sentences:  In 2009, the EPA issued an air pollution report that ranked Madison County as the county with the second-highest cancer risk in the country due to air pollution, second only to Los Angeles County, California.According to the U.S. Census Bureau, the county has a total area of , of which is land and (3.4%) is water.Madison County is on the Mississippi River, while the other major body of water is Horseshoe Lake.