Contribution to understanding the influence of fires on the mercury cycle: Systematic review, dynamic modelling and application to sustainable hypothetical scenarios

Abstract

Mercury (Hg) mobilization and accumulation in the environment is directly related to forest fires. Biomass burning accounts for about 13% of the total contribution of Hg from natural sources. The aim of this work is to contribute to the knowledge of how wildfires modify mercury compounds behaviour and the effects it has in the Hg cycle, based on a systematic bibliographic review and analysis. Systems dynamics is an adequate focus to analyze the mobilization of Hg due to wildfires, which meets all the requirements to be studied by multimedia modelling. The development and application for the first time of a dynamic multimedia model of Hg taking into account specifically the influences of wildfires is one of the novelties of this work. Different scenarios show that an increase in the number of fires will consequently increase the mercury emitted into the atmosphere, modifying its natural cycle, producing a long-term modification of Hg compositions and concentrations in the different media. Hg movement caused by wildfires can cause complications in living beings and alter the ecosystems. This study found that the Hg soil content could as well be an indicator to measure the impact of fire on the environment. This model can also be generalized to conduct additional studies under comparable conditions, helping to understand the importance of forest fires in global Hg cycles. Graphical abstract

Towards the Sustainable Exploitation of Salt-Tolerant Plants: Nutritional Characterisation, Phenolics Composition, and Potential Contaminants Analysis of Salicornia ramosissima and Sarcocornia perennis alpini

“…In this context, it is furthermore important to note that the Mondego estuary is considered a less polluted estuary, due to the limited industrialisation of the area [ 83 , 84 ]. However, with climate change, phenomena such as forest fires have intensified dramatically in Portugal, and a direct relationship has been documented between the mobilisation and accumulation of elements such as Hg, Mn, and Zn in ecosystems and the occurrence of these events [ 84 , 85 ], which could ultimately lead to a greater accumulation of these HMs in the species under study. Finally, as shown in the studies by Yang et al [ 86 ] and Sanjosé et al [ 72 ], in the case of specimens from highly contaminated areas, the risk of accumulation by HMs at levels that represent a health risk is real and should not be overlooked.…”

Temperature Thresholds of Pyrogenic Dissolved Organic Matter in Heating Experiments Simulating Forest Fires

“…This phenomenon may result from the transformation of polyphenolics into polyaromatic compounds at high heating temperatures . Compared to polyphenolics-rich humic acids or nonpyrogenic DOM, dissolved condensed aromatics have stronger binding affinities for organic pollutants (e.g., polycyclic aromatic hydrocarbons) and metals (e.g., Hg) and stronger chlorine reactivity toward forming toxic nitrogenous disinfection byproducts during water supply. , Therefore, high-temperature wildfires may impact environmental quality more severely than low-temperature wildfires or prescribed burns by increasing organic pollutants, metals, and nitrogenous disinfection byproduct precursors in downstream water bodies. This study proposes the use of TT max and TT 0 to explore the formation and production of pyrogenic DOM components to advance the mechanistic understanding of wildfire impacts on biogeochemistry processes.…”

Mercury abatement in the environment: Insights from industrial emissions and fates in the environment

“…Warmer temperatures in the Arctic degrade the permafrost, releasing MeHg, which translocates to the Arctic sediments and soils [ 150 ]. Since biomass burning contributes to 13% of the total natural Hg emissions, the expected increase in the intensity of wildfires will significantly increase legacy Hg emissions [ 151 ].…”