Dutch concrete cleans the air — just the air

A study in the small Dutch town of Hengelo is conducting field research by the University of Twente to determine if a new type of concrete can reduce acid rain. Concrete paving stones are laced with photosensitive titanium dioxide. When used to pave highways, the additive reacts with sunlight and the nitrogen oxide particles emitted by car exhaust, thereby forming nitrates.

The testing is being conducted by measuring the air quality surrounding a treated section of the highway and comparing the results from an untreated portion. According to a statement issued by the University:

With one rain shower everything is washed clean… By measuring the air quality in both areas, we will be able to show the efficacy of the bricks.

I won’t pretend to be an expert on nitrates, or the amount needed to determine toxicity, but if the nitrates are getting “washed clean”, then they still have to go somewhere. Presumably, they are going to end up in a larger source of water. Be it ground water or out-to-sea, nitrates are still toxic to marine life and sensitive humans.

It sounds too much like cleaning up one problem with another – or worse yet, cleaning it up and letting it drain into someone else’s back yard. This just doesn’t ring with that problem-solving chime I want to hear.