Thallium Poisoning
Thallium is rare today, but it’s a classic poison: odourless, tasteless and slow to show. The combination of very painful nerves followed by hair loss is the clue.
Symptoms
- First days: tummy pain, vomiting or diarrhoea, or constipation.
- Within a week or two: severe burning pain and numbness in the feet and legs, weakness and confusion.
- After 2–3 weeks: hair loss, often dramatic, and pale lines across the nails.
- Severe poisoning can affect the heart, breathing and brain, and can be fatal.
Who’s at risk today
- Deliberate poisoning (still reported worldwide)
- Some imported products or contaminated herbal or traditional medicines
- Rare workplace exposure in electronics, optical glass or chemical manufacturing
Diagnosis and treatment
- A urine thallium test confirms it. Doctors need to think of it, because routine blood tests look normal.
- Treatment is Prussian blue, a dye taken by mouth that traps thallium in the gut so it’s passed out. Severe cases may need dialysis.
- Recovery of nerves can take months and may be incomplete.
Call 000 for severe illness. For advice on a possible poisoning, call the Poisons Information Centre on 13 11 26.
Weird history
- In early-1950s Sydney, thallium rat poison was easy to buy during a rat plague. Several notorious poisonings followed, including Caroline Grills, who killed four relatives with thallium-laced treats, and an attempted poisoning of rugby league player Bobby Lulham, who survived.
- Thallium went back on the NSW poisons list in 1954.
- Agatha Christie’s novel The Pale Horse described thallium poisoning so accurately that a reader is said to have recognised a real case from it.
Common questions
What are the symptoms of thallium poisoning?
Tummy symptoms in the first days, then severe burning pain and numbness in the legs, followed 2–3 weeks later by hair loss. Severe poisoning can be fatal.
How is thallium poisoning treated?
With Prussian blue, taken by mouth, which binds thallium in the gut so it’s passed out. Severe cases may need dialysis.
Is thallium still used as rat poison?
Not in Australia. It was restricted again in 1954 after a series of poisonings in Sydney, and it is banned for this use in many countries.
Helpful resources
- Poisons Information Centre: 13 11 2624/7 advice on poisoning anywhere in Australia. Free.
Evidence and more information
maladywise.com/thallium/