the us Environmental Protection Agency (epa) has proposed to revise the national
ambient air quality standards for ozone for the first time since 1997. The proposal recommends an ozone standard within a range of 0.07-0.075 ppm
(parts per million). At the same time, it has asked for comments on a range of alternative levels of standards between 0.06 ppm and 0.08 ppm (the
current standards). Although the proposed level is tighter than the existing level, it has drawn criticism from environmental and health groups.
"While the revisions are a step towards cleaner air, epa's plan falls short of the goal recommended by its own experts.
It barely touches the most protective levels recommended by the Clean Air Scientific Advisory Committee (casac)
scientists. They had recommended that standards should be between 0.060 and 0.070 ppm," said Norman Edelman, chief medical officer of the
American Lung Association. Besides, he says the plan leaves the door open to the option of not making any improvements at all.
In October 2006, the casac ozone review panel had said that there is no scientific justification for retaining the current
ozone standards and it needs to be substantially reduced to protect human health. The team had then unanimously recommended a range of
0.060-0.070 ppm for new standards.
But epa says the proposed standards will provide appropriate protection against a variety of health effects associated
with ozone exposure and that standards below 0.07 ppm or above 0.075 ppm will not be appropriate.
"A standard below 0.07 ppm will not be appropriate because evidence linking ozone exposure to specific health effects becomes increasingly
uncertain at lower levels of exposure and above 0.075 ppm, evidence of public health risks exist," says epa.
But environmental groups want further tightening of standards. The final decision is expected to be taken by March 12, 2008.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.