Do we really need to spend £ 25million on air monitors to tell ourselves that opening a window is good for our health? – .

Do we really need to spend £ 25million on air monitors to tell ourselves that opening a window is good for our health? – .

For many years the poor quality of UK indoor ventilation systems escaped scrutiny. Then Covid happened. Despite the World Health Organization’s initial focus on fomites (hard surfaces), virtually all epidemiologists now agree that Covid is spread primarily through the air through respiratory droplets.

The main problem is that most indoor public spaces in Britain – like offices and schools – were simply “not built with a pandemic in mind,” according to Kelvin Williams, former president of British Occupational Hygiene. Society, who admits that many of the companies he works with have “never had to think about [ventilation] before. “

The story given by ventilation experts is that until the 1990s most UK offices were built with air vents in the floor, which essentially pushed air upward toward the ceiling. Then, with the introduction of high-tech heating and cooling systems, architects realized that it was cheaper and more energy efficient to reverse this system. In newer offices, the air is mostly pumped downward, from the vents in the ceiling, meaning the atmosphere, potentially contaminated with pollution and pathogens, is recycled rather than replaced.

This means that viral particles are now likely to reach the mouths and noses of many more people than they would with an old-fashioned ventilation system, Lipinski thinks – which is particularly bad news. in the event of a pandemic. “Visualize how [Covid particles] spread by imagining steam coming out of your mouth. Because it is much warmer than the ambient air, and therefore much lighter, it curves and floats towards the ceiling… and lingers there. Most ventilation systems will now pick it up, mix it, mix it around the room, and distribute it to everyone. “

In a study by Lipinski, using a mannequin exhaling virus-infected air into a large room, it took just four minutes for the ceiling grid ventilation system to spread it around every corner.

Williams says most modern ventilation systems were built with environmental goals in mind. Less thought has been given to the potential spread of respiratory viruses, he says – an oversight that may now change. “Surely we should revisit the way building regulations are written … to take into account a pandemic?” Let us learn the lessons.

Covid and other respiratory viruses like the flu are not the only worrying consequences of poor indoor air quality. The government estimates that between 28,000 and 36,000 people die each year from man-made air pollution (both outdoor and indoor), costing the NHS around £ 200million each year . Living or working in a polluted area means you are more likely to have a heart attack or develop a respiratory disease like asthma. Lung cancer is also a risk.

Prolonged overexposure to Co2 in a poorly ventilated building has been shown to make us lazy and reduce our concentration – “sick building syndrome” as the NHS calls it. Symptoms also include headache, sore throat, and dry, itchy skin. This “condition” is believed to reduce productivity, leading to a higher absence rate among staff.

So how do you purify the air? Since the start of the pandemic, offices, restaurants and bars in the UK have spent millions on air purifiers, described by manufacturers as the ‘seat belts’ of indoor air quality. But their effectiveness remains controversial. They usually only benefit people near the purifier, experts believe. Lipinski criticizes “snake oil sellers” who made profits by overstating the benefits of air purifiers during the pandemic. “If you think of a purifier… it blows air into the room at a certain speed. This air can then pick up the virus infected air and simply mix it [to the existing air]. There is very little chance that this virus-infected air will return to the purifier. [where it would be cleaned].  »

Others turned their attention to the Co2 monitors. In theory, Co2 monitors can tell teachers which rooms are poorly ventilated; if the Co2 levels rise too much, it suggests that the cool air is not circulating, which means that the Covid particles could also build up in the air.

Using Co2 as an index of air quality is “a bit rough and ready, but it’s the easiest thing we have,” says Williams. Questions have been raised, however, about what exactly teachers or office managers can do if they discover that a room is poorly ventilated. “Our high schools have 97 percent occupancy rates, so you don’t have any available classrooms,” says Dr Mary Bousted, co-secretary general of the National Education Union.

Instead, it seems like the best solution is to just open a window.

Studies, including a simulation of a classroom by experts at Harvard TH Chan School of Public Health, show that having a single window open, with a fan near the window to blow out potentially contaminated air, leads to considerably lower viral concentrations. Ironically, opening a window is actually quite difficult in many modern office and school buildings. “This is how crazy it is. Instead of using the easiest way to ventilate, we get super complex and mechanical, ”Lipinski explains.

Florence Nightingale, in other words, could have been right from the start.


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