Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa.

Furniture is identified as a vital volatile organic compound (VOC) emission source in the indoor environment. Leather has become the most common raw and auxiliary fabric material for upholstered furniture, particularly with extensive consumption in sofas, due to its abundant resources and efficient functions. Despite being widely traded across the world, little research has been conducted on the VOCs released by leather materials and their health risk assessment in the indoor environment. Accordingly, this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure. Based on the ultra-fast gas phase electronic nose (EN) and GC-FID/Qtof, the substantial emissions of aliphatic aldehyde ketones (Aks), particularly hexanal, appear to be the cause of off-flavor in medium and low grade (MG and LG) sofa leathers. The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents. Given the abundance of VOC sources and the accumulation of health risks in the indoor environment, more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.

Children With Cerebral Palsy's Experiences With Adaptive Climbing: A Qualitative Study on Parents' Perspectives.

Background: Interest in adaptive sports for children with cerebral palsy (CP) is growing, but current evidence on the benefits and indications for one sport, adaptive climbing, is limited. Purpose: We sought to describe perceived changes observed by parents of children with CP who participated in adaptive climbing. Methods: Parents whose children with CP participated in 5 or more adaptive climbing sessions were eligible to participate and were emailed a recruitment letter and flyer. Data were collected through semi-structured interviews, using a moderator guide. Interviews were transcribed and content analyzed, with data grouped into concepts, categories, and themes until data saturation. Results: Ten parents (9 mothers, 1 father) of 10 children with CP (5 girls, 5 boys; ages 7 to 19 years) were interviewed for 15 to 45 minutes each, yielding 4 themes. First, parents perceived that adaptive climbing challenged the children physically (in reach, balance, strength, and head/neck and lower limb motion); second, that it sharpened children's cognitive skills (in focus, problem-solving, and strategic thinking); third, that it raised children's confidence (socially, physically, and emotionally); and fourth, that it expanded children's sense of what they could do (in mastering a challenge, claiming an athletic identity, and participating in a sport like their peers). Conclusions: In this qualitative study, parents described physical, cognitive, and psychosocial benefits of adaptive climbing for their children with CP. These descriptions can be used to inform future studies of children with CP who participate in adaptive climbing.

Size-resolved particulate matter inside selected fire stations and preliminary evaluation of the effectiveness of washing machines in reducing its concentrations.

The study aimed to determine and compare the mass concentration and size distribution of particulate matter (PM) at two Polish fire stations, one equipped with a washing machine intended for the decontamination of uniforms (FSN) and the other not equipped with this type of device (FSC), to assess the effectiveness of washing machines in reducing PM concentrations inside fire stations and estimate PM doses inhaled by firefighters while performing activities in truck bays and changing rooms during one work shift. The average PM concentrations at the FSN were 18.2-28.9 µg/m3 and 27.5-37.3 µg/m3, while at FSC they were 27.4-37.9 µg/m3 and 24.6-32.8 µg/m3 in the truck bays and changing rooms, respectively. At each measurement point, most of the PM mass (65-75%) was accumulated as fine particles. The dominance of fine particles in the total mass of PM results in high values of PM deposition coefficients (0.59-0.61) in three sections of the respiratory tract at each monitoring site. This study initially indicates the effectiveness of washing machines in reducing the concentration of fine particles and demonstrates the necessity, as well as directions for further research in this area.

A review of relevant parameters for assessing indoor air quality in educational facilities.

Indoor air quality (IAQ) in educational facilities is crucial due to the extended time students spend in those environments, affecting their health, academic performance, and attendance. This paper aimed to review relevant parameters (building characteristics and factors related with occupancy and activities) for assessing IAQ in educational facilities, and to identify the parameters to consider when performing an IAQ monitoring campaign in schools. It also intended to identify literature gaps and suggest future research directions. A narrative literature review was conducted, focusing on seven key parameters: building location, layout and construction materials, ventilation and air cleaning systems, finishing materials, occupant demographics, occupancy, and activities. The findings revealed that carbon dioxide (CO2) levels were predominantly influenced by classroom occupancy and ventilation rates, while particulate matter (PM) concentrations were significantly influenced by the building's location, design, and occupant activities. Furthermore, this review highlighted the presence of other pollutants, such as trace metals, polycyclic aromatic hydrocarbons (PAHs), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and radon, linking them to specific factors within the school environment. Different IAQ patterns, and consequently different parameters, were observed in various school areas, including classrooms, canteens, gymnasiums, computer rooms, and laboratories. While substantial literature exists on IAQ in schools, significant gaps still remain. This study highlighted the need for more studies in middle and high schools, as well as in other indoor microenvironments within educational settings beyond classrooms. Additionally, it underscored the need for comprehensive exposure assessments, long-term studies, and the impacts of new materials on IAQ including the effects of secondary reactions on surfaces. Seasonal variations and the implications of emerging technologies were also identified as requiring further investigation. Addressing those gaps through targeted research and considering the most updated standards and guidelines for IAQ, could lead to define more effective strategies for improving IAQ and safeguarding the students' health and performance.

Optimization of UWB indoor positioning based on hardware accelerated Fuzzy ISODATA.

With the development of wireless communication technology, Ultra-Wideband (UWB) has become an important solution for indoor positioning. In complex indoor environments, the influence of non-line-of-sight (NLOS) factors leads to increased positioning errors. To improve the positioning accuracy, fuzzy iterative self-organizing data analysis clustering algorithm (ISODATA) is introduced to process a large amount of UWB data to reduce the influence of NLOS factors, and to stabilize positioning error within 2 cm, enhances the accuracy of the positioning system. To further improve the running efficiency of the algorithm, FPGA is used to accelerate the key computational part of the algorithm, compared with running on the MATLAB platform, which improves the speed about 100 times, enhances the algorithm's computational speed dramatically.

Energy consumption and thermal comfort of rock-cut and modern buildings.

Energy consumption in the building sector justifies the necessity of knowing the thermal comfort perception of vernacular and modern architectural types, based on which a correct recognition was reached for the design of buildings suitable for the climatic conditions of each region. It should be determined that the different types of modern and traditional architecture are in the comfort level in harsh hot climate conditions and how much energy they consume to reach the comfort level. Despite consideration of energy consumption and thermal comfort in different buildings in Iran, there is no clear framework for evaluating these two parameters in different buildings and comparing them. This research aims to compare the indoor thermal comfort levels of vernacular architectural buildings and modern buildings in Iran's semi-hot and dry climate at the peak of summer heat and determine their energy consumption to reach the comfort level. This study has been accomplished by collecting field data, examining the indoor predicted mean vote (PMV) index of the buildings, and comparing them. It was found that rock-cut architecture buildings are in better thermal comfort conditions without energy consumption due to the use of groundmass temperature and low heat exchanges between the indoors and outdoors because of the thermal phase of the materials and the thickness of its layers. The indoor PMV average of rock-cut buildings in summer is -0.61; in modern buildings, it is 0.77, while these two building complexes are in the same climate and close. Also, the energy consumption to reach the comfort level in rock-cut buildings is zero, while modern buildings consume an average of 7.7 kW of electricity daily. The research results will lead to recognizing and modeling the climate design of vernacular architecture, which can be used in today's architecture to reduce energy consumption.

An observational analysis of the impact of indoor residual spraying in two distinct contexts of Burkina Faso.

BACKGROUND: Indoor residual spraying (IRS) is a cornerstone malaria control intervention in Burkina Faso. From 2018 to 2021, non-pyrethroid IRS was implemented annually in two regions of Burkina Faso with distinct malaria transmission patterns, concurrently with annual seasonal malaria chemoprevention (SMC), and a mass insecticide-treated net (ITN) distribution in 2019. METHODS: A retrospective quasi-experimental approach was used to evaluate the impact of the 2018, 2020, and 2021 IRS campaigns on routinely reported confirmed malaria case incidence at health facilities. The 2019 campaign was excluded due to lack of data reporting during a health sector strike. Controlled interrupted time series models were fit to detect changes in level and trend in malaria case incidence rates following each IRS campaign when compared to the baseline period 24-months before IRS. IRS districts Solenzo (Sudano-Sahelien climate), and Kampti (tropical climate) were compared with neighbouring control districts and the analyses were stratified by region. Modelled health facility catchment population estimates based on travel time to health facilities and weighted by non-malaria outpatient visits were used as an offset. The study period encompassed July 2016 through June 2022, excluding July 2018 to June 2019. RESULTS: District-level population and structure coverage achieved by IRS campaigns was greater than 85% in 2018, 2020, and 2021 in Solenzo and Kampti. In Solenzo a significant difference in malaria case incidence rates was detected after the 2018 campaign (IRR = 0.683; 95% CI 0.564-0.827) when compared to the control district. The effect was not detected following the 2020 or 2021 IRS campaigns. In Kampti, estimated malaria incidence rates were between 36 and 38% lower than in the control district following all three IRS campaigns compared to the baseline period. CONCLUSIONS: Implementation of IRS in Kampti, a tropical region of Burkina Faso, appeared to have a consistent significant beneficial impact on malaria case rates. An initial positive impact in Solenzo after the first IRS campaign was not sustained in the successive evaluated IRS campaigns. This study points to a differential effect of IRS in different malaria transmission settings and in combination with ITN and SMC implementation.

Human exposure risk of organic UV filters: A comprehensive analysis based on primary exposure pathways.

The exposure of organic UV filters has been increasingly confirmed to induce adverse effects on humans. However, the critical exposure pathway and the vulnerable population of organic UV filters are not clearly identified. This paper attempts to evaluate the health risk of commonly used organic UV filters from various exposure routes based on comprehensive analysis strategy. The estimated daily intakes (EDI) and hazard quotient (HQ) values of organic UV filters through four pathways (dermal exposure, indoor dust, indoor air, and drinking water) for various age groups were determined. Although the total HQ values (0.01-0.4) from comprehensive exposure of organic UV filters were below risk threshold (1.0), infants were identified as the most vulnerable population, with EDI (75.71 ng/kg-bw/day) of 2-3 times higher than that of adults. Additionally, the total EDI values of individual exposure pathways were estimated and ranked as follows: indoor air (138.44 ng/kg-bw/day) > sunscreen application (37.2 ng/kg-bw/day) > drinking water (21.87 ng/kg-bw/day) > indoor dust (9.24 ng/kg-bw/day). Moreover, we successfully tailored the Sankey diagram to depict the EDI proportion of individual organic UV filters from four exposure pathways. It was noted that EHMC (ethylhexyl methoxycinnamate) and EHS (ethylhexyl salicylate) dominated the contribution of EDI (72 %) via indoor air exposure routes. This study serves as a crucial reference for enhancing public health risk awareness concerning organic UV filters, with a special focus on the vulnerable populations such as infants and children.

Field measurement study of indoor thermal environment of badminton halls in a hot summer and cold winter region in different seasons in China.

The indoor thermal environment has a direct impact on human thermal comfort and health. In order to assess the status of the indoor thermal environment of typical sports buildings in hot summer and cold winter climate zones in China, 14 badminton halls in 10 cities in Hubei Province (including 5 venues in Wuhan) in this climate zone are chosen as research objects for field testing of indoor thermal environment parameters in 4 seasons. All the tested stadiums are naturally ventilated in non-event conditions. The results reveal that the average indoor temperature of badminton halls in summer is excessively high (i.e., 31.89 °C), which is higher than the regulation specified in JGJ31-2003 or GB-T18883-2022 on the reference interval of the indoor air temperature of venues in summer, (i.e., (26-28 °C) or (22-28 °C), respectively). The average indoor temperature of badminton halls in winter is too low (i.e., 12.95 °C), and it is lower than the recommendations of JGJ31-2003 or GB-T18883-2022 on the reference interval of the indoor air temperature of venues in winter (i.e., (16-18 °C) or (16-24 °C), respectively), relative humidity and air velocity are in the thermal comfort interval for all seasons, and the indoor thermal environment factors of badminton courts in spring and autumn meet the comfort requirements. The indoor and outdoor temperatures and the relative humidity of badminton courts are highly correlated. The indoor temperature and relative humidity vary according to changes in those factors outdoors, whereas the air velocity is not affected by outdoor changes. In the hot summer and cold winter climate zones, some discrepancies in the indoor temperature variation patterns of badminton halls at various altitudes are detectable. The results of this study aim to provide a solid basis for the development of indoor thermal-comfort standards for sports stadiums in China.

Highly Efficient Wide Bandgap Perovskite Solar Cells With Tunneling Junction by Self-Assembled 2D Dielectric Layer.

Reducing non-radiative recombination and addressing band alignment mismatches at interfaces remain major challenges in achieving high-performance wide-bandgap perovskite solar cells. This study proposes the self-organization of a thin two-dimensional (2D) perovskite BA2PbBr4 layer beneath a wide-bandgap three-dimensional (3D) perovskite Cs0.17FA0.83Pb(I0.6Br0.4)3, forming a 2D/3D bilayer structure on a tin oxide (SnO2) layer. This process is driven by interactions between the oxygen vacancies on the SnO2 surface and hydrogen atoms of the n-butylammonium cation, aiding the self-assembly of the BA2PbBr4 2D layer. The 2D perovskite acts as a tunneling layer between SnO2 and the 3D perovskite, neutralizing the energy level mismatch and reducing non-radiative recombination. This results in high power conversion efficiencies of 21.54% and 19.16% for wide-bandgap perovskite solar cells with bandgaps of 1.7 and 1.8 eV, with open-circuit voltages over 1.3 V under 1-Sun illumination. Furthermore, an impressive efficiency of over 43% is achieved under indoor conditions, specifically under 200 lux white light-emitting diode light, yielding an output voltage exceeding 1 V. The device also demonstrates enhanced stability, lasting up to 1,200 hours.

Evaluating the influence of ambient conditions in the cooking space of railway pantry car using selected thermal indices and physiological parameter.

BACKGROUND: Hot and humid indoor environment of the kitchen affects worker performance. The Indian Railway's pantry car culinary is one of them that cooks food for the on-board passengers, which could be bothered by the hot indoor climate. OBJECTIVE: The current study aimed to identify the indoor working environment of the railway "pantry car" using heat stress indices such as "Universal Thermal Climate Index-UTCI," "Wet-Bulb Globe Temperature-WBGT," "Discomfort Index-DI," "Tropical Summer Index-TSI," "Heat Index-HI," and Heart Rate-HR with clothing insulation. METHODS: The study was performed in 2018 (August-summer season) to collect field survey data on 6 railway pantry cars. Measurements were carried out during peak cooking times such as morning "7 : 00 am", day "11 : 30 am", evening "4 : 00 pm," and night "6 : 30 pm". This study's descriptive and Pearson's correlation analysis was accomplished using SPSS version 2016 software. RESULTS: The analysis results revealed that the average values were for UTCI (37.77±5.26°C), WBGT (30.42±2.28°C), DI (30.05±2.70°C), TSI (33.21±2.90°C), HI (48.53±4.86°C), correspondingly. During analysis, the strongest correlation association was observed between "TSI and DI" (r = 0.985, p < 0.000) and WBGT and TSI (r = 0.958, p < 0.000). A "significant correlation" was found between UTCI and HI (r = 0.637, p < 0.05). While no signification correlation was found between "heat stress indices and physiological parameters (p > 0.05)". CONCLUSION: In this study, all the heat stress index limit values showed highly harsh working conditions inside the pantry car, which created unfavorable circumstances for the culinarians. Inappropriate "ventilation design" could be a reason for discomfort in the railway pantry car.

Halogenation Strategy: Simple Wide Band Gap Nonfullerene Acceptors with the BODIPY-Thiophene-Backboned Polymer Donor for Enhanced Outdoor and Indoor Photovoltaics.

Researchers have been motivated to develop photovoltaic systems that can efficiently convert artificial light into power with the growing use of indoor electrical devices for the Internet of Things. Understanding the impact of molecular design strategies involving morphological optimization through the terminal group of the non-fullerene acceptors (NFAs) is crucial. This is critically important to enhancing the photovoltaic efficiency of organic photovoltaic devices under diverse irradiation conditions. Halogenation of terminal groups proves to be a standout approach for adjusting energy levels, refining light-harvesting capabilities, crystallinity, and bolstering the intermolecular stacking in NFAs. Herein, we have designed two simple NFAs, DICTF-4F and DICTF-4Cl, to explore the dihalogenation (F and Cl) effect on the terminal group on the optical and electrochemical properties. After combining with the BODIPY-thiophene-backboned donor polymer P(BdP-HT), the organic solar cells (OSCs) using an optimized active layer with P(BdP-HT):DICTF-4F and P(BdP-HT):DICTF-4Cl attained a power conversion efficiency (PCE) of about 8.03 and 14.16%, respectively, under 1 sun illumination. Moreover, the OSC-based P(BdP-HT):DICTF-4Cl active layer showed a PCE approaching 24% under 1000 lx indoor conditions.

Investigating exceedances of formaldehyde levels and source identification in offices of an academic medical institute.

OBJECTIVE: To investigate factors associated with indoor formaldehyde levels in office settings within an academic medical institute. METHODS: This cross-sectional study was conducted in 25 offices (261 workers) at a medical university in Thailand. Questionnaires gathered data on demographics, work patterns, and office equipment usage (printers, photocopiers, air fresheners, liquid paper, glue, cleaning agents and marker pens). The building environment was assessed by a multidisciplinary team. Formaldehyde levels and relevant parameters (temperature and relative humidity) were measured in each room both indoors and outdoors. A multiple linear regression model investigated the relationship between formaldehyde and office factors, controlling for room conditions. RESULTS: Median office formaldehyde levels were 442.1 µg/m3 (IQR: 343.8-908.7 µg/m3), exceeding World Health Organization and Thai guidelines. Photocopier use was significantly associated with higher levels of indoor formaldehyde (ß = 0.20, 95%CI: 0.30-0.37, p = 0.02). Air freshener use also showed a significant association (ß = 0.56, 95%CI: 0.30-0.81, p < 0.001). No correlation was found between the use of liquid paper, glue, printers, cleaning agents, or marker pens and indoor formaldehyde levels. CONCLUSIONS: Indoor formaldehyde levels in these offices exceeded the established guidelines. Use of photocopiers and air fresheners were associated with increased formaldehyde levels. Implementing interventions such as improved ventilation and regular screening is essential for creating healthier office environments.

Assessment of air quality in the Philadelphia, Pennsylvania subway.

BACKGROUND: Subways are popular and efficient modes of transportation in cities. However, people are exposed to high levels of particulate matter (PM) in subways. Subway air quality in the United States has been investigated in a few cities, but data is lacking on simultaneous measurement of several pollutants, especially ultrafine particles (UFP) and black carbon (BC), in combination with different size fractions of PM. OBJECTIVES: The goals of this study are to assess air quality in a belowground subway and compare it with outdoor ambient levels, to examine temporal variability of PM in the subway, and to analyze the correlation between PM and BC. METHODS: Particulate matter of varying sizes (PM1, PM2.5, PM10), UFP, and BC were measured using DustTrak, nanoparticle detector, and micro aethalometer, respectively. Measurements were made at the belowground subway platform and the aboveground street level at 15th Street subway station in Philadelphia during summer 2022. RESULTS: Belowground mean PM1, PM2.5, and PM10 were 112.2 ± 61.3 µg/m3, 120 ± 65.5 µg/m3, and 182.1 ± 132 µg/m3, respectively, which were 5.4, 5.7, and 7.6 times higher than the respective aboveground street levels. The UFP lung deposited surface area (LDSA) (59.4 ± 36.2 µm2/cm3) and BC (9.5 ± 5.4 µg/m3) belowground were 1.7 times and 10.7 times higher than the aboveground. The pollutant concentration varied from day-to-day on both the locations. A higher positive correlation was found between the belowground BC and PM2.5 (r = 0.51, p < 0.05) compared to the aboveground (r = 0.16, p < 0.05). IMPACT: This study showed high levels of particulate matter exposure at a belowground subway station in Philadelphia. Particulate matter levels were about 5 to 8 times higher at belowground subway station than the corresponding aboveground street level. Higher levels were also observed for UFP lung deposited surface area (LDSA), while black carbon levels showed the highest concentration at the belowground level by a factor of ten compared to the aboveground level. The study shows the need for air quality management at belowground subways to reduce particulate matter exposure for the commuters.

Air disinfection performance of upper-room ultraviolet germicidal irradiation (UR-UVGI) system in a multi-compartment dental clinic.

Multi-compartment dental clinics present significant airborne cross-infection risks. Upper-room ultraviolet germicidal irradiation (UR-UVGI) system have shown promise in preventing airborne pathogens, but its available application data are insufficient in multi-compartment dental clinics. Therefore, the UR-UVGI system's performance in a multi-compartment dental clinic was comprehensively evaluated in this study. The accuracy of the turbulence and drift flux models was verified by experimental data from ultrasonic scaling. The effects of the ventilation rate, irradiation zone volume, and irradiation flux on UR-UVGI performance were analyzed using computational fluid dynamics coupled with a UV inactivation model. Different patient numbers were considered. The results showed that UR-UVGI significantly reduced virus concentrations and outperformed increased ventilation rates alone. At a ventilation rate of six air changes per hour (ACH), UR-UVGI with an irradiation zone volume of 20% and irradiation flux of 5 µW/cm2 achieved a 70.44% average virus reduction in the whole room (WR), outperforming the impact of doubling the ventilation rate from 6 to 12 ACH without UR-UVGI. The highest disinfection efficiency of UR-UVGI decreased for WRs with more patients. The compartment treating patients exhibited significantly lower disinfection efficiency than others. Moreover, optimal UR-UVGI performance occurs at lower ventilation rates, achieving over 80% virus disinfection in WR. Additionally, exceeding an irradiation zone volume of 20% or an irradiation flux of 5 µW/cm2 notably reduces the improvement rates of UR-UVGI performance. These findings provide a scientific reference for strategically applying UR-UVGI in multi-compartment dental clinics.

Gas-phase and air-solid interface behavior of phthalate plasticizer and ozone: The influence of indoor mineral dust.

Indoor environments serve as reservoirs for a variety of emerging pollutants (EPs), such as phthalates (PAE), with intricate interactions occurring between these compounds and indoor oxidants alongside dust particles. However, the precise mechanisms governing these interactions and their resulting environmental implications remain unclear. By theoretical simulations, this work uncovers multi-functional compounds and high oxygen molecules as important products arising from the interaction between DEP/DEHP and O3, which are closely linked to SOA formation. Further analysis reveals a strong affinity of DEP/DEHP for mineral dust surfaces, with an adsorption energy of 22.11/30.91 kcal mol-1, consistent with a higher concentration of DEHP on the dust surface. Importantly, mineral particles are found to inhibit every step of the reaction process, albeit resulting in lower product toxicity compared to the parent compounds. Thus, timely removal of dust in an indoor environment may reduce the accumulation and residue of PAEs indoors, and further reduce the combined exposure risk produced by PAEs-dust. This study aims to enhance our understanding of the interaction between PAEs and SOA formation, and to develop a fundamental reaction model at the air-solid surface, thereby shedding light on the microscopic behaviors and pollution mechanisms of phthalates on indoor dust surfaces.

Assessment of indoor light-at-night exposure in children and adolescents during schooldays and weekends.

Light-At-Night (LAN) is increasingly recognized and may has adverse health effects on children and adolescents, yet few studies have reported objective indoor LAN exposure levels for children and adolescents. In this study, we measured the indoor LAN exposure levels and duration among 897 children and adolescents aged 6-14 in Beijing, China, using portable photometers during both school days and weekends. Results indicate that the median indoor LAN exposure from 9:00 p.m. to 7:00 a.m. was 5.1 lx, with 31.8% of the subjects experiencing an average exposure above 10 lx. Additionally, from the perspective of cumulative high exposure duration, children and adolescents were exposed to more than 10 lx for approximately 64 min from 9:00 p.m. to 7:00 a.m. During the entire nighttime (from self-reported bedtime to wake-up time), the median exposure was 2.1 lx, with 16.6% averaging exposures above 10 lx. Exposure levels were significantly higher on weekends than on schooldays. Both girls and upper-grade students had higher levels of exposure and longer durations of high exposure. Girls in grade 7 (OR:2.56, 95%CI: 1.68-3.88) experienced the highest LAN exposure in our subjects compared to boys in grade 1-4. Our findings underscore the importance of promoting healthy light exposure behaviors among children and adolescents and reducing their light exposure environments to mitigate the potential health impacts of LAN.

Assessing bias in personal exposure estimates when indoor air quality is ignored: A comparison between GPS-enabled mobile air sensor data and stationary outdoor sensor data.

Neglecting indoor air quality in exposure assessments may lead to biased exposure estimates and erroneous conclusions about the health impacts of exposure and environmental health disparities. This study assessed these biases by comparing two types of personal exposure estimates for 100 individuals: one derived from real-time particulate matter (PM2.5) measurements collected both indoors and outdoors using a low-cost portable air monitor (GeoAir2.0) and the other from PurpleAir sensor network data collected exclusively outdoors. The PurpleAir measurement data were used to create smooth air pollution surfaces using geostatistical methods. To obtain mobility-based exposure estimates, both sets of air pollution data were combined with the individuals' GPS tracking data. Paired-sample t-tests were then performed to examine the differences between these two estimates. This study also investigated whether GeoAir2.0- and PurpleAir-based estimates yielded consistent conclusions about gender and economic disparities in exposure by performing Welch's t-tests and ANOVAs and comparing their t-values and F-values. The study revealed significant discrepancies between GeoAir2.0- and PurpleAir-based estimates, with PurpleAir data consistently overestimating exposure (t = 5.94; p < 0.001). It also found that females displayed a higher average exposure than males (15.65 versus. 8.55 µg/m3) according to GeoAir2.0 data (t = 4.654; p = 0.055), potentially due to greater time spent indoors engaging in pollution-generating activities traditionally associated with females, such as cooking. This contrasted with the PurpleAir data, which indicated higher exposure for males (43.78 versus. 46.26 µg/m3) (t = 3.793; p = 0.821). Additionally, GeoAir2.0 data revealed significant economic disparities (F = 7.512; p < 0.002), with lower-income groups experiencing higher exposure-a disparity not captured by PurpleAir data (F = 0.756; p < 0.474). These findings highlight the importance of considering both indoor and outdoor air quality to reduce bias in exposure estimates and more accurately represent environmental disparities.

Wearable Sensor Node for Safety Improvement in Workplaces: Technology Assessment in a Simulated Environment.

Personal protective equipment (PPE) has been universally recognized for its role in protecting workers from injuries and illnesses. Smart PPE integrates Internet of Things (IoT) technologies to enable continuous monitoring of workers and their surrounding environment, preventing undesirable events, facilitating rapid emergency response, and informing rescuers of potential hazards. This work presents a smart PPE system with a sensor node architecture designed to monitor workers and their surroundings. The sensor node is equipped with various sensors and communication capabilities, enabling the monitoring of specific gases (VOC, CO2, CO, O2), particulate matter (PM), temperature, humidity, positional information, audio signals, and body gestures. The system utilizes artificial intelligence algorithms to recognize patterns in worker activity that could lead to risky situations. Gas tests were conducted in a special chamber, positioning capabilities were tested indoors and outdoors, and the remaining sensors were tested in a simulated laboratory environment. This paper presents the sensor node architecture and the results of tests on target risky scenarios. The sensor node performed well in all situations, correctly signaling all cases that could lead to risky situations.

Indoor Air Quality Assessments in 10 Long-Term Care Facilities During the COVID-19 Pandemic, California, 2021-2023.

OBJECTIVES: This study aimed to assess indoor air quality (IAQ) in long-term care facilities (LTCFs) in California during the COVID-19 pandemic and evaluate their implementation of IAQ best practices described by public health authorities to control respiratory pathogen transmission via inhalation. DESIGN: This observational study conducted IAQ assessments in a convenience sample of LTCFs to gather qualitative data on the implementation of IAQ best practices. The design included 5 pilot visits to develop a standardized method of data collection and then systematic data collection at 10 facilities. SETTING AND PARTICIPANTS: The study focused on 10 LTCFs across California, chosen from facilities that responded to flyers advertising free IAQ assessments. Some of the facilities had previously experienced COVID-19 outbreaks affecting residents and staff. METHODS: State health department industrial hygienists performed site visits to collect data on each facility's heating, ventilation, and air-conditioning (HVAC) system operation, outdoor air introduction, recirculated air filtration, use of portable air cleaners, and directional airflow in isolation areas to evaluate implementation of IAQ best practices in each of these areas. Qualitative data were obtained through visual inspections and interviews with maintenance personnel. RESULTS: Findings indicated suboptimal implementation of IAQ best practices across the assessed facilities: no facility operated HVAC systems continuously, 40% had all outdoor air dampers open, 20% used MERV-13 or higher rated filters, 20% used portable air cleaners, and 20% performed directional airflow assessment and management for isolating COVID-19 cases. CONCLUSIONS AND IMPLICATIONS: Most LTCFs assessed were not adhering to IAQ best practices, highlighting a significant opportunity for improvement. IAQ best practices described in this study are achievable with existing systems and are critical for reducing virus transmission through the air in LTCFs. The findings underscore the need for more systematic assessments and improvements in IAQ within LTCFs to protect staff and residents.