Optimize Your Air Quality for Big Impacts on Performance and Health

In this video, Kyle Allred of MedCram interviews Dr. Joseph Allen from the Harvard School of Public Health. He is the director of the Harvard Healthy Buildings Program and an authority on practical ways we can fix the indoor air we breathe to improve our health and improve our own cognitive performance. 

Why should we worry about our indoor air?

Dr. Allen says that the indoor air we breathe matters a lot because we spend nearly all of our time indoors with the statistics showing we spend 87% of our time indoors and 6% of the time in our vehicles. On average, we are breathing indoor air 93% of the time. As a result, the air you breathe while inside your home, office, school, store, etc can make an impact on your health. Indoor sources of air pollution include gasses emitted from gas stoves, scented cleaners, off gassing from floors and paint,  allergens from rodents, pets. Unless you actively remove these, they will tend to build up over time. 

What can you do to improve indoor air quality?

Outdoor sources of air pollution can kill millions every year but the dirty secret about outdoor pollution is that it penetrates inside our homes. Due to the fact that we spend so much time indoors, the majority of our exposure to outdoor air pollution occurs inside. It’s true that the percent of the air pollution outdoors is much higher outside, but due to the fact that we spend such a short time outdoors we actually can get more harmful exposure to the outdoor pollution that has penetrated inside since we spend so much time indoors. Practical things that people can do to improve indoor air quality can include being careful about products that are used in the home that have a low VOC load. If you have a stove it should be vented to the outside, open your windows as much as you can, use green cleaners, take your shoes off in the home, bring in more outdoor air and upgrade your ventilation. 

What is the Harvard Healthy Buildings Program?

The Harvard Healthy Buildings Program puts out a report for 36 tips that can be easily accessed. You want to make sure you have upgraded filters if you have a central system. If you don’t have a central system, then a portable HEPA filter is a good idea.  The main goal is to decrease the particle concentrations that have come into your home. Most of the filters on your air conditioning or furnaces are a low grade filter with a MERV rating of 5-8. For usually only a few dollars more, you can get a higher rating filter such as a MERV 13 (MERV= minimum efficiency reporting value) which is a higher performance filter and will start to capture 80-90% of these particles whereas a MERV 8 could only be capturing 20% of particles. 

It is important to remember to routinely replace your filters especially if there has been a recent fire in your area as heavy smoke can reduce the effectiveness of electrostatic filters by up to 95%.  One thing to note especially with West Coast fires, is that studies have shown that the particles from this can blanket the entire United States.  You have to remember that pollution is not always just a regional phenomena. 

What should you look for in a HEPA filter and CADR rating?

When looking for a HEPA filter you want to look for an air cleaner with a HEPA filter and nothing else. You don’t need sensors etc., and you want to size it correctly for the room you will be using. You want to look at the CADR or clean air delivery rate on the device.  Ideally you want at least a rating of 300 CADR for every 500 sq feet of space. You can go to Harvard Healthy Buildings Program and find an appropriate air cleaner for your room size.  You want to get to about 5 air changes per hour. Typically, a home gets about ½ air exchange per hour on its own. 

Does improving ventilation actually make a difference? 

Studies have found that in schools when there is lower ventilation (worse quality air) children perform worse on reading and math tests,  are absent more often, and even have more asthma attacks.  When the air is too hot children, are more likely to do poorly on standardized tests. We can also apply this to office buildings. Dr. Allen says he just finished doing a study that showed particles (pollution) at someone’s desk  and based on testing, they could see a decline in a person’s cognitive function that was dependent on the air quality. Air quality is linked to cognitive performance. Dr. Allen did an experiment on airline pilots in a flight simulator and changed the air quality without the knowledge of the pilots. They found that the worse the air quality, the more poorly the pilots did on different maneuvers that involved higher levels of thinking. 

The best way to monitor your air is through an air quality sensor that is now more affordable than they were in the past. You can measure carbon dioxide levels that is a great proxy for air ventilation. If there are higher levels of Co2 than 800 ppm, then the ventilation is not that great and you probably need to make some changes even as simple as cracking open a window. 

As technology is advancing and people are becoming more aware of the issues, hopefully greater strides will take place to improve the quality of the air we breathe.  



Healthy Buildings Website | https://forhealth.org 

36 Expert Tips for a Healthier Home Report | https://homes.forhealth.org

 Portable Air Cleaner Sizing Tool | https://forhealth.org/tools/portable-

 Protecting your Health from Wildfire Smoke – Spotlight on Filters | https://www.hsph.harvard.edu/healthyb… 

Professor Joe Allen’s book Healthy Buildings is available where books are sold. Prof. Allen on X (Twitter): https://twitter.com/j_g_allen

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