Pigeon Air Patrol takes to the skies over London to monitor air pollution levels

The pigeons monitor air pollution as they fly around the city using senors attached to their backs

Pigeons flock outside the National Gallery in London's Trafalgar Square (Scott Barbour/Getty Images)

A team of sensor-equipped pigeons has taken to the skies over London in order to monitor the capital's notoriously high pollution levels.

Pigeon Air Patrol, as the project is known, was created by Plume Labs, a startup currently crowdfunding the Plume sensor, a personal air quality monitor that can tell the user what levels of pollution they're being exposed to.

The birds in the Pigeon Air Patrol carry a similar device in a small and lightweight 'backpack', which constantly measures levels of nitrogen dioxide, ozone and other volatile compounds as they fly around the city.

Anyone curious to see the air quality in their area can tweet at the Air Patrol - they'll reply with an automated response, rating it on a scale of 'Fresh' to 'Extreme'.

Londoners generally aren't great pigeon-fanciers, but hopefully the fleet of helpful racing pigeons, a cut above their dirty cousins on the street, will help change some minds.

The project isn't intended to be a permanent solution to air monitoring in London - it's only lasting for three days, and is more concerned with raising awareness about the scale of the city's pollution problem.

Speaking to The Guardian, DigitasLBI creative director Pierre Duquesnoy said: "Most of the time when we talk about pollution people think about Beijing or other places, but there are some days in the year when pollution was higher and more toxic in London than Beijing, that's the reality."

Any attempt to improve air quality will be welcomed by Londoners. The city's legal air pollution limit for the whole of 2016 was breached by 8 January, and it's believed that London's poor air quality causes thousands of early deaths a year.

Calling London's pollution levels a "scandal," Duquesnoy said the project was aiming to make "the invisible visible".