Welcome to another coronavirus post. Now, I know I said I wouldn’t dwell on the topic and go back to business-as-usual science based posts, but to be honest, covering other topics interests me less than it would otherwise, considering COVID-19 is impacting our daily lives in significant ways. And of course, my public health brain can’t help but find fascination in reading the emerging science about it as it comes out. Today, I thought I’d focus on coronavirus and air quality. Like with my post on coronavirus and food safety, I’m going to focus on synthesizing what we know so far; considering COVID-19 is a novel disease, we are still learning about it and trying to understand it fully.
This post will cover two topics: first, we’ll discuss what we know so far about coronavirus and air quality, and how and why the disease may be impacting air quality. Second, given that many of us are spending most of our time indoors, we’ll chat about indoor air quality in general, and what you can do to improve the air quality in your living space.
If you’d like to learn more about COVID-19, please visit the WHO website, or feel free to visit any of my posts about it thus far below:
- Food safety and coronavirus: What do we know so far?
- Some public health definitions to help you understand recent news and COVID-19
- Supplements for Immune Support: What does the science say?
- Are frozen and canned fruits and vegetables nutritious?
I plan to revisit this post once a bit more pollutant raw data is available, and am considering even running a mini analysis on my own. I am also working on a post about what increases risk of and transmission of zoonotic diseases. Stay tuned!
Are lockdowns and quarantines due to COVID-19 decreasing levels of air pollution?
News reports from around the world seem to indicate that yes, the slowdown in manufacturing and drastic decrease in transportation are decreasing levels of some pollutants.
Considering combustion emissions from vehicles are a major source of many pollutants including PM2.5 (read more about what PM 2.5 is here) and CO2, it is feasible that emission of some pollutants has decreased, given that travel has decreased and far fewer people are commuting to work or social events.
Additionally, when you consider the abrupt halt in many industrial manufacturing processes that has also occurred over the past few months, a decrease in levels of some pollutants seems feasible, as well.
However, while many media outlets have reported these decreases in air pollution across parts of Europe and in some cities in the US based on satellite data, peer-reviewed literature on the topic has been sparse.
Now, this does not mean these reports are untrue; in fact, it’s likely that they are. I just wish there was a bit more peer-reviewed literature published on the topic so I could feel more confident in synthesizing an interpretation on the matter.
I was able to find one assessment of pollution levels in China pre and post-lockdown, which found that carbon emissions dropped 25% as a result of the swift halt in industrialized activities. And a NASA report found NO2 (another pollutant) dropped 30% between January 1 – February 24, 2020.
But the NASA scientists note that this drop in pollution doesn’t necessarily mean the air quality is ‘good’ or healthy across China. Air pollution is still a major issue, even if we see what is inevitably a temporary decrease in emission levels.
A scientist at Columbia has also stated that pollution levels at her monitoring station in the city have dropped in recent weeks compared to pre-shelter-in-place levels.
Like the media reports mentioned above, these results aren’t peer-reviewed or published in any journal. In fact, I couldn’t find any peer-reviewed journal articles about air pollution levels in Europe or the United States pre and post COVID-19.
Upon some reflection, this is likely because it is a bit early to take a measurement that would span a long enough time period to be meaningful to show us what, if any, potential decreases in emissions are occuring, and if they are lasting.
Most air pollution and climate experts warn, however, that even if there is a decrease in emissions now, it is likely temporary, and not necessarily worthy of celebrations. Even if we did decrease carbon emissions by, say, 30%, the emissions levels would still be higher than they were a decade ago.
Additionally, the Trump administration issued a memorandum on March 26, 2020 that informed companies that the EPA would not be subject to fines or other legal enforcements for failing to monitor and report their levels of air, water, and soil pollution, citing the COVID-19 outbreak as the reason for the relaxation of pollution regulation enforcement.
The document states that companies are expected to comply where ‘reasonably practicable,’ and return to compliance as soon as they can.
Why is strict regulation of pollution important? Well, it costs some industries time and money to minimize, monitor, and report their levels of pollution. It can be very tempting for some to skip these steps.
Many environmental public health professionals (myself included) worry that the relaxation in enforcement will encourage some industries to pollute without fear of any repercussions.
So, even if emissions are reduced due to the drop in citizen commuting habits, travel, and the decrease in industrial manufacturing, it seems as if industry (in the US, at least) may have more wiggle room to increase the amount of pollution they produce.
I am eager to see how the next few months play out in the US. I think I may take my own whack at some data analysis with EPA monitors in the US after a few more weeks have passed to see how levels of emissions are fluctuating throughout this year and compared to last. Stay tuned!
How does air pollution impact people with COVID-19?
It’s worth noting that air pollution causes an estimated 7-8 million preventable deaths per year, and that people who live in areas with poor air quality are more likely to have respiratory illnesses including asthma and COPD, cardiovascular disease, cancer, and neurological distress. There is also some weak evidence to suggest it may be associated with type 2 diabetes.
Why is this concerning? Well, several conditions caused by or associated with air pollution, including asthma, COPD, cardiovascular disease and diabetes are conditions that are considered ‘high risk’ for developing complications with COVID-19.
Thus, areas that have high levels of air pollution may have more people who are vulnerable to becoming seriously ill if they contract COVID-19. Sadly, high levels or air pollution are often found in lower income areas.
Compounded with poverty, which is itself a risk factor for poor health, it seems like mixing air pollution with coronavirus in areas that suffer from high levels of pollution could cause already vulnerable populations to becoming even more vulnerable to this disease.
*If you want to read more about what air pollution is and how it causes chronic illness and death, check out this post. And, if you want to read about what it means when your phone says, ‘Unhealthy Air Quality for Sensitive Groups,’ check out this post.
What about indoor air quality? Now that I’m inside all the time, should I be thinking about indoor air quality?
So happy you asked! Indoor air quality is the air within and around buildings. I mentioned earlier that air pollution is responsible for an estimated 7-8 million deaths per year; 3.8 million of those deaths are a result of indoor air pollution.
Indoor air quality is actually super important to human health. People in the US spend about 90% of their time indoors (during non-pandemic times), and the concentration of some pollutants is 2-5 times higher inside compared to outside.
Indoor air quality is affected by many things, including microbial contaminant like including bacteria and mold, incomplete combustion of stove top cooking fuels (such as dung, wood, and coal), insecticides used for pest control, secondhand smoke, VOCs (read all about VOCs in this post), and other gases including carbon monoxide and radon.
Lots of furnishings, cleaning supplies, and building materials that you bring into your home can also impact your air quality. Unfortunately, harmful compounds including VOCs, ozone, formaldehyde, flame retardants, and plasticizers are commonplace in commercially purchased furniture and cleaning products.
How does indoor air quality impact human health?
Indoor air quality can have a significant impact on human health. Exposure to indoor air pollutants can result in a condition known as sick building syndrome, or SBS. People with SBS experience headaches, respiratory distress, and fatigue, among other ailments.
In addition to causing irritation of eyes, nose, and throat, indoor air pollutants can cause respiratory distress and diseases, cardiovascular disease, cancer, headaches, dizziness, and fatigue.
Other indoor air pollutants, like dander and other allergens, may increase risks of asthmatic attacks.
If we’re all staying inside, how can we improve our indoor air quality?
Well, one of the most effective ways is via source control, meaning that if you know what is emitting the pollution and have the power to stop it or slow it, you should. This can mean sealing off asbestos or adjusting gas stoves to be more efficient.
Furthermore, you can reduce some of the pollutants in your air by making a conscious effort not to bring heavy emitting products into your home. For example, many pieces of furniture, carpets, paints, building and crafting materials, and mattresses emit large amounts of VOCs, flame retardants, formaldehyde, and other pollutants.
If you must purchase new furniture or are embarking on a project, strive to select low or no VOC or flame-retardant free options. Admittedly, this takes a bit of work, as heavy-emitting furniture and building materials are the norm, but alternatives do exist. Unfortunately, they often come with a higher price take, or may not be available or practical for you to purchase or use.
If you must bring pollutant-emitting materials into your home, be sure to follow the instructions for both use, storage and disposal, and importantly, ventilate your living space.
Improving ventilation can help lower the concentrations of many indoor air pollutants in your living space. If you are working with a polluting chemical or furnishing, it’s imperative to ventilate properly.
But even if you’re not, proper ventilation may improve your indoor air quality. If there is good outdoor air quality where you live (which, if you’re in the US, you can check by entering your zip code when prompted at the site found through this link), opening the windows can provide ventilation that may improve the air quality of your living space.
As a bonus, ventilation and proper air circulation may be helpful for reducing viral load in common places, like grocery stores, so if you are managing a public space and have the power to control ventilation, keep in mind opening windows and doors might reduce viral spread.
Some newer HVAC systems can also aid with ventilation. Each building and system varies, so check yours, as most residential forced temperature and air control systems do not bring outdoor air inside.
And it’s worth noting that under certain temperature and moisture conditions, improperly maintained HVAC systems may be a breeding ground for bacteria with certain Be sure to keep your HVAC cleaned and maintained properly: see this resource for more information on how and when to do so.
To decrease the allergen load in your living space, consider regularly cleaning their homes, which include furniture, carpets, and bedding. Washing your sheets, carpets, and furniture can remove some of the allergen load and improve air quality.
Use dehumidifiers to avoid mold build up. And, if you have cockroaches, which can cause pretty intense respiratory distress in those who are allergic to them, aim to get them under control (preferably without the use of chemicals or insecticides).
Avoid wood-burning stoves, fireplaces, kerosene heaters, and candles, which can all emit pollutants into your living space. And if you smoke inside, consider stopping for the health of everyone in your home (pets included).
Certain plants have been thought to improve indoor air quality. While plants have not been shown to significantly decrease PM, several, including Hemigraphis alternata (aka ‘purple waffle plant’) Hedera helix (aka ivy), Hoya carnosa (aka ‘porcelainflower or wax plant,’), and Asparagus densiflorus (an evergreen perennial plant) have been found to be some of the most effective plants to remove VOCs.
However, some scientists have expressed concern that any reasonable amount of houseplants wouldn’t significantly improve indoor air quality, and that certain plants may even contribute to the amount of allergens in the air.
Lastly, when it comes to improving indoor air quality, there are, of course, at-home portable air filters. Although air cleaners are not regulated, the EPA does have a useful guide on how to select one. Look for HEPA filters to remove particles, and activated carbon filters to remove gases.
If you do use an at-home air filter, keep in mind that longer run times and faster run speeds generally increase the amount of air filtered, meaning, if you have concerns about air quality, keep it on high as much as you can.
Of course, many portable air filters are small and only have the capacity to filter a limited amount of living space. Thus, if you have only one, prioritize using it in the room you sleep in. And if you can, move it into the room you work in for that portion of the day, as well.
Take Home: Coronavirus and Air Quality: What do we know so far?
Early media reports suggest that emission levels of certain pollutants may be decreased due to shut downs and restrictions associated with COVID-19. Few peer-reviewed journal articles are published on the topic, but may emerge in the coming weeks and months.
However, even if there is a decrease in emissions, this is not necessarily a reason to celebrate. These decreases are temporary and come at the cost of human lives, and even at these reported lower rates, pollution levels are still high compared to previous decades.
Furthermore, the US has rolled by emission regulations during the COVID-19 outbreak.
As we spend more time inside, we can take steps to improve our indoor air quality by reducing the pollutants we bring into our homes, properly ventilating our spaces, and using portable air filters.
There is much to be learned about the COVID-19 response and its impact on the environment. In the coming weeks and months, when more data is available, perhaps we can revisit the question.
I hope you are well!
If you liked “Coronavirus and Air Quality: What do we know so far?” you may also like:
- What is PM 2.5?
- Food safety and coronavirus: What do we know so far?
- Some public health definitions to help you understand recent news and COVID-19