Grantee Research Project Results
Final Report: Community Based Risk Assessment of Exposure to Contaminants via Water Sources on the Crow Reservation in Montana
EPA Grant Number: R833706Title: Community Based Risk Assessment of Exposure to Contaminants via Water Sources on the Crow Reservation in Montana
Investigators: Ford, Timothy E. , Camper, Anne
Institution: University of New England - University Campus , Montana State University - Bozeman
EPA Project Officer: Aja, Hayley
Project Period: June 1, 2009 through May 31, 2012 (Extended to May 31, 2014)
Project Amount: $329,532
RFA: Issues in Tribal Environmental Research and Health Promotion: Novel Approaches for Assessing and Managing Cumulative Risks and Impacts of Global Climate Change (2007) RFA Text | Recipients Lists
Research Category: Environmental Justice , Climate Change , Tribal Environmental Health Research , Human Health
Objective:
This was a community-based participatory research project and therefore the research was jointly guided and conducted by the Crow Environmental Health Steering Committee (CEHSC) and academic partners. The CEHSC includes representatives of the Apsaalooke [Crow] Water and Wastewater Authority, the Crow Tribal Administration and Tribal Environmental Protection Program, Little Big Horn College (LBHC - the tribal college for the reservation), the local Indian Health Service Hospital and the local non-profit Messengers for Health, along with other community stakeholders. Academic partners included LBHC, Dr. Anne Camper at Montana State University-Bozeman (MSU) and Dr. Tim Ford (now at Shenandoah University). The Steering Committee met and continues to meet monthly to discuss a range of environmental health issues on the Reservation, and provided guidance and input into this risk assessment project (Cummins, et al., 2010). Staff included Project Leader Margaret (Mari) Eggers and local Project Coordinator John Doyle, a Crow Tribal member. More than two dozen LBHC and MSU students have been involved as research interns.
As a community-based participatory research project, researchers will collaborate to accomplish the following objectives:
- Establish a sampling and analysis program to assess contaminant loadings to water and to aquatic/wetland subsistence foods.
- Evaluate lifestyle and cultural practices that contribute to exposure risk from water sources.
- Supplement the current LifeLine TribalTM software to include water contamination and exposure factors specific to Reservation settings.
- Design and support culturally appropriate risk communication and risk management measures that minimize impact on subsistence and other traditional practices, and which may be transferable to other Tribes.
Methods included: (1) bacterial and comprehensive chemical analyses of domestic, cultural and recreational water sources; (2) mercury analyses of local fish; (3) family surveys to assess routes of exposure and to identify risk factors for well contamination; (4) interviews with key informants to elucidate and document the social, cultural, spiritual and economic impacts of water contamination; and (5) use of secondary data from LBHC, the Crow Tribe, the Indian Health Service Hospital, the USGS, and the EPA.
Summary/Accomplishments (Outputs/Outcomes):
Objective A: Establish a sampling and analysis program to assess contaminant loadings to water and to aquatic/wetland subsistence foods.
Home well water
We found that of 160+ wells tested, not a single one met all of the EPA primary and secondary standards for municipal drinking water. Considering contaminants singly, about 55% of home wells are unsafe to drink due to either mineral and/or microbial contamination exceeding EPA standards. Uranium, manganese, and nitrate were the inorganic contaminants most frequently exceeding US EPA standards. At higher concentrations, all three contaminants present serious health risks, especially for infants and children (Brugge, et al., 2005; Brugge, et al., 2011; WHO, 2004; US EPA, 2012; Bouchard, et al., 2010; Ward, et al., 2005; US EPA, 2007; US EPA, 2013). The percent of home wells exceeding the cumulative “hazard index” level of concern (Callahan and Sexton, 2007; US EPA, 2003) considering only these three inorganic contaminants varied from 11.1% to 58.3%, depending on the river valley. More than 75% of wells exceed EPA secondary standards for total dissolved solids and/or hardness, both of which make home well water treatment more complex and expensive. The majority of wells with elevated uranium occur in the river valley that has uranium-bearing formations and former uranium mines in its headwaters (Eggers 2014).
The well water data from our own home well testing program were compared to Indian Health Service (IHS) data for well logs completed at the time the wells were drilled on the Reservation. While the IHS well logs were insufficient to conduct a risk assessment, as no water consumption data were collected, the IHS data (for 600+ wells out of approximately 1000 in use) confirmed that our well water data did not overestimate average levels of contamination. GIS maps showing the spatial distribution of each contaminant have been prepared and provided to IHS, and they are being presented to the community.
Effects and projected impacts of climate change on water resources
Observations made by CEHSC members about decreasing annual snowfall and milder winter temperatures over the 20th century initiated our investigation of local climate and hydrologic data. The resulting analysis of existing local and regional meteorological data confirmed the decline in annual snowfall and an increase in frost free days. In addition, the data show a shift in precipitation from winter to early spring and a significant increase in days exceeding 90ºF (32ºC). Streamflow data show a long-term trend of declining discharge. Elders noted that the changes are affecting fish distribution within local streams and plant species that provide subsistence foods. Concerns about warmer summer temperatures also include heat exposure during outdoor ceremonies that involve days of fasting without food or water. Additional community concerns about the effects of climate change include recent increases in flood and wildfire frequency and severity, as well as declining water quality (Doyle, et al., 2013).
Limited resources as well as the links among ecosystems, cultural practices, and public health are likely to increase the already existing impacts of climate change on reservation communities. Work is beginning this fall to (1) conduct additional research to understand current effects and project future impacts of local climate change on water resources and hence environmental health, (2) implement well owner education, and (3) identify and begin implementation of additional climate change adaptation measures (EPA RD835594, Climate Adaptation and Water Disease Prevention, 8/1/2014 – 7/31/2014).
Waterborne pathogens
We collaborated with MSU Research Associate Steve Hamner, graduate students Sue Broadaway and Crystal Richards, and others to investigate some of the community’s concerns about waterborne pathogens. With the exception of Eggers’ time to coordinate this research with the CEHSC and community (beginning in 2009), these three research projects were funded from other sources. Crystal Richards, in response to CEHSC and broader local concerns about Helicobacter pylori infections in the community, volunteered to investigate this pathogen, as well as Legionella pneumophila and Mycobacteria avium in home drinking water and associated biofilms on the Reservation. Her research detected all three pathogens in both water sources and biofilms (Richards, et al., 2010). Our project staff conducted most of the sample collection around the Reservation and participated in manuscript editing.
Dr. Steve Hamner worked with us to investigate whether the extensive confined animal feeding operation (CAFO) upriver of the all the Reservation communities along the Little Big Horn River was contributing to the high levels of E. coli contamination polluting the river, especially during spring runoff. Hamner and his student interns, with fieldwork support from our project staff, found various pathogenic serotypes of E. coli, including O157:H7, some of which harbored intimin and/or Shiga toxin genes, in the Little Big Horn River both below the CAFO and in a popular children’s swimming hole at Crow Agency (Hamner, et al., 2013).
Another community concern was the adequacy of municipal water treatment for Crow Agency, given the extremely high levels of E. coli contamination in the treatment plant’s Little Big Horn River source water during spring runoff, which placed the plant in EPA’s “Bin 4” – the highest risk category for the presence of other pathogens such as Cryptosporidium (US EPA, 2001). Camper, Eggers, Crow Treatment Plant staff, and MSU students conducted an analysis of the Crow Agency Water Treatment Plant, which found that the existing treatment technology was likely to be inadequate to completely remove Cryptosporidium oocysts from the plant’s source water. Susan Broadaway, advised by Dr. Barry Pyle, found oocysts in all nine source water samples taken from the treatment plant over the course of a year. In June and July, following a major spring flood, the concentration of oocysts peaked and subsequently broke through into treated municipal water. Our project staff provided suggestions for their EPA grant proposal (Pyle, P.I., US EPA FP916744010) as to how their research could help meet Crow community needs, collected most of the samples at the Treatment Plant, and reviewed the draft article (Broadaway, 2013).
All three collaborating researchers made several trips to the Crow Reservation to conduct fieldwork and to present and discuss their results with the CEHSC.
Objective B: Evaluate lifestyle and cultural practices that contribute to exposure risk from water sources.
For families with home wells, well and septic system maintenance practices and risk factors were assessed through almost 240 home surveys conducted with the well water testing. Survey data on well and septic system factors were compared with well water nitrate concentrations to examine whether septic systems or livestock could be contributing to elevated nitrate levels. T-tests comparing well water data with survey data found that Big Horn River valley residents were significantly more likely to have high nitrate levels in their well water than Little Big Horn Valley residents (p = 0.02). Seventy-six percent of the Reservation is in farmland, with the majority of irrigated agriculture occurring in the Big Horn River Valley. No statistically significant relationships were found between well water nitrate concentration and lack of home septic system maintenance or proximity to the septic system or livestock presence. The primary source of high nitrate levels in well water thus appears to be farming practices, rather than homeowner management of their septic systems or livestock (Eggers, 2014).
Survey responses also were used to analyze well water consumption data against well water quality data. Ten percent of families relying on home wells are consuming well water sufficiently contaminated to incur a health risk, considering only these three inorganic contaminants (Eggers, 2014).
Objective C: Supplement the current LifeLine TribalTM software to include water contamination and exposure factors specific to Reservation settings.
LifeLine TribalTM software was not originally designed to incorporate microbial risk assessment. Although a risk assessment model that incorporates both chemical and microbial exposures, and effectively models the complexities of traditional behaviors, may eventually be developed, we did not think that at this time the LifeLine model would work for our needs, and focused our efforts on project objectives A, B, and D.
Objective D: Design and support culturally appropriate risk communication and risk management measures that minimize impact on subsistence and other traditional practices, and which may be transferable to other Tribes.
We made a substantial effort to provide well water test results to the well owners. In addition to the original laboratory report on their well water, families received (1) a letter explaining any health risks and/or plumbing maintenance issues associated with their well test results, (2) a spreadsheet showing how their test results compared to EPA standards – with any exceedances highlighted in red for health risks or yellow for plumbing and aesthetic issues, (3) one-page flyers specific to any contaminant issues for their well (Montana Well Educated Program Exit), (4) a DVD about protecting their well water and demonstrating how to shock chlorinate their well (MSU EWQP, 2009) and (5) a booklet on home water treatment technology options (Vogel, 1991). While some families found these materials to be helpful, many wanted the opportunity to sit down and talk with a project staff member to have the results explained in person. Our Project Coordinator and graduate student intern subsequently paid home visits to as many of the participating families as they could reach.
Our most successful risk management approach was to collaborate with the Apsaalooke [Crow] Water and Wastewater Authority (AWWA). They needed research to determine the nature and extent of contamination of surface water used as source water for municipal treatment, and we needed someone with the mandate and expertise to manage and improve municipal water and wastewater treatment. Two AWWA Directors also serve as founding and ongoing members of the CEHSC, which has allowed us to design and conduct research yielding the data needed for their fundraising and long-range planning. To date, the AWWA has raised more than $20 million to upgrade and replace water and wastewater infrastructure for the town of Crow Agency, the largest community on the Reservation. In an effort to share lessons learned with other Tribes and rural communities, the AWWA Directors/CEHSC members and project staff presented their work as a plenary address at the National Congress of American Indians Tribal Leaders/Scholars Forum (Doyle, et al., 2012), as an EPA Blog (Eggers, et al., 2013), as posters at the EPA/IHS/NIMHD/CDC/OMH sponsored 2013 Environmental Health Disparities & Environmental Justice Meeting (Doyle, et al., 2013, Eggers, et al., 2013), as a panel and poster at the 2012 National Institutes of Health Science of Eliminating Health Disparities Summit (Eggers, et al., 2012, Doyle, et al., 2012), as an EPA Tribal Environmental Health Research Program national webinar (Ford, et al., 2012) and as a panel presentation at EPA’s 2010 National Tribal Science Forum (Cummins, et al., 2010). The EPA’s National Center for Environmental Research also has included a summary of our work in its recent publication, “A Decade of Tribal Environmental Research: Results and Impacts from EPA’s Extramural Grants and Fellowship Programs” (US EPA, 2014).
An additional risk management strategy that we are pursuing is pilot testing a high-tech, low-cost home water treatment filtration system. Designed for use initially in developing countries, the system is essentially a small-scale version of a traditional municipal water treatment plant, which effectively removes sediment and microbial contamination but not dissolved metals. As it does not use electricity, it can be operated for pennies a day. As many Crow families were still hauling river water for home use until the 1960s, our Steering Committee thought it was worth trying out a system that would treat river water for domestic use. An initial filter design was pilot tested by five families in 2013; feedback from the pilot testing has resulted in design modifications to improve ease of use, and discussions currently are under way with the manufacturer about Crow Reservation community members pilot testing the revised design (Dietrich, et al., 2014).
We also have sought and secured funding to implement the above described measures to reduce risks of microbial exposures from home well water, which has become a widespread local issue with the increased severity and frequency of spring floods.
Conclusions:
Exposure to contaminated well water exacerbates the Crow Reservation community’s existing health disparities due to the confluence of the area’s geology (Moore-Nall, et al., 2013), extensive agriculture (USDA, 2002; USDA, 2007), lack of public environmental health education, jurisdictional complexities of reservations (Doyle, et al., 2013), already vulnerable health status (Mark and Byron, 2010; MT DPHHS, 2006), and especially families’ limited financial resources (BIA, 2005; US Census, 2010a; US Census, 2010b) for mitigating poor quality well water (Eggers, 2014).
References:
Bouchard MF, Sauve S, Barbeau B, et al. 2011. Intellectual impairment in school-age children exposed to manganese from drinking water. Environ Health Perspect 119(1):138-14.
Broadaway SC. 2013. Detection of Cryptosporidium and E. coli using fluorescent in situ hybridization and solid phase laser cytometry. Master’s Thesis, Montana State University, Bozeman, MT.
Brugge D, De Lemos JL, Oldmixon B. 2005. Exposure pathways and health effects associated with chemical and radiological toxicity of natural uranium: a review. Rev Environ Health 20(3):177-193.
Brugge D, Buchner V. 2011. Health effects of uranium; new research findings. Rev Environ Health 26(4):231-249.
Bureau of Indian Affairs. 2005. Unemployment rate for Crow Tribe. Cited in: Crow Reservation Demographic and Economic Information. 2013. Crow Tribe. Crow Agency, MT.
Callahan MA, Sexton K. 2007. If cumulative risk assessment is the answer, what is the question? Environ Health Perspect 115(5):799-806.
Cummins C, Doyle JT, Kindness L, Lefthand MJ, Bear Don’t Walk UJ, Bends A, Broadaway SC, Camper AK, Fitch R, Ford TE, Hamner S, Morrison AR, Richards CL, Young SL, Eggers MJ. 2010. Community-based participatory research in Indian country: improving health through water quality research and awareness. (PDF, 9pp, 43KB) Family & Community Health 33(3):166-174. PMCID #20531097.
Dietrich E, Rao V, Doyle JT, Eggers MJ, Allen C, Kuennen R, Camper AK. 2015. Industry-partnered service-learning addressing drinking water quality with a native community. Journal of Higher Education Outreach and Engagement. In review.
Doyle JT, Kindness L, Bear Don’t Walk U, Realbird J, Eggers MJ, Crow Environmental Health Steering Committee, Ford TE, Camper AK. 2013. Addressing Disparities in Safe Drinking Water Access on the Crow Reservation, Montana. Poster presented at the Environmental Health Disparities and Environmental Justice Meeting, Raleigh, NC, July 29-31, 2013.
JT, Redsteer MH, Eggers MJ. 2013. Exploring effects of climate change on Northern Plains American Indian health. Clim Change 120:643-655.
Doyle JT, Kindness L, Bear Don’t Walk U, Realbird J, Eggers MJ, Old Coyote TJ, Crow Environmental Health Steering Committee, Ford TE, Camper AK. 2012. Addressing disparities in safe drinking water access on the Crow Reservation, Montana. Poster presented at the NIH Summit on the Science of Eliminating Health Disparities. National Harbor, MD, Dec 17, 2012.
Doyle JT, Kindness L, Bear Don’t Walk UJ. Additional contributors: Realbird J, Eggers MJ, Bends AL, Crow Environmental Health Steering Committee, Camper AK. 2012. For as long as the grass shall grow and the rivers shall flow: clean water, a sovereign responsibility. Plenary talk at the National Congress of American Indians Tribal Leader/Scholar Forum, Lincoln, NE, June 19, 2012.
Eggers, MJ. 2014. Community based risk assessment of exposure to waterborne contaminants on the Crow Reservation, Montana. Doctoral Dissertation, Montana State University, Bozeman, MT.
Eggers MJ, Doyle JT, Lefthand ML, Kindness L, Young SL, Good Luck BT, McCormick AKHG, Dietrich E, Felicia DL, Ford TE, Roberts D, Camper AK. 2013. Community-based risk assessment of exposure to waterborne contaminants, Crow Reservation, Montana. Poster presented at the Environmental Health Disparities and Environmental Justice Meeting, Raleigh, NC, July 29-31, 2013.
Eggers MJ, Doyle JT, Old Coyote TJ and Camper AK (presenters), Crow Environmental Health Steering Committee, Ford TE. 2012. Addressing health disparities and learning science through community based participatory research, Crow Reservation, Montana. Presented at the NIH Summit on the Science of Eliminating Health Disparities, National Harbor, MD, December 17, 2012.
Eggers MJ, Lefthand MJ, Young SL, Doyle JT, Plenty Hoops A. 2013. When it comes to water, we are all close neighbors. EPA Blog It All Starts With Science. June 6, 2013.
Ford TE, Eggers MJ, Old Coyote TJ, Good Luck B and Felicia DL. Additional contributors: Doyle JT, Kindness L, Leider A, Moore-Nall A, Dietrich E, Camper AK. 2012. Comprehensive community-based risk assessment of exposure to water-borne contaminants on the Crow Reservation. EPA Tribal Environmental Health Research Program Webinar. October 17, 2012.
Hamner S, Broadaway SC, Berg E, Stettner S, Pyle BH, Big Man N, Old Elk J, Eggers MJ, Doyle J, Kindness L, Good Luck B, Ford TE, Camper AK. 2013. Detection and source tracking of Escherichia coli, harboring intimin and Shiga toxin genes, isolated from the Little Bighorn River, Montana. Int J Environ Health Res 24(4):341-362.
Mark D, Byron R. 2010. Big Horn Valley Health Center Program Narrative. Hardin, MT.
Montana Department of Public Health and Human Services. 2006. Big Horn County Health Profile.Exit
Montana State University Extension Water Quality Program. 2009. Taking Care of Your Ground Water: A Homeowner’s Guide to Well and Septic Systems (YouTube Video) Exit
Montana State University Extension Well Educated Program. Available: http://waterquality.montana.edu/docs/WellEducated.shtml [accessed 2012].
Moore-Nall A, Eggers MJ, Camper AK, Lageson D. 2013. Elevated uranium and lead in wells on the Crow Reservation, Big Horn County – a potential problem. Presented at the Earth Science Colloquium, April 13, 2013, Bozeman, MT.
Richards CL, Broadaway SC, Eggers MJ, Colgate E, Doyle J, Pyle BH, Camper AK, Ford TE. 2010. 'Detection of Mycobacteria, Legionella, and Helicobacter in drinking water and associated biofilms on the Crow Reservation, Montana, USA' in Richards CL. 2010. The detection, characterization, and cultivation of nonculturable Helicobacter pylori. Doctoral Dissertation, Montana State University, Bozeman, MT.
U.S. Census Bureau. 2010a. DP-1-Geography-Big Horn County, Montana: Profile of General Population and Housing Characteristics: 2010. Available: http://factfinder2.census.gov/ [accessed 25 November 2013].
U.S. Census Bureau. 2010b. Montana Locations by Per Capita Income. Exit
U.S. Department of Agriculture, National Agricultural Statistics Service. 2002. Crow Reservation Information 2002, Montana.
U.S. Department of Agriculture. National Agricultural Statistics Service. 2007. 2007 Census of Agriculture. American Indian Reservations Volume 2 • Subject Series • Part 5AC-07-S-5 (PDF) (PDF, 149pp, 2.99MB).
U.S. Environmental Protection Agency. 2003. Framework for Cumulative Risk Assessment. EPA/630/P-02/001F. Washington, D.C.
U.S. Environmental Protection Agency. 2007. Nitrates and Nitrites: Toxicity and Exposure Assessment for Children’s Health (TEACH) Chemical Summary.
U.S. Environmental Protection Agency. 2012. Uranium.
U.S. Environmental Protection Agency. 2013. National Primary Drinking Water Regulations.
U.S. Environmental Protection Agency. 2014. A Decade of Tribal Environmental Research: Results and Impacts from EPA’s Extramural Grants and Fellowship Programs. Tribal Environmental Health Research Program, NCER, ORD, EPA. Washington, D.C.
Vogel MP. 1991. Household drinking water and treatment. Montana State University Extension Service, Bozeman, MT.
Ward MH, deKok TM, Levallois P, Brender J, Gulis G, Nolan BT, VanderSlice J. 2005. Workgroup report: drinking-water nitrate and health – recent findings and research needs. Environ Health Perspect 113(11):1607-1614.
World Health Organization. 2004. Uranium in Drinking Water: Background Document for Development of WHO Guidelines for Drinking Water Quality. (PDF) (PDF, 29pp, 288KB)
Journal Articles on this Report : 8 Displayed | Download in RIS Format
Other project views: | All 55 publications | 8 publications in selected types | All 8 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Christopher S, Saha R, Lachapelle P, Jennings D, Colclough Y, Cooper C, Cummins C, Eggers MJ, FourStar K, Harris K, Kuntz SW, LaFromboise V, LaVeaux D, McDonald T, Real Bird J, Rink E, Webster L. Applying indigenous community-based participatory research principles to partnership development in health disparities research. Family and Community Health 2011;34(3):246-255. |
R833706 (2011) R833706 (Final) |
Exit Exit |
|
Cummins C, Doyle J, Kindness L, Lefthand MJ, Bear Don’t Walk UJ, Bends A, Broadaway SC, Camper AK, Fitch R, Ford TE, Hamner S, Morrison AR, Richards CL, Young SL, Eggers MJ. Community-based participatory research in Indian country: improving health through water quality research and awareness. Family & Community Health 2010;33(3):166-174. |
R833706 (2009) R833706 (2010) R833706 (Final) |
Exit |
|
Doyle JT, Redsteer MH, Eggers MJ. Exploring effects of climate change on Northern Plains American Indian health. Climatic Change 2013;120(3):643-655. |
R833706 (Final) |
Exit |
|
Eggers MJ, Moore-Nall AL, Doyle JT, Lefthand MJ, Young SL, Bends AL, Crow Environmental Health Steering Committee, Camper AK. Potential health risks from uranium in home well water: an investigation by the Apsaalooke (Crow) Tribal Research Group. Geosciences 2015;5(1):67-94. |
R833706 (Final) R835594 (2015) R835594 (2018) |
Exit Exit Exit |
|
Hamner S, Broadaway SC, Berg E, Stettner S, Pyle BH, Big Man N, Old Elk J, Eggers MJ, Doyle J, Kindness L, Good Luck B, Ford TE, Camper AC. Detection and source tracking of Escherichia coli, harboring intimin and Shiga toxin genes, isolated from the Little Bighorn River, Montana. International Journal of Environmental Health Research 2014;24(4):341-362. |
R833706 (Final) |
Exit Exit Exit |
|
McOliver CA, Camper AK, Doyle JT, Eggers MJ, Ford TE, Lila MA, Berner J, Campbell L, Donatuto J. Community-based research as a mechanism to reduce environmental health disparities in American Indian and Alaska Native communities. International Journal of Environmental Research and Public Health 2015;12(4):4076-4100. |
R833706 (Final) R833707 (Final) R834791 (Final) |
Exit Exit |
|
Richards CL, Buchholz BJ, Ford TE, Broadaway SC, Pyle BH, Camper AK. Optimizing the growth of stressed Helicobacter pylori. Journal of Microbiological Methods 2011;84(2):174-182. |
R833706 (Final) |
Exit Exit Exit |
|
Richards CL, Broadaway SC, Eggers MJ, Doyle J, Pyle BH, Camper AK, Ford TE. Detection of pathogenic and non-pathogenic bacteria in drinking water and associated biofilms on the Crow Reservation, Montana, USA. Microbial Ecology 2015:12 pp. |
R833706 (Final) |
Exit |
Supplemental Keywords:
Community-based participatory research, community-engaged research, well water, water quality, drinking water, exposure, cumulative risk assessment, risk communication, risk mitigation, Native American, American Indian, health disparities, environmental justice, environmental health, climate change, uranium, manganese, nitrate, GIS, tribal, tribesProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
- 2012 Progress Report
- 2011 Progress Report
- 2010 Progress Report
- 2009 Progress Report
- Original Abstract
8 journal articles for this project