An Exposure and Health-Risk Assessment of Cryptosporidium Parvum in Relation to Farmland Management Practices in the Merrimack River Basin

EPA Grant Number: F07D30743
Title: An Exposure and Health-Risk Assessment of Cryptosporidium Parvum in Relation to Farmland Management Practices in the Merrimack River Basin
Investigators: Quady, Allie
Institution: Tufts University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2007 through January 1, 2010
RFA: STAR Graduate Fellowships (2007) RFA Text |  Recipients Lists
Research Category: Health Effects , Academic Fellowships


The objective of this project is to formulate a health risk assessment for downstream communities on the Merrimack River by evaluating the relationship of the annual cycle of agricultural and environmental management practices on upstream dairy farms to the varying loads of Cryptosporidium parvum (a common enteric pathogen) in surface water destined for downstream municipal use. Since the mid 1990s, Cryptosporidium, or CP, has been detected in the Merrimack River in New Hampshire, as well as downstream in the Lowell, Massachusetts drinking water supply and in the New York City reservoir (Ascolillo, 2004). Cryptosporidium (CP) is a protozoa that can cause diarrhea or even death in immunocompromised individuals. It is commonly found in manure and is extremely difficult to control in the water supply due to its encasement in a hard shell or oocyst, rendering it resistant to chlorine and other disinfectants (LeChevalier, Norton; 1991). Previous studies have indicated that manure management practices play a role in CP transmission (Jenkins et al, 1999). This project will provide data needed to model and understand the efficacy of specific environmental management techniques in reducing the health risks of exposed communities to CP.


River samples will be taken upstream and downstream from farm systems to assess their CP loads. Sampling will occur at regular intervals and will be timed so as to coincide with the annual agricultural cycle as well as a range of meteorologic events. Farm activities, farm and environmental management techniques, temperature, pH and seasonal river flow fluctuations will be considered as variables in modeling CP concentration in the Merrimack River. Upon completion of annual data collection, generalized linear mixed models will be used to assess the exposure of CP infection in downstream communities. The combination of this data with previous studies of cryptosporidiosis in Lowell will be used to create a health risk-assessment of CP transmission from upstream agricultural sources.

Expected Results:

Certain environmental behaviors of farmers are predicted to cost-effectively decrease the exposure and health-risks of downstream communities in regard to CP. Specific dairy farm agricultural practices are expected to significantly increase surface water levels of CP, thereby influencing the exposure of downstream communities to CP. The health risk assessment will aid local authorities and the EPA in formulating public health guidelines and environmental regulations for CP.

Supplemental Keywords:

RFA, Scientific Discipline, Water, Environmental Microbiology, Biochemistry, Environmental Monitoring, Biology, Drinking Water, cryptosporidium parvum oocysts, fate and transport, health effects, drinking water monitoring, agricultrual environment, drinking water contaminants, human health, drinking water system

Progress and Final Reports:

  • 2007
  • 2008
  • Final