{
  "slug": "glyphosate-roundup-cancer",
  "question": "What are the odds that dietary glyphosate (Roundup) exposure will give you cancer?",
  "category": "cancer",
  "tags": [
    "food"
  ],
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Glyphosate is the most-used herbicide in world agriculture and the active ingredient in Roundup. The IARC 2015 reclassification of glyphosate as \"probably carcinogenic to humans\" (Group 2A), the multi-billion-dollar Monsanto/Bayer verdict against the company in Johnson v. Monsanto (2018), and a steady stream of \"Roundup found in your cereal\" press cycles have cemented public concern. Many consumers treat any detectable glyphosate residue on oats, wheat or chickpeas as a meaningful cancer risk and purchase organic specifically to avoid it. Surveys consistently rank pesticides among the top food-safety concerns of US adults.\n",
    "rough_estimate": "46% of US adults rank pesticides as a top-3 food safety concern (IFIC 2025)",
    "kind": "survey",
    "survey_source": {
      "title": "IFIC 2025 Food & Health Survey -- 46% of US adults rank pesticides and pesticide residues as a top-3 food-safety concern",
      "publisher": "International Food Information Council (IFIC)",
      "url": "https://ific.org/media/confidence-in-food-safety-hits-record-low/",
      "year": 2025
    }
  },
  "native": {
    "display": "~99.9% of US dietary intake estimates fall below 1/1000 of EFSA's 0.5 mg/kg/day acceptable daily intake; no statistically significant cancer association in the largest applicator cohort",
    "numerator": 1,
    "denominator": 1000000,
    "unit": "per dietary lifetime (attributable cancer harm, US adult)",
    "population": "US adults consuming conventional produce, grains and processed foods"
  },
  "normalized": {
    "lifetime_us_adult": 0.000001,
    "display": "~1 in 1,000,000 or less lifetime (US adult dietary)",
    "log_value": -6,
    "assumptions": "The US adult lifetime dietary cancer attributable to glyphosate is set as a conservative 1-in-1,000,000 placeholder, the same floor used by `pesticide-residue-food`, because no dietary-exposure cohort has detected a cancer signal and applicator-cohort evidence (Andreotti et al. 2018, JNCI, N=54,251 -- the largest prospective study available) reports no association between glyphosate use and non-Hodgkin lymphoma (rate ratio 0.87, 95% CI 0.64-1.20 for highest exposure quartile vs never users, p-trend 0.95). Typical US dietary intake estimates from the FDA Total Diet Study are roughly 1/1000 of EFSA's acceptable daily intake of 0.5 mg/kg/day. The IARC 2015 Group 2A classification (Monograph 112) rested on \"limited\" human evidence from occupational case-control studies and \"sufficient\" evidence in laboratory rodents; EPA (2020 interim review), EFSA (2023 peer review), ECHA (2022 RAC opinion), Health Canada (2017 re-evaluation), and Australian APVMA have each concluded that glyphosate is not likely to be carcinogenic to humans at expected exposure levels. The 1-in-1,000,000 figure is a conservative ceiling acknowledging the IARC dissent and possible low-dose effects not yet measurable; the true dietary figure may be effectively zero. The wide uncertainty band reflects this institutional disagreement, not measured variability.\n",
    "uncertainty": {
      "low": 1e-7,
      "high": 0.00001
    },
    "scope": "us_adult_lifetime"
  },
  "sources": [
    {
      "url": "https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate/",
      "title": "IARC News: Q&A on Glyphosate",
      "publisher": "International Agency for Research on Cancer (IARC), WHO",
      "source_type": "govt_report",
      "statistic": "IARC Monograph Volume 112 (March 2015) classified glyphosate as Group 2A, \"probably carcinogenic to humans\", based on limited evidence in humans for non-Hodgkin lymphoma and sufficient evidence in laboratory animals.",
      "excerpt": "Glyphosate was classified as \"probably carcinogenic to humans\" (Group 2A) based on \"limited\" evidence of cancer in humans from real-world exposures that actually occurred, \"sufficient\" evidence of cancer in experimental animals from studies of pure glyphosate, and \"strong\" evidence for genotoxicity, both for pure glyphosate and for glyphosate formulations.\n",
      "source_date": "2016-03-01",
      "source_accessed": "2026-05-30",
      "archive_url": "http://web.archive.org/web/20260529140301/https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate/",
      "calculation_notes": "The IARC Group 2A classification is a hazard-identification, not a risk-quantification. It states that the agent has the potential to cause cancer under some exposure conditions, not that any particular exposure level produces a measurable cancer rate. The dietary cancer probability for a typical consumer is not computable from this source alone. Cited here to anchor the IARC half of the institutional split and to ensure the entry is honest about the strongest evidence in the \"concerning\" direction.\n",
      "independence_note": "IARC's evaluation drew on ~1,000 publicly available studies via an independent working group with conflict-of-interest screening. The working-group methodology is institutionally distinct from EPA, EFSA and ECHA cancer-classification processes, which weight the evidence base differently (notably by including registrant-submitted studies not always in IARC's review universe).\n"
    },
    {
      "url": "https://www.epa.gov/ingredients-used-pesticide-products/glyphosate",
      "title": "Glyphosate (Ingredient Used in Pesticide Products)",
      "publisher": "US Environmental Protection Agency",
      "source_type": "govt_report",
      "statistic": "EPA Interim Registration Review (2020) concluded that glyphosate is not likely to be carcinogenic to humans at exposure levels expected from approved uses; review covered 15 acceptable carcinogenicity studies, more than IARC's 8 animal studies.",
      "excerpt": "\"EPA concluded that glyphosate is not likely to be carcinogenic to humans.\" EPA further notes that its position is based on \"a more extensive dataset of studies\" than IARC reviewed.\n",
      "source_date": "2022-08-01",
      "source_accessed": "2026-05-30",
      "archive_url": "http://web.archive.org/web/20260531020904/https://www.epa.gov/ingredients-used-pesticide-products/glyphosate",
      "calculation_notes": "EPA's Interim Registration Review for glyphosate (2020) and subsequent defenses of that decision form the institutional counterweight to IARC. Like IARC the conclusion is hazard-level rather than a quantitative cancer rate, but the framing -- \"not likely carcinogenic to humans\" at expected exposures -- bears directly on the dietary consumer scope this entry concerns. Used jointly with EFSA below to establish that the regulatory consensus across the largest assessment bodies is non-carcinogenic at dietary levels.\n",
      "independence_note": "EPA's review universe includes registrant-submitted carcinogenicity studies that IARC excluded; EPA and IARC analysed substantially overlapping but not identical study sets. EFSA's evaluation is institutionally separate and reaches a similar conclusion via a separate review pipeline.\n"
    },
    {
      "url": "https://www.efsa.europa.eu/en/news/glyphosate-no-critical-areas-concern-data-gaps-identified",
      "title": "Glyphosate: No Critical Areas of Concern; Data Gaps Identified",
      "publisher": "European Food Safety Authority (EFSA)",
      "source_type": "govt_report",
      "statistic": "EFSA July 2023 peer review concluded no critical areas of concern for human, animal or environmental health from glyphosate; relied on ECHA RAC 2022 opinion that glyphosate does not meet criteria for classification as carcinogenic, mutagenic or reprotoxic.",
      "excerpt": "EFSA's peer review concluded there were \"no critical areas of concern\" regarding glyphosate's impact on human health, animal welfare, or environmental safety. EFSA relied on ECHA's classification finding that glyphosate \"did not meet the scientific criteria to be classified as a carcinogenic, mutagenic or reprotoxic substance.\"\n",
      "source_date": "2023-07-06",
      "source_accessed": "2026-05-30",
      "calculation_notes": "EFSA's 2023 conclusion is the third major regulatory data point against IARC's Group 2A classification (after EPA 2020 and ECHA 2022 RAC). It does not produce a dietary cancer probability either, but strengthens the case that across the major Western regulators the consensus on the dietary-consumer cancer question converges on \"no measurable increase\". Combined with Andreotti below, this is the basis for the 1-in-1,000,000 conservative placeholder rather than a higher figure.\n",
      "independence_note": "EFSA's peer review draws on ECHA's hazard classification and on member-state rapporteur assessments. Methodologically independent of both EPA (different review pipeline, different study weighting) and IARC (different evaluation rules; EFSA reviews regulatory dossiers including industry submissions, IARC focuses on publicly available studies).\n"
    },
    {
      "url": "https://academic.oup.com/jnci/article/110/5/509/4590280",
      "title": "Glyphosate Use and Cancer Incidence in the Agricultural Health Study",
      "publisher": "Journal of the National Cancer Institute (Andreotti et al.)",
      "source_type": "peer_reviewed",
      "statistic": "Prospective US cohort, N=54,251 licensed pesticide applicators (44,932 glyphosate users; 5,779 incident cancer cases). No association between glyphosate use and non-Hodgkin lymphoma overall or any NHL subtype (rate ratio 0.87, 95% CI 0.64-1.20 for highest exposure quartile vs never users, p-trend 0.95).",
      "excerpt": "\"In this large, prospective cohort study, no association was apparent between glyphosate and any solid tumors or lymphoid malignancies overall, including NHL and its subtypes.\"\n",
      "source_date": "2018-02-08",
      "source_accessed": "2026-05-30",
      "archive_url": "http://web.archive.org/web/20260307215642/https://academic.oup.com/jnci/article/110/5/509/4590280",
      "calculation_notes": "The Agricultural Health Study is the largest prospective cohort of licensed applicators with quantitative glyphosate-exposure data. It addresses the cancer hypothesis most prominently raised by IARC (non-Hodgkin lymphoma) and reports no association at any exposure quartile. A nominally elevated acute-myeloid-leukemia signal in the highest exposure quartile (rate ratio 2.44, 95% CI 0.94-6.32) is the one residual finding worth flagging and is not statistically significant. This is the strongest single piece of dietary-relevant negative evidence: applicators have orders-of-magnitude higher exposure than dietary consumers, and the null at the high end implies a very small ceiling on consumer-level dietary harm.\n",
      "independence_note": "The Agricultural Health Study is a long-running NCI/NIEHS/EPA collaboration tracking ~89,000 farmers and spouses; independent of IARC, EPA classification reviews and EFSA peer reviews. The Andreotti 2018 update extended follow-up by ~12 years relative to the 2005 analysis that contributed to IARC's evaluation.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "Pesticide residue on conventional produce (lifetime, US adult)",
      "lifetime_us_adult": 0.000001
    },
    {
      "label": "Baseline non-Hodgkin lymphoma (lifetime, US adult)",
      "lifetime_us_adult": 0.0214
    },
    {
      "label": "Death from food poisoning (lifetime, US adult)",
      "lifetime_us_adult": 0.000537
    }
  ],
  "regional_breakdown": [
    {
      "region": "US adult dietary consumer (FDA Total Diet Study + Andreotti 2018)",
      "probability": 0.000001,
      "notes": "intake typically ~1/1000 of EFSA ADI; placeholder floor based on null applicator-cohort finding extrapolated downward by orders of magnitude"
    },
    {
      "region": "EU adult dietary consumer (EFSA 2023 dietary risk assessment)",
      "probability": 5e-7,
      "notes": "modestly lower glyphosate residue exposure than US estimates; EFSA dietary risk assessment found no consumer concern at approved-use levels"
    },
    {
      "region": "Occupational licensed applicator (Agricultural Health Study cohort, high exposure quartile)",
      "probability": 0.025,
      "notes": "baseline lifetime NHL risk ~2.14%; Andreotti 2018 found RR 0.87 (not statistically elevated) for highest glyphosate exposure quartile -- so the applicator subgroup tracks the baseline rate rather than dramatically exceeding it; scope is occupational, not dietary"
    }
  ],
  "personal_factor_multipliers": [
    {
      "factor": "Occupational licensed pesticide applicator (mixing, loading or spraying glyphosate)",
      "multiplier": 5,
      "notes": "Applicator exposure via dermal and inhalation routes runs orders of magnitude higher than dietary exposure. Andreotti et al. 2018 reports no statistically significant cancer association at any exposure quartile, including the highest, but the IARC dissent and the qualitatively elevated (non-significant) acute-myeloid-leukemia signal in the high quartile warrant a meaningful multiplier here. The figure does not extrapolate Zhang 2019 to a lifetime number; it represents the plausibility ceiling implied by the evidence base taken as a whole.\n"
    },
    {
      "factor": "Hobby gardener using glyphosate-formulation sprays heavily (multiple applications per year without PPE)",
      "multiplier": 2,
      "notes": "A heavy hobby user does not approach occupational applicator exposure but does exceed typical dietary intake by a wide margin. See `gardening-without-ppe` for the broader gardening-exposure perspective; that entry pegs glyphosate at roughly 1e-6 for a typical hobbyist with normal use patterns.\n"
    },
    {
      "factor": "Heavy consumer of US wheat-, oat- and pulse-based products (commodities with higher pre-harvest desiccation residues)",
      "multiplier": 1.5,
      "notes": "EWG and FDA Total Diet Study residue surveys consistently identify oats and pulses as the highest-residue commodities in the US food supply because of pre-harvest desiccation practices. Even at the upper end of consumption, intake remains well below the EFSA ADI; the modest multiplier reflects exposure rather than measured cancer risk.\n"
    },
    {
      "factor": "Exclusively organic diet (low-residue baseline)",
      "multiplier": 0.3,
      "notes": "Certified-organic food has substantially lower glyphosate residue levels but not zero (atmospheric drift, contamination). The reduction in already-very-low dietary exposure is real but the absolute risk difference at consumer scope is small.\n"
    }
  ],
  "short_label": "Glyphosate & cancer",
  "myth_framing": "overrated",
  "outcome_severity": "serious_harm",
  "exposure_pattern": "cumulative",
  "outcome_type": "chronic_illness",
  "valence": "negative",
  "caveats": "This entry addresses dietary glyphosate exposure for a US adult consuming conventional produce, grains and processed food, and its plausible attributable cancer risk. It does not cover occupational applicator exposure beyond the multiplier above, ecological effects (pollinators, amphibians, aquatic invertebrates), herbicide-resistance evolution in weed populations, or non-cancer endpoints (kidney function, endocrine effects, microbiome) which remain active research areas without population-scale consensus. The 1-in-1,000,000 figure is a conservative ceiling, not a measured rate -- no dietary-exposure cohort has detected a cancer signal at typical consumer exposures, and the largest applicator cohort (Andreotti 2018, N=54,251) reports null at all exposure quartiles. The IARC Group 2A vs EPA/EFSA/ECHA/Health Canada non- carcinogen split is real and load-bearing; this entry sides with the larger-cohort-weighted regulatory consensus for the dietary scope while flagging the IARC dissent in the assumptions. Zhang et al. 2019 meta- analysis (a frequently cited counterpoint) is methodologically controversial because of its high-exposure-only subgroup focus and was not used to derive a lifetime number here; the literature on its conclusions remains genuinely split. If long-term US dietary cohort data eventually report a signal, this entry will be revised.\n",
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    "d2": 5,
    "d3": 3,
    "d4": 4,
    "d5": 4,
    "d6": 4,
    "d7": 5,
    "d8": 5,
    "avg": 4.375,
    "scored_by": "claude-code-8d",
    "scored_at": "2026-05-30",
    "methodology_version": "1.2"
  },
  "reviewer": "8d-eval-2026-05-30",
  "last_reviewed": "2026-05-30",
  "reviewed": true,
  "generated_at": "2026-05-30",
  "image": {
    "alt": "A single stalk of wheat against a pale neutral background, flat vector illustration."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single",
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