Vitreous cardio-renal biochemical parameters and minerals as biomarkers for forensic discrimination of salt water drowning

Background: Drowning is an episode occasioned by respiratory disturbances resulting from either submersion or immersion in liquid. The World Health Organization ranked drowning globally as the third cause of unintentional death, with an estimated annual mortality of about 236,000. Statistics on drowning in Nigeria are not available, but it is quite prominent amongst causes of unintentional death. Poor discriminatory measures of drowning resulting from suicidal, homicidal, or accidental causes are empirically handicapped due to scientific gaps. In addition, the type of water bodies drowning occurs is very important in drowning investigations. Aim and Objectives: This study was designed to use vitreous cardiorenal biomarkers and minerals to substantiate drowning due to saltwater intoxication. Methodology: The sample size was determined by Mead's formula, resulting in the use of twenty-four (24) albino rabbits randomized into four groups: the Control Death (CD) group, the Chloroform Death (CFD) group, the Post-mortem Drowned Death (PDD) group, and Saltwater Drowned Death (SDD) group. The saltwater was harvested from the Brass Sea of Bayelsa State, Nigeria, whereas vitreous humour was extracted using the Coe method. The vitreous biochemical parameters employed included creatinine, urea, uric acid, electrolytes, Lactate Dehydrogenase (LDH), troponin I (TnI), and creatine kinase. Results: The results show a significant increase (p < 0.05) in vitreous zinc, creatinine, and creatine kinase concentrations, whereas vitreous calcium concentration decreased in the SDD group compared to other groups. Similarly, vitreous calcium, sodium, and magnesium strictly and significantly increased (p < 0.05) in the PDD group compared to all the different groups. Parameters such as vitreous chloride and LDH concentrations increased significantly (p < 0.05) in the PDD and CFD groups compared to the other groups, though more conspicuous in the latter. Furthermore, the vitreous activities of creatinine kinase in the CFD and SDD groups significantly increased (p < 0.05) compared to the other groups. Also, a significant increase was noted in the vitreous activities of troponin I in the PDD and SDD groups when compared to the other groups. Conclusion: Conclusively, the observed distortions could be harnessed as adjunct investigations in the discrimination of death due to saltwater drowning.