological and toxicological risks of consuming fish from cold storage facilities in Akure, Nigeria. Prior work has not evaluated the activity levels of U-238, Th-232, and K-40, and concentrations of ten heavy metals in fish species from this region.

  Assessment of Committed Effective Dose and Health Risk Index in Commonly Consumed Fish from Cold Rooms in Akure, Nigeria · 2026 · DOI

• There is a lack of understanding of thiram's toxicity in pangasius fish. The genotoxicity and oxidative stress induction of thiram in fish are not well understood.

  Integrated assessment of thiram toxicity in pangasius fish: Erythrocytic abnormalities, gill and intestinal defense mechanisms, and genotoxicity · 2026 · DOI

• There is a need to understand the mechanisms involved in toxin accumulation and depuration in scallops.

  Influence of organs, body size and growth on domoic acid depuration in the king scallop, Pecten maximus · 2026 · DOI

• The paper mentions the need for further investigation into post-fish handling and land-use activities. The study highlights the importance of monitoring trace elements in fish and their potential risk to human health.

  Monitoring and Human Health Assessment of Trace Elements in Fresh and Dry Fish From Lake Kariba, Siavonga, Zambia · 2026 · DOI

• There is a need for new biomarkers for assessing freshwater pollution. The effects of heavy metal contamination on kidney histopathology in M. gulio are not well understood. There is a lack of research on the use of kidney histopathological alterations as a biomarker for pollution monitoring.

  Evaluation of histopathological alterations in the kidney of keting catfish (Mystus gulio) as a biomarker of pollution in the Welang, Gembong, and Rejoso rivers, Pasuruan, East Java, Indonesia · 2026 · DOI

• The study identifies the challenge of detecting toxic elements in the embryo samples, with most elements remaining below the limit of detection. The study also identifies the challenge of minimizing matrix effects in the GC-MS analysis. The study references the need for careful sample preparation to avoid contamination and ensure accurate results.

  Polycyclic aromatic hydrocarbons, toxic and potentially toxic elements in Pelophylax esculentus complex embryos from the UNESCO-Protected Drava River Floodplain (Croatia) · 2026 · DOI

• This should be taken into consideration when conducting further studies on the issue of climate change and simultaneous increase of dissolved TNT in the water.

  Elevated water temperatures enhance 2,4,6-trinitrotoluene induced stress response of carbonyl reductase in blue mussels (Mytilus edulis): Another environmental impact of climate change? · 2026 · DOI

• The study aims to address the gap in understanding the chronic toxicity of benzyl alcohol in aquatic ecosystems. The use of biochemical and molecular biomarkers is proposed to fill the gap in sensitive indicators of chronic toxic stress in freshwater invertebrates.

  Oxidative Stress Responses and Antioxidant Gene Regulation in Daphnia pulex Following Chronic Benzyl Alcohol Exposure · 2026 · DOI

• The paper identifies the need to understand the mechanisms of protection against waterborne pollutants. It also highlights the importance of sustainable and viable protein sources for the growing global population.

  Dietary banana peels modulate waterborne oxyfluorfen-induced hepatotoxicity in Nile tilapia (Oreochromis niloticus) via regulation of redox homeostasis and ER stress signaling · 2026 · DOI

• One of the challenges is the potential for cadmium to accumulate in snails even after the water concentration is reduced. Another challenge is the need for further research to fully understand the mechanisms by which shell dust reduces cadmium bioavailability and bioaccumulation.

  Can Shell Dust Amend Cadmium-Contaminated Water? Inference from the Bioavailability and Bioaccumulation in the Freshwater Snail Physella Acuta · 2026 · DOI

• Heavy-metal and pesticide studies in this set focus on single or few fish species per location; none systematically compares contamination profiles across multiple dried-fish species (e.g., anchovy, herring, small pelagics, catfish, tilapia) from the same polluted region to identify species-specific bioaccumulation or dietary exposure pathways relevant to subsistence and commercial dried-fish consumers.

  Organ-specific bioaccumulation of trace elements in commercial marine finfish from the South Andaman Islands and associated human health risk assessment · 2026 · DOI

• Nigerian assessments almost universally determine total element concentrations, then apply toxicity reference values derived for specific chemical species: an inorganic arsenic reference dose applied to total arsenic that is predominantly organic in marine organisms, a methylmercury reference dose applied to total mercury, and oral cancer slope factors applied to nickel for which oral carcinogenicity has not been…

  Arsenic, Mercury and Nickel in Nigerian Seafood: A Critical Appraisal of Exposure Estimation, Speciation and Risk Characterisation · 2026 · DOI

• The study identifies a gap in the assessment of PAHs and toxic elements in European green frog embryos from the Drava River Floodplain area. The study aims to fill this gap by providing a preliminary assessment of the pollution profile of the area.

  Polycyclic aromatic hydrocarbons, toxic and potentially toxic elements in Pelophylax esculentus complex embryos from the UNESCO-Protected Drava River Floodplain (Croatia) · 2026 · DOI

Most-cited papers in Environmental Toxicology and Ecotoxicology

• Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. · Environmental Health Perspectives · 1998 · 2,703 citations
• Fish Intake, Contaminants, and Human Health · JAMA · 2006 · 1,587 citations
• Manufactured Nanomaterials (Fullerenes, C 60 ) Induce Oxidative Stress in the Brain of Juvenile Largemouth Bass · Environmental Health Perspectives · 2004 · 1,150 citations
• Methylmercury Exposure and Health Effects in Humans: A Worldwide Concern · AMBIO · 2007 · 982 citations
• Effects of Environmental Methylmercury on the Health of Wild Birds, Mammals, and Fish · AMBIO · 2007 · 846 citations
• Vitellogenesis as a biomarker for estrogenic contamination of the aquatic environment. · Environmental Health Perspectives · 1995 · 627 citations
• Environmental occurrence, abundance, and potential toxicity of polychlorinated biphenyl congeners: considerations for a congener-specific analysis. · Environmental Health Perspectives · 1989 · 558 citations
• Predicted Exposures to Steroid Estrogens in U.K. Rivers Correlate with Widespread Sexual Disruption in Wild Fish Populations · Environmental Health Perspectives · 2006 · 472 citations
• Health effects assessment for environmental perchlorate contamination: the dose response for inhibition of thyroidal radioiodine uptake in humans. · Environmental Health Perspectives · 2002 · 397 citations
• Acute Toxicity of the Tire Rubber-Derived Chemical 6PPD-quinone to Four Fishes of Commercial, Cultural, and Ecological Importance · Environmental Science & Technology Letters · 2022 · 397 citations

Most recent work

• Increasing applied pesticide toxicity trends counteract the global reduction target to safeguard biodiversity · Science · 2026
• Integrated analysis of detoxification pathways and hepatotoxicity of butylated hydroxytoluene (BHT) in the Manila clam (Ruditapes philippinarum) · Ecotoxicology and Environmental Safety · 2026
• Heavy metal infiltration in coastal sediments: Bioaccumulation pathways and toxicological repercussions on Perinereis aibuhitensis · Marine Pollution Bulletin · 2026
• Tissue-Specific Accumulation of Heavy Metals and Oxidative Stress in Atlantic Bonito (Sarda sarda, Bloch 1793) Marketed in Kütahya · Biology · 2026
• A machine learning-based QSAR model for predicting toxicity of commercial pesticides to Eisenia fetida · Ecotoxicology and Environmental Safety · 2026
• Common birds have higher abundances in croplands with lower pesticide purchases · Proceedings of the Royal Society B Biological Sciences · 2026
• Propylparaben exposure induces hematobiochemical alterations, genotoxicity oxidative stress and apoptosis in Labeo rohita · Veterinary Research Communications · 2026
• Mitochondrial Gene Expression as a Novel Biomarker for Detecting and Discriminating Neurotoxic Pesticide Exposure in Ramulus phyllodeus (Chen & He, 2008) · Insects · 2026
• Ecotoxicological responses to 6PPD-Q: Oxidative stress, gene expression dysregulation, and transcriptomic alterations in Eisenia fetida · Applied Soil Ecology · 2026
• Confronting pesticide exposure predictions from different models to observations from a monitoring study in small freshwater streams in Germany · Environment International · 2026

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