The response of lung epithelium to well characterised fine particles

• Published in: Life sciences (1973) Vol. 62; no. 19; pp. 1789 - 1799
• Main Authors: Murphy, Samantha A., Bérubé, Kelly A., Pooley, Frederick D., Richards, Roy J.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 1998
• Subjects: Air Pollutants - adverse effects; Animals; Biomarkers; carbon; Carbon - adverse effects; Carbon - pharmacology; Cell Membrane Permeability - drug effects; diesel exhaust particles; Epithelium - drug effects; Epithelium - physiology; inflammation; Inflammation - chemically induced; Lung - drug effects; Lung - physiology; lung epithelium; lung permeability; Male; Neutrophils - drug effects; Organ Size - drug effects; Particle Size; Rats; Rats, Sprague-Dawley; Surface-Active Agents - metabolism; ultrafine particles; lung permeability; lung epithelium; diesel exhaust particles; inflammation; ultrafine particles; carbon
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/S0024-3205(98)00141-6

Diesel particles form a large component of the fine particle fraction (PM10) in urban air in the UK. During pollution episodes small increases in PM10 have been linked to detrimental health effects. The comparative toxicological effects of diesel exhaust and other well-characterised particles (carbon black, amorphous and crystalline silica) on rat respiratory epithelium were investigated in the present study. The effects of small masses of particles (1 mg) delivered by intratracheal instillation were monitored by changes in components of lavage fluid. Respirable, crystalline quartz, produced significant increases in lung permeability, persistent surface inflammation, progressive increases in pulmonary surfactant and activities of epithelial marker enzymes up to 12 weeks after primary exposure. Ultrafine amorphous silica did not induce progressive effects but it promoted initial epithelial damage with permeability changes and these regressed with time after exposure. By contrast, ultrafine fine carbon black had little, if any, effect on lung permeability, epithelial markers or inflammation, despite being given at a dose which readily translocated the epithelium and which has been reported to induce inflammation. Similarly, diesel exhaust particles produced only minimal changes in lavage components, although they were smaller individual particles and differed in surface chemistry from carbon black. It is concluded that diesel exhaust particles are less damaging to respiratory epithelium than silicon dioxide and that the surface chemistry of a particle is more important than ultrafine size in explaining its biological reactivity.