Clean indoor air

Indoor air quality has attracted global attention due to increasing awareness of the negative impacts of airborne hazards. These include pollutants such as bushfire smoke, vehicle emissions and pollens, and pathogens such as airborne viruses, bacteria and fungi.

Burnet is leading critical efforts to improve indoor air quality and reduce exposure to airborne hazards including pollution, allergens, and viruses. Our work is aimed at generating an evidence base for acceptable, feasible and cost-effective models for indoor air quality monitoring, improvement and management. Our project ‘Pathway to Clean Indoor Air in Victoria’ brings together leading experts to develop evidence-based solutions for schools, workplaces, and public spaces, to support the management of indoor air quality in Victoria for enhanced health, economic and social benefits.

Australians spend 80-90% of their time indoors. The quality of the air we breathe outdoors is regulated, but the quality of indoor air is not. 

There are many well-recognised indoor air hazards, including air pollution and airborne diseases. Indoor air quality has significant impacts on health, cognitive function, and productivity. 

The young, the elderly, those with existing health conditions and those in marginalised communities suffer most from poor indoor air quality. This makes clean indoor air a fundamental requirement for an inclusive society. 

Workplaces have an obligation to provide a safe workplace for employees. Air quality is not excluded from occupational health and safety regulations. 

In 2024, Burnet began leading the Victorian Government’s Pathway to Clean Indoor Air Project funded through the Community Support Fund. 
  
The project will run for 2 years and aims to reduce the health, social, and economic impacts of indoor airborne infections and hazards. Air quality monitoring and low-cost solutions, including ventilation and air cleaning (filtration) interventions, will be tested in schools, workplaces, and public spaces. 
  
This world leading innovative project, led by Burnet, brings together a consortium of experts from various institutions to co-design and deliver the program of work, in partnership with the Victorian Government. Consortium partners include the University of Melbourne, Monash University, Training Centre for Advanced Building Systems Against Airborne Infection Transmission (THRIVE) and Amazon Web Services (AWS).

Indoor air hazards include pollution and airborne pathogens. 

Pollution 

Indoor pollution includes: 

• smoke from bushfires or wood heaters 
• vehicle emissions 
• pollens and allergens 
• gas from stoves 
• chemicals from paint, furniture and cleaning products. 

Even though most air pollution originates outdoors, being inside doesn’t protect us. Pollutants move freely through windows, doors and vents. Most of our exposure to outdoor air pollution happens when we are indoors. 

PM2.5 particulate pollution 

PM2.5 is the scientific name for less than 2.5 ug/m3 tiny airborne particles that can penetrate deep into the lungs and bloodstream. Sources of PM2.5 include smoke from fires and wood burners, vehicle exhaust and industry emissions. According to a 2024 study published in the British Medical Journal there is no safe level of exposure to PM2.5. Even minimal exposure causes an increase in hospital admission for cardiovascular disease. 

Airborne pathogens 

Airborne pathogens, including airborne viruses and bacteria, can easily transmit from one person to another in buildings that are poorly ventilated, with no air purification or disinfection systems. This has a major impact during pandemics and significantly contributes to the spread of endemic respiratory illnesses such as seasonal influenza, tuberculosis, and common cold viruses. 

Climate change and indoor air quality 

Climate change is increasing the frequency of events that impact indoor air quality, such as: 

• bushfires, which cause smoke pollution 
• floods, which cause dampness and mould. 

Clean indoor air can improve people’s health and cognitive function. It can also prepare us for future pandemics. 

Schools can benefit from improved academic achievement, an inclusive environment for students with asthma, and lower absenteeism due to illness. 

Businesses can benefit from improved productivity and staff taking fewer sick days.

Health

Our short-term and long-term health is directly impacted by the air we breathe. Poor air quality can also exacerbate pre-existing diseases and interfere with the treatment of other conditions, including cancer. 

Recent studies have found an association between poor air quality and the 10 leading causes of death in Australia in 2022: 

• coronary heart disease 
• dementia, including Alzheimer’s 
• COVID-19   
• cerebrovascular diseases   
• lung cancer 
• chronic lower respiratory diseases 
• diabetes 
• bowel cancer 
• blood and lymph cancers 
• urinary diseases.

Australia needs a comprehensive public policy approach to improve indoor air quality across all buildings. Policy leadership is essential to establish appropriate standards for new construction and to develop strategies that improve air quality in existing buildings.  

Many other nations have already taken actions to improve indoor air quality, including implementing regulations, standards or guidelines for building design and operations. 

In Australia, the Victorian Government’s Pathway to Clean Indoor Air in Victoria is an example of a program aiming to build evidence and knowledge to help guide policy change.   

There are key actions that will accelerate the pace of change:

Develop indoor air quality frameworks 

Recent scientific consensus published in 'Science' by Morawska et al in March 2024 provides important evidence for policymakers. Their review of air quality factors including PM2.5, carbon dioxide, carbon monoxide and ventilation rates offers valuable insights for developing appropriate policy frameworks. Clear guidelines or standards would enable coordinated action across sectors.  

Educate the community 

A clean indoor air campaign would increase public awareness of the importance of clean indoor air. An informed public should understand simple measures of indoor air quality and know what actions to take to improve it.  

Monitor and display indoor air quality data 

CO2 monitors should be installed in shared indoor spaces. This should start with high priority settings, such as hospitals, schools, childcare centres, aged care facilities, disability services, public transport, workplaces, and retail precincts. Employees, consumers, school children and their families should be informed about the quality of the air in these settings and know the actions they can take to improve indoor air quality. 

Implement engineering solutions 

Refreshing the air or purifying air can be achieved using well established techniques and technologies, including: 

• natural ventilation, such as opening windows and doors and modifying window configuration to improve air flow
• mechanical ventilation: airflow controlled by Heating, Ventilation and Air Conditioning (HVAC) systems
• air purifiers that clean the air by passing it through several filters that can remove dust, viruses, bacteria, smoke particles and dangerous gases
• Germicidal ultraviolet light (GUV), which inactivates bacteria and viruses in the air. Burnet Institute is investigating how effective GUV is for disinfecting air and reducing COVID-19 infection in Victorian residential aged care facilities.

Governments, schools and businesses around the world are recognising the benefits of clean indoor air and investing in a range of programs.