Recreational Water Use Research Articles

Summer at the beach: spatio-temporal patterns of white shark occurrence along the inshore areas of False Bay, South Africa

BackgroundUnderstanding white shark (Carcharodon carcharias) habitat use in coastal areas adjacent to large cities, is an important step when formulating potential solutions to the conservation conflict that exists between humans and large predatory sharks. In this study, we present the findings of a 2.5-year study of white shark occurrence and movement patterns adjacent to the City of Cape Town in False Bay, South Africa, with a focus on spring and summer months. Fifty-one white sharks were monitored annually at three offshore and twelve inshore sites by VR2 acoustic receivers, over 975 days from 1 May 2005 to 31 December 2007.ResultsOccurrence patterns at inshore sites during spring and summer were analysed using a generalized additive mixed model (GAMM) with a spatial term (longitude, latitude), time of day and year included as explanatory variables for site use. We found that sharks occurred more frequently at inshore sites along the northern and northwestern shores, compared to the rest of the bay, and they transitioned most frequently between four adjacent beach sites that encompass the most popular recreational water use areas in Cape Town. There was significant diel variation, with higher shark occurrence around midday, and a peak in shark occurrence in 2005, when human-shark interactions also peaked. However, we found no effect of shark size on occurrence patterns at inshore sites.ConclusionsWhite sharks showed the highest levels of occurrence at specific inshore sites between Muizenberg and Strandfontein beach, and thus inclusion of these sites within False Bay’s marine protected area (MPA) network or recognition as Ecological or Biological Significant Areas (EBSAs) should be a future consideration. These insights into white shark habitat use at inshore sites in False Bay are important for successfully applying the principles of marine spatial planning (MSP) and for making science-based policy decisions. Furthermore, this information can be used to reduce potential shark-human conflict by incorporating it into future shark safety education campaigns.

Occurrence, genotyping, and health risk of Cryptosporidium and Giardia in recreational lakes in Tianjin, China

Cryptosporidium and Giardia are critical parasites in the etiology of diarrhea worldwide, and often cause waterborne outbreaks. The presence of Cryptosporidium and Giardia in recreational lakes was investigated with molecular characterization, and a comprehensive quantitative microbial risk assessment (QMRA) of protozoan infections was performed, considering multiple exposure pathways, differences in age, sex, and disease severity, and the genotypes of the protozoa. Forty-three (82.7%) and 51 (98.1%) water samples were positive for Cryptosporidium oocysts and Giardia cysts, respectively, with average counts of 3.65 oocysts/10 L and 12.58 cysts/10 L, respectively. Six Cryptosporidium species and three Giardia lamblia assemblages were confirmed with molecular analyses. The protozoan concentration was significantly associated with water turbidity, but not with the total coliform numbers. Swimming in the lakes entailed the highest incidence risk of 5.72 × 10−4 per person per year (pppy) (95% confidence interval (CI): 0.03–43.33 × 10−4) for Cryptosporidium and 4.04 × 10−4 pppy (95% CI: 0.01–32.66 × 10−4) for Giardia, whereas wading entailed the lowest risk (2.20 × 10−4 and 1.70 × 10−4 pppy, respectively). The annual burdens attributable to recreational-water-associated cryptosporidiosis and giardiasis were 3.44 (95% CI: 0.04–23.51) and 1.81 (95% CI: 0.01–12.96) disability-adjusted life years per 1,000,000 individuals per year, respectively. Children were more likely to have an individual disease burden than adults, and males were more likely than females. Sensitivity analysis highlighted the great importance of controlling the proportion of exposed individuals and reducing the frequency of exposure. The methodology and results of this study will allow us to better evaluate and reduce the burden of Cryptosporidium and/or Giardia infections associated with recreational water use in China and other countries.

Temporal trends in Giardia occurrence in the Grand River and surrounding tributaries, Waterloo, Ontario (2005-2013), a retrospective analysis of surveillance data.

Giardia contamination in the Grand River Watershed (south-western Ontario, Canada) was monitored from 2005 to 2013 as part of FoodNet Canada. Our study objectives were to describe the temporal pattern of Giardia occurrence and determine whether water quality parameters and bacterial indicators could act as effective markers for Giardia occurrence. Water samples were collected monthly from the Grand River near a drinking water intake point (2005-2013) and also collected intermittently from other areas in the watershed during the study period. Samples were tested for Giardia cysts using the US EPA method 1623. Samples were also tested for chemical and microbial water quality indicators. Univariable and multivariable linear regression models were built to examine whether temporal, water quality and bacterial indicators were associated with Giardia cyst concentration. Giardia cysts were identified in 89% of samples (n=228), with highest measured concentrations downstream of a waste water treatment plant outfall. Year and season were found to be predictors for Giardia occurrence. Concentrations were significantly higher in the winter and fall compared to the summer, and significantly higher in 2007 compared to other study years. After controlling for season, year and sampling location, dissolved oxygen was the only variable significantly associated with Giardia cyst concentration. Seasonal peaks in Giardia cyst concentrations in samples collected near the intake for the drinking water plant did not align with the seasonal peak in human Giardiasis cases in this region that are reported annually by public health authorities. This suggests that the risk of contracting Giardiasis from treated drinking water in this community is possibly low when the treatment plant is functioning adequately. Instead, waterborne exposure is likely the result of seasonal behaviours surrounding recreational water use. Therefore, the collective findings of our study are important to help inform future risk management studies and guide public health protection policies.

Assessment of the microbiological quality of recreational waters: indicators and methods

The microbiological quality of recreational waters (RW) has been assessed through the use of microbial indicators. Usually, three typical fecal bacteria, namely fecal coliforms, Escherichia coli and Enterococcus spp., are deemed by legislation and regulatory agencies for routine monitoring of the fecal contamination in RW. However, these traditional indicators have some limitations, as they underestimate health risks and do not determine the sources of contamination. Currently, the increasing concern with the minimization of human health risks associated with recreational water use and the protection of water resources outweigh the actual normative perspective. The potentials and limitations of conventional and alternative fecal contamination detection systems must be carefully evaluated, taking into account the specificities of each recreational water body and the natural or anthropogenic sources of environmental variability. The careful choice of analysis for detection and quantification of indicators in the light of their potential and shortcomings is of major importance for the timely evaluation of risks and implementation of strategies that effectively protect users and preserve water quality. This paper presents a critical literature review of the traditional and innovative methodologies for the analysis of fecal indicators in recreational water and intends to discuss their contribution for the management of the microbiological quality and safety of leisure surface waters.

A review of water quality policies in relation to public good benefits and community engagement in rural Ireland

Abstract This paper examines current recreational water use in the rural landscape in Ireland and reviews current EU policies and national regulations aimed at protecting water quality and the wider environment under agri-environmental schemes. Specifically, we review policy instruments that protect water for recreational use, their impacts and the challenges they pose for rural development against current requirements to increase public awareness and participation. In Ireland, there is limited experience in public participation in water quality protection and restoration and we highlight how this can be addressed by focussing on the specific contribution of water quality in rural areas in relation to the provision of recreational ecosystem services. These services provide the infrastructure for much of Ireland’s rural tourism sector. In this context, emerging participatory approaches to policy implementation are also assessed as national and local government prioritise community engagement for the second cycle under the EU Water Framework Directive.

Технические решения по предотвращению теплового загрязнения водоемов в пределах урболандшафта

Objective: The development and scientific substantiation of technical solutions for prevention thermal pollution of cooling pond of power facilities. Methods: Patent study, methods of system analysis. Results: Found that cooling ponds in which discharged heated water from electric power facilities, leading to thermal pollution. In connection with which the waters become unfit for housing and communal services, namely drinking and domestic water supply and recreational water use. The existing technical solution for preventing thermal pollution of water bodies have a number of drawbacks, namely low reliability due to the complexity and bulkiness of the structure; limited functionality due to not fully using the heat medium and long cold water. On the basis of the patent study of existing methods of reducing thermal pollution, the developed heat exchanger heated waters of power objects (patent RU № 134621). Designed heat exchanger characterized by enhanced functionality available ways to prevent thermal pollution due to the use of thermal energy of the heated waters of power plants for heating of cold water and correspondingly cooling the heated waters. Practical importance: The proposed by authors technical solution allows utilizing the heat energy of the heated waters of power facilities before discharge into cooling ponds. Thus, the heat exchanger prevents thermal pollution of the reservoir and consequently provides a desired level of water quality for water supply and supplies the consumers with warm water, i. e., contributes to several tasks of housing and communal services.

The Landscape/geographical Method of Spatial Assessment of Water Resources Potential for the Purposes of Recreational Use

Provisions of the landscape/geographical method of spatial assessment of a water resources potential for recreational water use are presented. The water resources potential has been considered as a set of water and around-water conditions that determine principal possibility and its degree for the water bodies’ and coastline use for water recreation Spatial boundaries of the water resources potential spreading at the regional level have been identified on the basis of summing up and analysis of traditional methods of the water resources recreational assessment. Concurrently the list and indicators of the integral assessment criteria have been developed. Areas with similar conditions for recreational water use have been proposed to be considered in connection with the landscape structure and to limit them by the floodplain and valleys landscapes. Physiognomic, functional, and psychological assessment criteria are presented as integrated physical/geographic characteristics coupled with the data of the landscape, topographic and geological/geomorphological maps. Testing and approval of the method have been carried out with the Altay Kray territory as a study case. Partial criterial and integrated assessments of the water resources potential have been performed for this region. The assessment values were depicted by mapping. Correspondence of the calculated outputs to the actual regional situation was confirmed by the expert review.

Multi-day diurnal measurements of Ti-containing nanoparticle and organic sunscreen chemical release during recreational use of a natural surface water

A recreational water system was monitored for release of both mineral and organic sunscreen constituents for the first time.

Spatiotemporal Variability of Contaminants in Lake Water and Their Risks to Human Health: A Case Study of the Shahu Lake Tourist Area, Northwest China

Shahu Lake is a well-known tourist lake in Ningxia, northwest China. This study analyzed the general hydrochemical characteristics of the lake water to determine the spatiotemporal variability of contaminants and to assess the potential health risk associated with the surface water. Lake water was monitored at three stations each month throughout 2013. Samples were analyzed for pH, total dissolved solids, temperature, EC, major ions (Na+, K+, Ca2+, Mg2+, SO4 2−, Cl−, HCO3 −, and CO3 2−), ammonia nitrogen (NH4-N), fluoride (F−), phenol, and heavy metals (As, Hg, and Cr6+). The results suggest that Na+ is the dominant cation in the lake water, and Cl− and SO4 2− are the dominant anions, resulting in a primary water type of Cl·SO4–Na. Contaminant levels (NH4-N, F−, As, Hg, Cr6+, and phenol) vary through time and space (spatiotemporal variations). As and F− are high in the summer season; Cr6+ and Hg do not significantly change over the year; and the NH4-N and phenol concentrations also remain relatively stable. Concentrations of all these substances are within the acceptable limits for recreational water use (1.5, 1.5, 0.1, 0.001, 0.05, and 0.01 mg/L for NH4-N, F−, As, Hg, Cr6+, and phenol, respectively). An assessment model recommended by the Ministry of Environmental Protection of the P.R. China was used in the study to conduct the health risk assessment. While workers do experience higher non-carcinogenic and carcinogenic risks than tourists, the risks are low and negligible. As and Cr6+ contribute the most to total carcinogenic and non-carcinogenic risks.

Two decades of system-based hygienic–microbiological research in Swist river catchment (Germany)

A multidisciplinary research project series has sought to identify and better understand multiple hygienic–microbiological and chemical contaminations from both point sources and diffuse pollution to contribute to the improvement in surface water quality. In the catchment area of the river Swist (Germany), municipal sewage treatment plants were investigated, followed by event-based investigation of combined sewer overflows, rainwater retention basins and diffuse pollution by surface and subsurface run-off as well as drain pipes. Recently, retention soil filters installed between stormwater storage basins and receiving surface waters in order to provide further treatment of combined sewer overflows were investigated. Geographical information system analysis helped to examine the data in their temporal and spatial dimensions. A model for calculating microbial and chemical loads within a catchment area was developed (“Swistbox”) which provides an efficient tool for risk assessment. Nearly two decades of investigation has demonstrated that several elements of the landscape’s water balance account for surface water pollution from both diffuse and point sources. Depending on land cover characteristics, wastewater technology and the proportion of wastewater as compared to total river water flow, a source can vary in its importance for the catchment area. The findings can be applied for sustainable and health-sensitive catchment management in relation to recreational or agricultural water use as well as ecological aspects.

Human-Associated Bacteroides spp. and Human Polyomaviruses as Microbial Source Tracking Markers in Hawaii.

This study represents an in-depth characterization of microbial source tracking (MST) markers in Hawaii. The distribution and concentrations of HF183TaqMan and HPyV markers in human and animal fecal samples and in wastewater, coupled with decay data obtained from sunlight-exposed and unexposed microcosms, support the concurrent application of HF183TaqMan and HPyV markers for sewage contamination detection in Hawaii waters. Both markers are more conservative and more specific markers of sewage than fecal indicator bacteria (enterococci and Escherichia coli). Analysis of HF183TaqMan (or newer derivatives) is recommended for inclusion in future epidemiological studies concerned with beach water quality, while better concentration techniques are needed for HPyV. Such epidemiological studies can be used to develop new recreational water quality criteria, which will provide direct information on the absence or presence of sewage contamination in water samples as well as reliable measurements of the risk of waterborne disease transmission to swimmers.

An exploratory study of the implementation of admission standards (child:guardian ratios) in Ontario's Class A public pools

Admission standards or specific child:guardian ratios for public pools have been endorsed and promoted by the Ontario Ministry of Health and Long Term Care (MOHLTC) to prevent recreational water injuries and fatalities. However, the voluntary adoption of these admission standards in Ontario has not been evaluated. Therefore, the aim of this study was to explore the implementation of these admission standards in Class A public pools. An online survey was developed and disseminated to Class A public pool operators in Ontario. Frequency distributions were used to describe the results. All respondents have some form of admission standards integrated into their operations, with 68% using child:parent ratios that exceed the minimum MOHLTC's recommendations. The majority of operators (87%) felt that admission standards have a positive impact and there were no known increases in water-related incidents post-implementation. Many owners/operators (78%) would support their enactment into the pool regulations. The findings from this study highlight the promise of utilizing admission standards to prevent or, at the least reduce, the burden of injury related to recreational water use in Ontario. While the results are encouraging, it is recommended that further research be conducted as this was an exploratory study only.

The beach bum survey: investigating the association between surfing and faecal carriage of antibiotic resistant bacteria

Introduction: Antibiotic resistant bacteria (ARB) represent one of the greatest health threats to public health. Much research has been done on how people acquire ARB, particularly in healthcare settings. Very little has been done on the role natural environments play in the spread of ARB to people. Coastal waters are regularly polluted by sewage carrying many ARB, and the densities detected have been high enough to pose an exposure risk to surfers when they swallow seawater. Methods: In a cross-sectional study, we collected rectal swabs from 273 healthy adults in the UK: 143 regular surfers and 130 non-surfers. We screened the swabs for enteric coliforms resistant to two clinically important antibiotics: cefotaxime, and meropenem. Polymerase chain reaction was used to determine whether resistant colonies were carrying the clinically important plasmid-borne resistance genes responsible for the observed phenotypes, such as blaCTX-M, which encodes resistance to multiple beta-lactam antibiotics. Results: While phenotypically resistant bacteria were equally prevalent in both surfers and non-surfers, surfers were at an increased risk of carrying CTX-M-bearing bacteria compared to non-surfers (risk ratio = 4.09, 95% confidence interval 1.02 – 16.4). Conclusions: Thus surfing was associated with the carriage of gut bacteria harbouring CTX-M genes, which are responsible for multi-drug resistance in bacteria. This is the first study to investigate the association between recreational use of coastal waters and gut colonisation by ARB. However determining the causal nature of this relationship will require further work. Nevertheless, surfers could be contributing to the prevalence of ARB in the wider population. Identifying environmental transmission pathways will be critical to understanding the spread of ARB, and thus essential in developing effective mitigation strategies to reduce their worrying proliferation amongst the wider public.

Evaluation of Glass Wool Filters and Hollow-Fiber Ultrafiltration Concentration Methods for qPCR Detection of Human Adenoviruses and Polyomaviruses in River Water.

Pathogenic human viruses cause over half of gastroenteritis cases associated with recreational water use worldwide. They are difficult to concentrate from environmental waters due to low numbers and small sizes. Rapid enumeration of viruses by quantitative polymerase chain reaction (qPCR) has the potential to improve water quality analysis and risk assessment. However, capturing and recovering these viruses from environmental water remain formidable barriers to routine use. Here, we compared the recovery efficiencies of human adenoviruses (HAdVs) and human polyomaviruses (HPyVs) from 10-L river water samples seeded with raw human wastewater (100 and 10 mL) using hollow-fiber ultrafiltration (HFUF) and glass wool filter (GWF) methods. The mean recovery efficiencies of HAdVs in river water samples through HFUF were 36 and 86 % for 100 and 10 mL of seeded human wastewater, respectively. In contrast, the estimated mean recovery efficiencies of HAdVs in river water samples through GWF were 1.3 and 3 % for 100 and 10 mL seeded raw human wastewater, respectively. Similar trends were also observed for HPyVs. Recovery efficiencies of HFUF method were significantly higher (P < 0.05) than GWF for both HAdVs and HPyVs. Our results clearly suggest that HFUF would be a preferred method for concentrating HAdVs and HPyVs from river water followed by subsequent detection and quantification with PCR/qPCR assays.

Recreational Water Quality Index (RWQI) for Colina Lake in Chihuahua, Mexico

Recreational water use provides important benefits for human health; nevertheless, there can be adverse effects if the water is polluted. Aim of this work was to develop a Recreational Water Quality Index (RWQI) for Colina Lake in Mexico. Water samples were collected from March 2011 to February 2012 at seven random locations and at three depths (0.30 m, 1.0 m and 2.0 m). Parameters analyzed were pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), temperature (T), turbidity, total hardness (TH) chlorides (Cl-) and total (TC) and fecal coliforms (FC). Statistical analyses were made considering a 12↔3 factorial arrangement design while the RWQI was calculated for the 0.30 m depth. In general, results for parameters did not differ according to sampling depth or the interaction, but there were statistical differences according to sampling month. The RWQI indicates that water quality is generally adequate for recreational purposes.

From phycocyanin fluorescence to absolute cyanobacteria biomass: An application using in-situ fluorometer probes in the monitoring of potentially harmful cyanobacteria blooms

Cyanobacteria blooms can complicate the economical or recreational use of waters. Many of the bloom forming species are also potential producers of harmful cyanotoxins. The standard method for quantifying phytoplankton biomass, based on inverted microscopy, has high accuracy and is the only one producing biomass results on taxonomic level, but it requires specialized expertise and is time-consuming. Phycocyanin (PC) pigment concentration has been proven as a useful proxy for the concentration of cyanobacteria. Since 2006, we have studied practical solutions of in-situ monitoring of cyanobacteria using PC fluorescence probes. We have studied two eutrophic lakes, Lake Littoistenjärvi and Lake Kuralanjärvi in southwestern Finland using stationary monitoring stations equipped with PC probes. The fluorescence results were compared to independent water samples analyzed using standard methods. The PC fluorescence was positively correlated to cyanobacteria biomass in both lakes. Using site-specific post-calibrations of biomass, PC fluorescence can be used to estimate the absolute biomass of cyanobacteria. The monitoring techniques used in these studies are an applicable and relatively low-cost method to monitor cyanobacteria abundance. With nearly real-time data transfer possibilities, they can be used in management and early warning applications to minimize the harmful effects of cyanobacteria blooms.

Developing an easy-to-apply model for identifying relevant pathogen pathways into surface waters used for recreational purposes.

Swimming in inner-city surface waters is popular in the warm season, but can have negative consequences such as gastro-intestinal, ear and skin infections. The pathogens causing these infections commonly enter surface waters via several point source discharges such as the effluents from wastewater treatment plants and sewer overflows, as well as through diffuse non-point sources such as surface runoff. Nonetheless, the recreational use of surface waters is attractive for residents. In order to save financial and organizational resources, local authorities need to estimate the most relevant pathways of pathogens into surface waters. In particular, when detailed data on a local scale are missing, this is quite difficult to achieve. For this reason, we have developed an easy-to-apply model using the example of Escherichia coli and intestinal enterococci as a first approach to the local situation, where missing data can be replaced by data from literature. The model was developed based on a case study of a river arm monitored in western Germany and will be generalized for future applications. Although the limits of the EU Bathing Water Directive are already fulfilled during dry weather days, we showed that the effluent of wastewater treatment plants and overland flow had the most relevant impact on the microbial surface water quality. On rainy weather days, combined sewer overflows are responsible for the highest microbial pollution loads. The results obtained in this study can help decision makers to focus on reducing the relevant pathogen sources within a catchment area.

Are fecal indicator bacteria appropriate measures of recreational water risks in the tropics: A cohort study of beach goers in Brazil?

Regulating recreational water exposure to pathogens within the tropics is a major public health and economic concern. Although numerous epidemiological studies estimating the risk to recreational marine water exposure have been conducted since the 1950s, few studies have been done in the tropics. Furthermore, many have suggested that the use of fecal indicator bacteria for monitoring recreational water quality in temperate regions is not appropriate in the tropics. We analyzed a large cohort study of five beaches in Sao Paulo, Brazil, conducted during consecutive weekends in the summer of 1999 that estimated risk to water, sand, and food exposures. Enterococci and Escherichia coli concentrations were measured each day of the study. Elevated risks were estimated for both swimming (OR = 1.36 95% CI: 1.05–1.58) and sand contact (OR = 1.29 95% CI 1.05–1.58). A 1 log increase in enterococci concentration was associated with an 11% increase in risk (OR = 1.11 95% CI: 1.04–1.19). For E. coli a 1-log increase in concentration was associated with 19% increase in risk (OR = 1.19 95% CI: 1.14–1.28). Most countries with beaches in the tropics are lower or middle income countries (LMIC) and rely on tourism as a major source of income. We present data that suggests fecal indicator bacteria such as enterococci are an appropriate indicator of risk in tropical urban settings where contamination is coming from predominantly human sources. Additional studies in tropical settings could help inform and refine guidelines for safe use of recreational waters.

THE INFLUENCE OF THE RECREATION ON WATER QUALITY OF THE IVANKOVO RESERVOIR

The basic problems of recreational water use are considered by the case study of Ivankovo reservoir. The influence of different kinds of resting on water quality is found out. Investigation shows that the main impact on ecological conditions of the Ivankovo reservoir is provided by swimming, fishing, motorboat and road transport. Intensive building on the riverside has led to worsening of water quality and considerable degradation of shallows and aquatic complex of the reservoir.

Norovirus Outbreak Associated With a Natural Lake Used for Recreation—Oregon, 2014

Norovirus Outbreak Associated With a Natural Lake Used for Recreation—Oregon, 2014