Chemistry of emissions at lava-urban interfaces

2024年1月14日，冰岛雷克雅内斯半岛爆发的熔岩流开始焚烧城市建筑。已知火山排放物和城市火灾分别含有许多对健康有害的化合物。虽然这些不同的端元组成是众所周知的，熔岩-城市界面（LUI）的排放还没有研究。关键假设：由于火山和人造化合物的结合，LUI排放物具有独特的化学性质。这种相互作用影响了燃烧过程、排放到环境中的排放物的组成以及大气羽流中的化学反应途径。LUI相互作用也可能改变了熔岩中的脱气过程和岩浆挥发物的释放。由于靠近社区，城市界面处的火山喷发比偏远地区的火山喷发导致人类暴露量更高；小型火山喷发会在人口密集地区造成严重的空气污染。熔岩与城市空间的相遇是准周期性的，例如2018年夏威夷的基拉韦厄火山，2021年坎布尔别哈，拉帕尔马，以及现在冰岛的雷克雅内斯（2024年至今）。尽管认识到表征空气污染源化学性质的重要性，但LUI排放仍未得到研究，这可能是由于具有挑战性的采样条件、不可预测性和每次爆发事件持续时间短的综合原因。在全球范围内，由于建筑扩建到以前无人居住的地区，暴露于LUI排放的人数正在增加。例如，2024年1月在冰岛被熔岩烧毁的房屋是新建的，这些房屋的建造始于火山系统已经处于动荡之中。我们将利用冰岛正在进行的活动作为一个自然实验室，首次在源头和近场（1-40公里距离）对LUI排放化学进行表征。

Lava flows from eruptions on Reykjanes peninsula in Iceland started burning urban structures on 14 January 2024. Volcanic emissions and urban fires, respectively, are known to contain many chemical compounds that are hazardous to health. While these distinct end member compositions are better known, lava-urban interface (LUI) emissions have not been studied. Key hypotheses: LUI emissions have unique chemistry due to the combination of volcanic and human-made compounds. The interaction impacts the combustion process, the composition of the emissions released into the environment, and the chemical reaction pathways in the atmospheric plume. The LUI interaction may also be modifying the degassing processes in the lava, and release of magmatic volatiles.Eruptions at the urban interface lead to higher human exposures than remote eruptions because of their proximity to communities; and small eruptions can cause severe air pollution in populated areas. Lava encounters urban space quasi-periodically, for example Kilauea, Hawaii 2018, Cumbre Vieja, La Palma 2021 and now on Reykjanes, Iceland (2024 - present). Despite the recognition of the importance of characterising chemistry of air pollution sources, LUI emissions remain unstudied, likely due to a combination of challenging sampling conditions, and the unpredictability and the short duration of each eruptive episode. Globally, the number of people exposed to LUI emissions is growing because of building expansion into previously uninhabited areas. For instance, the homes burned by lava in Iceland in January 2024 were newbuilds, the construction of which began when the volcanic system was already in unrest. We will use the ongoing activity in Iceland as a natural laboratory for the first ever characterisation of LUI emission chemistry at-source and in the near-field (1-40 km distance).