What to know about air quality alerts 

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Air quality alerts are currently raised higher than usual along the eastern United States due to traveling smoke from Canadian wildfires. Epidemiologist and professor in Mason’s College of Public Health Amira Roess discusses what you need to know about air quality alerts and how it affects your health. 

Why are wildfires in Canada affecting the air in northern Virginia? 

The wildfires that are raging in Northeast Canada approximately 800 miles from those of us in the DMV (D.C.-Maryland-Virginia) are generating tremendous amounts of smoke and pollutants. Satellite imagery shows smoke blanketing our area and many other parts of the United States. 

These fires are the worst that Canada has seen and are being fueled by a lingering high-pressure system over Canada for weeks now that has led to high temperatures and low precipitation. In addition to the high-pressure system, there is another low-pressure system in the northeast. Together these two systems are creating something like a pathway for smoke to move along over parts of the U.S. 

How do I know what the air quality is? 

There are many weather apps that now include air quality. The air quality scale most in use in the U.S. ranges from 0 to 300 and colors are assigned to the different ranges. The colors to look out for are: 

  • Orange (101-150) is considered unhealthy for some populations and individuals who are vulnerable should avoid being outdoors.  

  • Red is considered unhealthy (151-200) for all individuals, and everyone should limit their time outdoors, avoid strenuous activity, and wear a good quality N95 or K95 mask.  

  • Purple (201-300) is considered very unhealthy for all groups and, in addition to the precautions taken under a red alert, everyone should stay indoors when purple alerts are issued.  

  • Maroon (301) is considered hazardous, and we rarely see this.  

Due to the smoke that is being generated by the Canadian wildfires currently, we are seeing red and purple alerts during much of the day. You can learn more about what these alerts mean from the U.S. Air Quality Index. 

 What can you do to protect yourself? 

When air quality is suboptimal (orange), certain individuals should avoid being outdoors. Those with underlying conditions, especially respiratory and heart conditions, the elderly and young children should avoid being outdoors because they are at risk for the worst health impacts from poor air quality. When air quality is poor (red) or very poor (purple), which is what we are seeing right now, then all individuals should avoid being outdoors.  

If you must be outdoors when air quality is poor or very poor, limit your time and you should wear an N95 or a KN95 mask. Remember that we want to make sure we use clean masks. These masks cannot be washed and once they are wet or dirty, they are a lot less effective, so discard them. Wearing scarves or bandanas is not at all effective at protecting you. It's very important to limit your time outdoors.  

If you have pets that need to go out, take them out for short bathroom breaks only. Do not take them on long walks or have them do any strenuous activities. Remember that pets cannot wear masks as this can cause them to panic and can hinder their breathing. Late in the evening air quality tends to improve. 

If you start to develop respiratory or other symptoms due to spending time outdoors, you should contact a health care provider immediately. 

In addition to not going outside, what can you do to stay safe on a red or purple air quality day? 

  1. Limit how much outdoor air comes into your home.  

  1. Keep your doors and windows closed while air quality is poor or very poor.  

  1. When you are home, you can do small things to keep the indoor air quality good, such as not lighting candles and not using gas stoves, if you can avoid it.  

  1. Make sure your HVAC system is working efficiently. This means making sure that you change the filters as the manufacturer recommends and that you stick to your HVAC service schedule.  

  1. If you have neighbors or loved ones that are immune compromised or in the vulnerable groups mentioned above, check up on them and help them avoid being outdoors. You can do small things like taking their garbage out or walking their pets.

Are we going to see more of these situations? 

In general, as we've seen a shift towards higher temperatures in our hemisphere, we are going to see more wildfires and other climate change-related disasters.