Controlled burn and immediate mobilization of potentially toxic elements in soil, from a legacy mine site in Central Victoria, Australia Joji Abraham ⁎, Kim Dowling, Singarayer Florentine School of Applied and Biomedical Sciences, Faculty of Science and Technology, Federation University Australia, Mount Helen Campus, VIC 3353, Australia HIGHLIGHTS • Legacy gold mining sites have elevated potentially toxic element (PTE) concen- trations. • PTEs are sequestered in the soil organic matter and vegetation, limiting its mo- bility. • Controlled burns remobilized PTEs such as Zn, Mn, Cd & Hg. • Liberated PTE mobilized to soil, and may be to air & water environment. • Controlled burns should be carefully considered as a forest management strategy. GRAPHICAL ABSTRACT abstract article info Article history: Received 27 July 2017 Received in revised form 21 October 2017 Accepted 21 October 2017 Available online 6 November 2017 Editor: D. Barcelo Conducting controlled burns in fire prone areas is an efficient and economic method for forest management, and provides relief from the incidence of high severity wild fires and the consequent damage to human property and ecosystems. However, similar to wild fires, controlled burns also affect many of the physical and biogeochemical properties of the forest soil and may facilitate remobilization of potentially toxic elements (PTEs) sequestered in vegetation and soil organic matter. The objective of the current study is to investigate the mobilization of PTEs, in Central Victorian forest soils in Australia after a controlled burn. Surface soil samples were collected two days be- fore and after the controlled burn to determine the concentration of PTEs and to examine the physicochemical properties. Results show that As, Cd, Mn, Ni and Zn concentrations increased 1.1, 1.6, 1.7, 1.1 and 1.9 times respec- tively in the post-burn environment, whereas the concentrations of Hg, Cr and Pb decreased to 0.7, 0.9 and 0.9 times respectively, highlighting considerable PTE mobility during and after a controlled burn. Whilst these results do not identify very strong correlations between physicochemical properties of soil and PTEs in the pre- and post- burn environments, PTEs themselves demonstrated very strong and significant correlations. The mobilization of As, Hg and other toxic elements raise potential health concerns as the number of controlled burns are projected to increase in response to climate change. Due to this increased level of PTE release and remobilization, the use of any kinds of controlled burn must be carefully considered before being used as a forest management strategy in mining-affected landscapes which include areas with high PTE concentrations. © 2017 Elsevier B.V. All rights reserved. Keywords: Arsenic and metals Environmental pollution Forest fire Historical mining Prescribed fire Soil and water pollution 1. Introduction Potentially toxic elements (PTEs) such as As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn, contribute to contamination in soil and aquatic Science of the Total Environment 616–617 (2018) 1022–1034 ⁎ Corresponding author. E-mail address: J.abraham@federation.edu.au (J. Abraham). https://doi.org/10.1016/j.scitotenv.2017.10.216 0048-9697/© 2017 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv