# Aflatoxin mould (Aspergillus flavus)

**Aspergillus flavus**

**Known today as.** A yellow mould of cereal grains, legumes, and tree nuts, rotting them in the field, in harvest, and in storage.

Kind: Fungus  
Poisoning: Mycotoxins of the moulds (https://thethinkingpress.org/materia-medica/poisons/mycotoxin)  
Deadly: yes

> **Deadly.** Deadly in quantity; a carcinogen in small amounts over time.

## What was it used for?

None.

## What does modern science say?

Aflatoxins are among the most carcinogenic substances known. In Kenya in 2004 contaminated maize killed 125 people.

## Pharmacognosy and toxicology

- **aflatoxin B1**: 
- **aflatoxin M1**: in the milk of animals fed mouldy feed

**Mechanism.** Aflatoxin B1 is metabolised to a reactive exo-epoxide that binds DNA; exposure is linked with a specific mutation in codon 249 of the TP53 tumour-suppressor gene.

**Dose.** Long exposure raises the risk of liver cancer, more than multiplicatively with hepatitis B infection; in the Kenyan outbreak of 2004, 7 per cent of market maize products held over 1,000 parts per billion.

**Standing.** Limits in foods are set in parts per billion: Kenya’s was 20, and the US Food and Drug Administration’s action levels run from 20 to 300.

## What lore surrounds it?

A mould that entered history through a farmyard: “Turkey X disease” killed some 100,000 turkey poults in south-eastern England in 1960, and its cause was traced to peanut meal contaminated by the toxins of *Aspergillus flavus*.

## Sources

- Blount, W. P. (1961). Turkey “X” disease.
- Centers for Disease Control and Prevention (2004). Outbreak of aflatoxin poisoning, Kenya.
- Lewis, L., et al. (2005). Aflatoxin contamination of commercial maize products during an outbreak of acute aflatoxicosis in eastern and central Kenya. *Environmental Health Perspectives* 113: 1763–1767.
- “Aflatoxin.” *Wikipedia* (read 2 October 2026).
- “Mycotoxin” (Turkey X disease). *Wikipedia* (read 2 October 2026).
- “Aspergillus flavus.” *Wikipedia* (read 2 October 2026).
- IARC (2012). *Monographs*, vol. 100F.
- Azziz-Baumgartner, E., et al. (2005). *Environmental Health Perspectives* 113.

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*Aflatoxin mould.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/aflatoxin-mould

Historical description, not medical advice.