Pediatric Emergency Department Visits for Diarrheal Illness Increased After Release of Undertreated Sewage

Medical College of Wisconsin, Milwaukee, Wisconsin, United States
PEDIATRICS (Impact Factor: 5.47). 12/2007; 120(6):e1472-5. DOI: 10.1542/peds.2007-0283
Source: PubMed


Contamination of local waterways may occur through release of partially treated sewage. The Environmental Protection Agency has recently reviewed regulatory standards for this practice. However, the health effects of these events have not been well studied.
Our goal was to identify any increase in visits to a pediatric emergency department for diarrheal illness after sewage bypass into Lake Michigan.
The study was conducted as a retrospective, observational time-series analysis in a tertiary care children's hospital emergency department with an annual volume of approximately 45,000 visits. We collected data for 2002-2004 pertaining to the daily number of emergency department visits for children (aged <19 years) for diarrheal illness (using specified International Classification of Diseases, Ninth Edition codes as a reference). Daily diarrheal illness visits were the dependent variable in a time-series model. The primary independent variable was the occurrence of a sewage-bypass event in the 3 to 7 preceding days. Potential confounders included the season and daily rainfall. Separate models were created for visits from people living in zip codes that used Lake Michigan drinking water and those who used other water sources.
Over the 3-year study period, there was a mean of 5.0 +/- 3.8 (SD) daily visits for diarrheal illness from people who lived in zip codes that used Lake Michigan drinking water and 1.2 +/- 1.4 (SD) from outside that area. There were 6 sewage-bypass events identified. After adjusting for the season and rainfall, there was a significant increase of 2.5 to 2.7 visits only from people who lived in zip codes that used Lake Michigan drinking water after the 2 largest of the 6 bypass events.
Emergency department visits for diarrheal illness increased significantly after 2 events of release of partially treated sewage into area waterways. These data suggest a potentially harmful effect of such practices.

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Available from: Cheryl Nenn, Aug 21, 2015
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    • "Using a risk assessment approach, one study estimated the risk of contracting GI illness from incidental ingestion of water affected by CSO outfalls ranged from 0.14 to nearly 0.70 over the course of a year for visitors and recreators, respectively (Donovan et al. 2008). Our findings in the Exposed – Drinking Water Region are consistent with the findings of Redman et al. who found that pediatric emergency room visits for diarrheal illness increased 3-7 days following sewage bypass events for those using drinking water from Lake Michigan (Redman et al. 2007). Another study in Wisconsin also demonstrated associations between a winter sewage release event and increased pediatric visits for GI illness (Drayna et al. 2010). "
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