RESUMEN

Numerous reservoirs encounter challenges related to taste and odor issues, often attributed to odorous compounds such as geosmin (GSM) and 2-methylisoborneol (2-MIB). In this study, two large reservoirs located in northern and southern China were investigated. The Jinpen (JP) reservoir had 45.99 % Actinomycetes and 14.82 % Cyanobacteria, while the Xikeng (XK) reservoir contained 37.55 % Actinomycetes and 48.27 % Cyanobacteria. Most of the 2-MIB produced in surface layers of the two reservoirs in summer originated from Cyanobacteria, most of the 2-MIB produced in winter and in the bottom water originated from Actinomycetes. Mic gene abundance in the XK reservoir reached 5.42 × 104 copies/L in winter. The abundance of GSM synthase was notably high in the bottom layer and sediment of both reservoirs, while 2-MIB synthase was abundant in the surface layer of the XK reservoir, echoing the patterns observed in mic gene abundance. The abundance of odor-producing enzymes in the two reservoirs was inhibited by total nitrogen, temperature significantly influenced Actinomycetes abundance in the JP reservoir, whereas dissolved oxygen had a greater impact in the XK reservoir. Overall, this study elucidates the molecular mechanisms underlying odor compounding, providing essential guidance for water quality management strategies and the improvement of urban water reservoir quality.

Asunto(s)

Canfanos , Agua Potable , Naftoles , Odorantes , Gusto , Odorantes/análisis , Agua Potable/microbiología , China , Actinobacteria/genética , Cianobacterias/genética , Abastecimiento de Agua , Microbiología del Agua , Contaminantes Químicos del Agua/análisis , Estaciones del Año , Monitoreo del Ambiente

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In the sub-Saharan region of Africa, access to safe drinking water remains limited in many countries. This study provides an overview of the quality of surface water and groundwater in rural and peri-urban areas of Madagascar, Uganda, and Rwanda. Selected physico-chemical parameters, inorganic species (including inorganic ions), and organic pollution indicators, such as total organic carbon, non-ionic surfactants, cationic surfactants, anionic surfactants, sum of phenolic compounds and formaldehyde, were analysed. Principal component analysis was applied to assess the variability of the water quality and identify regional dependencies. The inorganic ion composition in the majority of the studied samples meets WHO and EU requirements for drinking water intended for human consumption and poses no human health risk. However, an individual non-cancer-causing health index for nitrates and the values of Water Quality Index show a possible threat of ingesting the studied drinking water. The presence of surfactants (0.1-0.65 mgL-1), phenolic compounds (0.025-1.76 mgL-1) and formaldehyde (0.04-0.32 mgL-1) may also pose a risk to human, animal, and aquatic life. Additionally, in-situ measurements for E. coli and Total Coliforms conducted during the last field campaign in Madagascar (2022) revealed that all studied drinking water sources ranged from intermediate risk to unsafe. This result calls for the urgent need to enhance WASH (water, sanitation, and hygiene) services in the studied areas. The presence of both chemical and microbiological pollutants shows the need for the local authorities to develop and implement a catchment management plan to ensure the protection of water resources from potential pollution, and raise community awareness about the impact of human activity on water resources.

Asunto(s)

Agua Potable , Monitoreo del Ambiente , Calidad del Agua , Madagascar , Agua Potable/química , Rwanda , Uganda , Contaminantes Químicos del Agua/análisis , Humanos , Abastecimiento de Agua

RESUMEN

Raphidiopsis raciborskii (R. raciborskii) forms harmful cyanobacterial blooms globally, and poses a great threat to the safety of drinking water and public health. There is a great need to develop eco-friendly biological alternative measures to mitigate mass blooms of R. raciborskii. However, previous rare studies on algicidal microorganisms against R. raciborskii restricted this aim. Recently, an algicidal bacterium Streptomyces sp. HY (designated HY) was identified with flavones producing ability, and could remove up to 98.73 % of R. raciborskii biomass within 48 h by directly attacking the cyanobacterium and release of algicidal substances (i.e., flavonoids) with a inoculum ratio of 5 %. Algicidal rate of HY was enhanced by 88.05 %, 89.33 % under dark and light, and full-light conditions respectively, when compared with the dark condition. Its algicidal substances were stable in a broad range of temperature (-80-55 °C) and pH (3-11) conditions, and all treated groups exhibited ≈ 100 % algicidal rate at day 3. HY treatment disrupted the photosynthesis system and triggered serious oxidative stress resulting in severe morphological injury. Thereby, HY treatment significantly affected expression levels of several essential genes (i.e., psbA, psaB, rbcL, ftsZ, recA, grpE), and simultaneously inhibited the biosynthesis and release of cylindrospermopsin. Yet, HY treatment didn't show any toxicity to zebrafish test embryos. Such results indicate that HY is a promising algicidal candidate strain to control global R. raciborskii blooms, and holds great promises for an effective biological measure to sustain water safety.

Asunto(s)

Floraciones de Algas Nocivas , Streptomyces , Pez Cebra , Streptomyces/metabolismo , Floraciones de Algas Nocivas/efectos de los fármacos , Animales , Floculación , Flavonoides/toxicidad , Embrión no Mamífero/efectos de los fármacos , Flavonas/toxicidad , Flavonas/farmacología , Flavonas/química , Cianobacterias

RESUMEN

In June 2022, a gastroenteritis outbreak occurred in a town in Northern Italy, possibly associated with the ingestion of norovirus from public drinking water. Noroviruses are highly infectious RNA viruses, with high stability in the environment. They are the primary cause of non-bacterial gastroenteritis worldwide, and despite the fact that the disease is mainly self-limiting, norovirus infection can lead to severe illness in the immunocompromised, the elderly and children. Immediately after the notification of the suspected norovirus outbreak, faecal specimens were collected from hospitalised patients, and water samples were collected from public drinking fountains in the affected area, to confirm the presence of norovirus. Norovirus was detected in 80 % (95 % CI 0.58-0.91) of the faecal specimens, and in 50 % (95 % CI 0.28-0.72) of the water samples using RT (reverse transcription) Real-time PCR. The identification of GII genotype in all samples confirmed public drinking water as the source of norovirus contamination. In addition, in one faeces and one water sample, the co-presence of genotypes GI and GII was detected. The strains were typed by sequencing, with most of them belonging to the genotype GII.3. Immediately after the confirmation of norovirus contamination in public drinking water, the local competent authorities applied safety measures, resulting in a decline in number of cases. Moreover, after the application of disinfection protocols in the water plant, the sampling was repeated with negative results for norovirus in the affected area. However, positive samples were found in the neighbouring area (prevalence 10.00 %, 95 % CI 0.02-0.40) and in the water spring (prevalence 50.00 %, 95 % CI 0.21-0.78), suggesting norovirus persistence and spread from the water source. The prompt identification of the source of contamination, and collaboration with the local authorities guided the implementation of proper procedures to control viral spread, resulting in the successful control of the outbreak.

RESUMEN

New Zealand's coastal blue spaces, from harbours to beaches, provide diverse wellbeing benefits but can also be sites of danger, fear, and cultural contestation. This qualitative research focuses on Chinese migrants in Auckland, a community who are underrepresented in coastal recreation and overrepresented in drowning statistics. Findings show Chinese migrants dis/connection with coastal blue space and fear of coastal swimming, derived from their homeland habitus and lack of coastal 'blue space' cultural capital. Our research contributes to the growing recognition of 'hydrophobia', and how the racialisation of leisure space impacts the potential for blue spaces and practices to be therapeutic.

Asunto(s)

Emigrantes e Inmigrantes , Miedo , Natación , Humanos , Nueva Zelanda , Masculino , Femenino , Emigrantes e Inmigrantes/psicología , China/etnología , Adulto , Miedo/psicología , Natación/psicología , Investigación Cualitativa , Persona de Mediana Edad , Ahogamiento , Pueblos del Este de Asia

RESUMEN

BACKGROUND: The RNLI "Float to Live" campaign is based on research conducted in indoor pools with experienced open water swimmers. Study 1 investigated whether the RNLI "Float to Live" guidance would enable less experienced individuals to float in realistic open water conditions. Study 2 examined the separate effects of practice and coaching on floating competence. METHODS: Study 1: Inexperienced water users conducted floats in either still, open fresh (n = 22) or open sea water (n = 13), followed by moving sea (n = 6) or fresh water (n = 5). Participants undertook three 2-min floats in still water wearing swimwear and one clothed float: 1) naïve; 2) following RNLI "Float to live" messaging; 3) individual float coaching; 4) simulated fall wearing summer clothing. In moving sea water, participants undertook two floats equivalent to Floats 3 and 4. In moving fresh water, participants undertook 3 floats: 1) naïve; 2) following "defensive floating" coaching; 3) simulated fall wearing summer clothing. Study 2: Two groups matched for skinfold thickness undertook three 2-min floats in a flume wearing swimwear. PRAC group (n = 12): 1) naïve; 2) following float practice; 3) float coaching; COACH group (n = 11) coaching followed by practice. Floating difficulty, confidence, competence, "efficiency" and perceived exertion were analysed using either a Friedman test or mixed model ANOVA. RESULTS: In both fresh water and sea water, participants' floating competence and confidence increased after viewing the RNLI messaging, it was further improved with individualised float coaching. The additional helpful instructions included: 1) "head back with ears submerged"; 2) "relax"; 3) "breathe normally"; 4) "it is OK if your legs sink"; 5) an accurate description of sculling for "active" floaters that needed it; 6) spread arms and legs for stability. The simulated fall with clothing did not impair floating competence. No difference in floating competence was seen between PRAC and COACH, though confidence may be increased sooner in COACH. CONCLUSIONS: The RNLI float advice can be applied in realistic open water settings by less experienced water users. Additional content could be included to make the messaging even more effective.

Asunto(s)

Natación , Humanos , Masculino , Femenino , Adulto , Piscinas , Adulto Joven , Agua Dulce

RESUMEN

Adolescents aged 15 to 19 years have the second highest fatal drowning rate of any age group, second only to toddlers aged 12 to 36 months. This risk is amplified in black, indigenous, and people of color (BIPOC), and those of low socioeconomic status. Worcester, MA is a diverse city with over 40% of residents identifying as BIPOC and 20% living below the poverty line. The city has multiple natural bodies of water available for recreation, putting Worcester residents, particularly adolescents, at high risk of drowning. It is known that swimming lessons provided to adolescents significantly improve their swimming skills, however many programs are tailored to young children and are not appropriate for adolescents. Students from the University of Massachusetts T.H. Chan Medical School (UMass Chan), in collaboration with community partners, developed a water safety and swim education program tailored to Worcester adolescents as a means for an age-appropriate swim experience and education, community engagement, and injury prevention. Water Safe Worcester (WSW) was established as a city-wide injury prevention program that included swim lessons offered by medical students at the Central Community Branch YMCA in Worcester, MA. Instructors included UMass Chan medical students, graduate students, and staff. Adolescent YMCA members were invited to participate in lessons free of charge. Lessons were 90 min and emphasized a 3-fold approach: (1) expand knowledge of water safety and what to do in an emergency, (2) increase swimming skills, and (3) reduce fear of water. The overall attendance for the 2023 spring and summer sessions offered was 73 students, including multiple swimmers who attended more than one session. A total of 12 volunteers participated, which included 9 first-year medical students, one PhD student, one research assistant, and one surgery resident from UMass Chan. WSW demonstrated promising outcomes during its swim education classes, suggesting that WSW is a successful model to promote water safety, reduce the risk of drowning, and expand access to life-saving skills to Worcester's at-risk adolescents. This program serves as a critical step toward health equity while also providing an avenue for public health and injury prevention exposure for medical students.

Asunto(s)

Ahogamiento , Natación , Humanos , Adolescente , Ahogamiento/prevención & control , Natación/estadística & datos numéricos , Femenino , Masculino , Massachusetts , Adulto Joven , Poblaciones Vulnerables , Estudiantes/estadística & datos numéricos

RESUMEN

Introduction: Microbial contamination of drinking water, particularly by pathogens such as Escherichia coli O157: H7, is a significant public health concern worldwide, especially in regions with limited access to clean water like the Gaza Strip. However, few studies have quantified the disease burden associated with E. coli O157: H7 contamination in such challenging water management contexts. Objective: This study aimed to conduct a comprehensive Quantitative Microbial Risk Assessment to estimate the annual infection risk and disease burden attributed to E. coli O157: H7 in Gaza's drinking water. Methods: Applying the typical four steps of the Quantitative Microbial Risk Assessment technique-hazard identification, exposure assessment, dose-response analysis, and risk characterization-the study assessed the microbial risk associated with E. coli O157: H7 contamination in Gaza's drinking water supply. A total of 1317 water samples from various sources across Gaza were collected and analyzed for the presence of E. coli O157: H7. Using Microsoft ExcelTM and @RISKTM software, a Quantitative Microbial Risk Assessment model was constructed to quantify the risk of infection associated with E. coli O157: H7 contamination. Monte Carlo simulation techniques were employed to assess uncertainty surrounding input variables and generate probabilistic estimates of infection risk and disease burden. Results: Analysis of the water samples revealed the presence of E. coli O157: H7 in 6.9% of samples, with mean, standard deviation, and maximum values of 1.97, 9.74, and 112 MPN/100 ml, respectively. The risk model estimated a median infection risk of 3.21 × 10-01 per person per year and a median disease burden of 3.21 × 10-01 Disability-Adjusted Life Years per person per year, significantly exceeding acceptable thresholds set by the WHO. Conclusion: These findings emphasize the urgent need for proactive strategies to mitigate public health risks associated with waterborne pathogens in Gaza.

RESUMEN

The rise in cyanobacterial blooms due to eutrophication and climate change has increased cyanotoxin presence in water. Most current water treatment plants do not effectively remove these toxins, posing a potential risk to public health. This study introduces a water treatment approach using nanostructured beads containing magnetic nanoparticles (MNPs) for easy removal from liquid suspension, coated with different adsorbent materials to eliminate cyanotoxins. Thirteen particle types were produced using activated carbon, CMK-3 mesoporous carbon, graphene, chitosan, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidised cellulose nanofibers (TOCNF), esterified pectin, and calcined lignin as an adsorbent component. The particles' effectiveness for detoxification of microcystin-LR (MC-LR), cylindrospermopsin (CYN), and anatoxin-A (ATX-A) was assessed in an aqueous solution. Two particle compositions presented the best adsorption characteristics for the most common cyanotoxins. In the conditions tested, mesoporous carbon nanostructured particles, P1-CMK3, provide good removal of MC-LR and Merck-activated carbon nanostructured particles, P9-MAC, can remove ATX-A and CYN with high and fair efficacy, respectively. Additionally, in vitro toxicity of water treated with each particle type was evaluated in cultured cell lines, revealing no alteration of viability in human renal, neuronal, hepatic, and intestinal cells. Although further research is needed to fully characterise this new water treatment approach, it appears to be a safe, practical, and effective method for eliminating cyanotoxins from water.

Asunto(s)

Toxinas Bacterianas , Toxinas de Cianobacterias , Toxinas Marinas , Microcistinas , Purificación del Agua , Toxinas de Cianobacterias/química , Humanos , Microcistinas/toxicidad , Microcistinas/química , Microcistinas/aislamiento & purificación , Toxinas Marinas/toxicidad , Toxinas Marinas/química , Toxinas Marinas/aislamiento & purificación , Purificación del Agua/métodos , Adsorción , Toxinas Bacterianas/toxicidad , Toxinas Bacterianas/química , Toxinas Bacterianas/aislamiento & purificación , Alcaloides/química , Alcaloides/toxicidad , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/toxicidad , Tropanos/química , Tropanos/toxicidad , Tropanos/aislamiento & purificación , Nanoestructuras/química , Nanoestructuras/toxicidad , Uracilo/análogos & derivados , Uracilo/química , Uracilo/toxicidad , Cianobacterias/química , Supervivencia Celular/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/química

RESUMEN

Introduction: Although previous research has examined the risk factors for drowning behavior among adolescents, it is unclear whether this association is influenced by water safety knowledge. This study aimed to examine whether water safety knowledge is associated with adolescents' drowning risk behaviors and whether drowning risk perceptions and attitudes could have a chain mediating role in the association between water safety knowledge and adolescents' drowning risk behaviors. Methods: This study included 7,485 adolescents from five Chinese provinces and cities. We used the Drowning Risk Behaviors Scales (DRBS) to evaluate the risk of drowning behaviors. The Water Safety Knowledge Scale (WSKS) was used to evaluate the competence level of water safety knowledge. The Drowning Risk Perceptions Scale (DRPS) was used to evaluate the risk level of perceptions, and the Drowning Risk Attitudes Scale (DRAS) was used to evaluate the risk level of attitudes. Results: The results of the mediating effect test showed that water safety knowledge (WSK) affected drowning risk behaviors (DRB) through three indirect paths. Drowning risk perceptions (DRP) and attitudes (DRA) have significantly mediated the association between WSK and DRB. In conclusion, DRP and DRA can act as mediators between WSK and DRB, not only individually, but also as chain mediators, where the direct effect is-0.301, the total indirect effect is-0.214, and the total mediated indirect effect is 41.5%. Discussion: Water safety knowledge negatively predicts adolescents' drowning risk behaviors; water safety knowledge has an inhibitory effect on drowning risk perceptions. Water safety knowledge can directly influence adolescents' drowning risk perceptions and indirectly affect drowning risk behaviors through the mediation of drowning risk perceptions and attitudes comprising three paths: (1) the drowning risk perceptions mediation path, (2) the drowning risk attitudes mediation path, and (3) the drowning risk perceptions and attitudes mediation paths.

Asunto(s)

Ahogamiento , Conocimientos, Actitudes y Práctica en Salud , Asunción de Riesgos , Humanos , Ahogamiento/prevención & control , Adolescente , Femenino , Masculino , China , Encuestas y Cuestionarios , Factores de Riesgo , Seguridad , Conducta del Adolescente/psicología

RESUMEN

In Victoria, Australia, culturally and linguistically diverse communities are more than twice as likely to drown than their Australian-born counterparts. One explanation is the lack of feasible, community-led approaches to water safety and swimming education. A community engagement framework was used to develop and implement a 5-day pool program to teach swimming and water safety to newly arrived migrant children attending an English language school in Victoria. Socio-cultural needs of the predominantly Afghan cohort were incorporated through in-language consultation with parents who requested males and females be educated separately. Participants were assessed against Victorian aquatic competency benchmark standards at pre- and post-program, however, there was no expectation to achieve these competencies within the 5 days due to a lack of prior aquatic exposure. Independent and paired samples t-tests determined changes in skills, including by sex and number of lessons attended. Forty-one participants completed all assessments. Excluding lifesaving skills, there was a significant increase in total competency attainment overall from pre- to post-program (p < 0.001), and for each competency (p's ≤ 0.002)-predominantly knowledge and rescue skills. Improvements were mostly recorded among males, demonstrating that females may require more specialized support to achieve similar outcomes. Improvements in rescue skills and knowledge indicate the program's effectiveness in increasing newly arrived migrant children's awareness of, and exposure to, foundations of safe aquatic behaviours. Future programs tailored to newly arrived migrant communities should consider implementing water familiarization activities as a stepping stone to engagement with structured swimming and water safety education.

Asunto(s)

Natación , Niño , Femenino , Humanos , Masculino , Pueblos de Australasia , Ahogamiento/prevención & control , Educación en Salud , Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud/métodos , Seguridad , Victoria , Emigrantes e Inmigrantes

RESUMEN

The main aim of this study is to evaluate the performance of a single slope solar still and to assess the effect of nanofluid on its performance. A single basin single slope solar still was designed and fabricated at the Department of Chemical Engineering, IET Lucknow. Its performance was assessed in terms of the yield of potable water. The effect of various climatic parameters was also studied. Al2O3 nanofluid was used to enhance the yield of the solar still. In the presence of nanofluid, the total yield of the solar still improved by 16.6%. Its economic feasibility was analyzed and reported. The portability of the small size of solar stills, its better economics, easy fabrication, and good performance make them very useful for industrial as well as household purposes.

RESUMEN

Background: Modena's Local Health Authority (AUSL) is a public service with more than 5,000 employees. In its facilities, drinking water is available as tap water. However, disposable plastic bottles are also widely used, thus increasing plastic waste. Study design and methods: In the present study, we aimed to investigate employees' drinking habits through an ad hoc 10-item online questionnaire, which was administered in spring 2023. Results: Of the 584 participants (10.8% response rate), 75% of workers reported drinking less than 1.5 liters of water per day. In addition, 74% of workers brought water from home, while 62% used disposable plastic containers bought in the workplace or outside. When asked if they would appreciate a water refilling station in the workplace, whether that would induce them to consume less plastic and to drink more water, 91%, 82%, and 72% of workers said "yes", respectively. By installing water coolers, the estimated mean number of plastic bottles spared every day at the AUSL would be about 6,000. Conclusions: Our data shed light on most employees' perceived need for alternative sources of drinking water, not only in order to drink more for health benefits, but also to reduce plastic usage in favor of reusable, more environmentally friendly materials.

RESUMEN

In its recent development, the Pictorial Scale of Perceived Water Competence (PSPWC) showed good face and construct validity. However, additional reliability and validity research is needed, including test-retest reliability and a demonstration of the relationship between PSPWEC test scores and actual water competence. Toward that aim, we administered the PSPWC to 124 children, aged 5-8 years. We repeated this test administration after one week for a subset of 55 children to determine its test-retest reliability, and the remaining 69 children also performed the fully aligned Actual Aquatic Skills Test (AAST) in an indoor swimming pool to provide data for our investigation of the relationship between PSPWC scores and actual water competence. We found good test-retest reliability, both at the global level (ICC = 0.81, n = 55) and at the level of individual skills (Weighted kappa coefficients from 0.58 to 0.90), with no significant differences between these two test scores. We also found a moderate positive relationship between PSPWC and AAST total scores (r = .64, n = 69), with no significant difference between total scores of actual and perceived water competencies. Children overestimated their competence in three specific skills: the back star, swimming on the front, and diving in deep water. While these results underline specific situations in which children's higher self-perceptions of their water competence are a risk factor for their water safety, these data confirm that the PSPWC is reliable for measuring children's perceived competencies in aquatic education and drowning prevention, and there is further support for its validity through a moderate correlation with actual water competencies.

Asunto(s)

Natación , Humanos , Niño , Masculino , Femenino , Reproducibilidad de los Resultados , Preescolar , Destreza Motora/fisiología , Psicometría/normas

RESUMEN

The available literature on natural hazard risk analysis focused on the implementation of water safety plans (WSPs) is surprisingly quite poor, despite the significant increase in the number and severity of disasters and adverse effects on drinking water supply systems generated by natural hazards. At the same time, WSPs that conveniently account for natural hazards with a comprehensive approach 'from source to tap' are still scarce as they typically occur at larger spatial scales and adequate prevention, mitigation and adaptation require efficient inter-institutional collaborations. The aim of this paper is to highlight the main bottlenecks for water utilities to include natural hazards in the development of their WSPs. The research adopted a stakeholders-oriented approach, involving a considerable number of water utilities (168), water sectoral agencies (15) and institutions (68) across the Adriatic-Ionian Region through a stepwise process that generated joint SWOT analysis, the development of a decision support system (DSS) focused on WSPs procedures and tabletop exercises. The final outcomes generated strategic documents (REWAS - Adrion Road map for resilient water supply) that highlighted the necessity for efficient cross-sectoral and inter-institutional cooperation in the development of well-founded and robust WSPs to address natural hazard risk analysis for water supply systems (DWSS).

Asunto(s)

Agua Potable , Abastecimiento de Agua , Medición de Riesgo

RESUMEN

Pacific Island Countries (PICs) collectively have the lowest rates of access to safely managed or basic drinking water and sanitation globally. They are also the least urbanised, have dynamic socioeconomic and increasing climate-linked challenges. Community-based water managers need to respond to variability in water availability and quality caused by a range of hazards. Water Safety Planning (WSP), a widely adopted approach to assessing water supply, offers a risk-based approach to mitigating both existing and future hazards. WSP is adaptable, and making modifications to prescribed WSP to adapt it to the local context is common practice. Within the Pacific Community Water Management Plus research project, we used formative research and co-development processes to understand existing local modifications, whether further modifications are required, and, to develop additional modifications to WSP in Fiji, Vanuatu and Solomon Islands. The types of additional local modifications we recommend reflect the unique context of PICs, including adjusting for community management of water supplies and required collective action, community governance systems, levels of social cohesion in communities, and preferred adult-learning pedagogies. Incorporating modifications that address these factors into future WSP will improve the likelihood of sustained and safe community water services in Pacific and similar contexts.

Asunto(s)

Población Rural , Humanos , Adulto , Islas del Pacífico , Vanuatu , Fiji , Melanesia

RESUMEN

INTRODUCTION: Infection with hepatitis A virus (HAV) is often asymptomatic in young children, but most adolescents and adults will have symptoms ranging from nausea and tiredness to acute liver failure and even death. The risk of severe disease is higher in older adults and people with pre-existing liver disease. Immunization is recommended in regions with low HAV endemicity levels, i.e., where people get infected later in life. In the Philippines, recent epidemiologic data on HAV infection are lacking. The objective of this study was to assess age-specific seroprevalence and evaluate risk factors associated with HAV seropositivity. METHODS: People from two geographic areas (urban and rural) were recruited/enrolled and stratified by age group. HAV-specific immunoglobulin G (IgG) antibodies were measured with a chemiluminescent microparticle immunoassay. Sociodemographic parameters, hepatitis medical history, disease knowledge, hygiene measures and sanitation were assessed via a purpose-made questionnaire. Age at midpoint of population immunity (AMPI) was estimated using Kaplan-Meier curves. Logistic regression analyses were carried out to determine factors that were statistically significantly associated (p < 0.05) with HAV seropositivity. RESULTS: Overall, 1242 participants were included in the analysis; 250/602 (41.5%) participants from urban regions and 283/640 (44.2%) participants from rural regions tested positive for HAV IgG antibodies. AMPI was 35 and 37 years for the rural and urban region, respectively. Higher education was associated with lower HAV seropositivity prevalence ratios, while not living in the same region for the last 5 years, regularly consuming street food and lack of handwashing after defecation were associated with a higher likelihood of HAV seropositivity. CONCLUSION: Results suggest that HAV endemicity is low in the Philippines. Factors associated with HAV seropositivity were traveling, consuming street food and lack of basic hygienic gestures. Immunization might be an option to protect vulnerable populations against severe hepatitis A disease.

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Hepatitis A virus (HAV) is transmitted via the fecal-oral route through consumption of contaminated food or water or by close contact with an infected person. In children, HAV is usually of no concern, but in adults and people with existing liver disease, HAV infection can lead to severe symptoms and even death. In areas where most people get hepatitis during childhood (high endemicity), vaccination is not required, since people acquire life-long immunity after infection. In regions with low and intermediate HAV endemicity, people may remain at risk of infection later in life and vaccination could be considered to prevent severe HAV disease and its associated complications. In the Philippines, the current endemicity level is unknown. The goal of this study was to determine the endemicity level in the Philippines and to determine risk factors for HAV infection. We measured the proportion of people (by age group) who had previously been infected with HAV. Results showed that by age of 5 years < 20% of the study population was infected by HAV. By the age of 37 years in the urban population and 35 years in the rural population, 50% of people tested positive for HAV antibodies, indicating previous infection. This means that the Philippines has low HAV endemicity. Risk factors for HAV seropositivity were traveling, regularly eating street food and not washing hands after defecation. Vaccination against HAV might be of benefit in the Philippines, especially early in life to prevent most severe outcomes in adulthood.

RESUMEN

Intensified land use can disturb water quality, potentially increasing the abundance of bacterial pathogens, threatening public access to clean water. This threat involves both direct contamination of faecal bacteria as well as indirect factors, such as disturbed water chemistry and microbiota, which can lead to contamination. While direct contamination has been well described, the impact of indirect factors is less explored, despite the potential of severe downstream consequences on water supply. To assess direct and indirect downstream effects of buildings, farms, pastures and fields on potential water sources, we studied five Swedish lakes and their inflows. We analysed a total of 160 samples in a gradient of anthropogenic activity spanning four time points, including faecal and water-quality indicators. Through species distribution modelling, Random Forest and network analysis using 16S rRNA amplicon sequencing data, our findings highlight that land use indirectly impacts lakes via inflows. Land use impacted approximately one third of inflow microbiota taxa, in turn impacting ∼20-50 % of lake taxa. Indirect effects via inflows were also suggested by causal links between e.g. water colour and lake bacterial taxa, where this influenced the abundance of several freshwater bacteria, such as Polynucleobacter and Limnohabitans. However, it was not possible to identify direct effects on the lakes based on analysis of physiochemical- or microbial parameters. To avoid potential downstream consequences on water supply, it is thus important to consider possible indirect effects from upstream land use and inflows, even when no direct effects can be observed on lakes. Legionella (a genus containing bacterial pathogens) illustrated potential consequences, since the genus was particularly abundant in inflows and was shown to increase by the presence of pastures, fields, and farms. The approach presented here could be used to assess the suitability of lakes as alternative raw water sources or help to mitigate contaminations in important water catchments. Continued broad investigations of stressors on the microbial network can identify indirect effects, avoid enrichment of pathogens, and help secure water accessibility.

Asunto(s)

Sustancias Húmicas , Hierro , Lagos , Legionella , Lagos/microbiología , ARN Ribosómico 16S/genética , Microbiología del Agua , Suecia , Calidad del Agua , Monitoreo del Ambiente

RESUMEN

While plastic water bottles are known to potentially release various volatile organic compounds (VOCs) when exposed to light, existing knowledge in this field remains limited. In this study, we systematically examined the composition, yield, and toxicity of VOCs released from six plastic containers obtained from different continents under UV-A and solar irradiation. After light exposure, all containers released VOCs, including alkanes, alkenes, alcohols, aldehydes, carboxylic acids, aromatics, etc. The 1#, 3#, 4#, 5#, and 6# containers exhibited 35, 32, 19, 24 and 37 species of VOCs, respectively. Specifically, the 2# container released 28 and 32 series of VOCs after 1-day (short-term) and 7-day (long-term) UV-A irradiation, respectively, compared to 30 and 32 species under solar irradiation. Over half of the VOCs identified were oxidized compounds alongside various short-chain hydrocarbons. Significant differences in VOC compositions among the containers were observed, potentially originating from light-induced aging and degradation of the polyethylene terephthalate structure in the containers. Toxicological predictions unveiled distinctive toxic characteristics of VOCs from each container. For example, among the various VOCs produced by the 2# container, straight-chain alkanes like n-hexadecane (544-76-3) were identified as the most toxic compounds. After long-term irradiation, the yield of these toxic VOCs from the 2# container ranged from 0.11 ng/g to 0.79 ng/g. Considering the small mass of a single bottle, the volatilization of VOCs from an individual container would be insignificant. Even after prolonged exposure to light, the potential health risks associated with inhaling VOCs when opening and drinking bottled water appear manageable.

RESUMEN

BACKGROUND AND OBJECTIVE: To increase water safety awareness among young males New Zealand introduced the Swim Reaper program in 2016. The program ran annually over summer and in 2018/19 an evaluation was conducted. The objective of this study was to evaluate the impact of the 2018/19 Swim Reaper social media-based campaign on self-reported water safety awareness and identify changes in fatal and nonfatal drowning rates for New Zealand resident males aged 15-34 years before and after the 2016 Swim Reaper program. METHODS: Online surveys pre (December-2018) and post (February-March-2019) Swim Reaper campaign were used to estimate water safety awareness post-campaign relative to pre-campaign using negative binomial regression adjusted for potential confounders. Interrupted time series (ITS) analysis, adjusted for seasonality, explored changes in drowning mortality, hospital admissions and Accident Compensation Corporation (ACC) claims pre and post program introduction (2016). RESULTS: A total of 518 males responded (50.6% post-campaign). There were significant improvements (post vs. pre-campaign) in self-reported water safety awareness. ITS analysis showed a reduction in drowning related hospital admissions post relative to pre-program (RR = 0.47; [95%CI: 0.24-0.90]; p = 0.02). DISCUSSION: Young males are an at-risk cohort for drowning and creating behavior change among this group can be challenging. Using a unique, humor-based approach the Swim Reaper program appears to be having some impact on self-reported water safety behaviors, as well as unintentional drowning-related hospitalization rates. Further evaluation, more clearly linked to campaign themes, is required to ascertain direct impact of the program. CONCLUSION: The novelty and reach of the campaign within the context of a prevailing downward trend in drownings may provide support for social media-based programs targeting this hard-to-reach demographic.

Asunto(s)

Ahogamiento , Masculino , Humanos , Ahogamiento/epidemiología , Ahogamiento/prevención & control , Nueva Zelanda/epidemiología , Encuestas y Cuestionarios , Morbilidad , Agua