Dust kicked up by vehicles traveling on roads may make up 33% of air pollution. Road dust consists of deposits of vehicle and industrial exhaust gas, particles from tire and brake wear, dust from paved roads or potholes, and dust from construction sites. Road dust is a significant contributor to the generation and release of particulates into the atmosphere. Control of road dust is a significant challenge in urban areas, and also in other locations with high levels of vehicular traffic upon unsealed roads, such as mines and landfills.