Department of Environmental Geosciences, University of Vienna, Althanstraße 14 (UZA II), 1090 Vienna, Austria.
Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
J Hazard Mater. 2022 Jun 5;431:128068. doi: 10.1016/j.jhazmat.2021.128068. Epub 2021 Dec 11.
Chrysotile asbestos is a toxic and carcinogenic mineral that has been used in a variety of industrial and consumer applications. Much of the fiber- and cement-containing asbestos waste has ended up in terrestrial environments. Chrysotile weathering in soils and the potential for natural attenuation have, however, hardly been examined yet. Here we explored how soil properties influence the dissolution rate of chrysotile, the release of the carcinogenic metals chromium and nickel, and the hydroxyl radical (HO) generation by chrysotile fibers. Chrysotile dissolution rates in soil suspensions decreased with increasing soil-pH and were lower than reported rates in soil-free systems. Dissolved organic carbon did not markedly accelerate dissolution at circumneutral pH, whereas cement mixed with soil inhibited dissolution because of its alkalinity. The HO-yield of incubated fibers in non-amended soils eventually decreased by 60-75%. The decline was fastest in an acidic podzol soil, yet was followed by a small rebound. Cement amendment induced the largest HO-yield reduction (∼90%), presumably due to surface coating of the fibers. Overall, this work demonstrates that the potential for natural attenuation of chrysotile asbestos in soils critically depends on soil chemical parameters and the presence of cement in association with the fibers.
温石棉是一种有毒和致癌的矿物质，曾被广泛应用于各种工业和消费产品。大量含有纤维和水泥的石棉废物最终进入了陆地环境。然而，温石棉在土壤中的风化以及自然衰减的潜力尚未得到充分研究。在这里，我们研究了土壤性质如何影响温石棉的溶解速率、致癌金属铬和镍的释放以及温石棉纤维产生的羟基自由基（HO）。温石棉在土壤悬浮液中的溶解速率随土壤 pH 值的升高而降低，且低于无土壤体系中的报告速率。在近中性 pH 值下，溶解有机碳并没有显著加速溶解，而与土壤混合的水泥由于其碱性抑制了溶解。在未改良的土壤中培养的纤维产生的 HO 产量最终降低了 60-75%。在酸性灰化土中下降最快，但随后出现了小幅度反弹。水泥改良导致 HO 产量降低幅度最大（约 90%），这可能是由于纤维表面的涂层。总的来说，这项工作表明，温石棉石棉在土壤中自然衰减的潜力取决于土壤化学参数以及与纤维共存的水泥的存在。
