Diatoms in forensic analysis: A practical approach in rats.

Area of Science:

• Forensic Science
• Environmental Science
• Microbiology

Background:

• Diagnosing drowning is challenging due to a lack of definitive indicators.
• Diatom analysis is a potentially valuable but debated tool for drowning confirmation.

Purpose of the Study:

• To assess the association between diatoms and drowning in rat tissues.
• To evaluate the impact of different drowning media on diatom recovery.
• To optimize diatom recovery methods for forensic applications.

Main Methods:

• Wistar rats were drowned in seawater, lake water, or river water, with controls immersed post-mortem.
• A modified acid digestion method was used for diatom recovery from water and rat tissues.
• Diatomological mapping was performed using water samples from specific Spanish locations.

Main Results:

• Diatoms were successfully recovered from all water samples and matched with drowned rat tissues.
• Significant differences in diatom counts were observed between drowned and control groups across tissues.
• Histological examination of lung tissue provided complementary diagnostic information.

Conclusions:

• The diatom test is a feasible and reliable method for diagnosing drowning.
• Proper contamination avoidance and interpretation alongside other methods are crucial for accuracy.
• This study supports the utility of diatom analysis in forensic investigations of drowning.