Sibaté, l’empoisonnement à l’amiante d’une municipalité colombienne

article grand public publié dans la revue Hesamag de l'European Trade Union Institut

Where are the landfilled sites? Methodological approaches to investigate the presence of asbestos in the soils of Sibaté (Cundinamarca, Colombia)

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The challenges of applying an Activity-Based Sampling methodology to estimate the cancer risk associated with asbestos contaminated landfilled zones

International audienceInhabitants of Sibaté (Colombia) report that between approximately 1975 and 1985 asbestos-containing materials (ACM) were dumped at different locations in the urban area of the municipality. Starting in around 1986, the dumping of materials resulted in landfilled zones, on top of which different facilities were then constructed. In a previous study, an underground friable asbestos layer was discovered in these landfilled zones. However, potential exposure to asbestos on the surface of landfilled zones in Sibaté has not been determined. In the current study, the U.S. EPA Activity-Based Sampling (ABS) methodology was adapted and applied in three scenarios located on potential landfilled areas in Sibaté, to estimate the current risk of exposure to asbestos through inhalation, and the resulting excess lifetime cancer risk (ELCR). For this purpose, generic ABS in a football stadium, and specific ABS in both a public playground and a school courtyard were conducted. Personal, area and blank samples were collected and analyzed using phase contrast microscopy (PCM) and transmission electron microscopy (TEM) following NIOSH 7400 and ISO 13794 methods, respectively. Exposure point concentrations were determined and compared against the action level for asbestos in air (ALAA), and were also used to calculate the ELCR of each scenario.A total of 25 airborne asbestos samples were collected, and 22 of these (12 personal samples, 7 area samples and 3 blank samples) were analyzed using PCM. Eighteen of these samples (12 personal, 3 area samples and 3 blank samples) were analyzed using TEM. The total asbestos structures concentration of personal samples ranged from non-detected to 0.326 S/cc (i.e., total asbestos structures counts ranged from 0 to 12). All samples had PCM-Equivalent asbestos structures concentrations below analytical sensitivity. Of the 22 samples analyzed, 18 were overloaded with particles.Although chrysotile and actinolite were identified in some personal samples, suggesting a potential risk of asbestos exposure, the ELCR was at U.S. EPA acceptable risk levels. Since the ABS methodology was applied in a limited number of scenarios and a small number of samples were collected, these results should be interpreted with caution and additional sampling campaigns are required to fully understand the risk of asbestos exposure in Sibaté. Methodological and analytical challenges encountered in the current study are discussed in detail, which could inform future ABS studies, not only in Sibaté, but also in other areas with asbestos-contaminated soils

Challenges applying activity-based sampling (ABS) in Sibaté, a Colombian asbestos contaminated town

International audienc

Challenges applying activity-based sampling (ABS) in Sibaté, a Colombian asbestos contaminated town

International audienc

Where are the landfilled zones? Use of historical geographic information and local spatial knowledge to determine the location of underground asbestos contamination in Sibaté (Colombia)

International audienceIntroduction: Sibaté is a municipality located in the central region of Colombia, where the first asbestos-cement facility of the country has been in operation since 1942. Both a malignant pleural mesothelioma cluster and landfilled zones with the presence of an underground friable asbestos layer have been identified in Sibaté. There is still limited knowledge regarding the history of the construction of landfilled zones, and what kinds of materials were deposited. The current study aims to improve our understanding of the history and characteristics of the landfilled zones present in Sibaté.Methods: Two participatory workshops with inhabitants of Sibaté were conducted to determine when the landfilled zones were built and their location. Information collected in participatory workshops was crossed with both topographic maps and aerial photographs, giving special attention to zones within the urban area of the municipality that in the past were inundated with water from El Muña Reservoir. An opportunistic soil sampling campaign was conducted in suspected landfilled zones that had not been previously sampled, during the replacement of pipelines of the drainage system ordered by the municipality.Results: The analysis of historical topographic maps, combined with the interpretation of aerial photographs, confirmed the disposal of residues in areas that were previously inundated with water from El Muña Reservoir, creating landfilled zones in the urban area of Sibaté. On top of these landfilled zones, a football stadium and a football field with an athletic track were built. The location of landfilled zones identified using geographic analysis was similar to the location identified analyzing maps constructed by inhabitants of Sibaté in participatory workshops. The four soil samples collected during an opportunistic sampling campaign confirmed the presence in new locations of the underground friable asbestos layer discovered in previous studies.Discussion: Based on the extension of the landfilled zones, the presence of friable asbestos in these areas, and the close proximity to a school and residential dwellings, there could have been major dispersion events of asbestos fibers in the urban area of Sibaté during the disposal of residue materials and the construction of the landfilled zones. Thus, important asbestos exposures may have occurred among residents of Sibaté, which is aggravated by the fact that during those years, more than 50% of the population of Sibaté was 25 years old or younger. Although the results of the current study improved our understanding of the processes and chronology associated with the landfilled zones, the uncertainty regarding their exact location remains significant. It is important to continue investigating the adverse health effects resulting from this potential asbestos exposure sourc

An Approach to Overcome the Limitations of Surveillance of Asbestos Related Diseases in Low- and Middle-Income Countries: What We Learned from the Sibaté Study in Colombia

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National Asbestos Profile for Colombia, a baseline of the current asbestos situation in the country

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Using GIS to Estimate Population at Risk Because of Residence Proximity to Asbestos Processing Facilities in Colombia

International audienc

Using GIS to Estimate Population at Risk Because of Residence Proximity to Asbestos Processing Facilities in Colombia

International audienc