LAUSR

Abstract The collapse of the B1 Dam of VALE SA mining company in Brumadinho, Minas Gerais, Brazil was the largest humanitarian disaster and occupational accident in the country’s history, and it posed challenges regarding the management and identification of multiple victims. We evaluated the impact of the iron ore tailings on the victims’ bodies. We examined the scientific identification of the victims and the dynamics of the disaster over the 1st year after it occurred. We also determined the socio-demographic profiles of the victims. In this retrospective, cross-sectional study, we investigated the expert reports of the victims’ biological remains from 25 January 2019 to 25 January 2020. We analysed the socio-demographic data, identification methods, identification status, identification time, and necroscopic information. During the study period, 259 of 270 victims were identified, and 603 biological materials were analysed; among them, 86.2% were body parts and 13.8% were whole bodies. Of the total cases registered that year, 476 (78.9%) were submitted during the first 10 weeks after the disaster. Friction ridge analysis accounted for 67.9% of primary identifications and DNA analysis did so for 91.6% of re-identification cases. Body dismemberment was 3.4 times greater among mine workers than among community victims. Adult males accounted for the greatest number of victims (P < 0.001). Polytraumatic injury was the prevalent single cause of death. Necropsy examination revealed the occurrence of asphyxia in 7% of cases. The higher number of fatalities and greater dismemberment among employees than with community residents underlines the occupational dangers in the mining industry and clarifies the dynamics of the disaster. In the initial weeks after the dam collapsed, friction ridge analysis was the most appropriate method for identification. Subsequently, DNA analysis became the most-used technique for identification and re-identification owing to the great volume of body parts and decomposed biological tissue. Autopsy allowed diagnosis of the causes of death to be clarified according to the Brazilian criminal legal system. Key points The collapse of B1 Dam of VALE SA mining company in Brumadinho was the greatest humanitarian disaster and occupational accident in the country’s history. This article examined the challenges and solutions regarding the management and identification of the disaster’s many victims. Of the victims, 95.9% were identified during the 1st year after the disaster; 78.9% were identified in the first 10 weeks. Polytraumatic injury accounted for 86.2% of deaths; it was observed more frequently among mine employees than among community residents. In the first weeks after the disaster, friction ridge analysis was mostly used for identification; subsequently, DNA analysis was employed for most identification and re-identification cases.