title: Water quality, weather and environmental factors associated with fecal indicator organism density in beach sand at two recreational marine beaches.
abstract: Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches - Fairhope Beach, AL and Goddard Beach, RI - with nearby publicly-owned treatment works (POTWs) outfalls. F(+) coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand-water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand. The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency.
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA; Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA. Electronic address: cheaney@jhsph.edu.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Heaney
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA.
authors.forename: Natalie G
authors.initials: NG
authors.lastname: Exum
authors.affiliation: National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268-1593, USA.
authors.forename: Alfred P
authors.initials: AP
authors.lastname: Dufour
authors.affiliation: National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268-1593, USA.
authors.forename: Kristen P
authors.initials: KP
authors.lastname: Brenner
authors.affiliation: National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268-1593, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Haugland
authors.affiliation: National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH 45268-1593, USA.
authors.forename: Eunice
authors.initials: E
authors.lastname: Chern
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA.
authors.forename: Kellogg J
authors.initials: KJ
authors.lastname: Schwab
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Love
authors.affiliation: Department of Environmental Sciences and Engineering, CB# 7431, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431, USA.
authors.forename: Marc L
authors.initials: ML
authors.lastname: Serre
authors.affiliation: Institute of Marine Sciences, CB# 3301, University of North Carolina at Chapel Hill, Morehead City, NC 28557-3301, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Noble
authors.affiliation: Epidemiology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wade
mesh_terms: D001439:Bacteroides / Q000254:growth & development; D041963:Bacteroidetes / Q000254:growth & development; D001493:Bathing Beaches / Q000592:standards*; D003090:Coliphages / Q000254:growth & development; D016983:Enterococcus / Q000254:growth & development; D005243:Feces / Q000382:microbiology*; D011998:Recreation; D012623:Seawater / Q000382:microbiology*; D014481:United States; D014871:Water Microbiology; D060753:Water Quality / Q000592:standards*
keywords: Beach sand; Enterococci; Fecal pollution; Rainfall; Water quality; qPCR