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Updated: Jan 15, 2026
Author Spotlight: Diatom Testing for Forensic Drowning Examination
Published on: November 10, 2023
Diatom testing for closed organs should be carefully performed and interpreted: the effect of post-mortem change and
Shigeki Tsuneya1, Makoto Nakajima1, Yukiko Uemura1
1Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Introduction:
Diatoms inhaled with a drowning medium are thought to reach closed organs, including the kidney and liver, through circulation; however, this is uncertain. Thus, to assess this doubt, we evaluated the relationship between resuscitation or decomposition and diatom concentration in closed organs (kidney and liver) (Cc).
Materials And Methods:
We retrospectively reviewed our diatom test results in 62 natural water- and five bathtub-water drowning consecutive forensic autopsies. Tukey's honestly significant difference (HSD) test and multiple regression analysis were performed in natural water-drowning cases, to evaluate the relationship between Cc and three groups of post-mortem changes (PC): no or little, moderate, or severe PC. Furthermore, Welch's t-test and multiple regression analyses were performed for natural water cases with no or little PC, to examine the effect of resuscitation on Cc. The Cc in natural and bathtub cases were compared using Welch's t-test.
Results:
Severe PC significantly increased the Cc in both analyses. Resuscitation caused no significant changes in Cc in either analysis. Natural water-drowning did not increase Cc compared with bathtub-drowning.
Conclusion:
Our results suggest a post-mortem increase in Cc and diatom detection in non-drowning cases owing to natural load or laboratory contamination. Thus, the probability of Cc increasing during drowning or resuscitation was very low, Therefore, diatom testing of closed-organ samples should be carefully performed, and the results should be interpreted cautiously, especially in cases with severe post-mortem changes.
