The Charleston County Department of Public Works is testing a photocatalytic material that contains titanium dioxide on freshly asphalted streets to cool down roads which is aimed to reduce the urban heat island effect. The material is also being tested to see if the road will last longer and accelerate the decomposition of toxins in vehicle exhaust. It's a mix of titanium dioxide and Reclamite. Reclamite is currently being used as a pavement preservation treatment to increase the life of roads by about three years with each treatment.
The streets will stay cooler because they are reflecting more light and also will have lower toxic output by absorbing nitrogen oxides that contribute to smog and rain. The asphalt treatment was applied in the Rosemont neighborhood, Union Heights, and a strip on Bennett St. near MUSC.
Urban heat islands occur when urban areas replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorbs and retain heat. This effect increases energy costs, air pollution levels, and heat-related illness and mortality.
Trees and other plants help cool the environment, making vegetation a simple and effective way to reduce urban heat island. Trees and vegetation lower surface and air temperatures by providing shade through evapotranspiration. Shaded surfaces can be between 20-45º F cooler than the peak temperatures of unshaded surfaces.