ABSTRACT
Objetivo: Este estudio evaluó el efecto de la proximidad a fuentes industriales de contaminación del aire sobre la aparición de clústeres de casos de cáncer infantil en el Área Metropolitana del Valle de Aburrá, del departamento de Antioquia, durante el período 2000-2015. Metodología: La información de casos de cáncer infantil en menores de 15 años residentes del área metropolitana se obtuvo del Registro Poblacional de Cáncer de Antioquia, de dicho periodo. Se identificaron 32 conglomerados industriales, a partir del inventario de la autoridad ambiental local. Se realizaron pruebas de escaneo circular de Kulldorf locales y focalizadas, para detectar clústeres de cáncer infantil en los municipios y alrededor de los conglomerados industriales respectivamente. Se usó un modelo de regresión multivariable ajustado por estrato socioeconómico, para evaluar el efecto de las variables espaciales. Resultados: La tasa de incidencia específica en el Valle de Aburrá para el periodo evaluado fue de 117,13 casos por millón de niños menores de 15 años. Las tasas de incidencia más altas se presentaron en los municipios de Medellín y Sabaneta. La prueba de Kulldorf identificó 12 clústeres espaciales y 8 espacio-temporales con significación estadística en 7 de los municipios, particularmente en Bello y Medellín. Las pruebas focalizadas identificaron clústeres alrededor de 20 conglomerados industriales. En los modelos multivariables, un conglomerado en Bello evidenció asociación estadísticamente significativa e inversa entre la incidencia y la distancia al conglomerado con direccionalidad sureste. Conclusión: Algunos conglomerados espacio-temporales de cáncer infantil en el Área Metropolitana del Valle de Aburrá entre 2000 y 2015 están relacionados con proximidad a fuentes industriales de contaminación del aire.
Objective: This study evaluated the effect of proximity to industrial sources of air pollution on the occurrence of clusters of childhood cancer cases in the Aburrá Valley Metropolitan Area, Department of Antioquia, during the 2000-2015 period. Methodology: The information on childhood cancer cases in children under 15 years of age residing in the metropolitan area was obtained from the Registro Poblacional de Cáncer de Antioquia (Antioquia Cancer Population Registry) for that period. 32 industrial clusters were identified based on the local environmental authority's inventory. Local and targeted Kulldorff's circular scan tests were performed to detect childhood cancer clusters in the municipalities and surrounding the industrial clusters, respectively. We used a multivariate regression model adjusted for socioeconomic strata to assess the effect of spatial variables. Results: The specific incidence rate in the Aburrá Valley for the evaluated period was 117.13 cases per million children under 15 years of age. The highest incidence rates occurred in the municipalities of Medellín and Sabaneta. The Kulldorff test identified 12 spatial clusters and 8 space-time clusters that were statistically significant in 7 municipalities, particularly in Bello and Medellín. The targeted tests identified childhood cancer clusters surrounding 20 industrial clusters. In multivariate models, an industrial cluster in Bello showed a statistically significant inverse association between incidence and distance from the industrial cluster toward the southeast. Conclusion: Some space-time childhood cancer clusters in the Aburrá Valley Metropolitan Area between 2000 and 2015 are related to proximity to industrial sources of air pollution.
Objetivo: Este estudo avaliou o efeito da proximidade a fontes industriais de poluição do ar sobre a aparição de agrupações de casos de câncer infantil na Área Metropolitana do Valle de Aburrá, do departamento de Antioquia, durante o período 2000-2015. Metodología: A informação de casos de câncer infantil em menores de 15 anos residentes da área metropolitana foi obtida do Registro Populacional de Câncer de Antioquia, de tal período. Foram identificados 32 conglomerados industriais, a partir do inventário da autoridade ambiental local. Foram realizados testes de varredura circular de Kulldorf locais e focalizados, para detectar agrupações de casos de câncer infantil nos municípios e ao redor dos conglomerados industriais, respectivamente. Foi usado um modelo de regressão multivariável ajustado por nivel socioeconômico, para avaliar o efeito das variáveis espaciais. Resultados: A taxa de incidência específica no Valle de Aburrá para o período avaliado foi de 117,13 casos por milhão de crianças menores de 15 anos. As maiores taxas de incidencia apresentaram-se nos municípios de Medellín e Sabaneta. O teste de Kulldorf identificou 12 agrupações de casos espaciais e 8 espaço-temporais com significação estatística em 7 dos municípios, particularmente em Bello e Medellín. As provas focalizadas identificaram agrupações de casos ao redor de 20 conglomerados industriais. Nos modelos multivariáveis, um conglomerado em Bello evidenciou associação estatisticamente significativa e inversa entre a incidência e a distância com o conglomerado orientado ao sudeste. Conclusão: Algumas agrupações de casos espaço-temporais de câncer infantil na Área Metropolitana do Valle del Aburrá entre 2000 e 2015 estão relacionadas com a proximidade a fontes industriais de poluição do ar.
ABSTRACT
Acute leukemia is the most common childhood cancer and has been associated with exposure to environmental carcinogens. This study aimed to identify clusters of acute childhood leukemia (ACL) cases and analyze their relationship with proximity to industrial sources of air pollution in three capital cities in Colombia during 2000-2015. Incident ACL cases were obtained from the population cancer registries for the cities of Bucaramanga, Cali, and Medellín. The inventory of industrial sources of emissions to the air was obtained from the regional environmental authorities and industrial conglomerates were identified. The Kulldorf's circular scan test was used to detect city clusters and to identify clusters around industrial conglomerates. Multivariable spatial modeling assessed the effect of distance and direction from the industrial conglomerates controlling for socioeconomic status. We identified industrials sectors within a buffer of 1 km around industrial conglomerates related to the ACL clusters. Incidence rates showed geographical heterogeneity with low spatial autocorrelation within cities. The spatio-temporal tests identified one cluster in each city. The industries located within 1 km around the ACL clusters identified in the three cities represent different sectors. Exposure to air pollution from industrial sources might be contributing to the incidence of ACL cases in urban settings in Colombia.
Subject(s)
Air Pollutants/adverse effects , Air Pollution/adverse effects , Environmental Monitoring , Leukemia/chemically induced , Residence Characteristics/statistics & numerical data , Air Pollution/analysis , Child , Cities , Colombia/epidemiology , Female , Humans , Leukemia/epidemiology , Male , Particulate Matter/analysis , Small-Area AnalysisABSTRACT
BACKGROUND: Air pollutants are considered carcinogenic to humans. In some European countries, an association between industrial air pollution and childhood cancer has been established. This relationship has not been addressed in Latin America, despite the spatial variability of air pollutants that may limit the extrapolation of the results to other geographical areas. OBJECTIVE: To conduct a spatial analysis of the relationship between childhood cancer and proximity to industrial sources of air pollution in a metropolitan area of Colombia. METHODS: Incident cases of childhood cancers were obtained from the Population-based Cancer Registry of the Metropolitan Area of Bucaramanga during 2000-2015. Local and focused cluster tests were used for the detection of spatial clusters, and the Poisson multivariable model was used to evaluate the combined effects of spatial variables. RESULTS: The Kulldorff's focused test found a significant spatial cluster (P < 0.001) around one industrial agglomerate and the multivariable model results suggests that the distance effect is modified by the directional effect of the wind. CONCLUSION: A spatial cluster of incident cases of childhood cancer occurred in the municipality of Bucaramanga, Colombia. Our finding supports the hypothesis that childhood cancer might be related with industrial air pollution exposure in a Latin American city.
Subject(s)
Air Pollution/analysis , Disease Hotspot , Environmental Exposure/adverse effects , Neoplasms/epidemiology , Spatial Analysis , Air Pollutants/analysis , Child , Child, Preschool , Colombia/epidemiology , Female , Humans , Male , Manufacturing and Industrial Facilities , Particulate Matter/analysisABSTRACT
BACKGROUND: Leukemia is the most common cancer in childhood. The estimated incidence rate of childhood leukemia in Colombia is one of the highest in America and little is known about its spatial distribution. PURPOSE: To explore the presence of space-time clustering of childhood leukemia in Colombia. METHODS: We included children less than 15 years of age with confirmed diagnosis of acute leukemia reported to the national surveillance system for cancer between 2009 and 2017. Kulldorff's spatio-temporal scan statistics were used with municipality and year of diagnosis as units for spatial and temporal analysis. RESULTS: There were 3846 cases of childhood leukemia between 2009 and 2017 with a specific mean incidence rate of 33 cases per million person-years in children aged 0-14 years. We identified five spatial clusters of childhood leukemia in different regions of the country and specific time clustering during the study period. CONCLUSION: Childhood leukemia seems to cluster in space and time in some regions of Colombia suggesting a common etiologic factor or conditions to be studied.
