Diatom analysis in victim's tissues as an indicator of the site of drowning

Abstract

The diagnosis of drowning is one of the most difficult in forensic pathology and previously we proposed criteria for a positive tissue analysis according to the qualitative and quantitative diatom investigations. In the positive cases, we studied the reliability of determining the site of drowning by comparing the diatom taxa found in the lung samples with those of the water samples or in the absence of these samples with the results of the water diatom monitoring programme set up in our region. In this study, we present two series of cases, the first is one of 20 corpses who died from accidental or suicidal drowning with known drowning site, and the second of 20 corpses for which the drowning site was unknown. The results showed that a concordance of the abundance of the diatom taxa in tissues compared to the site of drowning and their distribution relative to one another was 65% in the group where the site of drowning was known and 35% in the other group. The concordance of the individual distribution in the lungs of water diatom taxa may be an interesting method to guide the investigations for determining the site of drowning. The two limiting factors are the concentration of diatoms in the lungs and the development of a river monitoring programme in the district of the study.

A New Procedure for Diatom Extraction in the Diagnosis of Drowning

“…According to literature data [14,15] to assess the diagnosis of drowning, the analysis was considered positive when the presence of 20 diatoms was identified in each 100 microliter slide of a pellet obtained from one gram of kidney, lung, liver and brain. No false positive results were observed for the cases of death from other causes.…”

Diagnostic of Drowning in Forensic Medicine

“…In this aim, water samples must be collected at the drowning site (two samples of 100 ml) as well as algae scraped from stones present in the water. The samples are disposed in clean containers and the extraction and identification protocols on water and tissue samples were described by our group (Ludes et al, 1999). All reagents and glass containers must be checked for the absence of diatoms before use, and contamination from exogenous diatoms must be avoided by using diatom-free water and by protecting the organs during autopsy from the clothes of the victims and from the skin surface.…”

“…In fact, diatoms of more than 50 -60 µm in size rarely pass the alveoli-capillary barrier even after the rupture of the alveoli by the inhalation of water. The diagnostic of drowning can be achieved when the qualitative analysis shows that the algae found in the organ belongs to the water microflora and the quantitative criteria are fulfilled (Hendey, 1973(Hendey, , 1980Ludes et al, 1999).…”

Suda Boğulma Tanısında Kullanılan Yöntemlerin İrdelenmesi

“…Bunlar›n % 90'›n›n ise; bo¤ulma ortam›ndan al›nan örneklerde tespit edilen diatom tipi ile ayn› oldu¤unu bulmufllard›r (33). Bo¤ulma yeri bilinen olgu grubunda, nehrin diatom floras› ile akci¤er örneklerinde bulunan diatom tipi uygunluk oran› % 65, bo¤ulma yeri bilinmeyen olgularda ise nehrin diatom floras› ile uygunluk oran› % 35 olarak tespit edilmifltir (34). Di¤er bir çal›flmada; 133 suda bo¤ulma olgusunun 81'inin bulundu¤u suda diatom analizi yap›lm›fl ve 70 (% 86) olguda diatom pozitif bulunmufltur.…”