What are the sources of sulfur dioxide emissions?

Sulfur dioxide mainly comes from stationary pollution sources; about 70% of it results from coal combustion in power plants and other such facilities, around 26% stems from the production processes in non-ferrous metal smelting, steel manufacturing, the chemical industry, oil refining, and sulfuric acid production plants, while other sources account for only about 4%. Small heating boilers and domestic coal stoves are the main sources of low-level sulfur dioxide pollution on the ground.

The combustion of all sulfur-containing fuels produces sulfur dioxide. Sulfur dioxide in the atmosphere primarily comes from stationary pollution sources; about 70% of it results from coal combustion in power plants and other similar facilities, around 26% stems from the production processes in non-ferrous metal smelting, steel manufacturing, the chemical industry, oil refining, and sulfuric acid production plants, while other sources account for only about 4%. Small heating boilers and domestic coal stoves are the main sources of low-level sulfur dioxide pollution on the ground.

Sulfur dioxide is primarily generated by the combustion of sulfur-containing substances such as coal and fuel oil; it also comes from natural sources such as volcanic eruptions and forest fires. Sulfur dioxide has a strong irritating effect on the conjunctiva and mucous membranes of the upper respiratory tract, and it can damage the respiratory organs, leading to bronchitis, pneumonia, and even pulmonary edema and respiratory paralysis. In the short term, exposure to a sulfur dioxide concentration of 0.5 milligrams per cubic meter of air increases the mortality rate among the elderly or those with chronic diseases; concentrations above 0.25 milligrams per cubic meter can worsen the condition of people suffering from respiratory diseases. Prolonged exposure to a concentration of 0.1 milligrams per cubic meter of air leads to an increase in respiratory problems in affected individuals. Additionally, sulfur dioxide can cause corrosion, peeling, and discoloration in metal materials, building structures, cotton and synthetic fiber fabrics, leather, and paper, thereby damaging these materials. It can also cause plant leaves to turn yellow or even die. Environmental quality standards specify that the average daily concentration in residential areas should be below 0.15 milligrams per cubic meter, and the average annual concentration should be below 0.06 milligrams per cubic meter.