Diatomological Distribution of Pearl River in Guangzhou and Yangtze River in Hubei Province and Its Application to the Diagnosis of Drowning Cases

Diatoms have received much popularity as forensic evidence for diagnosing death by drowning. Distribution of diatoms in any water body, and its correlation with the diatom genus recovered from the drowned body can be a method of choice to resolve questions related to drowning sites. In this study, we collected 24 water samples from sites across the Pearl River in Guangzhou and 16 water samples from Yangtze River flowing through Hubei Province, China to do an analysis of diatoms´ distribution and to analyze the relationship between diatom assemblages and drowning sites. The diatoms in the lungs and organs of the circulatory system from 5 postmortem cases died by drowning, which could be observed from the macroscopic autopsy findings and police reports, were compared with diatomological distribution mapping choosing diagnosis parameters including diatom genus, size, concentration, etc. The analysis was undertaken in order to record the significant variation in diatom diversity in the 6 (selected) different types of water bodies in Guangzhou (China) during different seasons (summer, winter), Yangtze river in Hubei Province in summer. Data of Pearl Rive in Guangzhou obtained have been utilized to create diatomological distribution maps, which can diagnosis the suspected drowning cases occurring in a particular area and characterization of different water bodies.