The EPA's Air Quality Index (AQI) for Topeka reached 143, categorized as "unhealthy for sensitive groups." The high AQI was likely caused by windblown dust from a passing frontal boundary.

Instead, the U.S. air quality index looks at five pollutants regulated under the Clean Air Act: ground-level ozone, ...

As we reconsider nearly $1 trillion of regulatory costs, we will abide by the rule of law to protect consumer choice and the environment,” said EPA Administrator Lee Zeldin in a news release ...

Here's what to know about air quality indexes in Oklahoma. The Air Quality Index is the Environmental Protection Agency's (EPA) tool for communicating about outdoor air quality and how healthy it ...