Publications

Perspectives 3 is the third of a series produced by HEI to describe and interpret results from HEI and other research bearing on important and timely issues for a broad audience interested in environmental health. Perspectives 3 focuses on the health effects of ambient ultrafine particles (UFPs) and was developed under the guidance of a special HEI Review Panel. It examines the contribution of motor vehicles within the broader context of the multiple sources of ambient UFPs and explores the evidence from experimental studies in animals and in humans, as well as observational epidemiologic studies of people exposed to UFPs in the environment. It also identifies some of the broader lessons about both the specific health effects associated with exposure to UFPs and possible directions for future studies that could enhance our understanding of emissions, exposures, and effects of UFPs.

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 describes the first-ever multicity study to estimate the effect of short-term exposures to particulate matter (PM₁₀) and to ozone on mortality in nine Latin American cities. Led by Dr. Isabelle Romieu in Mexico, in collaboration with Dr. Nelson Gouveia in Brazil and Dr. Luis Cifuentes in Chile, the researchers evaluated mortality from all causes and in different age groups, using a common analytic framework. They analyzed mortality in each city and the region as a whole, and explored two pollutant models in individual cities. They also used two meta-analytic statistical techniques to further analyze the effects from individual cities.

This report describes a study to explore the role that specific chemical constituents of particulate air pollution may have played in effects on daily mortality observed after the 1990 Hong Kong restriction on sulfur in fuels. The study was part of HEI's Outcomes Research program, which aims to assess the health impacts of actions taken to improve air quality. Dr. Chit-Ming Wong of the University of Hong Kong and his team also developed methods to estimate the impacts on life expectancy of the 1990 sulfur restriction.

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.

Contents: Effects of Exposure to Diesel Exhaust Particles in Persons with Asthma and Allergy; Workshop Brings Experts Together: Atmospheric Chemists and Health Effects Scientists Meet at HEI to Discuss Common Goals; Symposium Sheds Light on Air Toxics Hot Spots; Wood Stove Changeout Program Brings Some Improvements in Health, Air Quality; Three New HEI Studies Launched: Ozone Exposure and Inflammatory Cells / PM Exposure and Heart Rhythm / Impact of Exposure in Early Life; ACES Reaches Important Milestones; New Investigator

This report describes a study that evaluated whether exposure to fine or nano-titanium dioxide (TiO₂) particles may affect cardiovascular endpoints, in particular endothelium-dependent vascular dilation. Dr. Nurkiewicz and colleagues exposed rats via inhalation to 0.5 to 20 mg/m³ TiO₂ for up to 12 hours and evaluated them for vascular dilation and for markers of oxidative stress, coagulation, and inflammation. This study was funded under the Walter A. Rosenblith New Investigator Award.   

This report describes a study that tested whether an air toxics "hot spot" existed in Camden, NJ. Dr. Lioy and colleagues evaluated ambient and personal exposures of nonsmoking residents to PM_2.5, VOCs, aldehydes, and PAHs in two neighborhoods in Camden, NJ, one of which was hypothesized to be a regional air toxics "hot spot." The investigators compared concentrations of air pollutants in the two neighborhoods with each other and then with concentrations at other locations in the United States. They also assessed the effects of seasonality, contributions from mobile sources, and spatial variability.

This report evaluates airway inflammatory responses and expression of the enzyme neprilysin in response to diesel exhaust particle exposure. Dr. Wong and colleagues hypothesized that components of diesel exhaust decrease neprilysin levels in airways, leading to airway function disorders and heightened responses to diesel exhaust. They exposed normal mice, mice genetically deficient in neprilysin, human subjects, and human airway epithelial cells to diesel exhaust particles and measured airway inflammation, neprilysin expression, and any unique responses in neprilysin-deficient mice.