emissions have increased in recent years that's because there are more and more diesel powered vehicles when diesel fuel is burned nitrogen and oxygen from the air injected into the engine combine to form measures in dioxide it's toxic and has been linked to cancer but there may be a way to get rid of it. get my from where working with industry and other research institutes to develop a material that could be added to asphalt road surfaces. the material the scientists are working with is called titanium dioxide in the form of a white powder it would be mixed with the asphalt when a road is built or resurfaced. it's an idea that's already being explored in the construction industry the german company stay out of power minerals has developed a method for mixing titanium dioxide with concrete. the company has produced paving slabs which it says can literally purify the air in what it hopes will be