Iraqi Wheat Grain Mercury Poisoning Incident

Within a week beginning on December 21, 1971, patients with similar symptoms appeared in hospitals across Iraq. They had motor dysfunction and symptoms of neurological damage. After investigation by the hospital, it was found that these patients had eaten wheat bread made from a batch of imported wheat seeds.

When seeds need to be transported over long distances, people often use fungicide containing methylmercury. These treated seeds can be sown, but never eaten. As a warning, the seeds were dyed pink, and the bags were painted with black skulls and crosses. The government also ordered distributors to inform farmers that the seeds could not be eaten.

Toxic Wheat Seeds Marked with Warnings and Black Skulls and Crosses

Unfortunately, the warnings on the bags were in English and Spanish, which Iraqi farmers could not understand. The black skull pattern did not serve as a warning there, either. The distributor might not notify the farmers when distributing the seeds. Or they might have notified the farmers, but the farmers did not take it seriously. In addition, the pink dye on the seeds could be washed away, which created the illusion that the toxins had been washed away and could be eaten. But in fact, methylmercury could be washed off.

The farmers had already missed the planting season when they got the seeds, so they were worried that these seeds would reduce the price of the next year's wheat. Therefore, they sold the original grain stock and used these poisonous seeds for winter. In this way, a batch of poisonous seeds became the food for most farmers during winter, which caused a large-scale poisoning tragedy. According to statistics, a total of 6,530 mercury poisoning patients were accepted across Iraq, and 459 of them died in hospitals. The facts were much more severe than this. Due to the imbalance of medical resources, many patients did not have the opportunity to go to hospital for treatment and died at home.

After the incident, the Food and Agriculture Organization of the United Nations and the World Health Organization recommended that seeds treated with toxic substances must be announced in local language, and the hazard signs should also conform to the local culture. Bitter substances can be coated on the surface of the seeds to prevent accidental ingestion. Distributors must also fulfill their obligation to inform. The two organizations also urge countries to abandon the use of methylmercury to kill fungi, and only use methylmercury when having no other better choices.