Since the first days of the pandemic, we've continued to learn more and more about COVID-19, including how it spreads and how to protect ourselves.
When it comes to spread, in particular, experts have hypothesized for many months that this new coronavirus may be airborne. But what does this mean? And — most importantly — does it change the preventive measures needed to keep you and your family safe from COVID-19?
To understand whether or not COVID-19 is really airborne, as well as what this means for our health and safety, we spoke to Dr. Tim Connolly, pulmonologist at Houston Methodist.
Q: What does airborne mean?
Dr. Connolly: We all know by now that viruses can be passed from person-to-person via handshakes or touching contaminated surfaces (and then touching your eyes, nose or mouth).
When it comes to viral spread through the air, however, it's a bit more complicated than you may think. There are two principle modes of air-based spread of viruses:
- Respiratory droplets
- Airborne transmission
Respiratory droplets are little balls of saliva and moisture, potentially containing virus such as COVID-19, released from your mouth and nose — flying forward into your immediate area when you speak, cough or sneeze. These droplets don't travel very far, however, and are generally caught by even a simple face mask. During the pandemic, the logic behind mask-wearing and social distancing of at least six feet is principally to control the spread of COVID-19 via respiratory droplets.
To be considered airborne, a virus must be able to remain in the air for a longer period usually by clinging to much smaller particles of water vapor or dust. If you've ever seen dust hanging in the air when walking into a sun-lit room, an airborne virus can hang glide on these dust particles in a room for up to three hours at a time. Viruses lingering in the air can gain entry into your body through your eyes, as well as your nose and mouth.
Q: How airborne is COVID-19?
Dr. Connolly: According to recent updates issued by the CDC, there's increasing evidence that COVID-19 is airborne in certain situations, particularly in enclosed, poorly ventilated spaces.
In addition to the simple acts of talking, coughing and sneezing, other common activities that can encourage the new coronavirus to become airborne include:
- Vigorously exercising at the gym
- Singing at a religious service
- Cheering at a rally, sporting event or concert
The airborne nature of COVID-19 may help explain the dramatic spread of the infection through certain environments, including cruise ships, nursing homes and prisons. It also explains why 22% of the recent spike of cases in El Paso, Texas, have been traced back to "big-box" stores.
While visiting a store, if enough individuals who are carrying the virus fail to wear masks — even simple, cloth-based ones — any airborne viral particles generated can then linger in the enclosed indoor space. Over the next several hours, unsuspecting customers who pass through this cloud of virus may ultimately become sick.
In a medical setting, several procedures can also encourage the virus to become airborne, including: nebulizer breathing treatments for asthma or COPD, CPAP machines for sleep apnea, and any medical interventions involving a patient's airway, such as placement of a breathing tube for surgery, bronchoscopy or tracheostomy. Whenever medical practitioners are involved in aerosol-producing procedures, N95 masks and other complete personal protective equipment (PPE) are absolutely essential.
Q: What precautions can help prevent airborne spread of COVID-19?
Dr. Connolly: The simple preventive measures public health professionals have been emphasizing since the start of the pandemic are still far and away the most effective ways to prevent getting sick with COVID-19.
These safety practices include:
- Social distancing of at least six feet whenever possible
- Limiting exposure to (or extended duration within) any public indoor environments, such as bars, restaurants, religious buildings, gyms and grocery stores
- Avoiding visiting with someone inside his or her home (spending a short amount of time with someone outdoors is generally safer)
- Wearing a mask!
With the realization that the coronavirus can potentially linger in the air for hours and also infect via your eyes, it's best to cover as many portals of entry as possible especially when walking in public spaces. For instance, when my family and I go out in public to the pharmacy, a coffee shop or gas station restrooms on a road trip, we wear masks and simple clear glasses. Similarly, when my kids walk the hallways at their schools, they wear masks and protective eyewear.