Title

Forensic Characterization of Waterbodies in Malnad Region by Diatomological Mapping.

Authors

Surangama Chakraborty, Rajan S

 Abstract

Background: The 'Diatom test' is a reliable method which helps to determine the cause of death due to drowning based on quantitative and qualitative analysis of diatoms in human body and reference water sample. Positivity of this test is considered as an indicator of antemortem drowning. Methods: It was a prospective study where Samples were collected from ten different water bodies which included lakes, rivers, canals and reservoirs, for a period of one year and all the seasons were included by sampling once in two months and totally six samples of water were collected. The pH and temperature of water were recorded during sampling. From each of water samples, diatoms were extracted using concentrated nitric acid method. The sample was centrifuged, the resultant aspirate was poured over a clean microscopic glass slide, dried and analyzed with optical compound microscope fitted with light source at different magnifications. Result: The results show that, Total 22 genera of diatoms were identified. Most of them were pennales and few were centrales. Diatoms like Navicula, Cymbella and Synedra were present commonly in almost all water bodies, Melosira, Achnanthes and Brachysira were particularly seen in Lake water, Diatoma and Thalassiosira were commonly present in River water. Amphora and Ctenophora were commonly found in Lake water. Eunotia pectinalis and Tabellaria were particular to dam water. Thalassiosira, Surirella, Diatoma Cocconeis, Cyclotella were more commonly found in flowing water bodies. Melosira, Ctenophora, Brachysira, Achnanthes, Fragillaria were common to stagnant waters. Conclusion: Diatomological Mapping is a new tool in Forensic Biology as well as in Forensic Medicine, it must be constructed as organized research database.

 Keywords

Diatom test, Drowning, Diatomological mapping.

 DOI