Study of the diagnostic value of strontium, chloride, haemoglobin and diatoms in immersion cases.

Tests of haemoglobin (Hb), strontium (Sr) and chloride (Cl), as well as diatoms, toxicological and pathological studies were performed in biological samples from 133 immersion fatalities occurred since 1991 to 1996 in central and northern Spain. Hb, Sr, and Cl where analyzed in blood samples where increasing decomposition could be demonstrated in most of the cases. The samples were frequently accompanied with well documented forensic reports, including autopsies findings and other circumstances of the death. The goal of our study is to evaluate the difference of blood Sr concentration between the left and right side of the heart (LVSr-RVSr) as a marker of drowning. For this purpose, the cases investigated were classified in 'typical drowning' (TD) cases and 'atypical drowning' (AD) cases. This last group was used as a control. The comparison of the LVSr-RVSr between TD and AD cases was highly significant (P = 0.0002) in blood specimens extracted from cases occurred in putative drowning media where Sr concentration was higher than 800 micrograms/l. No significant differences were found comparing neither Cl nor Hb biventricular concentrations between TD and AD cases in blood samples extracted from bodies found in both fresh and seawater.