How can healthcare professionals help reduce indoor air pollution and the subsequent transmission of airborne viruses?

21 Apr 2022

Monitoring indoor air quality (IAQ) should be first on your list, as when you know what’s in the air you breathe you can take appropriate steps to improve it and then monitor the effectiveness of actions taken. 

Whilst high levels of CO2 indicates that a room needs additional ventilation, there are other pollution elements that should be addressed, and which may become regulated in the near future. In fact, in September 2021 the World Health Organisation (WHO) adjusted almost all of its air quality guidelines downwards, slashing recommended safe limits in some cases by 75%, and warning that exceeding the new levels would pose significant risk to health. Poor air quality, especially Particulate Matter (PM1 and PM2.5), has the ability to penetrate the lungs, enter the bloodstream and cause respiratory and cardiovascular morbidity and disease.

Recent studies of COVID-19 in several countries identified links between air pollution and death rates, and more recent research has concluded that a small increase in air pollution leads to a large increase in the COVID-19 infectivity and mortality rate in England. Public Health England states in its report, ‘Estimation of costs to the NHS and social care due to the health impacts of air pollution’ that long-term exposure to particulate air pollution is estimated to have an effect equivalent to 29,000 deaths a year in the UK. In addition, the total NHS and social care cost due to PM2.5 and NO2 combined in 2017 was estimated to be £42.88 million (based on data where there is more robust evidence for an association), increasing to £157 million when diseases are included where there is currently less robust or emerging evidence for an association. These costs are estimated to rise to £8.3 billion by 2035.

It will take time to reduce air pollution and these harmful airborne pollutants can build up quickly in poorly ventilated spaces, causing indoor air pollution to be up to five times higher than that outside. And, as a quarter of hospitals and a third of GP surgeries in England are located in areas that exceed safe levels of air pollution, it is important to monitor indoor air quality. Using IAQ sensors that monitor multiple air pollutants in addition to CO2, allows building occupants to tackle other sources of pollutants that can be damaging to health, and that assist in the airborne transmission of bacteria and viruses.

It is recommended to keep CO2 levels around 800ppm in healthcare settings which indicates a space is well ventilated, however, where readings are consistently over 1500ppm, action should be taken to improve ventilation. 

In our quest for energy efficiency and a reduction in carbon emissions, we have made our buildings more air tight, preventing natural ventilation. In short, many of our buildings simply cannot breathe! Of course, many healthcare buildings bring in fresh air through mechanical ventilation units, and now the latest state of the art systems can automatically adjust airflow to suit the specific needs of rooms and zones, via building management systems, when they are linked to a network of air quality monitoring sensors. For older systems air handling units should be set to maximise outdoor air over recirculated air. It should be noted here that, some AC units only recirculate air and do not add fresh air to the mix. If your building has this type of system you should look to upgrade and follow the guidance below in the meantime. 

Years of austerity measures has left the NHS with a mix of world-class, state-of-the-art facilities and Victorian hospitals no longer fit for purpose. In fact, in 2020/21 it was estimated that the total cost to eradicate backlog maintenance for the NHS estate was £9.2 billion. 

Modern facilities within the NHS estate and other healthcare facilities are likely to have more than adequate mechanical ventilation systems, however, older buildings in many circumstances do not have this luxury. Many struggle to meet the NHS ventilation guidelines of six air changes per hour in wards, and other areas like offices and meeting rooms, outpatient clinics and waiting rooms, often have no means of ventilation apart from the opening of windows.

In these instances, high quality air purification and sterilisation units can remove contaminants from the air, including bacteria and viruses, making for safer indoor spaces. They cannot, however, reduce or remove CO2, so it’s advised to open windows regularly, avoiding rush hour at both ends of the day when CO2, NO2 and PM levels increase near busy roads. The introduction of fresh air will reduce CO2 which can be detrimental to health in its own right, and the filtration units will deal with other pollutants including PM, NO2, VOCs, mould spores, bacteria and viruses. 

Air purification unit should incorporate a HEPA13 filter, that will capture 99.9 percent of particulate matter down to 1µg/m³ (micrograms per cubic meter of air), and a high grade activated carbon filter to reduce chemical pollutants (VOCs), NO2 and other gases. Some units also use UV-C light to kill 99.9 percent of airborne bacteria and viruses by damaging molecules in proteins, and these are particularly useful in a healthcare setting. The air change rate should be around six air changes per hour for the size of the space.

To support healthcare providers Evotech Air Quality is offering NHS organisations a free 12 month trial of the award winning Airthings sensors, with no obligation to buy. And, as it’s a scalable solution, any number of WiFi units from the range of sensors can be added at any time. 

Evotech is exhibiting at the Infection Prevention and Control Conference next week at the National Conference Centre in Birmingham. Visit us on Stand 9 in the Britannia Suite where we’ll be showcasing the sensors and can answer any questions you may have.