[en] Introduction: Chañaral, a coastal city located in the Atacama Region of Chile, has a beach severely polluted by the tailings of a large copper mine, which were dumped into the Rio Salado from 1938 to 1989 and carried to Chañaral Bay without preprocessing treatment. This pollution created a large artificial beach that currently covers an approximate surface area of 12 km2, representing one of Chile's most significant environmental disasters. The impact of these tailings on the marine and coastal ecosystem have been measured and studied extensively, however effects on the inhabitants living adjacent to the tailings have not been explored thoroughly. Human populations living near mine tailings are at risk for various health problems. In the northern Chilean city of Chañaral, prevailing spring and summer winds carry particulate matter (PM) that affects the population. Aims: The main aims was to estimate the association between environmental PM and lung function among schoolchildren living at Chañaral city in the Atacama Region of Chile, from 2012 to 2013. Secondary, we measured PM2.5 mass and its metal/metalloids composition in indoor and outdoor schools microenvironments in different seasons of the year. Methods: To main objective a longitudinal panel study of schoolchildren aged 6 to 15 years (n=110) was performed. PM levels (μg/m3) were measured continuously from November 2012 to May 2013 (182 days). Lung function was evaluated with spirometry testing performed every 2 weeks, values studied were forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), and forced expiratory flow during the middle portion of the FVC (FEF25-75). In addition, meteorological, anthropometric, and sociodemographic variables were measured. We fitted generalized estimating equations (GEE) model to estimate associations between lung function and air pollution using different time-lag to fine (PM2.5) particulate matter concentrations. Simultaneously, we measure and compare fine particulate matter levels (PM2.5) and metallic composition in school microenvironments. PM2.5 were measured outdoors and indoors at six schools during the summer, fall, and winter of 2012 and 2013. Schools were visited during teaching hours on two consecutive days. Metal content was determined using X-ray fluorescence. Results: The analysis included 506 spirometry tests that met American Thoracic Society/European Respiratory Society (ATS/ERS) quality criteria. In the unadjusted model, there were significant negative associations for average and maximum PM2.5 levels with FEV1, FVC, and PEF, and for maximum PM10 levels with FEV1 and PEF. In the adjusted model, the negative association between PM2.5 and FVC remained significant. We found a negative association between the temporal variation of PM2.5 and changes in lung function specifically by lag12 max with FEV1 (β-0.75 ml, 95%CI -1.4, -0.03 for a 1 -unit increase in PM2.5); lag4 avg and lag12 avg with FVC (β-2.42 ml, 95%CI -4.7, -0.1; and β-5.07 ml, 95%CI - 8.9, -1.1, respectively), as were lag4 max, lag12 max, and lag24 max with FVC (β-1.74 ml, 95%CI -2.7, -0.8; β-1.90 ml, 95%CI -2.8, -1.01; and β-2.01 ml, 95%CI -2.9, -1.03, respectively), and PEF which was negatively associated with lag24 max (β-2.93 ml/sec, 95%CI -5.7, -0.1). After adjusting, only the negative associations between lag12 max and lag24 max PM2.5 levels and FVC remained significant. To microenvironment indoor pollution study, we found during summer, fall, and winter, indoor concentrations varied from 12.53-72.37 μg/m3, 24.06-80.22 μg/m3 and 21.85-110.53 μg/m3. Outdoor concentrations varied from 11.86-181.73 μg/m3, 14.06-58.44 μg/m3 and 21.38-93.07 μg/m3 in summer, fall, and winter respectively. Indoor/outdoor ratios by season were 0.22-0.28 in summer, 0.38-0.92 in fall, and 0.89-1.28 in winter. Metals with the highest indoor concentrations were Ca> S> Si> Cl> Na> Al> Fe> K> Mg> Ti> Cu> Zn> and, Cr. PM2.5 levels were elevated in indoor microenvironments in fall and winter months, at times exceeding national standards. During the summer, outdoor school environments exceeded recommendations. Conclusion: Our results suggest that schoolchildren exposed to fine particulate matter from tailings deposited in the bay of Chañaral have their forced vital capacity decreased, which would affect their present and future lung development, increasing the risk of developing chronic respiratory diseases. We found a negative association between the temporal variation of PM2.5 and changes in lung function specifically on forced vital capacity. On the other hand, we demonstrated that indoor air quality in schools microenvironments of Chañaral was closely associated with outdoors air pollution and that main source would be related to mine tailings presents in the bay.

[es] Introducción: Producto de la gran actividad minera de la III Región de Atacama en el norte de Chile se vertieron al curso del rio El Salado millones de toneladas de relaves (con alto contenido de metales) sin tratamiento al curso del Rio Salado, los que fueron a dar a la bahía de la ciudad de Chañaral formando una extensa playa artificial. Estos relaves han producido un marcado efecto deletéreo sobre la flora y fauna marina del sector y en la calidad de vida de las poblaciones que viven adyacentes a esta playa, debido a que por acción eólica se levanta material particulado (MP) que es transportado hacia la ciudad. Objetivos: El objetivo primario fue evaluar la asociación entre la exposición diaria a material particulado fino (MP2.5) y la función respiratoria de niños de 6 a 15 que viven próximos a una playa masivamente contaminada con relaves mineros. Secundariamente, se caracterizó las concentraciones másica y composición metales/metaloides del MP2.5 en microambientes interiores y exteriores escolares. Métodos: Entre diciembre y mayo (2012-2013) se realizó un estudio longitudinal tipo panel en una muestra representativa de 140 escolares entre 6 y 15 años. En el inicio del estudio se aplicó un cuestionario sobre salud respiratoria, condiciones ambientales y características de la familia. Seguidamente fueron sometidos a exámenes de función respiratoria cada 2 semanas. Simultáneamente durante el periodo de estudio se monitorearon y registraron diariamente los niveles ambientales de MP2.5 por un periodo de 6 meses y se colectó MP2.5 en diferentes microambientes escolares en verano, otoño e invierno durante la jornada escolar. La determinación de metales/metaloides se realizó por medio de fluorescencia de rayos X. Las asociaciones entre la exposición diaria a MP2.5 y los cambios en la función pulmonar fueron estimadas por modelos de regresión de ecuaciones de estimación generalizadas (GEE), controlando por las variables de confusión y/o modificadoras de efecto. Resultados: Se analizaron 511 espirometrías que cumplían criterios ATS/ERS (2-7 por cada niño). Se encontraron asociaciones significativas entre el MP2.5 de: lag12 máximo (FEV1 β-0.75 ml CI95% -1.5 -0.04; CVF β-1.90 ml CI95% -2.8 -1.01), lag4 promedio y máximo (CVF β-2.42 ml CI95% -4.7 -0.1 y CVF β-1.74 ml CI95% -2.7 -0.8, respectivamente), lag24 máximo (CVF β-2.01 ml CI95% -2.9 -1.03; PEF β-2.93 ml CI95% -5.7 -0.1) y lag48 máximo (CVF β-1.94 ml CI95% -2.8 -1.0; PEF β-2.77 ml CI95% -5.4 -0.1). Al ajustar por edad, sexo, peso, temperatura ambiental y velocidad del viento se mantuvo la asociación para los lag12, 24 y 48 y la CVF. Las concentraciones interiores de MP2.5 variaron entre 12,53 μg/m3 y 72,37 μg/m3, las exteriores entre 11,86 μg/m3 y 181,73 μg/m3 para verano. Otoño 24,06 μg/m3 a 80,22 μg/m3 en interiores y14,06 μg/m3 a 58,44 μg/m3 en exteriores. En invierno las concentraciones interiores variaron entre 21,85 μg/m3 y 110,53 μg/m3 y 21,38 μg/m3 y 93,07 μg/m3 en exteriores. La relación estacional I/E fue 0,22 a 0,28; 0,38 a 0,92 y 0,89 a 1,28, respectivamente. La composición y distribución de metales/metaloides al interior y exteriores fue altamente correlacionada (sala-patio, oficina-patio y oficina-sala fue r=0,98, r=0,98 y r=0,99). Los más frecuentes en interiores fueron Ca> S> Si> Cl> Na> Al> Fe> K> Mg> Ti> Cu> Zn> y Cr siendo entre 0,4 a 4 veces superior que los determinados al exterior. Conclusiones: Este es el primer estudio prospectivo donde se evalúa la asociación entre la exposición a MP2.5 y efectos en la función pulmonar de escolares que viven próximos a una playa masivamente contaminada con relaves mineros. Se observó una disminución en la capacidad vital forzada para los rezagos de 12 a 48 horas posterior a la exposición al MP2.5, el cual podría estar potenciado por la presencia de alto contenido de metales pesados en los microambientes escolares donde ellos pasan la mayor parte del tiempo, muchos de ellos con conocidos efectos tóxicos a nivel del organismo