Molecular Mechanism of Diatoms under Heavy Metal Stress: Environmental and Forensic Implications

Abstract Introduction: Diatoms, unicellular algae encased in silica shells, serve as highly sensitive bioindicators for water quality. Industrial sources of heavy metal pollution have a significant impact on the community. Because metal-induced alteration can make medical legal interpretation more difficult and affect the precision of investigation, this is important for forensics, because diatoms aid in locating drowning victims. Materials and Methods: Standardised laboratory settings were used to preserve the diatom samples that were taken from the Kasana River. For a duration of 15 days, each experimental group was exposed to 1 ppm of manganese, magnesium, lead and arsenic. Metal accumulation with diatom cells was quantified using inductively coupled plasma mass spectrometry, while morphological alterations were examined under an optical microscope. To assess the statistically significant variations in metal uptake and diatom viability over time, independent t -tests and repeated measures ANOVA were performed. Results: For each element examined, a time-dependent increase in metal accumulation was observed. Arsenic caused the most severe morphological defects, especially in frustule structure and demonstrated the highest uptake (0.59) among them. On the other hand, magnesium and manganese produced considerable absorption and discernible structural alteration, while lead had the least amount of intracellular accumulation. The type of morphological changes differs according to the metal in question. Conclusion: In conclusion, arsenic exhibited the most significant toxicity, likely due to its potential for absorption and interference with phosphate-dependent functions. These results lend credence to the use of diatoms as sensitive indicators of environmental contaminants and could be helpful in forensic analysis of aquatic pollution.