peat

One local landowner, George Winn-Darley, said the peat fire had produced "an enormous cloud of pollution" that could have been prevented if there had not been live ordnance on site.

"As the peat continues to burn down it is finding the Word War Two ordnance and therefore exploding and we have now experienced over 18 ordnance explosions within key areas," the officer added.

But the wacky challenge, which involves racing through 120 yards of peat bog trench, saw nearly 200 people take part at the annual World Bog Snorkelling Championships at Llanwrtyd Wells, Powys.

The peat here runs to a depth of at least nine metres, which means it has been forming for more than 9,000 years and sequestering carbon for all that time.

"We've got climate change, plant health, issues of peat and as the world gets smaller - who know what diseases," she said.