Part two of a three-part series.

Ozone is one of six pollutants for which the Environmental Protection Agency establishes National Ambient Air Quality Standards. Unlike the other pollutants, ground-level ozone is not directly emitted but forms in a reaction between nitrogen oxides and volatile organic compounds — byproducts of thecombustion of fossil fuels.

During the warm weather months, most of the country’s urban regions have elevated ozone levels. In January 2010, EPA proposed a far stricter ozone standard — the third new federal standard in six years — within a range of 70 to 60 parts per billion.

Many scientists and physicians contest EPA’s scientific justification for lowering the standard below the legally binding 85 ppb. Roger McClellan, former chairman of EPA’s own Scientific Advisory Committee, testified that a lower ozone standard is a “policy judgment based on a flawed and inaccurate presentation of the science that should inform a policy decision.”

EPA’s new standard will have more widespread effect across the country than any previous NAAQ.

According to the Congressional Research Service, only 85 of the more than 3,000 counties in the United States exceed the applicable 85 ppb standard. Under EPA’s new standard, the number of federally shackled non-attainment counties could increase to 650.

Texas would go from two non-attainment areas to 10 or more, including Brewster County in the Big Bend area of southwestern Texas — one of the most remote and sparsely populated areas of the country.

Federal “non-attainment” status imposes costly administrative and technical burdens on state and local governments. Designation of a non-attainment area immediately sets a ceiling on economic growth.

When industries plan to expand or open a new plant, they typically avoid location in an ozone non-attainment area.Texas has made dramatic improvements in reducing ozone.

In 2009, all but one of the seven Texas regions with past ozone problems met the legally binding ozone standard.

Even Houston, home of nation’s largest petrochemical industrial complex and notorious for the highest ozone levels in the country, attained the federal standard. Texas devised and implemented an aggressive plan to lower ozone through stringent but targeted controls, cutting-edge science, innovative technology, fine-tuned management and billions invested by the state and private sector.

No sooner did Texas meet the federal limit than EPA radically lowered it.

Now that Texas has reduced key ozone emissions from stationary industrial sources by 80 percent, mobile sources (cars and trucks) now dominate ozone formation. In Houston, mobile sources account for 71 percent of ozone precursors.

Although the Clean Air Act gives states the authority to regulate stationary sources, EPA retains exclusive authority over mobile sources with rarely granted and minimally effective exceptions like California’s “boutique” engine standards.

How can Texas attain far stricter ozone standards when 71 percent of the problem is the exclusive authority of the federal government? Over time, the roughly 250 million vehicles in the current U.S. fleet will be replaced by vehicles that emit at least 88 percent less ozone precursors than older cars.

These improvements in air quality will occur naturally but would be expedited far more by a vigorous economy than by EPA’s dictates. Without a change in federal law, EPA’s attainment deadlines will not accommodate this timetable.

However impossible, a state’s attainment of the ozone standard is mandatory. If a state fails to attain at the prescribed date, EPA can impose multiple economy-choking sanctions.

EPA’s new ozone standard rests on flimsy science of vague statistical correlations. The largest recent study looked at 95 U.S. cities over 14 years. A correlation between ozone levels and adverse health effects was found in only six of the 95 cities. Los Angeles, with by far the worst ozone pollution, wasnot among them.

One Texas study even showed fewer hospital visits for asthma during the summer ozone season than during winter when ozone levels are far below applicable standards.

Science used to justify an ozone standard as stringent as EPA proposes should demonstrate a strong causal connection between ozone levels and health effects. Vague correlations should not support a policy decision triggering federal non-attainment status in more than 600 U.S. counties.

EPA’s new ozone standard will be technologically impossible to meet in most areas. The effect on the nation’s economy will not take long to manifest itself. But the new ozone standard may be lost in the background as EPA moves toward an even more ambitious bid to take over the country’s economic policies.

EPA declared CO2 a pollutant under the Clean Air Act and now mandates CO2 regulation beginning Jan. 2, forcing a climate change policy that Congress failed to enact.

Kathleen Hartnett White is former chairman of the Texas Commission on Environmental Quality and a senior fellow at the Texas Public Policy Foundation.

Mario Loyola directs the Center for Tenth Amendment Studies at the Texas Public Policy Foundation.