Raging forest fires in central Russia, Siberia and western Canada have created an enormous cloud of pollutants covering the northern hemisphere, according to NASA.

Carbon monoxide, one of the most poisonous gases released into the atmosphere from forest fires, has been detected well outside the territories of Russia and Canada.

NASA's Aqua satellite, equipped with an atmospheric infrared sounder (AIRS), has noted a change in the concentrations carbon monoxide at an altitude of 5.5 kilometers (3.4 miles).

Scientists working with the AIRS said earlier that carbon monoxide concentration over European Russia alone, where thousands of hectares of wildfires are raging, increases by some 700,000 tons every day.

Pollutants from Russia and Canada have now formed a ring around the planet and are moving north.

NASA's Aqua and Terra, which is equipped with a thermal emission and reflection radiometer, registered 494 hotspots from fires across Russia on August 11, compared with 582 just a day earlier.

A scorching heat wave has gripped much of European Russia since mid-June, which coupled with the worst drought since the 1970s has made the countryside particularly susceptible to wildfires.

Thousands of emergency workers and military personnel have been working round the clock for almost three weeks to fight the fires in 22 regions, which have so far killed more than 50 people and left over 3,500 homeless. The immediate economic cost of the fires has been estimated at $15 billion.

MOSCOW, August 12 (RIA Novosti)