Poor air quality triggered orange, red and purple alerts over a large chunk of the U.S. on Thursday, as seen in this map published by the federal air quality site AirNow at 7 a.m. ET. AirNow.gov ...

Green (0–50) and yellow (51–100) indicate safe conditions, but orange, red, purple, and maroon signal escalating dangers, with maroon as an emergency state.

The smoke has made the air in Transylvania and Henderson counties very unhealthy. Both areas are under a Code Purple advisory on Friday, March 28.

On a Code Red Air Quality Action Day, young children, the elderly, and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air ...

Green (0–50) and yellow (51–100) indicate safe conditions, but orange, red, purple, and maroon signal escalating dangers, with maroon as an emergency state.