Exploring toilet plume bioaerosol exposure dynamics in public toilets using a Design of Experiments approach.

Bioaerosols generated during toilet flushing can contribute to the spread of airborne pathogens and cross-contamination in indoor environments. This presents an increased risk of fomite-mediated or aerosol disease transmission. This study systematically investigated the factors contributing to increased bioaerosol exposure following toilet flushing and developed an empirical model for predicting the exposure-relevant bioaerosol concentration. Air in a toilet cubicle was sampled by impaction after seeding with Clostridium difficile spores. Design of Experiments (DoE) main effects screening and full factorial design approaches were then employed to investigate the significant factors that heighten the risk of exposure to bioaerosols post-flush. Our findings reveal that the inoculated bacterial concentration (C), time elapsed after flushing (t), lateral distance (d), and mechanical ventilation (v) are significant predictors of bioaerosol concentration, with p-values < 0.05. The interaction term, C × d showed a marked increase in bioaerosol concentration up to 232 CFU/m3 at the closest proximity and highest pathogen load. The interplay of C and t (C × t) demonstrated a time-dependent attenuation of bioaerosol viability, with concentrations peaking at 241 CFU/m3 immediately post-flush and notably diminishing over time. The lateral distance and time post-flush (d × t) interaction also revealed a gradual decrease in bioaerosol concentration, highlighting the effectiveness of spatial and temporal dilution in mitigating bioaerosol exposure risks. Furthermore, there is an immediate rise in relative humidity levels post-flush, impacting the air quality in the toilet environment. This study not only advances our understanding of exposure pathways in determining bioaerosol exposure, but also offers pivotal insights for designing targeted interventions to reduce bioaerosol exposure. Recommendations include designing public toilets with antimicrobial surfaces, optimizing ventilation, and initiating timely disinfection protocols to prioritise surfaces closest to the toilet bowl during peak exposure periods, thereby promoting healthier indoor environments and safeguarding public health in high-traffic toilet settings.

An environmental evaluation of urine-diverting dry toilets in Hiloweyn Camp, Dollo Ado, Ethiopia.

Safe and hygienic management of human waste is essential in humanitarian settings. Urine-diverting dry toilets (UDDTs) can enable this management in some humanitarian emergency settings. A seeded, longitudinal environmental study was conducted in Hiloweyn refugee camp, Dollo Ado, Ethiopia, to measure Escherichia coli and Ascaris suum ova inactivation within closed UDDT vaults and to document environmental conditions (temperature, moisture content, and pH) that could influence inactivation. Hiloweyn camp represented an optimal location for a desiccation-based sanitation technology such as the UDDT. E. coli and Ascaris ova inactivation was observed in UDDTs under warm, dry, alkaline conditions at 6, 9, and 12 months of storage; UDDTs with samples containing <1000 E. coli/g total solids increased from 30 % to 95 % over 12 months, and a >2.8-log10 reduction in Ascaris ova viability was observed after 6 months. Additional laboratory-based studies were conducted to provide insights into the field study findings and study the impact of hydrated lime on E. coli and Ascaris ova inactivation. Results suggest that adding hydrated lime to elevate pH > 12 may increase inactivation and decrease storage time. Overall, UDDTs could contribute to the safe and hygienic management of human waste in comparable warm and dry humanitarian settings.

The Occupational and Environmental Hazards of Uncovered Toilets.

ABSTRACT: Substantial evidence demonstrates that plumes from uncovered toilets potentially expose nurses and other health care workers to aerosols containing infectious agents and hazardous drugs, including antineoplastic drugs. Most hospitals in the United States utilize flushometer-type toilets, which operate under high pressure and do not have a permanently attached closure or lid, which is known to reduce the aerosols generated by flushing. This article aims to raise awareness among nurses of the potential exposure risks associated with toilet plume aerosols, so they can educate other health care workers and take part in initiatives to address these risks.

Achieving Carbon Mitigation with Economic Benefits through High-Resolution Analysis of Renewable Resource Integration in Global Coastal Cities.

Coastal regions, home to more than half of the global population and contributing over 50% to the global economy, possess vast renewable resources, such as seawater and solar energy. The effective utilization of these resources, through the seawater-cooled district cooling system (SWDCS), seawater toilet flushing (SWTF), and rooftop solar photovoltaic system (RTPV), has the potential to significantly reduce carbon emissions. However, implementing these technologies in different geographic contexts to achieve the desired carbon and economic outcomes at the city level lacks a clear roadmap. To address this challenge, we comprehensively analyzed 12 coastal megacities worldwide by integrating geospatial building data. Our study evaluated the potential energy savings, carbon mitigation, and levelized carbon abatement costs (LCACs) from a life cycle perspective. The results revealed that using seawater and solar energy within urban boundaries can reduce electricity consumption from 1 to 24% across these cities. The spatial distribution of the LCAC for seawater-based systems exhibited more variation compared to the RTPV. By applying specific LCAC thresholds ranging from 0 to 225 USD/tCO2e, all cities could achieve both carbon reductions and economic benefits. These thresholds resulted in up to 80 million tonnes of carbon emission reductions and 5 billion USD of economic benefits, respectively. Our study provides valuable insights into integrating renewable resource systems, enabling coastal cities to achieve carbon and economic advantages at the city scale simultaneously.

Toilet effluent separation and brown water treatment: Survey and initial feasibility testing in Mexico.

Separation of domestic effluents at the source and the utilization of low-flush toilets offer alternative approaches for developing efficient wastewater treatment systems while promoting energy generation through anaerobic digestion. This study focused on assessing toilet usage in Mexico and exploring the potential of anaerobic co-digestion of brown water (feces) and toilet paper as influential factors in wastewater treatment systems. A survey was conducted on a representative sample of Mexicans to gather information on toilet usage frequency, toilet paper use and disposal practices, as well as the type and quantity of commercial disinfectants and pharmaceutical compounds they use or consume. The survey revealed that per capita toilet paper consumption is 2.9 kg annually, that 58 % of respondents do not dispose used paper in the toilet, and that about 47 % use two to three cleaning and disinfection products. Notably, 97 % of the sampled Mexican population expressed a willingness to transition to more eco-friendly toilet options. Subsequently, in a second step, the anaerobic co-digestion of brown water with toilet paper was evaluated, demonstrating a relatively high production of volatile fatty acids but low methane production. This suggests an efficient hydrolysis/acidogenesis process coupled with restrained methanogenesis, probably due to pH decrease caused by acidogenesis. This study underscores that toilet paper and brown water are potential suitable substrates for anaerobic co-digestion. Furthermore, it sheds light on the behaviors of Mexican society regarding bathroom use and cleaning, contributing to the establishment of foundations for wastewater treatment systems with effluent separation at the source.

Protecting the Antibacterial Coating of Urinal Catheters for Improving Safety.

Catheter-associated urinary tract infections (CAUTI) are among the most common bacterial infections associated with prolonged hospitalization and increased healthcare expenditures. Despite recent advances in the prevention and treatment of these infections, there are still many challenges remaining, among them the creation of a durable catheter coating, which prevents bacterial biofilm formation. The current work reports on a method of protecting medical tubing endowed with antibiofilm properties. Silicone catheters coated sonochemically with ZnO nanoparticles (NPs) demonstrated excellent antibiofilm effects. Toward approval by the European Medicines Agency, it was realized that the ZnO coating would not withstand the regulatory requirements of avoiding dissolution for 14 days in artificial urine examination. Namely, after exposure to urine for 14 days, the coating amount was reduced by 90%. Additional coatings with either carbon or silica maintained antibiofilm activity against Staphylococcus aureus while resisting dissolution in artificial urine for 14 days (C- or SiO2-protected catheters exhibited only 29% reduction). HR-SEM images of the protected catheters indicate the presence of the ZnO coating as well as the protective layer. Antibiofilm activity of all catheters was evaluated both before and after exposure to artificial urine. It was shown that before artificial urine exposure, all coated catheters showed high antibiofilm properties compared to the uncoated control. Exposure of ZnO-coated catheters, without the protective layer, to artificial urine had a significant effect exhibited by the decrease in antibiofilm activity by almost 2 orders of magnitude, compared to unexposed catheters. Toxicity studies performed using a reconstructed human epidermis demonstrated the safety of the improved coating. Exposure of the epidermis to ZnO catheter extracts in artificial urine affects tissue viability compared with control samples, which was not observed in the case of ZnO NPs coating with SiO2 or C. We suggest that silica and carbon coatings confer some protection against zinc ions release, improving ZnO coating safety.

Activity of a foam in preventing rebound of vancomycin-resistant Enterococcus faecium-containing droplets generated from the toilet bowl.

In hospital environments, droplets generated by urination within shared toilets may represent a route of dissemination for bacteria such as vancomycin-resistant Enterococcus faecium (VREfm), which contributes significantly to the burden of hospital-acquired infections. We investigated the potential activity of a foam in preventing the generation of droplets containing Enterococcus spp. during urination. A uniform layer of foam was deposited in the inner walls and at the bottom of an experimental toilet contaminated with suspensions of Enterococcus strains (including a VREfm strain). Human urination was simulated, and colonies of Enterococcus were recovered through a toilet lid where agar plates had been placed. Results showed that the foam was able to suppress production of droplets containing Enterococcus spp. generated by a liquid hitting inner toilet walls. Conversely, Enterococcus colonies were recovered in absence of foam. Moreover, the foam did not show antibacterial activity. We propose a new non-antimicrobial approach aimed at limiting transmission of multidrug-resistant bacteria, particularly in healthcare settings.

Vertical transmission of infectious aerosols through building toilet drainage system: An experimental study.

The building's toilet drainage system has been identified as a potential route for the transmission of SARS-CoV-2 during outbreaks. This study employed agar-fluorescein sodium semi-solid as trace particles to investigate the possibility of vertical transmission of the SARS-CoV-2 in drainage system. In both scenarios, where floor drains were all properly sealed or dried out, simulated faeces containing fluorescein sodium were flushed into the toilet bowl. Air sampling was conducted in each restroom, and differential pressure measurements at the floor drain locations were taken. The experimental results showed that when all floor drains were properly sealed, the differential pressure at each floor drain was 0. The fluorescein sodium-traced aerosol did not transmit through the drainage system to various floors, which significantly reduced the risk of infection for users through this route. However, when all floor drains dried out, toilet users above the neutral pressure layer (NPL) were at a high risk of virus infection. Due to the increasing maximum negative pressure at the floor drain above the NPL with ascending floor levels, users on each floor above the NPL faced an elevated infection risk in restrooms. Specifically, users on the top floor were exposed to infectious aerosols roughly 1.6 times that of the first floor above the NPL. Conversely, owing to the increasing maximum positive pressure at the floor drain below the NPL with descending floor levels, users below the NPL experienced a comparatively lower infection risk. This finding has important implications for understanding the vertical transmission dynamics of SARS-CoV-2 in residential or public building and can inform the development of effective control measures.

Prevention of legionella infections from toilet flushing cisterns.

INTRODUCTION: Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention. METHODS: We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST). RESULTS: Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting. CONCLUSIONS: One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients.

Designing ergonomic toilets and bathrooms for older adults: A study on anthropometric dimensions and recommendations.

AIMS: This study aimed to evaluate the ergonomic design of toilets and bathroom equipment for older adults using anthropometric measurements. DESIGN: This was a descriptive cross-sectional study. METHODS: Data were collected from 2,721 people aged ≥ 65 years in Turkey. Fourteen anthropometric measurements were evaluated. Body dimension characteristics were described using minimum, maximum, and arithmetic means and standard deviations and the 5th, 25th, 50th, 75th, and 95th percentiles. RESULTS: The measurements showed that companies generally do not design bathroom toilet equipment that is suitable for older adults. CONCLUSION: This study provides advice to designers and manufacturers on how to adapt their products to the bathroom according to users' body characteristics in order to increase person-environment fit for older people.

Older Adults' Perceptions About Using Intelligent Toilet Seats Beyond Traditional Care: Web-Based Interview Survey.

BACKGROUND: In contemporary society, age tech (age technology) represents a significant advancement in health care aimed at enhancing patient engagement, ensuring sustained independence, and promoting quality of life for older people. One innovative form of age tech is the intelligent toilet seat, which is designed to collect, analyze, and provide insights based on toileting logs and excreta data. Understanding how older people perceive and interact with such technology can offer invaluable insights to researchers, technology developers, and vendors. OBJECTIVE: This study examined older adults' perspectives regarding the use of intelligent toilet seats. Through a qualitative methodology, this research aims to unearth the nuances of older people's opinions, shedding light on their preferences, concerns, and potential barriers to adoption. METHODS: Data were collected using a web-based interview survey distributed on Amazon Mechanical Turk. The analyzed data set comprised 174 US-based individuals aged ≥65 years who voluntarily participated in this study. The qualitative data were carefully analyzed using NVivo (Lumivero) based on detailed content analysis, ensuring that emerging themes were coded and classified based on the conceptual similarities in the respondents' narratives. RESULTS: The analysis revealed 5 dominant themes encompassing the opinions of aging adults. The perceived benefits and advantages of using the intelligent toilet seat were grouped into 3 primary themes: health-related benefits including the potential for early disease detection, continuous health monitoring, and seamless connection to health care insights. Technology-related advantages include the noninvasive nature of smart toilet seats and leveraging unique and innovative data collection and analysis technology. Use-related benefits include ease of use, potential for multiple users, and cost reduction owing to the reduced need for frequent clinical visits. Conversely, the concerns and perceived risks were classified into 2 significant themes: psychological concerns, which included concerns about embarrassment and aging-related stereotypes, and the potential emotional impact of constant health monitoring. Technical performance risks include concerns centered on privacy and security, device reliability, data accuracy, potential malfunctions, and the implications of false positives or negatives. CONCLUSIONS: The decision of older adults to incorporate intelligent toilet seats into their daily lives depends on myriad factors. Although the potential health and technological benefits are evident, valid concerns that need to be addressed remain. To foster widespread adoption, it is imperative to enhance the advantages while simultaneously addressing and mitigating the identified risks. This balanced approach will pave the way for a more holistic integration of smart health care devices into the routines of the older population, ensuring that they reap the full benefits of age tech advancements.

Health effects and externalities of the popularization of sanitary toilets: evidence from Rural China.

BACKGROUND: This study aimed to assess the impact of the increased prevalence of sanitary toilets in rural areas on the health of rural residents, and whether the popularity thereof has a positive externality. This study investigates whether the broader use of sanitary toilets has had a positive effect on the health of people who do not have access to them. METHODS: Data from the China Family Panel Studies from 2012 to 2014 and a two-way fixed effect model were used to investigate the relationship between the prevalence of village sanitary toilets and the health of rural residents of all ages. RESULTS: The results showed that: (1) the increase in the prevalence of sanitary toilets in villages is conducive to improving the health level of rural residents; (2) the widespread adoption of sanitary toilets in rural areas has improved the health of not only residents with access to these toilets but also residents without access; (3) the health of children is more sensitive to improvements in sanitary conditions of toilets; and (4) there are significant regional differences in the impact of the popularity of sanitary toilets on the health of rural residents. CONCLUSIONS: This study found that the popularity of sanitary toilets has externalities, improving not only the health of residents who use them but also the health of other residents. This study enriches the literature in the field of health effects of sanitation improvement, while providing a reference for developing countries to further enhance the living environment in rural areas. In the future, the popularization of sanitary toilets should be vigorously promoted to reduce the incidence of diseases.

Unlocking the Role of Social Norms: How They Shape Women's Public Toilet Usage in India.

Poor access to toilets has significant impacts on hygiene, health, safety, and well-being. Women in resource-poor areas may not use public toilets because of concerns about personal safety and the disapproval of others. This study examines social beliefs about women's use of public toilets in India, using data from 5,052 households in rural, semi-urban, and urban slum areas of Bihar and Tamil Nadu in 2018. We asked respondents about their beliefs regarding the prevalence of young women aged 16 to 30 years using public toilets alone and whether this behavior was approved of in their community. We also asked about their personal beliefs on this issue. We used hypothetical vignettes to assess perceptions of a young woman's behavior in different settings regarding public toilet usage by women. Our results show that people who believe many women in their community use public toilets alone and approve of it are more likely to have positive beliefs about this behavior. The experimental vignettes suggest a potential causal link between the prevalence and approval of public toilet usage among young women and their likelihood of using it. These findings are consistent across Bihar and Tamil Nadu and the three administrative regions, indicating that interventions aimed at changing social expectations about women's use of public toilets should focus on highlighting community members' usage and approval. Efforts to encourage woman's access to public toilets and services should target shifting beliefs about public toilet usage among women without disapproval from others.

Empowering elderly care with intelligent IoT-Driven smart toilets for home-based infectious health monitoring.

The COVID-19 pandemic highlights the need for effective and non-intrusive methods to monitor the well-being of elderly individuals in their homes, especially for early detection of potential viral infections. Conspicuously, the present paper develops a Multi-scaled Long Short Term Memory (Ms-LSTM) model for the routine health monitoring of elderly patients to detect COVID-19. The proposed method offers home-based health diagnostics through urine analysis by leveraging the IoT-Fog-Cloud paradigm. Mainly, the proposed model constitutes a four-layered architecture: data acquisition, fog layer, cloud layer, and interface layer. Each layer serves distinct functionalities and provides specific services, thereby collectively enhancing the overall effectiveness of the model. The statistical results of the study demonstrate the superior performance of the proposed Ms-LSTM model in comparison to state-of-the-art methods, including Artificial Neural Networks (ANN), K-Nearest Neighbors (K-NN), Support Vector Machine (SVM), Random Forest, and LSTM. Further, the proposed model attains a mean temporal efficiency of 39.23 seconds. It exhibits high reliability (92.97%), stability (70.06%), and predictive accuracy (93.25%).

Discharge of iodine-containing contrast media into the environment - problem analysis and implementation of measures to reduce discharge by means of separation toilets - experience from a pilot project. / Herausforderung Eintrag jodhaltiger Röntgenkontrastmitteln in die Umwelt ­ Problemanalyse sowie Umsetzung erster Maßnahmen zur Reduktion des Eintrags mittels Trenntoiletten ­ Erfahrungen aus einem Pilotprojekt.

PURPOSE: Environmental aspects and sustainability are becoming increasingly important. In addition to energy consumption, the consumption and environmental discharge of contrast agents pose a particular challenge. Because of their desired stability, X-ray contrast agents (XCAs) are deposited in surface water at a rate of up to 400 tons per year. MATERIALS AND METHODS: In a pilot project, a set of measures (installation of specific separation toilets, the establishment of feedback systems, interviews, questionnaires, and observation) was implemented to sensitize patients and staff to the problem of XCAs during outpatient CT examinations and a retention and recovery system for XCAs was evaluated. RESULTS: In the initial baseline phase, a separation toilet with an additional collection system and a feedback/button system was installed. The built-in feedback system indicated that the separation toilets were used by approx. 16 % of patients without measures. In two subsequent intervention phases, accompanying measures significantly (p < 0.01) increased the use of these separation toilets to 21 % and 25 %, respectively. The measures to reduce the discharge of XCAs were positively assessed by both staff and patients. CONCLUSION: Measures to reduce the discharge of XCAs into the environment have a high acceptance among staff and patients. The subsequent installation of separation toilets is one possibility to achieve on-site retention of XCAs. However, this measure is likely to be of high value only if patients stay on site for a correspondingly long time, as is the case in cardiology, for example. KEY POINTS: · The input of X-ray contrast agents into the environment is relevant in light of the quantity. · Measures to reduce the discharge of X-ray contrast agents into the environment have been investigated in pilot projects. · The (subsequent) installation of separation toilets is possible and allows retention of X-ray contrast agents. · This measure is considered useful by patients and staff. · The financing of these measures needs to be clarified. CITATION FORMAT: · Beer M, Schuler J, Kraus E et al. Discharge of iodine-containing contrast media into the environment - problem analysis and implementation of measures to reduce discharge by means of separation toilets - experience from a pilot project. Fortschr Röntgenstr 2023; 195: 1122 - 1127.