BUILDINGS CAN HELP FIGHT AIR POLLUTION
As the UK is warned by the Supreme Court that it must act to meet failing air pollution targets, Marley Eternit is urging the new Government to consider the use of photocatalytic technology on roads and buildings as part of its new air pollution plan.
The roofing and facades manufacturer suggests the UK could follow the lead of other countries such as Japan and the Netherlands by using the pollution absorbing technology to effectively ‘eat’ excess levels of nitrogen dioxide and nitric oxide (NOx) in the air.
Gavin White, product manager at Marley Eternit, explains: “The UK is in breach of its air pollution targets in 16 areas, mainly busy cities. The Government has been warned that it must reduce the amount of nitrogen dioxide (NO2) the UK produces and submit a plan outlining how it will do this by the end of 2015. The first area to address is clearly the polluter itself – mainly vehicles, particularly diesels. It is likely therefore that the Government plan will already include measures such as low emission zones, incentivising the use of cleaner technology in vehicles and reducing the amount of car journeys we make.
“However, if it only addresses the polluter, rather than the pollution itself, then the UK is missing a trick. A better option is to take a two pronged approach and also look to reduce the amount of pollution that is still being produced with the use of photocatalytic technology on our buildings and roads to absorb the toxic mix of NOx generated by road traffic exhaust fumes.
“It sounds incredulous but the technology exists right now to use photocatalytic coatings on roof tiles to ‘eat’ pollution from the air but we are the only manufacturer that does it. In fact, we launched our pollution eating roof tile, EcoLogic, back in 2007, which means not only is it readily available but it is also affordable and uses 50% recycled materials. It is already used by some local authorities on their housing stock to improve air quality in the local area.”
The external coating on Ecologic tiles contains titanium dioxide which speeds up the naturally occurring nitrogen cycle. The coating reacts with asthma-causing nitrogen oxides in the air to convert them to nitric acid, which is then neutralised to form calcium nitrate, a liquid fertiliser that is harmless to the environment (and, in fact, can even help to fertilise a garden). Tests show that the coating is expected to continue absorbing pollutants for around 25 years.
Gavin White continues: “Using typical data on pollution levels in urban areas, coupled with our laboratory test data, we estimate that over the lifespan of an average sized roof, the amount of NOx the tiles will remove could be equivalent to that emitted by a modern car covering over 100,000 miles. Indeed, we estimate that the tiles have already saved millions of miles in pollution since they were launched.”
The data from other applications of photocatalytic technology also backs this up. The technology is already used in cement on pavements in countries such as Japan, America and the Netherlands to cut pollution at the roadside. A study of busy roadways in the Netherlands found that photocatalytic concrete decreased NOx levels by 25% up to as much as 45% in ideal weather conditions.
Gavin White adds: “Using photocatalytic technology on just one roof has an impact on surrounding air pollution levels, but imagine the impact that thousands or millions of roofs could have. Why is there no grant or incentive for homeowners or developers to use technology on their roofs that can actually cut air pollution? In reality, vast amounts of NOx are being emitted into the atmosphere and although Ecologic tiles alone cannot eliminate this, they will make a positive difference to help reduce NOx levels. If the Government truly wants to make an impact on air pollution, it needs to make sure that its air pollution plan doesn’t solely focus on the polluter but instead does more to encourage the use of photocatalytic technology to reduce the pollution that is already in the air.”