Variations in bacterial community structures during geothermal water recharge-induced bioclogging.

Characterizing bacterial communities is of great significance for targeted control of bacteria-induced clogging during geothermal water recharge. Based on a series of laboratory-scale percolation experiments, the variations in bacterial community diversity, composition, and structure were investigated during simulated geothermal water recharge using high-throughput sequencing technology. The Chao, Shannon, and Evenness indexes were used to quantify the richness, diversity, and evenness of the bacterial community, respectively. The results show that the richness of the bacterial community initially increased and then decreased in the sand columns during the experiments of geothermal water recharge, while the changes in bacterial diversity and evenness were not apparent. A variety of bacterial phyla were found, among which Proteobacteria was predominant (88.31%), followed by Actinobacteria, Bacteroidetes, and Firmicutes (4.23%, 3.44%, and 2.49%). For the non-Proteobacterial phyla, Actinobacteria gradually disappeared while Bacteroidetes and Firmicutes were detected during the percolation experiments. This study implies that, despite the variations in the bacterial community, a core group of bacteria persists during geothermal water recharge, and thus a targeted control of bacteria-induced clogging during geothermal water recharge should be feasible.

Spa environments in central Serbia: Geothermal potential, radioactivity, heavy metals and PAHs.

This study aims to estimate geothermal potential, radioactivity levels, and environmental pollution of six most popular spas in Central Serbia (Ovcar, Gornja Trepca, Vrnjacka, Mataruska, Bogutovacka and Sokobanja), as well as to evaluate potential exposure and health risks for living and visiting population. Thermal possibilities of the studied spas showed medium and low geothermal potential with total thermal power of 0.025 MW. Gamma dose rates in air varied from 63 to 178 nSv h-1. Specific activities of natural radionuclides (226Ra, 232Th and 40K) and 137Cs in soil were measured; annual effective doses and excess lifetime cancer risk from radionuclides were calculated. Radon concentration in thermal-mineral waters from the spas ranged between 1.5 and 60.7 Bq L-1 (the highest values were measured in Sokobanja). The annual effective dose from radon due to water ingestion was calculated. The analyzed soils had a clay loam texture. The presence of As, Cr, Cu, Fe, Mn, Ni, Pb, Cd, Zn, and Hg in soil was investigated. The concentrations of As, Cr, Ni, and Hg exceeded the regulatory limits in many samples. Soil samples from Mataruska spa were generally the most contaminated with heavy metals, while the lowest heavy metal concentrations were observed in Sokobanja. Health effects of exposure to heavy metals in soil were estimated by non-carcinogenic risk and carcinogenic risk assessment. Total carcinogenic risk ranged between 6 × 10-4 and 137 × 10-4 for children and between 0.1 × 10-4 and 2.2 × 10-4 for adults. The sum of 16 PAHs analyzed in soil samples varied from 92 to 854 µg kg-1.

Utilización de las aguas del balneario Villa de Olmedo / Use of mineral waters at Villa de Olmedo spa

Se exponen aspectos generales del Balneario Villa de Olmedo (Valladolid), modernas instalaciones dentro de un edificio antiguo, y se hace referencia a las posibles acciones sobre el organismo humano de sus aguas, que son: hipotermales, de mineralización fuerte, clorurado sódicas, muy blandas. Se indican los programas que se ofrecen y las técnicas utilizadas, según información suministrada por el balneario

General aspects of this singular ancient building with modern installations at the Villa de Olmedo Spa (Valladolid) will be exposed. The mineral water used at this Spa and its possible actions on the human body will be indicated. These waters are hypothermal, have a strong mineralization, mostly with sodium chloride, and are very soft. The programmes offered, and the techniques used will be indicated according to the information supplied

[Spa facilities and legionellosis: legislative structure and state of the art in Apulia (Italy)]. / Strutture termali e legionellosi: quadri normativi e stato dell'arte in Puglia.

A number of factors, for example water temperature, can encourage the growth of microorganisms such as Legionella spp in spa facilities. Individuals who attend this type of facility are often subjects at risk for infection who are undergoing inhalation therapy and hot tub treatments. A very accurate management of these facilities is therefore required to avoid infection by Legionella spp. The purpose of this study was to verify the current Italian national and Apulia regional legislation regarding the control of contamination by Legionella spp. in spa facilities.

Onsen (hot springs) in Japan--transforming terrain into healing landscapes.

Japan is situated on the Pacific fire rim and has a large number of hot springs (onsens). There are over 27,000 sources of such springs and the country has a well regulated system of onsens. Within this geographical and cultural peculiarities certain unique traditional health practices have evolved, prominent among which is Touji or onsen therapy. The article highlights various healing practices surrounding onsens, institutionalization of these practices, current policy regulations, standards and their contemporary challenges. This research used publicly available information from literature sources and data through expert interviews. It draws attention to the fact that touji has been marginalized in the recent health policies. The study highlights that onsen as a therapeutic landscape has an important role in maintaining health and wellbeing in the country and holds immense value in building social cohesion in local communities. The study points to the need for appropriate studies on the social and symbolic healing elements related to onsen landscapes, as well as the need for developing a comprehensive strategy for strengthening their culturally specific health management roles.

Isolation and identification of Acanthamoeba species from thermal spring environments in southern Taiwan.

Acanthamoeba species are free-living amoebae found in a range of environments. Within this genus, a number of species are recognized as human pathogens, potentially causing Acanthamoeba keratitis, granulomatous amoebic encephalitis, and chronic granulomatous lesions. In this study, 60 water samples were taken from four thermal spring recreation areas in southern Taiwan. We detected living Acanthamoeba spp. based on culture-confirmed detection combined with the molecular taxonomic identification method. Living Acanthamoeba spp. were detected in nine (15%) samples. The presence or absence of Acanthamoeba spp. in the water samples depended significantly on the pH value. The most frequently identified living Acanthamoeba genotype was T15 followed by T4, Acanthamoeba spp., and T2. Genotypes T2, T4, and T15 of Acanthamoeba, are responsible for Acanthamoeba keratitis as well as granulomatous amoebic encephalitis, and should therefore be considered a potential health risk associated with human activities in thermal spring environments.

Water quality parameters associated with prevalence of Legionella in hot spring facility water bodies.

Some species of Legionella are recognized as opportunistic potential human pathogens, such as Legionella pneumophila, which causes legionnaires disease. Indeed, outbreaks of legionellosis are frequently reported in areas in which the organism has been spread via aerosols from contaminated institutional water systems. Contamination in hot tubs, spas and public baths are also possible. As a result, in this study, we investigated the distribution of Legionella at six hot spring recreation areas throughout Taiwan. Legionella were detected in all six hot spring recreation areas, as well as in 20 of the 72 samples that were collected (27.8%). Seven species of Legionella identified from samples by the direct DNA extraction method were unidentified Legionella spp., Legionella anisa, L. pneumophila, Legionella erythra, Legionella lytica, Legionella gresilensis and Legionella rubrilucen. Three species of Legionella identified in the samples using the culture method were L. pneumophila, unidentified Legionella spp. and L. erythra. Legionella species were found in water with temperatures ranging from 22.7 °C to 48.6 °C. The optimal pH appeared to range from 5.0 to 8.0. Taken together, the results of this survey confirmed the ubiquity of Legionella in Taiwan spring recreational areas. Therefore, a long-term investigation of the health of workers at hot spring recreational areas and the occurrence of Legionella in hot spring recreational areas throughout Taiwan are needed.

Fe-Si biominerals in the Vilyuchinskie hot springs, Kamchatka Peninsula, Russia.

The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchinskaya hydrothermal system, Kamchatka Peninsula, Russia, were investigated. The Vilyuchinskie hot springs had a discharge temperature of 55-56 degrees C and Na-Ca-HCO3-type waters rich in silicic and boric acids. Water and biomats had high concentrations of Fe, Mn, Sr, and As. Enumeration of total bacterial abundance (TBA) demonstrated a low density of bacterial populations. However, the fractions of metabolically active bacteria and respiring iron-oxidizing bacteria in the hot-spring water were high, comprising 68 and 21% of TBA, respectively. Scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDX) showed that unicellular rod-shaped bacteria about 5-microm long predominated in the brown biomats. The mineral capsules of these bacteria contained large amounts of Fe and Si. Extracellular and intracellular particles were observed by transmission electron microscopy. Fe-oxidizing bacteria were isolated from the biomats on agar plates with selective medium. Therefore, it can be concluded that microorganisms inhabiting the biomats of the Vilyuchinskie hot springs are essential for the deposition of Fe-minerals at neutral pH.