Publications

This report describes semiparametric methods for epidemiologic investigations of the short-term effects of air pollution on health, intended specifically to improve the reliability of point estimates and confidence intervals. Dr. James Robins of the Harvard School of Public Health and colleagues developed the new methods, used simulations to compare them with other methods, and applied them to a large epidemiologic data set from the National Morbidity, Mortality, and Air Pollution Study (NMMAPS) to assess their effectiveness. The report is accompanied by a short editorial to assist the reader in understanding this study and its contributions to epidemiologic methods for air pollution.

This report describes the results of a study of long-term effects of PM components in the American Cancer Society's Cancer Prevention Study II cohort; a time-series study of short-term effects of PM components on cardiovascular and other diseases in people living in 150 U.S. cities; and two toxicologic studies in animals exposed by inhalation to concentrated ambient particles, and in animals and human cells exposed to particles collected on filters from five different airsheds across the United States. This report, along with Research Report 178 (Vedal et al.), is one of HEI's National Particle Component Toxicity (NPACT) studies, which describe the most systematic multidisciplinary studies to date to investigate the health effects of PM components in humans and animal models at locations across the United States where the effects of PM sources and components may differ. The report includes a Commentary and a Synthesis by the NPACT Review Panel.

This report revisits an earlier study of the air pollution and health impacts of a coal ban in Dublin, Ireland, and then extends the analysis to coal bans in 11 additional Irish cities. Dr. Douglas W. Dockery of the Harvard School of Public Health and colleagues evaluated changes in black smoke and sulfur dioxide concentrations for the 5 years before and after the coal bans and examined how those changes related to mortality and hospitalization rates in the counties affected by the bans, as compared with other counties where coal bans were not implemented. They also included in their analysis other trends in health and social factors that were occurring at the same time.

This newsletter reports on an expert panel named to review diesel epidemiology studies, two HEI Asia workshops on the global health impact of air pollution, and a meeting of HEI's Research Committee and sponsors reviewing progress and priorities, as well as HEI in the news.

This report describes a study in which a nano aerosol mass spectrometer (NAMS) was used to study composition of nanoparticles in real time near a major roadway intersection. Dr. Murray V. Johnston of the University of Delaware, Newark, and colleagues conducted a field test in Wilmington, Delaware, to evaluate performance of the instrument in a real-world setting and to assess whether it could aid in identifying the major source contributions to nanoparticle spikes and background levels, including distinguishing diesel from gasoline vehicles.

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.

This report contains studies in Chennai and Delhi led by Dr. Kalpana Balakrishnan and Dr. Uma Rajarathnam, respectively. These time-series studies of air pollution and mortality in India were funded under HEI's PAPA Program to provide information to inform regulatory and other decisions that would be relevant to local populations, with the added goal of supporting scientific capacity building in the region.

This report describes research funded under HEI's Air Toxics Hot Spot program. Dr. Eric Fujita and colleagues characterized concentrations of mobile-source air toxics (MSATs) and other pollutants in potential Los Angeles County pollution hot spots, including on urban highways with a varying mix of gasoline- and diesel-powered traffic and sites at various distances from the highways and close to other roads.

This report explores how land-use regression and source-apportionment techniques can be used to characterize individual-level exposure to both indoor and outdoor air pollution sources. Dr. Levy and colleagues utilized health and air monitoring data from an ongoing prospective cohort study on childhood asthma in Boston, Massachusetts to model variability in outdoor and indoor residential air pollution, identify potential sources, and evaluate the effectiveness of various indoor exposure surrogates for predicting childhood asthma development.

This report describes the first set of coordinated time-series studies ever undertaken in Asian cities: four time-series studies of the health effects of air pollution in Bangkok, Hong Kong, Shanghai, and Wuhan. These studies were intended to help bridge the gaps between studies conducted in different locations around the globe.

Communication 15, Proceedings of an HEI Workshop on Further Research to Assess the Health Impacts of Actions Taken to Improve Air Quality, summarizes the findings of a workshop held in December 2009 that reviewed the current state of research to evaluate the impact of air quality interventions (also known as accountability or air quality outcomes research).

This report describes a study by Dr. Thomas Cahill and colleagues to create and evaluate a new method to measure acrolein and other volatile carbonyls present at low concentrations in ambient air. Acrolein is an important aldehyde that is very difficult to measure accurately, so developing better methods for measuring levels and exposure is critical to better risk assessment for the chemical. The investigators developed a sampler that traps acrolein using sodium bisulfite in an aqueous medium.

This report is the latest in HEI's program of studies to assess the health impacts of air quality actions. Research Report 148 describes a study to evaluate the effect of a short-term, temporary intervention to reduce traffic congestion during the 1996 Summer Olympic Games in Atlanta, Georgia. A previous study had shown a decrease in acute care visits for pediatric asthma and a concomitant decrease in concentrations of ozone, particulate matter, and carbon monoxide.

This report describes a study to investigate the role of two subpopulations of T cells in the airway response to inhaled acrolein, a toxic pollutant in ambient air, which US EPA's National Air Toxics Assessment has identified as having broad effects. Dr. Michael Borchers and colleagues measured inflammation and injury in response to acrolein in the lungs of mice that are genetically deficient in the specific T-cell subpopulations. He also measured changes in gene expression in the T-cell subpopulations after acrolein exposure. This study was funded under the Walter A.

This report describes a unique collaboration among investigators from Europe, the United States, and Canada using existing data from three geographic areas and supported by HEI in collaboration with the European Commission. APHENA offered a large and diverse data set with which to address methodological as well as scientific issues about the relationships between PM₁₀, ozone, and mortality and morbidity that were the subject of lively debates at the time the project was launched. 

This report describes a study to evaluate genotoxic effects of exposure to 1,3-butadiene and its metabolites. 1,3-Butadiene is classified as a human carcinogen via inhalation, but risk assessment is complicated due to differences in metabolism between mice and rats and between males and females. Dr. Walker and colleagues studied mutagenicity in rats and mice of both genders, with a focus on evaluating stereoisomers of 1,3-butadiene metabolites and low exposure concentrations.

This report describes a recent analysis of the original ACS cohort, a large ongoing prospective study of mortality in adults that started in 1982 and has played a central role in the setting of National Ambient Air Quality Standards for fine particulate matter pollution in the U.S. as well as assessments of benefits from PM reduction worldwide. The new study describes for the first time work by Dr.

Research Report 139 describes a study in the Netherlands using data from the ongoing Netherlands Cohort Study (NLCS) on diet and cancer. The study is one of the first to systematically assess longer term exposure and mortality in a well characterized European population; it followed a pilot study of 5000 adults randomly selected from the NLCS cohort conducted by the same team of investigators. For the current study, Dr.

Research Report 138, Health Effects of Real-World Exposure to Diesel Exhaust in Persons with Asthma, is one part of HEI's larger program on the role of particles in exacerbating asthma and other allergic diseases. This report describes a study to evaluate how inhaling air with a high concentration of diesel exhaust from vehicular traffic while walking on a busy street in Central London might affect people who had either mild or moderate asthma. Dr.

Research Report 135 describes a study to determine whether the biologic response to inhaled ultrafine particles depends on particle composition. Neonatal and young adult rats were exposed to laboratory-generated ultrafine metal particles, either alone or in combination with soot, and their lungs examined for oxidative stress, inflammation, and injury.

Research Report 134 describes a study that evaluated whether there was an association between particles detectable in the airways of healthy children and a) estimates of local, traffic-derived PM₁₀ at the children's home addresses or b) their lung function. Dr. Jonathan Grigg and colleagues recruited 116 healthy children aged 8 to 15 years who lived in Leicester, UK. In addition to modeling each child's exposure, the investigators measured lung function and evaluated induced sputum for particles in airway macrophages and markers of inflammation.

The RIOPA project comprised three studies, one funded by the Mickey Leland National Urban Air Toxics Research Center (NUATRC) and two funded by HEI, that investigated seasonal concentrations of 16 VOCs, 10 carbonyls, and PM_2.5 in homes in Los Angeles CA, Houston TX, and Elizabeth NJ. The project was jointly funded and reviewed by a Special Review Panel of the two organizations. It generated a rich database on concentrations of air toxics and PM2.5 in the personal breathing zone of 100 adults in each city as well as inside and outside their homes.

This study by Dr. Elizabeth Delzell and colleagues is the first major update of the most extensive human study to date of potential carcinogenic effects of 1,3-butadiene (BD). The earlier study investigated mortality among the largest occupational group exposed to BD: 18,000 men employed in the styrene-butadiene rubber (SBR) industry between 1944 and 1991. In the current study, these workers were followed for an additional 7 years and the effects of exposure to other compounds were evaluated.

Dr. Koutrakis and his colleagues assessed the correlations between personal exposure to PM_2.5 and gaseous copollutants and compare these measurements with those taken at central-site monitors. Three groups of possibly susceptible individuals (children, seniors, and individuals with chronic obstructive pulmonary disease) were recruited in two cities (Boston and Baltimore) in two seasons (summer and winter).

In Part IV of the Morbidity, Mortality, and Air Pollution Study (NMMAPS), Dr Francesca Dominici and colleagues at Johns Hopkins Bloomberg School of Public Health addressed an important question resulting from the combined analysis of air pollution effects on mortality and on hospital admissions. Is the underlying true effect per unit PM₁₀ on mortality (the mortality slope) of the same magnitude as the effect per unit PM₁₀ on hospitalizations (the hospitalization slope) in a given city?

This report contains two studies, by Drs. Annette Peters and Douglas Dockery. Dr. Peters and her colleagues evaluated the association between nonfatal myocardial infarction (MI) and exposure to particulate matter just prior to the event. She asked 691 patients in hospitals in Augsburg, Germany who survived an MI to provide hourly details about their activities 4 days before MI onset. The investigators used a case-crossover analysis to determine whether exposure to pollutants was associated with onset of MI. Dr. Dockery and colleagues assessed the correlation between short-term increases in ambient concentrations of particulate matter and the risk of possibly life-threatening arrhythmias in patients with implanted cardioverter defibrillators (ICDs). The investigators studied 195 patients from Boston, MA who had either single or dual-chamber ICD's and used logistic regression models to determine whether exposure to air pollutants was associated with arrhythmias.

Dr. Witten and colleagues investigated the inflammatory effects of diesel exhaust exposure on rat airways. The investigators focused on the role of neurogenic inflammation, an inflammatory response defined by the release of neuropeptides, such as substance P (SP), from sensory nerve fibers known as C fibers located within the lung tissue. Neurogenic inflammation has been implicated in responses to inhaled irritants such as ozone and cigarette smoke and has been implied to play a role in asthma.

This report describes a study funded under the Walter A. Rosenblith New Investigator Award. Dr Francesca Dominici and colleagues at Johns Hopkins University developed more flexible methods and statistical models for the National Morbidity, Mortality, and Air Pollution Study database.

Dr Alison S Geyh and colleagues at Johns Hopkins University evaluated the personal and microenvironmental aerosol speciation sampler (PMASS) prototype developed by Dr. Susanne Hering with HEI funding (HEI Research Report 114). The precision and accuracy of the prototype, which measures PM_2.5 mass, elemental and organic carbon, sulfate, and nitrate, was evaluated in two locations with different PM composition. Baltimore, Maryland (outdoors), and Fresno, California (indoors). Geyh and colleagues set a target of 10% precision and 10% accuracy for all species measured.

Dr. Jack Harkema and colleagues at Michigan State University conducted a 2-year study with rats to evaluate the short-term effects of inhaling concentrated ambient particles derived from the air in an area of Detroit, Michigan that has a high incidence of childhood asthma. The investigators used two animal models, BN rats that were sensitized with ovalbumin to induce some features of asthma, and F344 rats pretreated with endotoxin to have some features of mild bronchitis. Animals were exposed for 10 hours/day for 1 day or for 4 or 5 consecutive days.

A Special Report by the HEI International Scientific Oversight Committee of HEI Public Health and Air Pollution in Asia (PAPA) Program (a program of the Clean Air Initiative for Asian Cities). This first publication to come from HEI's PAPA Program was undertaken to help inform the Clean Air Initiative for Asian Cities. This special report has identified and summarized more than 135 studies of air pollution and health conducted across Asia. In addition, it critically reviews for the first time a key subset of these studies: 28 studies of daily mortality. The report is a valuable resource for policy makers in Asia and beyond.

Dr. Laskin and her colleagues at the Environmental and Occupational Health Sciences Institute at Rutgers University tested the hypothesis that oxidants in ambient air, such as hydrogen peroxide, may be transported by fine particulate matter into the lungs and thus contribute to lung tissue injury. The investigators used ammonium sulfate particles because of their prevalence in the ambient air of the eastern United States and their reportedly low toxicity in animals and humans.

Dr. Henry Gong Jr and his colleagues at the Los Amigos Research and Education Institute used a Harvard ambient particle concentrator to assess the effects of exposure to concentrated ambient particles (CAPs) on healthy and asthmatic people. 12 healthy individuals and 12 individuals with mild asthma were exposed to either filtered air or CAPs with a maximum exposure level of 200 µg/m³ for two hours while exercising intermittently on a stationary bicycle.

Dr. Albertini and colleges organized a group of researchers from the United States, Czech Republic, The Netherlands, and the United Kingdom to determine whether biomarkers in the blood and urine of workers exposed to butadiene in occupational settings correlated with their personal exposure. Samples were collected from male workers employed either in a plant that used butadiene and styrene to produce rubber polymer in Prague. They also collected blood and urine from male administrative workers at the plant who had no direct occupational exposure to butadiene and served as control subjects.

Dr. Qingshan Qu and colleagues at the New York University School of Medicine recruited 181 healthy workers in several factories in the Tianjin region of China. These subjects formed part of a cohort of thousands identified by the US National Cancer Institute (NCI) and the China Academy of Preventive Medicine for a study to evaluate tumor incidence in benzene exposed workers (NCI/China study).

Communication 10 contains proceedings of a workshop held in Baltimore, MD, December 4–6 2002. The workshop sought to address the search for a "Diesel Signature": Do We Have a Diesel Signature? Where Do We Go From Here? Communication 10 includes a workshop summary and reports from speakers on: Health Studies of Diesel Particulate Matter; Future Trends of Diesel Emissions; Diesel and Gasoline Particle Characteristics; Approaches to Particle Characterization; Diesel Source Signature Studies; Emissions and Air Quality Studies; Data Analysis Approaches.

Drs Turteltaub and Mani at Lawrence Livermore National Laboratory investigated benzene metabolism in rodents over a large dose range that encompassed concentrations close to those of human ambient exposure. Understanding benzene metabolism at low exposure levels is critical to benzene assessment to determine the shape of the dose-response curve at low concentrations.The investigators administered radioactive benzene to mice and rats and subsequently analyzed bone marrow, liver, urine, and plasma from these animals.

Dr. Nadziejko and her colleagues at the New York University School of Medicine evaluated the effects of exposing healthy rats to concentrated ambient particles (CAPs) and changes in blood coagulation parameters. The investigators measured platelet number, blood cells counts, and levels of fibrinogen, thrombin-antithrombin complex, tissue plasminogen activator, plasminogen activator inhibitor, and factor VII of rats that were exposed to concentrated New York City particles and filtered air for 6 hours. Blood samples were obtained before and after exposure using an indwelling catheter.

Drs. Matanoski and Tao at Johns Hopkins University examined the relationship between styrene exposure and heart disease in workers in styrene-butadiene polymer manufacturing plants between 1943 and 1982. Workers who had died from ischemic heart disease were compared to a subgroup of all men employed in two styrene-butadiene polymer manufacturing plants during that time. Individual exposure histories were determined from job records, or constructed using a statistical method to estimate exposure when records were missing.