Air-cleaning buses are being pressed into action in Southampton following a successful trial.
Passenger transport operator Go-Ahead is to fit a special filter to all five buses run in the city by subsidiary Bluestar.
The device sits on top of each single-decker bus and uses fans to suck polluted air past a specially designed filter that can remove up to 99.5 per cent of particles from the air.
Southampton was chosen because a World Health Organisation (WHO) report had warned that the south coast city was at the limit of unsafe air pollution.
Go-Ahead says the filter “exceeded all expectations for its potential benefit to the environment”, adding that for the test it was fitted to its latest-generation low-emission buses, which don’t pump out any more than 0.08g of nitrogen oxide per kilometre.
Chief executive David Brown said: “When we launched the air filtering pilot, we wanted to play our part in tackling the crisis in urban air quality and show that buses could be an answer to pollution in cities.
“We already know that a fully loaded double decker can take up to 75 cars off the road, reducing congestion and pollution, and now we have hard data showing that buses with the fitment of an air filter can actively improve air quality.”
Brown also encouraged local authorities to help roll the filters out at a faster rate.
The filters target the organic air pollutant PM10, which is generated by a number of urban sources such as vehicles and has been linked to cardiovascular illness and respiratory disease.
WHO reports that 4.2 million premature deaths worldwide are associated with outdoor air pollution.