You may have noticed the reports of air quality alerts in recent days for several large cities including Birmingham, but you may be left wondering what those air quality alerts mean.
A code orange air quality alert - you sometimes hear about it for large cities, but most do not understand what it means. Most recently, air quality alerts have been issued for parts of California, but even cities as close as Birmingham have been affected by these alerts.
There are 6 air quality alert levels, each with a designated color which corresponds to an air quality index - a number from 0 to 500 that describes amounts of pollutants in the air.
Good air quality is color-coded green. Code yellow is moderate air quality. Any index above 100 is considered above the national air quality standard.
Code orange, the current rating for Birmingham, is considered unhealthy for sensitive groups of people, and those with respiratory problems like asthma should limit their time outdoors. A code red alert means means that those with respiratory problems should avoid the outdoors, and everyone else should limit time spent outdoors. Parts of California are currently under a code red air quality alert.
Very unhealthy conditions are represented by code purple, and hazardous conditions are code maroon. In those cases most people should avoid being outside as much as possible.
So what causes these types of air pollution? In Birmingham, it's ground-level o-zone, which is a photochemical smog that can be dangerous to breathe in large amounts. In California, the cause is smoke from wildfires.
Whatever the cause, air pollution can be very unhealthy for all of us. Understand the color-coded system is important so that you know when to take it easy when you go outside.