Chernobyl's effects are still felt

Of course, he added, the situation could vary dramatically from year to year, and there was no likelihood for at least the next 20 years that average rates of contamination would come down.

Absurdly enough, a major factor in the contamination equation is mushrooms - of which reindeer are excessively fond, and which are known to accumulate caesium.

Huge quantities of this element were released by the Chernobyl explosion in the form of radioactive isotopes - a full kilogramme was subsequently calculated to have fallen on Norway.

In a good mushroom year, the reindeer - and other livestock in the most affected areas - gorge themselves, and the isotopes accumulate in their bodies.

Annual ritual

There are several ways around this problem.

One is a treatment, described by the Norwegians as "foddering down", which involves feeding the animals a controlled diet, sometimes laced with a caesium binder - normally ferrocyanides of iron, also known as Prussian blue - for up to six weeks before slaughtering.

Another approach - and a perfect example of Nordic-style lateral thinking - is simply to expand the definition of what is fit for human consumption and what is not.

Norway's permissible radiation level in meat is five times that of the European Union.

Since the Chernobyl disaster in 1986 publication of radiation levels in livestock has been an annual ritual in Norway.

Small wonder that "Rudolph the Red-Nosed Reindeer" is not exactly a regular contender in the Christmas pop charts.