epa has estimated illustrated annual costs at $3.9 billion for a standard of 70 ppb. the estimated benefits billion. the estimated benefits outweigh the estimated cost as much as a ratio of three to 1. meeting a standard of 6565 parts per billion is projected to provide additional benefit. implementing has always been and will continue to be a federal, state, and travel partnership. local communities, states, tribes have already shown we can reduce ground-level ozone while our economy continues to thrive. nationally average ozone levels have fallen by one third and 90% of the areas originally identified as not meeting the ozone standard set and 97 now meet the standards. we have reduced air pollution and our economy has grown. we expect his progress to continue. resisting proposed federal standards is leading to substantial reductions and ozone nationwide which we will help improve air quality and helped many areas meet any revised standard. exposure to ground-level ozone, a key component of smog can have serious consequences for health and the environment. we are loo

to give full consideration to setting a 60 ppb standard and to finalize a standard that will protect public health. there is broad consensus in the scientific and medical communities that ambient ozone is harmful to human health. in 2011, or team-leading medical and public health organizations including the american academy of pediatrics, the american heart association, the wreck and lung association, and the american thoracic society cosigned a letter to the obama , "thestration saying ozone health standard must protect those who are most vulnerable from the dangerous health impacts of ozone, ." have alsot scientists concluded there is a causal relationship between short-term ozone exposure and respiratory health effects. this conclusion is based on the findings from more than a thousand studies carried out over decades and demonstrating ozone exposure leads to increased hospitalizations and deaths, reduced lung function, and increased airway reactivity. as one example of many, a 2010 study by scientists at emory and the georgia institute of technology found that in the atlanta metr