During the course of 1‐h/d, 5‐dlwk exposure to submicrometer sulfuric acid mist at 250 μg/m3, rabbits were exposed to a radioactively tagged polystyrene latex tracer aerosol to assess clearance from the alveolar region during the period 2–14 d after tracer exposure. The latex was administered on d 1, 57, and 240 following the start of the H2SO4exposures. Early alveolar clearance was found to be accelerated during the first test, and this acceleration was maintained throughout the 8‐mo monitoring period.