Chris Birch used to dread late afternoon meetings at the old Stretford office of Hilson Moran, a Manchester engineering consultancy.
“You’d be sat in a meeting for three hours, feeling slightly headachy, tired and stuffy,” says Birch, the company’s head of sustainability.
Outdoors, when very polluted, you can see and taste and smell it. But indoors, you often can’t detect what’s there - Noakes
The windows in the conference rooms (and the rest of the office) were kept shut all year round; in winter to prevent the cold getting in and in summer to stop particulates, carbon dioxide and nitrogen dioxide from car exhaust fumes drifting in from nearby heavy traffic.
But sealing the building meant every breath an employee took during those long meetings would raise the carbon dioxide level in the room, causing drowsiness and headaches.
“The problem we had for 20 years was that when conditions in the office got stuffy or hot, you’d open a window for ventilation and be hit by a wall of noise and air pollution,” Birch says.
Obviously this workspace isn’t unique – nor is the experience of developing a throbbing head and even difficulty breathing as we go about our daily lives in offices.
Having air conditioning doesn’t help unless the system includes proper filters, as the outdoor air – potentially filled with pollutants – is sucked indoors and circulated around the office.
Yet there’s not great awareness of the issue. We all notice air quality in our outdoor environment but less so indoors. Cath Noakes, a professor at the University of Leeds’ School of Civil Engineering who has researched indoor air quality, says the issue has long been overlooked because “it’s a lot less obvious”.
“Outdoors, when very polluted, you can see and taste and smell it. But indoors, you often can’t detect what’s there. When people can’t see something, they dismiss it,” she says.
Yet they shouldn’t. The health impacts of poor outdoor air quality are well known – polluted air has been linked to respiratory tract infections, lung cancer and chronic obstructive pulmonary disease (COPD). A two-year study by medical journal The Lancet found that 6.5 million people die prematurely every year as a result of poor air quality. It also hits productivity - a 2014 study discovered that for every 10 micrograms of harmful PM2.5 particulates in the air, the productivity of pear pickers dropped by $0.41 per hour.
People often think the answer is to escape indoors – but that’s not true. According to the US Environmental Protection Agency (EPA), air pollution indoors is often between two and five times greater than outdoors – and can get at its extreme up to 100 times worse than the open air.
“Indoor air contains whatever pollution you have outside, plus whatever you are adding inside a building, like cooking and fumes from cleaning products and building materials,” explains Matthew S Johnson, chief science officer at Airlabs, which installs air filtering technology that removes 95% of air pollutants and harmful gases.
Most developments in indoor air cleaning have come from engineers in Asia, where fossil fuel dependency and weak regulation have created some of the world’s most polluted cities. According to World Health Organisation data released earlier this year India is home to 14 out of the top 20 worst polluted cities, with several Chinese cities also badly affected.
“China continues to lead the way with regards to indoor environment quality monitoring, in part due to the prevalence of outdoor air pollution across significant parts of the country,” says Matthew Clifford, head of energy and sustainability in Asia Pacific for JLL. “Aside from avoiding the negative impacts of poor air quality, improving indoor air has many positive benefits, including increased productivity, which has a direct impact on business bottom lines,"
In Beijing, which is known for its severe smog issues, a 2015 report by real estate firm JLL and environmental consultancy Pure Living found that 90% of office buildings were not achieving substantive reductions of pollutants on bad air days. But people are taking action. The number of air purifiers in China is rising substantially, nearly doubling in 2012-2013 – at a time when smog was particularly bad - then rising from 3.1m in 2013 to an estimated 7.5m by the end of 2018, according to Euromonitor. A report last year said manufacturers were innovating to meet demand, “using nanotechnology, increasing energy efficiency and reducing the noise levels”.
Firms and businesses are also seeing the benefits of investing. In their Beijing and Shanghai offices, for example, large employers including WPP and PriceWaterhouse Coopers have installed air filtering systems in a bid to retain good staff. The Cordis hotel in Shanghai, which opened in 2017, advertises among its amenities the fact that it has “the latest filtration system technology” which maintains indoor air quality within US EPA standards.
Innovation and awareness are also travelling outside Asia. Airlabs is installing systems in London shops after businesses recognised that levels of nitrogen dioxide inside stores on Oxford Street and Bond Street were similar to levels on the street outside. The first store to install Airlabs tech, which filters 1,800 cubic metres of air an hour, was Stella McCartney’s flagship shop on Old Bond Street.
At the moment there are no strict rules yet around the standard of the air we breathe in workplaces around the world, though the WHO developed guidelines in 2009 for indoor air quality. The US EPA provides “non-regulatory” guidance, while the UK’s National Institute for Health and Care Excellence is developing guidelines – not rules – for indoor air quality in UK homes. The guidelines are expected to be published next year, and the scope of the investigation indicates they will include potential interventions to remove sources of pollution and to introduce air filtering as standard.
Experts are unsure about the benefits of hard regulation. Simply setting a limit on the number of parts per million of troublesome pollutants allowed indoors can be arbitrary. Every building is different, and hard figures don’t account for office visitors whose breathing can push it above safe levels. “It’s something where there should be more accountability by bigger organisations that manage buildings,” says Leeds University’s Noakes. “But do you regulate it? That’s a difficult question.”
Luckily for those of us cooped up in offices every day, more employers are taking action. Philip Whitaker, the chief executive of AAF Flanders, the world’s largest air filter manufacturer, has said his company “see[s] enormous growth opportunities in Asia and in Europe with their increasing needs for air filtration”.
Chris Birch, and the rest of Hilson Moran, moved to a new city centre office building in Manchester a few years ago. It allowed them to design their workplace from scratch and to tackle the problem at source.
Airlabs is installing systems in London shops after businesses recognised that levels of nitrogen dioxide inside stores on Oxford Street and Bond Street were similar to levels on the street outside
Some actions were obvious: installing air filters that get rid of some of the most harmful pollutants. They also installed a number of air quality monitors that continuously check the levels of carbon dioxide, nitrogen dioxide and particulates in the air and raise a warning if they reach an unacceptable level.
The office also got a lot greener. “We looked at a piece of research NASA did that investigated plants that actively clean the air,” says Birch. They picked a handful of plants from a list of the top 10 most efficient and put them in their new office.
Then, says Birch, there was the “new car-like smell”. It’s produced by volatile organic compounds from paints, adhesives, furniture and carpets used in the building that leach into the air for several years in a process known as “offgassing”, explains Noakes.
To avoid this, Hilson Moran actively sought out low-pollutant materials for their furniture and fittings as certified by the International WELL Building Institute, which oversees the WELL Building Standard. Some fittings are even made out of potato peelings glued together with potato starch.
It was a difficult task. “A lot of the furniture and carpet manufacturers at that stage hadn’t yet got their head around it,” explains Birch. The company only had a couple of manufacturers of WELL Building Standard-ready items to pick from. But two years on, the number of manufacturers and the range of products they offer has increased.
Hilson Moran were so proud of their new office they submitted it for certification by the International WELL Building Institute. It passed the test, becoming only the third office in the UK – and the first outside London at that time – to do so.
At the same time, the company asked its staff to complete a standard worker wellbeing survey, using a common methodology called BUS (or building use studies). They’d done the same survey in the old office, where it came out in the lowest 10% of 650-odd other office buildings. “We did the survey again in this office and were in the top 2%,” he says.
“I don’t feel a tangible difference in the air quality,” admits Birch. But he manages to stay awake through those long, late afternoon meetings – headache-free, too.
If you liked this story, sign up for the weekly bbc.com features newsletter called "If You Only Read 6 Things This Week". A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.