Can ship travel contain COVID-19 outbreak after re-opening: a Bayesian meta-analysis.

Large gatherings of people on cruise ships and warships are often at high risk of COVID-19 infections. To assess the transmissibility of SARS-CoV-2 on warships and cruise ships and to quantify the effectiveness of the containment measures, the transmission coefficient (ß), basic reproductive number (R0), and time to deploy containment measures were estimated by the Bayesian Susceptible-Exposed-Infected-Recovered model. A meta-analysis was conducted to predict vaccine protection with or without non-pharmaceutical interventions (NPIs). The analysis showed that implementing NPIs during voyages could reduce the transmission coefficients of SARS-CoV-2 by 50%. Two weeks into the voyage of a cruise that begins with 1 infected passenger out of a total of 3,711 passengers, we estimate there would be 45 (95% CI:25-71), 33 (95% CI:20-52), 18 (95% CI:11-26), 9 (95% CI:6-12), 4 (95% CI:3-5), and 2 (95% CI:2-2) final cases under 0%, 10%, 30%, 50%, 70%, and 90% vaccine protection, respectively, without NPIs. The timeliness of strict NPIs along with implementing strict quarantine and isolation measures is imperative to contain COVID-19 cases in cruise ships. The spread of COVID-19 on ships was predicted to be limited in scenarios corresponding to at least 70% protection from prior vaccination, across all passengers and crew.

Effect of indoor air quality on the association of long-term exposure to low-level air pollutants with cognition in older adults.

BACKGROUND: How indoor air quality affects the temporal associations of long-term exposure to low-level air pollutants with cognition remains unclear. METHODS: This cohort study (2011-2019) included 517 non-demented older adults at baseline with four repeated cognitive assessments. The time-varying exposure to PM2.5, PM10, NO2, SO2, CO, and O3 was estimated for each participant from 1994 to 2019. Indoor air quality was determined by ventilation status and daily indoor time. Generalized linear mixed models were used to analyze the association of air pollutants, indoor air quality, and cognition adjusting for important covariates. RESULTS: Over time, per 2.97 µg/m3 (i.e., an interquartile range) increment of PM2.5 was associated with the poor performance of memory (Z score of a cognitive test, ߈:-0.14), attention (߈:-0.13), and executive function (߈:-0.20). Similarly, per 2.05 µg/m3 increase in PM2.5-10 was associated with poor global cognition [adjusted odds ratio (aOR): 1.48, ߈:-0.28], attention (߈:-0.07), and verbal fluency (߈:-0.09); per 4.94 µg/m3 increase in PM10 was associated with poor global cognition (aOR: 1.78; ߈:-0.37). In contrast, per 2.74 ppb increase in O3 was associated with better global cognition (߈:0.36 to 0.47). These associations became more evident in participants with poor ventilation or short daily indoor time (<12.5 h/day). For global cognition, the exposure to a 10-µg/m3 increment in PM2.5, PM2.5-10, and PM10 corresponded to 1.4, 5.8, and 2.8 years of aging, respectively. CONCLUSION: This study demonstrated how indoor air quality in areas using clean fuels differentially affected the associations of long-term exposure to low-level air pollutants with cognition. Tightening air quality standards may help prevent dementia.

Recommendations for ventilation of remodeled negative-pressure isolation wards for COVID-19 patients: A comparison of international guidelines.

This mini-review provides the practice guideline recommendations for ventilation of remodeled negative-pressure isolation wards for COVID-19 Patients. Remodeled "quasi-negative-pressure" isolation wards had been proved a feasible, inexpensive, safe, and effective measure to contain nosocomial outbreaks. We should first determine the minimum required ventilation volume of an isolation ward based on the severity of COVID-19 patients. Mechanical ventilation remains the mainstay for achieving the requirement, while the assistance of recirculation is also helpful. Beyond adequate ventilation volume, the "clean to less-clean" directional airflow remains the golden rule for the solution of indoor ventilation. The virus-laden exhaust should be treated with HEPA/UV device or be kept away from living organisms, buildings, and air inlets.

Association between urinary manganese and pulmonary function in young adults: A cross-sectional design with a longitudinal cohort validation.

BACKGROUND: The impact of heavy metals on pulmonary function among young adults has been scarcely studied, especially by a longitudinal cohort study. METHODS: We prospectively enrolled 974 young adults (aged 20-45 years) during 2017-2019 and measured pulmonary function and urinary heavy metals, including manganese, copper, chromium, iron, nickel, zinc, cadmium, and lead. Among them, 461 participants had examination of the same urinary heavy metals during 2006-2008, which could be used as a cohort for long-term effect of urinary metals on pulmonary function. RESULTS: In the 974 enrolled participants, urinary heavy metals were within normal range. The urinary manganese level was the only significant factor for the observed/predicted ratios of forced vital capacity (FVC %)(ß coefficient: -1.217, p = 0.030), forced expiratory volume in one second (FEV1%)(ß: -1.664, p < 0.001), and FEV1/FVC% of predicted (ß: -0.598, p = 0.047) in multivariable linear regression under cross sectional design. In cohort analysis, the urinary manganese level was also negatively associated with the FEV1% (ß: -1.920, p = 0.021). There was no significance between other urinary heavy metals and pulmonary function for all participants. The urinary manganese significantly negatively correlated with FVC%, FEV1% and FEV1/FVC% in female subgroup whereas copper and iron were significantly negatively correlated with FVC% in male subgroup. CONCLUSIONS: Among urinary heavy metals, urinary manganese level was associated with pulmonary function negatively, even the level was within normal range. In addition, women might be more susceptible to manganese. There is emergent need to conduct further investigation to confirm the respiratory hazardous effects of manganese.

Synthesis of Antioxidative Conductive Copper Inks with Superior Adhesion.

Conductive films have attracted much attention in the printed electronics industry. To date, expensive conductive silver inks have been utilized widely in these conductive films, which ultimately increase the cost. Hence the alternative low-cost copper inks will be of great interest in the future. This paper will present how to synthesize antioxidative conductive copper inks with superior adhesion to FR4 substrates. The antioxidative conductive copper inks were prepared by dispersing the antioxidative copper nanoparticles in diethylene glycol with the bisphenol-F type BEF170 epoxy resin as a binder and the Methyl-5-norbornene-2,3-dicarboxylic anhydride (NMA) as a curing agent, then were coated on FR4 substrates to form the copper films, followed by sintering at 250 °C in nitrogen atmosphere for 20 minutes. We found that the formation of three-dimensional structure between BFE170 binder and curing agent NMA don't affect the conductivities of copper films, and meanwhile can enhance the adhesion strength on FR4 substrates. The lowest resistivity of 158 µΩ · cm determined by using the four-point probe method and the highest adhesion of no peeling after the 10 times peel-off test with 3 M Scotch 600 tape were achieved with the copper ink composed of 1 wt% of BEF170 epoxy resin binder mixed with curing agent NMA in an equivalent ratio of 1:1.

Installation of a flow control device in an inclined air-curtain fume hood to control wake-induced exposure.

An inclined plate for flow control was installed at the lower edge of the sash of an inclined air-curtain fume hood to reduce the effects of the wake around a worker standing in front of the fume hood. Flow inside the fume hood is controlled by the inclined air-curtain and deflection plates, thereby forming a quad-vortex flow structure. Controlling the face velocity of the fume hood resulted in convex, straight, concave, and attachment flow profiles in the inclined air-curtain. We used the flow visualization and conducted a tracer gas test with a mannequin to determine the performance of two sash geometries, namely, the half-cylinder and inclined plate designs. When the half-cylinder design was used, the tracer gas test registered a high leakage concentration at Vf ≦ 57.1 fpm or less. This concentration occurred at the top of the sash opening, which was close to the breathing zone of the mannequin placed in front of the fume hood. When the inclined plate design was used, the containment was good, with concentrations of 0.002-0.004 ppm, at Vf ≦ 63.0 fpm. Results indicate that an inclined plate effectively reduces the leakage concentration induced by recirculation flow structures that form in the wake of a worker standing in front of an inclined air-curtain fume hood.

Effects of boundary-layer separation controllers on a desktop fume hood.

A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s).

A double-negative feedback loop between Wnt-ß-catenin signaling and HNF4α regulates epithelial-mesenchymal transition in hepatocellular carcinoma.

Wnt-ß-catenin signaling participates in the epithelial-mesenchymal transition (EMT) in a variety of cancers; however, its involvement in hepatocellular carcinoma (HCC) and downstream molecular events is largely undefined. HNF4α is the most prominent and specific factor maintaining the differentiation of hepatic lineage cells and a potential EMT regulator in HCC cells. However, the molecular mechanisms by which HNF4α maintains the differentiated liver epithelium and inhibits EMT have not been completely defined. In this study, we systematically explored the relationship between Wnt-ß-catenin signaling and HNF4α in the EMT process of HCC cells. Our results indicated that HNF4α expression was negatively regulated during Wnt-ß-catenin signaling-induced EMT through Snail and Slug in HCC cells. In contrast, HNF4α was found to directly associate with TCF4 to compete with ß-catenin but facilitate transcription co-repressor activities, thus inhibiting expression of EMT-related Wnt-ß-catenin targets. Moreover, HNF4α may control the switch between the transcriptional and adhesion functions of ß-catenin. Overexpression of HNF4α was found to completely compromise the Wnt-ß-catenin-signaling-induced EMT phenotype. Finally, we determined the regulation pattern between Wnt-ß-catenin signaling and HNF4α in rat tumor models. Our studies have identified a double-negative feedback mechanism controlling Wnt-ß-catenin signaling and HNF4α expression in vitro and in vivo, which sheds new light on the regulation of EMT in HCC. The modulation of these molecular processes may be a method of inhibiting HCC invasion by blocking Wnt-ß-catenin signaling or restoring HNF4α expression to prevent EMT.

Development and characterization of an inclined air-curtain (IAC) fume hood.

An inclined air-curtain (IAC) fume hood was developed and characterized using the laser-assisted smoke flow visualization technique and tracer-gas (sulphur hexafluoride) concentration detection method. The IAC fume hood features four innovative design elements: (i) an elongated suction slot installed at the hood roof with an offset towards the rear wall, (ii) an elongated up-blowing planar jet issued from the work surface near the hood inlet, (iii) two deflection plates installed at the left and right side walls, and (iv) a boundary-layer separation controller installed at the sash bottom. Baffles employed in conventional hoods were not used. The suction slot and the up-blowing planar jet formed a rearward-inclined push-pull air curtain. The deflection plates worked with the inclined air curtain to induce four rearward-inclined counter-rotating 'tornados.' The fumes generated in the hood were isolated behind the rearward-inclined air curtain, entrained by the low pressure within the vortical flows, moved up spirally, and finally exhausted through the suction slot. The risk of containment leakage due to the large recirculation vortex that usually exists behind the sash of conventional hoods was reduced by the boundary-layer separation controller. The results of the tracer-gas concentration detection method based on the EN-14175 method showed that the flow field created by the geometric configurations of the IAC hood presented characteristics of low leakage and high resistance to dynamic disturbances at low face velocities. The leakage levels measured by the static, sash movement, and walk-by tests were negligible at a face velocity of 0.26 m s(-1).

Flow characteristics and spillage mechanisms of an inclined quad-vortex range hood subject to influence from draft.

The flow and spillage characteristics of an inclined quad-vortex (IQV) range hood subject to the influence of drafts from various directions were studied. The laser-assisted smoke flow visualization technique was used to reveal the flow characteristics, and the tracer-gas (sulfur hexafluoride) concentration detection method was used to indicate the quantitative values of the capture efficiency of the hood. It was found that the leakage mechanisms of the IQV range hood are closely related to the flow characteristics. A critical draft velocity of about 0.5 m/s and a critical face velocity of about 0.25 m/s for the IQV range hood were found. When the IQV range hood was influenced by a draft with a velocity larger than the critical draft velocity, the spillage of pollutants became significant and the pollutant spillage rate increased with increasing draft velocity. At draft velocities less than or equal to the critical value, no containment leakages induced by the turbulence diffusion, reverse flow, or boundary-layer separation were observed, and the capture efficiency was about 100%. The IQV range hood exhibited a high ability to resist the influences of lateral and frontal drafts. The capture efficiency of the IQV range hood operated at the suction flow rate 5 to 9 m(3)/min is higher than that of the conventional range hood operated at 11 to 15 m(3)/min.

Improving flow patterns and spillage characteristics of a box-type commercial kitchen hood.

A conventional box-type commercial kitchen hood and its improved version (termed the "IQV commercial kitchen hood") were studied using the laser-assisted smoke flow visualization technique and tracer-gas (sulfur hexafluoride) detection methods. The laser-assisted smoke flow visualization technique qualitatively revealed the flow field of the hood and the areas apt for leakages of hood containment. The tracer-gas concentration detection method measured the quantitative leakage levels of the hood containment. The oil mists that were generated in the conventional box-type commercial kitchen hood leaked significantly into the environment from the areas near the front edges of ceiling and side walls. Around these areas, the boundary-layer separation occurred, inducing highly unsteady and turbulent recirculating flow, and leading to spillages of hood containment due to inappropriate aerodynamic design at the front edges of the ceiling and side walls. The tracer-gas concentration measurements on the conventional box-type commercial kitchen hood showed that the sulfur hexafluoride concentrations detected at the hood face attained very large values on an order of magnitude about 10(3)-10(4) ppb. By combining the backward-offset narrow suction slot, deflection plates, and quarter-circular arcs at the hood entrance, the IQV commercial kitchen hood presented a flow field containing four backward-inclined cyclone flow structures. The oil mists generated by cooking were coherently confined in these upward-rising cyclone flow structures and finally exhausted through the narrow suction slot. The tracer-gas concentration measurements on the IQV commercial kitchen hood showed that the order of magnitude of the sulfur hexafluoride concentrations detected at the hood face is negligibly small--only about 10(0) ppb across the whole hood face.

Flow and containment characteristics of a sash-less, variable-height inclined air-curtain fume hood.

To increase containment efficiency and reduce energy consumption, a sash-less, variable-height inclined air-curtain fume hood (sIAC hood) was developed and tested by a laser-assisted flow visualization technique and tracer-gas detection method. This novel design requires neither sash nor baffle. The sIAC hood employed the inclined push-pull air-curtain technique and two deflection plates installed on the side walls of the hood to induce a tetra-vortex flow structure. The results of flow visualization showed that the slot for suction flow, offset from the slot for the up-blowing jet, caused the air curtain to incline towards the rear wall, thus enhancing the robustness of the tetra-vortex flow structure. Such a flow structure could reduce the influence of draught and human walk-by across the hood face. The containment around the central area of the hood was isolated by the inclined push-pull air curtain. The pollutants carried by the reverse flow induced by the flow separation were guided by the deflection plates from the side walls towards the rear, thus contributing to the formation of the tetra-vortex flow structure. The up/down movable ceiling positioned the suction slot close to the device's pollutant emission opening, but left room (less than 50 cm) for unrestricted hand movement. Testing was carried out based on the methodology described in EN14175. The results of a static test showed that small face velocities of 0.25 and 0.16 m s(-1) were enough to obtain nearly null leakage levels for low and tall pollutant sources. The results of a traversing plate test showed that the face velocity, 0.32 m s(-1), would cause negligibly small leakage levels. The sIAC hood could obtain significantly higher containment efficiency than a conventional hood by operating at a face velocity significantly lower than that of conventional hoods.

Development and characterization of an inclined quad-vortex range hood.

In order to increase containment efficiency and reduce energy consumption, an inclined quad-vortex range hood (IQV range hood) was developed and tested by experimental methods. The flow structure was observed by a laser-assisted flow visualization technique and laser Doppler velocimetry (LDV). Leakage characteristics were measured by the tracer gas (sulfur hexafluoride) detection method. By arranging a narrow suction slot on the bottom face of the hood and two side plates hanging under lateral faces of the hood, a flow field featuring four backwards-inclined vortical flow structures was formed at suction velocities of larger than about 10 m s(-1) (suction flow rate 7.2 m(3) min(-1)). Oil mists were coherently contained in the vortical flow structures without observable dispersion out of the vortices; they rose up spirally with inclination towards the rear wall and were inducted into the suction slot. The backwards inclination of the oil-mist-containing vortical flow structures, caused by the backwards offset arrangement of the suction slot and the Coanda effect, benefited from the reduction in pollutant leakage induced by the influence of a mannequin's presence. Experimental results using the tracer gas concentration detection method showed a close correlation with the results from the flow visualization and LDV measurements. Under both occupied and unoccupied conditions, in which the mannequin was either present or not present, the IQV range hood provided low SF6 leakage concentration levels.

Flow and leakage characteristics of a sashless inclined air-curtain (sIAC) fume hood containing tall pollutant-generation tanks.

In many fume hood applications, pollutant-generation devices are tall. Human operators of a fume hood must stand close to the front of the hood and lift up their hands to reach the top opening of the tall tank. In this situation, it is inconvenient to access the conventional hood because the sash acts as a barrier. Also, the bluff-body wake in front of the operator's chest causes a problem. By using laser-assisted smoke flow visualization and tracer-gas test methods, the present study examines a sashless inclined air-curtain (sIAC) fume hood for tall pollutant-generation tanks, with a mannequin standing in front of the hood face. The configuration of the sIAC fume hood, which had the important element of a backward-inclined push-pull air curtain, was different from conventional configurations. Depending on suction velocity, the backward-inclined air curtain had three characteristic modes: straight, concave, and attachment. A large recirculation bubble covering the area--from the hood ceiling to the work surface--was formed behind the inclined air curtain in the straight and concave modes. In the attachment mode, the inclined air curtain was attached to the rear wall of the hood, about 50 cm from the hood ceiling, and bifurcated into up and down streams. Releasing the pollutants at an altitude above where the inclined air curtain was attached caused the suction slot to directly draw up the pollutants. Releasing pollutants in the rear recirculation bubble created a risk of pollutants' leaking from the hood face. The tracer-gas (SF6) test results showed that operating the sIAC hood in the attachment mode, with the pollutants being released high above the critical altitude, could guarantee almost no leakage, even though a mannequin was standing in front of the sashless hood face.

Assessing Indoor Climate Control in a Water-Pad System for Small-Scale Agriculture in Taiwan: A CFD Study on Fan Modes.

Heat stress poses a significant challenge to egg production in layer hens. High temperatures can disrupt the physiological functions of these birds, leading to reduced egg production and lower egg quality. This study evaluated the microclimate of laying hen houses using different management systems to determine the impact of heat stress on productivity and hen health. The results showed that the ALPS system, which manages the hen feeding environment, effectively improved productivity and decreased the daily death rate. In the traditional layer house, the daily death rate decreased by 0.045%, ranging from 0.086% to 0.041%, while the daily production rate increased by 3.51%, ranging from 69.73% to 73.24%. On the other hand, in a water-pad layer house, the daily death rate decreased by 0.033%, ranging from 0.082% to 0.049%, while the daily production rate increased by 21.3%, ranging from 70.8% to 92.1%. The simplified hen model helped design the indoor microclimate of commercial layer houses. The average difference in the model was about 4.4%. The study also demonstrated that fan models lowered the house's average temperature and reduced the impact of heat stress on hen health and egg production. Findings indicate the need to control the humidity of inlet air to regulate temperature and humidity, and suggest that Model 3 is an energy-saving and intelligent solution for small-scale agriculture. The humidity of the inlet air affects the temperature experienced by the hens. The THI drops to the alert zone (70-75) when humidity is below 70%. In subtropical regions, we consider it necessary to control the humidity of the inlet air.

Flow characteristics and spillage mechanisms of wall-mounted and jet-isolated range hoods subject to influence from cross draft.

The effects of draft on the flow and spillage characteristics of wall-mounted and jet-isolated range hoods were investigated. A specially designed draft generator that could supply low-swirl air current was used to provide "cross draft" from three directions, lateral (θ = 0(o)), oblique (θ = 45(o)), and front (θ = 90(o)), with respect to the center point of the range hoods. Flow characteristics of oil mist were inspected through visualization of smoke flows with light scattering (laser light sheet-assisted visualization of smoke flow). The leakage mechanisms, which were closely related to the flow features, were studied by examining both movies and still pictures showing smoke-flow evolution. The sulfur hexafluoride tracer gas concentration detection method was employed to measure the capture indices. The results showed that the lateral draft pushed the pollutants generated under the hood in the opposite direction and induced serious spillage. The oblique draft pushed the pollutants toward both the rear wall and opposite side and induced more serious spillage than did the lateral draft. The frontal draft forced the pollutants to bifurcate into streams moving toward the left and the right, and induced the most serious pollutant spillage among the three tested drafts. Pollutant spillage became critically significant as the cross draft velocity was increased to greater than 0.2 m/sec. Spillage of pollutants increased as the velocity of the cross draft was increased. Increasing the suction flow rate of the range hood may increase resistance to the draft, but the benefits were limited at draft velocities greater than 0.2 m/sec. Both range hoods had a similarly low capture index under the influence of the lateral draft. For the oblique and frontal drafts, the jet-isolated range hood demonstrated a higher capture index than did the wall-mounted range hood.

Dynamic effects on containment of air-curtain fume hood operated with heat source.

This study focused on the leakage characteristics of the air-curtain fume hood that are subject to the influences of sash movement and walk-by motion while a high temperature heat source was operated in the hood. The flow visualization and trace gas test method were used to investigate the performance of the air-curtain fume hood. An electric heater was placed in the hood to simulate the heat source. The temperature of the heat source installed inside the air-curtain fume hood varied between 180°C and 300°C. Trace gas tests following the dynamic test methods of EN-14175 protocol were employed to measure the spillages of sulfur hexafluoride gas that were released in the hood. When subject to the influence of sash movement at a heat source temperature lower than 260°C, the leakage level was high at the suction velocity V(s) < 8 m/sec but was negligibly small at V(s) > 10 m/sec. When subject to the influence of people walk-by, the leakage level was relatively low at the suction velocity larger than 8 m/sec at sash height H = 50 cm. The height of the sash opening was a crucial parameter for the containment of the air-curtain fume hood. At the sash opening lower than about 25 cm, suction velocity less than or equal to 6 m/sec was enough to make the sulfur hexafluoride leakage less than the threshold value, 0.65 ppm, suggested by the BG Chemie. The air-curtain fume hood presented a great performance to resist the effect of drafts even though there was a high temperature heat source working in the hood.

Improving flow and spillage characteristics of range hoods by using an inclined air-curtain technique.

The current study developed a new type of range hood, which was termed an 'inclined air-curtain range hood', in order to improve the flow and performance of the conventionally used wall-mounted range hood. The flow characteristics and oil mist spillages of air-curtain and conventional range hoods under the influences of both a mannequin presence and a simulated walk-by motion were experimentally examined. The study examined flow patterns by using a laser-light-sheet-assisted smoke-flow visualization technique and diagnosed spillages by using the tracer gas concentration test method. A mannequin presented in front of the conventional hood induced turbulent dispersion of oil mists toward the chest and nose of the mannequin owing to the complex interaction among the suction, wake, and wall effect, while the inclined air-curtain hood presented excellent hood performance by isolating the oil mists from the mannequin with an air curtain and therefore could reduce spillages out into the atmosphere and the mannequin's breathing zone. Both flow visualization and the tracer gas test indicated that the air-curtain hood had excellent 'robustness' over the conventional hood in resisting the influence of walk-by motion. The air-curtain technique could drastically improve the flow characteristics and performance of the range hood by consuming less energy.

Positive Association between Indoor Gaseous Air Pollution and Obesity: An Observational Study in 60 Households.

This study aims to analyze whether exposure to indoor air pollution affects obesity. In our research, we recruited 127 participants, with an average age of 43.30 ± 15.38 years old, residing in 60 households. We monitored indoor air quality for 24 h, and conducted both questionnaire surveys and collected serum samples for analysis, to assess the relationship between indoor air pollutant exposure and obesity. After adjusting for demographic characteristics, the results showed that CO2 exposure is positively associated with being overweight and with a higher risk of being abdominally obese. Exposures to CO and formaldehyde were also positively associated with being overweight. IQR increase in TVOC was positively associated with increases in the risk of a high BMI, being abdominally obese and having a high body fat percentage. Two-pollutant models demonstrate that TVOCs presented the strongest risks associated with overweightness. We concluded that persistent exposure to indoor gaseous pollutants increases the risk of overweightness and obesity, as indicated by the positive association with BMI, abdominal obesity, and percentage body fat. TVOCs display the strongest contribution to obesity.