Planting more trees, encouraging the use of public transportation and bikes, and developing clean energy; all these are just some of the ways that we’ve been trying to deal with the presence of smog in our cities. Now comes a new innovation: pavements that eat smog.
The headline in The Los Angeles Times on July 5 read “Dutch Scientists Invent Pavement That Eats Smog,” but with just a little digging, I discovered that photocatalytic cement, the smog-eating kind, was in fact developed for the Vaticanáby the leading Italian cement maker Italcementi.
The occasion was the 2,000th anniversary of the Christian faith, and for a date of such significance, the Holy See wanted to create a church that would retain its new appearance despite Rome’s high levels of air pollution.
So that’s where it started.
By using titanium oxide, the company was able to create a material that, when exposed to natural sunlight, triggers a chemical reaction that makes the dirt on the cement’s surface decompose, meaning that it is self-cleaning.
It was only after further research that it was discovered that, in addition to its cleansing properties, the material had pollution reduction abilities capable of cleaning up smog in nearby air by breaking down the nitrogen oxides, the group of poisonous gases produced by cars and power plants that create smog when they react with other compounds in the atmosphere.
The very same pavement is already in use in the US.
In October, 2012, Chicago unveiled the “Greenest Street in America,” a two-mile stretch in the city’s Pilsen neighborhood.
Here’s how Inhabitat described it:
In addition to new pedestrian and bicycle features, the innovative new street surface will filter stormwater, helping to prevent the city’s combined sewers from overflowing. Most impressive of all, the cement used to pave the street cleans the surface of the roadway and removes pollution from the air.
Naturally, this makes the photocatalytic cement a perfect paving material as it successfully reduces the amount of toxins expelled by vehicles and inhaled by pedestrians. Italy and other areas of Europe have already paved many of their roads with the revolutionary material, but Chicago is reportedly the first city in America to adopt it.
So maybe Dutch scientists didn’t invent this new wonder pavement, but researchers at Eindhoven University of Technology have been carrying out some thorough research on the new material. After spraying paving blocks with titanium oxide on one block in the city of Hengelo they left the pavement on an adjacent street untouched so as to act as a control.
In a report published in the Journal of Hazardous Materials, the scientists describe how they took measurements on both streets over the course of a year and found that the photocatalyctic pavement reduced nitrogen oxide air pollution by up to 45% in ideal weather conditions and 19% over the course of a day.
Institution of Chemical Engineers Chief Executive David Brown said in a news release, “This latest research shows the potential of chemically engineered surfaces to further improve our quality of life, especially in major urban areas where traffic emissions are high.”Ł
Whether this will prove cost-effective is another story, but any move toward cleaning up our urban environment is exciting. Now if only we could get people to stop driving their cars so much.
Photo Credit: thinkstock