How can we redesign our cities and buildings to stop the spread of epidemics such as COVID-19? Chris Stokel-Walker reports
It’s eerily familiar yet very different. First we had SARS in 2002, which killed one in every 10 people infected. Then came the H1N1 “swine flu” epidemic in 2009, quickly followed by MERS (Middle Eastern Respiratory Syndrome) in 2012, and the Ebola epidemic of 2013 and 2016 that ravaged West Africa, killing more than 11,000. Now, a coronavirus, COVID-19, has spread worldwide.
The number and frequency of such super-epidemics appears to be growing pace, while seasonal flu remains a significant threat every year.
We’re all now realising that cities are a crucible for these sorts of illnesses. “What has been strange is that sometimes, diseases have been linked to certain places or buildings,” explains Joël Mossong, the head of epidemiology and microbial genomics at Luxembourg’s National Health Laboratory, who has been tracking the spread of COVID-19 with interest. (On 29 February, Luxembourg reported its first COVID-19 case – a man in his 40s who had recently visited Italy.)
The increasing commonness of these events shunts aside the notion that sick people can be hidden away in hospitals. COVID-19 and other illnesses don’t discriminate.
“It doesn’t pay attention to distinctions between spaces of health and spaces of everyday living,” says Geoff Manaugh, co-author with New Yorker writer Nicola Twilley, of an upcoming book on quarantines. “It does raise the question of whether or not that should be more of a design provision.”
So what can be done? How can we redesign our cities and buildings to slow or stop the spread of COVID-19? And what are the pinch points that perpetuate the virus’s existence?
“What’s strange is that sometimes [these outbreaks] have been linked to certain places or buildings”
Ben Dalziel, assistant professor at Oregon State University’s department of integrative biology, has studied the spread of flu-like epidemics across cities. Like COVID-19, flu is spread by the respiratory droplets an infected person exhales through a cough or sneeze, which then make their way into other people’s noses, eyes or mouths and infect them, too.
Dalziel and his colleagues looked at 603 different three-digit zip codes across the United States – each equivalent to a city – for six years as the areas went through the annual flu seasons. They discovered that the way in which they suffered from waves of flu differed depending on the city. Some areas saw almost all their incidents in a short period of time, right around the peak flu season; others had their incidents spread out throughout the season.
“We wanted to try to figure out why that was,” says Dalziel. Their findings were that several different factors were at play, including the climate of the city, the population density and where people live and work. The more humid the area, the more likely infected particles would persist for longer.
Dalziel and his colleagues began studying the spread of flu across cities when they realised that the rise of urbanisation and climate change could create a perfect storm. “An increasing majority of humanity lives in these big cities, where these key variables are going to start to interact,” he says. “We really need to think about cities as places where these factors are determining how epidemics play out, and it can make a difference.”
“What would an everyday suburban house or inner-city office look like if it was designed with healthcare in mind?”
Manuagh points out that “what is so interesting is that just so much of our interactions take place in artificially-designed spaces. Architects can do quite a lot to influence whether or not a disease might spread in certain circumstances.”
The challenge, of course, is that sometimes the best designs to stymie the spread of infectious diseases are the ugliest. But it is possible to design buildings to prevent the spread of illnesses – as anyone who has been in a modern designed hospital knows.
“One of the things that’s interesting and that comes out when we have a pandemic like coronavirus is the question of what would happen if architects focused on healthcare throughout the process?” says Manaugh.
He asks designers to answer a thought-provoking question: what would an everyday suburban house or inner-city office look like if it was designed with healthcare in mind?
The first outbreak of COVID-19 has been linked to a wet food market in Wuhan, China, while others have focused on the Diamond Princess cruise ship and Singapore’s Grand Hyatt hotel. The same situation was evident in the SARS outbreak in 2003, where air-conditioning systems around the Amoy Gardens private housing estate purportedly helped spread the illness in Hong Kong.
“Given that we’re living in cities and possibly in highly technical buildings with air conditioning, it’s likely that it could play a role,” says Mossong. He’s concerned that close contact – and recirculation of droplets through the air – can spread the virus quicker than otherwise would happen. “The more people you pack into close spaces, particularly indoors, the more it will facilitate the spread of diseases such as coronavirus.”
“Do I think people who plan cities are considering these challenges? I think it would be great if they were”
That said, Wuhan is not a densely populated city, by global standards. Its 8.3 million people live in a city of around 590 square miles, with 14,200 people per square mile. That’s five times less densely populated than Mumbai, the world’s most crammed city, and around the same population density as London.
Density starts to increase at pinch points such as office buildings, transport systems and places where people congregate, which are some of the areas about which the experts worry the most. “The aim is to reduce mixing between people and then you will reduce spread, because that’s how these things spread – direct contact between people,” says Mossong.
Dalziel’s research into cities shows that larger cities have a more prolonged, spread-out contagion period, while smaller cities have intense, spiky epidemics. The cause suggested was that as cities get larger, the way people move around and get in contact with each other becomes more highly organised.
“You get these patterns of pockets of high-population density, like the Tube,” Dalziel says. “That’s almost a defining feature of metropolises.”
That’s also a potential breeding ground for viruses. “It changed the way climate affects flu transmission,” he adds.
‘Specific humidity’ – the raw amount of water in the air – affects the transmissibility of the virus. The lower the humidity, the longer the flu virus remains in the air and the further the droplets can travel.
“If you picture an infected person having a cloud of risk around them,” explains Dalziel, “when the humidity drops that cloud expands out.”
But get close enough to someone who coughs and sneezes on you, or who wipes their nose and touches a surface, and the specific humidity matters less; you’re more likely to come into contact with dangerous droplets anyway. “That’s where those highly organised patterns of contact between people come in,” says Dalziel.
“When you’ve got spaces of circulation where people walk next to or pass one another, all touching the same things – whether it’s the gate to get into the subway or the handrails or the poles you might hold on to while on the Tube, they’re all germ-bearing surfaces,” explains Manaugh.
Ventilation systems in buildings that circulate the same air past different employees also cause concern. “You’re dealing with disease transmission vectors and concentrating people in those areas,” he says. “The entire thing is exposure.”
To counteract that, designers may have to think differently. They would have to avoid building communal spaces into their designs and think more carefully about air flows through buildings.
One of the ways quarantine facilities and biosafety labs prevent the spread of potentially harmful infectants in the air is to use negative air pressure between one room and another. This is costly, but the threat of mega-viruses spreading across the world may soon make it the norm for apartment buildings.
Focusing on interfaces and surfaces with which people interact is also another challenge. Facial recognition and the Internet of Things could do away with the need to push open doors or punch in access codes to get into buildings.
“If architects took it seriously as a design challenge, they could actually do it in a very beautiful and even unnoticeable way... we could live in a world as clean and safe as a hospital”
For architects and city planners who pride themselves on their skill in creating communal spaces where people can mingle and interact, the idea of self-isolation to prevent the spread of an illness is anathema. “Do I think people who plan cities are considering these challenges?” asks Dalziel. “I think it would be great if they were.”
Because it’s important. Every offhand meeting created by bringing people together, whether at a hot-desking workspace or a winding path through a park leading to communal benches, is an opportunity to transmit illness.
“The type of disease you’re dealing with is going to affect what design parameters you’d have to worry about in terms of public space, in terms of interiors, in terms of how close people get when they’re actually in social spaces and that sort of thing,” says Manaugh. But it’s important that we take lessons from this outbreak and previous ones and break down the barrier between healthcare provision and architecture in general.
In the same way that urban designers use computer modelling to look at how people and vehicles travel through cities, they should also track the spread of diseases through them and factor that into their designs. “You can absolutely do that,” says Dalziel, adding that the computational tools already exist. “One thing I think would be exciting to consider would be adding that to the portfolio of factors that are considered.”
It’s a challenge, but we need to nudge design to prevent and slow the spread of future epidemics like that of COVID-19. “If medical professionals had their way, hotel interiors would look slightly different in terms of how we keep guests from bumping into one another in hallways,” explains Manaugh.
Yet that isn’t practical in vast cities, particularly their transport networks. “I think metropolises are always going to have these high-density pockets, inescapably,” says Dalziel. But you can mitigate some of their greatest risks.
Some useful developments have already happened. Contactless payment systems on the London Underground and buses mean people don’t have to touch the same surfaces as others have. Touch-free sinks have reduced the likelihood of people picking up germs – although public bathroom doors that open without being touched are still seemingly a lifetime away.
But just because one thing worked for SARS or MERS, it doesn’t mean it will necessarily work for COVID-19 or Ebola. There’s no silver bullet.
“It’s a catalogue of dozens, if not hundreds, of smaller things that would help mitigate this,” adds Manaugh.
In part, we’re also limited by the boundaries of our knowledge of coronavirus. “We’re still unclear exactly about where coronavirus came from, precisely how it circulates and how long it lasts on surfaces,” he says.
But that shouldn’t limit our goals, he argues. “It might sound very dreary and slightly depressing to imagine the entire world redesigned as a kind of hospital ward,” he says. “But I think if architects took it seriously as a design challenge, they could actually do it in a very beautiful and even unnoticeable way that a generation from now would mean your children or grandchildren could actually live in a world that is effectively as clean and safe as a hospital.”