Public health implications of smoke and ash concentrations from prescribed burns: A study of open jarrah forests along the Darling escarpment adjacent to the Perth metropolitan area.

DOI: 10.5176/2251-3833_GHC18.106

Authors: Dr John Edwards, Dr Jacques Oosthuizen, Dr Sue Reed

Abstract: Smoke and ash are not homogenous products as they are a solid residue of combustion and contain a complex mixture of chemical products. The ash content varies dependent on its source, but it usually comprises particles of carbon or soot and trace elements. The acute health effects of exposure are not limited to symptoms affecting the eyes, throat and lungs. They can contribute to asthma and cardiopulmonary chronic disease rates and can also contribute to increased risk of some cancers. Smoke and ash presents public health risk to people and communities, through direct and indirect ingestion, inhalation and absorption. The purpose of this study was to look at the public health implications through the identification of ash components at its source and to reduce the confounding effects from other origins. The study investigated the concentration of various chemicals materials from prescribed burns in the Darling Escarpment, adjacent to Perth’s metropolitan area. The relationship between smoke and ash was explored to determine whether concentrations of a range of particulate of sizes (TSP, PM10, PM2.5,) and metals that occur as a result of smoke generated during prescribed burns. Thus establishing a relationship between the concentrations of the air pollutants studied and potential adverse human health effects. 7th Annual Global Healthcare Conference (GHC 2018) Copyright © 2018 ISSN 2251-3833 doi: 10.5176/2251-3833_GHC18.106 It was demonstrated that the smoke concentration from the prescribed burn exceeded Department of Health, Western Australia guidelines of 300 µg/m3. The level of metal present within the ash samples did not exceed health investigation levels and were unlikely to pose a potential risk if left in-situ. However, the metal concentrations in the smoke could not be established while the metals in the ash have the potential of pose a risk if disturbed or mobilised by wind or water. The findings from this study contribute to the management of prescribed burns by providing a better understanding of the composition of smoke and ash and the effects of potential distribution via aerial deposition or runoff.

Keywords: Smoke, Ash, Prescribed Burn, Heavy metal.