Recreational Water Environments Research Articles

The challenge of dry-weather sewage intakes as a sustainable strategy to develop urban sanitation in the tropics

Abstract Informal housing, and operational and management deficiencies, influence sewerage system performance in Brazil. Inadequate sewage volumes in storm sewers lead to fecal contamination and affect recreational water environments. As overflow structures, dry-weather sewage intakes (DWSIs) are used to intercept and transfer sewage from storm- to sewage- sewers. For cities without public services, the DWSI strategy has been suggested as an option to enable easier and more rapid responses in terms of sewage pollution control. The strategy may also lead to gradual construction of a separate sewerage system in a two-step plan: initially, based on the construction of DWSIs and wastewater treatment plants, and then, on the construction of separate sewers. The paper is a discussion of the main technical challenges in sustainability of the DWSI strategy, and includes a case study of slum and other informal housing areas in Rio de Janeiro.

'Don't put your head under water': enteric viruses in Brazilian recreational waters.

Like in many other countries, virologic analyses are not routinely performed in Brazil in monitoring water quality for recreational purposes. We surveyed current research regarding viral contamination of recreational water environments in Brazil. Among the enteric viruses studied in Brazilian recreational waters, we highlight adenoviruses, rotaviruses, enteroviruses and noroviruses. Although there has been relatively little research on outbreaks related to bathing in recreational water environments in Brazil, noroviruses and adenoviruses are the viruses that are most often related to outbreaks. Better surveillance of the occurrence of enteric viruses in water could improve the assessment of risk to human health as well as indicate the sources of contamination and thus demonstrate the importance of adequate environmental sanitation.

Bacteriological quality of swimming pool and spa water in northern Greece during 2011–2016: is it time for Pseudomonas aeruginosa to be included in Greek regulation?

AbstractThe risk of illness or infection associated with recreational water environments is mainly associated with faecal water contamination. Non-faecal human shedding into the pool water or surrounding area is also a potential source of pathogens such as Pseudomonas aeruginosa. The aim of the current study is to describe and evaluate the bacteriological quality of 2,844 swimming pool and jacuzzi/spa water samples in northern Greece during the 2011–2016 period. Bacteriological quality of recreational water includes heterotrophic bacteria, total coliforms and Escherichia coli according to Greek Hygienic Regulation. P. aeruginosa is a significant agent of opportunistic infection in aquatic environments and was also examined in the aforementioned samples. We aimed to indicate the importance of including P. aeruginosa as a recreational water quality indicator in the revised Hygienic Regulation. Data analysis was performed using SPSS 22.0. The quality of all types of swimming pools was evaluated as excellent since less than 5% was found not to meet the regulations. Considering the presence and concentration of P. aeruginosa, the number of samples that would not meet the standards would differ significantly (18.9%). P. aeruginosa was detected in a larger amount of samples (15.2%) than E. coli (0.6%), which indicates that P. aeruginosa should be assessed as an important factor.

Applying QMRA and DALY to assess health risks from river bathing

To estimate the health impact of bathing in urban river waters a two-step risk assessment was conducted using the example of the Ruhr River in North-Rhine Westphalia (Germany). The risk of acquiring gastrointestinal illness (GI) due to bathing in the Ruhr River was the focus of this analysis. Referring to the WHO guidelines for safe recreational water environments, risk was defined as the probability of occurrence x severity of harm. Thus, the probability of acquiring GI by bathing in the Ruhr River has been calculated by means of the quantitative microbial risk assessment (QMRA) method. Additionally to this, harm was operationalized by using the DALY metric, quantifying the impact of disability for public health. The calculation of the DALYs based on the QMRA results, disease and lethality data of the population, duration of diseases, disability weights and a demographic profile of a regionally determined potential bathing population. DALYs were calculated for norovirus gastroenteritis, rotavirus gastroenteritis, cryptosporidiosis and giardiasis. The calculated DALYs were set into relation to other risks of daily life. Furthermore the effect of age weighting and time discounting for this site-specific population was considered. The viral load caused the main part of the environmental burden of disease by bathing in the river. The calculated DALYs are significantly lower than DALYs for all cause GI in Germany, which reach 1.19 DALY/1000, or DALYs accepted for an official EG designated bathing water (2.579 DALYs/1000 persons) but on a comparable level with the DALY for drowning (0.26 DALY/1000 Persons). The DALY concept provides a complementary tool to the QMRA for evaluating and comparing health risks arising from a specific environment for a specific population and behaviour and for comparing with other health risks of daily life.

What about behaviours in swimming pools? Results of an Italian multicentre study

The behaviour of swimming pool users plays an important role in the prevention of chemical, microbial and physical risks associated with these recreational water environments. The aim of this study was to evaluate the hygiene-related behaviours and knowledge of users of indoor swimming pools in five Italian cities. A cross-sectional study was carried out using an anonymous self-administered questionnaire. The association between specific variables and patterns of behaviours and knowledge was assessed. A total of 4315 questionnaires were analysed. Of all respondents, 41.7% declared they had never read the swimming pool rules; 70.9% take a shower before entering the swimming pool; 13.5% said they urinated at least once in a swimming pool; 93.9% always wear proper footwear; 92.1% know what warts are and 69.3% know what mycosis is. A significant association was found between not reading the pool rules and unsafe behaviours, such as not showering (OR: 1.44, 95% CI 1.25–1.65), urinating in the pool (OR: 1.70, 95% CI 1.41–2.03) and not wearing any footwear (OR: 1.24, 95% CI 0.96–1.62). Male gender was significantly associated with urinating in the swimming pool (OR: 1.45, 95% CI 1.21–1.74) and not wearing footwear (OR: 1.71, 95% CI 1.32–2.23), but it showed to be protective against not showering (OR: 0.78, 95% CI 0.68–0.89). An age ≤18years was a risk factor for not reading the pool rules (OR: 2.32, 95% CI 2.05–2.63), not wearing footwear (OR: 2.16, 95% CI 1.67–2.82) and not knowing what mycosis (OR: 7.04, 95% CI 5.34–9.27) and warts (OR: 7.94, 95% CI 6.86–9.20) are. Results reveal that incorrect behaviours are widespread among swimming pool users and that there is little awareness of the importance of reading pool rules for reducing health risks.

Water Quality: Guidelines, Standards and Health: Assessment of Risk and Risk Management for Water-Related Infectious Disease

The quality of water, whether it is used for drinking, irrigation or recreational purposes, is significant for health in both developing and developed countries worldwide. In responding to this challenge, countries develop standards intended to protect public health. Recognising this, the World Health Organization (WHO) develops ‘guidelines’ that present an authoritative assessment of the health risks associated with hazards through water and of the effectiveness of approaches to their control. To date, the various WHO guidelines concerned with water ( Guidelines for drinking-water quality; Guidelines for the safe use of wastewater and excreta in agriculture and aquaculture; Guidelines for safe recreational water environments ) have been developed in isolation from one another. However, their common primary concern is for health hazards derived from excreta. Addressing their specific areas of concern together will tend to support better health protection and highlight the value of interventions closer to sources of pollution, which may otherwise be under-valued. The potential to increase consistency in approaches to assessment and management of water-related microbial hazards was discussed by an international group of experts between 1999 and 2001. These discussions led to the development of a harmonised framework, which was intended to inform the process of development of guidelines and standards. Subsequently, a series of reviews was developed and refined, which addressed the principle issues of concern linking water and health to the establishment and implementation of effective, affordable and efficient guidelines and standards. The book is based on these reviews and the harmonised framework. This book will prove invaluable to all those concerned with issues relating to microbial water quality and health, including environmental and public health scientists, water scientists, policy makers and those responsible for developing standards and regulations. This title belongs to WHO Water Series . ISBN: 9781780405889 (eBook) ISBN: 9781900222280 (Print)

Knowledge, risk perception and behaviours in swimming pool users of Palermo city, Sicily

To assess knowledge, risk perception and behaviours of a sample of swimming pool users in Palermo. A total of 498 subjects were interviewed by self-administered anonymous questionnaire including socio-demographic questions, knowledge/risk perception and behaviours. Overall, 289 subjects (58%) had a mean of 1.9±1.2 healthy behaviours. Age older than 30 years (OR=0.46; 95% CI=0.26–0.81), female sex (OR=0.52; 95% CI=0.35–0.76) and a high knowledge score (OR=0.15; 95% CI=0.03–0.69) were significantly associated with having healthy behaviours in both univariate and multivariate analysis. Unhealthy behaviours can be frequently found in swimming pool bathers and, particularly, in some target groups. Public health prevention strategies should be implemented to improve public awareness and information on a safe use of recreational water environments.

Molecular identification of Hartmannella vermiformis and Vannella persistens from man-made recreational water environments, Tehran, Iran

A survey was conducted on man-made recreational water located in different regions of Tehran, Iran to detect the free-living amoebae present in ponds and fountains of parks and squares. Fifty water samples from 22 municipal districts of Tehran were screened for free-living amoebae and identified by morphological characters and polymerase chain reaction amplification. Amoebae detected were identified as Hartmannella vermiformis (12 %) and Vannella persistens (4 %), which are the first reports of these two amoebas in recreational water environments of Iran. Since, H. vermiformis, which is highly similar to strains serving as hosts for Legionella pneumophila, is a common component of the microbial community in fresh surface water. Although Vannella spp. is not proved to be pathogenic itself, they are capable of harboring pathogenic intracellular organisms. Due to some reports related to pathogenicity of these amoebas, the particular hazard related to these microorganisms should be taken into account in the encounter with drinking and washing in these waters. We recommend control strategies based on physical removal rather than on disinfection to be adopted where necessary.

Derivation of numerical values for the World Health Organization guidelines for recreational waters

In April 2001, draft ‘Guidelines’ for safe recreational water environments were developed at a World Health Organization (WHO) expert consultation. Later the same month, these were presented and discussed at the ‘Green Week’ in Brussels alongside the on-going revision of the European Union Bathing Water Directive 76/160/EEC. The WHO Guidelines cover general aspects of recreational water management as well as define water quality criteria for various hazards. For faecal pollution, these include faecal indicator organism concentrations and an assessment of vulnerability to faecal contamination. Central to the approach set out in the WHO Guidelines are: (i) the concept of beach profiling to produce a ‘sanitary inspection category’ which implies a priori hazard assessment as a core management tool and (ii) the prediction of poor water quality to assist in real time risk assessment and public health protection. These management approaches reflect a harmonized approach towards the assessment and management of risk for water-related infectious disease being applied by WHO. Numerical microbiological criteria for intestinal enterococci are proposed in the new Guidelines. These were developed using a novel approach to disease burden assessment, which has been applied to both recreational waters and urban air quality. This paper explains the scientific rationale and mathematical basis of the new approach, which is not presented in the WHO Guidelines for recreational waters.

Setting microbiological water quality standards for sea bathing - a critical evaluation

The World Health Organization (WHO) recently produced draft guidelines for safe recreational water environments. The microbiological standards proposed in the guidelines are expected to overestimate the degree of water quality required to provide given levels of public health protection. The WHO standards were obtained by means of a risk assessment which featured a dose-response model derived from a series of randomised controlled trials. The trials have many strengths but biases and problems with statistical analysis are likely to have led to over-estimation of the risks from bathing in the dose-response model. In addition, the WHO risk assessment failed to consider the effects of uncertainty and variability in risk estimates and sensitivity to model assumptions. Improved standards could be obtained by extending the risk assessment to examine these effects and by incorporating a suitably revised dose-response model.