Ambient Atmospheric Particles in the Airways of Human Lungs

Abstract

Epidemiologic studies linking particulate matter (PM) air pollution and adverse respiratory and cardiovascular effects have focused attention on the interactions of PM and lung cells. Information on the types, numbers, composition, sizes, and distribution of ambient particles in the airways is potentially useful for correlations with pathological and/or physiological changes, but relatively little is known about the extent to which ambient particles actually enter airway epithelial cells and are retained in airway walls and even less information is available about correlations with pathologic changes. Since many ambient particles are colorless and/or well below the level of resolution of light microscopy, definitive evaluation of particle burden in the airway wall requires analytical electron microscopy. Studies from the authors' laboratory suggest that in Vancouver, a city with relatively low PM levels, particle loads in the airway mucosa are nonetheless numerically substantial, typically in the range of 107