Clean air group says Denver, Fort Collins improving on ozone

DENVER (AP) — Ozone pollution has improved in Denver and Fort Collins, but both cities remain among the 15 worst in the nation, the American Lung Association said.

Denver had the 11th-worst ozone levels and Fort Collins had the 15th-worst, the association said in its 2017 clean air report released late Tuesday.

Last year, Denver was eighth and Fort Collins 10th.

Ozone can be harmful to people with...