It was almost as a footnote to the catalogue of catastrophes Russians have faced over the last week when Sergey Shoigu, Russia's emergency situations minister, announced that there might also be a radioactive addition to the nation's woes.

It's already been the hottest summer in 1,000 years.

Wildfires have killed more than 50 people, wiping entire villages off the map and leaving Moscow blanketed for days under a layer of choking smog.

Since the heat wave began more than 30,000 forest and peat fires have ignited nationwide creating a massive plume of smoke big enough to be seen from space.

Today the winds have changed and the skies over the capital have cleared, a welcome respite for thousands of people doomed to spend sweltering nights in overheated apartments with the windows firmly closed.

Air conditioners now retail at two to three times the market price. Even after getting hold of one it will take several months to get it installed by which time the mercury will have plummeted to the other extreme.

But there may be more reasons to keep windows closed.

Harmful radiation 

Greenpeace and other environmental groups say that fires burning in areas contaminated by the 1986 Chernobyl nuclear disaster could spread harmful radiation. 

Fire crews quickly extinguished blazes in the Bryansk region south west of Moscow, one of the areas worst affected by the Chernobyl fallout. 

Experts say that top soil holds radioactive particles that could be thrown into the air by wildfires.

Officials say that 3,900 hectares of land affected by the Chernobyl fallout have already been engulfed by fire but according to the authorities no radioactive particles have spread. 

Many Russians though are taking the official response with a pinch of salt. 

The country's authorities have whitewashed over catastrophes in the past in a bid to avert panic.

The truth is nobody really knows the full extent of the potential health risks.

For the time being fire crews across southwestern Russia remain extra vigilant lest fires waken remnants of one of the worst disasters of all time.