Covid gives us a chance to fix indoor air pollution forever

The pandemic taught us the benefits of ventilation in stopping the spread of the virus. But keeping our indoor air clean has plenty of other benefits

fix indoor air pollution

Germans love fresh air. The people of Germany love it so much that they have a name for the act of airing out a room: Lüften. It’s been called a national obsession: they’re known to throw open windows multiple times a day even in the dead of winter. And if we take anything from the past year-and-a-half, it’s that the rest of the world could stand to take a leaf out of Germany’s books, and crack open our windows too.  

While the early days of the pandemic were spent frantically sanitising surfaces and constantly washing our hands, the scientific consensus eventually settled on the fact that Sars-CoV-2 was airborne, and the focus shifted to proper ventilation to reduce its spread. 

But some scientists argue that we shouldn’t stop with those efforts when the threat of Covid-19 dissipates. Many have been clamouring for years that poor indoor air quality has been having massive detrimental effects on our health and productivity. And the pandemic may be the tide change. “It feels like The Great Awakening,” says Joseph Allen, director of the Healthy Buildings programme at the Harvard T.H. Chan School of Public Health. “Finally, the world has woken up to the importance of healthy buildings.”

We spend almost all our lives indoors – about 90 per cent, in fact. Take your age, multiply it 0.9, and that’s your indoor age, or how many years you’ve lived indoors. So the quality of the air you’re inhaling is pretty important. But for the most part, that quality tends to be poor. Indoor air can be packed full of harmful pollutants, which make us sick and hamper our productivity. “It’s influencing us constantly; I just don’t think people have thought much about it. And then when Covid hit, I think it opened a lot of eyes,” says Allen. 

Our buildings haven’t always been so stuffy. After the energy crisis in the 1970s, it transpired that our infrastructure wasn’t particularly energy-efficient; buildings were leaky, with heat spilling out of poorly-insulated walls. To fix this, architects made buildings smaller, a little bit more airtight. But this also entailed choking off air supplies and lowering ventilation. 

And so when the pandemic hit, it became harder to ignore how our stuffy buildings were negatively impacting our lives. While it’s now well-established that Sars-CoV-2 transmits through droplets in the air, it also has this in common with many other viruses, such as the cold and flu that travels around your office and schools every winter. 

What if we could stop that from happening? Bumping up ventilation and filtration rates in buildings could easily reduce the spread of airborne pathogens that regularly make us sick. In a May letter to the journal Science, almost 40 experts, including Allen, called for a “paradigm shift” in improving indoor ventilation standards to control the spread of infectious disease. “For decades, the focus of architects and building engineers was on thermal comfort, odour control, perceived air quality, initial investment cost, energy use, and other performance issues, whereas infection control was neglected,” they wrote. 

Air pollution is widely known to be a huge problem, causing millions of deaths every year. But what many don’t realise is that the outdoor air pollution is creeping past our doorways, too, meaning a lot of our exposure to air pollution takes place indoors. We’re often the culprits for creating our own pollution in our homes. Normal, everyday chores – cooking meals, cleaning the toilet – all release emissions of certain pollutants, from unvented gas stoves to organic solvents from household products. Smoking indoors, air fresheners and spray-on deodorants are all everyday sources of pollutants that can hang around in the air, worsening asthma and triggering allergy flare-ups. Indoor air pollution is thought to be responsible for four million deaths a year. 

And poor air quality isn’t just making you sicker – it’s also making you dumber. Allen and his colleagues published research in September on the relationship between indoor air quality and cognitive function. In the study, they kept tabs on over 300 office workers in urban commercial buildings in six countries including the UK – from between May 2018 and March 2020. Every participant got an air quality sensor on their desk and wore Fitbits to track sleep quality and physical activity, and meanwhile, their cognitive function was assessed using a mobile research app. Allen and his team found that the higher the concentrations of particulate matter and carbon dioxide in the offices, the slower the response times and the lower the accuracy. 

Everybody knows the feeling: a stuffy conference room makes you feel headachy and irritated. But it’s clear – and remarkably underacknowledged – that this translates into plummeting productivity levels too. “We’ve all had that experience of headaches or feeling tired in an office,” says Allen, “and we might blame it on a bad night’s sleep or lack of coffee or a boring meeting, which all contribute. But the reality is air quality is contributing in a big way as well.” This also means it’s bad for a company’s bottom line too: research has shown that sick leave increases by over 50 per cent amongst workers in poorly ventilated areas.

Like many issues concerning health, it’s a social problem too: those with the worst indoor air quality are probably the ones with the least capacity to do something about it. “When we’re thinking about improving our indoor environments, I think it’s really important that we think about how we enable people to get equal access to good air quality,” says Catherine Noakes, professor of environmental engineering for buildings at the University of Leeds. 

If that all sounds bad, it isn’t – scientists know how to fix it. In fact, they’ve known for decades, says Noakes. And the solutions are surprisingly simple. Opening windows, for one, is a simple temporary fix, but it doesn’t solve the problem of outdoor air pollution getting in. More advanced methods include mechanical ventilation and filtration systems, such as HEPA air filters which physically remove particles and pollutants from the air. 

While it’s pretty difficult to directly measure ventilation rates in a building, getting a carbon dioxide monitor is a great first step. Carbon dioxide concentration levels can act as a proxy for ventilation rates; if levels are high, then it’s likely that other pollutants are high too. In the UK, the Health and Safety Executive (HSE) sets the limit of carbon dioxide concentration in a workplace at 5,000 parts per million, or ppm, over an eight-hour period. And the HSE also has a guide to properly ventilating your office. But just because that’s the limit doesn’t strictly mean that it’s optimal or healthy – Allen’s research saw negative effects on productivity at levels below 1,000ppm. 

But cleaning up our indoor air will still take time and concerted effort. “We need to recognise this is the start of probably quite a long journey,” Noakes says. We know the science, and the guidelines in place are stringent enough, but “the biggest problem is compliance,” says Noakes. And we need to figure out how many buildings aren’t compliant with the standards. Under the Management of Health and Safety at Work Regulations 1999, employers are legally required to assess the risks to the health and safety of their employees and to put arrangements in place to control those risks. But the HSE rarely does checkups or prosecutes building owners and operators, says Timothy Sharpe, head of architecture at the University of Strathclyde. “The pandemic has made us realise that we don’t really know very much about quite a lot of our buildings,” he says. “We actually have very little data on how buildings are actually performing, what their ventilation levels are like.”

But the momentum from the pandemic means this could be the time to crack down on poor indoor air quality. Allen says this is the perfect moment to focus on the other benefits that come from cleaner indoor air beyond mitigating the spread of the virus. “When Covid eventually loses centre stage in our lives, we shouldn’t go back to forgetting about our buildings,” he says.