Recreational Use of Spa Thermal Waters: Criticisms and Perspectives for Innovative Treatments

First report of Acanthamoeba spp. isolation in a recreational hot spring in the Philippines

Natural hot springs are ideal places and environmental matrices that offer relaxation to people and microorganisms of different types. A total of 40 surface water samples were collected from the five identified collection sites, eight water samples for each site. Collection sites are designated 200 m apart to cover the entire study site. Surface water samples were collected approximately 10-20 cm from the surface. Water samples were filtered, cultured, and microscopically observed for 14 days. After 14 days of cultivation, eight (20%) water samples revealed cystic and trophozoite stages. Polymerase chain reaction using JDP1 and JDP2 specific primers confirmed the presence of Acanthamoeba spp. from two of our isolates in the hot spring, isolates 1.1 and 5.1. Further sequencing revealed that the isolates are Acanthamoeba T20 and Acanthamoeba genotype T7. Sequences were deposited to GenBank and were assigned accession numbers PP741726 and PP741727, respectively. The isolation of Acanthamoeba spp. in hot springs has significant health implications, especially for those who use it for recreational activity. Private resort owners are highly encouraged to regularly monitor and maintain hot spring resorts to avoid future infections.

Surface modification of TiO2 nanoparticles with organic molecules and their biological applications

In recent years, titanium(IV) dioxide nanoparticles (TiO₂NPs) have shown promising potential in various biological applications such as antimicrobials, drug delivery, photodynamic therapy, biosensors, and tissue engineering. For employing TiO₂NPs in these fields, their nanosurface must be coated or conjugated with organic and/or inorganic agents. This modification can improve their stability, photochemical properties, biocompatibility, and even surface area for further conjugation with other molecules such as drugs, targeting molecules, polymers, etc. This review describes the organic-based modification of TiO₂NPs and their potential applications in the mentioned biological fields. In the first part of this review, around 75 recent publications (2017-2022) are mentioned on the common TiO₂NP modifiers including organosilanes, polymers, small molecules, and hydrogels, which improve the photochemical features of TiO₂NPs. In the second part of this review, we presented 149 recent papers (2020-2022) about the use of modified TiO₂NPs in biological applications, in which specific bioactive modifiers are introduced in this part with their advantages. In this review, the following information is presented: (1) the common organic modifiers for TiO₂NPs, (2) biologically important modifiers and their benefits, and (3) recent publications on biological studies on the modified TiO₂NPs with their achievements. This review shows the paramount significance of the organic-based modification of TiO₂NPs to enhance their biological effectiveness, paving the way toward the development of advanced TiO₂-based nanomaterials in nanomedicine.

Sulphurous air pollutants and exposure events of workers in thermal-mineral springs: a case study of Contursi Terme (Salerno, Italy)

Thermo-mineral springs are widely spread over the volcanic areas of Salerno, a city in southern Italy. Although the water of thermal structures provides beneficial effects on human health, the air is characterized by the presence of potentially toxic compounds, such as hydrogen sulphide (H₂S) and sulphur dioxide (SO₂). Exposure to sulphurous compounds may have detrimental effects on human health, with asthma being the most common. In this study, air concentrations of H₂S and SO₂ in the thermal springs of Contursi Terme (Salerno, Italy) were monitored for 4 months (using both active and passive sampling), along with the chemical and microclimatic characterization of thermal water, to assess workers' exposure to these pollutants. An in-depth characterization of indoor air at the springs is paramount to establish emission control limits for occupational exposure and to take protective measures. The air concentration of SO₂ varied from 0.11 ± 0.02 to 0.91 ± 0.02 mg/m³, following a seasonal pattern (higher values in winter and lower in spring). Conversely, indoor H₂S concentrations did not vary significantly with time, but outdoor levels (from 0.40 ± 0.03 to 1.90 ± 0.03 mg/m³) were always higher than indoor ones (from 0.11 ± 0.03 to 0.56 ± 0.03 mg/m³). Not negligible air concentrations of these pollutants were detected in this thermal spring workplace, so further investigations are needed to ensure workers' safety.

Effective removal of organics from Bayer liquor through combined sonolysis and ozonation: Kinetics and mechanism

The presence of organic compounds in the waste liquor is of serious environmental concern that has plagued the development of alumina industry (Bayer Process). The present work attempts to develop a green and efficient process for removal of organics utilizing combined effect of sonolysis and ozonation (US/O₃). The effects of reaction duration, ozone concentration and ultrasonic power are assessed for sonolysis (US), ozonation (O₃) and combination of sonolysis and ozonation (US/O₃). The optimal conditions for US/O₃ treatment system is identified to be a reaction duration of 7 h, ozone concentration of 7.65 g/h, and ultrasonic power of 600 W. The total organic carbon (TOC) removal and decolorization are 60.13% and 87.1%, respectively. The process can be scaled-up to industrial scale, which could potentially serve to be a convenient, safe and sustainable alternative to the exisiting treatment technologies. Additionally, the treated waste water can be reused contributing to an improvement in the overall economics.

Microbial pollution in inland recreational freshwaters of Quetta, Pakistan: an initial report

Parasitic contamination of surface waters, especially recreational waters, is a serious problem for under-developed nations like Pakistan, where numerous outbreaks of parasitic diseases are reported each year. In the current study, parasitic presence in two surface waters (Hanna Lake and Wali-Tangi Dam) of Quetta was monitored quarterly for 1 year. The methodology involved the pre-concentration of the water samples and the subsequent preparation for the microscopic search of parasites. Physico-chemical and bacteriological variables were also studied. Wet staining, modified Trichrome staining, and modified acid-fast staining methods were used to identify various parasitic forms (cysts, oocysts, eggs, trophozoites). Collectively 11 parasitic elements (10 in Lake and 8 in Dam) belonging to 10 species were recorded, many of which are potential human pathogens. The species identified include Trichomonas sp., Isospora sp., Balantidium coli, Cryptosporidium sp., Entamoeba spp., amoebas, Microsporidium sp., Endolimax nana, Ascaris lumbricoides, and Giardia spp. Parasitic contamination remained persistent in both locations throughout the year independent of physico-chemical parameters (temperature, EC, pH, turbidity, and DO) and bacterial concentration of water. Reliance on bacterial presence for monitoring of recreational waters can be a risk for tourists. Entamoeba spp. and A. lumbricoides may be used for surface water monitoring in these waters.

Disinfection of Therapeutic Spa Waters: Applicability of Sodium Hypochlorite and Hydrogen Peroxide-Based Disinfectants

The microbial water quality of therapeutic pools operating without disinfection is recurrently compromised, posing a risk to bathers’ health. The complex composition of such waters and the sensitivity of their therapeutic components hinder the use of traditional chlorine-based disinfectants. The present study aimed to investigate the applicability of a hydrogen peroxide-based disinfectant in therapeutic water in comparison with hypochlorite. Disinfection efficacy, byproduct formation, and the fate of therapeutic components were tested for both disinfectants under laboratory conditions, applying different doses and contact times. Disinfection efficacy was found to be matrix-dependent, especially that of hydrogen peroxide against Pseudomonas aeruginosa (a 10- to 1000-fold difference). Hypochlorite treatment presented a significant chemical risk through the generation of byproducts, mainly brominated and iodinated compounds and combined chlorine. Of the alleged therapeutic components, sulfide ions were eliminated (≥86% loss) by both disinfectants, and hypochlorite reacted with iodide ions as well (≥70% removal). Based on their composition, only 2% of Hungarian therapeutic waters can be treated by chlorination due to high concentrations of ammonia and/or organic compounds. Hydrogen peroxide is applicable to 82% of the waters, as the presence of sulfide ions is the only limiting factor. Due to the matrix effect, close control of residual disinfectant concentration is necessary to ensure microbial safety.

Disinfection of therapeutic water - balancing risks against benefits: case study of Hungarian therapeutic baths on the effects of technological steps and disinfection on therapeutic waters

Thermal therapeutic pools in most countries are operated in a manner similar to swimming pools: with water circulation, filtration and disinfection. However, in some countries, including Hungary, therapeutic pools are traditionally not treated this way, in order to preserve the therapeutic qualities of the water. However, dilution and frequent water replacement applied in these pools are often insufficient to ensure adequate microbial water quality, posing a risk of infection to the bathers. In the present case study, the impact of water treatment (including chemical disinfection by hypochlorite or hydrogen peroxide) was investigated on the therapeutic components of the water in seven Hungarian spas of various water composition. Microbial quality was improved by both disinfectants, but hypochlorite reduced the concentration of the therapeutic components sulfide, bromide, and iodide ions by 40-99%, and high levels of disinfection by-products were observed. Hydrogen peroxide only affected sulfide ion (91% reduction). Other technological steps (e.g., transport or cooling by dilution) were found to have significant impact on composition, often outweighing the effect of disinfection. The current case study demonstrated that thermal waters may be treated and disinfected with minimal loss of the therapeutic compounds, if an adequate treatment procedure is selected based on the water composition.

COVID-19: Research Directions for Non-Clinical Aerosol-Generating Facilities in the Built Environment

Physical contact and respiratory droplet transmission have been widely regarded as the main routes of COVID-19 infection. However, mounting evidence has unveiled the risk of aerosol transmission of the virus. Whereas caution has been taken to avoid this risk in association with clinical facilities, facilities such as spa pools and Jacuzzis, which are characterized by bubble-aerosol generation, high bather loads, and limited turnover rates, may promote aerosol transmission. Focusing on these non-clinical facilities in the built environment, a review study was undertaken. First, the typical water disinfection and ventilation-aided operations for the facilities were illustrated. Second, cross comparisons were made between the applicable standards and guidelines of the World Health Organization and countries including Australia, Canada, China, the United Kingdom, and the United States. The similarities and differences in their water quality specifications, ventilation requirements, and air quality enhancement measures were identified; there were no specific regulations for preventing aerosol transmission at those aerosol-generating facilities. Third, a qualitative review of research publications revealed the emergence of studies on potential air-borne transmission of COVID-19, but research on built facilities posing high risks of aerosol transmission remains scant. This study’s results inform key directions for future research on abating aerosol transmission of COVID-19: the development of bespoke personal protective equipment and engineering and management controls on water quality, ventilation, and air quality.

Challenges of Spa Tourism in Andalusia: Experts' Proposed Solutions

Water is the common thread and attraction factor of the tourism facilities called "spas", which are part of health and beauty services. Spa use is currently experiencing a boom that reflects changes in populations, such as an increase in economic wellbeing and a desire to reunite with nature. This research's objectives were to understand spa tourism's structural and operational dimensions and to assess this sector's current situation by using the Delphi method with a panel of 22 experts. The results show that these experts believe that, in Andalusia, spas energize the area as a tourism destination through their natural resources and conservation of key elements. However, spa development policies are scarce, including a lack of autonomous community laws regarding these facilities.

Exploring the Bacterial Communities of the Kaiafas Thermal Spring Anigrides Nymphes in Greece Prior to Rehabilitation Actions

Anigrides Nymphes of Lake Kaiafas is a thermal spring that is well known for its therapeutical properties, as the hot water (32-34 °C) is rich in sulfur compounds and minerals. Nowadays, efforts are made from the Hellenic Republic to modernize the existing facilities and infrastructure networks of the area. To study the complex ecosystem of the thermal spring, we collected water from four sampling points (Lake, and Caves 1, 2, and 3). Filtration method was used for microbial enumeration. In parallel, total bacterial DNA was extracted and subjected to next-generation sequencing (NGS). A total of 166 different bacterial families were detected. Differences in families, genera, and species abundances were detected between the different sampling points. Specifically, Comamonadaceae was the most common family detected in Lake and Cave 3. Similarly, in Caves 1 and 2, Rhodobacteraceae was detected at a higher percentage compared to the rest of the families. Moreover, the detection of sequences assigned to waterborne or opportunistic pathogens, i.e., Enterobacteriaceae, Legionellaceae, Coxiellaceae, and Clostridiaceae, as well as Enterococcus and Vibrio, is of great importance. Although the presence of pathogens was not examined by quantitative PCR, the detection of their sequences strengthens the need of the planned rehabilitation actions of this natural environment in order to allow human swimming.

The Role of Thermal Water in Chronic Skin Diseases Management: A Review of the Literature

The benefits of thermal water in different diseases have been known since ancient times. Over the past decades, a re-assessment of the use of mineral water for the treatment of several pathologic conditions has taken place around the world. Today, water therapy is being practiced in many countries that have a variety of mineral springs considerably different in their hydrogeologic origin, temperature, and chemical composition. Thermal water and balneotherapy offer several advantages: this approach needs no chemicals or potentially harmful drugs; there are almost no side effects during and after treatment, and there is a low risk to the patient’s general health and well-being. However, it is difficult to evaluate the efficacy of this therapeutic approach in clinical practice due to the complexity of molecular mechanisms underlying its efficacy. Here we review the current knowledge of the chemical, immunological, and microbiological basis for therapeutic effects of thermal water with a specific focus on chronic inflammatory skin diseases. We also describe recent evidence of the major dermatologic diseases that are frequently treated by balneotherapy with a remarkable rate of success. Moreover, we discuss the potential role of balneotherapy either alone or as a complement to conventional medical treatments.

Protocols and self-checking plans for the safety of post-COVID-19 balneotherapy

During the COVID-19 pandemics, balneotherapic establishments were closed in Italy like in the rest of Europe. The Italian Foundation for Research in balneotherapy (FoRST) was asked to prepare a safety protocol to be proposed to the National Health Authorities to allow the establishments to restart their activity when possible, under safe conditions (the so-called Phase-2). The group of experts proposed the following hygienic and sanitary protocols of risk management for the initial reopening of the balneology settings in Italy. The plan aims to define the operating procedures to be implemented at the balneology establishments for the beginning of Phase-2 and to keep them constantly updated in the different periods that will characterize Phase-2 in relation to the trends of the disease. To this end the procedures, defined on the basis of the scientific state-of-the-art available today, will be updated and revised from time to time whenever further scientific evidence and directives from the Health Authorities make it necessary and/or useful.

A Qualitative Study of Patients' Beliefs and Perception on Medicinal Properties of Natural Hot Spring Bath for Musculoskeletal Problems

Natural therapy modalities such as thermal therapy and balneotherapy are commonly being practiced for the management of chronic aches and pain all over the world. Nepal has many such natural hot water springs among which few are famous for therapeutic purposes. Thousands of people with some musculoskeletal problem visit those places in the hope of getting rid of their problems. This study aimed to understand their belief in such therapies, expectations, and satisfaction after treatment along with their knowledge of the safety of hot spring water bath. Among 126 participants interviewed, 31% had inflammatory arthritis, followed by degenerative disorders in 29.4% and soft-tissue rheumatism in 12.7%. Around three-quarters believed that hot spring water has natural healing power and thus can improve their pain. Many even believed that water in natural springs is devoid of any chemicals. So, it is a safe treatment option. Regarding the expectation of cure, they had mixed opinions. Naïve participants hoped they might find a permanent cure in thermal baths. However, repeated visitors said that the effect usually lasted for a few months and they have to visit there regularly. Almost two-thirds of people thought that such natural treatment does not have any side effects. Few stated that they had faced certain problems after the treatment. The water tested from the study site showed that it contained a higher amount of chlorine and sulfate in comparison to other hot water springs in Nepal. The minerals present in water might be a cause of temporary relief of pain. Also, outbreaks of infection from common spring baths have to be considered as such cases have been reported in the past. In conclusion, the medicinal benefits of such natural hot water springs have to be studied further and awareness regarding safety should be given to the people seeking treatment.

Analysis of the Microbiome (Bathing Biome) in Geothermal Waters from an Australian Balneotherapy Centre

Balneotherapy is an ancient practice which remains commonplace throughout the world due to perceived health benefits that include relief of arthritis, fibromyalgia and relaxation. However, bathing environments are not sterile and natural spring waters may harbour natural microbial populations that include potential pathogens. We elucidated the microbial community from water taken from the borehole, pre-filter water (chlorinated, cold and post-bathing water) and post-filter water at a commercial Australian natural hot spring bathing facility. Thiobacillus, Sphingobium and Agrobacterium were the predominant genera in samples collected from the borehole. The predominant genera changed to Sphingobium, Parvibaculum and Achromobacter following chloride treatment and Azospira replaced the Achromobacter once the water reached ambient temperature and was stored ready to be used by bathers. The microbial community changed again following use by bathers, dominated by Pseudomonas, although Sphingobium persisted. No total or faecal coliforms were observed in any of the samples except for the post-bathing water; even there, their presence was at very low concentration (2.3 cfu/mL). These results confirm the lack of pathogens present in these hot spring waters but also suggests that good management of post-bathing water is required especially if the water is used for borehole water recharge.

The microbiota as a candidate biomarker for SPA pools and SPA thermal spring stability after seismic events

Worldwide, the location of thermal springs overlaps seismic areas, and the higher occurrence of earthquakes may impact on water stability and safety. The hydrogeological perturbations pose environmental and public health risks that can be monitored by well-established chemical, physical and biological parameters. Specific health concerns involve the exposure of the population to the medical or wellness uses of SPA thermal waters, e.g. in respiratory or hydropinic treatments as well as during rehabilitative or recreational activities in pools. Since SPA waters are characterized by their own microbiota, we analysed by 16S amplicon sequencing the dynamics of water microbial communities after the August 2017 Ischia island earthquake. For the first time, we report the impact of a seismic event on a thermal spring water, whose microbiota was deeply characterized before and immediately after the natural disaster. The biodiversity stability of the water underwent a dramatic disturbance following the earthquake, as summarized by a Shannon index moving from 1.300 during May 2016-July 2017, up to 1.600 during the first 20-70 h after the event and slightly slowing down to 1.500 after 30 days and to 1.400 after 6 months. Microbiota analysis showed a sudden reduction of the relative abundance of autochthone thermophilic species within the first 20 h and a parallel increase of other thermophilic species as well as of ectopic bacteria from soil, sediments, sea, freshwater and wastewaters. Cultivable mesophilic bacteria were observed only in the first 20 h sample (7 × 10³/L), even if the presence of faecal contamination traces was detected by Real Time PCR also up to 70 h after the disaster. OTUs analysis of putative metabolic functions showed several changes between pre and post event, such as in the distribution of Sulphur metabolizing and Carbon fixation species. The restoration of the original pattern followed a slow trend, requiring over six months. The observed results confirm the impact of the earthquake on the microbiota structure of the underground thermal spring water, suggesting further perspectives for monitoring water stability and safety issues by a metagenomic approach.

Untouchability of natural spa waters: Perspectives for treatments within a personalized water safety plan

Natural SPA waters and their environments were known since ancient times and used for health or recreational purposes in different societies, worldwide. The composition and uses of these spring waters may not allow standard disinfection in pools, representing a challenge for hygiene management. Several safety and quality procedures were proposed, but a systematic approach is still needed. Here, we focus on alternative strategies to provide hints for developing a sustainable Water Safety Plan, based on intrinsic water properties and photocatalytic materials. The antimicrobial activity of four different SPA waters with high mineral content and one drinkable spring water with a low mineral content, was assessed and then tested for the additional bactericidal activity of Titanium Dioxide (TiO₂) nanomaterials and/or light exposure at different wavelengths (200-635 nm). A native antibacterial activity was observed in all high mineral content waters, with a CFU reduction of 75-80%. The bactericidal action of TiO₂ showed an additional incremental effect, with a reduction of over 99% within 2-5 h. Interestingly, the antibacterial photocatalytic effect was detected also in the visible light range, with a possible pick around 450-455 nm, blue-light. Based on observed results, we propose a model for developing a water safety plan, considering water properties and bather exposure. This candidate approach is personalized on water composition and pool use, trying to avoid chemical disinfectants. Photocatalytic nanotechnologies represent one of the promising alternative treatments and can provide novel perspectives for a sustainable managing of natural SPA water hygiene.

To treat or not to treat? Misbeliefs in spa water disinfection

"Spa waters should be left untreated" says the dogmatic approach. Health authorities of European countries having traditional spa culture strictly control hygienic conditions of bathing in thermal/mineral waters. These regulations are based on the assumption that chemical treatment (disinfection) of such waters impacts their healing effects. However, a slow change of paradigm has been observed in studying the mode of action of spa waters that could help overcome recent attitudes. Organic content or the role of microbiome has also been emphasized by some authors recently. The article deals with possible interactions among aquatic microorganisms and the disinfection and health effects of spa waters and tries to explain the new findings in this field.

Proposal of Value for Customer of Spas: Expectations of Spa Patients and Tourist in Polish Spas

Literature on the trends of health tourism development has proven that it is becoming one of the most important tourism activities. With the growing popularity of this form of tourism, the structure of the needs of tourists and spa patients is simultaneously changing. This article presents the results of self-research carried out in Polish spa resorts based on a sample of 753 patients and spa tourists. The purpose of the research carried out was the development of a value proposition for the client of a spa enterprise as an element of a business model. At the same time, this paper points to the need to base spa activity on the values of sustainable development through key spa resources in the form of a therapeutic climate and natural raw materials applied in spa therapy. The key values for patients and spa tourists are the improvement of health with natural therapeutic resources, recreation in a place with a healing climate, achieving the effect of the treatment, the development of cultural activities, the possibility of taking care of a child during treatment, and the introduction of a psychologist and leisure animator. The mentioned features may become the basis for building a business model of spa enterprises to adapt the value propositions of a client in their business models to the needs demonstrated by the beneficiaries of these values. The problem raised in the article requires a simultaneous consideration of the principles of sustainable development in relation to the natural resources used in spa therapy.