Study on the ability of indoor plants to absorb and purify benzene pollution.

The ability of indoor plants to purify benzene pollution is the basic basis for the selection of plants for ecological remediation of indoor benzene pollution. In this study, the purification rate and the purification amount per unit leaf area of 13 test plants at three benzene concentrations were determined by indoor fumigation experiments, and the benzene absorption and purification abilityability of indoor plants were comprehensively evaluated. The results showed that (1) there was a significant correlation between benzene concentration and purification rate and purification amount per unit leaf area. (2) At the three concentrations, Spathiphyllum floribundum showed the highest purification rate and Sansevieria trifasciata var. laurentii showed the highest purification per unit leaf area. (3) The combined results showed that Sansevieria trifasciata var. laurentii, Spathiphyllum floribundum and Aloe arborescens were the strongest absorbers and purifiers, while Podocarpus nagi and Anthurium andraeanum 'Pink champin' had the weakest absorption and purification capacity. The results of this study provide a theoretical basis and reference for the selection of plants with strong capacities to adsorb and purify benzene pollution in indoor air.

Fungal diversity differences in the indoor dust microbiome from built environments on earth and in space.

Human occupied built environments are no longer confined to Earth. In fact, there have been humans living and working in low-Earth orbit on the International Space Station (ISS) since November 2000. With NASA's Artemis missions and the age of commercial space stations set to begin, more human-occupied spacecraft than ever will be in Earth's orbit and beyond. On Earth and in the ISS, microbes, especially fungi, can be found in dust and grow when unexpected, elevated moisture conditions occur. However, we do not yet know how indoor microbiomes in Earth-based homes and in the ISS differ due to their unique set of environmental conditions. Here we show that bacterial and fungal communities are different in dust collected from vacuum bags on Earth and the ISS, with Earth-based homes being more diverse (465 fungal OTUs and 237 bacterial ASVs) compared to the ISS (102 fungal OTUs and 102 bacterial ASVs). When dust from these locations were exposed to varying equilibrium relative humidity conditions (ERH), there were also significant fungal community composition changes as ERH and time elevated increased (Bray Curtis: R2 = 0.35, P = 0.001). These findings can inform future spacecraft design to promote healthy indoor microbiomes that support crew health, spacecraft integrity, and planetary protection.

Radon Exposure Assessment in Occupational and Environmental Settings: An Overview of Instruments and Methods.

Radon is a naturally occurring noble radioactive gas that poses significant health risks, particularly lung cancer, due to its colorless, odorless, and tasteless nature, which makes detection challenging without formal testing. It is found in soil, rock, and water, and it infiltrates indoor environments, necessitating regulatory standards and guidelines from organizations such as the Environmental Protection Agency, the World Health Organization, and the Occupational Health and Safety Agency to mitigate exposure. In this paper, we present various methods and instruments for radon assessment in occupational and environmental settings. Discussion on long- and short-term monitoring, including grab sampling, radon dosimetry, and continuous real-time monitoring, is provided. The comparative analysis of detection techniques-active versus passive-is highlighted from real-time data and long-term exposure assessment, including advances in sensor technology, data processing, and public awareness, to improve radon exposure evaluation techniques.

Monitoring the ventilation of living spaces to assess the risk of airborne transmission of infection using a novel Pocket CO2 Logger to track carbon dioxide concentrations in Tokyo.

We employed carbon dioxide (CO2) concentration monitoring using mobile devices to identify location-specific risks for airborne infection transmission. We lent a newly developed, portable Pocket CO2 Logger to 10 participants, to be carried at all times, for an average of 8 days. The participants recorded their location at any given time as cinema, gym, hall, home, hospital, other indoors, other outgoings, pub, restaurant, university, store, transportation, or workplace. Generalized linear mixed model was used for statistical analysis, with the objective variable set to the logarithm of CO2 concentration. Analysis was performed by assigning participant identification as the random effect and location as the fixed effect. The data were collected per participant (seven males, four females), resulting in a total of 12,253 records. Statistical analysis identified three relatively poorly ventilated locations (median values > 1,000 ppm) that contributed significantly (p < 0.0001) to CO2 concentrations: homes (1,316 ppm), halls (1,173 ppm), and gyms (1005ppm). In contrast, two locations were identified to contribute significantly (p < 0.0001) to CO2 concentrations but had relatively low average values (<1,000 ppm): workplaces (705 ppm) and stores (620 ppm). The Pocket CO2 Logger can be used to visualize airborne infectious transmission risk by location to help guide recommendation regarding infectious disease policies, such as restrictions on human flow and ventilation measures and guidelines. In the future, large-scale surveys are expected to utilize the global positioning system, Wi-Fi, or Bluetooth of an individual's smartphone to improve ease and accuracy.

Quantitative evaluation of the impact of indoor relative humidity on deposition of aerosols generated during tooth grinding in a real-world clinical setting.

OBJECTIVES: Exposure to aerosol particles generated from tooth grinding has a negative impact on the health of dental personnel. The aim of this study was to quantitatively analyze the impact of indoor relative humidity (IRH) on the deposition of these suspended particles in a well-controlled dental environment. MATERIALS AND METHODS: In this study, a humidity control system was employed to effectively regulate and maintain indoor relative humidity (IRH). A novel computer-assisted numerical control system was developed to pre-treat the molar specimens, and accurately simulate clinical tooth grinding procedures. Each procedure was performed in triplicate, with an online real-time particle counter (ORPC; TR-8301, TongrenCo.) measuring aerosol production. All testing devices were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Kruskal-Wallis/ Dunn's post hoc test with Bonferroni correction, p < 0.05). RESULTS: The findings showed that with increasing IRH, the maximum peak concentration of aerosol particles decreased by 397% from 6.51 × 107 particles/m3 at 30% to 1.64 × 107 particles/m3 at 80%. The Kruskal-Wallis test results indicated a statistically significant effect of IRH on the aerosol increment (p < 0.05). CONCLUSIONS: Increasing the IRH level can effectively promote the deposition of aerosol particles, with a return to baseline within 15 min after reaching 60% or above. CLINICAL RELEVANCE: Our study suggested that maintaining IRH above 70% during the cleaning process, allowing natural recovery to ambient humidity levels within 15 min after cleaning, and taking basic precautions, may lead to an adequate reduction in the possible health risks of aerosol contamination.

Emission of volatile organic compounds during open fire cooking with wood biomass: Traditional three-stone open fire vs. gasifier cooking stove in rural Kenya.

Cooking with wood biomass fuels releases hazardous air pollutants, including volatile organic compounds (VOCs), that often disproportionally affect women and children. This study, conducted in Kwale and Siaya counties in Kenya, employed thermal desorption gas chromatography - mass spectrometry to analyse VOC emissions from cooking with a wood biomass three-stone open fire vs. top-lit updraft gasifier stove. In kitchens with adequate ventilation, total VOC levels increased from 35-252 µg∙m-3 before cooking to 2235-5371 µg∙m-3 during open fire cooking, whereas use of a gasifier stove resulted in reduced emissions from cooking by 48-77 % (506-2778 µg∙m-3). However, in kitchens with poor ventilation, there was only a moderate difference in total VOC levels between the two methods of cooking (9034-9378 µg∙m-3 vs. 6727-8201 µg∙m-3 for the three-stone open fire vs. gasifier stove, respectively). Using a non-target screening approach revealed significantly increased levels of VOCs, particularly benzenoids, oxygenated and heterocyclic compounds, when cooking with the traditional open fire, especially in closed kitchens, highlighting the effects of poor ventilation. Key hazardous VOCs included benzene, naphthalene, phenols and furans, suggesting potential health risks from cooking. In kitchens with good ventilation, use of the gasifier stove markedly reduced emissions of these priority toxic VOCs compared to cooking with an open fire. Thus, substituting open fires with gasifier stoves could help to improve household air quality and alleviate health risks. The study revealed that VOCs were present prior to cooking, possibly originating from previously cooked food (buildup) or the outside environment. VOC emissions were also exacerbated by reduced air flow in high humidity during rainfall, suggesting an area for further research. The findings underscore the importance of adopting cleaner cooking technologies and enhancing kitchen ventilation to mitigate the impacts of VOCs in developing countries.

Early life ambient air pollution, household fuel use, and under-5 mortality in Ghana.

INTRODUCTION: Environmental exposures, such as ambient air pollution and household fuel use affect health and under-5 mortality (U5M) but there is a paucity of data in the Global South. This study examined early-life exposure to ambient particulate matter with a diameter of 2.5 µm or less (PM2.5), alongside household characteristics (including self-reported household fuel use), and their relationship with U5M in the Navrongo Health and Demographic Surveillance Site (HDSS) in northern Ghana. METHODS: We employed Satellite-based spatiotemporal models to estimate the annual average PM2.5 concentrations with the Navrongo HDSS area (1998 to 2016). Early-life exposure levels were determined by pollution estimates at birth year. Socio-demographic and household data, including cooking fuel, were gathered during routine surveillance. Cox proportional hazards models were applied to assess the link between early-life PM2.5 exposure and U5M, accounting for child, maternal, and household factors. FINDINGS: We retrospectively studied 48,352 children born between 2007 and 2017, with 1872 recorded deaths, primarily due to malaria, sepsis, and acute respiratory infection. Mean early-life PM2.5 was 39.3 µg/m3, and no significant association with U5M was observed. However, Children from households using "unclean" cooking fuels (wood, charcoal, dung, and agricultural waste) faced a 73 % higher risk of death compared to those using clean fuels (adjusted HR = 1.73; 95 % CI: 1.29, 2.33). Being born female or to mothers aged 20-34 years were linked to increased survival probabilities. INTERPRETATION: The use of "unclean" cooking fuel in the Navrongo HDSS was associated with under-5 mortality, highlighting the need to improve indoor air quality by introducing cleaner fuels.

Evaluation of particle and volatile organic compound emissions during the use of 3D pens.

This study investigated particle and volatile organic compound (VOC) emission rates (ER) from 3D pens, which are increasingly popular in children's toys. Nine filaments and two 3D pens were evaluated using a flow tunnel, a scanning mobility particle sizer, a proton-transfer-reaction time-of-flight mass spectrometer for particles, and a thermal desorption-gas chromatography-mass spectrometer for VOCs. Results showed that the ERs varied with the pen type, filament, and brand. The particle ER was highest for acrylonitrile butadiene styrene (ABS), followed by polylactic acid (PLA) and polycaprolactone (PCL). Notably, ERs of 83 % and 33 % of ABS and PLA filaments exceeded the maximum allowable particle ER (MAER; 5 × 109 particles/min) for 3D printers but were lower than the VOC MAER (173 µg/min in the office). Different filaments emitted diverse VOCs; ABS emitted styrene and benzene, PLA emitted lactide, and PCL emitted phenol. While particle ERs from 3D pens were comparable to those from printers, the total VOC ERs from 3D pens were slightly lower. Caution is warranted when using 3D pens because of potential health risks, especially their prolonged use, proximity to the breathing zone, and usage by children. This study highlights the need for considering particles and VOCs when assessing the safety of 3D pens, emphasizing awareness of potential hazards, particularly in child-oriented settings.

Nitrogen dioxide exposure, health outcomes, and associated demographic disparities due to gas and propane combustion by U.S. stoves.

Gas and propane stoves emit nitrogen dioxide (NO2) pollution indoors, but the exposures of different U.S. demographic groups are unknown. We estimate NO2 exposure and health consequences using emissions and concentration measurements from >100 homes, a room-specific indoor air quality model, epidemiological risk parameters, and statistical sampling of housing characteristics and occupant behavior. Gas and propane stoves increase long-term NO2 exposure 4.0 parts per billion volume on average across the United States, 75% of the World Health Organization's exposure guideline. This increased exposure likely causes ~50,000 cases of current pediatric asthma from long-term NO2 exposure alone. Short-term NO2 exposure from typical gas stove use frequently exceeds both World Health Organization and U.S. Environmental Protection Agency benchmarks. People living in residences <800 ft2 in size incur four times more long-term NO2 exposure than people in residences >3000 ft2 in size; American Indian/Alaska Native and Black and Hispanic/Latino households incur 60 and 20% more NO2 exposure, respectively, than the national average.

Microbial dynamics and climatic interactions in pig sheds: Insights into airborne microbes and particulate matter concentrations.

Emissions of airborne pollutants from livestock buildings affect indoor air quality, the health and well-being of farmers, animals and the environment. This study aimed to evaluate the microbial count within pig sheds and its relationship with meteorological variables (temperature, relative humidity and air velocity) and particulate matter (PM10 and PM2.5) and microbial diversity. Sampling was conducted both inside and outside of two pig sheds over three seasons (summer, rainy and winter), with regular monitoring at fortnightly intervals. Results showed that the bacterial and fungal counts ranged from 0.07 to 3.98 x 103 cfu/m3 inside the sheds and 0.01 to 1.82 x 103 cfu/m3 outside. Seasonal variations were observed, with higher concentrations of particulate matter detected during the winter season, followed by summer. Climatic variables such as temperature, air velocity and relative humidity demonstrated significant impacts on the abundance of Enterobacteriaceae and fungi, while air velocity specifically influenced the presence of mesophilic bacteria and staphylococci. Importantly, no significant disparities were found between microbial counts and particulate matter levels. Staphylococcaceae emerged as the predominant bacterial family, while Aspergillus and Cladosporium spp. were the dominant fungal species within the pig sheds. The average levels of airborne bacteria and fungi in pig sheds were found to be within the recommended range, which can be attributed to the loose housing design and lower animal population on the farms.

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

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

Increase of the indoor concentration of volatile organic compounds after the use of incense and scented candle in studio apartments determined using passive sampling.

Burning incenses and scented candles may provide harmful chemicals. Although many studies have evaluated volatile organic chemicals emitted by their use and related health risks, extension of our understanding for guiding appropriate use under various use conditions is necessary. In this study, emission characteristics of commercial incenses and scented candles were evaluated in a laboratory chamber using real-time measurement and the time-weighted average exposure concentrations of monoaromatic compounds and monoterpenes were assessed using passive samplers while volunteers living in a studio apartment use them. After burning incense, the average levels of benzene increased from 1.4 to 100 µg m-3. The presence of a wood core in commercial incense products was the main cause of high benzene emission by burning them although the increase in benzene was also influenced by factors such as the brand of the products, the number of incense sticks burned, the duration of each burning session, and ventilation period. Electrical warming of scented candles increased the levels of monoterpenes by factors of 16-30 on average. Considering the emission characteristics found in this study, exposure to benzene and monoterpenes could be mitigated by cautious use of those products in residential areas.

Dust dynamics: distribution patterns of semi-volatile organic chemicals across particle sizes in varied indoor microenvironments.

An extensive analysis of the distribution patterns of three distinct classes of semi-volatile organic chemicals (SVOCs)-phthalates (PAEs), organophosphate flame retardants (OPFRs), and polycyclic aromatic hydrocarbons (PAHs)-across four distinct size fractions of dust (25, 50, 100, and 200 µm) was conducted. The dust samples were sourced from AC filter, covered car parking lots, households, hotels, mosques, and car floors. To generate the four fractions, ten dust samples from each microenvironment were pooled and sieved utilizing sieving apparatus with the appropriate mesh size. Selected SVOCs were quantified utilizing gas chromatography-mass spectrometry in electron impact (EI) mode. Results unveiled diverse contamination levels among dust fractions, showcasing car parking lot dust with the lowest chemical contamination, while car floor dust displayed the highest levels of PAHs and OPFRs, peaking at 28.3 µg/g and 43.2 µg/g, respectively. In contrast, mosque and household floor dust exhibited the highest concentrations of phthalates, with values of 985 µg/g and 846 µg/g, respectively. Across the analyzed microenvironments, we observed a trend where concentrations of SVOCs tended to rise as dust particles decreased in size, forming a visually striking pattern. This phenomenon was particularly pronounced in dust samples collected from car floors and parking lots. Among SVOCs, PAEs emerged as the predominant contributors with > 90% followed by OPFRs and PAHs. The high levels of OPFRs in car floor dust align logically with the fact that numerous interior components of cars are treated with OPFRs, within a compact indoor microenvironment, to comply to fire safety regulations. Furthermore, petroleum products are a major source of PAHs in the environment and all the sampled cars in the study had combustion engines. Consequently, car dust is more likely to be polluted with PAHs stemming from petroleum combustion. Although previous investigations have noted an increase in heavy metals and brominated flame retardants with decreasing dust particles, this is the first study analyzing these SVOCs in different fractions of dust from various microenvironments. However, aside from two specific microenvironments, the observed pattern of escalating SVOC concentrations with smaller dust particle sizes was not corroborated among the examined microenvironments. This divergence in concentration trends suggests the potential involvement of supplementary variables in influencing SVOC distributions within dust particles.

Evaluation of consumer digital radon measurement devices: a comparative analysis.

Kansas State University (KSU) Engineering Extension conducted an abridged evaluation of eight consumer grade digital radon monitors. Using the KSU secondary radon chamber, these devices were exposed to three different radon concentrations for 7 d in average household temperature and relative humidity conditions. The three different radon concentration ranges used were: 12.8 pCi L-1to 15.5 pCi L-1(473.6 Bq m-3-573.5 Bq m-3), 27.7 pCi L-1to 29.4 pCi L-1(1024.9-10 857.8 Bq m-3), and ambient room level average radon concentration of 0.6 pCi L-1(22.2 Bq m-3). The American National Standards Institute/American Academy of Radon Scientists and Technologists Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air (ANSI/AARST MS-PC) (ANSI/AARST MS-PC 2022Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air(AARST Radon Standards)) minimum performance metrics were used to evaluate the accuracy and precision of each model type for each radon concentration tested. The eight different device models performed within the 0 ± 25% requirement for the individual percent error (IPE) for radon concentrations between 27.7 pCi L-1and 29.4 pCi L-1(1024.9-10 857.8 Bq m-3). For radon concentrations between 12.8 pCi L-1and 15.5 pCi L-1(444-592 Bq m-3) seven of the eight monitors fell within the IPE requirement and for ambient room radon concentrations six of the eight monitors fell within the IPE requirement for the ANSI/AARST MS-PC minimum performance requirement (ANSI/AARST MS-PC 2022Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air(AARST Radon Standards)) ranges. All eight device models fell within the ± 15% ANSI/AARST MS-PC minimum performance requirement (ANSI/AARST MS-PC 2022Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air(AARST Radon Standards)) coefficient of variation (CV) range for radon concentrations between 12.8 pCi L-1and 15.5 pCi L-1(444-592 Bq m-3) and for radon concentrations between 27.7 pCi L-1and 29.4 pCi L-1(1024.9-10 857.8 Bq m-3). In the future, evaluating the performance of these models over time to observe their long term accuracy and precision is anticipated.

Phthalate alternatives and their monoesters in indoor dust from several regions, China and implications for human exposure.

Household products, in response to regulations, increasingly incorporate phthalate (PAE) alternatives instead of traditional PAEs. However, limited information exists regarding the fate and exposure risk of these PAE alternatives and their monoesters in indoor environments. The contamination levels of PAE alternatives and their monoesters in indoor dust might vary across regions due to climate, population density, industrial activities, and interior decoration practices. By analyzing indoor dust samples from six geographical regions across China, this study aims to shed light on concentrations, profiles, and human exposure to 12 PAE alternatives and 9 their monoesters. Bis(2-ethylhexyl) benzene-1,4-dicarboxylate (DEHTP), tributyl 2-acetyloxypropane-1,2,3-tricarboxylate (ATBC), and tris(2-ethylhexyl) benzene-1,2,4-tricarboxylate (TOTM) were the main PAE alternatives in dust across all regions. The total concentrations of 12 PAE alternatives ranged from 0.125 to 4160 µg/g in indoor dust. High molecular weight PAE alternatives had significantly correlated concentrations (p < 0.05) based on Spearman analysis, suggesting their co-use in heat-resistant plastic products. A collective of nine monoesters were identified in most samples, with total concentrations ranging from 0.048 to 29.6 µg/g. The median concentrations of PAE alternatives were highest in North China (66.8 µg/g), while those of monoesters were highest in Southwest China (6.93 µg/g). A significant correlation (p < 0.05) between the concentrations of DEHTP and its monoester suggested that degradation could be a potential source of monoesters. Although hazard quotients (HQs) have been calculated to suggest that the current exposure is unlikely to pose a significant health risk, the lack of toxicity threshold data and the existence of additional exposure pathways necessitate a further confirmation.

Children's exposure to brominated flame retardants in the home: The TESIE study.

Due to differences in chemical properties and half-lives, best practices for exposure assessment may differ for legacy versus novel brominated flame retardants (BFRs). Our objective was to identify the environment matrix that best predicted biomarkers of children's BFR exposures. Paired samples were collected from children aged 3-6 years and their homes, including dust, a small piece of polyurethane foam from the furniture, and a handwipe and wristband from each child. Biological samples collected included serum, which was analyzed for 11 polybrominated diphenyl ethers (PBDEs), and urine, which was analyzed for tetrabromobenzoic acid (TBBA), a metabolite of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB). Significant positive correlations were typically observed between BFRs measured in dust, handwipes and wristbands, though wristbands and handwipes tended to be more strongly correlated with one another than with dust. PBDEs, EH-TBB and BEH-TEBP were detected in 30% of the sofa foam samples, suggesting that the foam was treated with PentaBDE or Firemaster® 550/600 (FM 550/600). PBDEs were detected in all serum samples and TBBA was detected in 43% of urine samples. Statistically significant positive correlations were observed between the environmental samples and serum for PBDEs. Urinary TBBA was 6.86 and 6.58 times more likely to be detected among children in the highest tertile of EH-TBB exposure for handwipes and wristbands, respectively (95 % CI: 2.61, 18.06 and 1.43, 30.05 with p < 0.001 and 0.02, respectively). The presence of either PentaBDE or FM 550/600 in furniture was also associated with significantly higher levels of these chemicals in dust, handwipes and serum (for PBDEs) and more frequent detection of TBBA in urine (p = 0.13). Our results suggest that children are exposed to a range of BFRs in the home, some of which likely originate from residential furniture, and that silicone wristbands are a practical tool for evaluating external exposure to both legacy and novel BFRs.

Occurrence and seasonal variations of organophosphate flame retardants in air and dust from college microenvironments at Qingdao, China: Implications for student's exposure and risk assessment.

Organophosphate flame retardants (OPFRs) are widely used as alternatives to brominated flame retardants in a variety of consumer products and their consumption has continuously increased in recent years. However, their concentrations and human exposures in indoor microenvironments, particularly in a university environment, have received limited attention. In this study, the concentrations and seasonal variations of 15 OPFRs were assessed in typical microenvironments of two universities, including dormitories, offices, public microenvironments (PMEs: classroom, dining hall, gymnasium and library), and laboratories on the northern coast of China. Analysis of the OPFRs in both air and dust samples indicated widespread distribution in college campuses. The average concentration of ∑15OPFRs in the winter (12,774.4 ng/g and 5.3 ng/m3 for dust and air, respectively) was higher than in the summer (2460.4 ng/g and 4.6 ng/m3 for dust and air, respectively). The dust and air samples collected from PMEs and laboratories exhibited higher concentrations of OPFRs, followed by offices and dormitories. An equilibrium was reached between dust and air in all collected microenvironments. The daily intakes of OPFRs were significantly lower than the reference dose. Dust ingestion was the primary intake pathway in the winter, while inhalation and dust ingestion were the main intake pathways in the summer. The non-carcinogenic hazard quotients fell within the range of 10-7-10-3 in both the summer and winter, which are below the theoretical risk threshold. For the carcinogenic risk, the LCR values ranged from 10-10 to 10-8, indicating no elevated carcinogenic risk due to TnBP, TCEP, and TDCP in indoor dust and air.

Effects of indoor air pollution from household solid fuel use on the risk of gastrointestinal and liver diseases in middle aged and elderly adults.

Solid fuels are widely used in China and increase the concentrations of indoor air pollutants. Nevertheless, there is limited longitudinal evidence linking solid fuel use and Gastrointestinal (GI) and liver diseases. This study aimed to prospectively investigate the association between household solid fuel use and the risk of GI and liver diseases in middle aged and elderly adults. This work was based on the China Health and Retirement Longitudinal Study (CHARLS). Longitudinal data incorporate with cross-sectional data were analyzed. Compared with individuals using clean fuel for cooking, solid fuel users were observed to have higher risk of GI diseases (OR in 2011, 2013, 2015, 2018 wave separately: 1.37, 95 % CI: 1.24-1.50, P < 0.001; 1.24, 95 % CI: 1.11-1.39, P < 0.001; 1.18, 95 % CI: 1.06-1.33, P < 0.001; 1.23, 95 % CI: 1.04-1.45, P < 0.05). The associations between solid fuel use and liver diseases were not significant in most of the groups. Participants transforming from solid to clean cooking fuels had lower risk of GI and liver diseases than persistent solid fuel users. Moreover, biomass cooking fuel users were at a significant higher risk of both liver and GI diseases compared with clean fuel users. Overall, household solid fuel use, especially for cooking, was related to higher risk of GI and liver diseases, while switching from solid to clean fuels could reduce this risk. Using biomass for cooking was identified to be more associated with the increasing risk of GI and liver diseases than cooking with coal.

Air Quality Monitoring Using Low-Cost Sensors in Urban Areas of Jodhpur, Rajasthan.

Air pollution poses a significant health hazard in urban areas across the globe, with India being one of the most affected countries. This paper presents environmental monitoring study conducted in Jodhpur, Rajasthan, India, to assess air quality in diverse urban environments. The study involved continuous indoor and outdoor air quality monitoring, focusing on particulate matter (PM2.5) levels, bioaerosols, and associated meteorological parameters. Laser sensor-based low-cost air quality monitors were utilized to monitor air quality and Anderson 6-stage Cascade Impactor & Petri Dish methods for bioaerosol monitoring. The study revealed that PM2.5 levels were consistently high throughout the year, highlighting the severity of air pollution in the region. Notably, indoor PM2.5 levels were often higher than outdoor levels, challenging the common notion of staying indoors during peak pollution. The study explored the spatial and temporal diversity of air pollution across various land-use patterns within the city, emphasizing the need for tailored interventions in different urban areas. Additionally, bioaerosol assessments unveiled the presence of pathogenic organisms in indoor and outdoor environments, posing health risks to residents. These findings underscore the importance of addressing particulate matter and bioaerosols in air quality management strategies. Despite the study's valuable insights, limitations, such as using low-cost air quality sensors and the need for long-term data collection, are acknowledged. Nevertheless, this research contributes to a better understanding of urban air quality dynamics and the importance of public awareness in mitigating the adverse effects of air pollution. In conclusion, this study underscores the urgent need for effective air quality management strategies in urban areas. The findings provide valuable insights for policymakers and researchers striving to address air pollution in rapidly urbanizing regions.

A Retrospective Analysis of Indoor CO2 Measurements Obtained with a Mobile Robot during the COVID-19 Pandemic.

This work presents a retrospective analysis of indoor CO2 measurements obtained with a mobile robot in an educational building after the COVID-19 lockdown (May 2021), at a time when public activities resumed with mandatory local pandemic restrictions. The robot-based CO2 measurement system was assessed as an alternative to the deployment of a net of sensors in a building in the pandemic period, in which there was a global stock outage of CO2 sensors. The analysis of the obtained measurements confirms that a mobile system can be used to obtain interpretable information on the CO2 levels inside the rooms of a building during a pandemic outbreak.