ATSDR 2008 — Toxicological Profile for Aluminum

The September 2008 ATSDR Toxicological Profile for Aluminum is the comprehensive United States toxicology synthesis for elemental aluminum and aluminum compounds, prepared under CERCLA Section 104(i) authority and the September 2008 edition supersedes the September 2006 draft for public comment. The profile derives Minimal Risk Levels for oral exposure at intermediate (15-364 days) and chronic (≥1 year) durations, declines to derive an acute-duration oral MRL on inadequate-data grounds, and characterizes aluminum exposure from food, drinking water, ambient air, aluminum-containing medications, and consumer products. As of the access date below, ATSDR has not published a finalized post-2008 update.

Key numbers

Minimal Risk Levels (oral exposure)

The modifying factor of 0.3 accounts for the higher bioavailability of aluminum lactate (the test article in the principal studies) relative to aluminum compounds typically present in drinking water and the U.S. diet. Per the derivation footnote at p. 24-26 of the profile, the chronic MRL arithmetic is 100 / (300 × ⅓) ≈ 1 mg Al/kg/day; the intermediate MRL arithmetic is 26 / (100 × ⅓) ≈ 1 mg Al/kg/day. Both MRLs are anchored on neurological and neurodevelopmental endpoints (Section 2.3, pp. 15-26).

Gastrointestinal bioavailability

Dietary intake (United States, FDA Total Diet Study; Pennington and Schoen 1995)

The profile notes that 2-year-old children consume approximately three times more aluminum per kilogram of body weight than adult men or women (0.48 vs 0.18 and 0.15 mg Al/kg/day, recalculated by Greger 1992). International comparators reported in the profile: U.K. average adult intake 3.4 mg/day (MAFF 1997); France average intake 4.2 mg/day (Biego et al. 1998).

Aluminum in infant feeding (Section 6.6)

Pennington and Schoen 1995 separately estimated that soy-based formula contributed 0.161 mg Al/day to 6-11-month infants, equivalent to 23.0% of their total dietary aluminum intake — the largest single contributor in that age group.

Aluminum from antacids, buffered aspirin, and other medications

When large oral aluminum loads (1,000 to 4,000 mg/day) are ingested as antacids, less than 1% is absorbed in healthy individuals (Gorsky et al. 1979; Kaehny et al. 1977; Reiber et al. 1995).

Major dietary sources of aluminum (FDA Total Diet Study; Pennington and Schoen 1995)

For 6-11-month infants, the top five contributors total 62.6% of dietary aluminum: soy-based formula (0.161 mg/day, 23.0%), processed American cheese (0.122 mg/day, 17.4%), yellow cake with icing (0.088, 12.6%), strained green beans (0.038, 5.4%), and pancakes (0.029, 4.1%). For 14-16-year-old males (the highest-intake group at 11.5 mg/day), cornbread is the dominant contributor at 4.209 mg/day (36.6% of total intake), followed by processed American cheese (1.978, 17.2%), pancakes (1.038, 9.0%), yellow cake with icing (0.925, 8.0%), and taco/tostada (0.398, 3.5%). Across age groups the consistent leaders are aluminum-additive-containing baked goods (cornbread, pancakes, muffins, tortillas, baked goods with leavening agents) and processed cheese.

Ambient air

Background atmospheric concentrations in the United States range from 0.005 to 0.18 µg Al/m³ (Hoffman et al. 1969; Sorenson et al. 1974). At a 20 m³/day inhalation rate the upper-end background concentration delivers 3.6 µg Al/day, an order of magnitude smaller than dietary contribution. Urban and industrial air ranges from 0.4 to 8.0 µg/m³, delivering 8 to 160 µg/day — still small relative to diet.

Drinking water

Median concentrations in U.S. systems: 0.043 mg/L without coagulation treatment, 0.112 mg/L with coagulation treatment (Miller et al. 1984a). At a 1.4 L/day adult consumption rate, drinking water contributes approximately 0.06 to 0.16 mg Al/day, roughly 1% of the 7-9 mg/day adult dietary total. Public Health Statement notes that “several cities have reported concentrations as high as 0.4-1 mg/L.”

Methods

The profile is a literature synthesis prepared in accordance with the ATSDR-EPA guidelines published in the Federal Register on April 17, 1987. Studies were identified through the agency’s standard search of TOXLINE, MEDLINE, EMBASE, CA Search, and other indexed bibliographic databases; CERCLA-mandated peer review was conducted by an external panel of three subject-matter experts (Jerrold Abraham, Upstate Medical University; Michael Aschner, Vanderbilt University Medical Center; Robert Yokel, University of Kentucky College of Pharmacy). MRL derivations follow the ATSDR Minimal Risk Levels framework documented in Appendix A; NOAEL/LOAEL identification used study-by-study expert review rather than benchmark dose modeling because the available data either had incomplete dose-response reporting or did not produce adequate BMD fits.

Provenance notes

The PDF was first retrieved via WebFetch on 2026-04-25 from the canonical ATSDR URL (atsdr.cdc.gov/toxprofiles/tp22.pdf). The manual-fetch copy in the June 3 Folder is the same document (SHA-256 f959d098...833b42, 357 pages, 8.6 MB) and is the basis for the 2026-06-04 merge-enhance pass. License us-government-work; no copyright restriction applies. The ATSDR website is the official publication channel for Toxicological Profiles, so the agency URL is the primary-source citation for all values recorded above.

The 2008 profile remains the operative ATSDR aluminum reference as of the access date; ATSDR has not finalized a post-2008 update.

Verification notes

This page was merge-enhanced on 2026-06-04 from a 2026-04-25 pre-current-schema revision. The prior revision contained two errors corrected on this pass:

• Chronic oral MRL derivation arithmetic. The prior revision stated “composite uncertainty factor 100” and “100 ÷ 100 = 1 mg Al/kg/day.” Per Section 2.3 (page 26 of the profile), the chronic-duration oral MRL was derived by dividing the Golub et al. 2000 LOAEL of 100 mg Al/kg/day by an uncertainty factor of 300 (3 minimal LOAEL × 10 animal-to-human × 10 human variability) and applying a modifying factor of 0.3 for the higher bioavailability of aluminum lactate relative to typical dietary and drinking-water aluminum compounds. The corrected derivation and the parallel intermediate-duration derivation from Golub and Germann 2001 (NOAEL 26 mg Al/kg/day; UF 100; MF 0.3) are now in the MRL table.
• Conflation of the two oral MRLs. The prior revision attributed both the intermediate and chronic MRLs to Golub et al. 2000. Per Section 2.3, only the chronic MRL is anchored on Golub et al. 2000; the intermediate MRL is anchored on Golub and Germann 2001.

The prior revision also omitted the soy-based and milk-based infant formula concentration data (Section 6.6, page 225) and the dietary intake by age-sex group (Table 6-5, page 216) that bear directly on certifiable infant-and-child food categories. Both are now included in Key numbers.

The prior revision’s Implications block contained a wiki/HMTc firewall violation: “HMT&C calibration to the EFSA TWI is the more conservative posture” is a synthesis claim about HMTc policy that does not belong on a source page (CLAUDE.md Part 2). The block has been removed; the literature comparison between ATSDR’s MRL and EFSA’s TWI is a legitimate observation, but the framing as guidance to HMTc belongs in a synthesis page or HMTc certification document, not here.

Audit subagent (2026-06-04) flagged two Check 2 concerns: (1) ingredients/soy-based-infant-formula and ingredients/milk-based-infant-formula not in docs/gpt-collaboration/taxonomy-snapshot.md, and (2) antacid-medication not in the documented matrices vocabulary. Verified against the live wiki: wiki/ingredients/soy-based-infant-formula.md and wiki/ingredients/milk-based-infant-formula.md both exist (the taxonomy snapshot is generated 2026-05-18 and is stale; the ingredient pages predate it). False positive — slugs retained. The matrices concern was real: antacid-medication is not in the documented matrices list in docs/gpt-collaboration/system-prompt.md and antacids are pharmaceuticals rather than a food matrix. Removed antacid-medication from the matrices array; the source’s antacid exposure data remains in Key numbers narrative form.

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.