United States Environmental Protection Agency Office of Research and Development National Exposure Research Laboratory Research Abstract Government Performance Results Act (GPRA) Goal 6 Annual Performance Measure 26 Significant Research Findings: UV Monitoring Research Program Database Scientific In September 1996, the National Park Service (NPS) and the Environmental Problem and Protection Agency (EPA) signed an interagency agreement (IAG) to cooperate on Policy Issues a program of long-term monitoring of environmental stressors at various sites throughout the U.S., and to undertake research on the effects of those stressors on ecosystems. Because exposure to solar ultraviolet (UV) radiation is both an ecosystem and a human health stressor (causing, e.g., sunburn, skin cancer, and immunosuppression), data are needed to improve estimates of ecosystem and human exposure to UV radiation. Additionally, it has been shown that decreases in stratospheric ozone lead to increases in the amount of UV-B (shorter wavelength UV) radiation reaching the earth's surface. It is precisely this shorter wavelength radiation that can be the most biologically damaging. Thus, long-term monitoring of UV radiation is necessary to detect trends that may be produced as a result of changes in stratospheric ozone. Research To address these concerns and meet the requirements of the EPA-NPS agreement, Approach the EPA's National Exposure Research Laboratory (NERL) has set up a network of twenty-one UV monitoring sites throughout the United States. Fourteen of the sites are located in National Parks and are part of the Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet). The remaining seven sites are located in urban areas. Each of the sites are equipped with a Brewer spectrophotometer, an instrument designed to measure different wavelengths of light, with a focus on UV-B (shorter wavelength UV) radiation. These instruments track the sun as they monitor the variation in solar irradiance throughout the day. They also record other data, including total column ozone. These data are used to calculate the dose of UV radiation at the surface of the earth. The University of Georgia (UGA), under contract with the EPA, carried the principal responsibility for all aspects of daily data gathering, including network maintenance and data quality assurance (QA). Their QA plan included an annual calibration of the UV measurements to provide data which are traceable to National Institute for Standards and Technology (NIST) standards. The National Oceanic and Atmospheric Administration (NOAA) provided independent quality control checks. The UGA developed and applied a set of corrections to the raw data, referred to as Level-1 (LI) corrections. The LI corrections are applied to the raw data to remove the outliers and to ensure that the resulting data has undergone ------- quality control to allow it to be used by researchers. The corrected data were then transferred to the EPA for analysis and dissemination to government and non- government scientists and other interested parties. Results and The UV data provided by the EPA UV-Net program will be used by a variety of Impact researchers and scientific organizations. Thus, Level-1 corrected data from each monitoring site have been posted to an EPA web site that is accessible to the general public. The data can be accessed through the following web page: htto: //www .epa. gov/uvnet/acce ss .html. This web page provides links to FTP sites containing the corrected UV data for each of the monitoring sites. The structure and content of the UV data displayed on the publically accessible sites are exactly the same as that provided to the EPA. Data formats and definitions are provided in README files also located through the above web page. These publically available data will be used to further the understanding of UV radiation and its effects on humans and ecosystems in a variety of ways, summarized as follows: Improve our understanding of the nature and intensity of UV (especially UV-B) radiation reaching the earth's surface. Characterize the physical and chemical parameters that modify the UV radiation flux. Obtain better estimates of UV exposures at different times, locations, meteorological conditions, and air pollution conditions. This research is important in helping protect the public against increased UV radiation associated with decreasing stratospheric ozone concentrations. Research The UV-Net program is a collaborative monitoring and research effort between Collaboration and the EPA and NPS. Other significant contributors include the U.S. Geological Research Survey, the USDA Forest Service, NOAA, NIST, the UGA, and other Products universities. Examples of recent publications/presentations resulting from this monitoring program include the following: Hall, E.S., The UV Monitoring Research Program. Presented at: US Global Change Research Program Seminar, Washington, DC, February 24, 2003. Shreffler, J.H. Data from a solar ultraviolet monitoring network. Presented at: Department of Statistics, Chapel Hill, NC, January 22, 2001. Godar, D.E., Wengraitis, S.P., Shreffler, J.H., and Sliney, D. Average annual solar UV dose of the continental US citizen. Presented at: 13th International Congress on Photobiology, San Francisco, CA, July 2-6, 2000. Shreffler, J.H. Data from EPA's UV monitoring network. Presented at: 13th International Congress on Photobiology, San Francisco, CA, July 2-6, 2000. Future Research A future goal for the UV-Net database is to have statistical and trend analysis for the UV data co-resident with the data on the web page. The database provides a valuable resource for addressing many UV research needs. Future research ------- products planned include a report on the effects of haze and clouds on solar UV radiation, and a report on the geographic and seasonal variability of UV affecting human and ecological health. Contacts for Questions and inquiries can be directed to the principal investigator: Additional Eric S. Hall Information jj.S. EPA, Office of Research and Development National Exposure Research Laboratory MD E205-02 Research Triangle Park, NC, 27711 Phone:919-541-3147 E-mail: hall.erics@epa.gov Federal funding for this research was administered under EPA contract 68-D-99- 004, interagency agreement DW139392300 (NOAA), interagency agreement DW1393889501 (NIST), and interagency agreement DW149346601 (NPS). ------- |