Table of Contents
Journal of Respiratory Medicine
Volume 2014 (2014), Article ID 797050, 9 pages
Clinical Study

Inhalation of Nebulized Diesel Particulate Matter: A Safety Trial in Healthy Humans

1School of Human Kinetics, Laurentian University, 935 Ramsey Lake Road, Greater Sudbury, ON, Canada P3E 2C6
2Medical Sciences Division, Northern Ontario School of Medicine, ON, Canada P3E 2C6

Received 15 May 2013; Revised 17 December 2013; Accepted 19 December 2013; Published 4 February 2014

Academic Editor: Dimitar Sajkov

Copyright © 2014 Sandra C. Dorman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Diesel particulate matter (DPM) has adverse health effects. Examining the underlying pathophysiological mechanisms would be facilitated by the introduction of an exposure method that is safe, portable, and cost-effective. The purpose of this study was to establish a novel method to study DPM exposure via nebulization and an inhalation dose that was safe, yet capable of eliciting an inflammatory response. Ten participants enrolled in this nonblinded, nonrandomized study. Subjects inhaled nebulized 0.9% saline and increasing doses of DPM suspended in 0.9% saline (75, 150, and 300 μg) in a sequential manner. FEV1 was measured repeatedly during the first 2 h after exposure and blood, oximetry, sputum, and heart rate were taken before, 2 h, and 24 h after inhalation challenge. DPM inhalation was well-tolerated at all doses. A decrease in FEV1 was observed after each inhalation challenge (including saline). Inhalation of 300 μg DPM produced a significantly different FEV1 response curve. An increase in particle inclusion-positive sputum macrophages for all DPM doses confirmed that the nebulized particles were reaching the lower airways. Serum GM-CSF was elevated after exposures to 150 and 300 μg DPM. No other inflammatory changes were detected. DPM inhalation via nebulizer is a safe method of delivering low doses of DPMs in healthy people.