Research Reports

This report describes a study that analyzed the relationships between reductions in pollutants from power plants and fine particulate matter (PM_2.5) concentrations in the eastern United States between 1999 and 2005. Dr. Richard D. Morgenstern of Resources for the Future and colleagues used a novel data-driven source-receptor model to explore the statistical relationships between source emissions of sulfur dioxide (SO₂) and nitrogen oxides and monitored concentrations of PM_2.5. They performed various external comparisons of their models, and compared the reductions to an estimated counterfactual scenario in which no mandated reductions in SO₂ occurred.

This report provides the first systematic look at the health effects of exposures to emissions from a new-technology heavy-duty diesel engine. Included in this report are results obtained in rats and mice exposed for 1 and 3 months (and some results in rats at 12 months) to exhaust from a 2007-compliant diesel engine with aftertreatment to reduce particulate matter concentrations. Part 1 describes the core inhalation study by Drs. Jake McDonald and Joe Mauderly of the Lovelace Respiratory Research Institute, with results on general organ toxicity, lung histopathology, pulmonary function, and markers of inflammation and oxidative stress in blood and lung lavage fluid. Parts 2 and 3 describe studies by Drs. Jeffrey Bemis of Litron Laboratories and Lance Hallberg of the University of Texas Medical Branch, respectively, assessing genotoxic endpoints in the exposed rodents. Part 4 describes a study of vascular markers by Daniel Conklin of the University of Louisville. The Preface to this report contains background information about the planning and designing of the study, including decisions regarding the diesel exhaust dilutions and the choice of rodent strains.

This report describes a study to investigate the relationships among daily variations in air pollution in Ho Chi Minh City (HCMC), Vietnam, hospital admissions for acute lower respiratory infections in children under age 5, and poverty. The study was part of HEI's Public Health and Air Pollution in Asia (PAPA) program and is the first study of air quality and health to be performed in Vietnam. The team of investigators, led by Drs. Le Truong Giang, Long Ngo, and Sumi Mehta, collected daily pollutant data for PM₁₀, sulfur dioxide, nitrogen dioxide, and ozone at multiple locations throughout the city and obtained admissions data from the two pediatric hospitals in HCMC. They then performed statistical analysis on the data using Poisson time-series and case–crossover methods.

This report describes a study evaluating the effects of exposure to diesel exhaust (DE) and nitrogen dioxide (NO₂) on the lower airways and blood of allergic asthmatic participants. The study by Dr. Riedl and colleagues was funded as part of HEI's research program looking at diesel exhaust and other particle exposures and allergic response. The participants were exposed in random order to 100 µg/m³ diesel exhaust or 0.35 ppm nitrogen dioxide for 2 hours, with or without an allergen inhalation challenge. The investigators measured multiple physiologic and pulmonary function endpoints, including specific airway resistance, oxygen saturation, bronchial reactivity, and inflammatory and immunologic endpoints.