Outdoor Air Pollution Isn’t Good, But What About the Quality of Indoor Air? 

Outdoor Air Pollution Isn’t Good, But What About the Quality of Indoor Air? 

Air pollution is something that we usually talk about. But when we do that, we usually refer to the outdoor air. It makes sense, because it’s pretty evident. We see smokes coming out of manufacturing facilities, power plants, wildfires and all. 

While those are not great for humans other living creatures in this world, we often overlook the quality of indoor air. If we lived back before the pandemic, we can go outside often and not think about it. 

But right now until we don’t know when, we’ve been spending a lot of our time indoors.  

Pollutants in indoor buildings like our homes or offices are not something that human eyes can see. Dust, pollen, and fumes from everyday items are not that great for us as well. 

There’s a recent report by the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. It highlighted the risk on indoor air quality from chemicals used in everyday items. We’re talking about paint, pesticides, and cleaning products. 

Apparently, air pollution from these things has caused between 340,000 and 900,000 premature deaths, which is 10 times more than previously estimated.  

Coauthor of the study Dr. Benjamin Nault said, “When we think about trying to do things to reduce smog in urban areas, like Los Angeles, we always talk about the car.  

“We can see what’s coming out cars. But when we’re inside, we do not see what is slowly coming off the carpets or the cleaning products we use in our household.” 

According to Dr. Nault, there’s been a lack of research or study on indoor air quality. Probably because everything seems harmless. 

“When we burn toast, we can see the smoke, but we don’t think about everything else associated with the kitchen – cleaning products, what kind of stove top you are using or cooking oil – all these produce fine particles, which we inhale. 

“Covid-19 itself has brought more attention to indoor because we’ve been really pushing the idea of greater circulation and ventilation rates to try to reduce exposure, but that goes hand-in-hand with trying to reduce your exposure of everything else that is inside your house,” Dr. Nault said.  

Indoor pollution to outdoor pollution 

Actually, what we have inside our buildings also have negative impacts towards the outdoors. Another recent study from the same institute found that deodorant, sunscreen, and bug sprays are responsible for a significant amount of the ozone pollution in major urban areas. 

For example, New York City generated about half of the volatile organic compounds (VOCs) produced by people using fragrant personal care products, not vehicle exhaust. And that’s from 2018 field mission. 


apparently sunscreen can also contribute to indoor air pollution that carries itself outdoors


If you don’t know it yet, VOCs are a primary ingredient in the formation of ground-level ozone. These can trigger a lot of health problems in people of all ages, and especially for people with lung disease like asthma. 

And now that we’ve got the pandemic going on, we’re staying home more than ever. That means, more use of whatever we’re using when we’re inside. 

Yet another recent study by Airthings found that indoor CO2 levels in the UK increased by 25% during the lockdown. Well actually, both in Europe and the United States saw a noticeable spike when the lockdowns began the first and the second time. 

More research needed on indoor pollution 

Since it’s become clearer that indoor pollution is also a problem which has been often overlooked, new programs and initiatives are trying to provide answers to this problem. 

For instance, experts at the University of Birmingham are part of a new research program. They’re investigating how air pollutants in homes, schools and workplaces can affect human health in a negative way. 

Professor Francis Pope, chair of atmospheric science at the School of Geography, Earth and Environmental Sciences at the University of Birmingham, said that the lack of data makes quantifying indoor exposure to air pollution more difficult. 

“Also, I think there just isn’t the awareness that indoor environments are important for exposure to air pollution even though we spend approximately 90% of our lives inside,” Professor Pope added. 

One thing that’s feasible for now is installing air quality monitors. It works similarly to smoke alarms and carbon monoxide detectors, detecting and monitoring pollutants inside buildings. 

“Low-cost monitors offer great potential for air quality sensing inside. The sensors are still not perfect for all pollutants, in particular gas phase pollutants are still difficult to measure accurately with these devices.  

“However, particulate matter (PM) air pollution is now easy to measure with cheap devices. Since PM is the air pollutant with the greatest associated health risks, the implementation of these PM devices into our homes would be very useful to change behaviour.  

“When people realise what activities and devices are causing the greatest indoor air pollution they can modify their behaviour accordingly. Stop burning the toast!” Professor Pope remarked. 


Another solution from researchers at MIT 

While more research is needed in terms of indoor air quality and indoor pollutants, some just want to take action. Especially during the times of the pandemic. 

Keeping indoor spaces like classroom safe includes opening windows, adding good heating, ventilation, and air conditioning system (HVAC). But according to researchers from MIT, they can add one more to the list. 

The study shows that specific classroom configurations may affect air quality and necessitate additional measures, to reduce the spread of aerosols. These microscopic particles may carry covid because they can stay suspended in the air for hours. 

Getting rid of aerosols indoors 

Aerosols during the pandemic is a big no-no. For one, the virus that causes Covid-19 is mostly transmissible airborne via aerosols. People exhale these and they can stay floating in the air for long periods of time, especially if the room is not well-ventilated. 

Indoor settings like offices and classrooms usually have limited airflow. As a result, there are higher concentrations of aerosols, including the ones that infected people exhale. 

Now, open windows and HVAC system can help to mitigate this condition. However, in certain situations, additional ventilation methods may be needed to minimize SARS-Cov-2 aerosols. 


classrooms may need to open their windows in the future


According to the study, one ideal scenario involves fresh air entering a room near ground level and moving steadily higher. Then it’s going to exit the room through ceiling vents.  

The researchers came up with this process knowing that hot air rises. People’s body warmth naturally generates heat that carry air toward ceiling vents, at the rate of about 0.15 meters per second. 

Because of the ceiling ventilation, the building can create upward vertical air movement to cycle air out of the room. At the same time, it’s limiting horizontal air movement, which spreads aerosols. 

Challenges to this discovery 

Researchers found that there can be complications. One of which, in their set of simulations focused on closed windows and HVAC use, there were airflow problems in a simulated classroom in winter with cold windows on the side. 

This becomes a problem because cold air near windows naturally sinks. That disrupts the overall flow of classroom air, regardless of people’s natural heat. 

Even so, the researchers said that there are fixes for this problem. Among other things, placing heaters near cold windows limits their impact on indoor room airflow. 

Also, this study has another limitation. First, it examined air quality under specific circumstances. Second, it took place before the coming and yet another outbreak of the more transmissible Delta variant of the Covid-19. 

Coauthor Leon Glicksman said, “It depends to some extent on what the particular conditions are. There is no one simple recipe for better airflow. What this really says is that we would like to see more research done.” 

Well, basically it all comes down to the need for more research. But it’s not all for naught. After all, these findings are something that’ll advance us humans, aren’t they?





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