Collection and Regeneration of Biodiesel Exhaust Particles for Off-Line Inhalation Toxicology Studies

VAISHALI SHARMA (1), Naomi K Fukagawa (2), Britt Holmén (1)

(1) School of Engineering, (2) College of Medicine, University of Vermont

     Abstract Number: 785
     Last modified: May 14, 2010

Abstract
The adverse health effects of diesel emissions have received increasing attention over the past few years. Previous studies have reported that diesel exhaust particles may induce a variety of health conditions including lung cancer, asthma, and other cardiovascular ailments. Recent toxicology studies have shown that nanoparticles (Dp < 50 nm) play an important role in determining the health effects of inhaled aerosols. Thus, it is desirable to deliver diesel exhaust nanoparticles for animal inhalation studies. Often, however, approved animal handling facilities do not have a directly available source of diesel particles. This research examines the possibility of off-line re-generation of diesel exhaust particulate via a two-stage process. In stage one, diesel exhaust particles (DEP) are collected from a laboratory test engine. In stage two, the collected DEP are aerosolized via a nanoparticle electrospray system for direct delivery to animals.

An impinger collected raw exhaust particulate (diesel or biodiesel) from the exhaust of a light-duty 1.9Liter, 4-cylinder diesel engine (Armfield CM12) into ethanol. Particle number distributions during engine operation were measured after dilution with clean laboratory air using an SMPS (6 to 250 nm). Subsequently, the impinger suspension was aerosolized using an electrospray system designed for this purpose. The electrospray droplets are dried and diluted to achieve target diesel particle concentration for animal exposure experiments. Initial results show similar particle number distributions from electrospray generation of diesel exhaust particles collected in ethanol impinger to that obtained for raw exhaust. The parameters affecting the resulting particle size distribution and particle composition will be further discussed.