An Italian cement company has developed a treatment for building materials that transforms pollutants into less harmful substances, such as water and carbon dioxide. Experts suggest that covering 15 percent of a smog-choked industrial city like Milan could reduce pollution by 50 percent.
The results so far are astonishing: A street in the town of Segrate, near Milan, with an average traffic of 1,000 cars per hour, has been repaved with the compound, “and we have measured a reduction in nitric oxides of around 60%,” says Italcementi’s spokesperson Alberto Ghisalberti. In a test over an 8,000 square meter (or approximately 2 acres) industrial area paved with active blocks near Bergamo, Italcementi’s hometown, the reduction was measured at 45%.
In large cities such as Milan, with persistent pollution problems caused by car emissions, smoke from heating systems, and industrial activities, both the company and outside experts estimate that covering 15% of all visible urban surfaces (painting the walls, repaving the roads) with products containing TX Active could abate pollution by up to 50%, depending on the specific atmospheric conditions.
Of course, this approach isn’t meant to replace efforts to curb pollution, but it can significantly magnify their effects. Here’s how it works: The active principle—basically a blend of titanium dioxide that acts as photocatalyzer—can be incorporated in cement, mortar, paints, and plaster.
In the presence of natural or artificial light (this applies also indoors) the photocatalyzer significantly speeds up the natural oxidation processes that cause the decomposition of pollutants, transforming them into less harmful compounds such as water, nitrates, or carbon dioxide.