Occurrence of Disinfection By-Products in Swimming Pools in the Area of Thessaloniki, Northern Greece. Assessment of Multi-Pathway Exposure and Risk

This study investigated the occurrence of disinfection by-products (DBPs) (trihalomethanes (THMs), haloacetic acids (HAAs), halonitriles (HANs), halonitromethane (TCNM) and haloketones (HKs)) in different type of swimming pools in the area of Thessaloniki, northern Greece by employing the EPA methods 551.1 and 552.3. Moreover, general water quality parameters (pH, residual chlorine, dissolved organic carbon, UV254 absorption, total nitrogen, alkalinity and conductivity) were also measured. The concentrations of DBPs showed great variability among swimming pools as well as within the same pool between sampling campaigns. HAAs exhibited the highest concentrations followed by THMs, HANs, TCNM and HKs. Exposure doses for four age groups (3–<6 y, 6–<11 y, 11–<16 y and adults) were calculated. Route-specific exposures varied among DBPs groups. Inhalation was the dominant exposure route to THMs and TCNM (up to 92–95%). Ingestion and dermal absorption were the main exposure routes to HAAs (40–82% and 18–59%, respectively), depending on the age of swimmers. HANs contributed up to 75% to the calculated cytotoxicity of pool water. Hazard indices for different exposure routes were <1, suggesting non-carcinogenic risk. Inhalation posed the higher carcinogenic risk for THMs, whereas risk via oral and dermal routes was low. Ingestion and dermal contact posed the higher risk for HAAs. Risk management strategies that minimise DBPs exposure without compromising disinfection efficiency in swimming pools are necessary.

Exposure of cleaning workers to chemical agents and physical conditions in swimming pools and spas

Swimming pools and spas require a high hygiene level, and therefore constant cleaning. In this study, cleaning workers’ exposure to volatile organic compounds (VOCs), trichloramine (TCA), and particulate matter (PM) in the swimming pools and spas were evaluated. Also, statistical methods were employed to determine what activities affect the exposure to disinfection byproducts (DBPs). The study was conducted in 32 swimming pools and spas. The measurement locations were pool areas, bathrooms, and locker rooms, both during cleaning and opening hours. During the cleaning, the total volatile organic compound (TVOC) concentrations were low, on average 96, 251, and 91 µg/m3 for locker rooms, bathrooms, and pool areas, respectively. Similarly, during the opening hours, the TVOC concentrations were on average 78, 125, and 83 µg/m3, for locker rooms, bathrooms, and pool areas, respectively. This is in line with previous studies investigating cleaning work in other environments. The most prevalent compounds during the cleaning were 2-(2-butoxyethoxy)ethanol (DEGBE), 2-(2-ethoxyethoxy)ethanol (DEGEE), 2-butyl-1-octanol, trichloromethane (chloroform), decamethylcyclopentasiloxane (D5), and carbon tetrachloride. The most prevalent compounds during the opening hours were D5, D-limonene, carbon tetrachloride (bathrooms and pool areas), and trichloromethane (bathrooms and pool areas). The TCA concentrations during the cleaning in the bathrooms and pool areas were on average 60 and 67 µg/m3, respectively, and during the opening hours, 28 and 122 µg/m3, respectively. The use of disinfectants was found to increase the TCA concentration in the bathrooms, while the other cleaning products did not. Even though the TCA concentrations were below the WHO’s guideline and the Finnish occupational exposure limit value of 500 µg/m3, the measured TCA levels were occasionally high enough to pose a risk of irritative symptoms. The PM concentrations were low, both in the real-time monitoring (aerodynamic diameter, Dae ≤ 15 µm) and inhalable dust samples (Dae ≤ 100 µm). Highest measured inhalable dust concentration was 350 µg/m3, well below the Finnish occupational limit value of 5,000 µg/m3 for organic inhalable dust.

Water tank and swimming pool detection based on remote sensing and deep learning: Relationship with socioeconomic level and applications in dengue control

Studies have shown that areas with lower socioeconomic standings are often more vulnerable to dengue and similar deadly diseases that can be spread through mosquitoes. This study aims to detect water tanks installed on rooftops and swimming pools in digital images to identify and classify areas based on the socioeconomic index, in order to assist public health programs in the control of diseases linked to the Aedes aegypti mosquito. This study covers four regions of Campinas, São Paulo, characterized by different socioeconomic contexts. With mosaics of images obtained by a 12.1 MP Canon PowerShot S100 (5.2 mm focal length) carried by unmanned aerial vehicles, we developed deep learning algorithms in the scope of computer vision for the detection of water tanks and swimming pools. An object detection model, which was initially created for areas of Belo Horizonte, Minas Gerais, was enhanced using the transfer learning technique, and allowed us to detect objects in Campinas with fewer samples and more efficiency. With the detection of objects in digital images, the proportions of objects per square kilometer for each region studied were estimated by adopting a Chi-square distribution model. Thus, we found that regions with low socioeconomic status had more exposed water tanks, while regions with high socioeconomic levels had more exposed pools. Using deep learning approaches, we created a useful tool for Ae. aegypti control programs to utilize and direct disease prevention efforts. Therefore, we concluded that it is possible to detect objects directly related to the socioeconomic level of a given region from digital images, which encourages the practicality of this approach for studies aimed towards public health.

“I Live Here”: How Residents of Color Experience Racialized Surveillance and Diversity Ideology in a Liberal Predominantly White Neighborhood

In many liberal predominantly white neighborhoods, white residents view their communities as inclusive yet they also engage in racialized surveillance to monitor individuals they perceive as outsiders. Some of these efforts center on people of color in neighborhood open spaces. We use a diversity ideology framework to analyze this contradiction, paying particular attention to how residents of color experience racialized surveillance of their neighborhood’s publicly accessible parks and swimming pools. This article draws on data from neighborhood documents, neighborhood digital platforms, and interviews with residents of a liberal, affluent, predominantly white community that was expressly designed with public spaces open to non-residents. We find that resident surveillance of neighborhood public spaces is racialized, occurs regularly, and happens in person and on neighborhood online platforms where diversity as liability rhetoric is conveyed using colorblind discourse. These monitoring efforts, which are at times supported by formal measures, impact residents of color to varying degrees. We expand on diversity ideology by identifying digital and in-person racialized surveillance as a key mechanism by which white residents attempt to enforce racialized boundaries and protect whiteness in multiracial spaces and by highlighting how Black and Latinx residents, in particular, navigate these practices.

Case Study of Selected Nature Swimming Pools in the South Moravian Region

Nature swimming pools are a sought-after alternative to conventional swimming pools. Their natural water purification system, without the need for chemicals, is beneficial to health and environmentally friendly. Designing such a nature swimming pool is a complex matter because it requires coordination of a number of effects, which can easily cause an imbalance in the entire system. This work uses the case study method to analyse the overall condition of three nature swimming pools in the South Moravian Region during the second half of the swimming pool operation season.

The Occurrence of Unfavorable Phenomena in Swimming Pool Water

The study assessed unfavorable phenomena occurring in swimming pool water, including the occurrence of organic micropollutants in swimming pools and the transformation of these compounds during the swimming pool water treatment processes. The presence of three selected compounds was examined from the personal care products group (PCP) in pool water samples, collected in 2018 and 2019, from fifteen pools characterized using three different solutions of swimming pool water treatment systems. In addition, experimental studies on the effects of UV radiation and ozone on selected organic micropollutants, previously identified in swimming pools and the relationship between swimming pool water turbidity and the concentration of the selected PCP micropollutants, were carried out

Swimming Pool-Related Outbreak of a Rare gp60 Subtype of Cryptosporidium hominis, England, October 2016

In October 2016, Public Health England was initially notified of four cases of cryptosporidiosis among users of two swimming pools. We investigated to identify further cases, the outbreak source, and ensure the implementation of appropriate control measures. Probable primary cases had diarrhoea and reported swimming in the pools 1–12 days prior to illness; confirmed cases were verified by the reference laboratory. Secondary cases had contact with primary cases 1–12 days prior to illness. We identified twenty-two cases: eleven were primary (eight confirmed) and eleven were secondary (five confirmed). Four cases were infected with C. parvum (different gp60 subtypes); all were primary and swam at two pools. Seven primary and secondary cases were infected with C. hominis gp60 subtype IdA16, and all were associated one pool. Failings in pool water treatment and management were identified that likely contributed to the load on the filters and their efficiency. Our investigation identified a complex outbreak, with secondary transmission, involving exposures to two swimming pools. C. hominis IdA16 is rare; it has been isolated from only three previous UK cases. We hypothesize that C. hominis cases arose from a common exposure, and the C. parvum cases were likely sporadic. This investigation highlights the value of integrating epidemiology and microbiology to investigate clusters of Cryptosporidium cases, defining the extent of the outbreak and the likely transmission pathways.