The silent killer: Indoor air pollution in schools and hospitals


Georgie Hughes examines how indoor air pollution is harming our most vulnerable in buildings which are supposed to be safe: schools and hospitals

We’re told that danger lies outside where we’re more at risk of pollution from cars, lorries and factories. But sometimes it’s in the very places where we feel most safe that the dangers lie. Much of air quality campaigning and research focused on these outdoor sources of pollution, so it’s easy to forget about the issues indoors. However, with 90% of our time on average spent indoors, we could be breathing in harmful pollutants and particulate matter without even realising.

people sitting on blue carpet

Vehicles, power plants and industrial activities are the most common sources of air pollution, but as these hazardous substances work their way into the atmosphere, they don’t just disappear. Pollutants can work their way inside buildings and are then trapped inside, creating unhealthy spaces, as poor ventilation means dirty air can’t be filtered out. Emma Rubach, Head of Health Advice at Asthma + Lung UK, explains: ‘Dirty air comes in many different forms, both indoors and out. In towns and cities, the main source of air pollution is road transport. Indoors, it comprises dust, dirt, mould, or gases in the air that could be harmful to breathe in, this could include chemicals in products such as carpet cleaners, paint and air fresheners, as well as fumes from cooking and woodfired stoves. Poor outdoor and indoor air quality has been linked to lung diseases like COPD, lung cancer, and an increased risk of heart disease and stroke, so it is a very serious problem.’

Even the places where we are meant to feel safest can pose a problem. Hospital buildings are usually located close to busy roads out of necessity to make them easily accessible. But this means patients are breathing in polluted air, as hospitals suffer from external pollution and particulate matter (PM2.5). A 2018 Asthma + Lung UK report found that more than 2,000 health centres are located in areas with PM2.5 levels above World Health Organisation (WHO) limits. This includes major teaching hospitals, clinics, GP surgeries and two of the UK’s biggest children’s hospitals – Great Ormand Street Hospital and Birmingham’s Childrens Hospital. The problem is widespread across the UK, with one in three GP surgeries and one in four hospitals in England in areas with unsafe levels of air pollution.

Rubach says this can pose a serious risk to millions of people who are already vulnerable, aggravating existing conditions or worsening acute illnesses. Hospital staff who work in these conditions are also at risk, exposed to high air pollution levels on a regular basis. She adds: ‘All air pollution is harmful to human health and can exacerbate lung conditions like asthma and chronic obstructive pulmonary disease (COPD), leading to life threatening asthma attacks or a flare-up of symptoms such as breathlessness, wheezing and coughing.’

To protect patients from these adverse health conditions, Matthew Perkins, Managing Director of air purification company MedicAir, says it’s important to properly ventilate indoor spaces, as the air within a space needs to be changed regularly to lower pollution levels. ‘In a medical environment generally, we will be looking to achieve 10 air changes per hour within those spaces,’ he says. ‘That’s the best way to keep patients and staff safe. Within a school or an office environment, we’re looking at three to five air changes per hour in those slightly lower risk areas.’ Hospitals require air changes more often as there are unwell people within these environments, with some spreading respiratory viruses and bacteria. Perkins, alongside two co-founders, designed MedicAir purifiers to specifically target all sources of indoor pollution. The purifiers have a combination technology that targets pollutants and VOCs with an activated carbon filter, while its UV-C light and anti-microbially coated HEPA H13 filter can eradicate bacteria and viruses.

MedicAir purifiers are now present in over 20 NHS Trusts, helping to clear the air in a range of environments where there’s close contact between patients and staff, such as wards, GP surgeries, dental practices and care homes. Not only has this benefitted patients by protecting their health, Perkins says he’s also seen the purifiers make a difference to staff wellbeing: ‘You see a decrease in staff sickness, increase in productivity, you see an increase in patients and staff feeling safe in those environments. There’s a huge amount of intangible benefits and improvements to the technology as well.’ Indoor air quality is growing area of concern, he adds, but it is difficult to address, as there is currently a lack of government regulation for indoor spaces. ‘Obviously from a government regulatory perspective, you can’t regulate what the air quality in someone’s house is like, you can regulate the outdoor quality,’ he observes. ‘I think it gets spoken about less because there is less of a kind of centralised responsibility for it.’

Schools face similar problems with air quality, as children and young people are exposed to harmful PM2.5 and pollution, affecting health and impacting academic performance – a Harvard study linked high air pollution concentrations with lower average academic test scores. John Lumb, Director at Evotech Air Quality, says Britain’s old building stock is part of the issue, as schools are in a poor state, with some even pre-dating the 1900’s. A huge government survey evaluating the condition of over 22,000 school buildings between 2017-2019 found that the estimated cost of remedial work to repair school buildings was £11.4 billion. ‘Our built environment is widely regarded as the worst in Western Europe because it’s the oldest,’ Lumb explains. ‘Now it’s creaking and it’s not really fit for purpose our schools.’ In response to the report, the government committed to rebuilding 500 schools over a 10-year programme, with funding earmarked for 400 projects so far. However, the Department for Education revealed in July that it had received more than 1,000 applications for the programme during a four-week application window in early 2022. This means that around 54.8% of applicants will miss out on funding, according to Schools Week. Lumb adds: ‘The amount of money that’s allocated by government is only scratching the surface in terms of repairs and rebuilds of new schools, but we can understand why there’s a lot of pressures on government and the Treasury. We can’t just go out and rebuild all of the schools.’

With progress on repairing schools slow, Lumb says he was concerned about the implications of leaving children and staff in unsafe school environments. Government data shows there are currently nine million schoolchildren and just under 600,000 teachers in the UK. Classrooms are typically highly occupied, with around 25-30 people in one room, while poor ventilation means there’s a mix of outdoor air pollution, PM2.5 and even airborne microplastics trapped inside. ‘There’s this ticking time bomb,’ Lumb says. ‘We’ve got all these kids going to school and yes, we’re giving them a good education compared to many countries around the world. But they are sat in polluted spaces.’ The team at Evotech decided they could help schools in the local area by monitoring air quality in classrooms and raising awareness of the dangers of indoor pollution.

The #CleanAirSchools campaign launched in 2021 and five Calderdale schools were fitted with sensors in playgrounds and classrooms to track CO2 levels throughout the academic year in a first of its kind study. This covered classroom hours only from September 2021 to July 2022, not including lunchtimes and bank holidays. With 9.2 million sensor readings, the results were staggering – the highest single CO2 reading was 5,966 parts per million (ppm), 4,466ppm over Department for Education guidelines of 1,500ppm. The total number of hours spent over these CO2 guidelines was a whopping 4,846, while sensors detected 57,999 CO2 alerts over 1,500ppm throughout the year. This means children are regularly exposed to extremely high levels of carbon dioxide in classrooms, a gas which is known to affect cognitive abilities, increase the risk of virus transmissions and cause kidney and bone problems. Improved ventilation is the solution to this, explains Lumb, but the problem is how can this be achieved on such a large scale with little funding available? Then there is the fact that outdoor air is often polluted with fumes from cars on nearby roads, so opening windows will not fix the issue.

Evotech is now monitoring levels of particulate matter in the Calderdale schools, starting from late 2022, to see how classrooms are affected by this throughout the year. The company has also been raising awareness of air quality in schools through presentations and a variety of resources. Children could track air quality using smiley faces using air quality whiteboards, with red, unhappy faces meaning high CO2 levels and green, happy faces representing low, safe levels of CO2. Lumb says we are starting to see the early signs of indoor air quality being taken more seriously, particularly in corporate environments that have brought in air purification systems on the basis of wellbeing. New building requirements introduced last June also require all new commercial buildings to have CO2 monitors in place. ‘It’s slowly trickling down,’ says Lumb. ‘But my worry is about the nine million schoolchildren.’ Both schools and hospitals are filled with the most vulnerable members of society who are already susceptible to the effects of pollution. It’s vital indoor air quality is improved in these environments, but how this will be achieved is still under debate.

This article was originally published in the March 2023 issue of Air Quality News


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1 year ago

Thank you, Georgie. Where Mr. Perkins says, “‘Obviously from a government regulatory perspective, you can’t regulate what the air quality in someone’s house is like, you can regulate the outdoor quality,’ I think he is mistaken – outdoor air quality is not regulated if he means controlled. How can it be? Where I live, in a rural county, we don’t even have any local air quality monitoring, not even in our towns. It is the same across many parts of the UK. Go to the list of government AQ monitoring sites on the Defra webpages, if you don’t believe me. I think one of the problems with so-called “dirty” indoor AQ is that the public has been encouraged by TV ads. to believe that scented chemical sprays and all sorts of wipes and liquids are the answer towards “cleaning” it up. People still think of air pollution as soot on blackened buidings years ago, or hazy air in photos and videos of overseas cities.They cannot imagine that the “lovely” scented candles they so like, or the furniture sprays and deodorant they use daily can also be a source of serious air pollution. Ignorance and denail rule. I read that perfumed chemical products have been banned in some hospitals in Australia, so maybe we could do tha heret, likewise in schools? But think what a fussd would be made, about the removal of “rights”?

A Mill
A Mill
1 year ago
Reply to  chris

I agree Chris. I have an extreme sensitivity to the scented chemical sprays and over scented laundry products that have become so popular over the last few years. A lot of shops, hotels and other businesses now use ‘scent marketing’ and diffuse scents that are so strong you can smell them down the street. I can’t walk around my town in the summer because of the over scented laundry hanging out or the plug in air fresheners escaping through people’s open windows. People who use these products can’t even smell them because you quickly become nose blind to them. And if you mention the impact of the air fresheners and scented wipes that are used in hospitals, the medical staff don’t understand why they make me so ill. Outdated trade secret laws mean that they don’t have to disclose the ingredients on the packaging so people have no clue what they’re exposing themselves to.

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