Smog-Eating Streets Could Clean the Cities of Tomorrow 

When people imagine cities, their first thought may be of the urban skyline and a mosaic of lights, but for many, the picture is a bit less romantic: a cloud of smog. But a team of scientists from the Netherlands hope their research on pollution-eating pavement may one day change that.

What the Eindhoven University of Technology team has done is to install a concrete paving of titanium dioxide, or photocatalytic pavement, on a city block in Hengelo, Netherlands. The material is known for its ability to strip pollutants from the air and break them into harmful parts, but never before has it been integrated into a road—the staple of an urban society.

For comparison, another part of the street was paved with normal blocks. The researchers then set out to measure the levels of nitrogen oxide (NOx), poisonous gases emitted from cars that interact with other atmospheric compounds to create smog.

One year later, the team found that on average, the air pollution measured over the treated street was reduced by 19 percent when compared to the control. But when looked at specifically in the afternoons, that figure jumped to 28 percent. And in ideal weather conditions (a sunny day with low humidity) it soared to 45 percent.

David Brown, chief executive of the Institution of Chemical Engineers, explains that the time for research in this area is now. “In recent weeks we have seen the difficulties smog can cause in cities like Singapore,” says Brown.

”Preventing air pollution is clearly important to our long-term health and environmental protection, but 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,” he continued.

While Brown believes that further studies are needed to refine the photocatalytic materials, particularly across various environments, he says that the potential is there.

If Brown has his way, the same cities that produce pollution will actually be responsible for cleaning it up as well.