# Excerpt — Bruce Ames: from the no-threshold test to "it's all trivial"

*The intellectual heir to Frawley's de minimis, with maximum irony: the man who built the screening tool for
no-threshold genotoxins became the apostle of "synthetic residues are insignificant." All three papers held and
OCR-verified in `papers/lateral/`. Grade **[CONFIRMED-primary]**.*

## Ames, Durston, Yamasaki & Lee (1973), *PNAS* 70(8):2281 — "Carcinogens are Mutagens"
The **Ames test** — the cheap bacterial assay that operationalized the mutagen→carcinogen, *no-threshold*
paradigm (the science that says a genotoxin has no safe dose):

> "Carcinogens are Mutagens: A Simple Test System Combining Liver Homogenates for Activation and Bacteria for
> Detection."

> "[A method for the] detection of carcinogens as mutagens is described."

## Ames, Profet & Gold (1990), *PNAS* 87(19):7777 — "Dietary pesticides (99.99% all natural)"
A decade later, the same author universalizes the trifle — de minimis scaled from one additive to the whole
diet, in a new round number:

> "We calculate that **99.99% (by weight) of the pesticides in the American diet are chemicals that plants
> produce to defend themselves.**"

> Americans eat ~1.5 g/day of natural pesticides — *"10,000 times more than they eat of synthetic pesticide
> residues."*

> "[At] the low doses of most human exposures the **comparative hazards of synthetic pesticide residues are
> insignificant.**"

## Ames & Gold (1990), *PNAS* 87(19):7772 — "Too many rodent carcinogens"
The blade cuts both ways — his attack on the high-dose rodent bioassay (which also undercuts confidence in
clearing synthetics): "about half" of all chemicals tested, natural or synthetic, are rodent carcinogens, an
artifact (he argues) of dosing at the maximum tolerated dose (mitogenesis → mutagenesis).

**Note:** the **HERP table** itself (peanut-butter sandwich and a glass of wine outranking synthetic residues)
is in **Ames, Magaw & Gold, *Science* 236(4799):271–280 (1987)** — **NOW HELD** (operator Taildrop 2026-06-11):
`papers/lateral/ames-magaw-gold1987_science_ranking-carcinogenic-hazards.pdf`, register **H14**,
**[CONFIRMED-primary]**. Verified inside: *"We call this percentage HERP [Human Exposure dose/Rodent Potency
dose]"* (Table 1). (Free full-text mirror: `files.toxplanet.com/cpdb/pdfs/Science-Ranking.pdf`.) Principal
critique: **Perera & Boffetta, *JNCI* 80:1282 (1988)** (HERP conflates exposure-ranking with risk) — wishlisted. The NAS again lent
its name: **NRC (1996), *Carcinogens and Anticarcinogens in the Human Diet*** adopted Ames's "same yardstick"
framing — wishlisted (NAP 5150). See `papers/lateral/_WISHLIST.md`.

**Connective tissue (do not overstate):** Frawley authored in the **inaugural June 1981 *Regulatory Toxicology
and Pharmacology*** — the ISRTP venue where Ames's argument lived. No direct Frawley↔Ames citation was found;
frame as parallel apostles of one logic in one milieu. Ties to `reckoningscience/sections.md` §9/§10.