Methylmercury (MeHg) is the biomagnified organometallic form of mercury that dominates dietary exposure in populations consuming fish. Methylmercury is a known developmental neurotoxicant; the literature on fetal and early-childhood exposure is extensive and forms the basis of advisories in most jurisdictions. Large predatory fish (shark, swordfish, king mackerel, bigeye tuna, tilefish) and marine mammals are the principal food-system sources. The distinction between methylmercury and total mercury is maintained throughout this wiki because methylmercury drives the health interpretation in dietary contexts; see mercury, total for the companion page.

Ufelle & Barchowsky 2021 supports this species page with textbook-level context on aquatic methylation, biomagnification, gastrointestinal absorption, blood-brain-barrier and placental transfer, fecal elimination, neurotoxicity, and treatment strategies that interrupt enterohepatic cycling. It is a toxicology source, not a food occurrence dataset.

Status

This page is a stub. Substantive content awaits corpus ingest. See methodology for the current state of the project.

Planned sections

Toxicology, typical exposure routes, fish-species concentration ranges (linked to ingredients), regulatory and advisory instruments (linked to regulations), testing methods including speciation (linked to testing), microbiome effects (linked to microbiome), vulnerable populations, open questions, and sources.

Sources

Auto-generated from source-page frontmatter. The “Used on this page for” column is populated by the orchestrator’s POPULATE-SOURCE-LEGEND action; pending entries appear as *[awaiting synthesis]*.

#CitationYearTypeUsed on this page for
1Kim et al. 2026. Combined exposure to lead, methylmercury, and cadmium impairs spatial memory and dopaminergic signaling in mouse hippocampus, Frontiers in Public Health2026Peer-reviewedMeHg data: Fifty male ICR mice were divided into five groups and exposed for 28 days via drinking water to lead (25 mg/L as lead acetate), methylmercury (10 mg/L as methylmercury chloride)…
2Lepak et al. 2026. Quantifying Depuration of Methylmercury from Fish Consumption by Travelers, Environmental Health2026Peer-reviewedMeHg depuration rates after fish consumption: half-life data and implication for exposure modelling
3Rusko et al. 2026. Risk-Benefit Assessment of Mercury, Lead, Cadmium, and Arsenic in Inland Fish from Latvian Lakes, Foods2026Peer-reviewedMeHg concentrations in freshwater fish (n=460)
4WHO 2026. GEMS/Food Contaminants database heavy-metal exports, GEMS/Food Contamination Monitoring and Assessment Programme2026Government datasetWHO GEMS/Food contaminants database: global MeHg occurrence monitoring data across food commodities
5Wu et al. 2026. Whole-Cell Biosensor for Sensitive Detection of Methylmercury in Environmental Water, Biosensors and Bioelectronics2026Peer-reviewedAnalytical sensor for MeHg detection in aqueous/environmental matrices, cited for analytical-methods context
6Auzier et al. 2025. Systematic review and spatiotemporal assessment of mercury concentration in fish from the Tapajós River Basin: implications for environmental and human health, ACS Environmental Au2025Peer-reviewedSystematic review of MeHg in fish muscle: synthesised occurrence, health effects, and exposure data
7Carter et al. 2025. Thermal Decomposition Amalgamation AAS and SALLE for Methylmercury and Total Mercury in Finfish: FDA Method Validation2025Peer-reviewedMeHg concentrations in fish muscle by AAS
8Dietz et al. 2025. Stable isotopes unveil ocean transport of legacy mercury into Arctic food webs, Nature Communications2025Peer-reviewed[awaiting synthesis]
9Jermilova et al. 2025. Assessing mercury exposure to water and fish of the Mackenzie watershed using a Bayesian network analysis, Integrated Environmental Assessment and Management2025Peer-reviewedMeHg concentrations in fish and seafood (n=1044)
10Lepak et al. 2025. Correction: Mercury Concentrations in Sport Fish from Colorado Reservoirs, PLOS ONE2025Peer-reviewedMeHg concentrations in freshwater fish
11Seyfferth et al. 2025. Concentrations and Health Implications of As, Hg, and Cd and Micronutrients in Rice and Emissions of CH4 From Variably Flooded Paddies, GeoHealth2025Peer-reviewedMeHg concentrations in rice bran (n=6)
12Taylor et al. 2025. Seafood Benefits and Contaminants: A Comprehensive Review of Health Impacts, Safety Concerns, and Risk Mitigation Strategies, Foods2025Peer-reviewedMeHg concentrations in fish and seafood
13Thoerig et al. 2025. Assessment of arsenic, cadmium, lead, mercury, and per- and polyfluoroalkyl substances concentrations in human milk and infant formula in the United States: a systematic review, American Journal of Clinical Nutrition, Vol. 122, pp. 1006-10262025Peer-reviewedSystematic review of MeHg in infant formula: synthesised occurrence, health effects, and exposure data
14Wu et al. 2025. Climate change amplifies neurotoxic methylmercury threat to Asian fish consumers, Proceedings of the National Academy of Sciences2025Peer-reviewed[awaiting synthesis]
15Zhou et al. 2025. Microbial potential to mitigate neurotoxic methylmercury accumulation in farmlands and rice, Nature Communications2025Peer-reviewed[awaiting synthesis]
16ATSDR 2024. Toxicological Profile for Mercury, U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry2024Government reportATSDR toxicological profile for mercury2024 cited for comparative context on the methylmercury page
17Barquero et al. 2024. A preliminary assessment of mercury, methylmercury and other potentially toxic elements in largemouth bass (Micropterus salmoides) from the Almadén mining district, Environmental Geochemistry and Health2024Peer-reviewed[awaiting synthesis]
18Codex 2024. Report of the 17th Session of the Codex Committee on Contaminants in Foods (REP24/CF17), Joint FAO/WHO Food Standards Programme, Codex Alimentarius Commission2024Government reportCodex CCCF 2024 deliberations: MeHg maximum level amendments and new commodity inclusions
19Eccles et al. 2024. Non-invasive biomonitoring of polar bear feces can be used to estimate concentrations of metals of concern in traditional food, PLOS ONE2024Peer-reviewed[awaiting synthesis]
20Escobar-Camacho et al. 2024. Mercury in aquatic ecosystems of two indigenous communities in the Piedmont Ecuadorian Amazon: evidence from fish, water, and sediments, Environmental Science and Pollution Research2024Peer-reviewed[awaiting synthesis]
21Kanazawa 2024. Mercury speciation in artisanal small-scale gold mining (ASGM) environments in Kenya, unknown2024Peer-reviewedMeHg data: Mercury speciation including total Hg and methylmercury (MeHg) was measured in environmental matrices (soil, water, sediment) from artisanal small-scale gold mining (ASGM) areas…
22Li et al. 2024. Global fishing patterns amplify human exposures to methylmercury, Proceedings of the National Academy of Sciences2024Peer-reviewed[awaiting synthesis]
23Tatsuta et al. 2024. Dietary intake of methylmercury by 0-5 years children using the duplicate diet method in Japan, Environmental Health and Preventive Medicine2024Peer-reviewedMeHg data: This duplicate-diet study measured total mercury and methylmercury in diets consumed by Japanese children aged 0-5 years.
24Al-Sulaiti et al. 2023. Health risk assessment of methyl mercury from fish consumption in a sample of adult Qatari residents, Environmental Science and Pollution Research2023Peer-reviewed[awaiting synthesis]
25Coe et al. 2023. Assessing the Role of the Gut Microbiome in Methylmercury Demethylation and Elimination in Humans and Gnotobiotic Mice, Archives of Toxicology, Vol. 97, pp. 2399-24182023Peer-reviewedMeHg microbial methylation/demethylation: gut microbiota roles in speciation and bioaccessibility
26Martinez-Morata et al. 2023. A State-of-the-Science Review on Metal Biomarkers, Current Environmental Health Reports, Vol. 10, No. 3, pp. 215-2492023Peer-reviewedState-of-the-science review on metal biomarkers: blood, urine, and tissue matrices for MeHg exposure assessment
27Suomi et al. 2023. Cumulative risk assessment of the dietary heavy metal and aluminum exposure of Finnish adults, Environmental Science and Pollution Research2023Peer-reviewed[awaiting synthesis]
28Bair 2022. A Narrative Review of Toxic Heavy Metal Content of Infant and Toddler Foods and Evaluation of United States Policy, Frontiers in Nutrition 9:9199132022Peer-reviewedSystematic review of MeHg in infant cereal: synthesised occurrence, health effects, and exposure data
29FDA 2022. Total Diet Study Report: Fiscal Years 2018-2020 Elements Data, U.S. Food and Drug Administration, Total Diet Study Program2022Government reportFDA Total Diet Study FY2018-2020: MeHg concentrations and estimated dietary exposures across commercial food categories
30Balali-Mood et al. 2021. Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium, and Arsenic, Frontiers in Pharmacology 12:6439722021Peer-reviewedMulti-metal toxicology review covering MeHg: oxidative stress, DNA damage, enzyme inhibition, and carcinogenic mechanisms
31Rothenberg et al. 2021. Maternal methylmercury exposure through rice ingestion and child neurodevelopment in the first three years: a prospective cohort study in rural China, Environmental Health, Vol. 20, Article 502021Peer-reviewedMeHg concentrations in rice and rice products
32Stanton et al. 2021. The Metallome as a Link Between the Omes in Autism Spectrum Disorders, Frontiers in Molecular Neuroscience 14:6958732021Peer-reviewedMeHg dyshomeostasis in neurodevelopmental conditions: metallome dysregulation context
33Zealand 2019. 25th Australian Total Diet Study, Food Standards Australia New Zealand2019Government reportFood Standards Australia New Zealand: MeHg occurrence and dietary exposure from the 25th Total Diet Study
34FDA 2017. Advice About Eating Fish — For Those Who Might Become or Are Pregnant or Breastfeeding and Children Ages 1 to 11 Years, U.S. FDA and U.S. EPA2017Government reportFDA/EPA fish consumption advice: MeHg exposure thresholds and guidance for pregnant women and vulnerable populations
35C-C et al. 2016. Methylmercury varies more than one order of magnitude in commercial European rice, Food Chemistry2016Peer-reviewedMeHg concentrations in rice flour (n=87)
36Ralston et al. 2014. Selenium Health Benefit Values: Updated Criteria for Mercury Risk Assessments, Archives of Environmental Contamination and Toxicology2014Peer-reviewedMeHg concentrations and health risk assessment in seafood
37Carroquino et al. 2013. Environmental Toxicology: Children at Risk, Encyclopedia of Sustainability Science and Technology, Chapter 11 (Springer)2013Peer-reviewedToxicology reference text on methylmercury: mechanisms of toxicity, target organs, and clinical manifestations
38Programme 2013. Minamata Convention on Mercury — Text and Annexes (2024 Edition), United Nations Environment Programme, Secretariat of the Minamata Convention on Mercury2013Government reportMinamata Convention on Mercury (2013): global treaty framework, mercury phase-down schedules, and food safety regulatory context
39EFSA 2012. Scientific Opinion on the Risk for Public Health Related to the Presence of Mercury and Methylmercury in Food, EFSA Journal 2012;10(12):29852012Government reportEFSA 2012 scientific opinion on MeHg: PTWI of 1.3 µg/kg bw/week, neurological-endpoint dose-response, and dietary exposure from fish
40Farina et al. 2011. Mechanisms of Methylmercury-Induced Neurotoxicity: Evidence from Experimental Studies, Life Sciences 89(15-16):555-5632011Peer-reviewedMeHg toxicological mechanisms, target organ effects, and dose-response evidence
41JECFA 2011. Evaluation of Certain Contaminants in Food: Seventy-second Report of the Joint FAO/WHO Expert Committee on Food Additives (Lead, among others), WHO Technical Report Series 9592011Government reportJECFA 72nd evaluation of lead: BMDL01 approach, withdrawal of PTWI, context for MeHg comparative regulatory standards
42JECFA 2004. Evaluation of Certain Food Additives and Contaminants (Methylmercury), 61st Meeting of JECFA, WHO Technical Report Series 9222004Government reportJECFA 61st evaluation of MeHg: PTWI of 1.6 µg/kg bw/week for neurological endpoints and fish-consumption exposure basis
43EPA 2001. Methylmercury (MeHg) — IRIS Chemical Assessment Summary, U.S. Environmental Protection Agency, Integrated Risk Information System2001Government reportEPA IRIS toxicological review for methylmercury: oral reference dose, inhalation unit risk, and dose-response derivation
44Codex 1995. General Standard for Contaminants and Toxins in Food and Feed (CXS 193-1995), Codex Alimentarius (Joint FAO/WHO Food Standards Programme)1995Government reportCodex General Standard for Contaminants (CXS 193): MeHg maximum levels across food commodities