Wildland fire ash and particulate distribution in adjacent residential areas

Abstract

In recent decades, the frequency of wildland fire incidents near residential areas has decreased but the number of acres burned has increased, in large part due to changes in forest management methods and further human encroachment in forested regions. There is much debate about whether the wood ash generated by these wildfires can significantly affect residential buildings outside the fire zone perimeter. This study investigates the distribution of ash, soot and char that are generated from wildfires and migrate into adjacent residential regions. For this purpose, a wildland fire in Bastrop, Texas, was studied with samples collected from a variety of locations within the fire site and in adjacent areas. The collected samples were assayed for pH, asbestos, heavy metals and polynuclear aromatic hydrocarbons. The results of this investigation showed that the magnitude of the deposition on residential buildings near wildfires is dependent on a variety of variables, in particular the distance from the centre of the fire.