Post-Mortem Immersion
Definition
Placement of a body in water after death. Passive water entry into the upper airways and body cavities can carry diatoms into the trachea and proximal bronchi but does not produce hematogenous spread to bone marrow and remote organs, which is the key distinction the test exploits.
- Definition
- Body placed in water after death has already occurred
- Diatom pathway
- Passive entry into upper airways and body cavities
- Key limit
- No hematogenous spread to bone marrow or remote organs
- Relevance
- The distinction the diatom drowning test relies on
Common questions
Why does the absence of marrow diatoms matter for distinguishing this from true drowning?+
In life, active breathing during drowning drives diatoms deep into alveoli where they cross into the bloodstream and reach distant organs and marrow. A body immersed only after death cannot do this because circulation and breathing have already stopped, so diatoms stay confined to the airway and cavities rather than reaching remote sites.
Does post-mortem immersion always leave zero diatoms in the lungs?+
No. Passive water movement can still carry diatoms into the trachea and proximal bronchi, which is why a positive lung finding alone is not proof of drowning; the marrow and remote-organ result is what the test relies on to separate the two scenarios.
Related terms
- Acid Digestion
- A laboratory preparation step in which concentrated mineral acids are used to destroy all organic tissue in a sample, leaving only acid-resistant...
- Ante-Mortem Drowning
- Drowning that occurs while the victim is still alive and the cardiopulmonary system is functioning. Active breathing and circulation are prerequisites for...
- Bone Marrow
- The fatty and haematopoietic tissue inside long bones such as the femur and tibia. Because it is enclosed in dense cortical bone,...
- Control Sample
- A water sample collected from the suspected drowning environment at or shortly after the time of body recovery. Its diatom assemblage is...
- Hematogenous Dissemination
- Spread of a substance via the bloodstream. In the diatom test, diatoms aspirated into the lungs during ante-mortem drowning enter pulmonary capillaries...