App reveals most polluted London Underground routes to travel on | Pollution

Like most Londoners, Tanya Beri has mixed views of the city’s vast underground rail network that carries millions of passengers every day on its 11 lines and through its 272 stations. The tube keeps London moving, though often in cramped, uncomfortable and unhygienic conditions.

However, Beri believes she has found a way to improve travel for concerned commuters. She has developed a phone app that can direct passengers to routes that offer minimal air pollution.

“The UK safe limit for healthy air is to have fewer than 25 small particles in a cubic metre of air,” said Beri. “In some places on the underground, it can top 200 per cubic metre. I want to help people avoid that.”

Studies have suggested that long-term exposure to fine particulates could be linked to increased rates of chronic bronchitis and increased mortality from lung cancer and heart disease.

Beri, 29, will be given one of Innovate UK’s Young Innovators awards at a ceremony this week for her work on developing the app. She will be among the 94 young entrepreneurs who will receive some £1.25m in grants to help them tackle some of biggest challenges facing society in Britain. Other inventions to be given awards range from cheap alternatives to plastic based on onion skins to a smart medication dispenser that promotes patient independence.

Beri’s app suggests routes that provide the lowest risk of breathing air with high pollution levels. “It’s like a TfL [Transport for London] or Google app but instead of offering the speediest journey between destinations it provides routes with the lowest air pollution,” she said.

An example is provided by a passenger from North Harrow tube station to Canary Wharf, part of London’s business district, said Beri. “If you go the quickest way, via the Jubilee line, then you face pollution that is about 220 particles per cubic metre. If you take the slower route and stay on the Metropolitan line, you will face pollution of about 50 particles per cubic metre. That is still over the safe limit but it is less than a quarter of what you would experience on the Jubilee line.”

Researchers have found the underground lines with the most polluted air are the Northern, Bakerloo, Jubilee and Victoria – because they are the deepest. By contrast, lines such as the Metropolitan, Circle and District have stations that are nearer the surface or are actually at surface level and so are better ventilated compared with deep lines where insufficient airflow allows particulates to accumulate.

In one study by scientists at King’s College London, it was found that particulate concentrations in trains on the Victoria and Northern lines were greater than those from studies of underground trains in Beijing, Guangzhou, New York, Barcelona and many other cities, while stations at Oxford Circus, Waterloo and London Bridge were rated as some of the worst on the tube.

As to the causes of the particulates that float through stations and trains, studies have indicated that most are generated as wheels, tracks and brakes grind against one another, throwing up tiny, iron-rich particles. These vary in size, with those under 2.5 micrometres in diameter – known as PM2.5 (particulate matter 2.5) – causing special concern. They can reach deep into your lungs and enter your bloodstream to be transported around the body, affecting other organs.

These are the particles to be monitored by Beri’s app, which will be launched later this year. She has also set up a company, CAIR, that will market it.

It was the problem of air pollution that attracted Beri to start researching her invention. “I used to commute on the underground,” she said. “And sometimes I got sick after travelling on it. So I thought it would be a good idea to find a way to help people who are worst affected by air pollution. Hence the idea of the app.”

Data about pollution levels at tube stations is stored electronically, and a starting point and destination are keyed into the app, which then produces the best low-pollution route for the traveller. “It is simple to operate – which is another key advantage,” she added.