Economics professors David Keiser, Gabriel E. Lade, and Ivan Rudik summarize a new paper published in Science Advances in The Conversation (US edition) article Ozone pollution in US national parks is nearly the same as in large cities. In it, they discuss ozone trends over time; the impact of bad air days, including driving people away from parks; sources of pollution; and the reduction in ozone over time; and other important topics.
Most startling, as the title indicates, is their finding which contradicts what most of us think about parks as pristine, or at least free from what ails urban and suburban parts of the United States.
. . . we analyzed levels of ozone, the most widely monitored pollutant in parks, and their impact on visits to 33 national parks from 1990 to 2014. The sites we studied included popular parks such as Acadia, the Grand Canyon, Great Smoky Mountains, Joshua Tree, Sequoia and Kings Canyon and Yosemite. We found that while cities once had more "bad air days" with unhealthy ozone levels than national parks, today parks and metro areas have virtually the same number of unhealthy ozone days per year on average. We also found that park visits fall on high ozone days – especially during summer and fall, when peak ozone levels typically occur.
