New research has indicated that the health risks from tritium are twice as great as previously thought. The risk if developing cancer is double what had earlier been estimated. The latest investigation was started after fish near a nuclear plant in Cardiff were found to have levels of tritium hundreds of times higher than expected. As a result the National Radiological Protection Board (NRPB) reviewed the risks to human health. They found that tritium-carbon compounds may stay in the body for longer than thought and that the biological effect of tritium in water could be more damaging. This leads to a greater chance that the radiation from tritium could cause cancer.

The NRPB argues that the risk is still within safety limits but other experts have expressed concern. Barrie Lambert, a radiation expert from St Bartholomew's hospital in London expressed concern about the risk to people living near the Cardiff plant who ate a lot of fish.

Chapelcross nuclear power station in Dumfriesshire produces tritium for Trident nuclear weapons and also discharges substantial amounts of tritium into the atmosphere.

This was reported by Rob Edwards in the New Scientist magazine