Council plans to fight pollution with paving stones

Westminster Council is planning to make London only the second city in the world to tackle air pollution through nitrogen oxide-guzzling pavements.

The paving blocks, coated with titanium, are being successfully used in Japan’s second city, Osaka, and are due to be licensed in the UK. The stones were developed and manufactured by the Japanese company, Mitsubishi Materials Corporation, and work by absorbing NOx in a photosynthetic reaction and converting them into nitrogen and oxygen, with the help of an alkaline solution. These elements are then either stored in the stone or washed away. The process occurs in all weather conditions.

Councillor Frixos Tombolis, Vice-Chairman of Westminster’s Transportation and Highways Committee, announced on 3 October that trials of the stones would soon take place: “If they prove to be a viable option for Westminster they could prove to be a cost-free way of reducing pollution; not penalising car-drivers or business,” he told edie.

The councillor said that he first heard about the stones year ago in a magazine article. “When I was elected in 98 I remembered having seen an article about the paving stones in The New Scientist, which said that in trials they reduced nitrogen oxide levels somewhere between 10 and 20%,” he said. “I then decided to pursue the idea and so contacted Mitsubishi to try and arrange a free trial.”

“I hope the tests prove to be successful, and that we will soon be seeing these paving stones, not just in Westminster, but across the country. I have already had inquiries from interested cities in places as far away as China and Canada,” Tombolis continued.

Tombolis said that the council was looking to begin using the stones along certain areas of the council’s 400 miles of pavement in the spring of 2001. “The Transportation and Highways Committee will decide on the area to be covered which will begin with trials in locations beside our air quality monitors, but particular pollution hotspots, such as Oxford Street, will be primarily targeted”.

The Council is currently examining the pavement blocks, looking particularly at issues of durability and area density. Tombolis said that the paving stones were cost effective, at around £50 per square metre, they are priced midway between the cheapest and most expensive stones materials used at present. “If trials are successful, we will replace normal paving with these stones as resurfacing work is needed, making it very cost-effective,” he said.

“Mitsubishi Materials Corporation have informed me that they are researching NOx-converting road surfaces at the moment, which will be very interesting indeed,” he added.

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