Humans are a part of the sulfur cycle in many ways. Human activities have affected the sulfur cycle primarily by releasing large amounts of sulfur dioxide into the atmosphere.
Humans burn sulfur-containing coal and oil to produce electric power. They also refine sulfur-containing petroleum to make gasoline, heating oil, and other useful products. In addition, they convert sulfur-containing metallic mineral ores into free metals such as copper, lead, and zinc.
When humans burn coal, sulfur dioxide is released into the atmosphere. Sulfur dioxide is harmful to almost all parts of the environment. It is toxic to plants, causes irritation in the lungs and nose of humans, and also corrodes metals.
