EPA proposes new ozone standards

Jun 21, 2007

The U.S. Environmental Protection Agency announced a proposal Thursday to strengthen the nation's air quality standard for ground-level ozone.

The EPA recommended an ozone standard within a range of 0.070 to 0.075 parts per million, as well as soliciting comments on alternative standards within a range from 0.060 ppm up to the level of the current 8-hour ozone standard, of 0.08 ppm.

EPA scientists said ground-level ozone -- the primary component of smog -- is not emitted directly into the air but is created through a reaction of nitrogen oxides and volatile organic compound emissions in the presence of sunlight. Major man-made sources include emissions from industrial facilities, electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents'

The EPA also proposed revising the "secondary" standard for ozone to improve protection for plants, trees and crops during the growing season. The secondary standard is based on scientific evidence indicating exposure to even low levels of ozone can damage vegetation.

The agency said it will have public hearings on its proposals: Aug. 30 in Los Angeles and Philadelphia and Sept. 5 in Chicago and Houston.

Copyright 2007 by United Press International

Explore further: Food shortages could be most critical world issue by mid-century

add to favorites email to friend print save as pdf

Related Stories

NASA simulation portrays ozone intrusions from aloft

Apr 10, 2014

(Phys.org) —Outdoor enthusiasts in Colorado's Front Range are occasionally rewarded with remarkable visibility brought about by dry, clear air and wind. But it's what people in the mountainous U.S. West ...

US clean-air efforts stay on target, analysis shows

Mar 27, 2014

National efforts in the last decade to clear the air of dangerous particulate matter have been so successful that most urban areas have already attained the next benchmark, according to new research by Rice ...

Recommended for you

More, bigger wildfires burning western US, study shows

8 hours ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

User comments : 0

More news stories

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...