Research Program Area: Health & Exposure
Adverse respiratory effects are associated with PM10 exposure, although the attribute(s) of PM10 and biological mechanisms responsible are unclear. This study evaluated airway epithelial cell morphometry, macrophage function, breathing pattern, and ventilation in rats exposed for 4 hr/d, 4 d/wk for eight weeks to components of PM10 (ammonium sulfate, ammonium nitrate, and road dust) singly, in combinations, and in mixture including 0.20-ppm ozone (O3). There were no changes in goblet cells with any exposure. High and low concentrations of PM10 components, singly and combined with 0.2ppm O3, reduced Fc-mediated phagocytic activity, suggesting an additive effect. Particles alone decreased respiratory burst activity, suggesting that these PM10 components can inhibit macrophage function, although when O3 was included, respiratory burst activity increased. High concentrations of both sulfate and nitrate significantly increased airway permeability, but low concentrations and mixtures of particulates and O3 had inconsistent effects. Changes in breathing pattern and minute ventilation consistent with mild pulmonary irritation occurred with exposure to all particle types at the high, but not the low, concentration. Addition of O3 to the exposure mixture induced breathing pattern responses indicative of an O3 effect, while exposure to high concentration multi-component mixtures of PM10 compounds and O3 induced effects suggesting interaction between PM10 and O3.
Also see related report for contract A933-158 Published May 1993
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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