Question

If the AQI is 459, what does it indicate about the quality of the air?

Answer 1

An AQI of 459 falls well into the highest U.S. category “Hazardous” (the maroon range of 301–500) and represents a health warning of emergency conditions in which the entire population is likely to be affected; as the index approaches the top of the scale, risks to health become more severe. People should avoid all outdoor exertion, remain indoors with windows and doors closed, use air filtration if available, and seek medical attention if they experience symptoms such as difficulty breathing, chest pain, or severe coughing; local authorities may issue additional emergency guidance during such events.