Fugitive dust and particulate matter (PM) emissions are a concern when processing material such as sand, gravel, fly ash and cement. Fugitive dust is solid matter emitted from any non-combustion source. Particulate Matter refers to small solid and liquid particles such as dust, sand salt spray, metallic and mineral particles, pollen, smoke, mist and acid fumes. PM10 refers to the fraction of particulate matter with an aerodynamic diameter of 10 micrometers and smaller. These particles are small enough to penetrate the lower respiratory tract and can be considered a health hazard.