Air Pollution and Respiratory Infections: Q&A
With the COVID-19 pandemic sweeping the country, you may be interested in learning whether exposure to air pollution might make you more susceptible to respiratory infections or cause your symptoms to be worse than they otherwise would have been. Following are some common questions and answers we’ve explored with respect to the link between air pollution and respiratory infections.
Question 1: If I’m exposed to air pollution, am I at higher risk of getting respiratory infections?
Answer: A variety of research studies have concluded that exposure to air pollution, both long and short term, may increase your susceptibility to respiratory infections. These studies demonstrate that exposure to air pollutants – including particulate matter, nitrogen dioxide, and ozone – increase susceptibility to both bacterial and viral lung infections because they interfere with immune defenses.
Question 2: If I have been exposed to air pollution and I contract a respiratory infection, will my symptoms be worse? Am I at higher risk of dying?
Answer: Chances are that, yes, if you have been exposed to air pollution and you contract a respiratory infection, your symptoms may be worse. The fact that air pollution (including smoking) contributes to heart and lung ailments such as asthma and emphysema has been well documented by decades of scientific research. It’s no secret that respiratory issues and heart attacks are highest when the air is dirtiest. It’s also no secret that people in vulnerable populations, including those with pre-existing health conditions, are more likely to exhibit worse symptoms from respiratory infections and may die in greater numbers because of it. The World Health Organization (WHO) attributes 26% of global respiratory infection deaths to air pollution.
Question 3: What about COVID-19 specifically? Can air pollution make COVID-19 symptoms worse?
Answer: It’s very possible that people living in more polluted areas may suffer worse symptoms and increased mortality rates for respiratory lung infections like COVID-19 than those living elsewhere. The Centers for Disease Control (CDC) has stated that individuals living in higher-pollution areas are more at risk for severe illness from infections, such as COVID-19, particularly if they have underlying medical conditions. Long-term exposure to air pollution contributes to the development of a number of chronic cardiac and respiratory illnesses, like coronary heart disease, lung cancer, COPD, and asthma, which increase the severity and risk of dying from respiratory infections.
Question 4: Can air pollution make it more likely that I’ll get COVID-19?
Answer: We’re less sure about whether pollution makes it more likely that you’ll contract the disease in the first place. In epidemic or pandemic situations, the population has no immunity. So, the main driver of getting a disease and dying from it is directly related to how much social interaction you have and not your exposure to air pollution. However, plenty of studies point to the fact that individuals exposed to air pollution are more susceptible to more common respiratory infections, and several research studies have shown a connection between air pollution and respiratory epidemic deaths (Spanish flu, SARS, COVID-19). Note that, while higher susceptibility of getting COVID-19 after being exposed to pollution is scientifically plausible, the studies regarding epidemic deaths used grouped data, not individual data, and therefore should be interpreted with caution.
Question 5: So, can viruses actually attach themselves to air pollution and be carried to individuals who become infected?
Answer: We don’t know that for sure. Some early studies have indicated that airborne pollution may be able to carry viruses over short distances, but the data is so far inconclusive.
Question 6: How does pollution compromise my body’s ability to fight infections?
Answer: Pollution can compromise your body’s ability to fight infectious diseases in a number of different ways. For example, cilia – the tiny hair-like structures that line the tubes of your respiratory tract – can become overwhelmed by pollutants, slowing or even stopping their ability to transport unwanted material out of the body. Another example is that macrophages – a type of white blood cell responsible for detecting, consuming, and destroying invaders like bacteria and viruses – are less efficient at removing pathogens that cause infectious diseases when they are working actively to clear the lungs of particulate matter pollution. Additionally, exposure to air pollution decreases the helpful production of cytokines – proteins that help regulate the immune system by acting as messengers between cells – and increases the production of inflammation-causing cytokines. Through these mechanisms, individuals exposed to air pollution may be more susceptible to infections and also fare worse once they have acquired them.
Question 7: How do I know if my air is polluted?
Answer: There are times when pollution accumulates near the ground and around buildings, making the air we breathe very dirty. You can observe the weather each day to determine when pollution is most likely to accumulate around your home, workplace, or school. Also if you live or work close to sources of pollution, you are more likely to be exposed to it. Low-lying areas, particularly valleys, are especially prone to accumulations of air pollution.
Question 8: Are there any resources available to tell me when my air is dirtier?
Answer: Yes, the Environmental Protection Agency (EPA) hosts the AirNow.gov website, which shows the current air quality and primary pollutants in your general location and predictions for tomorrow. Be aware, though, that the EPA air monitors are sparsely placed. Washington County, PA, for example, has only three monitors for the entire county. If you live within a mile of a major source of pollution – an industrial facility, a shale gas well, a compressor station, a chemical plant – your air is almost certainly worse than the EPA monitors are telling you.
Question 9: How can I know where these major sources of pollution are?
Most industrial facilities and manufacturing plants are well known in your local area. Ask around and you’ll find them. Others, like the location of oil and gas wells, are more obscure. FracTracker, for example, maps out all the oil and gas facilities emitting pollution in every county in the U.S.
Question 10: Can I measure the pollution in my air at home?
Answer: Yes, you can purchase monitors (costs are under $400) that measure particulate matter air pollution every hour or minute both inside and outside of you house. You can also go online and see current measurements from other people’s monitors.
Question 11: How can I reduce air pollution in my home?
Answer: Here are some steps you can take to reduce air pollution inside your home:
Avoid certain activities such as smoking
Keep your home as free of dust as possible since harmful gases and particles can adhere to dust particles
Vacuum using HEPA filters instead of sweeping with a broom to reduce airborne particles
Use an exhaust fan when cooking food
Purchase a HEPA-certified air purifier in your home
Keep windows and doors closed, especially during high-pollution days
Question 12: If I’m worried about contracting COVID-19, isn’t it important to know whether the virus is transported by dirty air to determine whether these steps are necessary?
Answer: Of course, but that answer will not be known for several weeks or months, and the hazard is present now. It’s most prudent to remove factors such as dirty air from your environment when you can. Another way to put it is this: There’s no evidence that cleaner air increases your risk that you will get COVID-19, so why not take steps that will benefit your health either way? Reducing your exposure to air pollution can improve your health in a number of ways, including reducing the risk of chronic conditions that make respiratory infections worse and priming your lungs to efficiently protect you against invading pathogens.
For a deeper dive into air pollution and respiratory infections, please see our literature review of scientific studies done to date, titled “Air Pollution and Respiratory Infections: Reviewing the Science.”