RENEE MONTAGNE, host:
It's been 10 years since the government set the standard for ground-level ozone, better known as smog. Now the Environmental Protection Agency says it wants stricter air pollution standards.
Mr. STEPHEN JOHNSON (Environmental Protection Agency): Based upon the current science, I have concluded that the current standard is insufficient to protect public health.
MONTAGNE: That's EPA administrator Stephen Johnson, speaking in a teleconference this morning.
NPR's Elizabeth Shogren is following this story and joins us now. Good morning.
ELIZABETH SHOGREN: Good morning, Renee.
MONTAGNE: How much does the EPA want to tighten the standard, and why now?
SHOGREN: The EPA wants to tighten the standard from 80 parts per billion to 70 or 75 parts per billion. What that means is that they change the level, making it tighter, because what they say is that science in recent years has shown that ground-level ozone or smog is much more harmful to people's health than anybody knew before.
It not only exacerbates asthma and other lung problems, sending people to the hospital, but it also causes premature death.
MONTAGNE: Is this new standard then likely to be accepted or will there be some sort of strong opposition?
SHOGREN: Well, the interesting thing here is that EPA under the Clean Air Act has the power to set this standard without considering the economic impact. Now, that doesn't mean there won't be opposition. Business groups have already signaled that they oppose this standard and that's because setting a tougher standard means that across the country there will have to be big changes.
New pollution control devices will have to go on power plants and factories and people might have to start getting more testing of their vehicles to make sure that they meet pollution standards in places where they've never had to do these things before. And so people will oppose it.
And last time, 10 years ago, the industry groups opposed it so strongly that they took it all the way to the Supreme Court, but the Supreme Court did support the EPA's right to go ahead.
MONTAGNE: And what do environmentalists have to say about the EPA's proposal?
SHOGREN: Well, the environmentalists are a little bit cautious about what the EPA has done. Because the EPA has said that they favor making the standards stricter, but they've also said they'll take comments on keeping it the same. And environmentalists are a little worried that in the end EPA will wimp out. And so they are watching this very cautiously.
MONTAGNE: So they like the idea but they're afraid it just won't happen?
SHOGREN: Well, they think the standards need to be strict. They think that the standard - that EPA might set a standard that's not quite strict enough. And that's because the research has shown that with ground-level ozone, there's no level where deaths stop occurring because of it. So even if you reduce levels lower, people will still be dying because they're breathing this stuff. And so it's a very difficult standard to set. There's not a safe zone where you can say, as long as you lower it below this level, no one will die.
MONTAGNE: What parts of the country would be considered to have unhealthy air if the proposal is finalized?
SHOGREN: Well, that's interesting because now you've got a scattering of places on the East Coast that have unhealthy air, and a few in the Midwest and Texas, and also most of Southern California. But in the future, what you'd have is much of the Eastern half of the country would be considered to have unhealthy air, at least part of the year, unless they clean up. And under these rules, various parts of the country would have to clean up at various different times - the deadlines stretch between 2013 and 2030.
MONTAGNE: Elizabeth, thanks very much. NPR's Elizabeth Shogren.