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| - Overview
- Core Director and members
- Keywords
- Research Progress
Overview
Under the leadership of Dr. Jonathan Samet, Professor and Chair of the Department of epidemiology and Dr. Patrick Breysse, Professor of Environmental Health Engineering, Research Core 1: Environmental Epidemiology and Exposure Assessment brings together a core of faculty to address the issues of characterizing the occurrence and causes of morbidity and mortality in Baltimore City, the surrounding region and in other high-risk populations. The diseases investigated by research members of this core include both cancer and non-cancer endpoints. Cancers include respiratory, prostate and breast cancer outcomes and the non-cancer diseases are focused upon neurologic, cardiovascular and respiratory diseases. Particulate and photochemical air pollution factors in combination with ozone exposure are investigated as well as lead intoxication, indoor air pollution, environmental asthma, environmental tobacco smoke and allergy in both adults and children. Since the tragic attacks of September 11, 2001, the expertise of this research core and its associated facility core laboratories have been called upon to address health outcomes in workers at the World Trade Center and Pentagon disaster sites. Core Director and Members
Dr. Jonathan Samet, Director and Chair
Department of Epidemiology
Johns Hopkins Bloomberg School of Public Health Dr. Patrick Breysse, Co-Director and Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Timothy Buckley, Associate Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Thomas Burke, Professor
Department of Health Policy and Management
Johns Hopkins Bloomberg School of Public Health Dr. Gregory Diette, Assistant Professor
Pulmonary, Johns Hopkins School of Medicine Dr. Francesca Dominici, Assistant Professor
Department of Biostatistics
Johns Hopkins Bloomberg School of Public Health Dr. Jean Ford, Associate Professor
Department of Epidemiology
Johns Hopkins Bloomberg School of Public Health Dr. Alison Geyh, Assistant Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Rolf Halden, Assistant Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Kathy Helzlsouer, Professor
Department of Epidemiology
Johns Hopkins Bloomberg School of Public Health Dr. Peter Lees, Associate Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Genevieve Matanoski, Professor
Department of Epidemiology
Johns Hopkins Bloomberg School of Public Health Dr. Craig Newshaffer, Associate Professor
Department of Epidemiology
Johns Hopkins Bloomberg School of Public Health Dr. John Ondov, Professor
Department of Chemistry
University of Maryland Dr. Kellogg Schwab, Assistant Professor
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health Dr. Scott Zeger, Professor
Department of Biostatistics
Johns Hopkins Bloomberg School of Public Health Key Words
Environmental epidemiology, biomarkers, exposure assessment Progress
Drs. Samet and Breysse are currently collaborating on the largest health survey ever conducted in the Kingdom of Saudi Arabia. The purpose of the study is to characterize the consequences for the health of the residents of Saudi Arabia of the 1990 - 91 Gulf War. The survey sampled from regions where the civilian populace would have been exposed to the smoke from the oil fires in Kuwait, to troop movements or other combat-related activity, to both smoke and troops, and to neither of these factors. The survey had three purposes: (1) to provide a general characterization of the health of Saudi citizens after the conflict; (2) to characterize the health consequences of exposures of the population as the basis for estimating past and future medical morbidity and attendant costs of the 1990-1991 Gulf War conflict, and (3) to identify conditions and individuals for the purpose of targeting medical monitoring towards those affected by the conflict. The Exposure and Health Survey (E&HS) included 20,000 participants, sampled in equal numbers from the four strata defined by smoke exposure and troop movement, based on information available from various source.
The multidisciplinary Center for Childhood Asthma in the Urban Environment, funded since 1998 successfully competed for another 5-year renewal in the fall of 2003. Core members Breysse, Buckley, Diette and Dominici are all collaborators in this Center. The CCAUE conducts epidemiologic and intervention trials of asthma in Baltimore City. Research within the Center involves collaboration between a number of other Research Cores and extensively uses Exposure Assessment Core Facility. A number of publications have been submitted from this work. (Eggleston et al. 2003; Breysse et al. 2003).
Since 1994, Drs. Samet and Zeger, and more recently Dr. Dominici, have been funded by the Health Effects Institute to conduct studies of particulate air pollution and mortality. The research program was initially intended to address key gaps in understanding of the effects of particulate air pollution, as the Environmental Protection Agency considered the primary National Ambient Air Quality Standard for particles. The initial focus was on a series of methodological topics that were of concern in the evidence base assembled for the review carried out by the Agency in 1994-1996 that led to the promulgation of a new standard for particulate matter in 1997. The team has since developed new, national models for characterizing the health effects of air pollution. In the National Morbidity, Mortality and Air Pollution Study, national databases were assembled on daily deaths and hospitalizations, air pollution levels, temperature, and city characteristics. Bayesian, hierarchical models were developed for mapping the effects of air pollution on daily mortality counts across the country and for aggregating the evidence to gain an overall picture of the risk posed by air pollution to the nation (Dominici et al. 2000; Samet et al. 2000; Dominici et al. 2001, submitted). Additionally, methods were developed for jointly analyzing data on morbidity and mortality and then applied to data from 14 cities (Dominici et al. 2001, submitted). The NMMAPS approach, now being extended into a web-based format, offers a useful model, not only for air pollution, but also for other environmental pollutants with widespread but varying exposure. This work has now been extended with receipt of new funding from the Health Effects Institute to bring together time-series data sets on air pollution and morbidity and mortality from Europe and North America for a combined analysis, from the NIEHS for development of statistical methodology for environmental epidemiology, and from the U.S. Environmental Protection Agency for using a Medicare cohort to address the long-term effects of air pollution. Additionally, funding has been received during the last year from the Environmental Protection Agency for national analyses directed at ozone and mortality. The project includes national-level analyses using an updated NMMAPS database and a meta-analysis of published studies.
Cancer research continues to be an important focus of Environmental Epidemiology and Exposure Assessment Research Core faculty. Dr. Helzlsouer has conducted studies of the association between persistent organochlorine compounds, in particular DDT and PCBs and the development of cancer (breast, prostate and in collaboration with Dr. Rothman at the National Cancer Institute, non-Hodgkin's lymphoma). Nested case-controls studies were conducted using the resources of two serum banks, CLUE I (N=25,802) and CLUE II (N=32,320), established in Washington County, Maryland in 1974 and 1989, respectively to examine the association between prediagnostic serum concentrations of DDE and PCBs and the development of cancer up to 20 years after blood donation. In addition, Dr. Helzlsouer in collaboration with Dr. Strickland (Gene-Environment Interaction and Disease Prevention Research Core) is currently investigating polymorphisms of many genes controlling metabolism of xenobiotic and endogenous compounds and DNA repair processes that are emerging as risk factors for a wide variety of cancers and other diseases. To date, an understanding of the risks associated with specific genes has come largely from studies of particular disease. It is critical to acquire population data to understand the effects of this genetic variation on overall health and longevity in the general population. We need studies that are more holistic in design and provide insights into the net effect on health of having specific genotypes. A population-based cohort study is being conducted to assess the broad impact on health of having common genetic variations in genes encoding for enzymes that: 1) Metabolize nutrients and hormones (Methyltetrahydrofolate reductase (MTHFR), Vitamin D receptor, cytochrome P450 17, CYP1B1, Catechol-O-methyltransferase; 2) Metabolize carcinogens (Alcohol Dehydrogenase, Glutathione-S-transferases, N-acetyl transferases, Nitric Oxide Synthase, CYP1A1 and CYP1B1, Epoxide Hydrolase; and 3) control DNA repair processes.
Dr. Matanoski continues to direct the operation and management of the District of Columbia Cancer Registry. These registries are important resources to Center investigators and have been used to evaluate the high cancer rates in Baltimore City. Cancer incidence and mortality rates were calculated by zip code to address neighborhood concerns about high rates of cancer, particularly those residents of zip codes with substantial industry.
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Research in the exposure assessment component of this core continues to expand covering a spectrum of activities related to the measurement and/or estimation of exposures to a wide variety of chemical and physical agents. Ongoing research in this core area is both autonomous and conducted in conjunction with other disciplines, particularly environmental epidemiology. Autonomous activities include development and validation of exposure assessment methods, development of appropriate exposure assessment tools for use in epidemiologic studies, and development of mechanistic descriptions of exposure processes. A considerable portion of the ongoing exposure assessment research is conducted in conjunction with epidemiologic and clinical studies to identify and quantify exposure-outcome relationships. These studies have been conducted in a wide range of venues, including specific urban and community-based research.
During the past year the Core has continued to focus on exposure assessment activities that develop intra and inter-Core interactions. A new project begun during the last year is an investigation of spatial determinants of organochlorine pesticide body burdens in a central Maryland community. The impetus of the project is the existence of a large former pesticide manufacturing facility that is a Superfund site and availability of large number of banked organochlorine biomarker measurements collected as a part of previously conducted cancer studies. This project involves interactions with Dr. Strickland in Gene-Environment Interaction and Disease Prevention Research Core and data previously collected by Dr. Helzlsouer. In addition, the Bioinformatics/Biostatistics Facility Core provides support for the spatial analysis.
Dr. Halden has developed analytical techniques to assess the biocide triclosan and its biotransformation products in environmental samples and breast milk using liquid chromatography/mass spectrometry and gas chromatography/mass spectrometry. This work extends the analytical capabilities of the Center and utilizes equipment in the Environmental Exposure and Health Assessment Facility Core
Drs. Breysse and Samet continue to collaborate on an extensive environmental tobacco smoke (ETS) project in South America. As a part of the project roughly 1000 airborne nicotine samples are being collected in public spaces and workplaces throughout South America. These samples are being analyzed by the Environmental Exposure and Health Assessment Facility Core. This project, which originally involved 7 countries has now been expanded to include eight additional countries. In addition, we are conducting a pilot study of airborne nicotine exposures in Korean restaurants in New York City. This research, which builds on the expertise, developed in order to assess ETS exposure in inner-city homes (part of the Center for Childhood Asthma in the Urban Environment). Dr. Samet has received funding from the Flight Attendants Medical Research Institute that is being used to develop a global protocol for assessing exposures of women and children to ETS. A protocol is under development for this three-year study.
With funding from the Electric Power Research Institute, Dr. Geyh is investigating the specific characteristics of particulate matter responsible for health effects demonstrated by a series of recent epidemiological studies of cardiovascular outcomes. Case-crossover analysis and personal exposure assessment are being conducted in Baltimore City to explore the relationship between exposure to particles and exacerbation of symptoms of heart failure in patients diagnosed with congestive heart failure. The patient population (N=130) has been recruited and monitoring is now completed. This 2-yr study is using the detailed particle data collected at the Baltimore PM Supersite. This project involves collaboration with other Core members (Dr. Samet and Ondov) as well as support from the Environmental Exposure and Health Assessment Facility and Bioinformatics/Biostatistics Facility Cores.
Investigations into worker health at both the World Trade Center and the Pentagon are continuing. The Pentagon project is funded by the Department of Defense and is intended to identify a cohort of potentially exposed workers for medical and epidemiologic follow-up. The During the last year the World Trade Center project has focused on developing a cohort of trades workers involved in the clean up of the site preparing to mail a large health and exposure survey. This work, funded by NIEHS and the School involves collaboration and interaction with three other NIEHS Centers including Columbia University, New York University, and University of Medicine and Dentistry of New Jersey EHS Centers, as well as the Mt. Sinai School of Medicine. These projects are both multidisciplinary and have been directly stimulated by interactions and funding within the Center.
In addition to the above, exposure assessment and collaborative activities associated with the Center for Childhood Asthma in the Urban Environment, the Baltimore Traffic Study are ongoing.
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A variety of risk assessment projects have been carried out and core members are engaged in many key risk assessment activities at the national level. Dr. Thomas Burke is assessing risk profiles at selected military facilities and he has also recently been funded by the Centers for Disease Control for an environmental tracking center. For air pollution, the magnitude of the risk to public health remains a key focus of research. Drs. Dominici, Samet and Zeger continue their work on methods to better characterize the effects of air pollution on health, including further use of large national data bases and needed statistical and epidemiological approaches to measure the loss of life associated with air pollution. (BACK TO TOP) |
