IJUP08 - Universidade do Porto

New approaches to the diagnostic of death by drowning based on
trace element levels in blood of the cardiac cavities
F. Pereira 1 , T. Magalhães 2 , A. Almeida 1 , A. Santos 2 and B. Santos 3
1 REQUIMTE, Serviço de Química-Física, Faculdade de Farmácia, Universidade do Porto, Portugal.
2 Serviço de Medicina Legal, Faculdade de Medicina, Universidade do Porto, Portugal. Serviço de
Patologia Forense, Instituto Nacional de Medicina Legal, I.P. – Delegação do Norte.
3 Serviço de Patologia Forense, Instituto Nacional de Medicina Legal, I.P. – Delegação do Centro.
Investigation of bodies recovered out of water is a common medico-legal task. However,
the key question whether the victim died due to drowning or was simply put into the water
after death can frequently not easily be solved [1]. The difficulties are related to the few
macroscopic findings seen during the autopsy examination, usually non-specific or
doubtful. Additionally, the putrefaction, frequently present, increases the uncertainty of the
diagnostic.
Several approaches to support the diagnosis of death by drowning have been investigated.
Beyond the classical detection of diatoms in blood and tissues, one of those approaches
may be the determination of trace elements (TE) in blood, using highly sensitive analytical
techniques. This is based on the following principle: several TE typically found in water
are not present (or are present at much lower concentration) in human body. Therefore, in
the case of death by submersion in water, those TE will become increased in the body. In
this context, one of the elements that has gained broad acceptance is strontium (Sr), since it
is, from the studied TE, the one that shows the higher ratio [Sr] in water / [Sr] in body
fluids or tissues. For example, for seawater, the ratio [Sr] in water / [Sr] in blood is ca. 267,
which makes it a highly useful indicator [2]. Additionally, some studies have also shown
that a significant difference can be found between the Sr concentration in the left ventricle
([Sr]LV) and the right ventricle ([Sr]RV) blood, and the use of the two variables ([Sr]LV and
[Sr]LV-[Sr]RV) have been proposed. However, the usefulness of Sr determination in case of
deaths by submersion in freshwaters is not so clear, because of the lower Sr concentrations
in these waters [3].
In the last few years, a highly sensitive instrumental technique, the so-called Inductively
Coupled Plasma-Mass Spectrometry (ICP-MS), has gained increased importance in
forensic studies. Our current work regards its utilization in the determination of TE in
blood of the cardiac cavities and the water where the corpses were found in order to
increase the certainty of the diagnostic of death by drowning. Main specific objectives are
the evaluation of the difference between Sr and other TE concentrations in LV and RV
blood as a marker of drowning and the identification of other TE (beyond Sr) that could be
an advantageous marker of drowning, particularly in freshwater.
References:
[1] Piette, M.H. and De Letter, E.A. (2006), Drowning: still a difficult autopsy diagnosis, Forensic
Science International, 163(1-2), 1-9.
[2] Azparren, J.E., Ortega, A., Bueno, H. and Andreu, M. (2000), Blood strontium concentration related
to the length of the agonal period in seawater drowning cases. Forensic Science International, 108(1),
51-60.
[3] Azparren, J.E., Fernandez-Rodriguez, A. and Vallejo, G. (2003), Diagnosing death by drowning in
fresh water using blood strontium as an indicator, Forensic Science International, 137(1), 55-59.
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