UBC Faculty Research and Publications

Air Pollution and Retained Particles in the Lung Brauer, Michael; Avila-Casado, Carmen; Fortoul, Teresa I.; Vedal, Sverre; Stevens, Bonnie; Churg, Andrew

Abstract

Epidemiologic evidence associates particulate air pollution with cardiopulmonary morbidity and mortality. The biological mechanisms underlying these associations and the relationship between ambient levels and retained particles in the lung remain uncertain. We examined the parenchymal particle content of 11 autopsy lungs from never-smoking female residents of Mexico City, a region with high ambient particle levels [3-year mean PM₁₀ (particulate matter ≤ 10 μm in aerodynamic diameter)= 66 μg/m³], and 11 control residents of Vancouver, British Columbia, Canada, a region with relatively low levels (3-year mean PM₁₀ = 14 μg/m³). Autopsy lungs were dissolved in bleach and particles were identified and counted by analytical electron microscopy. Total particle concentrations in the Mexico City lungs were significantly higher [geometric mean = 2,055 (geometric SD = 3.9) × 10⁶ particles/g dry lung vs. 279 (1.8) × 10⁶ particles/g dry lung] than in lungs from Vancouver residents. Lungs from Mexico City contained numerous chain aggregated masses of ultrafine carbonaceous spheres, some of which contained sulfur, and aggregates of ultrafine aluminum silicate. These aggregates made up an average of 25% of the total particles by count in the lungs from Mexico City, but were only rarely seen in lungs from Vancouver. These observations indicate for the first time that residence in a region with high levels of ambient particles results in pulmonary retention of large quantities of fine and ultrafine particle aggregates, some of which appear to be combustion products.

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Attribution-NonCommercial-NoDerivs 2.5 Canada