Quantitative assessments of indoor air pollution and respiratory health in a population-based sample of French dwellings

Metal-organic frameworks (MOFs): A review of volatile organic compounds (VOCs) detection

This research presents a systematic review of the application of metal-organic frameworks (MOFs) to detect volatile organic compounds (VOCs). VOCs, compounds with high vapor pressure at ambient temperature and normal pressure, are widely present in a variety of industrial and living environments. VOCs are not only hazardous to the environment but also have a severe impact on human health. Therefore, an excellent research interest is developing efficient and sensitive detection technologies for VOCs. In this article, we first introduce the definition and classification of VOCs and their sources and discuss the environmental and health hazards of VOCs. Then, the discussion focuses on various sensors based on MOFs, including electrochemical sensors, fluorescence sensors, colorimetric sensors, and surface-enhanced Raman spectroscopy (SERS) sensors. In electrochemical detection, MOFs, as sensing materials, exhibit good detection performance due to their ultra-large surface area and highly adjustable pore size structure. In fluorescence detection, MOFs achieve high sensitivity and selective detection of VOCs under their unique optical properties. Colorimetric sensors, on the other hand, achieve the detection of VOCs through color change, which has the advantages of low cost and easy operation. In contrast, SERS sensors utilize the high surface area of MOFs and specific Raman enhancement effect to achieve ultra-high sensitivity detection of VOCs, which is especially suitable for trace analysis. Immediately after that, we describe the research progress of various sensors for VOCs detection and analyze their detection mechanisms and application prospects. Finally, the MOFs-based VOCs detection technology is summarized, and the current challenges and future development directions are pointed out.

Volatile organic compounds release from carbonized solid fuels derived from municipal solid waste: Risks, mitigation, and regulatory challenges

With the global population surpassing 8 billion in 2022 and projected to exceed 10 billion by 2058, municipal solid waste (MSW) generation presents a formidable challenge. One approach to manage MSW is Waste-to-Energy. This includes the conversion of MSW into carbonized solid fuel (CSF) through thermochemical processes. However, concerns regarding volatile organic compounds (VOCs) release from CSF during storage and use have arisen. Such release can pose potential health and environmental risks, yet the issue remains underexplored. This review critically evaluates VOC release from waste-derived CSF, namely carbonized refuse-derived fuel. It focuses on gaps in existing research, inconsistencies in VOC quantification methods, and regulatory challenges. Unlike existing studies that primarily examine process emissions, this review emphasizes the release of VOCs during storage and handling. A framework to integrate process-condition modeling and post-production release assessment was proposed to provide insights into mitigation strategies for VOC release reduction during storage and handling. Our findings highlight critical research gaps in VOC characterization, predictive modeling, and long-term exposure risks. This review emphasizes the need for standardized methodologies and stricter regulatory oversight in the management of waste-derived solid fuels.

Formaldehyde and asthma: a plausibility?

Formaldehyde (FA) is a ubiquitous indoor air pollutant emitted from construction, consumer, and combustion-related products, and ozone-initiated reactions with reactive organic volatiles. The derivation of an indoor air quality guideline for FA by World Health Organization in 2010 did not find convincing evidence for bronchoconstriction-related reactions as detrimental lung function. Causal relationship between FA and asthma has since been advocated in meta-analyses of selected observational studies. In this review, findings from controlled human and animal exposure studies of the airways, data of FA retention in the respiratory tract, and observational studies of reported asthma applied in meta-analyses are analyzed together for coherence of direct association between FA and asthma. New information from both human and animal exposure studies are evaluated together with existing literature and assessed across findings from observational studies and associated meta-analyses thereof. Retention of FA in the upper airways is > 90% in agreement with mice exposure studies that only extreme FA concentrations can surpass trachea, travel to the lower airways, and cause mild bronchoconstriction. However, taken together, detrimental lung function effects in controlled human exposure studies have not been observed, even at FA concentrations up 4 ppm (5 mg/m3), and in agreement with controlled mice exposure studies. Typical indoor FA concentrations in public buildings and homes are far below a threshold for sensory irritation in the upper airways, based on controlled human exposure studies, to induce sensory-irritative sensitization nor inflammatory epithelial damage in the airways. Analysis of the observational heterogeneous studies applied in the meta-analyses suffers from several concomitant multifactorial co-exposures, which invalidates a direct association with asthma, thus the outcome of meta-analyses. The evidence of a direct causal relationship between FA and asthma is insufficient from an experimental viewpoint that includes retention data in the upper airways and controlled animal and human exposure studies. Taken together, a coherence of controlled experimental findings with individual observational studies and associated meta-analyses, which suffer from caveats, is absent. Further, lack of identified evidence of FA-IgE sensitization in both experimental studies and observational studies agrees with indoor FA concentrations far below threshold for sensory irritation. The assessment of experimental data with uncontrolled observational studies in meta-analyses is incompatible with a direct causal relationship between FA and asthma or exacerbation thereof due to lack of coherence and plausibility.

Household cleaning agents impact on pediatric asthma: a systematic review and meta-analysis

BACKGROUND

Household cleaning agents promote hygiene along with causing respiratory effects, especially pediatric asthma. This systematic review quantified the association between exposure to household cleaning agents and pediatric asthma.

METHOD

Five databases were searched. Data were analyzed qualitatively and quantitatively. RevMan 5.4 calculated odds ratios (OR) with 95% confidence intervals (CI), and a funnel plot assessed publication bias. The Mixed Methods Appraisal Tool (MMAT) and GRADE framework assessed methodological quality and certainty respectively.

RESULTS

Sixteen studies met the eligibility criteria. Meta-analysis showed a significant association between the use of household cleaning agents and pediatric asthma (OR 2.90 (95% CI: 2.13-3.95; p < 0.01, I2 = 98%). Exposure stages also showed significant (p < 0.01) association with household cleaning agents (OR 2.92 (95% CI: 2.12-4.03, I2 = 98%). No publication bias or high risk of bias was found.

CONCLUSION

A strong association between exposure to household cleaning agents and an increased risk of pediatric asthma was found. .

Residential Proximity Land Use Characteristics and Exhaled Volatile Organic Compounds' Impact on Pulmonary Function in Asthmatic Children

BACKGROUND

Urban air pollution adversely affects children's respiratory systems, but the impact of volatile organic compounds (VOCs) on children's pulmonary function remains unclear. This study aims to identify exhaled VOCs linked to land use characteristics and reduced pulmonary function in asthmatic children, as well as to explore environmental thresholds influencing VOC exposure levels.

METHODS

We enrolled 97 asthmatic children, aged 7 to 20, from Changhua County, Taiwan, and collected personal and residential data, collected exhaled VOC samples, and conducted pulmonary function tests. Land use characteristics were derived from the children's residential addresses. This study used two models to explore the relationships between land use, VOC levels, and pulmonary function.

RESULTS

Our results show that m/p-xylene, 1,3,5-trimethylbenzene, and 1,2,4-trimethylbenzene were key contributors to FEV1/FVC and significantly predicted FEV1/FVC < 90% (AUC = 0.66; 95% CI: 0.53 to 0.79). These VOCs were also linked to major road areas within a 300 m buffer around children's homes.

CONCLUSIONS

This study fills a research gap on low-level outdoor VOC exposure and pediatric respiratory health, examining 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, and m/p-xylene as potential biomarkers for impaired pulmonary function in children.

Health Risks of Asphalt Emission: State-of-the-Art Advances and Research Gaps

Asphalt-related emissions pose significant health risks due to the release of volatile organic compounds (VOCs) that affect both workers in construction and the general public. Even at low concentrations, certain VOCs are highly toxic, with some of their metabolic byproducts, such as epoxides, known to cause DNA damage, oxidative stress, and other genetic alterations. The health implications are particularly concerning given that these emissions are persistent, and exposure can occur over prolonged periods, especially in urban areas where asphalt is prevalent. However, despite growing awareness, there remain significant gaps in our understanding of the long-term effects of chronic, low-level exposure to asphalt VOCs. Research to date has largely focused on acute exposure effects, particularly in occupational settings, leaving much unknown about the broader impact on the general public, especially vulnerable groups like children and the elderly. Moreover, the complex interactions between asphalt-derived VOCs and other environmental pollutants are not well understood, further complicating our understanding of their cumulative health impact. This paper provides a comprehensive overview of the current research landscape, starting with a discussion of the health risks associated with asphalt VOCs, supported by key findings from recent studies. It then explores the latest technological advancements in VOC detection, characterization, and monitoring, and identifies critical gaps in existing research.

Integrating Real-Time Air Quality Monitoring, Ecological Momentary Assessment, and Spirometry to Evaluate Asthma Symptoms: Usability Study

BACKGROUND

Individuals are exposed to a variety of indoor residential toxins including volatile organic compounds and particulates. In adults with asthma, such exposures are associated with asthma symptoms, asthma exacerbations, and decreased lung function. However, data on these exposures and asthma-related outcomes are generally collected at different times and not in real time. The integration of multiple platforms to collect real-time data on environmental exposure, asthma symptoms, and lung function has rarely been explored.

OBJECTIVE

This paper describes how adults with asthma perceive the acceptability and usability of three integrated devices: (1) residential indoor air quality monitor, (2) ecological momentary assessment (EMA) surveys delivered via a smartphone app, and (3) home spirometry, over 14 days.

METHODS

Participants (N=40) with uncontrolled asthma were mailed the Awair Omni indoor air quality monitor, ZEPHYRx home spirometer, and detailed instructions required for the in-home monitoring. The air quality monitor, spirometer, and EMA app were set up and tested during a videoconference or phone orientation with a research team member. Midway through the 14-day data collection period, participants completed an interview about the acceptability of the study devices or apps, instructional materials provided, and the setup process. At the end of the 14-day data collection period, participants completed a modified System Usability Scale. A random sample of 20 participants also completed a phone interview regarding the acceptability of the study and the impact of the study on their asthma.

RESULTS

Participants ranged in age from 26 to 77 (mean 45, SD 13.5) years and were primarily female (n=36, 90%), White (n=26, 67%), college graduates (n=25, 66%), and residing in a single-family home (n=30, 75%). Most indicated that the air quality monitor (n=23, 58%), the EMA (n=20, 50%), and the spirometer (n=17, 43%) were easy to set up and use. Challenges with the EMA included repetitive surveys, surveys arriving during the night, and technical issues. While the home spirometer was identified as a plausible means to evaluate lung function in real time, the interpretation of the readings was unclear, and several participants reported side effects from home spirometer use. Overall, the acceptability of the study and the System Usability Scale scores were high.

CONCLUSIONS

The study devices were highly acceptable and usable. Participant feedback was instrumental in identifying technical challenges that should be addressed in future studies.

Exposure to volatile organic compounds and growth indicators in adolescents: Unveiling the association and potential intervention strategies

Environmental pollutant is considered to be one of the important factors affecting adolescent growth. However, the effects of volatile organic compounds (VOCs) exposure on adolescent growth have not been assessed. Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 was used to examine the associations between VOCs exposure and adolescent growth indicators through three statistical models. The mediating effect of bone mineral density (BMD) on these associations was examined. The potential pathways and key targets were identified by the network pharmacology analysis methods. This study included 746 adolescents. Three statistical methods consistently showed a negative correlation between VOCs exposure and adolescent growth indicators. Furthermore, BMD mediated the relationship between VOCs exposure and adolescent growth indicators, with mediated proportion ranging from 4.3 % to 53.4 %. Network pharmacology analysis found a significant enrichment in IL-17 signaling pathway. Moreover, the adverse effects of VOCs exposure on adolescent growth were observed to significantly attenuate in adolescents with high serum vitamin D levels. Our results suggested that VOCs exposure was an adverse factor affecting adolescent growth, with BMD playing a significant regulatory role, and IL-17 signaling pathway was the underlying mechanism. Vitamin D supplementation may be a viable strategy to prevent VOCs exposure from affecting adolescent growth.

Breathing Uneasily: Employees' Stories of Coping With Poor Indoor Air Quality in the Workplace

OBJECTIVES

This phenomenological study aimed to elucidate the lived experiences of employees suffering from poor indoor air quality (IAQ) in their university workplace. It addresses gaps in understanding IAQ's personal impacts from occupants' perspectives.

BACKGROUND

Prior research on sick building syndrome and indoor air pollution utilized quantitative methods to assess physical health outcomes. However, few studies have adopted qualitative approaches to uncover the meanings ascribed to adverse IAQ experiences and their influences on psychosocial well-being.

METHODS

In-depth semi-structured interviews were conducted with five university employees who attributed their chronic illnesses to poor IAQ in their 60-year-old office building with a history of IAQ concerns. Verbatim transcripts were analyzed using qualitative techniques including thematic coding to extract key themes conveying shared experiences.

RESULTS

Employees depicted the building itself as fundamentally "sick" and stigmatized, compelling complex coping behaviors hindering productivity. Communication breakdowns, mistrust in leadership, and strained workplace relationships were prevalent. A sense of betrayal, powerlessness, and a sense of detachment from the workplace emerged with home as a refuge.

CONCLUSIONS

Although technically adequate, poor IAQ profoundly damaged perceived health, quality of life, relationships, and satisfaction. The accounts emphasize IAQ's psychosocial dimensions, advancing theoretical links between indoor environments and well-being. Supportive policies, transparency, communication, participatory processes, and human-centered strategies emerge as ways to nurture productivity, well-being, and organizational health.

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 asthma and air pollution: Evidence from India

In the last two decades, air pollution has increased throughout India resulting in the deterioration of air quality. This paper estimates the prevalence of self-reported asthma in women aged 15-49 years and examines the link between outdoor air pollution and disease prevalence in India by combining satellite data on particulate matter (PM2.5) and the National Family Health Survey (NFHS-4), 2015-16. The results indicate that both indoor pollution as well as outdoor air pollution are important risk factors for asthma in women as both independently increase the probability of asthma among this group. Strategies around the prevention of asthma need to recognize the role of both indoor as well as outdoor air pollution. The other significant risk factors for asthma are smoking, second-hand smoking, type of diet and obesity.

The Association between Maternal Urinary Phthalate Concentrations and Blood Pressure in Pregnancy: A Systematic Review and Meta-Analysis

Phthalates are commonly found in a wide range of environments and have been linked to several negative health outcomes. While earlier research indicated a potential connection between phthalate exposure and blood pressure (BP) during pregnancy, the results of these studies remain inconclusive. The objective of this meta-analysis was to elucidate the relationship between phthalate exposure and BP in pregnancy. A comprehensive literature search was carried out with PubMed, EMBASE, and Web of Science, and pertinent studies published up until 5 March 2023 were reviewed. Random-effects models were utilized to consolidate the findings of continuous outcomes, such as diastolic and systolic BP, as well as the binary outcomes of hypertensive disorders of pregnancy (HDP). The present study included a total of 10 studies. First-trimester MBP exposure exhibited a positive association with mean systolic and diastolic BP during both the second and third trimesters (β = 1.05, 95% CI: 0.27, 1.83, I² = 93%; β = 0.40, 95% CI: 0.05, 0.74, I² = 71%, respectively). Second-trimester monobenzyl phthalate (MBzP) exposure was positively associated with systolic and diastolic BP in the third trimester (β = 0.57, 95% CI: 0.01, 1.13, I² = 0; β = 0.70, 95% CI: 0.27, 1.13, I² = 0, respectively). Conversely, first-trimester mono-2-ethylhexyl phthalate (MEHP) exposure demonstrated a negative association with mean systolic and diastolic BP during the second and third trimesters (β = -0.32, 95% CI: -0.60, -0.05, I² = 0; β = -0.32, 95% CI: -0.60, -0.05, I² = 0, respectively). Additionally, monoethyl phthalate (MEP) exposure was found to be associated with an increased risk of HDP (OR = 1.12, 95% CI: 1.02, 1.23, I² = 26%). Our study found that several phthalate metabolites were associated with increased systolic and diastolic BP, as well as the risk of HDP across pregnancies. Nevertheless, given the limited number of studies analyzed, additional research is essential to corroborate these findings and elucidate the molecular mechanisms linking phthalates to BP changes during pregnancy.

Associations between the compositional patterns of blood volatile organic compounds and chronic respiratory diseases and ages at onset in NHANES 2003-2012

BACKGROUND

and Purpose Volatile organic compounds (VOCs) pose a serious respiratory hazard. This study evaluated the relationship between the compositional patterns of blood VOCs and the risk and age at onset of chronic respiratory diseases (CRDs), including asthma, emphysema and chronic bronchitis, with the objective of preventing or delaying CRDs.

METHODS

Participants from five cycles of the NHANES survey were included. Blood VOCs were clustered using k-means clustering. Differences in VOCs and age at onset between multiple groups were compared with the Kruskal‒Wallis test. Logistic regression and a generalized linear model were applied to examine the associations between different compositional patterns of blood VOCs and risk and age at onset of CRDs.

RESULTS

12,386 participants were enrolled in this study. Three VOC compositional patterns were identified after clustering nine species of blood VOCs. The concentration of VOCs in pattern 2 was relatively low and stable. The concentrations of benzene, ethylbenzene, o-xylene, styrene, toluene and m-p-xylene in pattern 3 and the concentrations of 1,4-dichlorobenzene and MTBE in pattern 1 were significantly higher than those in pattern 2. After adjustment for covariates, the participants with VOC pattern 3 had an increased risk of asthma (OR = 1.23, 95% CI: 1.02, 1.49), emphysema (OR = 3.37, 95% CI: 2.24, 5.06) and chronic bronchitis (OR = 1.79, 95% CI: 1.30, 2.45). Meanwhile, VOC pattern 3 was negatively correlated with the age at onset of asthma (β = -5.61, 95% CI: 9.69, -1.52) and chronic bronchitis (β = -9.17, 95% CI: 13.96, -4.39). VOC pattern 1 was not associated with either risk or age at onset of the three CRDs after adjustment.

CONCLUSIONS

Changing the compositional pattern of blood VOCs by reducing certain species of VOCs may be a new strategy to lengthen the ages at onset of CRDs and effectively prevent them.

Volatile organic compounds (VOC) in homes associated with asthma and lung function among adults in Northern Europe

Associations between measured specific VOC reported to be associated with dampness and microbial growth in dwellings and asthma, lung function were investigated in 159 adults (one adult/home) from three North European cities (Reykjavik, Uppsala and Tartu). Spirometry was performed and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and FEV₁/FVC were measured. Among 159 participants, 58% were females, 24.5% atopics, 25.8% current smokers and 41% reported dampness or mold at home. Dimethyl disulphide (p = 0.004), ethyl isobutyrate (p = 0.021) and ethyl 2-methylbutyrate (p = 0.035) were associated with asthma. Isobutanol (p = 0.043), 3-methyl-1-butanol (p = 0.020), 2-hexanone (p = 0.033), 1-octen-3-ol (p = 0.027), 2-methyl-1-butanol (p = 0.022) and 2-ethyl-1-hexanol (p = 0.045) were associated with lower FEV₁. Isobutanol (p = 0.004), 3-methyl-1-butanol (p = 0.001), 2-heptanone (p = 0.047) and 2-methyl-1-butanol (p = 0.002) were associated with lower FEV₁/FVC. The association between dimethyl disulphide and asthma was more pronounced in females (p for interaction 0.099). The association between 1-butanol and lower FEV₁ was more pronounced in males (p for interaction 0.046). The associations between 3-octanone (p for interaction 0.064), 2-ethyl-1-hexanol (p for interaction 0.049) and lower FEV₁, and between 2-heptanone (p for interaction 0.021), 3-octanone (p for interaction 0.008) and lower FEV₁/FVC were stronger in homes with dampness/mold. Factor analysis identified one VOC factor related to asthma and two VOC factors related to lower lung function. Increased air concentrations of 2-heptanone, ethyl 2-methylbutyrate and ethyl isobutyrate were related to prescence of certain mold species (Aspergillus sp., Cladosporum sp. and Penicillium sp.) or building dampness. Some VOC were associated with type of dwelling, building age and pet keeping. In conclusion, some VOC reported to be associated with dampness and microbial growth can be associated with asthma and lower lung function in adults. Associations between these VOC and respiratory illness can be stronger in homes with dampness/mold. There can be gender differences in respiratory health effects when exposed to indoor VOC.

Indoor air pollution and human ocular diseases: Associated contaminants and underlying pathological mechanisms

People spend a long time indoors, especially young children. The risk of indoor pollution on human health is one of the current hotspots in environmental and public health. The human ocular surface is highly susceptible to indoor environment quality. Epidemiological data have linked human ophthalmological disorders with exposure to indoor pollution. In this review, we summarized the adverse impacts of indoor pollution on the human ocular surface. Several studies demonstrated that indoor contaminants including particulate matter, volatile/semi-volatile organic compounds, heavy metals, and fuel combustion and cigarette smoke exposure were associated with the incidence of human dry eye, conjunctivitis, glaucoma, cataracts, age-related macular degeneration, and keratitis. In addition, toxicological investigations revealed that indoor pollution-induced induced chronic inflammation, oxidative damage, and disruption of tight junctions are the main underlying pathological mechanisms for ocular surface diseases. Taken together, this review may expand the understanding of pollution-induced eye disorder and highlight the importance of reducing associated contaminants to decrease their detrimental effects on human eyes.

Sampling Volatile Organic Compound Emissions from Consumer Products: A Review

Volatile organic compounds (VOCs) are common constituents of many consumer products. Although many VOCs are generally considered harmless at low concentrations, some compound classes represent substances of concern in relation to human (inhalation) exposure and can elicit adverse health effects, especially when concentrations build up, such as in indoor settings. Determining VOC emissions from consumer products, such as toys, utensils or decorative articles, is of utmost importance to enable the assessment of inhalation exposure under real-world scenarios with respect to consumer safety. Due to the diverse sizes and shapes of such products, as well as their differing uses, a one-size-fits-all approach for measuring VOC emissions is not possible, thus, sampling procedures must be chosen carefully to best suit the sample under investigation. This review outlines the different sampling approaches for characterizing VOC emissions from consumer products, including headspace and emission test chamber methods. The advantages and disadvantages of each sampling technique are discussed in relation to their time and cost efficiency, as well as their suitability to realistically assess VOC inhalation exposures.

Early-Stage Emissions of Formaldehyde and Volatile Organic Compounds from Building Materials: Model Development, Evaluation, and Applications

Emissions of formaldehyde and volatile organic compounds (VOCs) from building materials may result in poor indoor air quality. The emission process can be divided into three stages over time: early, transition, and equilibrium stages. In existing studies, mass transfer models without distinguishing the early and transition stages have been widely used for characterizing the formaldehyde/VOC emissions, with three key parameters involved in these models. Many methods have been proposed for determining these parameters by fitting the corresponding models to experimental data. However, multiple groups of best-fit parameters might coexist if experimental data are obtained at the early stage (to shorten the experimental time). Therefore, we developed a novel mass transfer model to describe the early-stage emissions by assuming the building material as semi-infinite medium. The novel model indicated that the early-stage emission was governed by only two parameters, instead of three parameters, which explained the reason for the multi-solution problem of existing methods. Subsequently, the application condition of the early-stage model was clarified, showing that the early stage was very common in the emissions of formaldehyde/VOCs. Finally, a novel approach for characterizing the emissions of formaldehyde/VOCs from building materials was proposed to eliminate the negative effects of the multi-solution problem.

Chemicals in European residences - Part I: A review of emissions, concentrations and health effects of volatile organic compounds (VOCs)

One of the more important classes of potentially toxic indoor air chemicals are the Volatile Organic Compounds (VOCs). However, due to a limited understanding of the relationships between indoor concentrations of individual VOCs and health outcomes, there are currently no universal health-based guideline values for VOCs within Europe including the UK. In this study, a systematic search was conducted designed to capture evidence on concentrations, emissions from indoor sources, and health effects for VOCs measured in European residences. We identified 65 individual VOCs, and the most commonly measured were aromatic hydrocarbons (14 chemicals), alkane hydrocarbons (9), aldehydes (8), aliphatic hydrocarbons (5), terpenes (6), chlorinated hydrocarbons (4), glycol and glycol ethers (3) and esters (2). The pathway of interest was inhalation and 8 individual aromatic hydrocarbons, 7 alkanes and 6 aldehydes were associated with respiratory health effects. Members of the chlorinated hydrocarbon family were associated with cardiovascular neurological and carcinogenic health effects and some were irritants as were esters and terpenes. Eight individual aromatic hydrocarbons, 7 alkanes and 6 aldehydes identified in European residences were associated with respiratory health effects. Of the 65 individual VOCs, 52 were from sources associated with building and construction materials (e.g. brick, wood products, adhesives and materials for flooring installation etc.), 41 were linked with consumer products (passive, electric and combustible air fresheners, hair sprays, deodorants) and 9 VOCs were associated with space heating, which may reflect the relatively small number of studies discussing emissions from this category of sources. A clear decrease in concentrations of formaldehyde was observed over the last few years, whilst acetone was found to be one of the most abundant but underreported species. A new approach based on the operational indoor air quality surveillance will both reveal trends in known VOCs and identify new compounds.

Utilizing Real-time Technology to Assess the Impact of Home Environmental Exposures on Asthma Symptoms: Protocol for an Observational Pilot Study

BACKGROUND

It is estimated that over 60% of adults with asthma have uncontrolled symptoms, representing a substantial health and economic impact. The effects of the home environment and exposure to volatile organic compounds (VOCs) and fine particulate matter (PM2.5) on adults with asthma remain unknown. In addition, methods currently used to assess the home environment do not capture real-time data on potentially modifiable environmental exposures or their effect on asthma symptoms.

OBJECTIVE

The aims of this study are to (1) determine the feasibility and usability of ecological momentary assessment (EMA) to assess self-report residential environmental exposures and asthma symptoms, home monitoring of objective environmental exposures (total VOCs and PM2.5), and lung function in terms of forced expiratory volume in 1 second (FEV1%); (2) assess the frequency and level of residential environmental exposures (eg, disinfectants/cleaners, secondhand smoke) via self-reported data and home monitoring objective measures; (3) assess the level of asthma control as indicated by self-reported asthma symptoms and lung function; and (4) explore associations of self-reported and objective measures of residential environmental exposures with self-reported and objective measures of asthma control.

METHODS

We will recruit 50 adults with asthma who have completed our online Global COVID-19 Asthma Study, indicated willingness to be contacted for future studies, reported high use of disinfectant/cleaning products, and have asthma that is not well controlled. Participants will receive an indoor air quality monitor and a home spirometer to measure VOCs, PM2.5, and FEV1%, respectively. EMA data will be collected using a personal smartphone and EMA software platform. Participants will be sent scheduled and random EMA notifications to assess asthma symptoms, environmental exposures, lung function, and mitigation strategies. After the 14-day data collection period, participants will respond to survey items related to acceptability, appropriateness, and feasibility.

RESULTS

This study was funded in March 2021. We pilot tested our procedures and began recruitment in April 2022. The anticipated completion of the study is 2023.

CONCLUSIONS

Findings from this feasibility study will support a powered study to address the impact of home environmental exposures on asthma symptoms and develop tailored, home-based asthma interventions that are responsive to the changing home environment and home routines.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05224076; https://clinicaltrials.gov/ct2/show/NCT05224076.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39887.

A review of practical statistical methods used in epidemiological studies to estimate the health effects of multi-pollutant mixture

Environmental risk factors have been implicated in adverse health effects. Previous epidemiological studies on environmental risk factors mainly analyzed the impact of single pollutant exposure on health, while in fact, humans are constantly exposed to a complex mixture consisted of multiple pollutants/chemicals. In recent years, environmental epidemiologists have sought to assess adverse health effects of exposure to multi-pollutant mixtures based on the diversity of real-world environmental pollutants. However, the statistical challenges are considerable, for instance, multicollinearity and interaction among components of the mixture complicate the statistical analysis. There is currently no consensus on appropriate statistical methods. Here we summarized the practical statistical methods used in environmental epidemiology to estimate health effects of exposure to multi-pollutant mixture, such as Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS) regressions, shrinkage methods (least absolute shrinkage and selection operator, elastic network model, adaptive elastic-net model, and principal component analysis), environment-wide association study (EWAS), etc. We sought to review these statistical methods and determine the application conditions, strengths, weaknesses, and result interpretability of each method, providing crucial insight and assistance for addressing epidemiological statistical issues regarding health effects from multi-pollutant mixture.

Influence of Home Indoor Dampness Exposure on Volatile Organic Compounds in Exhaled Breath of Mothers and Their Infants: The NELA Birth Cohort

Currently, the effect of exposure to indoor air contaminants and the presence of dampness at home on respiratory/atopic health is of particular concern to physicians. The measurement of volatile organic compounds (VOCs) in exhaled breath is a useful approach for monitoring environmental exposures. A great advantage of this strategy is that it allows the study of the impact of pollutants on the metabolism through a non-invasive method. In this paper, the levels of nine VOCs (acetone, isoprene, toluene, p/m-xylene, o-xylene, styrene, benzaldehyde, naphthalene, and 2-ethyl-1-hexanol) in the exhaled breath of subjects exposed and not exposed to home dampness were assessed. Exhaled breath samples were collected from 337 mother–child pairs of a birth cohort and analysed by gas-chromatography–mass-spectrometry. It was observed that the levels of 2-ethyl-1-hexanol in the exhaled breath of the mothers were significantly influenced by exposure to household humidity. In the case of the infants, differences in some of the VOC levels related to home dampness exposure; however, they did not reach statistical significance. In addition, it was also found that the eosinophil counts of the mothers exposed to home dampness were significantly elevated compared to those of the non-exposed mothers. To our knowledge, these findings show, for the first time, that exposure to home dampness may influence VOC patterns in exhaled breath.

Decomposition of VOCs using serial surface dielectric barrier discharge reactors

Decomposition of two typical volatile organic compounds (VOCs): toluene and methyl ethyl ketone (MEK), was investigated by introducing the complete energy yield (i.e. amount of VOCs totally converted to CO and CO₂ for every 1 kWh of electrical usage) and specific energy density (SED) for the non-thermal plasma technology. Three dielectric barrier discharge reactors of which SED range was 55 J/L to 283 J/L at a flow rate of 1 L/min were connected in a 3-reactor arranged in series using interconnecting tubes in the inlets and outlets. As a result of the serial reactor design, the energy efficiency of the system improved, and in particular, 7% of increase was found in at the same level of energy consumption. The mixed phase of VOCs (toluene and MEK) showed MEK as a limiting species in this study. As the inlet concentration rose from 20 to 100 ppmv, both energy yield and complete energy yield increased from 0.8 to 9.2 g/kWh and from 0.8 to 2.3 g/kWh, respectively.

Health effects of exposure to indoor volatile organic compounds from 1980 to 2017: A systematic review and meta-analysis

Exposure to volatile organic compounds (VOCs) indoors is thought to be associated with several adverse health effects. However, we still lack concentration-response (C-R) relationships between VOC levels in civil buildings and various health outcomes. For this paper, we conducted a systematic review and meta-analysis of observational studies to summarize related associations and C-R relationships. Four databases were searched to collect all relevant studies published between January 1980 and December 2017. A total of 39 studies were identified in the systematic review, and 32 of these were included in the meta-analysis. We found that the pooled relative risk (RR) for leukemia was 1.03 (95% CI: 1.01-1.05) per 1 μg/m³ increase of benzene and 1.25 (95%CI: 1.14-1.37) per 0.1 μg/m³ increase of butadiene. The pooled RRs for asthma were 1.08 (95% CI: 1.02-1.14), 1.02 (95% CI: 1.00-1.04), and 1.04 (95% CI: 1.02-1.06) per 1 μg/m³ increase of benzene, toluene, and p-dichlorobenzene, respectively. The pooled RR for low birth weight was 1.12 (95% CI: 1.05-1.19) per 1 μg/m³ increase of benzene. Our findings provide robust evidence for associations between benzene and leukemia, asthma, and low birth weight, as well as for health effects of some other VOCs.

Quantitative Health Risk Assessment of the Chronic Inhalation of Chemical Compounds in Healthcare and Elderly Care Facilities

Previous studies have described the chemical pollution in indoor air of healthcare and care facilities. From these studies, the main objective of this work was to conduct a quantitative health risk assessment of the chronic inhalation of chemical compounds by workers in healthcare and elderly care facilities (hospitals, dental and general practitioner offices, pharmacies and nursing homes). The molecules of interest were 36 volatile and 13 semi-volatile organic compounds. Several professional exposure scenarios were developed in these facilities. The likelihood and severity of side effects that could occur were assessed by calculating the hazard quotient for deterministic effects, and the excess lifetime cancer risk for stochastic effects. No hazard quotient was greater than 1. Three compounds had a hazard quotient above 0.1: 2-ethyl-1-hexanol in dental and general practitioner offices, ethylbenzene and acetone in dental offices. Only formaldehyde presented an excess lifetime cancer risk greater than 1 × 10⁻⁵ in dental and general practitioner offices (maximum value of 3.8 × 10⁻⁵ for general practitioners). The health risk for chronic inhalation of most compounds investigated did not appear to be of concern. Some values tend to approach the acceptability thresholds justifying a reflection on the implementation of corrective actions such as the installation of ventilation systems.

Construction of nanorod structure confined Pt@CeO2 catalyst by in-situ encapsulation strategy for low temperature catalytic oxidation of toluene

In this work, the Pt@CeO2 catalyst with the nanorod structure (Pt@CeO2-R) and the bunch structure (Pt@CeO2-B) were synthesized through in situ encapsulation strategy of Pt species in Ce-MOFs, respectively. It is discovered that the Pt@CeO2-R catalyst owned the best catalytic performance for toluene catalytic combustion, and this situation was mainly caused by the confinement of Pt nanoparticles in Ce-MOFs, which was related to the chemical state of Pt species, redox ability, and the amount of active oxygen species. Among them, the Pt@CeO2-R catalyst owns more Ce3+ species, rich Pt4+ species, and abundant active oxygen species due to the existence of confined structure, which were conducive to promote catalytic oxidation of toluene. In addition, the Pt@CeO2-R catalyst also exhibited more redox ability, which may speed up the catalytic reaction rates. On the contrary, the Pt/CeO2-R catalyst was synthesized through a simple impregnation method, and exhibited the poor activity for toluene catalytic combustion due to poor Pt4+ species and active oxygen species. Therefore, this work provides a feasible experimental basis for the study of different morphologies and encapsulated metal particles.

Formaldehyde, acrolein and other carbonyls in dwellings of university students. Levels and source characterization

Fifteen carbonyl compounds were investigated in the living rooms and bedrooms of 25 university student flats in the urban area of Ciudad Real (Central Southern Spain) in wintertime. Carbonyls were sampled using Radiello ® passive samplers refilled in the laboratory according to the method described in ISO 16000-3 Standard. The most abundant carbonyls in the living rooms and bedrooms were formaldehyde, acetone, acetaldehyde, hexaldehyde and butyraldehyde. The median concentration levels in the living rooms and bedrooms were: 28.6 and 34.2 μg m^-3 for formaldehyde, 18.3 and 23.1 μg m^-3 for acetone, 14.3 and 15.8 μg m^-3 for acetaldehyde, 11.4 and 14.1 μg m^-3 for hexaldehyde and 10.8 and 12.4 μg m^-3 for butyraldehyde. The median concentration of formaldehyde, benzaldehyde, valeraldehyde and hexaldehyde was significantly higher in the bedrooms than in the living rooms. Indoor concentrations were significantly higher than outdoor concentrations for all carbonyl measured, indicating that sources in the indoor environment are prevailing in all flats. Principal component analysis, multiple linear regressions and Spearman correlation coefficients were used to investigate the origin, the indoor pollutants determinants and to establish common sources between carbonyls. Eight components were extracted from the application of PCA to the indoor and outdoor measurements accounting for 97.7% of the total variance. Formaldehyde, acetone, acetaldehyde and acrolein presented different indoor sources. In the multiple linear regression analysis, higher formaldehyde concentrations were found in those living rooms with wood floor and smoking was positively associated to acetone, propionaldehyde, benzaldehyde and isovaleraldehyde. Formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde and benzaldehyde concentrations were compared with relevant international guidelines, being their concentrations below recommended values except acrolein, where all measured flats exceeded the reference levels; it would be important to focus on the characterization of emission sources of acrolein in indoor air in order to minimise the exposure and health risk.

Formaldehyde, aliphatic aldehydes (C2 -C11 ), furfural, and benzaldehyde in the residential indoor air of children and adolescents during the German Environmental Survey 2014-2017 (GerES V)

Indoor air concentrations of formaldehyde, furfural, benzaldehyde, and 11 aliphatic aldehydes (C₂ -C₁₁ ) were measured in residences of 639 participants in the German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Sampling was conducted using passive samplers over periods of approximately seven days for each participant. The most abundant compounds were formaldehyde and hexanal with median concentrations of 24.9 µg m^-3 and 10.9 µg m^-3 , respectively. Formaldehyde concentrations exceeded the Guide Value I recommended by the German Committee on Indoor Guide Values (Ausschuss für Innenraumrichtwerte - AIR) (0.10 mg m^-3 ) for 0.3% of the participating residences. The sum of aliphatic n-aldehydes between C₄ (butanal) and C₁₁ (undecanal) exceeded their Guide Value (0.10 mg m^-3 ) for 2.0% of the residences. The geometric mean concentrations of most aldehydes were lower than in the earlier GerES IV (2003-2006) study. Formaldehyde and hexanal concentrations, however, were comparable in both studies and showed no significant difference. Indoor aldehyde concentrations did not exhibit significant correlations with factors collected in questionnaires, such as the age of the participants, their socio-economic status, the location of the residence (former East/West Germany), migration background, tobacco exposure, and the type of furniture used. The validity of the passive sampler measurements was verified against active sampling techniques in a test chamber experiment.

Blood volatile organic aromatic compounds concentrations across adulthood in relation to total and cause specific mortality: A prospective cohort study

OBJECTIVE

We aimed to evaluate the relationship between blood volatile organic aromatic compounds (VOACs) across adulthood and mortality.

METHODS

A total of 16,968 participants from the National health and Nutrition Examination Surveys (NHANES 1988-1994 and 1999-2014) were included in the present study. Cox proportional hazards models were used to explore the associations between VOACs and total or cause-specific mortality.

RESULTS

A total of 1,282 deaths occurred among 16,968 participants with a median follow-up of 8.06 years. We observed significant positive dose-response relationship between VOACs including benzene, ethylbenzene, o-xylene, m-/p-xylene and BEX (the sum of benzene, ethylbenzene, m-/p-and o-xylene concentrations) and total mortality, the multiple adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were 1.24 (1.13, 1.36), 1.15 (1.04, 1.27), 1.10 (1.00, 1.23), 1.09 (1.01, 1.19) and 1.21 (1.08, 1.35), respectively. In addition, all VOACs significantly elevated risk of the mortality from cancer, and benzene was associated with risk of the mortality from heart disease and the HRs and 95% CIs was 1.39 (1.09-1.77). For non-smokers, benzene, ethylbenzene and BEX were associated with elevated risk of total mortality and the mortality from cancer, and benzene was associated with risk of the mortality from heart disease.

CONCLUSIONS

Blood VOACs are associated with increased risks of total and specific-cause mortality, which are also observed among non-smokers.

Indoor PM2.5, VOCs and asthma outcomes: A systematic review in adults and their home environments

INTRODUCTION

As the amount of time people spend indoors increases globally, exposure to indoor air pollutants has become an important public health concern. Asthma is a complex disease caused and/or exacerbated by increased exposure to diverse chemical, physical and biological exposures from multiple indoor and outdoor sources. This review aims to investigate the relationship between increased indoor PM and VOC concentrations (i.e. objectively measured) and the risk of adult asthma in higher-income countries.

METHODS

Eleven databases were systematically searched on the February 1, 2019 and again on the February 2, 2020. Articles were limited to those published since 1990. Reference lists were independently screened by three reviewers and authors were contacted to identify relevant articles. Backwards and forward citation chasing was used to identify further studies. Data were extracted from included studies meeting our eligibility criteria by three reviewers and assessed for quality using the Newcastle-Ottawa scale designed for case-control and cohort studies.

RESULTS

Twelve studies were included in a narrative synthesis. We found insufficient evidence to determine the effect of PM2.5 on asthma in the indoor home environment. However, there was strong evidence to suggest that VOCs, especially aromatic compounds, and aliphatic compounds, were associated with increased asthma symptoms.

DISCUSSION & CONCLUSION

Although no single exposure appears to be responsible for the development of asthma or its associated symptoms, the use of everyday products may be associated with increased asthma symptoms. To prevent poor health outcomes among the general population, health professionals and industry must make a concerted effort to better inform the general population of the importance of appropriate use of and storage of chemicals within the home as well as better health messaging on product labelling.

Estimating household exposure to moth repellents p-dichlorobenzene and naphthalene and the relative contribution of inhalation pathway in a sample of Japanese children

p-Dichlorobenzene (DCB) and naphthalene (NP) used as moth repellents in indoor environments are suspected to be carcinogenic. To evaluate their adverse effects on health with chronic exposure in the general population, especially children, we need to know their amounts absorbed by the body and the relationships between their amounts and air quality in residences. At present, little is known worldwide about them. This study examined the daily intakes of DCB and NP by Japanese children via all exposure pathways and the contribution of indoor air quality to the intakes. First-morning void urine samples from the subjects aged 6 to 15 years and air samples in their bedrooms were collected. Airborne NP and DCB and their urinary metabolites were measured. Significant correlations were detected between their airborne concentrations and the urinary excretion amounts of their corresponding metabolites. The absorption amounts of DCB and NP by inhalation of the children while at home were calculated to be 26 and 2.0 ng/kg b.w./h, respectively, as median values. The daily intake was estimated to be 2.4 and 0.90 μg/kg b.w./d (median), respectively. The fractions (median) of inhalation absorption amounts to overall absorption amounts for DCB and NP were 30% and 5%, respectively. In children living in residences where the indoor air concentrations of these compounds were more than half the level of each guideline value for indoor air quality, the main exposure route for their absorption was considered to be inhalation while at home. The indoor concentrations of DCB exceeded the lifetime excess cancer risk level of 10^-4 in 22% of the residences and 10^-3 in 9% of them. Our findings indicate the need to further reduce airborne concentrations of DCB in Japanese residences to prevent its adverse effects on the health of Japanese children.

Relationship between air pollution levels in Madrid and the natural history of idiopathic pulmonary fibrosis: severity and mortality

Objective

We aimed to assess the relationship between major air pollutants and the natural history and mortality of idiopathic pulmonary fibrosis (IPF).

Methods

We conducted a retrospective cohort study from 2013 to 2019 among 52 patients with IPF from the pneumology department of a tertiary hospital. According to their geocoded residential address, each patient was assigned a mean concentration of carbon monoxide (CO), nitrogen dioxide, particulate matter 2.5 and 10, ozone, and sulfur dioxide, as measured at a single surveillance station in central Madrid, Spain. We analyzed forced vital capacity (FVC), CO diffusing capacity, 6-minute walking test, degree of dyspnea, radiologic pattern, and signs of pulmonary hypertension in all patients.

Results

Patients’ mean age was 66 ± 10 years, and 79% were men. The mean predicted FVC was 78.9 ± 0.5%. Forty-two patients met the criteria for severe disease, and 18 patients died. Mortality was significantly associated with increased CO exposure (for each 0.1 mg/m² increase: odds ratio 2.45, 95% confidence interval 1.39–4.56). We observed no association between any of the other investigated contaminants and IPF mortality or severity.

Conclusions

Air pollution, specifically that caused by carbon monoxide, can increase mortality in patients with IPF.

Air pollution and lung function in children

In this narrative review, we summarize the literature and provide updates on recent studies of air pollution exposures and child lung function and lung function growth. We include exposures to outdoor air pollutants that are monitored and regulated through air quality standards, and air pollutants that are not routinely monitored or directly regulated, including wildfires, indoor biomass and coal burning, gas and wood stove use, and volatile organic compounds. Included is a more systematic review of the recent literature on long-term air pollution and child lung function because this is an indicator of future adult respiratory health and exposure assessment tools have improved dramatically in recent years. We present "summary observations" and "knowledge gaps." We end by discussing what is known about what can be done at the individual/household, local/regional, and national levels to overcome structural impediments, reduce air pollution exposures, and improve child lung function. We found a large literature on adverse air pollution effects on children's lung function level and growth; however, many questions remain. Important areas needing further research include whether early-life effects are fixed or reversible; and what are windows of increased susceptibility, long-term effects of repeated wildfire events, and effects of air quality interventions.

Considering environmental exposures to per- and polyfluoroalkyl substances (PFAS) as risk factors for hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy (HDP), including preeclampsia and gestational hypertension, lead to significant maternal morbidity and in some cases, maternal mortality. Environmental toxicants, especially those that disrupt normal placental and endothelial function, are emerging as potential risk factors for HDP. Per- and polyfluoroalkyl substances (PFAS) are a large group of ubiquitous chemicals found in consumer products, the environment, and increasingly in drinking water. PFAS have been associated with a multitude of adverse health effects, including dyslipidemia, hypertension, and more recently, HDP. In this review, we present epidemiological and mechanistic evidence for the link between PFAS and HDP and recommend next steps for research and prevention efforts. To date, epidemiological studies have assessed associations between only ten of the thousands of PFAS and HDP. Positive associations between six PFAS (PFOA, perfluorooctanoic acid; PFOS, perfluorooctane sulfonic acid; PFHxS, perfluorohexane sulfonic acid; PFHpA, perfluoroheptanoic acid; PFBS, perfluorobutanesulfonic acid; and PFNA, perfluoronanoic acid) and risk for HDP have been reported in some, but not all, studies. PFAS disrupt placental and immune function, cause oxidative stress, and disrupt lipid metabolism. These physiological disruptions may be mechanisms through which PFAS can lead to HDP. Overall, limited epidemiological evidence and plausible mechanisms support PFAS as risk factors for HDP. More research is needed in diverse, well-powered cohorts that assess exposures to as many PFAS as possible. Such research should consider not only individual PFAS but also the totality of exposures to PFAS and other environmental chemicals. Pregnant women may be a group that is vulnerable to PFAS exposure, and as such HDP risk should be considered by policymakers setting PFAS exposure limits. In the interim, medical and public health professionals in regions with PFAS contamination could provide short-term solutions in the form of patient-level prevention, increased monitoring, and early intervention for HDP.

Work Exposure to VOC in Storage Areas of Retail Stores

Poor indoor air quality (IAQ) has been linked to airway disease and early deaths. The ESQUISSE study of IAQ conducted by the French Research and Safety Institute (INRS), characterized the concentrations of various volatile organic compounds (VOCs) in 10 retail stores and storage areas. The IAQ was generally better in sales areas than storage areas, which are more often unventilated and overloaded with new products. For example, in clothing stores, formaldehyde concentrations between 29.0 and 45.0 µg m-3 were measured in non-ventilated storage areas located in the basement; in sales areas, concentrations did not exceed 10.2 µg m-3. Similarly, total VOC (TVOC) concentrations in the two main storage areas were 1153 and 1223 µg m-3 toluene equivalent, whereas they were less than 77.0 µg m-3 toluene equivalent in all sales areas. Many employees work in these high-exposure areas either temporarily or for the entire day, unpacking boxes, placing products on shelves, or collecting products. Reporting primarily on formaldehyde, toluene, or TVOC concentrations, this article shows, in addition to the distinction between sales and storage areas, how an unpacking task can affect an employee's exposure, and an example of the impact of ambient temperature on VOC concentrations. The results presented clearly highlight the issue of occupational exposure of workers in storage areas.

Air pollution exposure-the (in)visible risk factor for respiratory diseases

There is increasing interest in understanding the role of air pollution as one of the greatest threats to human health worldwide. Nine of 10 individuals breathe air with polluted compounds that have a great impact on lung tissue. The nature of the relationship is complex, and new or updated data are constantly being reported in the literature. The goal of our review was to summarize the most important air pollutants and their impact on the main respiratory diseases (chronic obstructive pulmonary disease, asthma, lung cancer, idiopathic pulmonary fibrosis, respiratory infections, bronchiectasis, tuberculosis) to reduce both short- and the long-term exposure consequences. We considered the most important air pollutants, including sulfur dioxide, nitrogen dioxide, carbon monoxide, volatile organic compounds, ozone, particulate matter and biomass smoke, and observed their impact on pulmonary pathologies. We focused on respiratory pathologies, because air pollution potentiates the increase in respiratory diseases, and the evidence that air pollutants have a detrimental effect is growing. It is imperative to constantly improve policy initiatives on air quality in both high- and low-income countries.

Exposure to formaldehyde and asthma outcomes: A systematic review, meta-analysis, and economic assessment

BACKGROUND

Every major federal regulation in the United States requires an economic analysis estimating its benefits and costs. Benefit-cost analyses related to regulations on formaldehyde exposure have not included asthma in part due to lack of clarity in the strength of the evidence.

OBJECTIVES

1) To conduct a systematic review of evidence regarding human exposure to formaldehyde and diagnosis, signs, symptoms, exacerbations, or other measures of asthma in humans; and 2) quantify the annual economic benefit for decreases in formaldehyde exposure.

METHODS

We developed and registered a protocol in PROSPERO (Record ID #38766, CRD 42016038766). We conducted a comprehensive search of articles published up to April 1, 2020. We evaluated potential risk of bias for included studies, identified a subset of studies to combine in a meta-analysis, and rated the overall quality and strength of the evidence. We quantified economics benefit to children from a decrease in formaldehyde exposure using assumptions consistent with EPA's proposed formaldehyde rule.

RESULTS

We screened 4,821 total references and identified 150 human studies that met inclusion criteria; of these, we focused on 90 studies reporting asthma status of all participants with quantified measures of formaldehyde directly relevant to our study question. Ten studies were combinable in a meta-analysis for childhood asthma diagnosis and five combinable for exacerbation of childhood asthma (wheezing and shortness of breath). Studies had low to probably-low risk of bias across most domains. A 10-μg/m3 increase in formaldehyde exposure was associated with increased childhood asthma diagnosis (OR = 1.20, 95% CI: [1.02, 1.41]). We also found a positive association with exacerbation of childhood asthma (OR = 1.08, 95% CI: [0.92, 1.28]). The overall quality and strength of the evidence was rated as "moderate" quality and "sufficient" for asthma diagnosis and asthma symptom exacerbation in both children and adults. We estimated that EPA's proposed rule on pressed wood products would result in 2,805 fewer asthma cases and total economic benefit of $210 million annually.

CONCLUSION

We concluded there was "sufficient evidence of toxicity" for associations between exposure to formaldehyde and asthma diagnosis and asthma symptoms in both children and adults. Our research documented that when exposures are ubiquitous, excluding health outcomes from benefit-cost analysis can underestimate the true benefits to health from environmental regulations.

Pulmonary Health Effects of Indoor Volatile Organic Compounds-A Meta-Analysis

Volatile organic compounds (VOCs) are commonly found in consumer products, including furniture, sealants and paints. Thus, indoor VOCs have become a public health concern, especially in high-income countries (HICs), where people spend most of their time indoors, and indoor and outdoor air exchange is minimal due to a lack of ventilation. VOCs produce high levels of reaction with the airway epithelium and mucosa membrane and is linked with pulmonary diseases. This paper takes a stock of the literature to assess the strength of association (measured by effect size) between VOCs and pulmonary diseases with the focus on asthma and its related symptoms by conducting a meta-analysis. The literature was searched using the PubMed database. A total of 49 studies that measured VOCs or VOC types and pulmonary health outcomes were included in the analysis. The results of these studies were tabulated, and standard effect size of each study was computed. Most studies were conducted in high-income countries, including France (n = 7), Japan (n = 7) and the United States (n = 6). Our analysis suggests that VOCs have a medium-sized effect on pulmonary diseases, including the onset of asthma (effect size (or Cohen's d) ~0.37; 95% confidence interval (CI) = 0.25-0.49; n = 23) and wheezing (effective size ~0.26; 95% CI = 0.10-0.42; n = 10). The effect size also varied by country, age and disease type. Multiple stakeholders must be engaged in strategies to mitigate and manage VOC exposure and its associated pulmonary disease burden.

Links between air pollution and COVID-19 in England

In December 2019, a novel disease, coronavirus disease 19 (COVID-19), emerged in Wuhan, People's Republic of China. COVID-19 is caused by a novel coronavirus (SARS-CoV-2) presumed to have jumped species from another mammal to humans. This virus has caused a rapidly spreading global pandemic. To date, over 300,000 cases of COVID-19 have been reported in England and over 40,000 patients have died. While progress has been achieved in managing this disease, the factors in addition to age that affect the severity and mortality of COVID-19 have not been clearly identified. Recent studies of COVID-19 in several countries identified links between air pollution and death rates. Here, we explored potential links between major fossil fuel-related air pollutants and SARS-CoV-2 mortality in England. We compared current SARS-CoV-2 cases and deaths from public databases to both regional and subregional air pollution data monitored at multiple sites across England. After controlling for population density, age and median income, we show positive relationships between air pollutant concentrations, particularly nitrogen oxides, and COVID-19 mortality and infectivity. Using detailed UK Biobank data, we further show that PM_2.5 was a major contributor to COVID-19 cases in England, as an increase of 1 m³ in the long-term average of PM_2.5 was associated with a 12% increase in COVID-19 cases. The relationship between air pollution and COVID-19 withstands variations in the temporal scale of assessments (single-year vs 5-year average) and remains significant after adjusting for socioeconomic, demographic and health-related variables. We conclude that a small increase in air pollution leads to a large increase in the COVID-19 infectivity and mortality rate in England. This study provides a framework to guide both health and emissions policies in countries affected by this pandemic.

Association between sum of volatile organic compounds and occurrence of building-related symptoms in humans: A study in real full-scale laboratory houses

It is well known that the indoor environment, particularly indoor air quality (IAQ), has significant effects on building-related symptoms (BRSs) in humans, such as irritation of mucosal membranes, headaches, and allergies, such as asthma and atopic dermatitis. In 2017, Chiba University launched the "Chemiless Town Project Phase 3" to investigate the relationship between IAQ and human health. Two laboratory houses (LHs) were built on a university campus in which the interiors and exteriors were similar, but the levels of indoor air volatile organic compounds (VOCs) were different. A total of 141 participants evaluated IAQ using their sensory perception. There was a significant relationship between differences in VOC levels and BRSs occurrence (OR: 6.89, 95% CI: 1.40-33.98). It was suggested that people with a medical history of allergies (OR: 5.73, 95% CI: 1.12-29.32) and those with a high sensitivity to chemicals (OR: 8.82, 95% CI: 1.16-67.16) tended to experience BRSs. Thus, when buildings are constructed, people with a history of allergies or with a sensitivity to chemicals may be at high risk to BRSs, and it is important to pay attention to IAQ to prevent BRSs.

Indoor volatile organic compounds exposures and risk of childhood acute leukemia: a case-control study in shanghai

A case-control study was conducted to investigate the relationship between indoor air pollution and childhood acute leukemia (AL) in Shanghai. 97 cases and 148 gender-, age-, and residence-matched controls were included. Indoor air pollution was evaluated by questionnaires and quantitative measurement including 14 volatile organic compounds (VOCs) and nitrogen dioxide (NO₂) in the homes of the two groups. The levels of individual VOCs, VOC families, TVOC (sum of the concentrations of the individual VOCs) and NO₂ were compared between the two groups. Exposure to styrene and butyl alcohol were associated with an increased risk of childhood AL (styrene: odds ratio (OR)=2.33, 95% confidence interval (CI): 1.07-5.07; butyl alcohol: OR = 2.51, 95%CI: 1.19-5.28); 4th quartile of chlorinated hydrocarbons (OR = 2.52, 95%CI: 1.02-6.26) and 3rd quartile of TVOC (OR = 4.03, 95%CI: 1.06-6.81) had significant higher ORs for childhood AL compared with that in the lowest quartiles. Elevated levels of individual VOCs, VOC families and TVOC were also associated with self-reported risk factors. Our findings suggest that VOCs exposure was associated with an elevated risk of childhood AL, underscore that more attention should be paid to indoor air pollution as a risk factor of childhood AL.

Toxicological responses of BEAS-2B cells to repeated exposures to benzene, toluene, m-xylene, and mesitylene using air-liquid interface method

In order to reduce exposure to toxic chemicals, the European REACH regulation (1907/2006) recommends substituting toxic molecules with compounds that are less harmful to human health and the environment. Toluene is one of the most frequently used solvents in industries despite its toxicity. The objective of this study is to better understand and compare the toxicity of toluene and its homologues in a bronchial cell model. Thus, human bronchial BEAS-2B cells were exposed to steams of toluene, m-xylene, mesitylene (1,3,5-trimethylbenzene), and benzene (20 and 100 ppm). Exposure was carried out using an air-liquid interface (ALI) system (Vitrocell) during 1 h/day for 1, 3, or 5 days. Cytotoxicity, xenobiotic metabolism enzyme gene expression, and inflammatory response were evaluated following cell exposures. BEAS-2B cell exposure to toluene and its homologues revealed the involvement of major (CYP2E1) and minor metabolic pathways (CYP1A1). A late induction of genes (EPHX1, DHDH, ALDH2, and ALDH3B1) was measured from Day 3 and can be linked to the formation of metabolites. An increase in the secretion level of inflammatory markers (TNF-α, IL-6, IL-8, MCP-1, and GM-CSF) was also observed. In parallel, regulation between inflammatory mediators and the expression of transmembrane glycoprotein mucin MUC1 was also studied. This in vitro approach with ALI system points out the relevance of conducting repeated exposures to detect potential late effects. The difference recorded after cell exposure to toluene and its homologues highlights the importance of substitution principle.

The joint effect of ambient air pollution and agricultural pesticide exposures on lung function among children with asthma

BACKGROUND

Ambient environmental pollutants have been shown to adversely affect respiratory health in susceptible populations. However, the role of simultaneous exposure to multiple diverse environmental pollutants is poorly understood.

OBJECTIVE

We applied a multidomain, multipollutant approach to assess the association between pediatric lung function measures and selected ambient air pollutants and pesticides.

METHODS

Using data from the US EPA and California Pesticide Use Registry, we reconstructed three months prior exposure to ambient air pollutants ((ozone (O₃), nitrogen dioxide (NO₂), particulate matter with a median aerodynamic diameter < 2.5 μm (PM_2.5) and <10 μm (PM₁₀)) and pesticides (organophosphates (OP), carbamates (C) and methyl bromide (MeBr)) for 153 children with mild intermittent or mild persistent asthma from the San Joaquin Valley of California, USA. We implemented Bayesian kernel machine regression (BKMR) to estimate the association between simultaneous exposures to air pollutants and pesticides and lung function measures (forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75)).

RESULTS

In BKMR analysis, the overall effect of mixtures (pollutants and pesticides) was associated with reduced FEV₁ and FVC, particularly when all the environmental exposures were above their 60th percentile. For example, the effect of the overall mixture at the 70th percentile (compared to the median) was a -0.12SD (-50 mL, 95% CI: -180 mL, 90 mL) change in the FEV₁ and a -0.18SD (-90 mL, 95% CI: -240 mL, 60 mL) change in the FVC. However, 95% credible intervals around all of the joint effect estimates contained the null value.

CONCLUSION

At this agricultural-urban interface, we observed results from multipollutant analyses, suggestive of adverse effects on some pediatric lung function measures following a cumulative increase in ambient air pollutants and agricultural pesticides. Given the uncertainty in effect estimates, this approach should be explored in larger studies.

Indoor air pollution, physical and comfort parameters related to schoolchildren's health: Data from the European SINPHONIE study

Substantial knowledge is available on the association of the indoor school environment and its effect among schoolchildren. In the same context, the SINPHONIE (School indoor pollution and health: Observatory network in Europe) conducted a study to collect data and determine the distribution of several indoor air pollutants (IAPs), physical and thermal parameters and their association with eye, skin, upper-, lower respiratory and systemic disorder symptoms during the previous three months. Finally, data from 115 schools in 54 European cities from 23 countries were collected and included 5175 schoolchildren using a harmonized and standardized protocol. The association between exposures and the health outcomes were examined using logistic regression models on the environmental stressors assessed in classroom while adjusting for several confounding factors; a VOC (volatile organic compound) score defined as the sum of the number of pollutants to which the children were highly exposed (concentration > median of the distribution) in classroom was also introduced to evaluate the multiexposure - outcome association. Schoolchildren while adjusting for several confounding factors. Schoolchildren exposed to above or equal median concentration of PM_2.5, benzene, limonene_, ozone and radon were at significantly higher odds of suffering from upper, lower airways, eye and systemic disorders. Increased odds were also observed for any symptom (sick school syndrome) among schoolchildren exposed to concentrations of limonene and ozone above median values. Furthermore, the risks for upper and lower airways and systemic disorders significantly increased with the VOCs score. Results also showed that increased ventilation rate was significantly associated with decreased odds of suffering from eye and skin disorders whereas similar association was observed between temperature and upper airways symptoms. The present study provides evidence that exposure to IAPs in schools is associated with various health problems in children. Further investigations are needed to confirm our findings.

Volatile Organic Compounds (VOCs) from Wood and Wood-Based Panels: Methods for Evaluation, Potential Health Risks, and Mitigation

Volatile organic compounds (VOCs) are contained in various construction materials and interior equipment. Their higher concentrations in the indoor air are associated with negative effects on human health and are disputed in terms of health risk, since people spend a considerable part of their lifetime indoors. Therefore, the presence of VOCs in indoor air is a case of concern regarding sick building syndrome (SBS). From a historical point of view, wood and wood-based panels represent a widely used material. Nevertheless, wood appears to be nowadays a product and a material of a sustainable future. Depending on wood extractives’ composition and an abundance of diverse wood species, different profiles of volatiles are emitted. In case of wood-based panels, the impact of adhesives and additives that are essentially applied aiming to adjust the panels’ properties is even enriching this cocktail of chemicals. This paper comprises the issue of VOCs emitted from wood and wood-based panels. The most abundant VOCs were summarized. The options of VOCs for analytical determination from these matrixes are described with their benefits and limitations.