Forensic Analysis of Diatoms with Respect to Drowning Cases in the Western Ghats of Maharashtra

Abstract

Diatom analysis is a valuable tool in forensic science and it is helpful in diagnosis of drowning cases. For extraction and analysis of diatoms, the acid digestion test and centrifugation method is used mostly. Apart from this nitric acid digestion is a widely used method for extraction of diatoms. Other extraction technique like ultrasonic radiation, enzymatic digestion and physical method such as centrifugation and gradient centrifugation method are also employed for this purpose. The presence of diatoms in lungs and other vital organ can indicate the cause of death in drowning case. This topic explores the forensic analysis of diatoms in drowning incident in Western Ghats of Maharashtra. This region has its diverse aquatic environment, carrying a variety of diatoms species, making an ideal area for the studies. By providing a database of local diatoms forensic expert can give an idea of particular case investigation. This study includes the value of diatoms biodiversity in forensic science, especially in the drowning cases of unique ecological context of Maharashtra’s Western Ghats.

Introduction

Diatoms are a diverse group of photosynthetic algae found in freshwater, brackish, and marine environments worldwide. They have unique silica cell walls called frustules, with species-specific patterns, making them important ecological indicators and useful in forensic science. Diatoms play vital roles in oxygen production, food webs, carbon and nitrogen cycles, and silicon uptake.

In forensic science, especially in drowning cases, diatoms provide critical evidence. When a person drowns, diatoms from the water can enter the lungs and other organs, helping forensic experts confirm drowning as the cause of death, estimate time of submersion, and identify the drowning site. Diatom analysis is particularly valuable in distinguishing between death by drowning and post-mortem body disposal in water.

Studies emphasize the need for standardized protocols and advanced techniques—such as acid digestion, microwave digestion, and scanning electron microscopy—to improve the accuracy of diatom extraction and identification. Automated image analysis using machine learning is an emerging method to expedite and standardize diatom identification.

Research from regions like the Western Ghats and other parts of India has focused on creating regional diatom databases to enhance forensic reliability. Diatoms also serve as bioindicators for assessing water quality and ecological status.

Conclusion

Diatoms are unicellular, photosynthetic, eukaryotic organism that present in almost all water resources .They are mostly found in river, pond, lakes, ditches and in freshwater, brackish and marine waters as well as in well water, tap water, borewell water. Diatoms also occurs in the terrestrial habitat such as rocks, mosses, and soils, and even in caves. They can be either are planktonic or benthic. These particular qualities of diatoms are used in forensic science in a different way to identify and investigate crimes. There are approximately 15,000 known species of diatoms , but many of them remained undescribed. The diatom cell is enclosed in silica case with different shapes and ornamentations. The ornamentation is often species-specific, providing important information for identification and classification. Due to their small size and hard silica cell wall, they are easily found inside the body of organs of victims and settle down. During conducting the autopsy of the drowned dead body, the presence of diatoms in various tissues reveals whether it’s the case of antemortem or the postmortem. Diatoms analysis is crucial in drowning cases , especially in the regions with diverse aquatic environments like the western ghats of Maharashtra state. The Western ghats is an important biogeographic zone of India and one of the thirty-four global hotspots. Variation in the diversified group of the diatoms is observed here. some common species of the diatoms found in the western ghats include Stauroneis datarii, Stauroneis bahlsii, Stauroneis hamiltonii, Gomphonema rajaguruii, Luticola densistriata, Luticola indicensis, Luticola pseudofungiformis,Luticola bhimashankarensis,Luticola kaensis,Luticola yanensis, Luticola maharashtrensis. These are commonly found in the western region of Maharashtra, belonging to various locations within the northern western ghats, such as kass plateau and varandha ghat. Recently, a new freshwater diatom genus named Indiconema has been discovered in the Eastern and western ghats Other newly found diatom species includes Gomphonema rajagurujii, Stauroneis datarii, Stauroneis bahlsii, Saturoneis hamiltonii, luticola species. Therefore, diatom analysis is significant in determine the location, time since death, and whether it was ante-mortem or postmortem submersion. Various methods such as acid digestion, enzymatic digestion, and microwave digestion can be used for diatom extraction and analysis, aiding in forensic investigation related to drowning cases. A. Forensic Significance of Diatoms The study of diatom crucial in forensic science particularly, in in drowning case. Since different varieties of diatoms are found in different geographical areas, they helps determine the location of submersion, time since death and cause of death. As a person drowns, diatoms can be found in his lungs and other organs (such as femur bone), helping to determine whether it was postmortem or antemortem drowning. In case of postmortem drowning diatoms may not be found as significantly as in antemortem drowning. Diatoms can also link a suspect to crime scene, if the diatoms found in clothing, shoes, or object used by the suspect. These can be compared with the diatoms from the crime scene to determine whether they originated from the same location. Therefore, the unique properties of diatoms from different geographical area, help significantly to solve the water related criminal cases.

References

[1] P. C. Shahare, \"A Systematic Account of the Fresh Water Diatom from Chulband River of Gondia District, Maharashtra (India).,\" INTERNATIONAL JOURNAL OF RESEARCHES IN BIOSCIENCES, AGRICULTURE AND TECHNOLOGY, pp. 452-457, 2017. [2] Z. W. D. M. N. D. T. S. &. C. Z. Levkov, \"The use of diatoms in forensic science: advantages and limitations of the diatom test in cases of drowning.,\" The Geological Society of London on behalf of The Micropalaeontological Society eBooks., pp. 261-277, 2017. [3] E. V. A. et.al, \"The life of diatoms in the world’s oceans.,\" Nature article 459,185-192(2009), pp. 23-26, 2009. [4] M. &. K. B. Thacker, \"Response of diatoms to the changing water quality in the Myristica swamps of the Western Ghats, India.,\" MDPI, vol. 14, 2022. [5] S. K. B. N. &. A. A. S. Pal, \"Role of Diatoms in Forensics: A Molecular Approach.,\" in Insights into the World of Diatoms:From Essentials to Applications, 2023, pp. 143-163. [6] V. G. M. K. M. V. &. R. A. Vinayak, \"Diatoms as a great forensic tool in investigation of deaths due to drowning: a case study.,\" Journal of Forensic Medicine and Toxicology, pp. 51-54, 2010. [7] R. K. S. &. T. M. K. Singh, \"Forensic analysis of diatoms-A review.,\" Anil Aggrawal\'s Internet Journal of Forensic Medicine and Toxicology, vol. 7, 2006. [8] J. Soininen, \"Environmental and spatial control of freshwater diatoms – A review.,\" Diatom Research, vol. 22, no. 2, pp. 473-490, 2007. [9] S. A. S. E. I. K. P. S. A. S. A. &. S. C. A. Papadodima, \"Cardiovascular disease and drowning: autopsy and laboratory findings.,\" Hellenic Journal of Cardiology, 2007. [10] S. D. A. &. K. I. Uitdehaag, \"Extraction of diatoms from (cotton) clothing for forensic comparisons.,\" Forensic science international, pp. 112-116, 2010. [11] G. et.al, \"Freshwater diatom diversity in Deepor Beel-A Ramsarsite,\" Journal of Research in plant sciences, 2, 2., 2013. [12] K. Verma, \"Role of diatoms in the world of forensic science.,\" Journal Of Forensic Research, 2013. [13] S. L. C. W. J. D. W. W. S. S. H. &. Z. J. Hu, \"Detection of diatoms in water and tissues by combination of microwave digestion, vacuum filtration and scanning electron microscopy.,\" Forensic Science International, 2013. [14] P. S. E. K. A. &. V. K. Jakhar, \"Diatoms as cardinal keyto drowning case studies.,\" Journal of Forensic Medicine and Toxicology, 2015. [15] D. &. B. D. Rana, \"Isolation and characterisation of diatoms from waterbodies of Mumbai.,\" [16] T. M. T. C. A. T. &. B. T. Mwedzi, \" Stream biomonitoring: The role of diatoms, macroinvertebrates, and fish. In Emerging Freshwater Pollutants,\" in Emerging fresh water pollutants , 2022, pp. 09-24.IJCRR, vol. 8(17), 2016. [17] Y. &. Z. Y. Zhou, \"Chemical stability and instability of inorganic halide perovskites.,\" Energy & environmental science, pp. 1495-1511, 2019. [18] S. K. S. A. S. A. &. R. A. Pal, \"Diagnosing death with diatoms: a retrospective study of forensic cases in Himachal Pradesh, India.,\" International Journal of Medical Toxicology and Forensic Medicine , pp. 124-37, 2017. [19] P. M. Leth, \"Homicide by drowning.,\" Forensic Science, Medicine and Pathology, 2019. [20] A. K. A. &. C. L. G. Vijayan, \"Diatoms: A Review on its Forensic Significance.,\" Journal of Forensic Dental Sciences, vol. 12(3), pp. 197-200, 2020. [21] J. G. A. S. S. &. S. S. Shaikh, \"Diatomological Mapping of Aurangabad Region for Unrevealing Drowning Mystery.,\" Research Square, 2021. [22] P. H. S. S. H. S. K. &. K. S. Bodele, \"Diatoms as Indicators of Trophic State Change: A Comparative Study from Lakes of Bhandara District, Maharashtra, India.,\" Journal Of Geosciences Research , 2021. [23] B. P. C. A. &. D. T. Ludes, \"The diatom test in the field of forensic medicine: a review of a long-standing question.,\" International Journal of Legal Medicine, 1-9., 2024. [24] 1.-9. International Journal of Legal Medicine, \"Forensic significance in the cases of drowning deaths: an elaborative study.,\" nternational journal of forensic medicine and toxicological sciences, 6(4), 122-126., 2022. [25] P. M. M. D. C. P. &. B. A. Dahiya, \"A comprehensive review of forensic diatomology: contemporary developments and future trajectories.,\" Egyptian Journal of Forensic Sciences,, 2024.

Copyright

Copyright © 2025 Aniket Rahane , Devyani Parkhe . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.