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Published on: November 1, 2016
Human body buoyancy: a study of 98 men
Journal of Forensic Sciences
|July 1, 1977
Summary
Drowning victims may sink or float depending on lung volume and water salinity. Even at near-death lung capacity, most bodies float in seawater, while few float in freshwater, indicating buoyancy is not a definitive cause of death indicator.
Area of Science:
- Forensic Science
- Human Physiology
- Oceanography
Background:
- Determining the cause of death for submerged bodies is challenging.
- Body buoyancy is influenced by lung volume and water salinity.
- Previous research has not conclusively linked buoyancy to drowning versus other causes of death.
Purpose of the Study:
- To investigate the buoyancy of human bodies at various lung volumes in freshwater and seawater.
- To assess the reliability of body buoyancy as an indicator of drowning.
- To provide data for forensic investigations involving submerged bodies.
Main Methods:
- Calculated specific gravity and buoyancy for 98 men.
- Measured buoyancy at different lung volumes, including total lung capacity and functional residual capacity.
- Simulated freshwater and seawater conditions.
Main Results:
- All subjects could float at total lung capacity in both freshwater and seawater.
- At functional residual capacity (approximating a recently deceased body's lung volume), 69% floated in seawater, but only 7% in freshwater.
- Buoyancy varies significantly with lung volume and water salinity.
Conclusions:
- Drowned bodies are statistically more likely to sink than bodies deceased from other causes.
- Body buoyancy alone is insufficient to determine the cause of death.
- Lung volume and water salinity are critical factors in body buoyancy after death.
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