Potatoes

Completeness scorecard

Deterministic gap audit — no score is composite, no cell is LLM-judged. Each chip is re-derivable by re-running tools/evidence/build-ingredient-scorecard.mjs. review: residuals and missing data are worked autonomously via data/evidence/ingredient-scorecard-review-flags.csv and wiki/completeness-gaps.md.

Potatoes are identified by EFSA Cd 2009 as one of the population-level dietary cadmium contributors, placed in a joint “starchy roots and potatoes” category alongside other root vegetables. The commodity is distinct from the root-vegetables-for-babies category that the FDA CTZ Pb guidance treats under a dedicated 20 ppb action level.

Heavy metal contamination profile

Per-analyte snapshot derived from the machine-readable contamination_profile in the frontmatter above. data gap indicates the literature has been reviewed for this commodity-analyte combination and no usable occurrence data was found (a finding, not a placeholder). The Key sources column shows the top 2-3 contributing sources by year and sample size, with numbered wikilink aliases.

Synthesis basis and censoring treatment

The lead, chromium, and uranium cells were resynthesized on 2026-06-11 on a raw-potato wet-weight basis, the form in which the commodity enters the ingredient supply chain. The FDA Total Diet Study reports this matrix as cooked Food 136 “Potato, peeled, boiled”; its values are carried as a corroborating as-consumed anchor rather than the headline basis, because most primary occurrence literature reports raw potato tubers and because peeling-plus-boiling removes a small fraction of the metal load relative to the raw tuber.

Values below the analytical limit of detection or quantification are treated as left-censored, not as measured zeros. The earlier profile reported lead, chromium, and uranium at typical and 95th-percentile values of zero. Those figures were an artifact of the FDA Total Diet Study composites, in which every sample (or all but one) fell below the reporting limit and the reported zeros were pooled as literal zeros. For lead, FDA reported all 27 composites below the 4 µg/kg reporting limit; for uranium, all 27 below the 1 µg/kg reporting limit; for chromium, 26 of 27 below the 50 µg/kg reporting limit with a single detect at 63 µg/kg (FDA 2022). The resynthesis replaces the literal zeros with a left-censored floor at the FDA reporting limit and recovers the upper distribution from primary raw-potato occurrence literature, in which lead and chromium are low but non-zero in tuber flesh.

The lead floor is set at the FDA 4 µg/kg reporting limit. The central distribution rests on the long-term UK Nafferton field trials (Rempelos et al. 2023, potato-tuber Pb main-effect means 21 to 31 µg/kg fresh weight) and on the Uruguayan wholesale-market survey (Sixto et al. 2023, whole-potato pools mostly non-detect or below the limit of quantification on a fresh-weight basis). The 95th-percentile anchor of 200 µg/kg is the Babol, Iran retail potato mean (Abdolahpour et al. 2023, potato Pb 0.20 mg/kg fresh weight), which exceeds the Iranian national 0.1 mg/kg non-leafy limit and is drawn from a single agricultural plain with documented industrial and irrigation pressure. Industrial-zone potato exceeds this by one to two orders of magnitude and is treated as a stratified outlier rather than folded into the percentile: the Bogura, Bangladesh survey (Samma et al. 2024) reports potato lead of 5,970 to 25,770 µg/kg dry weight across the most-industrialized northern district, with a Pb contamination factor above 6, and is direct evidence only for produce grown in or near that kind of industrial soil-loading context.

Chromium is reported as total chromium only; no potato hexavalent-chromium measurement exists in the corpus, and Cr-VI is never inferred from total chromium. The chromium floor is the FDA 50 µg/kg reporting limit. The central fresh-weight distribution rests on the Polish plant-food survey (Reczajska et al. 2005, potato n=24, range below 1 to 11 µg/kg fresh weight, mean 3, median 4, 90th percentile 9 µg/kg). The 95th-percentile anchor of 63 µg/kg is the single FDA detect, the highest fresh-weight-comparable potato value in the corpus. Polluted-irrigation and industrial tubers run substantially higher on a dry-weight basis and are stratified rather than pooled: the tuber review (Stasinos et al. 2014) compiles Thiva-basin Greek tuber total chromium of 1.9 to 4.1 mg/kg dry weight and a Latvian allotment mean of 0.16 mg/kg dry weight, and the Bogura survey reports vegetable-level total chromium below the detection limit to 5.44 mg/kg dry weight in an industrial district. These dry-weight polluted-region values are not basis-comparable to the fresh-weight percentile and are recorded as a separate contamination stratum, holding chromium confidence at low.

Uranium is recorded as a reviewed data gap: the only potato uranium measurement in the corpus is the fully censored FDA Total Diet Study cell (all 27 composites below the 1 µg/kg reporting limit), and no primary raw-potato source reports an extractable quantitative uranium value, so no distribution is published. The earlier non-zero-confidence zero was the same censoring artifact and is withdrawn.

Why this commodity accumulates cadmium

Potatoes are tubers that form and mature in direct soil contact, with cadmium uptake driven by soil cadmium concentration, soil pH, and tuber surface area. Cadmium concentrations tend to be modestly higher in potato peel than in potato flesh, though the gradient is less pronounced than for some other root-crop commodities. Regional variation in finished-potato cadmium reflects soil cadmium in the growing region, with phosphate-fertilizer-amended soils and hotspot areas producing elevated potato cadmium.

Ranges by source, region, and variety

Pending ingest of commodity-level occurrence data. EFSA 2009 Table 1 reports a mean cadmium concentration in potatoes of 0.021 mg/kg across European samples, which is at the lower end of the starchy-roots category mean but still meaningful in population-exposure terms given high consumption volume.

Processing effects

Pending. Peeling removes a modest fraction of total potato cadmium because cadmium is distributed through the tuber rather than concentrated in the surface layer; peel-containing products (potato-skin-heavy dishes, processed products retaining peel) carry somewhat more cadmium than peeled-flesh products. Frying, baking, and boiling do not remove cadmium from the food.

Ingredient-derivative risk

Potato-derived products (potato starch, potato flakes, dehydrated potato) inherit the cadmium concentration of the source potatoes. Potato starch, being isolated from flesh rather than from peel, tends to carry cadmium at the flesh-only concentration and therefore slightly below the whole-potato mean.

Mitigation options

Pending. Cultivar selection, soil management, and peeling are the primary mitigation levers. Note that peeling is in tension with the nutrient-retention rationale that keeps potato skin on in many modern preparations.

Other metals of concern

Some metals not listed in this section because no ingested source yet covers their commodity-level concern; those will populate when the corresponding source pages are ingested.

• Pb: the FDA Closer to Zero 20 ppb Pb action level for single-ingredient root vegetables in processed baby food covers carrots and sweet potatoes specifically (FDA CTZ Pb 2025; see fda-ctz-Pb-rootveg-20ppb); white potatoes are not in the targeted category but the framing is adjacent.
• iAs: not a top staple-iAs contributor (rice dominates, FDA iAs 2020). See arsenic.

Regulatory limits that apply

• codex-cadmium-mls — Codex matrix-level Cd ML for potatoes and starchy roots (pending ingest of CXS 193-1995).
• eu-2023-915-cadmium and eu2023-contaminants-maximum-levels — EU maximum levels for root and tuber vegetables are 0.10 mg/kg (100 ug/kg) for Cd and 0.10 mg/kg (100 ug/kg) for Pb; for potatoes, the maximum levels apply to peeled potatoes after washing and edible-part separation.
• fda-ctz-Pb-rootveg-20ppb — FDA CTZ 20 ppb lead action level for single-ingredient root vegetables in processed baby food covers carrots and sweet potatoes specifically and does not apply to potatoes, but the adjacent framing is worth noting for any future Cd analogue.

FDA TDS FY2018-FY2020 Evidence

FDA’s FY2018-FY2020 Total Diet Study dataset includes this page’s routed matrix as TDS Food 136, “Potato, peeled, boiled.” The normalized row-level data is stored in data/evidence/fda_tds_fy2018_2020_element_results_samples.csv, with per-food/per-analyte summaries in data/evidence/fda_tds_fy2018_2020_summary_by_food_analyte.csv. Concentrations are retained as FDA reported them, with reporting limits preserved separately; reported zeroes are not rewritten as <LOD without a source-specific rule. fda2022-tds-elements-fy2018-fy2020

FDA TDS FY2018-FY2020 Occurrence Values

FDA Total Diet Study FY2018-FY2020 reports prepared/composite-food concentration distributions for this ingredient as TDS food “Potato, peeled, boiled” (fda2022-tds-elements-fy2018-fy2020). Values are in ppb-equivalent on the basis FDA reported. The full sample-level data are stored in data/evidence/fda_tds_fy2018_2020_element_results_samples.csv; per-analyte distributions in data/evidence/fda_tds_fy2018_2020_summary_by_food_analyte.csv. These distributions count as one source under persistent-wiki-ingest-rule synthesis discipline; numerical values stay in body scratch until a second independent source is integrated.

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]*.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.