Pulmonary function responses in cats following long‐term exposure to diesel exhaust

Abstract
Long‐term inhalation studies were carried out to evaluate the toxic pulmonary effects of diesel engine emissions. Cats were exposed for over 2 years to whole, diluted diesel exhaust at levels expected to produce frank toxic effects. During the first 61 weeks of exposure, the cats received exhaust having a particulate level of 6 mg m−3. This was followed by a doubling of the exposure level from weeks 62 to 124 resulting in particulate levels of 12 mg m−3. No definitive pattern of pulmonary function response was observed following 61 weeks; however, a classic pattern of restrictive lung disease was found at 124 weeks. The significantly reduced lung volumes and diffusing capacity were indicative of a pulmonary interstitial response which was later verified by histopathology.