Background <p>Disasters are events that spread throughout the affected regions’ surrounding areas. These events had immediate and long-term effects on Mariana and Brumadinho. This study aimed to assess the impact of mining disasters on the Unified Health System (SUS), based on the profile of hospitalization services used, the number of hospital admission authorizations, total costs, and the number of deaths in the municipalities of Mariana and Brumadinho before and after the disasters, using the chapters of the International Classification of Diseases (ICD-10).</p> Methods <p>Statistical analyses were performed using Student's t-test, which verified the significance of the means before and after the disaster regarding SUS hospitalization services.</p> Results <p>The results indicate an increase in hospitalizations in the ICD chapters related to mental and behavioral disorders, perinatal conditions, and abnormal symptoms and test findings. In Brumadinho, the data point to an increase in the number of hospitalizations and deaths due to parasitic diseases, the latter also occurring in Mariana.</p> Conclusions <p>In any case, the disaster generated needs that would not have been noticed or observed before, which were mainly reflected in infectious and parasitic diseases, suggesting that changes in the environment can cause serious changes in the vector cycle. These data are evident in both Mariana and Brumadinho in terms of the number of deaths, but Brumadinho had a much higher than average increase due to the COVID-19 pandemic. Although daily life in both cities has been altered, the human consequences in Brumadinho were more severe than those in Mariana. Such environmental changes increase healthcare and SUS costs.</p>