Maastricht University, Maastricht, The Netherlands.
Department of Medical Biology, Section Anatomy, Amsterdam University Medical Centre, Location Academic Medical Centre, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands.
Int J Legal Med. 2021 May;135(3):1025-1034. doi: 10.1007/s00414-020-02455-1. Epub 2020 Nov 19.
Bone has photoluminescent characteristics that can aid the analysis of thermally altered human skeletal remains as part of the forensic anthropological investigation. Photoluminescence stands collectively for fluorescence and phosphorescence. Because the difference in lifetime between fluorescence and phosphorescence is usually in the range of nano- to microseconds, it is only possible to visually determine whether bone phosphoresces when the lifetime is long enough to be observed. For this study, a distinction was made between long-decay and short-decay phosphorescence. So far, it was unknown whether (thermally altered) human bone emits long-decay phosphorescence after being illuminated and, thus, whether phosphorescence contributes to the observed photoluminescence. If so, whether the observable phosphorescence is dependent on temperature, exposure duration, surrounding medium, bone type, skeletal element, and excitation light and could aid the temperature estimation of heated bone fragments. In this study, bone samples were subjected to heat in the range of from room temperature to 900 °C for various durations in either air or adipose as surrounding medium. In addition, different skeletal elements of a human cadaver were recollected after cremation in a crematorium. Both sample collections were illuminated with light of different bandwidths and visually inspected for phosphorescence and photoluminescence. The samples were scored by means of a scoring index for the intensity of long-decay phosphorescence and photographically documented. The results show that thermally altered human bone fragments do phosphoresce. The observed phosphorescence is more dependent on temperature than on exposure duration, surrounding medium or skeletal element. Of the used wavelength bands, ultraviolet light provided the most temperature-related information, showing changes in both phosphorescence intensity and emission spectrum. Long-decay phosphorescence and fluorescence with short-decay phosphorescence coincide; however, there are also temperature-dependent differences. It is therefore concluded that phosphorescence contributes to the observable photoluminescence and that the visibly observable phosphorescent characteristics can aid the temperature estimation of cremated human skeletal fragments.
骨骼具有磷光特性，可以帮助分析作为法医人类学调查一部分的受热改变的人类骨骼遗骸。磷光集体代表荧光和磷光。由于荧光和磷光之间的寿命差异通常在纳秒到微秒的范围内，因此只有当寿命足够长以便观察时，才能通过肉眼确定骨骼是否发出磷光。在这项研究中，区分了长衰减和短衰减磷光。到目前为止，还不知道（受热改变的）人类骨骼在被照射后是否发出长衰减磷光，以及磷光是否有助于观察到的磷光。如果是这样，那么可观察到的磷光是否取决于温度、暴露时间、周围介质、骨骼类型、骨骼元素以及激发光，并有助于加热的骨骼碎片的温度估计。在这项研究中，将骨骼样本在空气或脂肪作为周围介质的不同温度范围内加热不同的时间，从室温到 900°C。此外，还从火葬场中重新收集了火化后的人类尸体的不同骨骼元素。两种样本收集都用不同带宽的光照射，并对磷光和磷光进行了目视检查。使用长衰减磷光强度的评分指数对样本进行评分，并拍照记录。结果表明，受热改变的人类骨碎片确实会发出磷光。观察到的磷光更多地取决于温度，而不是暴露时间、周围介质或骨骼元素。在所使用的波长带中，紫外线提供了与温度最相关的信息，显示出磷光强度和发射光谱的变化。长衰减磷光和短衰减磷光的荧光同时存在；然而，也存在与温度相关的差异。因此，可以得出结论，磷光有助于观察到的磷光，并且可观察到的磷光特性可以帮助估计火化的人类骨骼碎片的温度。
