A lack of air-quality monitoring and poor ventilation in schools is jeopardising the health of cleaners and our most precious asset – children. This reality frustrates Dr Gavin Macgregor-Skinner, senior director of the Global Biorisk Advisory Council (GBAC), a division of ISSA. He believes a simple starting point to fix the problem is to use indoor air quality (IAQ) monitors to test concentration levels of substances such as carbon dioxide, formaldehyde and nitric oxide.
“The monitors are of such high quality, they’re affordable and they’re real-time sensors that give us an opportunity to do our own citizen science research in classrooms,” Macgregor-Skinner says.
As schools battle to prevent health threats such as respiratory syncytial virus (RSV), whooping cough, pneumonia and COVID-19, IAQ is in the spotlight. Two recent analyses of 10 classrooms in five Victorian schools provide insight into the issue.
A 2023 study, reported in ScienceDirect, evaluated the ventilation of Australian schools and revealed that 60 percent of classrooms had ventilation rates “below the accepted minimum.” The study also noted that globally there is an “increasing tendency to introduce mechanical ventilation in schools to improve indoor environmental quality.” Another analysis, reported in the Architectural Science Review, found that students in Years 1 to 12 spent up to 1,075 hours indoors in school classrooms annually and that “poor IAQ can cause acute and chronic health effects, and vulnerable members of the community, such as children, are particularly susceptible to adverse respiratory effects.”
PROTECTING OUR CHILDREN AND CLEANERS
For Macgregor-Skinner, the message from such studies is clear for school building managers and cleaners. First, affordable IAQ monitors should become the norm to provide baseline data on air quality. “We’ve got so many solutions and tools,” he says. “With proper IAQ data, it will then come down to what we can afford to put into classrooms to ensure that children don’t have negative cognitive outcomes and other executive function disorders because of air pollution,” he says. “We need to help create healthy spaces for positive mental health outcomes.”
Cleaning surfaces is super important for controlling gastric infections, but is not necessarily successful for controlling airborne infections.
Second, he says greater focus is required on cleaning training to safeguard schools, which are susceptible to allergens and fine particulate matter such as dust mites, pollens, and mould. That includes insisting on removing mould from classrooms, not just blasting it with chemicals.
Dr Claire Bird, managing director of laboratory analysis and technical support group LITMAS, says infectious diseases are specialists in reaching the parts of our bodies that result in the greatest chance of successful infection. The two most common types in schools are respiratory and gastric infections. The former is transmitted through the air to reach the throat, chest, or lungs, while gastric germs collect on and are picked up off surfaces (typically through hands or food) and end up in the intestine.
Understanding that transmission process is crucial when considering cleaning processes, according to Bird. “Cleaning surfaces is super important for controlling gastric infections, but is not necessarily successful for controlling airborne infections, and it is here that we need to think about cleaning the air, by diluting it with clean air either from outdoors or from a specialised air filtration or cleaning device proven to adequately reduce infectious agents.”
She advises that paying attention to the ‘4 Ds’ – distance, density, duration, and dilution – as recommended by the Integrated Biosciences and Built Environment Consortium (IBEC), can make a difference. A common example where the 4 Ds lead to infection is having a sick child coughing, sneezing, or talking near to (close distance) a group of other children (high density) over the course of a whole day at school (long duration). “That scenario poses the biggest risk of transmission,” Bird says.
The key to management then becomes dilution, which can be achieved through providing appropriate ventilation in a classroom, either through ventilation or filtration of air, neutralising of the pathogen, or wearing of masks if infected.
Natural ventilation, such as using wind and thermal buoyancy to create air movement in and out of a building, is the only option for many schools that use split-air conditioners for cooling and heating. However, there are times when natural ventilation can prove challenging, such as if outdoor air is polluted by a nearby busy road or during bushfires or fire-reduction burns. By contrast, mechanical ventilation (such as air-conditioning or supplying fresh air into a building or room using ducts) often passes through filters or may have ultraviolet light in the system to reduce risks of infection.
“However, not all mechanical systems can operate properly with upgraded filters such as HEPA, so just changing a filter could diminish the quality of indoor air,” Bird says. Increasing the amount of outdoor air may lead to different risks, including intake of outdoor pollutants or changes in moisture levels in the building, which can lead to mould or a higher chance of becoming infected.
“If there’s natural ventilation and outdoor air is clean, then obviously you optimise that,” Bird says. “If there’s mechanical ventilation, you do what you can to make sure you’ve got the best possible filters in that system and that you supply clean air.” Using the wrong filters “can actually make things worse,” says Bird, who adds that another form of dilution is using face masks that minimise the spread of pathogens or even staying away when sick.
“Scientists advise a layered approach, which includes an appropriate cleaning regime.” She advises industry participants to get up to speed with the ASHRAE Standard 241 focusing on the Control of Infectious Aerosols, which calls for a strong focus on ventilation rates at times of high infection risks.
REMOVING MOULD AND OTHER HAZARDS
Cleaning schools presents several challenges for contractors, including the threat of mould. The spores can cause allergic reactions and respiratory problems, while some species of mould can produce mycotoxins that pose severe health risks. Scott McFadzen, a director of Coach8, a school offering Institute of Inspection, Cleaning and Restoration Certification (IICRC) training for the cleaning and restoration industry, says a lack of knowledge by some cleaners about effective mould removal in schools and other sites is problematic.
“They just haven’t got the experience or formal training with regard to mould remediation or any type of mould cleaning,” he says.
McFadzen agrees with Macgregor-Skinner’s view that removal of mould is the key, rather than relying on cleaning chemicals or fogging to temporarily minimise its impact. He notes that the latest guideline regarding mould – the ANSI/IICRC S520 Standard for Professional Mould Remediation (4th Edition) – makes it clear that source removal of mould contamination is “the primary means of remediation” and that “indiscriminate use of antimicrobials, coatings, sealants, and cleaning chemicals is not recommended”.
Bird adds the warning that cleaners can be particularly vulnerable to the health risks associated with mould and other particulate matter being released into the air from surface dust where it accumulates. One common example is when mould settles on “big horizontal surfaces” such as carpets and is then agitated when cleaners use vacuums, particularly those held on backpacks where air is discharged into their breathing zone.
“If it isn’t a true HEPA vacuum cleaner, cleaners are at much higher risk of being exposed than somebody who’s coming in there and sitting around when that surface isn’t being agitated.”
Bird cites a recent case at a school she and her team attended after a flood event. An initial spore test of the moulds most strongly associated with dampness – aspergillus and penicillium – recorded a count of 129 spores per cubic metre of air. That rose to about 5000 after people started moving around the room, but almost topped 60,000 when people lifted a carpet tile where mould had settled and grown.
The lesson, she says, is that cleaners and restoration experts must use the right type of cleaning cloths, vacuums, and other cleaning equipment to stay safe.
Those who are involved in any type of mould cleaning within a school or a public area need to have some type of training on how to assess the area, assess the conditions, understand what’s creating the problems, and then know how to fix it.
MAXIMISING THE IMPACT OF HVAC SYSTEMS
A key element of safeguarding school children from poor IAQ is having effective HVAC systems that can control surface dew-point temperatures within buildings. Again, McFadzen stresses the importance of having professionally trained HVAC specialists who are up to speed with the latest standards, including the IIRCS’s new S590 Standard (1st Edition) that addresses HVAC assessments after mould, water, and fire damage. It outlines procedures to perform HVAC assessments and create a written report and remediation work plan for residential, commercial, institutional, and healthcare buildings.
“Those who are involved in any type of mould cleaning within a school or a public area need to have some type of training as to how to assess the area, assess the conditions, understand what’s creating the problems, and then know how to fix it,” McFadzen says. “That’s a critical document that should be used and noted by those who are assessing HVAC systems, particularly for those working in schools.”
While he agrees that HVAC use and maintenance are crucial, Macgregor-Skinner says the truth is that retrofitting old buildings is expensive and therefore should not be the first line of defence. This should fall to cheaper air cleaners. “With the existing systems, upgrading them costs a tonne of money. If suddenly we’re saying that we want MERV 13 filters in all our schools, that’s not realistic.”
For cleaners and building managers entrusted with the task of managing the removal of pathogens, as well as handling IAQ threats, Bird acknowledges that it is a big responsibility. However, she is encouraged that there is an increasing focus on the importance of IAQ through a new charity called the Safer Air Project, which will be lobbying government for IAQ standards designed to allow everyone to safely enter buildings, regardless of their health status or vulnerabilities. Bird is one of several of the group’s expert advisers and believes the group’s initiatives will ultimately have positive flow-on effects for the cleaning industry.
“There’s a lot of really exciting things that are happening in Australia and overseas at the moment in this space. The future is
bright for safe buildings.”
Photo by alam kusuma on Unsplash.
At the 2024 ISSA Cleaning & Hygiene Expo:
Dr Gavin Macgregor-Skinner (Panellist)
‘What’s the Game Plan?’ – 11 September
Dr Claire Bird
Scott McFadzen (Panellists)
‘How to Track the Invisible’ – 12 September
Dr Gavin Macgregor-Skinner
‘The Dos and Don’ts of Cleaning Products’ – 12 September
Dr Gavin Macgregor-Skinner
‘Air, Surface, Water – The Trifecta of Cleanliness’ – 12 September
