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

The diagnosis of drowning is one of the most difficult in forensic patholog y and previously we proposed criteria for a positive tissue analysis accord ing to the qualitative and quantitative diatom investigations. In the posit ive cases, we studied the reliability of determining the site of drowning b y comparing the diatom taxa found in the lung samples with those of the wat er 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 presen t two series of cases, the first is one of 20 corpses who died from acciden tal or suicidal drowning with known drowning site, and the second of 20 cor pses for which the drowning site was unknown. The results showed that a con cordance of the abundance of the diatom taxa in tissues compared to the sit e 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 dial-om t axa may be an interesting method to guide the investigations for determinin g the site of drowning. The two limiting factors are the concentration of d iatoms in the lungs and the development of a river monitoring programme in the district of the study.