The Environmental Protection Agency on Thursday set a tougher standard for the air you breathe -- saying exactly how many particles of soot are safe.
But scientists and health experts say the new standard isn't tough enough.
The EPA decided to reduce the amount of fine particles, or soot, that it considers is safe to be in the air on any particular day. But the agency decided not to tighten the annual standard for fine particles.
"Today EPA's is issuing the most health protective national air quality standards in our nation's history," EPA Administrator Steven Johnson said.
But many health experts said the agency should have made both the daily and the annual standards tighter. In fact, EPA's own science advisory board urged the agency to do this.
"Compared to what the EPA's science advisory board asked them to do the standard that they're setting is going to result in more deaths in each year than died in Sept. 11 from the terrorists attacks," said Joel Schwartz, an environmental epidemiologist at Harvard University.
Schwartz said scientists, medical experts and environmental groups all made the risks clear to the EPA.
But EPA Administrator Johnson said the science is not that clear.
"The point I was making is that this is very complex science and that reasonable people can disagree," Johnson said.
Johnson said the new standard is strict enough to protect people's health.
Fine particles come from the exhausts of power plants, cars and factories. They get into people lungs and trigger asthma attacks and lung failure. Soot also can cause heart attacks or make them more deadly. The EPA said fine particles are responsible for thousands of deaths per year.
Environmental and Public Health groups criticized the EPA for failing to protect people. "The air quality standards tell the public when the air is safe to breathe they're supposed to be based on the best most accurate science available. It's very clear in this case the EPA is not following the science but setting standards that are higher than a level recommended by EPA's staff scientists and outside scientific advisors," said Paul Billings represents the American Lung Association.
Industry groups don't like the new EPA standards either. they say they're too strict.
"We think the EPA has jumped the gun by adopting a more stringent fine particle standard before the existing standards have been given a chance to work," Dan Riedinger of the Edison Electric Institute represents the power industry.
The new standards go into effect immediately. Over the next several years, states will be required to cut pollution to meet the new standards.