Half of U.S. states miss pollution goal

WASHINGTON, Dec. 22 (UPI) -- The U.S. Environmental Protection Agency said Monday 25 states have regions that fail to meet its daily standards for fine particle air pollution.

The EPA said it had notified the 25 governors, along with the leaders of 23 American Indian tribes, that all or parts of 211 counties in their states and tribal lands don't meet the standards, known as PM 2.5.

"These designations are an important step in our steady march toward cleaner air," EPA Administrator Stephen L. Johnson said in a news release. "We will continue working with our state and tribal partners to meet these air quality standards."

The states and tribes that aren't in compliance must take steps to reduce the pollution that forms fine particles, which can cause respiratory and cardiovascular health problems, the agency said.

Two years ago, EPA strengthened the particulate rule from 65 micrograms per cubic meter to 35 micrograms per cubic meter of air to protect public health. The agency said monitored levels of fine particle pollution fell 11 percent from 2000 to 2007 nationwide.