In this work, we performed a palynological analysis of soil sampled from the footwear in order to provide their spatial and temporal classification. The sampling was performed in the shoes of 20 volunteers, in two different periods: autumn–winter and spring 2016/2017. The volunteers belonged to the same geographic region within a radius of 500 m. During the laboratorial treatment, the pollinic content present in the shoes sole was concentrated applying several treatments to destroy the exogenous material. A hierarchical cluster analysis was performed to verify whether it was possible to distinguish the samples based on their pollen assemblages. All the samples showed pollinic content, even when the shoes were apparently clean. The pollen types found were similar across the sampling period although with different pollen assemblages. In the winter samples, there was a prevalence of Fraxinus , Myrtaceae, Pinaceae (mostly Cedrus ) and Poaceae pollen, while in the spring pollen of Olea , Poaceae, Pinaceae (namely Pinus ) and Quercus was observed. Our results also demonstrated the discrimination between close sites (approximately 200 m), showing that the use of palynological analysis in footwear allows the collection of temporal and spatial information that can be used in forensic investigations.

中文翻译：

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法医背景下葡萄牙西北部巴塞洛斯地区所穿鞋类的时空环境花粉分析

在这项工作中，我们对从鞋类中取样的土壤进行了孢粉学分析，以提供它们的空间和时间分类。采样是在 20 名志愿者的鞋子中进行的，在两个不同的时期：2016/2017 年秋冬季和春季。志愿者在 500 m 半径范围内属于同一地理区域。在实验室处理期间，鞋底中存在的花粉含量被浓缩，应用多种处理来破坏外源性物质。进行层次聚类分析以验证是否可以根据其花粉组合区分样品。所有样品都显示出花粉含量，即使鞋子显然是干净的。尽管花粉组合不同，但在整个采样期间发现的花粉类型相似。在冬季样品中，白蜡、桃金娘科、松科（主要是雪松）和禾本科花粉流行；而在春季花粉中，油橄榄、禾本科、松科（即松）和栎属的花粉普遍存在。我们的结果还证明了近距离站点（约 200 m）之间的区别，表明在鞋类中使用孢粉学分析可以收集可用于法医调查的时间和空间信息。