What we measure: Virus risk indicator

Marie Bannister
November 18, 2020

 

Viruses have always been part of our everyday life. With close proximity to one another in schools, offices and workplaces, viruses can easily be passed from person to person. 

Recently, the global pandemic has pushed indoor air quality to front of mind. Air quality plays a huge role in reducing the risk of airborne transmission and virus survival rate. 

Schools, offices and other commercial buildings can stay one step ahead of their virus transmission risk by seeking help to create indoor environments where people thrive but viruses don’t. We want to help create buildings where people thrive, but viruses don’t.  Contact Airthings for Business today.

Of course, measuring virus particles in the air in real-time is currently impossible. Certain indoor conditions and combinations however, can encourage or discourage virus transmission. Carbon dioxide, temperature and humidity play a big role in this, keep reading to find out how.Virus_factors_transparent-2

Contents:

How do viruses spread in offices, schools and workplaces?

Each virus is different, but one common way they can spread is airborne. In fact, there are often three main transmission routes;

Transmission_route_colour-2Droplets. Released through sneezing or coughing .

 

 

Transmission_route_colour-1Surface contact. Via hand-to-hand, hand-to-surface contact.

 

 

Transmission_route_colour-3Airborne Micro-droplets. That can stay airborne for hours and can be transported long distances1.

 

 

We focus on many different things at Airthings, but the Virus Risk Indicator focuses on the third. This is via microscopic airborne droplets, larger droplets through sneezing or coughing, and surface contact2. Distancing and cleaning habits can help mitigate two of those, but what about the tiny droplets we can’t see? They can be microscopic droplets which can stay viable in the air for periods of time and travel long distances, so how can you mitigate this risk?

Understand your risk

Understand-risk-icon_2

By monitoring the air you can understand which areas in your building have elevated airborne virus transmission risk. Different areas might need a different approach, and data is needed to plan preventive measures.

Take action

Alerts-icon_2Know what to do and where using virus risk insights and risk analysis reports in the Dashboard. With continuous monitoring you can check that your methods are working, and receive alerts when your virus risk creeps up.

Put people at ease

at-ease-icon_2Indoor air quality monitoring helps you keep in line with new and emerging recommendations. Do what you can to create a safe environment for building occupants, and show them that you’re prioritizing their health. 

How can CO2 impact virus transmission?

As we breathe out, our body expels carbon dioxide. In tightly enclosed meeting rooms, school rooms or workplaces, high CO2 levels could indicate that there are too many people in a room. Consider this situation when no fresh air is circulated, it could create a ‘breeding ground’ for virus spread.  Too many, are expelling CO2 from their breath in a small, poorly ventilated space. 

As a result of this, carbon dioxide regulations are becoming more and more common in the workplace, and especially, in schools. 

In the Netherlands, the government has introduced new measures, a ‘task force’ even, to ensure sufficient ventilation in schools3. They have created a basic measuring system and asked most education boards to participate. It shows that they are making the air quality a top priority, as its impact is evident. 

Similarly “the German government is investing €500m (£452m; $488m) in improving ventilation systems in public buildings to help stop the spread of coronavirus”, as reported in October 20204. This does not only include schools, but air circulation improvement in public offices, museums and theatres too. Part of the funding is available for CO2 sensors, which help indicate when the air in a room is unhealthily stale.

CO2 levels must be monitored and factored into any comprehensive air quality system, to ensure that a space is not poorly ventilated or over populated. Virus_factors_transparent-1

We want to help create buildings where people thrive, but viruses don’t.  Contact Airthings for Business today.

How can humidity and temperature impact virus transmission?


Do you know why we have flu season in the winter? We have a ‘flu season’ due to the changes in our climate  that increase the virus survivability and reduce our immune defence. Both of which are  affected by low temperatures and low humidity. 

In fact, studies have established a link between the facilitation of seasonal respiratory virus transmission, particularly flu, and the level of humidity in the air. Research for the Centre for Disease Control and Prevention found that when humidity levels were set to a low 23%, a huge 70.6-77.3% of the flu virus particles were able to cause an infection; even an hour after coughing6.  

pencil_with_line (1)In the controlled setting, when humidity levels were raised, the percentage of infectious particles dropped. In fact, raising humidity levels to 43% reduced the percentage of infectious particles to just 14%7. When humidity levels are too low, it means indoor air is dry, which can allow airborne microdroplets and bacteria to stay airborne longer and travel farther.

Similarly, Yale University’s research found that low humidity physically impairs the barrier functions in study participants bodies, which serve as a innate resistance against influenza infection8. Essentially, the low humidity in the controlled setting impacted the body's natural defences against viruses. 

Temperature’s impact on virus transmission is correlated with humidity. Cold weather can often lead to dry conditions inside, and when humidity levels become too low, viruses stay viable longer in microdroplets, thus spreading easier. This, amongst other things, means that humidity should be a considered factor in analyzing virus risk in the workplace.

By monitoring humidity and temperature indoors, you can make adjustments to help your employees’ immune system fight off infections. Clouds  (1)

We want to help create buildings where people thrive, but viruses don’t.  Contact Airthings for Business today.

How does the Virus Risk Indicator work? 

Virus_badge (1)Measuring airborne viruses in real-time is currently impossible, and probably quite alarming. What would be better is to ascertain how easily a virus can stay infectious spread in the workplace. Thankfully, workplaces can now harness the power of comprehensive indoor air quality solutions to gauge their risk of virus transmission. 

The Airthings Virus Risk Indicator combines data from Wave Plus for Business’ existing sensors that monitor CO2, humidity, and temperature into a proprietary algorithm, calculating the risk level of virus transmission in a building. 

It evaluates four risk factors that correlate with airborne virus spread: virus survival rate, the body's natural defence, room occupancy, and ventilation rate. It promotes indoor environments where people thrive, but viruses don’t.

The built-in sensors within Wave Plus for Business include Radon, CO2, VOC, Temperature, Humidity, Light and Air Pressure. The Virus Risk Indicator operates through a custom-developed algorithm that uses some of these sensors to analyze the relationship between the device’s indoor air quality readings and the most common factors that contribute to airborne virus spread in an indoor space, such as a school, office, or place of business. 

virus_closeup-1

These risk factors are as follows:

  • Virus Survival Rate: How long the virus can survive in the air.

  • Body's Natural Defences: How receptive/vulnerable the human body and immune system is to virus infection. Based on research of humidity levels, low humidity levels impair the body’s immune system, making people more vulnerable to airborne viruses.

  • Occupancy: In classrooms or meeting rooms with elevated CO2 levels the air exhaled by one person is inhaled by another as the air is not changing quick enough. Reducing the occupancy in closed spaces and giving the room time to “breathe” between use can help.

  • Ventilation Rate: How much fresh air is being brought into a space, a key factor for curbing indoor spread.

A few things to consider

At a time like this, transparency is key. At Airthings we want to be upfront about all the things our indicator can and cannot do. This will enable you to get the perfect solution for your business. Here are three things to consider about the virus risk indicator:

  • Addresses only selected transmission routes: The Virus Risk Indicator only takes into account the microdroplets that stay in the air a long time and can travel long distances indoors. It does not look at other factors such as surface contact and sneeze droplets which are much larger and naturally drop to the ground after 6 feet.

  • Cannot stop virus: The Virus Risk Indicator doesn’t stop or kill viruses in a building, but it gives an indication of how high the risk of airborne transmission is. This lets you take action to help mitigate the risk of airborne microdroplets passing from one person to another.

  • Does not act as a COVID-19-specific indicator: The Virus Risk Indicator can be used for all airborne viruses, such as flu, and isn’t only applicable for COVID-19.

Airthings for Business office  eGuide

 

 

Sources:

1. rehva.eu/fileadmin/user_upload/REHVA_COVID-19_guidance_document_V3_03082020.pdf

2. cdc.gov/coronavirus/2019-ncov/more/scientific-brief-sarscov2.html#:~:text=Airborne%20transmission%20is%20infection%20spread,and%20time%20(typically%20hours).

3. lesopafstand.nl/lesopafstand/richtlijnen/ventilatie/

4. bbc.com/news/world-europe-54599593

5. bbc.com/news/world-europe-54599593

6. journals.plos.org/plosone/article?id=10.1371/journal.pone.0057485

7.journals.plos.org/plosone/article?id=10.1371/journal.pone.0057485

8. pnas.org/content/116/22/10905