Dissociation of hexavalent chromium from sanded paint particles into a simulated lung fluid /

by Lange, Steven Harold

Title of Thesis: Dissociation of Hexavalent Chromium from Sanded Paint Particles into a Simulated Lung Fluid Steven Harold Lange, Capt, USAF, BSC Master of Science in Public Health, 2006 Thesis Directed By: Peter T. LaPuma, Lt Col, USAF, BSC Assistant Professor Department of Preventive Medicine and Biometrics Chromate-containing paint coatings are the primary means of protecting an aircraft surface from corrosion in the US military. Studies clearly link chromate exposure to human lung cancer. However, the few studies of the painting industry suggest that chromate exposure from paint particles does not increase the risk of lung cancer. Even fewer studies have evaluated sanding of chromate containing paint layers, and data suggests that sanders have an increased risk of lung cancer. A 6-stage cascade impactor was used to imitate particle deposition onto a layer of lung fluid. The lung fluid was simulated with a porcine based mucin. Sanded particles were collected based on particle size into the impactor’s six petri dishes, which contained lung fluid. After 24 hours, the fraction of chromate that dissolved into the lung fluid generally ranged from 60-90% for strontium chromate based paints and 10-50% for barium chromate based paints In water and solvent based strontium chromate paints, there was little difference between sanded and freshly sprayed paint particles. But for polyurethane and barium chromate based paints, sanded particles dissociated significantly more chromate than paint particles. iii Dissociation of Hexavalent Chromium from Sanded Paint Particles into a Simulated Lung Fluid By Steven Harold Lange Thesis submitted to the Faculty of the Department of Preventive Medicine and Biometrics Graduate Program of the Uniformed Services University of the Health Sciences in partial fulfillment of the requirements for the degree of Master of Science in Public Health 2006 iv