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Maryland State Government Maryland Department of the Environment

Sulfur Dioxide

Sulfur Dioxide is a gaseous compound of sulfur and oxygen.


Burning of fossil fuels, including fuels used in vehicles, containing sulfur compounds. Sulfur dioxide can be transformed into other products such as fine particulate sulfates and sulfuric acid mist.


The most obvious health effects are irritation and inflammation of body tissues that are contacted by the gas. Sulfur dioxide can increase the severity of existing respiratory diseases such as asthma, bronchitis and emphysema. It also constricts air passages making it difficult to breathe.


On Vegetation : Sulfur dioxide can damage many different types of vegetation. The injury can occur between the veins and on the margins and produces a bleached appearance. Many plants of economic importance are sensitive to sulfur dioxide including potatoes, cucumbers, peas, gladiolus, tulips, grass and several types of trees.

On Visibility : Sulfur dioxide can also reduce levels of visibility. Sulfates are a major component of atmospheric fine particulate material. Because some sulfates have a water absorbing capacity, their impact on visibility is greatly increased at high humidities.

On Rain : Acid rain is suspected to be caused by sulfur dioxide. Acid rain can lower the pH of soils and natural waters, cause mineral leaching, damage vegetation and deplete fish populations in some lakes and streams.

Ozone| Particulate Matter| Sulfur Dioxide
Carbon Monoxide| Nitrogen Dioxide| Lead