Microbial and chemical contamination during and after flooding in the Ohio River—Kentucky, 2011

Abstract

Surface water contaminants in Kentucky during and after 2011 flooding were characterized. Surface water samples were collected during flood stage (May 2–4, 2011; n = 15) and after (July 25–26, 2011; n = 8) from four different cities along the Ohio River and were analyzed for the presence of microbial indicators, pathogens, metals, and chemical contaminants. Contaminant concentrations during and after flooding were compared using linear and logistic regression. Surface water samples collected during flooding had higher levels of E. coli, enterococci, Salmonella, Campylobacter, E. coli O157:H7, adenovirus, arsenic, copper, iron, lead, and zinc compared to surface water samples collected 3-months post-flood (P < 0.05). These results suggest that flooding increases microbial and chemical loads in surface water. These findings reinforce commonly recommended guidelines to limit exposure to flood water and to appropriately sanitize contaminated surfaces and drinking wells after contamination by flood water.

Keywords:

• Natural disaster
• emergency response
• floods

Acknowledgments

We would like to thank the Kentucky Department of Public Health, particularly CDR Margaret Riggs, USPHS, for their time, expertise, and logistical support. We would also like to thank the Louisville Metro Department of Public Health & Wellness, the Three Rivers District Health Department, the Green River District Health Department, and the Purchase District Health Department for their cooperation during this investigation. The use of trade names and names of commercial sources is for identification only and does not imply endorsement by the CDC or the U.S. Department of Health and Human Services. The findings and conclusions in this report are those of the authors and do not necessarily represent those of the CDC.