[Diatom test in lung tissue of corpses in water and causes of death].

OBJECTIVE:To explore potential application of diatom test of lung tissue in investigation of cause of death in victim found in the water. METHODS:Four hundred and seven cases were collected and analyzed for cause of death and the nature of case. Diatom test was performed in tissues and the amount was quantified. Forty-five rabbits died in the water (antemortem, postmortem and different seasons drowning) were randomly divided into 9 groups and the diatom content in lung tissue were tested with the method of nitric acid. RESULTS:In 407 drowning cases, 372 cases showed a positive result of diatom test. In positive cases, the amount of accidents or suicide were 35 and homicide were 21. Thirty-five cases showed negative result of diatom test and majority were homicide in which bodies were thrown into the water after killing. Some drowning cases were in special circumstances. Animal experiments confirmed that a large amount of diatoms in lung tissue were detected in drowning victim and showed the same type in water. The amount of diatom in lung tissue was usually lower in the summer and winter comparing with spring and autumn. CONCLUSION:The diatom test could be considered as an auxiliary evidence in determination of cause of death in body found in the water. The test results were related with manner of death. The nature of case should be synthetically determined based on autopsy, criminal scene and details of the cases, etc.