Coal-fired power plants are responsible for 59% of the sulfur dioxide (SO2) pollution in the U.S., and is directly linked to acid rain. Acid rain changes the pH balance of streams and lakes, ultimately making them unable to support life. Acid rain affects all ecosystems, harms forest heath, plant and animal life, and eats away at man-made monuments and buildings. Long-term acidification continues to threaten the Chesapeake Bay and trout stream habitat. In humans, sulfate particles are ingested in the lungs, causing difficulty breathing, respiratory disease, and death.