Sources of pharmaceuticals and personal care products in swimming pools

Advances and research needs for disinfection byproducts control strategies in swimming pools

The control of disinfection byproducts (DBPs) in swimming pools is of great significance due to the non-negligible toxicity and widespread existence of DBPs. However, the management of DBPs remains challenging as the removal and regulation of DBPs is a multifactorial phenomenon in pools. This study summarized recent studies on the removal and regulation of DBPs, and further proposed some research needs. Specifically, the removal of DBPs was divided into the direct removal of the generated DBPs and the indirect removal by inhibiting DBP formation. Inhibiting DBP formation seems to be the more effective and economically practical strategy, which can be achieved mainly by reducing precursors, improving disinfection technology, and optimizing water quality parameters. Alternative disinfection technologies to chlorine disinfection have attracted increasing attention, while their applicability in pools requires further investigation. The regulation of DBPs was discussed in terms of improving the standards on DBPs and their preccursors. The development of online monitoring technology for DBPs is essential for implementing the standard. Overall, this study makes a significant contribution to the control of DBPs in pool water by updating the latest research advances and providing detailed perspectives.

Health-related behaviors and associated factors among swimming pool users in Kombolcha Town, Northeastern Ethiopia

Objective

Unhealthy behaviors during swimming exposes at risk of recreational water-associated diseases. The swimming pool users are the high-risk group for getting and transmitting the diseases. Thus, conducting a study on swimming pool users' health-related behaviors is crucial to prevent the transmission of recreational water-associated diseases.

Methods

This cross-sectional study was employed among 140 randomly selected swimming pool users from April 1st to 30th, 2021 in Kombolcha Town. Data were collected using an interviewer-administered questionnaire and an on-the-spot-observational checklist. The collected data were entered to EpiData version 4.6 and exported to SPSS version 25 for data cleaning and analysis. Determinants of health-related behaviors were identified by using a multivariable logistic regression model at a p-value < 0.05.

Results

The overall good health-related behavior among swimming pool users was 41.4% (95% CI: 33.6-49.3). Out of the total 140 swimming pool users, 55% (95% CI: 46.4-62.9) had good knowledge about health risks during swimming. Good knowledge about health risks during swimming (AOR = 9.64; 95% CI: 3.14-29.61), educational status of college or above (AOR = 6.52; 95% CI: 1.76-24.10) and age being > 28 years (AOR = 6.49; 95% CI: 2.34-18) were factors significantly associated with good health-related behaviors.

Conclusion

The finding of the study showed that the majority of the swimming pool users had poor health-related behaviors. Thus, Kombolcha Town Health Bureau and swimming pool managers should give attention to this population to enhance health-related behaviors through addressing the significant predictors.

Identification of Potential Harmful Transformation Products of Selected Micropollutants in Outdoor and Indoor Swimming Pool Water

This paper presents the estimation of micropollutant decomposition effectiveness and the identification of transformation intermediates formed during selected processes used in the treatment of swimming pool water. Tests were carried out under both indoor and outdoor conditions to simulate the removal of contaminants in different types of pool water basins. Model swimming pool water spiked with caffeine, carbamazepine, bisphenol A and oxadiazon were subjected to chlorination, ozonation, UV radiation, and artificial and sun lightening, carried out as single or combined processes. It was noted that organic micropollutants decompose faster during exposure to natural sunlight than artificial lighting. Caffeine and carbamazepine belong to compounds that are resistant to single ozone or light decomposition. Bisphenol A was completely removed by the action of the chlorination agent NaOCl. The highest compound removal degrees were noted for the integrated action of natural sunlight, NaOCl and O₃. This process allows also for the decomposition of all caffeine and oxadiazon decomposition by-products that potentially are toxic to swimming pool users.

Pathogen performance testing of a natural swimming pool using a cocktail of microbiological surrogates and QMRA-derived management goals

In recent decades, natural swimming pools (NSPs) have gained popularity in Europe, especially in Germany and Austria. NSPs differ from swimming pools in that they utilize biological treatment processes based on wetland processes with no disinfection residual. However, data are missing on the specific log-reduction performance of NSPs to address enteric virus, bacteria, and parasitic protozoa removal considered necessary to meet the North American risk-based benchmark (<35 illnesses per 1,000 swimming events) set by the USEPA for voluntary swimming. In this study, we examined Canada's first NSP at Borden Park, Edmonton, Canada, to address the following three questions: (1) Given normal faecal shedding rates by bathers, what is the total log reduction (TLR) theoretically needed to meet the EPA benchmark? (2) what is the in-situ performance of the NSP based on spiking suitable microbial surrogates (MS2 coliphage, Enterococcus faecalis, and Saccharomyces cerevisiae [Baker's yeast])? and (3) how much time is required to reach acceptable bather risk levels under different representative volume-turnover rates? A reverse-quantitative microbial risk assessment (QMRA) revealed that of the four reference pathogens selected (Norovirus, Campylobacter, Cryptosporidium, and Giardia), only Norovirus was estimated to exceed the risk benchmark at the 50th, 75th, and 95th percentiles, while Campylobacter was the only other reference pathogen to exceed at the 95th percentile. Log-reduction values (LRVs) were similar to previous reports for bacterial indicators, and novel LRVs were estimated for the other two surrogates. A key finding was that more than 24 h treatment time would be necessary to provide acceptable bather protection following heavy bather use (378 bathers/day for main pool and 26 bathers/day for children's pool), due to the mixing dynamics of the treated water diluting out possible residual pool faecal contamination. The theoretical maximum number of people in the pool per day to be below USEPA's 35 gastro cases in 1,000 swimming events was 113, 47, and 8, at the 50th, 75th, and 95th percentiles. Further, the use of ultra-violet disinfection to the pool return flow had little effect on reducing the treatment time required.

The roles of HO•, ClO• and BrO• radicals in caffeine degradation: A theoretical study

ClO^• and BrO^• are newly discovered reactive radicals that contribute to the degradation of micropollutants. However, the research on pollutant degradation by ClO^• and BrO^• is still lacking. Thus, the mechanism, kinetics, and toxicity of caffeine degradation by HO^•, ClO^•, and BrO^• were computationally studied and compared. Results showed that radical adduct formation (RAF) reaction was dominant for HO^•, ClO^•, and BrO^• initiated reactions of caffeine. The main reaction sites were C5 and C8 of caffeine for HO^•, while only the RAF reaction on C8 was prominent for ClO^• and BrO^•. The initiated reaction rate constants of caffeine by HO^•, ClO^•, and BrO^• were in the order of HO^• (5.29 × 10⁹ M^-1 s^-1) > ClO^• (1.40 × 10⁹ M^-1 s^-1) > BrO^• (2.17 × 10⁸ M^-1 s^-1). The kinetic simulation verified that ClO^• played a crucial role in the degradation of caffeine by the UV/chlorine process. In addition to HO-adducts, the subsequent reaction mechanisms of ClO- and BrO-adducts have also been investigated. The formation mechanisms of several important products, namely dimethylparabanic acid (P2), di(N-hydroxymethyl) parabanic acid (P5), 1,3,7-trimethyluric acid (P6), and 8-oxocaffeine (P11), were elucidated. Remarkably, stable chlorinated and brominated intermediates or products were not generated in ClO^•- and BrO^•-mediated subsequent degradations of caffeine. The assessment of aquatic toxicity and health effects showed that caffeine could penetrate the blood-brain barrier (human), and caffeine and its degradation products were potentially harmful to the aquatic environment.

The potential of the organic micropollutants emission from swimming accessories into pool water

The potential leaching of organic micropollutants from swimming accessories was studied in the laboratory experiment. Seventeen different swimming accessories have been placed in various water matrices under different conditions in order to reproduce the actual environmental conditions of swimming pool water. The presence of micropollutants in water samples, after the exposure of swimming accessories, was assessed using indirect indicators (Total Organic Carbon and Phenol Index) and directly using a gas chromatograph coupled with a mass spectrometer with electron ionization. A wide range of organic compounds emitted from swimming accessories have been identified. The most common in tested samples was isophorone. The frequency of its occurrence in 50 swimming pools located in Poland was equal to 89% in concentrations ranged from 0.75 to 1.01 µg L^-1 (below the concentration of 40 µg L^-1, which is estimated to increase the cancer risk). Content of combined chlorine (1.52-3.16 mgCl₂ L^-1) in chlorinated matrices indicated a high potential for disinfection by products (DBPs) formation from organic matter emitted into pool water from swimming accessories. Ten of seventeen tested samples showed the toxic effect, measured as the bioluminescence inhibition of bacteria Aliivibrio fischeri.

Thermal baths as sources of pharmaceutical and illicit drug contamination

Despite the fact that there are tens of thousands of thermal baths in existence, knowledge about the occurrence of pharmaceutically active compounds (PhACs) in untreated thermal wastewater is very limited. Because used thermal water is typically legally discharged into surface waters without any treatment, the effluent poses environmental risks for the receiving water bodies. The aim of this study was to show the occurrence patterns and spatiotemporal characteristics of 111 PhACs in thermal wastewater. Six thermal water outflows of different thermal baths were tested in different seasons in the Budapest metropolitan region (Hungary), and diurnal analysis was performed. After solid-phase extraction, the samples were analysed and quantified by coupling supercritical fluid chromatography and mass spectrometry to perform simultaneous multi-residue drug analysis. The results confirm that water discharge pipes directly transport pharmaceuticals into surface water bodies; 34 PhACs were measured to be over the limit of quantification at least once, and 21 of them were found in more than one water sample. The local anaesthetic drug lidocaine, antiepileptic carbamazepine, analgesic derivative tramadol and illicit drug cocaine were detected in more than half of the samples. Caffeine, metoprolol and bisoprolol (cardiovascular drugs), benzoylecgonine (cocaine metabolite), diclofenac (NSAID), citalopram (antidepressant) and certain types of hormones also have a significant frequency of 30-50%. However, the occurrence and concentrations of PhACs vary according to the season and number/types of visitors. As demonstrated by the diurnal fluctuation, drug contamination of thermal waters can significantly vary, even for similar types of baths; furthermore, the quantity and types of some pollutants rapidly change in the discharged thermal wastewater.

Distribution and Chemical Analysis of Pharmaceuticals and Personal Care Products (PPCPs) in the Environmental Systems: A Review

PPCPs are found almost everywhere in the environment especially at an alarming rate and at very low concentration in the aquatic systems. Many methods-including pressurized hot water extraction (PHWE), pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), and micro-assisted extraction (MAE)-have been employed for their extraction from both surface waters and biota. Solid-phase extraction (SPE) proved to be the best extraction method for these polar, non-volatile, and thermally unstable compounds in water. However, ultrasonic extraction works better for their isolation from sediment because it is cheap and consumes less solvent, even though SPE is preferred as a clean-up method for sediment samples. PPCPs are in groups of-acidic (e.g., diclofenac, ibuprofen, naproxen), neutral (e.g., caffeine, carbamazepine, fluoxetine), and basic pharmaceuticals, as well as antibiotics and estrogens amongst others. PPCPs which are present in trace levels (ng/L) are more often determined by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography-ultraviolent (HPLC-UV). Of these, LC-MS and LC-MS-MS are mostly employed for the analysis of this class of compounds, though not without a draw-back of matrix effect. GC-MS and GC-MS-MS are considered as alternative cost-effective methods that can also give better results after derivatization.

Application of UVOX Redox® for swimming pool water treatment: Microbial inactivation, disinfection byproduct formation and micropollutant removal

Alternative disinfection technologies may overcome some of the limitations of conventional treatment applied in swimming pools: chlorine-resistant pathogens (e.g. Cryptosporidium oocysts and Giardia cysts) and the formation of chlorinated disinfection byproducts. In this paper, results of full scale validation of an alternative disinfection technology UVOX Redox^® (hereinafter referred to as UVOX) that combines ozonation and UV irradiation are presented. The performance was assessed in terms of microbial inactivation, disinfection byproduct formation and micropollutant removal. UVOX was able to achieve 1.4-2.7 log inactivation of Bacillus subtilis spores at water flows between 20 and 76 m³/h. Lower formation of trichloromethane and dichloroacetic acid was observed with UVOX followed by chlorination when compared to chlorination alone. However, due to the use of ozone and the presence of bromide in the pool water, the formation of trihalomethanes and haloacetic acids shifted to more brominated byproducts. Chlorine alone was able to remove the target micropollutants: acetaminophen, atenolol, caffeine, carbamazepine, estrone, estradiol, and venlafaxine (>97% removal) after 24 h, with the exception of ibuprofen (60% removal). The application of UVOX in chlorinated water enhanced the removal of ibuprofen. The application of UVOX could lower the usage of chlorine to the level that provides an adequate residual disinfection effect.

Regulation, formation, exposure, and treatment of disinfection by-products (DBPs) in swimming pool waters: A critical review

The microbial safety of swimming pool waters (SPWs) becomes increasingly important with the popularity of swimming activities. Disinfection aiming at killing microbes in SPWs produces disinfection by-products (DBPs), which has attracted considerable public attentions due to their high frequency of occurrence, considerable concentrations and potent toxicity. We reviewed the latest research progress within the last four decades on the regulation, formation, exposure, and treatment of DBPs in the context of SPWs. This paper specifically discussed DBP regulations in different regions, formation mechanisms related with disinfectants, precursors and other various conditions, human exposure assessment reflected by biomarkers or epidemiological evidence, and the control and treatment of DBPs. Compared to drinking water with natural organic matter as the main organic precursor of DBPs, the additional human inputs (i.e., body fluids and personal care products) to SPWs make the water matrix more complicated and lead to the formation of more types and greater concentrations of DBPs. Dermal absorption and inhalation are two main exposure pathways for trihalomethanes while ingestion for haloacetic acids, reflected by DBP occurrence in human matrices including exhaled air, urine, blood, and plasma. Studies show that membrane filtration, advanced oxidation processes, biodegradation, thermal degradation, chemical reduction, and some hybrid processes are the potential DBP treatment technologies. The removal efficiency, possible mechanisms and future challenges of these DBP treatment methods are summarized in this review, which may facilitate their full-scale applications and provide potential directions for further research extension.

Determination of Micropollutants in Water Samples from Swimming Pool Systems

The present study investigated the occurrence of selected micropollutants, including emerging contaminants from a group of pharmaceuticals and personal care products (PPCPs) in water samples from swimming pool systems. The study area was selected based on the lack of available information regarding suspected contamination of swimming pool water by PPCPs. The variety and concentration of chemical compounds in these aquatic systems can be quite diversified, presenting a challenge in terms of both purification and quality control. Determination of PPCPs requires very sensitive analytical methods that make it possible to confirm the presence of tested compounds in a complex organic extract. In this field, gas chromatography-mass spectrometry (GC-MS) can be used. With this system, selected ion monitoring can be performed, which reduces the detection limits of the investigated analyte. This paper aims to present an analytical method and strategy that can be adapted to obtain information on the composition of water in swimming pool systems. The sample preparation methodology, including Solid Phase Extraction, has been developed for the trace determination of two pharmaceuticals—caffeine, carbamazepine—and one sunscreen constituent—benzophenone-3—in swimming pool water samples.