6 Key Indoor Air Quality Issues in Schools and Childcare Centres

The Importance of Indoor Air Quality

Understanding the importance of indoor air quality (IAQ) and recognising the factors that can affect it can assist schools and childcares to provide a healthier and safer environment for all occupants. Poor indoor air quality has been linked to a large variety of health problems and can impact comfort and concentration for staff and students in learning environments.  IAQ has also been linked to airborne virus transmission such as the flu and COVID-19, with improvements in IAQ potentially mitigating the risks of transmission.

The implications of poor indoor air quality on virus transmission have led to the issue gaining traction around Australia, with experts believing that by improving IAQ in schools, the risks to staff, students, and the wider community can be limited. This comes at a time when outbreaks are occurring across the education community with more than 400 childcares and early learning centres across Australia temporarily closing or operating at reduced capacity due to outbreaks within the community. The risks to children in these environments have caused concern among parents with a survey conducted by The Parenthood finding that “66% of Australian parents don’t believe that it is safe for children to return to classrooms” during the Omicron outbreak of COVID-19.

Addressing the key contributors to poor indoor quality in schools and childcares can improve education outcomes and provide a safer environment for all.

What Impacts Indoor Air Quality?

Indoor air quality is impacted by a range of factors but there are 6 key issues that can be addressed in schools to improve the learning environment for staff and students.

Availability of Natural Ventilation in Schools

One of the overarching issues with indoor air quality in schools and early learning centres is the natural ventilation capabilities of each room. Natural ventilation is an important aspect of indoor air quality as it allows fresh air to circulate through a space and replace stale air and dilute the concentration of aerosols and virus particles within a space.

This issue is a common and can be caused by different factors such as the age and design of the building and size of the space, among others. If the space has been constructed recently, it is likely to be tightly sealed and thus have a reduced level of air flow. This is different from the natural ventilation in school buildings that were designed previously which are breezy and allow for air to circulate more readily but may also lack other ventilation considerations that are present in newer buildings.

Occupancy

With every breath we take, we supply our lungs with mostly oxygen and nitrogen from the outside air. When we exhale, we remove carbon dioxide, a by-product, from our lungs. Increased occupancy in a room correlates with increased concentrations of carbon dioxide in a room. If the air exhaled (by the room’s occupants) exceeds the room’s ventilation capability and there is no air dilution occurring, the concentration of CO₂ will build up leading to an increased risk of virus transmission.  

Activities

The activities undertaken in a space has a large impact on the quality of air within a room. The higher the intensity of the activity, the greater the concentration of aerosols exhaled and vice versa. Acts such as vocalisation – when speaking, shouting and/or singing which are common occurrences in classrooms or early learning centre settings will increase aerosolisation and therefore transmission risks of the virus.  

External Weather Events

Extreme weather events are becoming more common across Australia. This can impact the quality of air during events such as bush fires which release large volumes of smoke and reduce the air quality³. These events can prevent some indoor air quality improvement strategies, such as opening a window, from being effective and can exacerbate existing health conditions.

Inadequate Mechanical Ventilation

HVAC systems are a common form of ventilation within school buildings and many newer childcare centres, but it is important to ensure that they are helping and not worsening the air quality. The most important aspect in ensuring the HVAC system is helping is that it needs to be cycling fresh air from outside. Most heating and cooling systems recycle the air which can lead to issues with the air quality.

Inadequate filtration devices

Air filtration devices are a good option if a poor air quality has been identified within a space and other solutions are not appropriate. However, some options on the market can pose a risk to occupants and should not be used. The main issue is presented by filtration devices that utilise ozone. Ozone is associated with adverse health effects and may cause more harm than good. 

How to solve indoor air quality issues

Indoor air quality in schools and early learning centres is a common issue that can be relatively easy to address with the right knowledge. This can be done easily with a carbon dioxide monitor such as the ERS CO₂ Sensor with LiveSense Data Logging Platform. The plug and play sensor is designed to sit discretely on a wall inside classrooms and provides live data on the quality of the indoor air in each room it is monitoring, providing users with visibility as to whether corrective action is necessary.

Once an issue has been identified within a space, action can be taken to improve the ventilation within that room. This can be done simply by opening a window to increase air flow. However, on days with extreme weather or poor outdoor air quality, it may be impractical to open the space. Using a HEPA filter or increasing mechanical ventilation may be a better method to achieve the ventilation target during these events.