Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. 
Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. What was reviewed?
This peer-review synthesizes evidence on methylmercury toxicity in aquatic organisms, emphasizing how environmental modifiers (temperature, pH, salinity, dissolved organic matter) and co-pollutants (microplastics, pesticides, pharmaceuticals) shift bioavailability, uptake, and hazard. It integrates physiological, subcellular, and molecular endpoints to explain how MeHg bioaccumulates/biomagnifies and why toxicity can intensify under realistic multi-stress exposures.
Who was reviewed?
The article collates results across freshwater and marine taxa and life stages: fish (e.g., seabass, tilapia, sheepshead minnow, zebrafish), invertebrates (oysters, mussels, amphipods, rotifers, brackish water fleas), algae/diatoms, and cephalopods. It covers both controlled laboratory exposures (waterborne and dietary) and field/mesocosm evidence linking sediment, water, and biota, thus capturing trophic transfer patterns relevant to seafood safety.
Most important findings
The review confirms that MeHg binds strongly to protein thiols, crosses membranes as cysteine complexes, and bioaccumulates within organisms while biomagnifying along food webs—posing highest risk to long-lived predators. Sublethal effects span growth and reproduction constraints, impaired foraging, and transgenerational transfer. At the cell level, MeHg disrupts mitochondria, lysosomes, and lipid droplets, driving oxidative stress, lipid peroxidation, and apoptosis. Molecular signaling changes (e.g., MAPK, Nrf2-linked pathways) underpin neurotoxicity and behavioral alterations (e.g., reduced swimming, cognitive deficits).
Key implications
For HTMC, the paper argues for context-aware certification that goes beyond total Hg thresholds. Standards should (1) prioritize MeHg speciation and trophic magnification potential, (2) incorporate site and batch modifiers—temperature regime, pH/acidification status, salinity class, and sediment/DOM chemistry—because these shift bioavailability, (3) screen or document co-pollutant pressures (microplastics load, key pesticides/pharmaceuticals) where seafood is sourced, (4) weight species and life-stage susceptibility (e.g., larvae/juveniles vs adults; high-trophic fish), and (5) where feasible, integrate biomarkers (oxidative stress enzymes, lipid peroxidation, AChE) into supplier audits or R&D surveillance to detect mixture effects invisible to chemistry alone. Such measures align certification with real-world mixture ecotoxicology and help prevent underestimation of risk during warming and acidifying conditions.
Citation
Jeong, H., Ali, W., Zinck, P., Souissi, S., & Lee, J. (2024). Toxicity of methylmercury in aquatic organisms and interaction with environmental factors and coexisting pollutants: A review. Science of The Total Environment, 943, 173574. https://doi.org/10.1016/j.scitotenv.2024.173574
