Dutch scientists say their revolutionary concrete can cut urban air pollution by 45 percent. Eindhoven University of Technology scientists have installed air-purifying cement onto a city block in Hengelo, Netherlands, and published the results, which found that it reduced nitrogen oxide air pollution up to 45 percent in ideal weather conditions. This is an average reduction of 19 percent each day. The concrete, dubbed "photocatalytic," is made with cement sprayed with a chemical, titanium oxide, that neutralizes air pollutants, the researchers’ abstract states.