Research on health effects of particulate matter (PM) has been a very active area in the last two decades. One plausible mechanism by which exposure to PM affects human health includes modification of autonomic endothelium function. Decreased endothelium activity causes heightened risks of cardiovascular disease. A human exposure chamber designed to conduct experiments to quantify diminished function of endothelium from short term exposure to PM is described. The chamber consists of two stages for containment and pre-treatment of PM and exposure of human subjects. Concentrations of CO, CO2, NO, NO2, O3, and PM2.5, are monitored and controlled in the exposure room. The PM used in the human exposure experiments was characterized chemically and morphologically. During January and February of 2009, chemical analysis of PM2.5 was done during inversion periods in Salt Lake City, UT. An Ambient Ion Monitor (AIM) was deployed to measure the concentrations of anions in both particulate and gas phases. The chemical data provided by AIM was complemented by measurements by the Department of Air Quality that included PM10, PM2.5, O3, NO, NO2, NH3 and CO. The goal of the study was to determine whether ammonia or nitric acid is the limiting reagent in formation of PM during inversions. Nitric acid is the limiting reagent. Concentrations of ammonia are an order of magnitude higher than nitric acid.



College and Department

Physical and Mathematical Sciences; Chemistry and Biochemistry



Date Submitted


Document Type





Human exposure, endothelial function, PM, bag, inversion, ammonium nitrate, Salt Lake Valley, air pollution, air quality standards