Diatom analysis of bone marrow is used in forensic drowning investigations. The rationale for sampling bone marrow rather than lung tissue is:

• A Diatoms cannot penetrate lung alveoli and are only found systemically
• B Bone marrow diatoms are always endogenous and independent of water exposure
• C In putrefied bodies where lung tissue is destroyed, diatoms persist in bone marrow; their detection proves ante-mortem inhalation of water (drowning during life) rather than post-mortem submersion ✓
• D Bone marrow diatom analysis is only useful in salt-water drowning cases

Explanation

When a living person drowns, inhaled water crosses the alveolar-capillary membrane carrying diatoms into the circulation; these siliceous microorganisms (resistant to putrefaction and acids) are then deposited systemically in kidneys, liver, bone marrow, and brain. Finding diatoms in bone marrow (or other distant organs) in the same concentration and species as in the drowning medium proves antemortem water aspiration, distinguishing true drowning from postmortem immersion of a corpse. In advanced decomposition, lung tissue is unavailable, making bone marrow the specimen of choice. This test has limitations if the water source contains few diatoms.

Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.

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Written and medically reviewed by the StethoPrep medical team.