GERMS

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GERMS GEOLOGYDr. Larry McKayJones Professor
of Hydrogeology
UNIVERSITY
of
THE
TENNESSEE

• Dept. of Earth Planetary Sciences
• University of Tennessee

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Outline

• Waterborne Pathogens Fecal Indicators
• UT Research
• Microbial transport in soil rock
• Detection and source identification
• Bangladesh Pathogens Arsenic
• Summary and Acknowledgements

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Waterborne Pathogens
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Waterborne Pathogens
Disease
Exposure
Sources
Transport in water
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Need for Pathogen Research

• Disease outbreaks
• Many rural suburban areas without water
  monitoring or treatment
• New EPA Groundwater Monitoring Rule
• Poor understanding of microbial transport
  occurrence at the field-scale

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Research at Univ. of Tennessee
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Microbial transport in fractured soil

• Soils often contain fractures or root holes that
  act as pathways for rapid flow

Fractured till in Denmark
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Field experiment in Tennessee
Monitoring wells in weathered rock at 6 m depth
Transport rates of up to 50 m/day for
bacteriophage Pseudemonas syringae
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Laboratory-scale Experiments

• microbial transport rates vary widely
• size surface characteristics of microbes
• soil or rock type
• precipitation
• soil/water chemistry

Flow cell containing soil
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Occurrence Detection

• Study of microbial contamination in Tennessee

Collaboration with Dr. Alice Layton
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East Tennessee Virus Survey
Community water supply wells springs that
serve from a few 100 to many 1000s of people
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East Tennessee Virus Survey
Trisha Johnson, Masters student
Collected microbes from up to 1000 L of water
using charged surface filters
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East Tennessee Virus Survey

• Sample elution from filters and analysis with
  tissue culture at EPA labs
• 7 of the 8 sites contained low levels of
  enterovirus or reovirus

Implications? Health risk? Challenges for
pathogen monitoring?
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Bacteroides Project

• Development of fecal indicator technology
• concentration of fecal material in water
• identify fecal sources (cattle, human, horses,
  etc.)

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Bacteroides qPCR assays Based on 16S rRNA
Dan Williams, Technician
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Bacteroides Projects in Tennessee
Dr. Randy Gentry, Engineering

• Fecal source tracking studies in streams and
  groundwater
• Study of fecal sources in rural/urban Stock Creek
  watershed near Knoxville

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15 miles long
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Stock Creek Restoration

• Fecal source data used to help develop watershed
  management plan
• Obtained assistance from US Department of
  Agriculture local water/sewage utility
• providing sewers to houses near creek
• re-establish riparian zones cattle fences

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Bangladesh Arsenic Pathogens

• New water quality project funded by NIH/Fogarty
  International Center
• Collaboration with
• Columbia Univ.
• Barnard College
• Dhaka Univ.
• Univ. of North Carolina
• ICDDR, Bangladesh

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Bangladesh Arsenic Pathogens

• Columbia Univ study on arsenic contamination
• Villages with low arsenic tend to have higher
  occurrence of diarrheal disease
• Why?

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Bangladesh Hypothesis

• Sandy sediments near ground surface
• rapid flow transport of pathogens
• rapid removal of arsenic by flushing
• Clayey sediments near ground surface
• slow flow less pathogen transport
• accumulation of arsenic

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Fecal Transport Pathways

• Latrine infiltration
• Leaks in or around well casing
• Seepage from ponds
• Priming water

Latrine
Pond
Water Table
Sandy sediments allow greater transport of fecal
microbes
Dry season vs Monsoon?
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Latrines
Contaminated Pond
Tubewells
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Fecal Sources

• Many latrines discharge into small ponds or
  streams
• Pond water may leach into soil wells

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Other Pathogen Sources

• Large bathing ponds and water handling or
  storage may also contribute to disease

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Bangladesh Arsenic Pathogens
Peter Knappett, PhD student

• UT role includes
• Better microbial sampling detection methods
• Latrine- pond-well scale transport studies

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Bangladesh Field Studies

• ICDDR,B field site
• - Longitudinal DSS since 1966
• - 200,000 people visited biweekly
• - Health surveillance hospital
• - NC Chapel Hill researchers provide opportunity
  to link disease with occurrence of environmental
  pathogens, fecal indicators sanitary facilities

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Preliminary Results

• Strong seasonal geographic variations in
  occurrence of fecal bacteria in wells
• Bacterial concentrations vary greatly with
  sampling method
• Pathogens are difficult to detect and highly
  variable, even in a fecal-rich environment
• Correlations between diarrheal disease, soil type
  sewage/well infrastructure currently being
  evaluated

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Acknowledgements Questions
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Acknowledgements

• University of Tennessee (Alice Layton, Peter
  Knappett, Dan Williams, Alyssa Bell Trisha
  Johnson)
• Columbia Univ. Barnard College (Lex van Geen,
  Patricia Culligan, Brian Mailloux, Joe Graziano,
  Andrew Ferguson, John Feighery)
• UNC Chapel Hill (Mike Emch, Marc Serre, Larry
  Band, Veronica Escamilla Yasu Akita)
• Dhaka Univ. ICDDR,B (Kazi Matin Ahmed, Jahangir
  Alam, Rezaul Huq, Mohammad Yunus, Kim
  Streatfield)
• Funding from NIH Fogarty International Center/NSF
  Ecology of Infectious Disease Program, State of
  TN, DOE USGS

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Questions?
Pathogens in Hydrology Class Visits CDC