Revista de investigación forense

Role of Diatoms in the World of Forensic Science

Abstract

Kapil Verma

This article reviews the forensic aspects of Diatoms analysis and acid digestion method for diatoms extraction. A body recovered from the water does not necessarily imply that death was due to drowning. If the person is still alive when entering the water, diatoms will enter the lungs if the person inhales water and drowns. The diatoms are then carried to distant parts of the body such as the brain, kidneys, lungs and bone marrow by circulation. If the person is dead when entering the water, then there is no circulation and the transport of diatom cells to various organs is prevented because of a lack of circulation and diatoms cannot enter the body. When a body is recovered from water, there is usually a suspicion whether it was a case of ante-mortem or post-mortem drowning i.e. whether the body was drowned before or after death. In these medico legal cases, presence of diatoms in the body tissues is very useful evidence. In drowning related death cases, a correlation between the diatoms extracted from bone marrow and liver/lungs) samples and the samples obtained from drowning medium have to be established for the successful determination of drowning site in Forensic laboratories. Diatom analysis should be considered positive when number of diatoms is above a minimal established limit; 20 diatoms/ 100 μl of pellet obtained from 10 gm of lung samples and 50 diatoms from other organs and further matching of diatoms from bone marrow and drowning site can strengthen this supportive evidence and a positive conclusion can be drawn whether person was living or not when drowned. Detection of diatoms in the bone marrow is a proof that the individual was alive when entered the water.