An asbestos contaminated town in the vicinity of an asbestos-cement facility: The case study of Sibaté, Colombia

Introduction The asbestos industry began operations in Colombia in 1942, with an asbestos-cement facility located in the municipality of Sibate. In recent years residents from Sibate have been complaining about what they consider is an unusually large number of people diagnosed with asbestos-related diseases in the town. A study to analyze the situation of Sibate started in 2015, to verify if the number of asbestos related diseases being diagnosed were higher than expected, and to identify potential asbestos exposure sources in the town. Methods A health and socioeconomic survey was implemented door-to-door to identify potential asbestos-related diseases. Several self-reported mesothelioma cases were identified, and for confirmation purposes, copies of the medical record with the histopathology report were obtained. A panel of six physicians analyzed the medical records. Information of validated cases was used to estimate the male and female age-adjusted incidence rate for Sibate. Based on reports of the existence of potential asbestos-contaminated landfills, topographic maps, a digital elevation model, and current satellite images were crossed using a geographic information system to identify potential landfilled areas, and soils samples were collected in some of these areas. Results A total of 355 surveys were completed, and 29 self-reported mesothelioma cases were identified. Twenty-five of these cases have been persons who had lived at some moment of their lives in Sibate. It was possible to obtain copies of the medical diagnosis for 17 cases. Of these, the panel of physicians classified 15 cases as certain pleural mesothelioma, one as probable, and one as not mesothelioma. Based on this information, the estimated age-adjusted incidence rate of mesothelioma in Sibate was 3.1 × 105 persons-year for males and 1.6 × 105 persons-year for females. These rates are high in comparison to those reported in other cities, regions, and countries of the world. Using geographic information systems, landfilled zones in the urban area of Sibate were identified, on top of which a school and different sports facilities were built. The analysis of four soil samples collected in landfilled zones, confirmed the existence of an underground layer of friable and non-friable asbestos. Conclusion The collected evidence suggests the presence of a malignant pleural mesothelioma cluster in Sibate.