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Assessment of integrated personal exposure (PE) to airborne particulate matter (PM) across diverse microenvironments (MEs) over 24 hours under different exposure scenarios is necessary to identify appropriate strategies to improve urban air quality and mitigate the health effects of PM. We carried out a collaborative study in a densely populated city-state (Singapore) to assess the integrated PE to fine particles (PM2.5), ultrafine particles (UFPs) and black carbon (BC) across diverse indoor and outdoor urban MEs, estimate related health risks and make suitable recommendations for healthy living in cities. Two volunteers with different lifestyles participated in the study by tracking their PE to particulate air pollution and the time-activity patterns over 24 hours using portable PM monitoring devices and recording their whereabouts using GPS coordinates. Home, transport and recreation (i.e., food court) MEs represented pollution hotspots of PM2.5 (21.0 μg/m3), BC (3.4 μg/m3) and UFP (33.0 × 103 #/cm3), respectively. Among the different modes of transport used by the participants (walking, cycling, e-scooter, mass rapid transport (MRT), bus, car and taxi), the air pollutants had elevated concentrations while commuting by public transport (bus and MRT) as well as during active modes of transport (walking and cycling). Air-conditioned cars and taxis, equipped with air filtration systems, represented the lowest PE. The health risk assessment revealed that there are potential carcinogenic risks associated with the long-term exposure to elevated levels of PM2.5-bound toxic trace elements. These risks can be mitigated with the introduction of low-carbon and active modes of transport in place of internal combustion engines and the use of indoor air pollution exposure mitigation devices.

Thermal comfort assessment for the built environment has become more available to analysts and researchers due to the proliferation of sensors and subjective feedback methods. These data can be used for modeling comfort behavior to support design and operations towards energy efficiency and well-being. By nature, occupant subjective feedback is imbalanced as indoor conditions are designed for comfort, and responses indicating otherwise are less common. This situation creates a scenario for the machine learning workflow where class balancing as a pre-processing step might be valuable for developing predictive thermal comfort classification models with high-performance. This paper investigates the various thermal comfort dataset class balancing techniques from the literature and proposes a modified conditional Generative Adversarial Network (GAN), comfortGAN, to address this imbalance scenario. These approaches are applied to three publicly available datasets, ranging from 30 and 67 participants to a global collection of thermal comfort datasets, with 1,474; 2,067; and 66,397 data points, respectively. This work finds that a classification model trained on a balanced dataset, comprised of real and generated samples from comfortGAN, has higher performance (increase between 4% and 17% in classification accuracy) than other augmentation methods tested. However, when classes representing discomfort are merged and reduced to three, better imbalanced performance is expected, and the additional increase in performance by comfortGAN shrinks to 1 - 2%. These results illustrate that class balancing for thermal comfort modeling is beneficial using advanced techniques such as GANs, but its value is diminished in certain scenarios. A discussion is provided to assist potential users in determining which scenarios this process is useful and which method works best.

Climate models imply that by 2100 atmospheric CO2 levels could exceed 900 ppm. At these levels, subscribing to current ventilation rates would lead to indoor CO2 levels ≥1,400 ppm, possibly impacting our physiology and other responses. We ran a randomized, within-subject study with 15 participants to examine the physiological effects of 2,5 hour exposure to three CO2 levels: 900 ppm, 1450 ppm (reduced ventilation), and 1450 ppm (pure CO2 added, ventilation same as 900 ppm). End-tidal CO2 and respiration rate across the different exposures were not significantly different. Spirometry parameters reduced significantly from the beginning to the end at reduced ventilation exposure compared to the 900 ppm condition (p

SARS-CoV-2 has been recognized to be airborne transmissible. With the increased transmissibility leading to increasingly reported positive cases, home quarantine is adopted for the infected patients who are not seriously ill. However, the risk of household aerosol transmission is not well studied. We conducted tracer gas experiment to simulate the exhaled virus laden aerosols from a patient under home quarantine situation inside a residential testbed. The Sulphur hexafluoride concentration (SF6,conc) was measured both inside and outside the quarantine room under various scenarios including, (i) air-conditioning (AC) vs natural ventilation (NV), (ii) operation of ceiling fan, and (iii) operation of window exhaust fan. The ratio of outside-to-inside SF6,conc (O/ISF6) was an indicator for potential exposure of occupants in the same household. Our findings showed, without an exhaust fan, the in-room SF6,conc in AC settings was 4 times higher than in the NV scenarios. Meanwhile, we found the exhaust fan was effective in reducing the O/ISF6 in the AC scenarios (with or without ceiling fan), but its function was diminished in the NV setting with ceiling fan. We suspected the effectiveness of exhaust fan was reduced by air infiltration from other window openings in NV situation. Meanwhile, the operation of ceiling fan continuously pushing tracer gas outwards from the quarantine room through the door gap. Our results suggested that natural ventilation with windows open or switching on a window exhaust fan could reduce aerosol transmission risk from the quarantine room. This study provides useful evidence in recommending low risk ventilation strategies for home quarantine situations.

Background: Globally, many healthcare professionals display weight bias and contribute towards weight stigma. However, weight bias of healthcare professionals in Asia is underexplored., Objective: To investigate weight bias of healthcare professionals in Singapore and explore differences between qualified and student healthcare professionals, plus between i) gender, ii) Body Mass Index (BMI) and iii) ethnicity categories., Methods: Healthcare professionals in Singapore engaged in a web-based survey (March 2023). Participants answered general categorical questions, plus two explicit weight bias outcomes (Fat Phobia Scale and Antifat Attitudes questionnaire). Descriptive statistics summarize outcome findings. Factors associated with degree of weight bias were explored between categories (i.e. student vs qualified, plus gender, BMI and ethnicity categories). Significance was set at p = <0.05., Results: Fifty-five percent of participants (n = 294/525) were qualified healthcare professionals. Mean Fat Phobia Scale score (/5) was 3.19 ± 0.20 (range 2.00-3.86) and total Antifat Attitudes questionnaire score (/9) was 3.20 ± 1.25 (range 0.00-6.85). No significant differences were observed between categories for the Fat Phobia Scale. For the Antifat Attitudes questionnaire, those with underweight BMI's had lower total scores compared to those with healthy (2.54 vs 3.23, MD -0.70) or overweight (2.54 vs 3.41, MD -0.87) BMI's. No other differences in total Antifat Attitudes Scores were observed. However, differences did exist in Antifat Attitude subdomain scores between gender and ethnicity categories., Conclusion(s): Qualified and student healthcare professionals in Singapore display comparable levels of explicit weight bias. This may lead to stigma, and subsequent inequalities in, and poorer provision of, care for people living with overweight and obesity., Competing Interests: Declaration of Competing Interest Nil to declare for all authors., (Copyright © 2024 Asia Oceania Association for the Study of Obesity. All rights reserved.)

Purpose of Review: The approval of resmetirom brings great hope to patients with metabolic dysfunction-associated steatohepatitis (MASH). The purpose of this review is to explore its impact on the global health environment. The implementation of multidisciplinary management MASH is proposed., Recent Findings: Resmetirom has benefits in the treatment of MASH, and its safety and effectiveness have been studied. The adverse events (AEs) need to be noticed. To improve patient outcomes, a multimodal approach with medication such as resmetirom, combined with metabolic and bariatric surgery (MBS) and lifestyle interventions can be conducted. MASH, a liver disease linked with obesity, is a challenging global healthcare burden compounded by the absence of any approved pharmacotherapy. The recent conditional approval by the Food and Drug Administration (FDA) in the United States of resmetirom, an oral, liver-directed, thyroid hormone receptor beta-selective agonist, marks a significant milestone, offering a treatment option for adults with non-cirrhotic MASH and who have moderate to advanced liver fibrosis. This narrative review discusses the efficacy and safety of resmetirom and its role in the therapeutic landscape of MASH treatment. Despite the promising hepatoprotective effect of resmetirom on histological liver endpoints, its use need further research, particularly regarding ethnic differences, effectiveness and cost-effectiveness, production scalability, social acceptance and accessibility. In addition, integrating resmetirom with other multidisciplinary therapeutic approaches, including lifestyle changes and MBS, might further improve clinical liver-related and cardiometabolic outcomes of individuals with MASH. This review highlights the importance of a comprehensive treatment strategy, supporting continued innovation and collaborative research to refine treatment guidelines and consensus for managing MASH, thereby improving clinical patient outcomes in the growing global epidemic of MASH. Studies done to date have been relatively short and ongoing, the course of the disease is highly variable, the conditions of various patients vary, and given this complex clinical phenotype, it may take many years of clinical trials to show long-term benefits., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To identify perceptions and attitudes among people with obesity (PwO) and healthcare professionals (HCPs) toward obesity and its management in nine Asia-Pacific (APAC) countries, a cross-sectional online survey was conducted among adult PwO with self-reported body mass index of ≥25 kg/m 2 (≥27 kg/m 2 , Singapore), and HCPs involved in direct patient care. In total, 10 429 PwO and 1901 HCPs completed the survey. Most PwO (68%) and HCPs (84%) agreed that obesity is a disease; however, a significant proportion of PwO (63%) and HCPs (41%) believed weight loss was the complete responsibility of PwO and only 43% of PwO discussed weight with an HCP in the prior 5 years. Most respondents acknowledged that weight loss would be extremely beneficial to PwO's overall health (PwO 76%, HCPs 85%), although nearly half (45%) of PwO misperceived themselves as overweight or of normal weight. Obesity was perceived by PwO (58%) and HCPs (53%) to negatively impact PwO forming romantic relationships. HCPs cited PwOs' lack of interest (41%) and poor motivation (37%) to lose weight as top reasons for not discussing weight. Most PwO (65%) preferred lifestyle changes over medications to lose weight. PwO and HCPs agreed that lack of exercise and unhealthy eating habits were the major barriers to weight loss. Our data highlights a discordance between the understanding of obesity as a disease and the actual behaviour and preferred approaches to manage it among PwO and HCPs. The study addresses a need to align these gaps to deliver optimal care for PwO., (© 2024 The Authors. Clinical Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

If some countries lead by example, standards may increasingly become normalized.

Weight stigma, defined as pervasive misconceptions and stereotypes associated with higher body weight, is both a social determinant of health and a human rights issue. It is imperative to consider how weight stigma may be impeding health promotion efforts on a global scale. The World Obesity Federation (WOF) convened a global working group of practitioners, researchers, policymakers, youth advocates, and individuals with lived experience of obesity to consider the ways that global obesity narratives may contribute to weight stigma. Specifically, the working group focused on how overall obesity narratives, food and physical activity narratives, and scientific and public-facing language may contribute to weight stigma. The impact of weight stigma across the lifespan was also considered. Taking a global perspective, nine recommendations resulted from this work for global health research and health promotion efforts that can help to reduce harmful obesity narratives, both inside and outside health contexts., (© 2023 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

Background: Type 2 diabetes (T2D), a major risk factor for cardiovascular disease and other adverse health conditions, is on the rise in Singapore. TRIPOD is a randomized controlled trial aimed to determine whether complementing usual care with an evidence-based diabetes management package (DMP) -comprising access to an evidence-based app, health coaching, pedometer, glucometer and weighing scale, with or without a financial rewards scheme (M-POWER rewards), can improve mean HbA 1c levels at months 6 and 12., Methods: The protocol was published in Trials, accessible via https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-019-3749-x 1 . This manuscript updates the protocol with changes to the study design due to challenges with recruitment and presents baseline characteristics. Key updates include changing the arm allocation ratio from 1:1:1 (Arm 1-Usual Care: Arm 2-DMP: Arm 3-DMP+M-POWER rewards) to 10:1:10, the sample size from 339 to 269, the intervention period from two to one year, and the primary hypothesis to focus solely on differences between Usual Care and DMP+M-POWER rewards. Recruitment for the study began on 19 October 2019 and ended on 4 June 2022., Results: The average age of participants was 55.0 (SD9.7) years old and 64.2% were male. The majority of participants (76.8%) were Chinese, 4.9% Malay and 18.3% Indian and of other ethnicities. 67.0% had a monthly household income of SGD$4000 or more. The mean baseline HbA 1c was 8.10% (SD 0.95) and the mean body mass index was 26.8 kg/m 2 (SD 5.3)., Discussion: The final participant completed month 12 follow-up data collection on 8 June 2023. All pre-planned analyses will be conducted and final results reported., Trial Registration: ClinicalTrials.gov NCT03800680 . Registered on 11 January 2019., (© 2023. The Author(s).)

Influenza is a highly contagious respiratory illness that commonly causes outbreaks among human communities. Details about the exact nature of the droplets produced by human respiratory activities such as breathing, and their potential to carry and transmit influenza A and B viruses is still not fully understood. The objective of our study was to characterize and quantify influenza viral shedding in exhaled aerosols from natural patient breath, and to determine their viral infectivity among participants in a university cohort in tropical Singapore. Using the Gesundheit-II exhaled breath sampling apparatus, samples of exhaled breath of two aerosol size fractions ("coarse" > 5 µm and "fine" ≤ 5 µm) were collected and analyzed from 31 study participants, i.e., 24 with influenza A (including H1N1 and H3N2 subtypes) and 7 with influenza B (including Victoria and Yamagata lineages). Influenza viral copy number was quantified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Infectivity of influenza virus in the fine particle fraction was determined by culturing in Madin-Darby canine kidney cells. Exhaled influenza virus RNA generation rates ranged from 9 to 1.67 × 10 5 and 10 to 1.24 × 10 4 influenza virus RNA copies per minute for the fine and coarse aerosol fractions, respectively. Compared to the coarse aerosol fractions, influenza A and B viruses were detected more frequently in the fine aerosol fractions that harbored 12-fold higher viral loads. Culturable virus was recovered from the fine aerosol fractions from 9 of the 31 subjects (29%). These findings constitute additional evidence to reiterate the important role of fine aerosols in influenza transmission and provide a baseline range of influenza virus RNA generation rates.

We conducted a prospective environmental surveillance study to investigate the air, surface, dust, and water contamination of a room occupied by a patient infected with mpox virus (MPXV) at various stages of the illness. The patient tested positive for MPXV from a throat swab and skin lesions. Environmental sampling was conducted in a negative pressure room with 12 unidirectional high efficiency particulate air filter (HEPA) air changes per hour and daily cleaning of the surfaces. A total of 179 environmental samples were collected on days 7, 8, 13, and 21 of illness. Among the days of sampling, air, surface, and dust contamination showed the highest contamination rates on day 7 and 8 of illness, with a gradual decline to the lowest contamination level by day 21. Viable MPXV was isolated from surfaces and dust samples and no viable virus was isolated from the air and water samples., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: As the world transitions to COVID-19 endemicity, studies focusing on aerosol shedding of highly transmissible SARS-CoV-2 variants of concern (VOCs) are vital for the calibration of infection control measures against VOCs that are likely to circulate seasonally. This follow-up Gesundheit-II aerosol sampling study aims to compare the aerosol shedding patterns of Omicron VOC samples with pre-Omicron variants analyzed in our previous study., Design: Coarse and fine aerosol samples from 47 patients infected with SARS-CoV-2 were collected during various respiratory activities (passive breathing, talking, and singing) and analyzed using reverse transcription-quantitative polymerase chain reaction and virus culture., Results: Compared with patients infected with pre-Omicron variants, comparable SARS-CoV-2 RNA copy numbers were detectable in aerosol samples of patients infected with Omicron despite being fully vaccinated. Patients infected with Omicron also showed a slight increase in viral aerosol shedding during breathing activities and were more likely to have persistent aerosol shedding beyond 7 days after disease onset., Conclusion: This follow-up study reaffirms the aerosol shedding properties of Omicron and should guide continued layering of public health interventions even in highly vaccinated populations., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: Postoperative outcomes vary considerably across bariatric patients and may be related to psychosocial factors. In this study, we examined whether a patient's family support predicts postsurgical weight loss and the remission of type 2 diabetes mellitus (T2DM)., Design: Retrospective cohort study in Singapore., Setting: Participants were recruited from a public hospital in Singapore., Participants: Between 2008 and 2018, 359 patients completed a presurgical questionnaire before undergoing gastric bypass or sleeve gastrectomy., Outcome Measures: As part of the questionnaire, patients described their family support in terms of structure (marital status, number of family members in the household) and function (marriage satisfaction, family emotional support, family practical support). Linear mixed-effects and Cox proportional-hazard models were used to examine whether these family support variables predicted percent total weight loss or T2DM remission up to 5 years postsurgery. T2DM remission was defined as glycated haemoglobin (HbA1c) <6.0% without medications., Results: Participants had a mean preoperative body mass index of 42.6±7.7 kg/m 2 and HbA1c (%) of 6.82±1.67. Marital satisfaction was found to be a significant predictor of postsurgical weight trajectories. Namely, patients who reported higher marital satisfaction were more likely to sustain weight loss than patients who reported lower marital satisfaction (β=0.92, SE=0.37, p=0.02). Family support did not significantly predict T2DM remission., Conclusions: Given the link between marital support and long-term weight outcomes, providers could consider asking patients about their spousal relationships during presurgical counselling., Trial Registration Number: NCT04303611., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Addressing weight stigma is essential to obesity management as it causes inequalities in healthcare and impacts the outcomes of health. This narrative review summarises systematic review findings about the presence of weight bias in healthcare professionals, and interventions to reduce weight bias or stigma in these professionals. Two databases (PubMed and Cumulative Index to Nursing and Allied Health Literature [CINAHL]) were searched. Seven eligible reviews were identified from 872 search results. Four reviews identified the presence of weight bias, and three investigated trials to reduce weight bias or stigma in healthcare professionals. The findings may help further research and the treatment, health and well-being of individuals with overweight or obesity in Singapore. Weight bias was prevalent among qualified and student healthcare professionals globally, and there is a lack of clear guidance for effective interventions to reduce it, particularly in Asia. Future research is essential to identify the issues and inform initiatives to reduce weight bias and stigma among healthcare professionals in Singapore., Competing Interests: None

Competing Interests: None

Obesity is a chronic disease in which the abnormal or excessive accumulation of body fat leads to impaired health and increased risk of mortality and chronic health complications. Prevalence of obesity is rising rapidly in South and Southeast Asia, with potentially serious consequences for local economies, healthcare systems, and quality of life. Our group of obesity specialists from Bangladesh, Brunei Darussalam, India, Indonesia, Malaysia, Philippines, Singapore, Sri Lanka, Thailand, and Viet Nam undertook to develop consensus recommendations for management and care of adults and children with obesity in South and Southeast Asia. To this end, we identified and researched 12 clinical questions related to obesity. These questions address the optimal approaches for identifying and staging obesity, treatment (lifestyle, behavioral, pharmacologic, and surgical options) and maintenance of reduced weight, as well as issues related to weight stigma and patient engagement in the clinical setting. We achieved consensus on 42 clinical recommendations that address these questions. An algorithm describing obesity care is presented, keyed to the various consensus recommendations., (© 2022 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

We evaluated diurnal trends of size-resolved indoor and outdoor fluorescent biological airborne particles (FBAPs) and their contributions to particulate matter (PM) within 0.5-20 μm. After a ten-week continuous sampling via two identical wideband integrated bioaerosol sensors, we found that both indoor and outdoor diurnal trends of PM were driven by its bioaerosol component. Outdoors, the median [interquartile range] FBAP mass concentration peaked at 8.2 [5.8-9.9] μg/m 3 around sunrise and showed a downtrend from 6:00 to 18:00 during the daytime and an uptrend during the night. The nighttime FBAP level was 1.8 [1.4-2.2] times higher than that during the daytime, and FBAPs accounted for 45 % and 56 % of PM during daytime and nighttime, respectively. Indoors, the rise in concentrations of FBAPs smaller than 1 μm coincided with the starting operation of the heating, ventilation, and air conditioning (HVAC) system at 6:00, and the concentration peaked at 8:00 and dropped to the daily average by noontime. This indicated that the starting operation of the HVAC system dislodged the overnight settled and accumulated fine bioaerosols into the indoor environment. For particles larger than 1 μm, the variation of mass concentration was driven by occupancy. Based on regression modeling, the contributions of indoor PM, non-FBAP, and FBAP sources to indoor mass concentrations were estimated to be 93 %, 67 %, and 97 % during the occupied period., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

SARS-CoV-2 has been recognized to be airborne transmissible. With the large number of reported positive cases in the community, home quarantine is recommended for the infectors who are not severely ill. However, the risks of household aerosol transmission associated with the quarantine room operating methods are under-explored. We used tracer gas technique to simulate the exhaled virus laden aerosols from a patient under home quarantine situation inside a residential testbed. The Sulphur hexafluoride (SF 6 ) concentration was measured both inside and outside the quarantine room under different operating settings including, air-conditioning and natural ventilation, presence of an exhaust fan, and the air movement generated by ceiling or pedestal fan. We calculated the outside-to-inside SF 6 concentration to indicate potential exposure of occupants in the same household. In-room concentration with air-conditioning was 4 times higher than in natural ventilation settings. Exhaust fan operation substantially reduced in-room SF 6 concentration and leakage rate in most of the ventilation scenarios, except for natural ventilation setting with ceiling fan. The exception is attributable to the different airflow patterns between ceiling fan (recirculates air vertically) and pedestal fan (moves air horizontally). These airflow variations also led to differences in SF 6 concentration at two sampling heights (0.1 m and 1.7 m) and SF 6 leakage rates when the quarantine room door was opened momentarily. Use of natural ventilation rather than air-conditioning, and operating exhaust fan when using air-conditioning are recommended to lower exposure risk for home quarantine. A more holistic experiment will be conducted to address the limitations reflected in this study., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Elsevier Ltd. All rights reserved.)

Objectives: To estimate the incremental per capita and aggregate direct and indirect costs of excess weight among older adults (aged 40-80) in Singapore., Design: Secondary data analysis of an existing cross-sectional survey SETTING: Residential districts in South-West Singapore PARTICIPANTS: 5848 older adults (aged 40-80) from Singapore's three dominant ethnic groups PRIMARY AND SECONDARY OUTCOME MEASURES: We used regression models to estimate per capita medical expenditures and absenteeism costs attributable to overweight and obesity based on WHO's body-mass index (BMI) classification. Per capita estimates were multiplied by prevalence to obtain aggregate costs., Results: The sample included 2467 Chinese, 2128 Indians and 1253 Malays. Indians and Malays are three to four times more likely to be obese (BMI≥30 kg/m 2 ) than Chinese. Among Chinese, compared with those who are normal weight, individuals who are overweight missed one additional workday per year more (p<0.05). Individuals in the obese category had S$720 per year greater medical expenditures (p<0.05) but missed workdays were not statistically different from those in the normal weight category. Among Indians, differences were not significant between normal and overweight categories. Indians in the obese category incurred an additional S$310 per year (p<0.10) more than those of normal weight. For Malays, no significant differences by BMI category were identified. Aggregate burden is estimated at S$261M (million) (95% CI: 57M to 465M) with 68% from medical expenditures. Chinese, Malays and Indians make up 79%, 12% and 9% of the population, respectively, but account for 76%, 19% and 4% of the costs of excess weight respectively., Conclusion: Excess weight imposes a substantial health and economic burden among older Singaporeans. Successful efforts to prevent and reduce obesity prevalence may generate both health and economic improvements., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) superspreading events suggest that aerosols play an important role in driving the coronavirus disease 2019 (COVID-19) pandemic. To better understand how airborne SARS-CoV-2 transmission occurs, we sought to determine viral loads within coarse (>5 μm) and fine (≤5 μm) respiratory aerosols produced when breathing, talking, and singing., Methods: Using a G-II exhaled breath collector, we measured viral RNA in coarse and fine respiratory aerosols emitted by COVID-19 patients during 30 minutes of breathing, 15 minutes of talking, and 15 minutes of singing., Results: Thirteen participants (59%) emitted detectable levels of SARS-CoV-2 RNA in respiratory aerosols, including 3 asymptomatic and 1 presymptomatic patient. Viral loads ranged from 63-5821 N gene copies per expiratory activity per participant, with high person-to-person variation. Patients earlier in illness were more likely to emit detectable RNA. Two participants, sampled on day 3 of illness, accounted for 52% of total viral load. Overall, 94% of SARS-CoV-2 RNA copies were emitted by talking and singing. Interestingly, 7 participants emitted more virus from talking than singing. Overall, fine aerosols constituted 85% of the viral load detected in our study. Virus cultures were negative., Conclusions: Fine aerosols produced by talking and singing contain more SARS-CoV-2 copies than coarse aerosols and may play a significant role in SARS-CoV-2 transmission. Exposure to fine aerosols, especially indoors, should be mitigated. Isolating viable SARS-CoV-2 from respiratory aerosol samples remains challenging; whether this can be more easily accomplished for emerging SARS-CoV-2 variants is an urgent enquiry necessitating larger-scale studies., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The utilization of physical dividers has been recommended as a practical approach to reducing the droplet and aerosol transmissions of the COVID-19 virus (SARS-CoV-2). This study conducted a series of experiments using video recording with a high-speed camera, particle image velocimetry (PIV) technique, and concentration measurements. The effectiveness of Perspex desk dividers impeding the transient transmission during coughing in five representative layouts was investigated. The results showed that the divider effectively protected the exposed person from an infector's cough seated in a face-to-face arrangement at a distance of 1.5 m. The aerosol concentration at the breathing zone was reduced by 99% compared to the layout without dividers. However, the reflection of aerosols from the dividers increased the exposure risk to the person seated beside the infector. Such risk was substantially reduced if the dividers were placed parallel between the infector and exposed person seated side-by-side. When the exposed person was staggered (face-to-face but displaced sideways laterally) to the infector with a 0.55-m lateral distance, the dividers reduced the potential exposure at the breathing zone by 60%. Considering the effectiveness in exposure reduction, the staggered configuration of desk dividers between the infector and exposed persons offers the best reduction to exposure., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: Obesity increases the risk of incident chronic kidney disease (CKD) and is one of the strongest risk factors for new-onset CKD even in the absence of metabolic risk factors. Weight loss has been shown to reduce renal hyperfiltration and proteinuria. Metabolic bariatric surgery (MBS) remains an effective treatment for obesity and its metabolic-related complications. However, literature on its impact on renal function remains limited., Materials and Methods: This was an observational retrospective study in a tertiary centre in Singapore. MBS cases performed at the centre between 2008 and 2019 were included. The primary outcome measures were estimated glomerular filtration rate (eGFR), calculated using the CKD epidemiology collaboration equation, and albuminuria (defined as urine albumin-creatinine ratio (uACR) > 3.5 mg/mmol) at baseline and 1-year post-MBS., Results: Five hundred fifty-seven patients were included. One-year post-MBS, median eGFR increased from 110.9 mL/min/1.73 m 2 (IQR 92.4 to 121.5) to 112.6 mL/min/1.73 m 2 (IQR 97.3 to 122.3), p < 0.001. Median uACR decreased from 1.00 mg/mmol (IQR 0.40 to 3.55) to 0.70 mg/mmol (IQR 0.40 to 1.80) 1-year post-MBS (p = 0.001). 12.9% of patients had improved CKD staging. The proportion of patients with albuminuria decreased from 24.8% at baseline to 1.89% 1-year post-MBS (p < 0.001). One-year post-MBS, the subgroup with reduced eGFR had significant increases in eGFR (p < 0.001), with a trend towards a reduction in uACR., Conclusions: MBS had a positive impact on renal function with modest but statistically significant improvement in eGFR and reduction in albuminuria at 1-year post-surgery. Longer-term data is required to investigate the durability of this impact., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Due to insufficient ventilation, public toilets present high risks for cross-infection. The study investigated 61 public toilets to identify the causes and locations of biological contaminated sources. Airborne and surface bacterial contamination, carbon dioxide concentration, and surface ammonia levels were measured. Both bacterial contamination and CO 2 are higher in non-ventilated toilets compared to their ventilated counterparts. Bacteria colony forming units (CFUs) in a public toilet with poor ventilation can reach 5 times the number of CFUs outside of the toilet. This suggests that non-ventilated public toilets present a higher risk of cross-infection. Areas near all kinds of sanitary equipment (toilet bowls, squat toilets and urinals) were highly contaminated, indicating that enhanced cleaning regimes are necessary. Further, lidless trash bins present a higher risk as contaminated matter within the trash bins is not inhibited from being released into the environment. Ventilation and cleaning need to be improved to mitigate the risk of cross-infection in public toilets., (© 2021. The Author(s).)

In a business as usual scenario, atmospheric carbon dioxide concentration (CO 2 ) could reach 950 parts per million (ppm) by 2100. Indoor CO 2 concentrations will rise consequently, given its dependence on atmospheric CO 2 levels. If buildings are ventilated following current standards in 2100, indoor CO 2 concentration could be over 1300 ppm, depending on specific ventilation codes. Such exposure to CO 2 could have physiological and psychological effects on building occupants. We conducted a randomized, within-subject study, examining the physiological effects on the respiratory functions of 15 persons. We examined three exposures, each 150 min long, with CO 2 of: 900 ppm (reference), 1450 ppm (decreased ventilation), and 1450 ppm (reference condition with added pure CO 2 ). We measured respiratory parameters with capnometry and forced vital capacity (FVC) tests. End-tidal CO 2 and respiration rates did not significantly differ across the three exposures. Parameters measured using FVC decreased significantly from the start to the end of exposure only at the reduced ventilation condition (p < 0.04, large effect size). Hence, poor ventilation likely affects respiratory parameters. This effect is probably not caused by increased CO 2 alone and rather by other pollutants-predominantly human bioeffluents in this work-whose concentrations increased as a result., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The combustion of fossil fuels is a significant source of particulate-bound black carbon (BC) in urban environments. The personal exposure (PE) of urban dwellers to BC and subsequent health impacts remain poorly understood due to a lack of observational data. In this study, we assessed and quantified the levels of PE to BC under two exposure scenarios (home-based and mobility-based exposure) in the city of Trivandrum in India. In the home-based scenario, the PE to BC was assessed in a naturally ventilated building over 24 h each day during the study period while in the mobility-based scenario, the PE to BC was monitored across diverse microenvironments (MEs) during the day using the same study protocol for consistency. Elevated BC concentrations were observed during the transport by motorcycle (26.23 ± 2.33 µg/m 3 ) and car (17.49 ± 2.37 µg/m 3 ). The BC concentrations observed in the MEs decreased in the following order: 16.58 ± 1.38 µg/m 3 (temple), 13.78 ± 2.07 µg/m 3 (restaurant), 11.44 ± 1.37 µg/m 3 (bus stop), and 8.27 ± 1.88 µg/m 3 (home); the standard deviations represent the temporal and spatial variations of BC concentrations. Overall, a relatively larger inhaled dose of BC in the range of 148.98-163.87 µg/day was observed for the mobility-based scenario compared to the home-based one (118.10-137.03 µg/day). This work highlights the importance of reducing PE to fossil fuel-related particulate emissions in cities for which BC is a good indicator. The study outcome could be used to formulate effective strategies to improve the urban air quality as well as public health.

The performance of a low-cost fan filter unit (FFU) in mitigating hazardous particulate matter (PM) levels in a naturally ventilated school classroom is presented. The FFU can be considered as a simplified mechanical ventilation and air-conditioning system without heating and cooling functions. The FFU improves indoor air quality through introduction of cleaned outdoor air to flush out internally generated heat and moisture and reducing infiltration by maintaining indoor pressurization. Indoor particle number concentrations were reduced between 85% and 95%. The particle removal performance (PRF FFU ) of the FFU is determined and incorporated into the augmented façade penetration factor (P aug ). A case-specific recursive dynamic mass balance model is used to characterize the infiltration factor (F INF ), deposition rate (K), and the penetration efficiency (P aug ) from continuously monitored indoor and outdoor mass concentration levels. Computed "P aug " (0.07, 0.09, and 0.13) and "F INF " (0.06, 0.08, and 0.11), respectively, for PM10, PM2.5, and PM1 suggest that exposure to PM was significantly reduced indoors. The effectiveness of the FFU for reduced "F INF " and "P aug " may be attributed to its superior filtration, dilution, and exfiltration mechanisms. In comparison with alternative PM mitigation solutions, the FFU is effective, affordable, and sustainable., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The adverse implications of obesity extend beyond physical health to include negative impact on quality of life (QoL), mood, and eating habits. While bariatric surgery provides successful weight loss and metabolic benefits, studies describe conflicting results on QoL and mood-related outcomes., Methods: Patients (n = 140) with class II/III obesity and T2DM were recruited from 2015 to 2019, and stratified based on medical or surgical treatment. Questionnaires including the Hospital Anxiety and Depression Scale, Euro QoL visual analogue scale (EQ-VAS), and Revised 21-item Three-Factor Eating Questionnaire (TFEQ-R21) were recorded at baseline, 6 months, and 12 months after treatment., Results: At baseline, the surgical group (n = 55) and medical group (n = 85) had no significant difference in questionnaire outcomes. At 6 and 12 months, EQ-VAS was higher in the surgical group (12 months surgical 82.00 ± 12.64, medical 72.81 ± 16.56, p = 0.001), with greater improvement from baseline. HADS-D scores at 12 months were lower in the surgical group (surgical 2.60 ± 2.88, medical 3.90 ± 3.58, p = 0.025). At 12 months, the surgical group also had better TFEQ-R21 scores, with higher cognitive restraint scores (surgical 19.09 ± 3.00, medical 16.69 ± 3.61, p < 0.001), and lower scores for uncontrolled eating (surgical 14.96 ± 3.87, medical 17.89 ± 5.34, p = 0.001)., Conclusion: In the treatment of patients with obesity and T2DM, bariatric surgery resulted in improved QoL outcomes at 12 months compared to medical therapy. This could be related to improvement in weight and metabolic outcomes, and altered gut-brain axis communication. This is the first prospective study assessing the impact of bariatric surgery on health-related QoL in Asia compared against a control group who received medical therapy.

Background: Family history has traditionally been an essential part of clinical care to assess health risks. However, declining sequencing costs have precipitated a shift towards genomics-first approaches in population screening programs rendering the value of family history unknown. We evaluated the utility of incorporating family history information for genomic sequencing selection., Methods: To ascertain the relationship between family histories on such population-level initiatives, we analysed whole genome sequences of 1750 research participants with no known pre-existing conditions, of which half received comprehensive family history assessment of up to four generations, focusing on 95 cancer genes., Results: Amongst the 1750 participants, 866 (49.5%) had high-quality standardised family history available. Within this group, 73 (8.4%) participants had an increased family history risk of cancer (increased FH risk cohort) and 1 in 7 participants (n = 10/73) carried a clinically actionable variant inferring a sixfold increase compared with 1 in 47 participants (n = 17/793) assessed at average family history cancer risk (average FH risk cohort) (p = 0.00001) and a sevenfold increase compared to 1 in 52 participants (n = 17/884) where family history was not available (FH not available cohort) (p = 0.00001). The enrichment was further pronounced (up to 18-fold) when assessing only the 25 cancer genes in the American College of Medical Genetics (ACMG) Secondary Findings (SF) genes. Furthermore, 63 (7.3%) participants had an increased family history cancer risk in the absence of an apparent clinically actionable variant., Conclusions: These findings demonstrate that the collection and analysis of comprehensive family history and genomic data are complementary and in combination can prioritise individuals for genomic analysis. Thus, family history remains a critical component of health risk assessment, providing important actionable data when implementing genomics screening programs., Trial Registration: ClinicalTrials.gov NCT02791152 . Retrospectively registered on May 31, 2016.

Singapore is a tropical country with a high density of day-care facilities whose indoor environments may be adversely affected by outdoor fine particle (PM 2.5 ) air pollution. To reduce this problem requires effective, evidence-based exposure-reduction strategies. Little information is available on the penetration of outdoor PM 2.5 into day-care environments. Our study attempted to address the following objectives: to measure indoor infiltration factor (F inf ) of PM 2.5 from outdoor PM 2.5 and to determine the building parameters that modify the indoor PM 2.5 . We collected indoor/outdoor 1-min PM 2.5 from 50 day-care classrooms. We noted mean F inf  ± SD of 0.65 ± 0.22 in day-care rooms which are naturally ventilated and lower F inf  ± SD values of 0.47 ± 0.18 for those that are air-conditioned: values which are lower than those reported in Singapore residences. The air exchange rates were higher in naturally ventilated rooms (1.47 vs 0.86 h -1 ). However, fine particle deposition rates were lower for naturally ventilated rooms (0.67 ± 0.43 h -1 ) compared with air-conditioned ones (1.03 ± 0.55 h -1 ) presumably due to composite rates linked to the filters within the split unit air-conditioners, higher recirculation rates, and interior surfaces in the latter. Our findings indicate that children remaining indoor in daycares where air-conditioning is used can reduce their PM 2.5 exposures during outdoor pollution episodes., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study evaluated the interrelations between indoor and outdoor bioaerosols in a bedroom under a living condition. Two wideband integrated bioaerosol sensors were utilized to measure indoor and outdoor particulate matter (PM) and fluorescent biological airborne particles (FBAPs), which were within a size range of 0.5-20 μm. Throughout this one-month case study, the median proportion of FBAPs in PM by number was 19% (5%; the interquartile range, hereafter) and 17% (3%) for indoors and outdoors, respectively, and those by mass were 78% (12%) and 55% (9%). According to the size-resolved data, FBAPs dominated above 2 and 3.5 μm indoors and outdoors, respectively. Comparing indoor upon outdoor ratios among occupancy and window conditions, the indoor FBAPs larger than 3.16 μm were dominated by indoor sources, while non-FBAPs were mainly from outdoors. The occupant dominated the indoor source of both FBAPs and non-FBAPs. Under awake and asleep, count- and mass-based mean emission rates were 45.9 and 18.7 × 10 6 #/h and 5.02 and 2.83 mg/h, respectively. Based on indoor activities and local outdoor air quality in Singapore, this study recommended opening the window when awake and closing it during sleep to lower indoor bioaerosol exposure., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The effect of preoperative weight loss via very low caloric diet (VLCD) on long-term weight loss post-bariatric surgery (BS) is conflicting. We analysed its impact on weight loss and other outcomes post-BS., Methods: Patients (n = 306) who underwent sleeve gastrectomy or gastric bypass from 2008 to 2018 were studied. VLCD was prescribed for 14 days preoperatively. Patients were followed up for 5 years. Postoperative weight loss was compared in patients with preoperative weight gain or weight loss < 5% (WL < 5%), and weight loss ≥ 5% (WL ≥ 5%). Preoperative WL compared weight before and after VLCD; postoperative WL compared post-VLCD weight and follow-up weight. Total weight loss (TWL) encompassed pre- and postoperative WL., Results: WL was < 5% in 87.3% and ≥ 5% in 12.7%. There was no significant difference in complication rate, duration of surgery or length of stay, regardless of surgical type. Patients with WL < 5% lost more weight postoperatively compared with WL ≥ 5% for up to 60 months (%postoperative WL at 1 month: WL < 5% = 13.7%, WL ≥ 5% = 10%, p = <0.001; 60 months: WL < 5% = 30.6%, WL ≥ 5% = 23.9%, p = 0.041). However, when TWL and percentage of excess body mass index loss (%EBMIL) were measured, there was no difference beyond 6 months. A predictive multivariable model for 1-year %EBMIL was formed. Significant variables included pre-VLCD BMI and preoperative WL, and the relationship between the two., Conclusion: Preoperative WL via VLCD was associated with reduced postoperative WL after BS, with no significant effect on complications, long-term TWL or %EBMIL. This challenges the notion that preoperative WL via VLCD should be mandated for better postoperative outcomes.

Importance: Few studies have described the longitudinal trajectories of serum levels of micronutrients whose deficiencies are associated with serious sequelae following bariatric procedures, such as anemia, osteoporotic fractures, and neuropathies. Furthermore, previous studies comparing laparoscopic sleeve gastrectomy (LSG) vs Roux-en-Y gastric bypass (LRYGB) or one-anastomosis gastric bypass (OAGB) procedures may have been limited by selection and confounding biases., Objective: To appraise the spectrum and temporal course of micronutrient deficiencies associated with bone metabolism and erythropoiesis after LSG vs OAGB or LRYGB procedures, using the propensity score as a balancing score., Design, Setting, and Participants: This prospective, longitudinal comparative effectiveness study was conducted at a high-volume bariatric unit in Singapore from September 1, 2008, to November 30, 2017, with a cutoff date for analysis of September 2018. Patients who underwent adjustable gastric banding, biliopancreatic diversion procedures, and intragastric balloon procedures were excluded. All other patients who underwent bariatric procedures were included. Data were analyzed from September 23 to 30, 2018., Main Outcomes and Measures: Serial assessment of 13 biochemical parameters at 12 time points for up to 5 years after bariatric procedure. Inverse probability-of-treatment weights were used to obtain estimates of the mean associations of variables assessed with the bariatric surgical interventions. Longitudinal trajectories were analyzed using mixed-effects generalized linear models to apportion the temporal variation of serum micronutrients into fixed-effects and random-effects components., Results: A total of 688 patients were included in this study, of whom 499 underwent LSG (mean [SD] age, 41.5 [11.3] years; 318 [63.7%] women) and 189 underwent OAGB or LRYGB (mean [SD] age, 48.6 [9.4] years; 112 [59.3%] women). There were no differences during follow-up among patients who underwent LSG vs those who underwent OAGB or LRYGB in intact parathyroid hormone levels (mean difference, 7.05 [95% CI, -28.67 to 42.77] pg/mL; P = .70), serum 25-hydroxyvitamin D levels (mean difference, -0.72 [95% CI, -1.56 to 0.12] ng/mL; P = .09), or phosphate levels (mean difference, 0.006 [95% CI, -0.052 to 0.064] mg/dL; P = .83). Hemoglobin levels were a mean 0.63 (95% CI, 0.41 to 0.85) g/dL higher among patients who underwent LSG compared with those who underwent OAGB or LRYGB (P < .001), despite no differences in iron concentration levels (mean difference, 1.50 [95% CI, -1.39 to 4.39] µg/dL; P = .31), total iron-binding capacity (mean difference, 4.36 [95% CI, -5.25 to 13.98] µg/dL; P = .37), or ferritin levels (mean difference, 3.0 [95% CI, -13.0 to 18.9] ng/mL; P = .71). Compared with patients who underwent LSG procedures, patients who underwent OAGB or LRYGB had higher folate levels (mean difference, 2.376 [95% CI, 1.716 to 3.036] ng/mL; P < .001) but lower serum magnesium levels (mean difference, -0.25 [95% CI, -0.35 to -0.16] mg/dL; P < .001) and zinc levels (mean difference, -7.58 [95% CI, -9.92 to -5.24] µg/dL; P < .001)., Conclusions and Relevance: These findings suggest that LSG vs OAGB or LRYGB procedures have differential associations with various micronutrient and metabolic parameters. These differences should be recognized in guidelines for postbariatric nutritional surveillance and prevention.

To date, exposure studies linking dust-mite allergens with asthma and allergic morbidities have typically relied on sampling from representative locations in the home for exposure assessment. We determine the effects of differing microenvironments allergen exposures on asthma and asthma severity among 25 case and 31 control preschool children in Singapore. Blo t 5 allergen levels in various niches from the children's home and day-care microenvironments as well as their Blo t 5 time-weighted concentrations were determined. Eosinophilic cationic protein (ECP) levels from the children's saliva as markers for airway inflammation were obtained. Salivary ECP levels were higher in children with asthma than those without and the strength of association increased with higher salivary ECP levels. Although there was no relationship between time-weighted Blo t 5 concentrations with salivary ECP levels among the controls, a positive statistically significant relationship was noted among cases, demonstrating the effects of cumulative exposure on asthma severity. Avoidance measures to reduce Blo t 5 allergen exposure should include all microenvironments that asthmatic children are exposed throughout the day., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Data on attitudes and perceptions towards obesity are lacking in Asia. Participants who attended an obesity public forum were surveyed concerning obesity and its treatment options. Although obesity is generally accepted as a disease with biological underpinnings such as hormonal imbalances and slow metabolic rate, it is also regarded as an issue of personal responsibility. 65.1% believed that weight-loss medications are dangerous. 20.6% thought that pharmacotherapy is effective for weight loss, whereas 41.1% were unsure. Most believed that bariatric surgery could improve health (81.9%) and diabetes control (74.0%) although 64.1% were unsure of its risks., (Copyright © 2019 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Obesity plays a pivotal role in the pathogenesis of obstructive sleep apnea (OSA) and as an exacerbating factor of OSA. Given the interlinking relationship of obesity and OSA, treatment of obesity is fundamental in the management of OSA. Weight loss of 7% to 11% significantly improves OSA with remission seen with greater weight loss. Weight loss also ameliorates the constellation of other obesity-related metabolic conditions, reducing the overall cardiovascular risk in an obese person with OSA. This article discusses specific weight loss interventions effective in improving OSA, including lifestyle interventions with dietary modification and physical activity, pharmacotherapy, and bariatric surgery., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Micronutrient deficiencies are highly prevalent in patients seeking metabolic-bariatric surgery (MBS), although literature remains scant in Asia. In this study, we assess the prevalence of nutritional deficiencies in patients with clinically severe obesity in Singapore and examine factors associated with the deficiencies., Methods: This is a prospective, observational study of 577 consecutive patients scheduled to undergo MBS. Nutritional profile including renal panel, calcium, phosphate, intact parathyroid hormone (iPTH), 25-hydroxyvitamin D (25(OH)D), vitamin B12, folate, ferritin, iron studies, hemoglobin, albumin, and alkaline phosphatase were analyzed., Results: Mean age was 40.6 ± 10.3 years, 61.2% female, and mean BMI 42.4 ± 8.4 kg/m 2 . 92.9% had suboptimal vitamin D levels; of which 25.6% had vitamin D insufficiency (25(OH)D < 30 mcg/L), 57.5% had vitamin D deficiency (25(OH)D < 20 mcg/L), and 9.8% had severe vitamin D deficiency (25(OH)D < 10 mcg/L). Younger age, female gender, and higher BMI were independent factors associated with lower 25(OH)D. There was an inverse relationship between iPTH and 25(OH)D, with an inflection point at 25(OH)D of approximately 20 mcg/L. Folate deficiency was present in 31% and vitamin B12 deficiency in 9.5% of the cohort. Serum ferritin levels were low in 29.3%. 25(OH)D, ferritin, serum iron, and albumin were also significantly higher in Chinese compared to Malay and Indian patients., Conclusion: Vitamin D deficiency was the most common micronutrient deficiency observed in this multi-ethnic Asian cohort presenting for MBS. Ethnic differences in nutritional status were observed.