Several pollution-producing Southwest Indiana counties would fail to comply with a new ozone standard proposed by the U.S. Environmental Protection Agency (EPA).

The scientific evidence that ground-level ozone is harmful to public health is so overwhelming that even the Bush EPA has proposed a new standard that would improve health protections for millions of Americans if fully implemented and enforced.

Ozone forms when nitrogen oxides and other emissions from power plants, vehicle exhaust and other sources cook together in sunlight, causing a chemical reaction.

Also known as smog, ozone can irritate the respiratory system, reduce lung function and inflame and damage cells that line the lungs. It is particularly harmful to young children, seniors and citizens with lung disease.

Ozone-causing chemicals can travel in excess of 200 miles. The Evansville-area counties in question – which are home to some of the nation’s dirtiest coal-fired power plants – are roughly 100-130 miles upwind from Bloomington.

EPA released the new proposed health standard calling for a national reduction in ozone pollution from the current standard of 80 parts per billion (ppb) to between 70 and 75 ppb.

The agency is taking public comment on the 70-75 ppb range and invited comment from those who thought the standard should be left the same or strengthened even further.

The Clean Air Act requires EPA to investigate and revise the standard every five years. But the agency rarely meets that deadline, and the current standard has been in effect since 1997.

Comments on the new standard can be filed up to 90 days after the proposed standard is published in the Federal Register, which should be some time in early July.

Public hearings on the proposal will take place in Los Angeles and Philadelphia on Aug. 30 and in Chicago and Houston on Sept. 5.

The Clean Air Scientific Advisory Committee for EPA issued a recommendation that the standard be set no higher than 70 ppb to be protective of public health. But intense lobbying by industrial sources of pollution kept the higher level of 75 ppb in the range that EPA will continue to study.

Ozone and other National Ambient Air Quality Standards (NAAQS) are required by Congress to be set at a level that is protective of human health with an adequate “margin of safety.”

That means that people with respiratory problems, such as asthma or emphysema, should not be forced to breathe air that is excessively polluted.

The issue around the margin of safety wording has been and will continue to be controversial because it is usually up to the discretion of the EPA.

However, considerable data has emerged since the last time the standard was set that indicates ozone is a hazard to many people at levels much lower than the current standard, even lower than the range EPA is taking comment on.

If Evansville and environs do not have even a single additional day when levels rise above the current standard, the average of the fourth highest level in each of the last three years is 78 ppb, well in excess of the proposed range of standards.

If the standard is set at 70 ppb, nearly all counties in the region with monitors will be found to exceed the standard and will fall into nonattainment of the new standard. That includes Daviess and Henderson Counties in Kentucky.

That could prove important for permitting of several new facilities in Posey County and in Henderson County, Ky.

A large number of ethanol plants are seeking to locate in this region that would turn corn into ethanol. Those facilities would release relatively small quantities of the pollutants that form ozone, but their cumulative emissions would be substantial and would certainly impede efforts to meet the proposed standard.

That is also true for coal power plants that are proposed for Henderson County and Knox County in Indiana. The impact of those major sources of pollution would make it nearly impossible for the region to meet the improved health standard in the future.

Indiana’s Vanderburgh and Warrick Counties are in nonattainment of the standard for fine particles, or soot. The new standard for ozone will mean they will also be in nonattainment for that pollutant as well.

When issuing standards under the NAAQS, EPA is allowed only to consider health impacts, although their implementation policies for those standards can take into consideration negative economic problems that implementation of the standards would cause.

John Blair can be reched at Ecoserve1@aol.com. He is editor of ValleyWatch.net, where this story originally appeared.