That's a dramatic air quality improvement that we can build on by allowing states to continue implementing the existing standards. There is no compelling health or scientific evidence to support issuing new standards before fully implementing the current ones, but EPA has done so anyway. Further tightening the standards to the proposed range of 65 to 70 ppb could be enormously costly to the economy. Due to naturally occurring background levels of ozone, even pristine areas of the country with no industrial activity, such as national parks, could be deemed out of attainment under new standards. Virtually any human activity that causes emissions could be restricted in the name of meeting unachievable standards, putting millions of jobs at risk.