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. / 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.
| Identifer | oai:union.ndltd.org:TDX_UAB/oai:www.tdx.cat:10803/333059 |
| Date | 16 December 2015 |
| Creators | Cáceres Lillo, Dante Daniel |
| Contributors | Martín Mateo, Miguel, Universitat Autònoma de Barcelona. Departament de Pediatria, d'Obstetrícia i Ginecologia i de Medicina Preventiva |
| Publisher | Universitat Autònoma de Barcelona |
| Source Sets | Universitat Autònoma de Barcelona |
| Language | Spanish |
| Detected Language | Spanish |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | 180 p., application/pdf |
| Source | TDX (Tesis Doctorals en Xarxa) |
| Rights | L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-nd/3.0/es/, info:eu-repo/semantics/openAccess |
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