Norilsk continues to be the largest SO2 emission hotspot. Photo: / Ninara CC BY

Global SO2 air pollution hotspots mapped

The Norilsk smelter complex in Russia continues to be the largest sulphur dioxide emission hotspot in the world.

Power plants and the industrial burning of coal and oil are responsible for two-thirds of the anthropogenic sulphur dioxide (SO2) emission hotspots tracked by satellite data from US space agency NASA, according to a recent study by Greenpeace India. Oil refineries and metals smelters are the other major sources.

Emissions of SO2 contribute to human death and disease from air pollution across the planet. The health impacts come from both direct exposure to SO2 and from exposure to fine particulate matter (PM2.5) that is formed when SO2 reacts with other air pollutants to form tiny sulphate particles. SO2 emissions also contribute to the acidification of soils and freshwater (with damage to ecosystems and biodiversity), and to the corrosion of materials and historic monuments.

In terms of individual hotspots, the Norilsk smelter complex in Russia continues to be the largest SO2 emission hotspot in the world, with annual emissions of nearly two million tons.  Number two on the list is the Kriel area in Mpumalanga province in South Africa. There are 12 coal-fired power stations in Mpumalanga province, making the province the largest SO2 hotspot in the world for emissions from power generation. The third biggest point source is a petrochemical complex in Zagroz in Iran. See Table.

Nornickel is the world’s leading nickel- and palladium-producing company. According to Reuters, the company is implementing a massive programme to improve the ecology of the city of Norilsk and its surroundings. The first stage of the programme has already been completed, and the second phase will involve a US$ 2.5 billion project to help to reduce SO2 emissions in and around Norilsk by 75 per cent by 2023, from 2015 levels.

Looking at individual countries, India is the world’s top emitter of SO2 from large point sources, having recently overtaken Russia and China, which now rank second and third, respectively. These are followed by Mexico, Iran, Saudi Arabia, South Africa, Ukraine, the United States, Turkey and Kazakhstan.

Three European countries appear in the list of the twenty largest SO2 point source emitters in the world: Ukraine, Serbia and Bulgaria. Coal-fired power plants are the main source of high SO2 emissions in all three countries.

It is pointed out that Australia still lacks any legal provisions to limit or reduce SO2 emissions from its power plants, whilst the US, China and EU have had such regulation in place for many years and are continuing to gradually strengthen their emissions standards.

Greenpeace concludes that the ranking of global SO2 emission hotspots demonstrates the need for stronger emission standards for power plants and industry, and a rapid transition away from fossil fuels.

“The burning of fossil fuels such as coal, oil and gas is the largest source of emissions of SO2 resulting in disastrous air pollution and premature deaths. Clean energy could save billions of dollars in health costs and thousands of lives every year. It’s fundamental that governments rapidly transition away from fossil fuels and set stronger emission standards as they shift over to sustainable alternatives,” said Lauri Myllyvirta at Greenpeace Nordic.

The report is accompanied by an online interactive map and a database of the world’s biggest point sources of SO2 pollution, which can both be accessed from the Greenpeace website (link below).

Christer Ågren

Sources: Greenpeace International and Reuters, 19 August 2019.

Table. Top twelve global SO2 emission hotspots in 2018

  Name Country SO2 emissions (kt/yr) Type
1 Norilsk Russia 1898 Smelter
2 Kriel South Africa  714 Coal power plants
3 Zagroz Iran 614 Oil & gas
4 Rabigh Saudi Arabia 515 Oil & gas
5 Singrauli India 507 Coal power plants
6 Cantarell Mexico 461 Oil & gas
7 Matimba South Africa 412 Coal power plant
8 Reforma Mexico 407 Oil & gas
9 Shaiba Saudi Arabia 398 Oil & gas
10 Das Island United Arab Emirates 397 Oil & gas
11 Neyveli India 393 Coal power plant
12 Sarcheshmeh Iran 384 Smelter



In this issue