Library
Beach Health Research Articles
2007
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P-Q | R | S | T | U | V | W | X-Y-Z
A
Application of a Human Fecal Marker Assay to Diverse Coastal Environments
in California and Hawaii
Authors: * Layton, B, Boehm, A
Affiliation: Stanford University, Department of Civil & Environmental Engineering, Stanford, CA 94305,
United States
Source: American Geophysical Union, 2007, 88(23)
Abstract: Bacterial pollution at beaches is a growing problem of increasing national concern. Currently, the EPA uses Enterococcus as one measure of water quality for recreational contact. Recent work has suggested that rather than indicating anthropogenic pollution, enterococci may be indigenous to the environment. A human-specific gene marker for Enterococcus faecium (known as esp) was recently proposed as a molecular test for bacterial contamination of human origin. The present study applied the esp gene assay to a variety of coastal environments in California and Hawaii, including groundwater, sand, freshwater creeks, estuaries, and the surf zone. Results indicate that enterococci of human origin are present in many of these environments, suggesting that at least a portion of the bacterial pollution at these sites is a result of anthropogenic inputs rather than autochthonous microbial populations.
Are Existing Bacterial Indicators Adequate for Determining Recreational
Water Illness in Waters Impacted by Nonpoint Pollution?
Authors: Schwab, D. J., Kellogg J.
Affiliation: Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD.
Source: Epidemiology January 2007, 18(1): 21-22
Abstract: Tens of millions of persons swim in coastal waters in the United States each year. In many instances, these waterways are contaminated with fecal pollution that can contribute to recreational water illness. Unfortunately, monitoring recreational waters for disease-causing microorganisms is not as straightforward as it would seem. In addition to the well-known pathogenic bacteria such as Escherichia coli, Salmonella, and Shigella, protozoa including Cryptosporidium and Giardia and viruses, in particular noroviruses and adenoviruses, are also major contributors to recreational water illness. Protozoa and viruses persist in the environment for much longer periods of time than do bacteria, and virus transport through surface and subsurface water is both faster and farther than that of bacteria. The great diversity in pathogenic microorganisms that can be transmitted by water and the difficulty in developing and implementing detection strategies for all possible microbes has resulted in the selection of a few indicator organisms to determine the presence and magnitude in a waterway of microorganisms causing recreational water illness. These classic indicators include total coliforms, fecal coliforms, E. coli, and enterococci, many of which have been used as indicators for over 100 years.
B
Beach Sand and Sediments are Temporal Sinks and Sources of Escherichia coli
in Lake Superior
Authors: Satoshi Ishii, Dennis L. Hansen, Randall E. Hicks, and Michael J. Sadowsky
Affiliations: Department of Soil, Water, and Climate, Center for Microbial and Plant
Genomics, and BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108,
and Department of Biology, University of Minnesota-Duluth, Duluth, Minnesota 55812
Source: Environmental Science & Technology, 41 (7), 2203-2209, 2007.
Abstract: The Duluth Boat Club (DBC) Beach, located in the Duluth-Superior harbor of Lake Superior, is frequently closed in summer due to high counts of Escherichia coli, an indicator of fecal contamination. However, the sources of bacteria contributing to beach closure are currently unknown. In this study, we investigated the potential sources of E. coli contaminating the DBC beach by using modified rep-PCR (HFERP) DNA fingerprinting. Over 3600 E. coli strains were obtained from 55 lake water, 25 sediment, and 135 sand samples taken from five transects at the DBC beach at 11 different times during the summer through fall months of 2004 and 2005. Potential sources of E. coli at this beach were determined by using a known-source DNA fingerprint library containing unique E. coli isolates from wildlife, waterfowl, and treated wastewater obtained near Duluth, MN. Amounts E. coli in the samples were enumerated by membrane filtration counting, and the presence of potentially pathogenic E. coli was determined by using multiplex PCR. E. coli counts in all samples increased during the summer and early fall (July to September). While E. coli in spring samples originated mainly from treated wastewater effluent, the percentage of E. coli from waterfowl increased from summer to fall. DNA fingerprint analyses indicated that some E. coli strains may be naturalized, and autochthonous members of the microbial community in the beach sand and sediments were examined. However, multiplex PCR results indicated that ‹1% of the E. coli strains at the DBC was potentially pathogenic. Our results also suggest that wave action may influence the early colonization and homogeneous distribution of E. coli in beach sand and the subsequent release of sand or sediment-borne E. coli into lake water. Taken together, these results indicate that sand and sediment serve as temporal sources and sinks of human and waterfowl-derived E. coli that contribute to beach closures.
C
Catchment Microbial Dynamics: The Emergence of a Research Agenda
Authors: D. Kay, A. C. Edwards, R. C. Ferrier, C. Francis, C. Kay L. Rushby, J.
Watkins, A. T. McDonald, M. Wyer, J. Crowther, J. Wilkinson
Affiliations Hydrology and River Basin Dynamics Research Group, IGES, University of
Wales, Aberystwyth SY23 3DB, UK, Hydrology and River Basin Dynamics Research Group,
IGES, University of Wales, Aberystwyth SY23 3DB, UK, Earth and Biosphere Institute,
University of Leeds, Leeds LS2 9JT, UK, Hydrology and River Basin Dynamics Research
Group, IGES, University of Wales, Aberystwyth SY23 3DB, UK, Hydrology and River
Basin Dynamics Research Group, IGES, University of Wales, Aberystwyth SY23 3DB, UK
Source Progress in Physical Geography, 2007, 31(1): 59-76
Abstract: Parallel policy developments driven in the USA by the Clean Water Act and in Europe by the Water Framework Directive have focused attention on the need for quantitative information on the fluxes of faecal indicator bacteria in catchment systems. Data are required on point and diffuse source loadings, fate and transport of these non-conservative parameters, on the land surface, within soil systems, in groundwater, streams, impoundments and nearshore waters. This new information is needed by regulators to inform Total Maximum Daily Load estimates in the USA and Programmes of Measures in Europe both designed to prevent impairment of water quality at locations where compliance is assessed against health-based standards for drinking, bathing or shellfish harvesting. In the UK, the majority of catchment-scale activity in this field has been undertaken by physical geographers although microbial flux analysis and modelling has received much less attention from the research and policy communities than, for example, the nutrient parameters. This paper charts the policy drivers now operative and assesses the evidence base to support current policy questions. Finally, gaps and priority research questions are identified.
Classical Indicators in the 21st Century–Far and Beyond the Coliform
Author: Yates, Marylynn V
Source: Water Environment Research, March 2007, 79(3):279-286(8)
Abstract: Indicators have been used for many years to designate the microbiological quality of water. In 1914, the U.S. Public Health Service set a standard that required that drinking water show no evidence of coliform organisms (U.S. Treasury Department, 1914). Today, almost 100 years later, drinking waters in the United States must meet the standards established in the Total Coliform Rule, which requires that drinking water show no evidence of the presence of total coliform bacteria in 100 mL of water (U.S. EPA, 1989). However, as limitations with the use of coliforms have become apparent and the applications for indicator microorganisms have expanded, new indicators have been proposed and, in some cases, adopted, for specific purposes, as discussed in detail in a number of recent reports (i.e., National Research Council, 2004; World Health Organization, 2003).
D
Defining Acceptable Levels for Ecological Indicators: An Approach for
Considering Social Values
Authors Robyn L. Smyth, Mary C. Watzin and Robert E. Manning
Affiliations Rubenstein School of Environment and Natural Resources, University
of Vermont, Burlington, VT 05405, USA
Abstract Ecological indicators can facilitate an adaptive management approach, but only if acceptable levels for those indicators have been defined so that the data collected can be interpreted. Because acceptable levels are an expression of the desired state of the ecosystem, the process of establishing acceptable levels should incorporate not just ecological understanding but also societal values. The goal of this research was to explore an approach for defining acceptable levels of ecological indicators that explicitly considers social perspectives and values. We used a set of eight indicators that were related to issues of concern in the Lake Champlain Basin. Our approach was based on normative theory. Using a stakeholder survey, we measured respondent normative evaluations of varying levels of our indicators. Aggregated social norm curves were used to determine the level at which indicator values shifted from acceptable to unacceptable conditions. For seven of the eight indicators, clear preferences were interpretable from these norm curves. For example, closures of public beaches because of bacterial contamination and days of intense algae bloom went from acceptable to unacceptable at 7–10 days in a summer season. Survey respondents also indicated that the number of fish caught from Lake Champlain that could be safely consumed each month was unacceptably low and the number of streams draining into the lake that were impaired by storm water was unacceptably high. If indicators that translate ecological conditions into social consequences are carefully selected, we believe the normative approach has considerable merit for defining acceptable levels of valued ecological system components.
E
F
Fresh Submarine Groundwater Discharge from a Contaminated Beach Aquifer is
Enhanced During Neap Tide
Authors: de Sieyes, N R, Yamahara, K M, Boehm, A B
Affiliations: Stanford University, Environmental Engineering and Science Program Department
of Civil and Environmental Engineering Stanford, Stanford, CA 94305-4020, United States
Source: American Geophysical Union, 2007, 88(23)
Abstract: Experiments were carried out to assess the fortnightly effects of mixed semi-diurnal tides and tidally-induced aquifer over-height on the timing, magnitude, and quality of submarine groundwater discharge (SGD) from an unconfined beach aquifer impacted by septic tank effluent at Stinson Beach, California. Groundwater- and ocean elevations, salinity, and nutrient concentrations were monitored throughout a 14-day neap/spring cycle. A freshening of the surf zone coupled with an increase in nutrient concentrations was observed at neap tide and attributed to discharge of fresh, nutrient-rich groundwater during that part of the fortnight. Nutrient concentrations in the surf zone returned to near-offshore levels during the spring tide. Estimates of SGD were made with chemically- and physically-based methods. Fresh SGD was maximal during the neap tide although total SGD was maximal during the spring tide. An overheight of time-averaged piezometric head was observed in the aquifer near the beach face throughout the 14-day experiment. This over-height varied significantly with tidal range, thereby controlling the seaward hydraulic gradient across the fresh part of the aquifer and, thus, the flow of nutrient-rich fresh groundwater to the coastal ocean. We discuss the role of aquifer overheight in controlling submarine discharge of fresh groundwater and related non-point source pollution from unconfined aquifers in similar environments.
G
Genetic Relatedness of Escherichia coli Isolates in Interstitial Water
from a Lake Huron (Canada) Beach
Authors: Tatiana Kon, Susan C. Weir, E. Todd Howell, Hung Lee, and Jack T. Trevors
Affiliations: University of Guelph, Guelph, Ontario N1G 2W1, Canada, Ontario Ministry of the
Environment, 125 Resources Rd., Toronto, Ontario M9P 3V6, Canada
Source: Applied and Environmental Microbiology, March 2007, 73(69):1961-1967
Abstract: Research was undertaken to characterize Escherichia coli isolates in interstitial water samples of a sandy beach on the southeastern shore of Lake Huron, Ontario, Canada. A survey of the beach area revealed the highest abundance of E. coli in interstitial water of the foreshore beach sand next to the swash zone. Higher concentrations of E. coli (up to 1.6 x 106 CFU/100 ml of water) were observed in the interstitial water from the sampling holes on the beach itself compared to lake water and sediment. Repetitive extragenic palindromic PCR (REP-PCR) was used to characterize the genetic diversity of E. coli isolates from interstitial water samples on the beach. E. coli isolates from the same sampling location frequently exhibited the same REP-PCR pattern or were highly similar to each other. In contrast, E. coli isolates from different sampling locations represented populations distinct from each other. This study has identified a unique ecological niche within the foreshore area of the beach where E. coli may survive and possibly multiply outside of host organisms. The results are of interest as increasing concentrations of E. coli in recreational waters are often considered to be an indication of recent fecal pollution.
H
I
Identity, Politics, and the Beach: Environmental Activism in Surfers against
Sewage
Author: Belinda Wheaton a
Affiliation: a Chelsea School, University of Brighton. UK
Source: Leisure Studies, July 2007, 26(3): 279 - 302
Abstract: Academic accounts of leisure activities like surfing tend to emphasis their individualistic, hedonistic and commercialised qualities, seeing this as characteristic of leisure consumption in late capitalism; that culture is increasingly dominated by the market and attention is diverted from collective and political issues. Yet empirical research in such lifestyle sport cultures reveals a more complex and contradictory picture of leisure consumption. This paper examines the pressure group Surfers against Sewage (SAS), founded by surfers in Cornwall, England. It draws on subcultural media discourses about SAS and interviews with SAS members and personnel. Whilst acknowledging the limitations in the political significance and impact of SAS's activism, the paper argues that through their sport consumption, participants from a range of minority water sports cultures have formed a politicised trans-local collectivity based around a concern with their own localised environment, one which has become articulated into broader trans-national political issues. It is argued further that SAS is part of a broader wave of new social movements and direct action protest groups that gathered momentum in Britain in the mid to late 1990s. In such groups the politics of identity take centre stage. The paper therefore challenges us to rethink the meaning of political activism, and the capacity of leisure and sport to contribute to the politics of identity
Interaction and Influence of Two Creeks on Escherichia coli Concentrations of Nearby
Beaches: Exploration of Predictability and Mechanisms
Authors: Meredith B. Neversa,*, Richard L. Whitmana, Walter E. Frickb and Zhongfu Geb
Affiliations: a Great Lakes Science Center, Lake Michigan Ecological Research Station,
1100 N. Mineral Springs Road, Porter, IN 46304 USA, b Ecosystems Research Division, National Exposure
Research Laboratory, 960 College Station Road, Athens, GA 30605 USA
Source: Journal of Environmental Quality, 12 January 2007, 36: 1338-1345
Abstract: The impact of river outfalls on beach water quality depends on numerous interacting factors. The delivery of contaminants by multiple creeks greatly complicates understanding of the source contributions, especially when pollution might originate up- or down-coast of beaches. We studied two beaches along Lake Michigan that are located between two creek outfalls to determine the hydrometeorologic factors influencing near-shore microbiologic water quality and the relative impact of the creeks. The creeks continuously delivered water with high concentrations of Escherichia coli to Lake Michigan, and the direction of transport of these bacteria was affected by current direction. Current direction reversals were associated with elevated E. coli concentrations at Central Avenue beach. Rainfall, barometric pressure, wave height, wave period, and creek specific conductance were significantly related to E. coli concentration at the beaches and were the parameters used in predictive models that best described E. coli variation at the two beaches. Multiple inputs to numerous beaches complicates the analysis and understanding of the relative relationship of sources but affords opportunities for showing how these complex creek inputs might interact to yield collective or individual effects on beach water quality.
J
K
L
Luminex Detection of Fecal Indicators In River Samples, Marine Recreational Water,
And Beach Sand
Authors: Baums IB, Goodwin KD, Kiesling T, Wanless D, Diaz MR, Fell JW
Affiliation: Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine
and Atmospheric Science, University of Miami, Miami, FL 33149, USA.
Source: Marine Pollution Bulletin, May 2007, 54(5):521-36
Abstract: Research to understand and remediate coastal pollution is moving toward a multi-tiered approach in which traditional enumeration of fecal indicators is accompanied by molecular analysis of a variety of targets. Technology that rapidly detects multiple microbial contaminants would benefit from such an approach. The Luminex 100 system is a suspension array that assays multiple analytes rapidly in a single well of a microtiter plate. The ability of the system to simultaneously detect multiple fecal indicating bacteria in environmental samples was tested. Primer/probe sets were designed to simultaneously detect the following fecal indicators: the Bacteroides fragilis group, Enterococcus spp., Escherichia coli and Shigella spp., Bacteroides distasonis, and Ent. faecalis. Specificity and sensitivity of the Luminex probes was tested against laboratory cultures. In addition, sequencing, culture plate testing, and specificity testing with environmental isolates were steps taken to validate the function of the assay with environmental samples. Luminex response to cultures and to environmental samples was consistent with sequencing results, suggesting that the technology has the potential to simultaneously detect multiple targets for coastal water quality applications, particularly as progress is made to efficiently extract DNA from water and sediment matrices.
M
N
Nowcasting and Forecasting Beach Bacteria Concentration Using EPA's
Virtual Beach Software
Authors Frick, W E, Ge, Z
Affiliation U.S. Environmental Protection Agency, 960 College Station Road, Athens,
GA 30605, United States
Source American Geophysical Union (AGU), 2007
Abstract: Beaches in the United States of (North) America are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on water samples that typically require at least 18 hours to analyze. This persistence approach, or model, often leads to erroneous decisions due to the great variability in bacterial concentrations. Beaches are closed when they could be open and vice versa, their true status unknown until the next day. Studies show that mathematical models based on multi-variable linear regression (MLR) principles can produce better estimates, or nowcasts, using real-time explanatory variables, such as turbidity, cloud cover, and rainfall. To make such models generally available, the Environmental Protection Agency (EPA) is developing a program called Virtual Beach (VB). VB is public-domain software for developing site-specific predictive models. It features capabilities that make it possible with reasonable effort to develop, and compare the performance of, static and dynamic MLR models. The results of tests on 2006 Huntington Beach, Lake Erie beach data are presented. In addition to nowcasting, the work begins to address the question, can weather and water forecasts be used to forecast beach conditions in advance? A preliminary affirmative answer is provided based on an analysis of the Huntington Beach data, with weather forecasts for nearby Cleveland-Hopkins international airport, and NOAA lake condition forecasts. We encourage those engaged in beach monitoring and management to request VB, applying the nowcast and forecast models developed with it to their locations of interest. Disclaimer: Although this work was reviewed by EPA and approved for presentation, it may not necessarily reflect official Agency policy.
O
Occurrence of Antibiotic Resistance in Escherichia coli from Surface
Waters and Fecal Pollution Sources near Hamilton, Ontario
Author: Edge, Thomas A; Hill, Stephen
Source: Canadian Journal of Microbiology/Revue Canadienne de Microbiologie Vol. 51,
no. 6, pp. 501-505. Jun 2005.
Abstract: Antibiotic resistance was examined in 462 Escherichia coli isolates from surface waters and fecal pollution sources around Hamilton, Ontario. Escherichia coli were resistant to the highest concentrations of each of the 14 antibiotics studied, although the prevalence of high resistance was mostly low. Two of 12 E. coli isolates from sewage in a CSO tank had multiple resistance to ampicillin, ciprofloxacin, gentamicin, and tetracycline above their clinical breakpoints. Antibiotic resistance was less prevalent in E. coli from bird feces than from municipal wastewater sources. A discriminant function calculated from antibiotic resistance data provided an average rate of correct classification of 68% for discriminating E. coli from bird and wastewater fecal pollution sources. The preliminary microbial source tracking results suggest that, at times, bird feces might be a more prominent contributor of E. coli to Bayfront Park beach waters than municipal wastewater sources.
Occurrence of human adenoviruses at two recreational beaches of the
great lakes.
Authors: Xagoraraki I, Kuo DH, Wong K, Wong M, Rose JB.
Source: Applied Environmental Microbiology. 2007 Dec;73(24):7874-81. Epub 2007 Oct 12.
Publisher: Department of Civil and Environmental Engineering, Michigan State University,
A136 Engineering Research Complex, East Lansing, MI 48824, USA.
URL: http://www.ncbi.nlm.nih.gov/pubmed/17933924?ordinalpos=3&itool=EntrezSystem2.P Entrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
ABSTRACT: Human adenoviruses (HAdVs) have been related to several waterborne diseases such as acute gastroenteritis, conjunctivitis, and respiratory illness, and it has been shown that an important human exposure pathway is through recreational waters. However, HAdV occurrence at recreational freshwater beaches has not been previously investigated. In this study, a total of 58 water samples were collected from two recreational beaches on Lake Michigan (i.e., Silver Beach and Washington Park Beach) during the summer of 2004. Occurrences of HAdVs in these lake samples were determined using two hexon-based real-time PCR assays (one for monitoring all 51 serotypes of HAdVs and another for specifically detecting F species HAdVs, i.e., serotypes 40 and 41) and compared to an integrated cell culture (ICC) PCR method. The real-time PCR results showed that 8 of 30 Silver Beach samples and 6 of 28 Washington Park Beach samples contained HAdVs, and F species HAdVs were detected in three of these positive samples. The concentrations of HAdVs ranged from (1.7 +/- 0.7) x 10(1) to (3.4 +/- 0.8) x 10(2) and from (7 +/- 2) x 10(0) to (3.8 +/- 0.3) x 10(3) virus particles/liter for Silver Beach and Washington Park Beach, respectively. F species HAdVs were detected at levels ranging from (4.8 +/- 0.8) x 10(1) to (4.6 +/- 1.5) x 10(2) virus particles/liter. Approximately 60% of the ICC-PCR analyses agreed with the real-time PCR results. This study revealed the occurrence of HAdVs at Lake Michigan recreational beaches. Given the potential health risks, further assessment regarding sources, virus transport, and survival is needed to improve the safety of the region.
P - Q
Persistence, Dissipation, and Activity of Escherichia Coli O157:H7 Within Sand
and Seawater Environments
Authors Williams, A. Prysor, Avery, Lisa M., Killham, Ken, Jones, David L.
Affiliations School of the Environment and Natural Resources, University of Wales,
Bangor, Gwynedd, UK, School of Water Sciences, Cranfield University, Cranfield,
Bedford, UK; and Department of Plant and Soil Science, University of Aberdeen, Aberdeen, UK
Source FEMS Microbiology Ecology, April 2007, 60(1): 24-32(9)
Abstract Runoff from agricultural land into watercourses may transport and deposit animal-derived waste contaminated with Escherichia coli O157:H7 onto beaches, which may in turn lead to human infection. To simulate contamination, freshwater mixed with cattle slurry containing E. coli O157:H7 was added to sand from three recreational beaches. The sand was then maintained in a dry state (nontidal) or subjected to a repeated seawater tidal simulation. The pathogen could still be recovered from all sands by day 5. Although survival of the pathogen did not statistically vary between sands of different origin under nontidal conditions, significant differences in numbers occurred between sands when subject to tidal simulation. In the tidal simulations, a considerable proportion of the E. coli O157:H7 rapidly dissipated from sand into the seawater. In a separate experiment, the activity of bioluminescent (lux-marked) E. coli O157:H7 cells was monitored in various mixtures of contaminated runoff water and seawater over 5 days. Pathogen activity declined with increasing seawater concentration; however, cells remained viable in all treatments over the 5-day period. The addition of nutrients to water rapidly increased pathogen activity in all treatments. Our findings highlight the resilience of E. coli O157:H7 in aquatic and marine environments.
The Potential for Beach Sand to Serve as a Reservoir for Escherichia
coli and the Physical influences on Cell Die-off
Authors Beversdorf, L.J., Bornstein-Forst, S.M., McLellan, S.L.
Source: Journal of Applied Microbiology, May 2007, 102(5): 1372-1381(10)
Abstract: The Escherichia coli burden at a Great Lakes urban beach was evaluated during the summer months to determine if sand served as a reservoir for E. coli, and if there was evidence of cell replication in situ. Field and laboratory studies investigated the effects of moisture, temperature and UV on E. coli densities in the sand.
Methods and Results: Sand samples (n=481) were collected across three distinct transects of the beach, the top, a middle streamline, and the berm, over 15 sample days. The highest levels were found in the middle streamline, which was affected by stormwater discharge from nearby outfalls and roosting gulls; daily geometric mean levels of these seven sites ranged from 6700 to 40900CFU per 100g of sand. Escherichia coli levels were greatest in samples with moisture levels between 15% and 19%, and were significantly higher than 0-4 and 20-24% ranges (P‹0•05). Pre- and post-rain samples at the beach demonstrated an increase in E. coli levels nearly 100-fold within 30min, suggesting sand washout as a major mechanism for loading of E. coli into the beach waters. Rep PCR analysis of 160 isolates obtained from eight sites demonstrated that 21% of the isolates fell into one of the six clonal patterns, suggesting that bacteria may be able to replicate and possibly colonize beach sand. Sand field plots inoculated with E. coli cells containing pGFPuv that expresses GFP (green fluorescent protein) as a marker showed an initial two- to 100-fold increase at 24h, depending on the temperature condition. The sand appeared to provide considerable protection from UV exposure as no significant difference was seen in cell densities within the first 2-4cm of sand between exposed and unexposed plots (P‹0•05).
Conclusions: Beach sand may act as a reservoir for E. coli. Replication of cells appears to be one possible contributing factor to the persistently high levels, as indicated by both field studies and laboratory studies, and warrants further investigation. Moisture content of sand may also be a determinant of cell persistence in the sand environment.
Significance and Impact of the Study: Escherichia coli is used as an indicator organism for faecal pollution at most Great Lakes coastal beaches; therefore, a better understanding of how E. coli might survive, or possibly replicate, in the environment would improve interpretation of beach monitoring results.
Prevalence of yeasts in beach sand at three bathing beaches in South Florida
Authors: C. Vogela, A. Rogersonb, S. Schatzc,
H. Laubachd, A. Tallmane and J. Fellf
Affiliations: aSUNY, Marine Sciences Research Center, Stony Brook, NY 11794-5000, USA, bCollege
of Science, Marshall University, One Marshall Drive, Huntington, WV 25755, USA, cCollege of Optometry,
Health Profession Division of Nova Southeastern University, 3200 S University Drive, Ft. Lauderdale,
FL 33328, USA, dOceanographic Center of Nova Southeastern University, 8000 N, Ocean Drive, Dania Beach,
FL 33004, USA, eCollege of Medical Sciences, Health Profession Division of Nova Southeastern University,
3200 S University Drive, Ft. Lauderdale, FL 33328, USA, fSchool of Marine and Atmospheric Science,
University of Miami, 4600 Rickernbacker Causeway, Miami, FL 33149, USA
Source: Water Research, May 2007, 41(9):1915-1920
Abstract: The abundance and types of yeasts in the wet and dry sand of three recreational beaches in South Florida were determined. Samples were collected on 17 occasions between August 2001 and July 2002. After analyzing 102 sand samples, a total of 21 yeast species were identified by molecular methods. These isolates comprised four Basidiomycetes and 17 Ascomycetes and included eight species that had previously been reported from humans. The most frequently encountered yeasts were Candida tropicalis and Rhodotorula mucilaginosa. A greater diversity of species (16 species) was found in the dry sand above the high tide mark compared with the wet sand in the intertidal zone (11 species). Densities were also highest in the dry sand relative to wet sand (20-fold higher at Hobie beach, 6-fold higher at Fort Lauderdale Beach and 1.3-fold higher at Hollywood beach). There were no clear temporal patterns in the data and overall densities were greatest at the busiest bathing beach (Hobie Beach) where total yeasts averaged 37,720 cfu 100 g–1 dry sand and 1852 cfu 100 g–1 in the wet sand. This concentration of yeast was significantly higher than populations at the less populated beaches. Fort Lauderdale beach had a mean count of 4130 cfu 100 g–1 dry sand and 705 cfu 100 g–1 in the wet sand while the least populated beach, Hollywood Beach averaged 1945 cfu 100 g–1 dry sand and 1483 cfu 100 g–1 wet sand. While definitive statements cannot be made, high levels of yeasts may have a deleterious bearing on human health and the presence of such a diverse aggregation of species suggests that yeasts could have a role as indicators of beach health.
R
Regional Public Health Cost Estimates of Contaminated Coastal Waters: A Case Study
of Gastroenteritis at Southern California Beaches
Authors: * Given, S, Pendleton, L, Boehm, A
Affiliations: Department of Environmental Health Sciences, Environmental Science and Engineering
Program, 46-071A Center for Health Sciences, University of California, Los Angeles, CA 90095,
United States, Environmental Water Studies, Department of Civil and Environmental Engineering,
Stanford University, Stanford, CA 94305-4020, United States
Source: Environmental Science Technology, 2007, 40 (16): 4851 -4858
Abstract: We present estimates of annual public health impacts, both illnesses and cost of illness, attributable to excess gastrointestinal illnesses caused by swimming in contaminated coastal waters at beaches in southern California, USA. Beach-specific enterococci densities are used as inputs to two epidemiological dose-response models to predict the risk of gastrointestinal illness at 28 beaches spanning 160 km of coastline in Los Angeles and Orange Counties. We use attendance data along with the health cost of gastrointestinal illness to estimate the number of illnesses among swimmers. We estimate that between 627,800 and 1,479,200 excess gastrointestinal illnesses occur at beaches in Los Angeles and Orange Counties each year. Using a conservative health cost of gastroenteritis, this corresponds to an annual economic loss of $21 or $51 million depending upon the underlying epidemiological model used (in year 2000 dollars). Results demonstrate that improving coastal water quality could result in a reduction of gastrointestinal illnesses locally and a concurrent savings in expenditures on related health care costs.
S
Solar and Tidal Modulations of Fecal Indicator Bacteria in Coastal Waters
at Huntington Beach, California
Authors: Seo Jin Ki1, Semsi Ensari2 and Joon Ha Kim3
Affiliations: Department of Environmental Science and Engineering, Gwangju Institute of
Science and Technology (GIST), Gwangju, 500-712, Korea, The Henry Samueli School of Engineering,
University of California, Irvine, California 92697, USA, Department of Environmental Science and
Engineering, Gwangju Institute of Science and Technology (GIST), Center for Water Research, GIST,
Gwangju, 500-712, Korea
Source: Environmental Management, 19 April 2007, 39(6):867-875
Abstract: The coastal waters at many beaches in California and the United States are afflicted with fecal pollution, which poses a health risk for people exposed to the water through recreational activities such as swimming, surfing, and diving. Identifying sources of pollution is complicated by oceanographic transport/mixing processes and the nonconservative behavior of microorganisms exposed to sunlight and hostile marine conditions. This article investigates the variation of fecal indicator bacteria (FIB) concentrations in the surf zone and the adjacent coastal marsh by applying autocorrelation and cross-correlation analyses that illustrate solar and tidal modulations. A steady state bioreactor model was developed to explain solar inactivation in the surf zone, whereas a dynamic model was applied to explain tidally influenced disturbances in the coastal marsh. These models applied to intensive monitoring datasets on FIB and environmental variables have provided insights into the biologic and physical processes controlling coastal water quality, specifically the influence of sunlight and tides on bacterial levels.
Some Statistical Issues Related To Multiple Linear Regression Modeling Of Beach
Bacteria Concentrations
Authors: Zhongfu Gea, and Walter E. Frickb
Affiliations: aNational Research Council, U.S. Environmental Protection Agency, 960 College
Station Road, Athens, GA 30605-2720, USA, bU.S. Environmental Protection Agency, Ecosystems
Research Division, 960 College Station Road, Athens, GA 30605-2720, USA
Source: Environmental Research, March 2007, 103(3):358-364
Abstract: As a fast and effective technique, the multiple linear regression (MLR) method has been widely used in modeling and prediction of beach bacteria concentrations. Among previous works on this subject, however, several issues were insufficiently or inconsistently addressed. Those issues include the value and use of interaction terms, the serial correlation, the criteria for model selection, and model assessment. The present work shows that serial correlations, as often present in sequentially observed data records, deserve full attention from the modeler. The testing and adjustment for the time-series effect should be implemented in a statistically rigorous framework. The R2 and Cp-statistic as joint criteria are recommended for the model selection process, while using the t-statistics associated with the full model is erroneous. During model selection, using interaction terms can often help to decrease the bias in reduced models, although the resulting improvement in the numerical performance may be limited. For the assessment of the model predictive capacity, which is different from testing the goodness of fit, a comprehensive set of statistics are advocated to allow for an objective evaluation of different models. Results obtained from the data at Huntington Beach, OH, show that erroneous conclusions could be drawn if only the model R2 and the count of type I and type II errors are considered. In this sense, several previous works deserve further investigation.
This work was partially supported by an interagency agreement between the NOAA Ocean and Human Health program and USGS, Columbus, Ohio through the USGS Michigan Water Science Center, Lansing, Michigan.
Spatio-Temporal Variability in Fecal Indicator Bacteria Concentrations at Huntington Beach:
Connections to Physical Forcing
Authors: * Rippy, M A, Feddersen, F, Leichter, J, Omand, M, Moore, D F, McGee, C, Franks, P J
Affiliations: Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0208, United
States, Orange County Public Health Laboratory, 1729 West 17th St., Santa Ana, CA 92706, United States,
Orange County Sanitation District, 10844 Ellis Ave., Fountain Valley, CA 92708, United States
Source: American Geophysical Union, 2007, 88(23)
Abstract: Two major factors determine the spatial and temporal distributions of fecal indicator bacteria (FIB) at a given beach: local circulation & mixing patterns, and bacterial inactivation rates. High frequency and spatial resolution bacterial sampling combined with measurements of physical processes can be used to infer inactivation rates, enabling differentiation between dilution & mortality as factors driving variability in nearshore FIB abundance. A FIB sampling experiment (HB06) took place on 16 October 2006, at Huntington State Beach, a site selected due to its persistent problems with FIB pollution. Water samples were taken at 20-minute intervals (from 6:50am to 11:50am) at ten locations; four in an alongshore transect spanning 1 km at the shoreline, and the remainder in a 300-m long cross-shore transect. All samples were analyzed for FIB concentration (Total Coliforms, E. coli & Enterococci) and, for a subset, species level Enterococcus composition was determined. As part of the HB06 experiment, currents, temperature, waves, and chlorophyll fluorescence were measured simultaneously in the cross-shore direction with rapid CTD casts 300 m offshore. Results indicate that E. coli and Enterococcus concentrations exhibit exponential decreases with time, with smaller decay rates associated with depth and with sites in the Talbert Marsh and Santa Ana River. FIB concentrations are also noticeably lower farther offshore (300 m). Spatio-temporal patterns in FIB concentration will be presented in conjunction with the nearshore physical data allowing the relationship between physical dynamics and biological variability to be addressed.
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Water Quality Indicators and the Risk of Illness at Beaches with
Nonpoint Sources of Fecal Contamination
Authors Colford, John M. Jr., Wade, Timothy J., Schiff, Kenneth C., Wright,
Catherine C., Griffith, John F., Sandhu, Sukhminder K, Burns, Susan [S]; Sobsey,
Mark [P]; Lovelace, Greg [P]; Weisberg, Stephen B.
Source Epidemiology, January 2007, 18(1): 21-22
Abstract: Background: Indicator bacteria are a good predictor of illness at marine beaches that have point sources of pollution with human fecal content. Few studies have addressed the utility of indicator bacteria where nonpoint sources are the dominant fecal input. Extrapolating current water-quality thresholds to such locations is uncertain.
Methods: In a cohort of 8797 beachgoers at Mission Bay, California, we measured baseline health at the time of exposure and 2 weeks later. Water samples were analyzed for bacterial indicators (enterococcus, fecal coliforms, total coliforms) using both traditional and nontraditional methods, nie, chromogenic substrate or quantitative polymerase chain reaction. A novel bacterial indicator (Bacteroides) and viruses (coliphage, adenovirus, norovirus) also were measured. Associations of 14 health outcomes with both water exposure and water quality indicators were assessed.
Results: Diarrhea and skin rash incidence were the only symptoms that were increased in swimmers compared with nonswimmers. The incidence of illness was not associated with any of the indicators that traditionally are used to monitor beaches. Among nontraditional water quality indicators, associations with illness were observed only for male-specific coliphage, although a low number of participants were exposed to water at times when coliphage was detected.
Conclusions: Traditional fecal indicators currently used to monitor these beaches were not associated with health risks. These results suggest a need for alternative indicators of water quality where nonpoint sources are dominant fecal contributors.
