With technological strides forward, the Industrial Revolution of the mid-19th century introduced new sources of air. By the middle of the 20th century, the effects of these changes were beginning to be revealed in many countries around the world. In the 1960s, an environmental movement began to emerge that sought to remove the flow of pollutants to the planet’s ecosystems. Out of this movement came events like Earth Day, and legislative victories like 1960’s Clean Air Act. In 1963, in an effort to reduce air pollution, the U.S. Congress passed the Clean Air Act, legislation which has been amended and strengthened in the ensuing decades. However, in 2007 the American Lung Association (ALA) reported that 46% of all Americans resided in counties
