US toughens air quality standards

The US Environmental Protection Agency (EPA) has tightened air quality standards, revising them for the first time in more than a decade.

EPA estimates that the final standards will yield health benefits valued between $2bn and $19bn.

Those benefits include preventing cases of bronchitis, aggravated asthma, hospital and emergency room visits, nonfatal heart attacks and premature death, among others. EPA's Regulatory Impact analysis shows that benefits are likely greater than the cost of implementing the standards. Cost estimates range from $7.6bn to $8.5bn.

The agency said it based the changes on the most recent scientific evidence about the effects of ozone, the primary component of smog.

EPA administrator Stephen Johnson, said: ‘America's air is cleaner today than it was a generation ago. By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward.’

“By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward.

EPA administrator Stephen Johnson

The new primary 8-hour standard is 0.075 parts per million (ppm) and the new secondary standard is set at a form and level identical to the primary standard. The previous primary and secondary standards were identical 8-hour standards, set at 0.08 ppm. Because ozone is measured out to three decimal places, the standard effectively became 0.084 ppm: areas with ozone levels as high as 0.084 ppm were considered as meeting the 0.08 ppm standard, because of rounding.

In announcing the new ozone standard Johnson also announced that he will be sending Congress four principles to guide legislative changes to the Clean Air Act.

He said: ‘The Clean Air Act is not a relic to be displayed in the Smithsonian, but a living document that must be modernized to continue realizing results. So while the standards I signed today may be strict, we have a responsibility to overhaul and enhance the Clean Air Act to ensure it translates from paper promises into cleaner air.’

The four principles recommend that the Clean Air Act and the National Ambient Air Quality Standards (NAAQS) must protect public health, allow for consideration of costs and benefits in making decisions about how to clean the air, provide greater accountability, and be driven by available science.

Johnson stated that these changes are needed to modernize the Clean Air Act.