Microbial pathogens in source and treated waters from drinking water treatment plants in the United States and implications for human health.
An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus (quantitative PCR [qPCR]); and the bacteria Legionella pneumophila (qPCR), Mycobacterium avium, M. avium subspecies paratuberculosis, and Mycobacterium intracellulare (qPCR and culture). Cryptosporidium and Giardia were detected in 25% and in 46% of the source water samples, respectively (treated waters were not tested). Aspergillus fumigatus was the most commonly detected fungus in source waters (48%) but none of the three fungi were detected in treated water. Legionella pneumophila was detected in 25% of the source water samples but in only 4% of treated water samples. M. avium and M. intracellulare were both detected in 25% of source water, while all three mycobacteria were detected in 36% of treated water samples. Five species of mycobacteria, Mycobacterium mucogenicum, Mycobacterium phocaicum, Mycobacterium triplex, Mycobacterium fortuitum, and Mycobacterium lentiflavum were cultured from treated water samples. Although these DWTPs represent a fraction of those in the U.S., the results suggest that many of these pathogens are widespread in source waters but that treatment is generally effective in reducing them to below detection limits. The one exception is the mycobacteria, which were commonly detected in treated water, even when not detected in source waters.
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Dawn N
DN
King
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Maura J
MJ
Donohue
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Stephen J
SJ
Vesper
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Eric N
EN
Villegas
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Michael W
MW
Ware
Department of Internal Medicine, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45229, United States.
Megan E
ME
Vogel
U.S. Geological Survey, Denver Federal Center, P.O. Box 25585, Denver, CO 80225, United States.
Edward F
EF
Furlong
U.S. Geological Survey, 400 S. Clinton Street, Iowa City, IA 52240, United States.
Dana W
DW
Kolpin
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States.
Susan T
ST
Glassmeyer
Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency, 26 West Martin Luther King Dr., Cincinnati, OH 45268, United States. Electronic address: pfaller.stacy@epa.gov.
Stacy
S
Pfaller
D060766:Drinking Water / Q000382:microbiology*; D006801:Humans; D009161:Mycobacterium; D014481:United States; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
D060766:Drinking Water
Drinking water; Occurrence; Pathogens; Source water; Treatment