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.

Introduction: The asbestos industry began its operations in Colombia in 1942 with the establishment of an asbestos-cement facility in Sibaté, located in the Department of Cundinamarca. Despite extensive asbestos use and production in Colombia, the country lacks a reliable epidemiological surveillance system to monitor the health effects of asbestos exposure. The Colombian health information system, known as SISPRO, did not report mesothelioma cases diagnosed in the municipality, posing a significant challenge in understanding the health impacts of asbestos exposure on the population of Sibaté. Methods: To address this issue, an active surveillance strategy was implemented in Sibaté. This strategy involved conducting door-to-door health and socioeconomic structured interviews to identify Asbestos-Related Diseases (ARDs). Validation strategies included a thorough review of medical records by a panel of physicians, and the findings were communicated to local, regional, and national authorities, as well as the general population. Results: The active surveillance strategy successfully identified a mesothelioma cluster in Sibaté, revealing the inadequacy of the existing health information system in monitoring asbestos-related diseases. The discovery of this cluster underscores the critical importance of implementing active surveillance strategies in Colombia, where governmental institutions and resources are often limited. Conclusion: The findings of this study emphasize the urgent need for Colombia to establish a reliable epidemiological surveillance system for asbestos-related diseases (ARDs). Active surveillance strategies can play a crucial role in identifying mesothelioma clusters and enhancing our understanding of the health effects of asbestos exposure in low- and middle-income countries.

The Italian Experience in the Development of Mesothelioma Registries: A Pathway for Other Countries to Address the Negative Legacy of Asbestos.

Asbestos (all forms, including chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophyllite) is carcinogenic to humans and causally associated with mesothelioma and cancer of the lung, larynx, and ovary. It is one of the carcinogens most diffuse in the world, in workplaces, but also in the environment and is responsible for a very high global cancer burden. A large number of countries, mostly with high-income economies, has banned the use of asbestos which, however, is still widespread in low- and middle-income countries. It remains, thus, one of the most common occupational and environmental carcinogens worldwide. Italy issued an asbestos ban in 1992, following the dramatic observation of a large increase in mortality from mesothelioma and other asbestos-related diseases in exposed workers and also in subjects with non-occupational exposure. A mesothelioma registry was also organized and still monitors the occurrence of mesothelioma cases, conducting a case-by-case evaluation of asbestos exposure. In this report, we describe two Italian communities, Casale Monferrato and Broni, that faced an epidemic of mesothelioma resulting from the production of asbestos cement and the diffuse environmental exposure; we present the activity and results of the Italian mesothelioma registry (ReNaM), describe the risk-communication activities at the local and national level with a focus on international cooperation and also describe the interaction between mesothelioma registration and medical services specialized in mesothelioma diagnosis and treatment in an area at high risk of mesothelioma. Finally, we assess the potential application of the solutions and methods already developed in Italy in a city in Colombia with high mesothelioma incidence associated with the production of asbestos-cement materials and the presence of diffuse environmental asbestos pollution.

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

The recent enactment of the law banning asbestos in Colombia raises a significant number of challenges. The largest factories that have historically processed asbestos include five asbestos-cement facilities located in the cities of Sibaté (Cundinamarca), Cali (Valle del Cauca), and Barranquilla (Atlántico), and Manizales (Caldas), which has two, as well as a friction products facility in Bogotá D.C. An asbestos chrysotile mine has also operated in Colombia since 1980 in Campamento (Antioquia). In the framework of developing the National Asbestos Profile for Colombia, in this study, we estimated the population residing in the vicinity of asbestos processing plants or the mine and, therefore, potentially at risk of disease. Using a geographic information system, demographic data obtained from the last two general population censuses were processed to determine the number of people living within the concentric circles surrounding the asbestos facilities and the mine. In previous studies conducted in different countries of the world, an increased risk of asbestos-related diseases has been reported for people living at different distance bands from asbestos processing facilities. Based on these studies, circles of 500, 1000, 2000, 5000, and 10,000 m radii, centered on the asbestos processing facilities and the mine that operated in Colombia, were combined with the census data to estimate the number of people living within these radii. Large numbers of people were identified. It is estimated that in 2005, at the country level, 10,489 people lived within 500 m of an asbestos processing facility or mine. In 2018, and within a distance of 10,000 m, the number of people was 6,724,677. This information can aid public health surveillance strategies.

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).

INTRODUCTION: 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 source.

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

Inhabitants 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.

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 Sibaté. In recent years residents from Sibaté 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 Sibaté 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 Sibaté. 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 Sibaté. 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 Sibaté 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 Sibaté 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 Sibaté.

Types of homes and ways of life: a territorial analysis of the environmental determinants that factor into the proliferation of malaria vectors in the rural region of Allada in Benin.

INTRODUCTION: Anthropogenic factors, as well as environmental factors, can explain fine-scale spatial differences in vector densities and seasonal variations in malaria. In this pilot study, numbers of Anopheles gambiae were quantified in concessions in a rural area of southern Benin, West Africa, in order to establish whether vector number and human factors, such as habitat and living practices, are related. METHODS: The courtyard homes of 64 concessions (houses and private yards) were systematically and similarly photographed. Predefined features in the photographed items were extracted by applying an analysis grid that listed vector resting sites or potential breeding sites and also more general information about the building materials used. These data were analysed with respect to entomological data (number of mosquitoes caught per night) using the Kruskal-Wallis test, Pearson correlation coefficients, and analysis of covariance (ANCOVA). RESULTS: Three recurrent habitat/household types and living practices were identified that corresponded to different standards of living. These were related to the average number of mosquitoes captured per night: type I=0.88 anopheles/night; type II=0.85; and type III 0.55, but this was not statistically significant (Kruskal-Wallis test; p=0.41). There were no significant relationships between the number of potential breeding sites and number of mosquitoes caught (Pearson's correlation coefficient=-0.09, p=0.53). ANCOVA analysis of building materials and numbers of openings did not explain variation in the number of mosquitoes caught. CONCLUSIONS: Three dwelling types were identified by using predetermined socio-environmental characteristics but there was no association found in this study between vector number and habitat characteristics as was suspected.