Department of Sciences, University of Roma Tre, Viale G. Marconi 446, 00146 Rome, Italy.
Department of Sciences, University of Roma Tre, Viale G. Marconi 446, 00146 Rome, Italy.
Environ Int. 2024 May;187:108707. doi: 10.1016/j.envint.2024.108707. Epub 2024 Apr 26.
Currently, natural and urban ecosystems are affected by different types of atmospheric deposition, which can compromise the balance of the environment. Plastic pollution represents one of the major threats for biota, including lichens. Epiphytic lichens have value as bioindicators of environmental pollution, climate change, and anthropic impacts. In this study, we aim to investigate the lichen bioaccumulation of airborne microplastics along an anthropogenic pollution gradient. We sampled lichens from the Genera Cladonia and Xanthoria to highlight the effectiveness of lichens as tools for passive biomonitoring of microplastics. We chose three sites, a "natural site" in Altipiani di Arcinazzo, a "protected site" in Castelporziano Presidential estate and an "urban site" in the centre of Rome. Overall, we sampled 90 lichens, observed for external plastic entrapment, melt in oxygen peroxide and analysed for plastic entrapment. To validate the method, we calculated recovery rates of microplastics in lichen. Particularly, 253 MPs particles were detected across the 90 lichen samples: 97 % were fibers, and 3 % were fragments. A gradient in the number of microplastic fibers across the sites emerged, with increasing accumulation of microplastics from the natural site (n = 58) to the urban site (n = 116), with a direct relationship between the length and abundance of airborne microplastic fibers. Moreover, we detected the first evidences of airborne mesoplastics entrapped by lichens. On average, the natural site experienced the shortest fibre length and the centre of Rome the longest. No differences in microplastics accumulation emerged from the two genera. Our results indicated that lichens can effectively be used for passive biomonitoring of microplastic deposition. In this scenario, the role of lichens in entrapping microplastics and protecting pristine areas must be investigated. Furthermore, considering the impact that airborne microplastics can have on human health and the effectiveness of lichens as airborne microplastic bioindicators, their use is encouraged.
目前，自然和城市生态系统都受到不同类型的大气沉积的影响，这可能会破坏环境的平衡。塑料污染是生物群的主要威胁之一，包括地衣。附生地衣具有作为环境污染、气候变化和人为影响生物标志物的价值。在这项研究中，我们旨在调查沿人为污染梯度的空气中微塑料的地衣生物积累。我们从 Cladonia 和 Xanthoria 属中采样地衣，以突出地衣作为被动监测微塑料的工具的有效性。我们选择了三个地点，一个是阿尔蒂帕尼诺的自然地点，一个是 Castelporziano 总统庄园的保护区，一个是罗马市中心的城市地点。总体而言，我们对 90 种地衣进行了采样，观察了外部塑料的捕获、过氧化氧中的熔融和塑料的捕获分析。为了验证该方法，我们计算了地衣中微塑料的回收率。特别地，在 90 种地衣样本中检测到 253 个 MPs 颗粒：97%是纤维，3%是碎片。在这些地点中，微塑料纤维的数量出现了梯度，从自然地点（n=58）到城市地点（n=116），微塑料的积累不断增加，空气中微塑料纤维的长度和丰度之间存在直接关系。此外，我们还检测到地衣捕获的空气中中塑料的第一批证据。平均而言，自然地点的纤维长度最短，罗马市中心的纤维长度最长。两种地衣属之间的微塑料积累没有差异。我们的研究结果表明，地衣可以有效地用于监测微塑料沉积的被动生物监测。在这种情况下，必须研究地衣在捕获微塑料和保护原始区域方面的作用。此外，考虑到空气中微塑料对人类健康的影响以及地衣作为空气中微塑料生物标志物的有效性，鼓励使用地衣。
