The study sample included 116 drowned subjects, and results for the sample group were compared with results obtained for three other groups: 22 subjects who died from causes other than asphyxia, 13 subjects who died of asphyxia (strangulation or hanging), and 23 healthy living subjects in whom the normal BS level was measured. Samples of water where drowned bodies had been found were analyzed to establish a relation with BS concentrations of drowned subjects. Histologically, each type of pulmonary lesion (congestion, edema, alveolar macrophages, alveolar hemorrhage, and emphysema aquosum) was evaluated semiquantitatively using a score according to the severity of the pathology, Then, a quantitative histomorphometric study was performed using a computer-assisted image and analyzer to measure length and thickness of alveolar walls and area and density of alveolar cavities. Mean values of BS levels in the 116 drowned subjects and water strontium concentrations were much higher than those in living individuals. Although ranges were wide, no overlap was found between values in drowned subjects and those in non-drowned individuals. Emphysema aquosum and to a lesser extent alveolar hemorrhage were the most significant histological changes in drowned and asphyxia groups, compared to nonasphyxia groups. 13 references, 3 tables, and 2 figures