Russia's Norilsk smelter complex and a town in South Africa's eastern coal mining province have the highest sulfur dioxide (SO2) emissions in the world, according to satellite data from U.S. space agency NASA.

The NASA-compiled data published on Monday was commissioned by environmental group Greenpeace India and used the space authority's satellites to track anthropogenic sulfur dioxide emission hot spots around the world.

Scientists say that excessive exposure to SO2 particles causes long-term respiratory difficulties and stunted growth in infants among other problems.

Norilsk, 300 kilometers inside the Arctic Circle, has the largest individual SO2 emissions, followed by the South African town of Kriel, about 150 kilometers east of Johannesburg, Monday's report found.