Environmental Public Health Tracking (EPHT) tracks the occurrence and magnitude of environmental hazards and associated adverse health effects over time. The EPHT program has formally expanded its scope to include finished drinking water quality.
Our objective was to describe the features, strengths, and limitations of using finished drinking water quality data from community water systems (CWSs) for EPHT applications, focusing on atrazine and nitrogen compounds in 8 Midwestern states.
Water quality data were acquired after meeting with state partners and reviewed and merged for analysis.
Data and the coding of variables, particularly with respect to censored results (nondetects), were not standardized between states. Monitoring frequency varied between CWSs and between atrazine and nitrates, but this was in line with regulatory requirements. Cumulative distributions of all contaminants were not the same in all states (Peto-Prentice test P < .001). Atrazine results were highly censored in all states (76.0%-99.3%); higher concentrations were associated with increased measurement frequency and surface water as the CWS source water type. Nitrate results showed substantial state-to-state variability in censoring (20.5%-100%) and in associations between concentrations and the CWS source water type.
Statistical analyses of these data are challenging due to high rates of censoring and uncertainty about the appropriateness of parametric assumptions for time-series data. Although monitoring frequency was consistent with regulations, the magnitude of time gaps coupled with uncertainty about CWS service areas may limit linkage with health outcome data.
This article describes features, strengths, and limitations of using finished drinking water quality data from community water systems for Environmental Public Health Tracking applications, focusing on atrazine and nitrogen compounds in 8 Midwestern states.
Divisions of Environmental and Occupational Health Sciences (Dr Jones) and Epidemiology and Biostatistics (Drs Graber, Turyk, and Stayner), School of Public Health, and Department of Civil and Materials Engineering, College of Engineering (Dr Rockne), University of Illinois at Chicago.
Correspondence: Rachael M. Jones, PhD, MPH, Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, 2121 W. Taylor St (MC 922), Chicago, IL 60612 (email@example.com).
This work was funded by the Centers for Disease Control and Prevention Contract 200-2010-37442. The authors acknowledge the collaboration of their state partners, including the Iowa, Minnesota, Missouri, and Wisconsin EPHT teams; and Frank Hal, Rich Magni, Kris Phillips, and April Swift for their assistance with data acquisition and clarification. The authors also acknowledge Janice Panichello and Jim VanDerslice for informative discussions of their research findings and experiences.
The authors declare no conflicts of interest.