NASA Space Systems Enhance Public Health Science for Society
John A. Haynes and Robert Venezia
As one of the twelve areas of national priority for the National Aeronautics and Space Administration's (NASA's) Applied Sciences Program, the Public Health Program Element extends the benefits of increased knowledge and capabilities resulting from NASA research and development of Earth-Sun spacecraft observations, model predictive capabilities, and technology, into partners' decision support systems for public health, medical, and environmental health issues. Through the Public Health Program, NASA and partnering organizations have built a network that focuses on the relationships between NASA Earth observation systems, modeling systems, and partner-led decision support systems for epidemiologic surveillance in the areas of infectious disease, environmental health, and bioterrorism. [Figure 1]
The use of Earth observation technology, observations, and forecasts for health-related research is well established in the Earth science literature and is focused primarily on the identification of infectious disease vectors based on habitat characteristics. The potential of using Earth observations to enhance predictions of major health events, such as outbreaks of Rift Valley Fever and other arthropod-borne diseases, has been demonstrated with considerable accuracy on a regional scale (Linthicum et al. 1999). However, until recently, little use of the technology or science has been made in a systematic manner by public health policy-makers or practitioners to make health-related decisions, such as the allocation of public health resources or rapid response to outbreaks. NASA, the Centers for Disease Control and Prevention (CDC), and other partners are addressing this issue by integrating predictive information into epidemiologic surveillance systems based on environmental and other determinates of disease that are observable from the vantage point of low-Earth orbit (Beck, Lobitz and Wood 2000).
NASA collaborates with members of the professional public health community who are responsible for epidemiologic surveillance to understand and respond to factors in the environment that adversely affect the health of the American public. These factors include disease vectors, air and water contaminants, ambient temperature extremes, and ultraviolet radiation associated with public health problems. International health is included in the scope of the Program because it represents a national health concern through its potential effect on American public health, economics, and national security. To this end, NASA has connections with the Group on Earth Observations, the United States Group on Earth Observations, and the World Health Organization.
The decision support structure of the public health community is based partially upon health information provided by epidemiologic surveillance. According to the CDC, epidemiologic surveillance may be described as "the ongoing, systematic collection, analysis, interpretation, and dissemination of data regarding a health-related event for use in public health action to reduce morbidity and mortality and to improve health" (CDC 2001). As outlined by the CDC, the following primary attributes of a surveillance system combine to determine its usefulness for decision-makers:
A useful surveillance system enables the continual collection of observations for monitoring disease trends and outbreaks for a public health response. While these observations may be used for scientific investigations, surveillance systems are designed primarily to support decision makers, not to support research. In general, the incorporation of Earth-Sun science observations into measurement systems and models is intended to improve their accuracy with regard to spatial and temporal dimensions of the phenomena they represent. These improvements enhance the representative attribute of surveillance systems.
NASA, the CDC, and partners collaborate on plans to enhance the ability of surveillance systems to assimilate observations and predictions of weather, climate, and environmental risk factors to predict disease events. In surveillance terms, the goal for integrating Earth-Sun science and Public Health observations is to represent more accurately these environmental risk factors in terms of the populations potentially affected by them. The NASA collaboration on public health addresses four attributes of a reliable surveillance system listed above: simplicity, flexibility, acceptability, and timeliness. These four attributes of partner surveillance systems will be enhanced by ensuring interoperability of Earth-Sun system science measurements with other important public health functions identified in the evaluation, verification/validation, and benchmarking stages of the collaboration.
NASA partners with federal agencies and with regional and national organizations that have public health responsibilities as well as mandates to support public health practitioners. NASA's primary partners are the CDC, the National Institutes of Health, the U.S. Environmental Protection Agency, the Department of Health and Human Services, the National Oceanic and Atmospheric Administration, the Department of Defense (DOD), and the Department of Energy. As potential global climate change (both natural and human-induced) will have a major effect on public health through regional weather changes, air pollution levels, contamination pathways, and pollution transmission dynamics, NASA strongly supports the interagency programs on Climate Change Science and Technology.
NASA currently supports projects to demonstrate the capacity of Earth-Sun system research results to enhance five different decision support systems:
The National Environmental Public Health Tracking Network (EPHTN) is a decision support system owned and operated by the CDC. The system is designed to establish a national network of local, state, and federal public health agencies that tracks trends in priority chronic diseases. When the system is fully functional around the year 2009, the EPHTN will be a national early warning system for the rapid identification of health threats, such as toxic chemical releases. The EPHTN also will establish the long-term collection of information on harmful exposures to be used in future studies of new environment-disease correlations. Earth science results will provide new information on the environmental contribution to chronic disease and predictive value based on coupled Earth system-chronic disease models.
Under the collaboration on the EPHTN, NASA and the CDC are partners in linking environmental and health observations to enhance public health surveillance through the Health and Environment Linked for Information Exchange, Atlanta (HELIX-Atlanta) demonstration project. Through this project, NASA Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth observations will be combined with U.S. Environmental Protection Agency monitoring data to create more representative particulate matter products. [Figure 2] High concentrations of particulate matter are associated with adverse health reactions, including respiratory and cardiovascular problems. Additional Earth science satellite observations, such as ozone concentrations (from NASA's Total Ozone Mapping Spectrometer (TOMS) and from the Ozone Monitoring Instrument (OMI) onboard Aura) and surface temperature (from NASA's MODIS and from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard Terra), will also be used to enhance EPHTN/HELIX. The enhanced air quality products that result from this collaboration will forewarn emergency care providers about spikes in respiratory admissions that occur during periods of adverse air quality. In 2004, NASA and the CDC signed a Memorandum of Understanding to formalize the relationship.
Plague surveillance is another CDC priority. Plague is an infectious disease caused by the bacteria Yersinia pestis. Because plague is a Class A disease, by law, all cases or suspected cases of plague must be reported to public health officials at state health departments, who in turn report this information to the CDC. Plague is also monitored by federal agencies for its potential as a bioterrorist agent. Plague prevention and response efforts are underway at regional, state, and local levels through the CDC-sponsored ArboNET/Plague Surveillance System. ArboNET is a passive surveillance system designed to collect and to archive information for the study and operational monitoring of regional and national arthropod-borne viral disease trends. The CDC, participating health departments, the DOD, and the U.S. Geological Survey are the primary users of ArboNET. NASA Earth science observations and model predictive capabilities provide information on plague vector habitats that enhance ArboNET forecasts of outbreak conditions, particularly over the Four Corners region. Plague is endemic in the United States west of the Rocky Mountains, and the Four Corners region is considered particularly susceptible for outbreaks. The goal of NASA's participation in this project is to understand the combination of vegetation, rainfall, and slope characteristics to enable prediction of rodent food supply and the consequent migration of rodent vectors into proximity with humans. The CDC has partnered with NASA to use MODIS Normalized Difference Vegetation Index (NDVI) observations, MODIS surface temperature observations, Shuttle Radar Topography Mission information, Tropical Rainfall Measuring Mission (TRMM) observations, and Landsat 7 land cover observations to predict areas susceptible to plague transmission from rodents to humans. [Figure 3] Earth-system science model capabilities (including the Global Historical Climatology Network (GHCN), the Goddard Space Flight Center (GSFC) Global Modeling and Assimilation Office (GMAO), and the GSFC Plague Algorithm) provide additional information on plague vector habitats that enhance ArboNET forecasts of outbreak conditions. The enhanced ArboNET products that result from this collaboration will inform health care providers on the potential for plague cases to present themselves to hospitals and clinics. These enhanced products may also be used to determine the likelihood that a particular plague outbreak was a function of the environment rather than being induced by some external means (e.g., bioterrorism).
Malaria is another high priority infectious disease target for domestic agencies, such as the CDC and the DOD, as well as for international health entities, such as the World Health Organization and the Pan American Health Organization. Malaria affects nearly 1,600 Americans each year and kills an estimated 3 million people worldwide, many of whom are children. In addition, malaria costs African nations approximately $12 billion in economic productivity. The health and economic consequences of malaria make it a destabilizing phenomenon. Both the CDC and the DOD currently are developing decision support systems to better predict and respond to malaria. [Figure 4]
Earth science observations and model predictive capabilities can enhance these decision support systems by providing new information on vector habitats and environmental conditions that precede malaria outbreaks. The Global Situational Awareness Tool (GSAT) is an environmental planning tool owned and operated by the U.S. Air Force Strategic Operations Command (AFSOC). The GSAT provides environmental safety and health information to AFSOC planners and decision makers. Malaria is a disease of significant interest to the GSAT operators specifically and to military decision makers in general, because it can have a large impact on military operations. For example, approximately one-third of U.S. personnel involved in the 2003 Liberia operation came down with malaria. NASA is currently evaluating the potential of integrating Earth science satellite observations into the GSAT to enhance its ability to track and predict malaria vectors. These observations include radiance values from NASA ASTER, MODIS, and EO-1, precipitation estimates from NASA TRMM, and land cover observations from Landsat 7. [Figure 5] Model predictive capabilities from the GMAO and from the GHCN may also be used to enhance this decision support system. The first use of the NASA-enhanced GSAT is planned during the 2006 DOD Joint Forces Exercise in the western United States and in the Pacific Ocean.
The Rapid Syndrome Validation Project (RSVPTM), a surveillance system that tracks disease syndromes, is sponsored by the Sandia National Laboratory (a research and development center funded by the Department of Energy). The system is operated in conjunction with local and state health departments and with other public health entities. The RSVP is designed to identify infectious disease outbreaks in the earliest possible stages and to alert public health officials to these events. NASA has partnered with the University of New Mexico and with the University of Arizona to integrate Earth-Sun System science observations and predictive modeling capabilities into this decision support tool to enhance the system's ability to identify environmental conditions (for example, dust storms) that precede naturally occurring, chronic, and infectious disease events. A NASA enhanced RSVP will provide real-time syndromic monitoring and analysis with extended capabilities to include environmental and atmospheric information relevant to respiratory illnesses, especially asthma. A variety of NASA Earth science satellite observations are used in this project, including ones from MODIS, TOMS, TRMM, EO-1, and Landsat 7. Model predictive capabilities from the GMAO Catchment Land Surface Model and from the Dust Regional Atmospheric Model (DREAM), among others, are also being used in the RSVP. DREAM is configured as an interoperable module of the National Centers for Environmental Prediction North American Mesoscale model. [Figures 6, 7, and 8]
The Department of Health and Human Services' Secretary's Command Center was created to provide a focal point for public health information and intelligence to the Secretary of the Department of Health and Human Services (DHHS). Located in Washington, DC, the Secretary's Command Center (SCC) coordinates the activities of the DHHS with international, local, state, and federal public health authorities. Since its establishment in December 2002, the SCC's innovative design, information architecture, and business plan have become the benchmarks for similar operations centers being developed for international and federal agencies. The SCC has workstations dedicated for the Secretary, Deputy Secretary, and Assistant Secretary for Public Health Preparedness; for the Surgeon General; and for other division leaders and liaisons from other agencies. The use of the Internet protocol system creates an interoperable system of computers, radios, and telephones. Geospatial systems allow tracking and plotting of events and incidents and their relay to DHHS preparedness and response activity managers/coordinators. Through the SCC, the DHHS monitors developing public health emergencies through as many as 4,000 news media outlets across North, Central, and South America; Europe; and the Middle East. The SCC can monitor local television stations from up to 10 cities at a time to observe how breaking events are being reported across the country. NASA is currently evaluating the SCC to determine possibilities for the integration of NASA Earth science satellite observations and model predictive capabilities. The DHHS and NASA are also in the initial stages of formulating a Memorandum of Understanding between the two agencies to formalize this relationship.
In general, NASA's contribution to epidemiologic surveillance systems is to increase both the descriptive and analytical information available to them. More importantly, enhancement of these systems with NASA research results will increase their predictive value. NASA Earth science satellite observations and model predictive capabilities will also add to the understanding of the distribution and frequency of disease as a function of climate and weather-related phenomena. Research to date has suggested many correlations between these Earth processes and disease. Through all of these efforts, NASA is helping to bring public health surveillance into the 21st century.
Beck, Louisa R., Bradley M. Lobitz, and Byron L. Wood. 2000. Remote sensing and human health: New sensors and new opportunities. Emerging Infectious Diseases, 6(3): 217-26. Also available online at http://www.cdc.gov/ncidod/eid/vol6no3/pdf/beck.pdf (accessed July 27, 2005).
CDC [Centers for Disease Control and Prevention]. 2001. Updated guidelines for evaluating public health surveillance systems: Recommendations from the Guidelines Working Group. Morbidity and Mortality Weekly Report Vol. 50, No. RR-13. Also available online at http://www.cdc.gov/mmwr/PDF/RR/RR5013.pdf (accessed July 28, 2005).
Linthicum, K.J., A. Anyamba, C.J. Tucker, P.W. Kelley, M.F. Myers, and C.J. Peters. 1999. Climate and satellite indicators to forecast Rift Valley Fever epidemics in Kenya. Science, 285: 397-400.
NASA. 2005a. Applications Implementation Working Group (AIWG). Applied Sciences Program, Earth-Sun System Division, Science Mission Directorate. http://aiwg.gsfc.nasa.gov/ (accessed July 27, 2005).
NASA. 2005b. Applied Sciences Program: The Use of Earth-Sun System Science Results for Decision Making. Earth-Sun System Division, Science Mission Directorate. http://science.hq.nasa.gov/earth-sun/applications/index.html (accessed July 27, 2005).
NASA. 2004. Earth Science Applications Plan. Office of Earth Science. NP-2004-08-368-HQ, 104 p. http://science.hq.nasa.gov/strategy/AppPlan.pdf (accessed July 28, 2005).
NASA. 2005c. Earth Science Research Plan. January 6 draft. 61 p. http://science.hq.nasa.gov/strategy/researchPlan.pdf (accessed July 28, 2005).
NASA. 2005d. Public Health Program Element, FY 2005-2009 Plan. Earth-Sun System Applied Sciences Program, NASA Science Mission Directorate. Version 1.1, March 16. 30 p. http://aiwg.gsfc.nasa.gov/esappdocs/progplans/ph_ver1-1.pdf (accessed July 27, 2005).
About the Authors
John Haynes is Program Manager for Public Health Applications in the Applied Sciences Program of the NASA Science Mission Directorate. John graduated from the University of South Alabama in 1999 with a B.S. in meteorology. In 2002, he graduated with an M.S. in meteorology from the University of Oklahoma. The first portion of his thesis work ("Analysis of Warm Season Morning Convection across the Southern Great Plains") was published in the December 2003 edition of Weather and Forecasting. John entered NASA in 2002 through the Presidential Management Fellowship Program. Email: [email protected]; Phone: 202-358-4665; Fax: 202-358-3098; website: http://science.hq.nasa.gov/earth-sun/applications/index.html
Robert A. Venezia is Chief of the Research Division in the Applied Sciences Directorate at the NASA Stennis Space Center. Dr. Venezia graduated from the State University of New York with a B.S. in biochemistry, from the University of Cincinnati with an M.S. in epidemiology, and from the University of Illinois with a Dr.P.H. (Doctor of Public Health). He came to NASA from the Maryland Department of Health and Mental Hygiene where he was Director of the Office of Environmental Health. He has also worked for the Arizona Department of Health Services, and the Association of Schools of Public Health. Email: [email protected]; Phone: 228-688-2094
NASA Article Series
The following articles were originally published in Earth Observation Magazine in the issues indicated below. The first article, "NASA Space Systems Enable Science for Society," introduces the series.
Originally published in the May 2005 issue of Earth Observation Magazine
Originally published in the June 2005 issue of Earth Observation Magazine
Originally published in the July 2005 issue of Earth Observation Magazine
Originally published in the August 2005 issue of Earth Observation Magazine