Innovative solutions to the problems of airborne pollution in cities

Particulate matter (PM) is an airborne pollutant, the smaller fractions of which penetrate the deep lung and can pass into the blood stream. It has a severe impacts on health along with oxides of nitrogen (NOx), as a report on London’s air pollution published this week have yet again confirmed:

‘Air pollution in London caused early deaths of 9,500 people in a single year’.

The EU are looking for technical solutions to help reduce the concentrations of pollutants in the ambient air. In this case Particulate matter (PM), which I have a specific interest in. The Horizon Prize on materials for clean air will be awarded to the most affordable, sustainable and innovative design-driven material solution that can reduce the concentration of particulate matter in urban areas.

So, anything that helps to reduce people’s exposure has to be investigated, with the caveat that ‘dealing with the pollution at source is the first priority. With that in mind the recent publication of Sustainia’s document detailing the  ‘100 most sustainable innovations of 2015‘ also deserves serious consideration. Innovations covers a number of sectors including buildings, cities, food and health.

​Encouraging and motivating innovators to get on board with the sustainability agenda and the pursuit of sustainable solutions seems a positive step. There are some prestigious names and organisations leading this work. As someone else once said ‘Every little helps’ and in the example below the ‘little’ could be in the reduction in lives’ lost:

‘Coating that cools and fights air pollution’ (Sustainia 100 2015, page 34)

Obviously, for all materials there is only limited information at this stage. Solar reflective coatings have been around for a long time, so the heat-reducing aspect of the product is really nothing new, not even at 80% albedo, which I assume is a maximum figure. What appears unique is the ability to remove NOx from the environment. As the major external source is from vehicular traffic. I do have a number of questions/queries

• This appears to be a roof material/coating, most urban situations with high levels of NOx occur are street canyons, so I would expect a general reduction in the background pollutant loading if it was effective, rather than changes at ground level where the pollution is most concentrated and exposure the highest.
• What are the reductions in concentrations of NOx seem in empirical studies from this product?
• Assuming NOx is broken down into ‘harmless’ salts as the article infers, what happens to these? Do they then reduce the reflective capacity of the coating?
• What is the life span of the coating? How long to the reactive components last?

It’s difficult to comment without all the technical data and being able to view the test methods as to how they arrived at their conclusions, however, I think that if this ‘does what it says on the can’ the use of the product could have benefits. Whilst my role is not to endorse any product, especially on the limited information given, I do think it’s worth people looking at this document to see if there are potential solutions to specific problems we face and maybe engaging with these innovators.

Food for thought