DENVER (AP) — Monitoring results by Colorado's Air Pollution Control Division show air quality in Denver and the northern Front Range has worsened and the region missed an extended deadline to meet federal health standards.

The Colorado Sun reports the U.S. Environmental Protection Agency is expected to downgrade the Front Range region's ozone to "serious," which means stricter regulations will be imposed.

Mike Silverstein, executive director of the Regional Air Quality Council, the air-quality planning agency for the Denver metro area, says the nine-county region spanning from south of Denver...