Examining Epidemiologic and Environmental Factors Associated with Microbial Risks from Drinking WaterEPA Grant Number: R831727
Title: Examining Epidemiologic and Environmental Factors Associated with Microbial Risks from Drinking Water
Investigators: S. Eisenberg, Joseph N. , Moe, Christine L. , Uber, Jim
Institution: University of California - Berkeley , Emory University , University of Cincinnati
EPA Project Officer: Klieforth, Barbara I
Project Period: December 23, 2004 through December 27, 2007 (Extended to December 27, 2009)
Project Amount: $589,806
RFA: Microbial Risk in Drinking Water (2003) RFA Text | Recipients Lists
Research Category: Nanotechnology , Drinking Water , Health Effects , Water
Results from drinking water intervention trials have provided a wide range of outcomes, ranging from no evidence of risk to attributable risk estimates as high as 35-40%. This range of risk estimates is problematic for regulators. One reason for this variation is due to the differing environmental conditions in each of these studies, such as source water concentrations, treatment barriers, and distribution systems. Risk models can provide insight to these epidemiologic data by interpreting the variability observed across studies. These insights can in turn be used help design future studies. To this end, we propose the following three specific aims: 1) To develop a population-based dynamic model that can be used to characterize drinking water risks to communities and to apply this risk model to human calicivirus (HuCV), an important pathogen on the USEPA Candidate Contaminant List (CCL). 2) To develop an exposure model that describes the pathogen fate and transport from source water through to the distribution system for distribution systems representative of those in urban areas of the U.S. The model will incorporate factors that have a potential role in determining human exposure. 3) To combine the models developed in Specific Aims 1 and 2 and conduct sensitivity studies to categorize those factors with respect to their relative importance in determining risk.
To accomplish Aim 1 we will develop and analyze a disease transmission model that explicitly accounts for multiple transmission pathways and immunity. Human calicivirus (HuCV) will be chosen as the pathogen of concern, using data from the literature, including both Dr. Christine Moe’s (co-investigator) human challenge studies and Dr. Marion Koopmans’ (collaborator) community-based studies, to parameterize the model. For Aim 2 we plan on developing an exposure model that accounts for two contamination pathways, source water and distribution system. Methods will be developed that incorporate surrogate environmental data for HuCV. In Aim 3 the model will be used to conduct sensitivity studies. The goal of these studies will be to help inform regulators on drinking water risks by identifying factors that are most important in determining those risks. These analyses will also provide insight on the design of epidemiology studies that can in turn produce useful data for regulators.
This research project will: 1) help define the role of HuCV in drinking water risks; and 2) elucidate the impact of population-level factors, such as secondary transmission and immunity, as well as environmental factors, such as transport through the distribution system, on risks associated with drinking water.