Diatomological investigation in sphenoid sinus fluid and lung tissue from cases of suspected drowning.

We report on the presence, distribution and numbers of diatoms within specific organs as a result of drowning in fresh, treated and seawater. Specimens of sphenoid sinus fluid and lung tissue from 100 cases of suspected drowning and 20 cases where death was by natural causes, to act as a control, were examined for the presence of diatoms. In the 100 cases where the deceased was suspected to have drowned, 94 were confirmed as a death by drowning after autopsy with the other six being reported as death by another cause. No diatoms were found in cases confirmed as death by causes unrelated to drowning, with the exception of possible contamination via open wounds and through decomposition. In 94 cases, where all fatalities were confirmed as death by drowning, there were 81 cases in which diatoms were detected in samples taken from the sphenoid sinus fluid and/or lung tissue. No, or only few, diatoms were observed from the samples where the deceased drowned in treated waters such as spa or swimming pools. A significantly higher number of diatoms were detected in the sphenoid sinus fluid and lung tissue of confirmed drowning cases in fresh water compared to seawater. More diatoms were observed in sphenoid sinus fluid compared to lung tissue regardless of the water in which the deceased drowned. This study illustrates the potential use of diatom screening using both sphenoid sinus fluid and lung tissue to determine the cause of death in suspected cases of drowning. This report also highlights specific variables that need to be considered prior to such as conclusion being reached.