Water Submersion Postmortem Artifacts

• Goose skin ("goose bumps," cutis anserina). This artifact results from spasm of the erector pilae muscles owing to exposure to cold (see Chapter 2, Heading 2. and ref. 16).

• Wrinkled hands ("washerwoman's hands") and feet (see Fig. 12; Chapter 7, Fig. 31; and ref. 16).

• Conjunctival petechiae can disappear after 4 h of fresh water submersion probably due to hemolysis caused by the hypotonic medium (168).

• Decomposition obscures or mimics signs of drowning (see Chapter 2, Subheading 5.2. and refs. 6, 15, and 17).

Drowning Signs Forensic Medicine
Fig. 12. Wrinkling of soles owing to prolonged water submersion (see Chapter 7, Fig. 31).

° Apparent lung "congestion" (16).

° Extravasation of sanguinous fluid into respiratory tract and pleural cavities (16). ° Gas admixing with decomposition fluid can simulate froth in respiratory tract; sanguinous fluid can be expelled from the nose and mouth (16). ° Dehiscence of incised wounds in varying stages of healing (up to 6 mo) because of bloating (169). ° Signs of drowning disappear (3).

• Head-down position

Because the specific gravity of the head is greater than that of the feet, a submerged body floats in a head-down position.

° Lividity in head and neck area and on anterior surface of body (see Chapter 2, Subheading 3.3. and ref. 6); mastoid/middle ear "hemorrhages" may be a sign of lividity (see Fig. 9; Subheadings 10.6. and 14.3.) ° Artifactual neck hemorrhages (rule out resuscitation; see Fig. 13).

° Lethal injuries can be difficult to interpret (3). ° Prolonged submersion can leach blood from open skin wounds. ° Wildlife, underwater and shore hazards can cause injury (Fig. 14; refs. 2 and 6). ° In shallow water, the head-down position can lead to certain areas of body (face, outer forearms, knees) scraping the bottom (see Heading 9; Fig. 5; and ref. 170). ° Abrasions and contusions of the forehead may be caused by removal from water (e.g., side of pool [11]). ° Resuscitation effects (see Chapter 3, Subheading 2.6. and ref. 2).

• Floating to the surface

A body does not float until its specific gravity reaches a point of buoyancy from gases generated from decomposition. Interestingly, of 104 bodies recovered floating in New York waterways, 28 were not decomposed (5). If a body's specific gravity exceeds that of water (fresh water = 1.000; sea water = 1.026), then it sinks (104). The specific gravity of a body is increased by various means (addition of weights, aspiration

Decomposition Body Sea
Fig. 13. Young male drowning victim recovered from a swimming pool. Resuscitation. Posterior larynx. Soft tissue hemorrhages, retroesophageal area.

of water during drowning). Buoyancy is affected by lung volume (104). One study showed that, at total lung capacity, all subjects floated in fresh and salt water (171). At functional residual capacity, i.e., a value approximating the lung volume of an unconscious or dead person, 7% of individuals floated in freshwater and 69% in sea-water. In fresh water, 5 kg (11 lb) of added weight would sink anyone regardless of lung volume; in sea water, 6.8 kg (15 lb) would suffice. Once a body starts to sink, it will continue sinking because hydrostatic pressure compresses gas in the chest and abdominal organs. Pressure compresses the chest, reducing residual volume and resulting in negative buoyancy (104).

Fig. 14. Submerged body. Injuries caused by leeches. (Courtesy of Dr. C. Rao, Regional Forensic Pathology Unit, Hamilton, Ontario, Canada.)

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