Environmentally persistent free radicals are ubiquitous in wildfire charcoals and remain stable for years
Environmentally persistent free radicals are ubiquitous in wildfire charcoals and remain stable for years
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DOI：
10.1038/s43247-021-00138-2
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发表时间：
2021-03
影响因子：
7.9
通讯作者：
G. Sigmund;C. Santín;Marc Pignitter;Nathalie Tepe;S. Doerr;T. Hofmann
中科院分区：
文献类型：
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作者：
G. Sigmund;C. Santín;Marc Pignitter;Nathalie Tepe;S. Doerr;T. Hofmann
全球景观火灾每年产生约 256 Tg 的热解碳或木炭。木炭作为环境持久性自由基（潜在有害活性氧物质的前体）来源的作用很少受到限制。在这里，我们分析了从 10 场野火中收集的 60 个木炭样本，其中包括跨越不同寒带、温带、亚热带和热带气候的森林、灌木丛和草原的树冠和地表火灾。使用电子自旋共振光谱，我们测量了木炭样品中高浓度的环境持久性自由基，远高于土壤中发现的自由基。浓度随着碳化程度的增加而增加，木质燃料有利于更高的浓度。此外，环境持久性自由基在出人意料的至少5年的时间内保持稳定。我们认为野火木炭是全球环境持久性自由基的重要来源，因此也可能是有害活性氧的重要来源。
Globally landscape fires produce about 256 Tg of pyrogenic carbon or charcoal each year. The role of charcoal as a source of environmentally persistent free radicals, which are precursors of potentially harmful reactive oxygen species, is poorly constrained. Here, we analyse 60 charcoal samples collected from 10 wildfires, that include crown as well as surface fires in forest, shrubland and grassland spanning different boreal, temperate, subtropical and tropical climate. Using electron spin resonance spectroscopy, we measure high concentrations of environmentally persistent free radicals in charcoal samples, much higher than those found in soils. Concentrations increased with degree of carbonization and woody fuels favoured higher concentrations. Moreover, environmentally persistent free radicals remained stable for an unexpectedly long time of at least 5 years. We suggest that wildfire charcoal is an important global source of environmentally persistent free radicals, and therefore potentially of harmful reactive oxygen species.