Abstract
Human contact with fecally contaminated waters often raises public health concern. The infection potential closely relates to the fecal source type and the aging persistence of waterborne pathogens. In this study, the health risk of contracting gastroenteritis from exposure to aging fecal contamination was predicted using source-associated markers. Microbial decay characteristics in typical summer seawater were incorporated into a pathogen dose estimation model for a constant fecal input. Results show that the median illness probability commensurate with the health benchmark of 36/1000 corresponded to the marker concentrations of ∼7.8, ∼6.6, ∼3.7, and ∼3.5 log10 gene copies/100 mL for seagulls, cattle, raw sewage, and treated effluent, respectively. The error in risk estimates due to neglecting microbial decay was linearly correlated to the decay differences between markers and pathogens. Specifically, the health risk associated with nonhuman sources, which was primarily contributed by bacterial and parasitic pathogens, can be substantially overestimated, while that for virus-dominated human sources was insignificantly affected by the differential decay. Additionally, seagulls dominated the Enterococcus concentration in waters with a mixture of the above-mentioned sources, although they posed limited health risk. This study provides an approach to understanding the influence of fecal aging on health risk estimation.
Original language | English (US) |
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Pages (from-to) | 921-929 |
Number of pages | 9 |
Journal | Environmental Science and Technology |
Volume | 54 |
Issue number | 2 |
DOIs | |
State | Published - Jan 21 2020 |
Bibliographical note
Funding Information:This study was supported, in part, by the National Natural Science Foundation of China (NSFC) (Grant No. 51578441 and 51778522), and National Key Research and Development Program of China (No. 2017YFE0127300). B.W. was supported by the China Scholarship Council (CSC). We acknowledge four anonymous reviewers who provided suggestions to improve the manuscript.
Publisher Copyright:
© 2019 American Chemical Society.