Breathe easy: This new smart tracker gives your commute a pollution score

Mapping my evening journey, it lays out exactly where the peaks of pollution are on my smartphone-enabled Plume app.

On tapping the Flow device, a ring of LEDs light up to indicate the severity of toxic air in your immediate location: green for low, yellow for moderate, red for high, purple for very high.

Its battery last 24 hours and it measures nitrogen dioxide (mainly spewed out by generators and vehicle engines); volatile organic compounds (or VOCs — toxic carbon molecules from traffic, industry, cleaning and DIY products which can cause breathing problems); and PM10 and PM2.5 particulates (particles small enough to penetrate airways and cause harm).

The mechanism is clever: holes at the top — a “360 air intake’” — suck in air and run it through sensors. A laser band detects the quantity and size of PMs, while other pollutants attach to a heated membrane in the gadget, sparking a chemical reaction that can be accurately measured.

How accurately? David Lissmyr, founder and chief technical officer of Plume Labs, the team behind Flow, says its readings score well when compared with readings from the Environmental Protection Agency. In several weeks Plume is to publish figures to provide a more accurate comparison with the EPA’s fixed measuring stations.

So what’s the damage (to my lungs)? The stretch along Old Kent Road and into Peckham, where I live, scores “very high” — to be expected. Plume registers a “moderate” rating in the leafier climes of Kensington Gardens and St James’s nearer my office.

The pollution score is “low” on my route through Lambeth and Waterloo — which could be down to lighter traffic due to their inclusion in the congestion charge zone.

Undeniably, it’s disturbing to learn you’re breathing in toxic air. But Plume Labs’ idea is that a fleet of clean air detectives could lead to change. The data received from each device is drawing up a map, Lissmyr explains. “We’re working on developing this system that will give solutions to people by building a street-by-street description of air pollution, just like the Waze app or Google Maps map traffic. Measuring air pollution, like you measure temperature, will be something everyone does, and become second nature. It’s going to be much more mainstream than Fitbit.”

The argument goes that forewarned is forearmed when it comes to air quality data. Time of day and weather conditions impact the density of pollution, and therefore you can adjust your plans accordingly.

But how much can we do? People can take short-term actions, like choosing different routes to work, or longer-term ones, such as moving to a cleaner neighbourhood.

Daniel Read, a professor of behavioural economics at Warwick Business School, remains unconvinced: “The device might well detect tiny variations in pollution, but it would be irrelevant for practical or health purposes. In fact, I would worry people might even drive different, invariably longer, routes to avoid pollution ‘hotspots’ and create additional pollution in doing so.”

He points out that at a larger scale, the pollution maps for the UK from Government department Defra vary little from one urban area to the next. “Devices and apps like this are typically engaging for a short period, and then people become disinterested — think of Pokémon Go,” Read adds.

Yet he concedes Plume Labs are making an invisible problem easier to comprehend, and increasing awareness. “Perhaps people would then work to prevent pollution — they could drive less, for instance,” he says.

London is ahead of the curve in using technology to clean up its act. Later this year, a project using Google Street View cars will map out the city’s most polluted roads in order to help people choose cleaner routes. Two cars equipped with pollution sensors will spend nine months driving repeatedly around more than 1,000 miles of the capital’s streets to produce the most detailed data on air pollution in any European city.

From April, Mayor Sadiq Khan’s Ultra Low Emission Zone (Ulez) will tighten restrictions on vehicle pollutants in the congestion zone, making air cleaner.

But for now, I’ll go with the Flow.