TVOC - Revisited

Development and characterization of an automated system for generation and collection of cigarette smoke (ASGCS) for rapid and accurate exposure and toxicity assessment

Whole cigarette smoke condensate (WCSC) is a crucial tool for assessing tobacco product toxicity, offering advantages in storage, transportation, and concentration control. However, the lack of an automated system for WCSC production poses challenges in ensuring batch-to-batch consistency and test article reproducibility, both of which are essential for reliable toxicity evaluation. In this study, we developed and characterized an automated system for the generation and collection of cigarette smoke (ASGCS) to efficiently produce WCSC. Under Health Canada Intense smoking conditions, the ASGCS achieved a low smoke leakage rate of 9.45 ± 0.47 %, facilitating the collection of total particulate matter (TPM) at a relatively high concentration of 21.2 ± 0.2 mg cig-1. Nicotine and total volatile organic compound concentrations in WCSC prepared using the ASGCS were 1.25 ± 0.01 μg cig-1 and 2276 μg cig-1, corresponding to transfer rates of approximately 65 % and 135 % relative to cigarette smoke, respectively. WCSC exposure demonstrated a dose-dependent decrease in cell viability, with an IC50 of 0.26 mg mL-1 (R2 = 0.9171). These findings confirm the physical performance of ASGCS and the chemical and biological reliability of WCSC produced using this system. The ASGCS offers a robust platform for the rapid and accurate assessment of tobacco product toxicity.

Global perspectives on indoor phthalates and alternative plasticizers: Occurrence and key transport parameters

Phthalates and emerging alternative plasticizers have garnered significant attention due to their ubiquitous presence indoors and potential adverse health effects. However, the occurrences and key transport parameters of indoor alternative plasticizers have not been sufficiently summarized and analyzed, complicating exposure evaluation and pollution control efforts. This study addresses the gap by providing a comprehensive overview of the occurrence and key transport parameters of the most reported plasticizers, including 10 phthalates and 14 alternative plasticizers. The plasticizer content in source materials was found to range up to 27.6 wt%. An empirical formula was developed to predict the surface-adjacent gaseous plasticizer concentration (y0) of source materials, with values ranging from 0.015 to 64.7 μg/m3. Variations in plasticizer concentrations across source, gas, particle, and dust phases were thoroughly analyzed over both temporal and spatial dimensions from a global perspective, indicating significant differences between continents over time. A detailed investigation of phthalate regulations across continents suggests that the earlier enactment of phthalate bans in Europe is likely a key factor contributing to the most significant decrease in indoor phthalate concentrations. Furthermore, after systematically reviewing mass-transfer and partitioning theories, we developed empirical formulas to predict mass-transfer coefficients (hm) and partition coefficients (K) for both phthalates and alternative plasticizers. Notably, the hm and K parameters of the plasticizers were thoroughly calculated for typical indoor interfaces, including airborne particles, settled dust, and impermeable and permeable materials. Overall, this study advances the understanding of indoor plasticizers, facilitating health-risk assessment and the development of suitable control and monitoring technologies.

Burning of municipal waste in household furnaces and the health of their owners

The aim of the study was to determine the scale of emission and airborne dispersion of selected pollutants (PM2.5, PM10, TVOC, HCHO) associated with the combustion of various types of municipal waste (MW), its mixed stream and separate fractions, in a household furnace, as compared to conventional (CF) and alternative (AF) fuels. We demonstrated that each type of fuel (AF, CF, AFw) combusted in a household furnace is a significant source of air pollutants, especially fine PM2.5 particles, whose concentrations exceeded the limit values (3.1-17.2 times for PM2.5 and 0.5-7.4 times for PM10). The combustion of MW in household furnaces generated higher levels of PM2.5 (up to 345 µg/m3) and PM10 (up to 369 µg/m3) than AF or CF, at the same time being a significant source of TVOC (up to 0.3 mg/m3) and HCHO (0.4 mg/m3). The analysis showed that according to the Polish and European classification, air quality (AQI) during the combustion of all the materials analyzed is very poor (n = 12) or extremely poor (n = 19). The combustion of such materials as polystyrene, rubber and upholstery foam in household furnaces generates drastically high health risk to local inhabitants. We found that the combustion of polystyrene generated the highest Cancer Risk (CR) values of 1.04E-01 (children) and 2.60E-02 (adults), exceeding the acceptable level multiple times (CR > 10-6). Inhalation exposure to very poor air quality can lead to health problems, such as disorders of the respiratory, cardiovascular and immune systems. Additional risk is posed by solid fuel combustion in rural areas, which may be a significant factor deteriorating the chemical condition of soils, especially those used for agricultural purposes.

Dataset on concentrations of volatile organic compounds in indoor environments of offices, educational and residential buildings in the European Union between 2010 and 2023

Indoor air pollutants, such as volatile organic compounds (VOCs), include a range of hazardous substances that can accumulate in the indoor environments. As individuals spend 80-90 % of their daily time indoors, chronic exposure to VOCs has been recognised as an important public health concern. Therefore, measuring the concentration of indoor air pollutants is essential for improving indoor air quality and thereby reducing the associated burden of disease. Our objective was to generate a dataset on concentrations of VOCs measured in offices and in educational and residential buildings in the member states of the European Union between 2010 and 2023. Data were collected by means of systematic literature searches, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search was carried out in the PubMed, Web of Science, and Scopus databases. In addition to data on VOC levels, information on types of buildings, seasons when the measurements were performed, heating and ventilation systems, humidity and temperature at the sampling points, and methods used for sampling and analysis was collected. The dataset contains information on 18 VOCs and total volatile organic compounds (TVOC) from 101 original research papers. It consists of 19 worksheets, each with 46 columns, and the number of rows varies depending on the number of articles per VOC/TVOC, ranging from 11 to 576 rows. This dataset will be of use to public health professionals interested in using systematically collected data on VOC levels and corresponding reference concentrations to estimate the health risks associated with exposure to VOCs.

Cleaning products: Their chemistry, effects on indoor air quality, and implications for human health

The use of cleaning and disinfecting products both at work and at home increased during the COVID-19 pandemic. Those products often include surfactants, acids/bases, carcinogens such as chloroform, and endocrine-disrupting chemicals, such as cyclosiloxanes, phthalates, and synthetic fragrances, which may cause harmful health effects among professional cleaners as well as among people exposed at home or in their workplaces. The aim of this study was to synthesize the effects of the commonly used chemical, surface cleaning and disinfecting products on indoor air quality, focusing on chemical and particulate matter pollutants, exposure, and human health in residential and public buildings. We also provide a summary of recommendations to avoid harmful exposure and suggest future research directions. PubMed, Google Scholar, Scopus, and Web of Science (WoS) were used to search the literature. Analysis of the literature revealed that the use of cleaning products and disinfectants increase occupants' exposure to a variety of harmful chemical air contaminants and to particulate matter. Occupational exposure to cleaning and disinfectant products has been linked to an increased risk of asthma and rhinitis. Residential exposure to cleaning products has been shown to have an adverse effect on respiratory health, particularly on asthma onset, and on the occurrence of asthma(-like) symptoms among children and adults. Efforts to reduce occupants' exposure to cleaning chemicals will require lowering the content of hazardous substances in cleaning products and improving ventilation during and after cleaning. Experimentally examined, best cleaning practices as well as careful selection of cleaning products can minimize the burden of harmful air pollutant exposure indoors. In addition, indirect ways to reduce exposure include increasing people's awareness of the harmfulness of cleaning chemicals and of safe cleaning practices, as well as clear labelling of cleaning and disinfecting products.

The impact of formaldehyde exposure on lung inflammatory disorders: Insights into asthma, bronchitis, and pulmonary fibrosis

Lung inflammatory disorders are a major global health burden, impacting millions of people and raising rates of morbidity and death across many demographic groups. An industrial chemical and common environmental contaminant, formaldehyde (FA) presents serious health concerns to the respiratory system, including the onset and aggravation of lung inflammatory disorders. Epidemiological studies have shown significant associations between FA exposure levels and the incidence and severity of several respiratory diseases. FA causes inflammation in the respiratory tract via immunological activation, oxidative stress, and airway remodelling, aggravating pre-existing pulmonary inflammation and compromising lung function. Additionally, FA functions as a respiratory sensitizer, causing allergic responses and hypersensitivity pneumonitis in sensitive people. Understanding the complicated processes behind formaldehyde-induced lung inflammation is critical for directing targeted strategies aimed at minimizing environmental exposures and alleviating the burden of formaldehyde-related lung illnesses on global respiratory health. This abstract explores the intricate relationship between FA exposure and lung inflammatory diseases, including asthma, bronchitis, allergic inflammation, lung injury and pulmonary fibrosis.

Wearing face masks as a potential source for inhalation and oral uptake of inanimate toxins - A scoping review

BACKGROUND

From 2020 to 2023 many people around the world were forced to wear masks for large proportions of the day based on mandates and laws. We aimed to study the potential of face masks for the content and release of inanimate toxins.

METHODS

A scoping review of 1003 studies was performed (database search in PubMed/MEDLINE, qualitative and quantitative evaluation).

RESULTS

24 studies were included (experimental time 17 min to 15 days) evaluating content and/or release in 631 masks (273 surgical, 228 textile and 130 N95 masks). Most studies (63%) showed alarming results with high micro- and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkyl substances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate, DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.

DISCUSSION

Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.

CONCLUSION

Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.

Bangkok school indoor air quality: monitoring and intervention by positive pressure fresh air system

A PM2.5 crisis in Thailand has caused the Thai government and public to be increasingly concerned about children's exposure to PM2.5 during time in school. This study is a part of a project to create a modeled effective school indoor air quality management for the Bangkok Metropolitan Administration (BMA). We measured air quality and environment in 10 Bangkok school rooms, including CO2, CO, O3, PM2.5, PM10, TVOCPID, formaldehyde, airborne bacteria and fungi, and gaseous organic contaminants. The indoor-to-outdoor concentration ratios indicated that either outdoor sources or indoor + outdoor sources were the predominant contributors to PM in naturally ventilated classrooms. Meanwhile, PM levels in air-conditioned classrooms strongly depended on class activities. CO2 measurements showed that the air-conditioned classrooms had a low 0.4 per hour air change rate and total fungal counts also reached 800 CFU m-3. Analysis of gaseous organic compounds showed that the two most abundant were aliphatic and aromatic hydrocarbons, accounting for 60% by mass concentration. Interestingly, 2-ethyl-1-hexanol, a mucous membrane irritant, was detected in all study rooms. In one naturally ventilated classroom, we implemented a positive pressure fresh air system to mitigate in-class PM levels; it kept PM levels below 20 μg m-3 throughout the class day. Students reported a 20-37% increase in satisfaction with the perceived indoor environmental quality and reported reduced rates in all symptoms of the sick building syndrome after implementing the positive pressure system.

The association between clustering based on composition of volatile organic compound in indoor air and building-related symptoms

Volatile organic compounds (VOCs) have been suspected to cause building-related symptoms (BRSs). Although some studies investigated the association between BRSs and VOCs in indoor air, those results were inconsistent. This study investigated the contamination status of VOCs in the indoor air of 154 houses in Japan. Additionally, these samples were grouped by hierarchical clustering analysis based on the VOC composition, and the relationship between a VOC cluster and the BRSs was investigated. The median concentration of the sum of VOCs (ΣVOCs) was 140 μg m-3 (range: 18-3500 μg m-3). The levels of acetaldehyde in four samples and p-dichlorobenzene in one sample exceeded the guideline value. As a result of the hierarchical clustering analysis, the samples in this study were divided into six characteristic clusters based on the VOC composition. The ΣVOCs in cluster 1 were significantly lower than those in other clusters. In cluster 2, acyclic and aromatic hydrocarbons were dominant. Cluster 3 had a relatively high proportion of limonene. In cluster 4, the concentrations and composition ratios of α-pinene were higher than those of other clusters. In cluster 5, p-dichlorobenzene accounted for 42 %-72 % of the total VOCs. Cluster 6 had a relatively high proportion of decamethyl cyclopentasiloxane. This clustering likely depended on the construction of houses and lifestyles. As a result of logistic regression analysis, cluster 5 was associated with the cough symptoms of the BRSs. The results of the present study suggest that investigating the association between VOCs and BRSs is necessary to consider not only total concentrations such as TVOC and ΣVOCs but also VOC composition.

The association of hemoglobin ethylene oxide levels with albuminuria in US adults: analysis of NHANES 2013-2016

Ethylene oxide (EO) is a common chemical contaminant in the environment and associated with the occurrence of multiple clinical diseases. This study aimed to explore the association of hemoglobin ethylene oxide (HbEO) levels with the risk of albuminuria in a representative sample of US adults. In total, 3523 participants from National Health and Nutrition Examination Survey (NHANES) 2013-2016 were enrolled and classified into four groups based on HbEO. Restricted cubic spline plots and multiple logistic regression were performed to investigate the connection between HbEO levels and albuminuria, and mediation analysis was applied to elucidate the potential mechanism for the effect of HbEO concentrations on albuminuria. In the results, compared with the extreme quartile of HbEO levels, the weighted prevalence of albuminuria was significantly increased in participants with highest quartile (Q4 vs Q1, 11.2% vs 8.1%). Restricted cubic spline plots revealed that the risk of albuminuria raised non-linearly and positively with elevated HbEO level. After adjusting for confounders, the logistic regression suggested that the risk of albuminuria was enhanced by 12% for each one-unit increase in log-2-transformed HbEO (OR = 1.12, 95% CI, 1.03-1.22, P = 0.007). Moreover, the multivariate ORs (95% CIs) on albuminuria was increased across the increasing HbEO quartiles (Q4 vs Q1, OR = 1.54, 95% CI, 1.09-2.17; P for trend = 0.029). Furthermore, the impact of high HbEO level on albuminuria was partially related to inflammation markers, including white blood cells (17.2%), neutrophils (22.1%), and lymphocytes (19.5%). To sum up, our study identified that high HbEO levels increased the risk of albuminuria in representative population of US adults, and several inflammatory mediators might be potentially involved in EO-associated albuminuria.

Carbon monoxide as an indicator of indoor air quality

Carbon monoxide is a priority pollutant that is suitable as an indicator for assessing indoor air quality. Monitoring should preferably be embedded in an intelligent network of different sensors.

Exposure hazards of particles and volatile organic compounds emitted from material extrusion 3D printing: Consolidation of chamber study data

Ultrafine particles and volatile organic compounds (VOCs) have been detected from material extrusion 3D printing, which is widely used in non-industrial environments. This study consolidates data of 447 particle emission and 58 VOC emission evaluations from a chamber study using a standardized testing method with various 3D printing scenarios. The interquartile ranges of the observed emission rates were 109-1011 #/h for particles and 0.2-1.0 mg/h for total VOC. Print material contributed largely to the variations of particle and total VOC emissions and determined the most abundantly emitted VOCs. Printing conditions and filament specifications, included printer brand, print temperature and speed, build plate heating setup, filament brand, color and composite, also affected emissions and resulted in large variations observed in emission profiles. Multiple regression showed that particle emissions were more impacted by various print conditions than VOC emissions. According to indoor exposure modeling, personal and residential exposure scenarios were more likely to result in high exposure levels, often exceeding recommended exposure limits. Hazardous VOCs commonly emitted from 3D printing included aromatics, aldehydes, alcohols, ketones, esters and siloxanes, among which were various carcinogens, irritants and developmental and reproductive toxins. Therefore, 3D printing emits a complex mixture of ultrafine particles and various hazardous chemicals, exposure to which may exceed recommended exposure limits and potentially induce acute, chronic, or developmental health effects for users depending on exposure scenarios.

Measuring the quantity of harmful volatile organic compounds inhaled through masks

An increase in the concentration of environmental particulate matter and the spread of the COVID-19 virus have dramatically increased our time spent wearing masks. If harmful chemicals are released from these masks, there may be harmful effects on human health. In this study, the concentration of volatile organic compounds (VOCs) emitted from some commonly used masks was assessed qualitatively and quantitatively under diverse conditions (including different mask material types, time between opening the product and wearing, and mask temperature). In KF94 masks, 1-methoxy-2-propanol (221 ± 356 µg m-3), N,N-dimethylacetamide (601 ± 450 µg m-3), n-hexane (268 ± 349 µg m-3), and 2-butanone (160 ± 244 µg m-3) were detected at concentrations 22.9-147 times higher than those found in masks made from other materials, such as cotton and other functional fabrics. In addition, in KF94 masks, the total VOC (TVOC) released amounted to 3730 ± 1331 µg m-3, about 14 times more than that released by the cotton masks (267.5 ± 51.6 µg m-3). In some KF94 masks, TVOC concentration reached over 4000 µg m-3, posing a risk to human health (based on indoor air quality guidelines established by the German Environment Agency). Notably, 30 min after KF94 masks were removed from their packaging, TVOC concentrations decreased by about 80% from their initial levels to 724 ± 5.86 µg m-3; furthermore, 6 h after removal, TVOC concentrations were found to be less than 200 µg m-3. When the temperature of the KF94 masks was raised to 40 oC, TVOC concentrations increased by 119-299%. Since the types and concentrations of VOCs that will be inhaled by mask wearers vary depending on the mask use conditions, it is necessary to comply with safe mask wearing conditions.

Is indoor environment a risk factor of building-related symptoms?

The indoor environment, particularly indoor air quality (IAQ), is significantly associated with building-related symptoms (BRSs) in humans. In our previous studies, we demonstrated a significant relationship between BRSs and indoor chemical concentrations. In Japan, the Ministry of Health, Labor, and Welfare (MHLW) guideline recommends an air quality target of 13 volatile organic compounds (VOCs) and a provisional target of 400 μg/m3 for total VOCs (TVOC). The objective of this study was to determine the relationship between TVOC levels and the risk of BRSs using the Japanese provisional target TVOC level of 400 μg/m3. The relationship between odor intensity and BRSs while the TVOC levels were under 400 μg/m3 was also examined. The study was conducted in a laboratory house (LH) on the campus of Chiba University from 2017-2019. The study included 149 participants who spent 60 minutes in the LH. The participants were asked to evaluate the IAQ of the LH. A significant relationship between the risk of BRSs and the provisional target TVOC level was observed (odds ratio: 2.94, 95% confidence interval: 1.18-7.35). Furthermore, a significant relationship between odor intensity and risk of BRSs in spaces with TVOC levels less than 400 μg/m3 was detected (odds ratio: 6.06, 95% confidence interval: 1.21-30.44). In conclusion, the risk of BRSs is significantly lower in spaces with low TVOC levels and low odor intensity. Reducing the concentration of airborne chemicals and odor intensity may improve IAQ and prevent BRSs.

Quantum chemical calculation of the vapor pressure of volatile and semi volatile organic compounds

The vapor pressure is a specific and temperature-dependent parameter that describes the volatility of a substance and thus its driving force for evaporation or sublimation into the gas phase. Depending on the magnitude of the vapor pressure, there are different methods for experimental determination. However, these are usually associated with a corresponding amount of effort and become less accurate as the vapor pressure decreases. For purposes of vapor pressure prediction, algorithms were developed that are usually based on quantitative structure-activity relationships (QSAR). The quantum mechanical (QM) approach followed here applies an alternative, much less empirical strategy, where the change in Gibbs free energy for the transition from the condensed to the gas phase is obtained from conformer ensembles computed for each phase separately. The results of this automatic, so-called CRENSO workflow are compared with experimentally determined vapor pressures for a large set of environmentally relevant compounds. In addition, comparisons are made with the single structure-based COSMO-RS QM approach, linear-free-energy relationships (LFER) as well as results from the SPARC program. We show that our CRENSO workflow is superior to conventional prediction models and provides reliable vapor pressures for liquids and sub-cooled liquids over a wide pressure range.