Influence of Community Air Pollution on the Lungs of Mice. Part Ii: Image Analysis Quantitation of Lung Elastin

Abstract

AbstractTwo groups of 330 male Swiss-Webster mice were equally divided, with each exposed continuously to the outdoor air in central Los Angeles (LA) and Santa Barbara (SB). Nearby monitoring stations provided data on nitrogen dioxide (Nod, ozone (O3, sulfur dioxide, carbon monoxide, hydrocarbons, and particulates. The left lungs of all mice were perfusion inflated with 70% buffered formalin at 25 cm water pressure, and 6–μm paraffin-embedded lung sections were stained with aldehyde fuchsin for elastic fibers. Quantitative image analysis of the elastin and alveolar walls was carried out. Over the 43-day test period in Los Angeles, there were 21 exceedings of the state O3 standard, but only 2 for Santa Barbara. The mean value for the 1-h average O3 level in LA during the 43 days was 0.11 ppm, versus 0.03 ppm for Santa Barbara. The mean NO2 level in LA was four times higher than that for Santa Barbara, 0.12 versus 0.03 ppm. The levels recorded for other pollutants (carbon monoxide, NO2, sulfur dioxide, part...