EPA proposes lower ozone level standards

EPA proposes lower ozone level standards
WASHINGTON: The U.S. Environmental Protection Agency has proposed revised standards for ozone level, reducing the current limit by 20 per cent in the coming decades, but the proposal met with criticism, mostly from industry groups.

Releasing the proposal, EPA's administrator Stephen L. Johnson said the current limits on ozone air pollution are inadequate to protect public health and hence the new proposal to revise the existing standars.

He said research has shown that even the allowable levels of ozone can cause disease, but since there are differing opinions, the EPA would accept public comments and feedback on the issue.

Scientists consider low level or tropospheric ozone as a pollutant. It is not created by emission from automobiles or industries, but is formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides. While it was present even before industrial activity started, its concentration has gone up and environmentalists have described it as a greenhouse gas, absorbing some of the infrared energy emitted by the Earth. It is a health hazard and is known to cause asthma and other lung diseases in vulnerable people and to lead to damages to vegetation and diseases in plants and crops. Stratospheric ozone, or the layer of ozone above the surface of Earth, on the contrary, acts as a protective layer.

The EPA's current standard allows up to 84 parts per billion of ozone. It now proposes to lower this to 70 to 75 parts per billion, which is recommended by its own scientists' panel. However, this level is higher than the 60 to 70 parts per billion standard recommended by an independent scientists' panel in October 2006.

According to the EPA, there has been significant progress in reduction of ground-level ozone in the country in the last 25 years -- the levels have come down by 21 per cent -- following its as well as states' and local governments' efforts.

Industry organizations claimed the new standards will mean incurring additional costs. They say EPA is overestimating the harms caused by ozone.

However, health experts welcomed the move. A spokesperson for the American Lung Association said this is an essential move to protect public health. The association, however, said in a statement, "Unfortunately, the tightest new standard proposed by the EPA barely touches the more protective levels recommended by these same independent scientists."

The association had sued EPA to compel it to increase the standard.

The EPA said it will accept feedback from the public for 90 days. It will also hold public hearings before the proposal comes into effect in March 2008.