Variations of formaldehyde and VOC levels during 3 years in new and older homes

Association Between Home Renovation and Sleeping Problems Among Children Aged 6-18 Years: A Nationwide Survey in China

BACKGROUND

Although the indoor environment has been proposed to be associated with childhood sleep health, to our knowledge no study has investigated the association between home renovation and childhood sleep problems.

METHODS

The study included 186,470 children aged 6-18 years from the National Chinese Children Health Study (2012-2018). We measured childhood sleeping problems via the Chinese version of the Sleep Disturbance Scale for Children (C-SDSC). Information on home renovation exposure within the recent 2 years was collected via parent report. We estimated associations between home renovation and various sleeping problems, defined using both continuous and categorized (binary) C-SDSC t-scores, using generalized mixed models. We fitted models with city as a random effect variable, and other covariates as fixed effects.

RESULTS

Out of the overall participants, 89,732 (48%) were exposed to recent home renovations. Compared to the unexposed group, children exposed to home renovations had higher odds of total sleep disorder (odd ratios [OR] = 1.3; 95% confidence interval [CI] = 1.2, 1.4). Associations varied when we considered different types of home renovation materials. Children exposed to multiple types of home renovation had higher odds of sleeping problems. We observed similar findings when considering continuous C-SDSC t-scores. Additionally, sex and age of children modified the associations of home renovation exposure with some of the sleeping problem subtypes.

CONCLUSIONS

We found that home renovation was associated with higher odds of having sleeping problems and that they varied when considering the type of renovation, cumulative exposure, sex, and age differences.

Self-Luminous Wood Coatings with Carbon Dots/TiO2 Grafted Afterglow SrAl2O4: Eu, Dy Core-Shell Phosphors for Long-Lasting Formaldehyde Removal

Long-term relief of indoor volatile pollution has become a competitive issue worldwide in both visible and dark environments. A novel self-luminous wood coating with carbon dots (CDs)/titanium dioxide (TiO₂) nanomaterial coated SrAl₂O₄: Eu²⁺, Dy³⁺ (CDs/TiO₂@SAO) composite was prepared for the long-term degradation of formaldehyde through a simple sol-gel method. The microstructure, chemical composition, ultraviolet-visible (UV-vis) spectra, and long-lasting fluorescence of the CDs/TiO₂@SAO photocatalyst were analyzed to illustrate the mechanism for degrading formaldehyde. The obtained CDs with a particle size of ~2-7 nm have a good graphite structure and presented good absorption in visible light. In addition, owing to the synergistic effect of the CDs/TiO₂ nanomaterial coating layer and the long-afterglow luminescence of the SAO phosphor, the CDs/TiO₂@SAO composite can absorb a part of the visible light for photocatalytic degradation and store luminous energy efficiently at daytime so as to give out visible luminescence continuously for a few hours in the darkness. Furthermore, the functional wood coatings with CDs/TiO₂@SAO composite presented continuous and efficient photocatalytic activity in the presence and absence of light exposure. The current research could provide a new strategy for designing an efficient photocatalyst for degrading formaldehyde pollution in the daytime with a visible light supply and in an indoor dark environment without an external light source.

A review of indoor Gaseous organic compounds and human chemical Exposure: Insights from Real-time measurements

Gaseous organic compounds, mainly volatile organic compounds (VOCs), have become a wide concern in various indoor environments where we spend the majority of our daily time. The sources, compositions, variations, and sinks of indoor VOCs are extremely complex, and their potential impacts on human health are less understood. Owing to the deployment of the state-of-the-art real-time mass spectrometry during the last two decades, our understanding of the sources, dynamic changes and chemical transformations of VOCs indoors has been significantly improved. This review aims to summarize the key findings from mass spectrometry measurements in recent indoor studies including residence, classroom, office, sports center, etc. The sources and sinks, compositions and distributions of indoor VOCs, and the factors (e.g., human activities, air exchange rate, temperature and humidity) driving the changes in indoor VOCs are discussed. The physical and chemical processes of gas-particle partitioning and secondary oxidation processes of VOCs, and their impacts on human health are summarized. Finally, the recommendations for future research directions on indoor VOCs measurements and indoor chemistry are proposed.

Psychological Antecedents of the Intention to Open the Windows at Home and Exposure to a Ventilation Recommendation

Objective

The psychological antecedents of the intention to open the windows at home were explored through the Theory of Planned Behavior (TPB), supplemented with Habits regarding the behavior and contextual factors.

Design

A four-treatment design compared the effect of an exposure to a recommendation about home ventilation and the effect of one's own awareness odors (negative vs. positive) as a manipulated variable. Two quasi-experimental online surveys were conducted. A student sample (Study 1; N = 159) was replicated with a general population sample (Study 2; N = 338).

Results

Multiple hierarchical regression models were conducted (3 for Study 1; 3 for Study 2). The extended TPB model provided stable predictors explaining around sixty percent of variance. Attitude and Habits were the main predictors of window openings, Perceived Behavioral control as a secondary predictor. Perceived Behavioral Control contributed significatively with a negative interaction with Attitudes. Odor awareness decreased Intention to manually ventilate. No effect of recommendation was observed.

Discussion

The results filled a gap in the literature about the willingness to manually ventilate at home and efficacy of a recommendation. Practical implications argue that beyond a generic recommendation, effective messages need to be tailored regarding the determinants of willingness to open the windows.

Probabilistic Prediction Models and Influence Factors of Indoor Formaldehyde and VOC Levels in Newly Renovated Houses

Rapid urbanization has promoted house renovations and refurbishment in urban and rural cities. Indoor pollutants emitted through renovations and refurbishment processes have raised public concerns owing to their adverse effects on human health. In the present study, the sources of formaldehyde and specific volatile organic compounds (VOCs) are used to model the health effects associated with exposure to formaldehyde and specific VOCs and the loading factors of building materials for newly renovated homes. The present study is carried out to identify the sources of formaldehyde and specific VOCs in newly renovated houses and develop probabilistic prediction models of the health effects to explore the health risks of residents and the potential contributions of multilayer wood materials responsible for indoor pollutants. In living rooms and bedrooms, the average concentrations of formaldehyde and TVOCs in closed window conditions were higher than those in opened window conditions. Multi-layer wooden structures were a significant predictor of indoor VOC concentrations in houses. The 95 percentile values of Monte Carlo simulations (MCS P95) of the hazard index and cancer risk were lower and slightly higher than the acceptable level, respectively. Prediction models for the concentrations of formaldehyde and selected VOCs in newly renovated houses were first established using probabilistic and sensitive approaches. The multi-layer wood materials, including the wooden floor, cold paint multi-layer wooden materials, and multi-layer materials for system furniture, were responsible for the contribution of these levels of formaldehyde and selected VOCs in the newly renovated houses. Our results provide a strategy for eliminating indoor pollutants emitted from construction and building/furnishing materials.

Association between maternal exposure to indoor air pollution and offspring congenital heart disease: a case–control study in East China

Background

Previous research suggested an association between maternal exposure to ambient air pollutants and the risk of congenital heart disease (CHD). However, the effect of individual prenatal exposure to indoor air pollutants on CHD occurrence was not reported.

Methods

We performed a hospital-based case–control study to investigate the association between personal air pollution exposure during pregnancy and the risk of CHD in offspring. A total of 44 cases and 75 controls were included from two hospitals in East China. We investigated maternal and residential environmental characteristics using a questionnaire and obtained personal indoor air samples to assess particulate matter (PM) and volatile organic compounds (VOCs) from 22–30 gestational weeks. Formaldehyde, benzene, toluene, xylene, total volatile organic compounds (TVOCs), PM_2.5, and PM₁₀ were assessed. Logistic regression was performed to assess associations and interactions between individual indoor air pollutants and CHD after adjusting for confounders. The potential residential environmental factors affecting the risks of indoor air pollutants on CHD were also assessed.

Results

Median TVOC (0.400 vs. 0.005 mg/m³, P < 0.001) exposure levels in cases were significantly higher than controls. A logistic regression model adjusted for confounders revealed that exposure to high levels of indoor TVOCs (AOR 7.09, 95% CI 2.10–23.88) during pregnancy was associated with risks for CHD and the occurrence of some major CHD subtype in offspring. These risk effects were enhanced in pregnant women living in a newly renovated house but were mitigated by household use of smoke ventilators when cooking. We observed a positive interaction of maternal exposure to TVOCs and PM_2.5 and the risk for CHD.

Conclusions

Maternal exposure to indoor VOCs and PMs may increase the risk of giving birth to foetuses with CHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13174-0.

Influencing factors of carbonyl compounds and other VOCs in commercial airliner cabins: On-board investigation of 56 flights

Volatile organic compounds (VOCs) as a non-negligible aircraft cabin air quality (CAQ) factor influence the health and comfort of passengers and crew members. On-board measurements of carbonyls (short-chain (C₁ -C₆ )) and other volatile organic compounds (VOCs, long-chain (C₆ -C₁₆ )) with a total of 350 samples were conducted in 56 commercial airliner cabins covering 8 aircraft models in this study. The mean concentration for each individual carbonyl compound was between 0.3 and 8.3 μg/m³ (except for acrolein & acetone, average = 20.7 μg/m³ ) similar to the mean concentrations of other highly detected VOCs (long-chain (C₆ -C₁₆ ), 97% of which ranged in 0-10 μg/m³ ) in aircraft cabins. Formaldehyde concentrations in flights were significantly lower than in residential buildings, where construction materials are known formaldehyde sources. Acetone is a VOC emitted by humans, and its concentration in flights was similar to that in other high-occupant density transportation vehicles. The variation of VOC concentrations in different flight phases of long-haul flights was the same as that of CO₂ concentration except for the meal phase, which indicates the importance of cabin ventilation in diluting the gaseous contaminants, while the sustained and slow growth of the VOC concentrations during the cruising phase in short-haul flights indicated that the ventilation could not adequately dilute the emission of VOCs. For the different categories of VOCs, the mean concentration during the cruising phase of benzene series, aldehydes, alkanes, other VOCs (detection rate > 50%), and carbonyls in long-haul flights was 44.2 µg/m³ , 17.9 µg/m³ , 18.6 µg/m³ , 31.5 µg/m³ , and 20.4 µg/m³  lower than those in short-haul flights, respectively. Carbonyls and d-limonene showed a significant correlation with meal service (p < 0.05). Unlike the newly decorated rooms or new vehicles, the inner materials were not the major emission sources in aircraft cabins. Practical Implications. The on-board measurements of 56 flights enrich the VOC database of cabin environment, especially for carbonyls. The literature review of carbonyls in the past 20 years contributes to the understanding the current status of cabin air quality (CAQ). The analysis of VOC concentration variation for different flight phases, flight duration, and aircraft age lays a foundation for exploring effective control methods, including ventilation and purification for cabin VOC pollution. The enriched VOC data is helpful to explore the key VOCs of aircraft cabin environment and to evaluate the acute/chronic health exposure risk of pollutants for passengers and crew members.

Spatial distribution of health risks for residents located close to solvent-consuming industrial VOC emission sources

Emissions derived from the consumption of organic solvents have been proven to be the primary industrial source of volatile organic compounds (VOCs). In conjunction with epidemiologic studies, water-based paints (WBPs) and solvent-based paints (SBPs) were selected as representatives of newly developed solvents and traditional solvents, respectively, to simulate the effects of consuming solvents emitted during industrial production. And non-carcinogenic and carcinogenic risks to residents near emission sources were studied in detail. The results showed that the spatial distribution of health risks varied with meteorological conditions and type of emission source, and the prevailing wind direction strongly affected the distribution range and shape of the influenced area. The areas of influence maximized on heavy-polluting days for both WBP and SBP emission sources with the total span reaching 804 m and 16 km, respectively; meanwhile, the areas of influence for carcinogenic risk resulting from WBP emission sources were 1.2 and 2.3 times greater than those measured on fine and rainy days, respectively, and 1.8 and 2.9 times greater for SBP emission sources. Compared with WBPs, the total spans of negatively influenced regions resulting from SBP emission sources were 10.4, 12.5 and 19.9 times greater on fine, rainy and heavy-polluting days, respectively. Therefore, carcinogenic risk was the dominant health threat for populations residing close to solvent-consuming industrial emission sources. The findings suggest that newly developed solvents are capable of significantly reducing consequent health threats, nevertheless, they could still pose occasional threats to nearby residents under specific meteorological conditions.

Volatile Organic Compounds in Underground Shopping Districts in Korea

Underground shopping districts (USDs) are susceptible to severe indoor air pollution, which can adversely impact human health. We measured 24 volatile organic compounds (VOCs) in 13 USDs throughout South Korea from July to October 2017, and the human risk of inhaling hazardous substances was evaluated. The sum of the concentrations of the 24 VOCs was much higher inside the USDs than in the open air. Based on factor analysis, six indoor air pollution sources were identified. Despite the expectation of a partial outdoor effect, the impacts of the indoor emissions were significant, resulting in an indoor/outdoor (I/O) ratio of 5.9 and indicating elevated indoor air pollution. However, the effects of indoor emissions decreased, and the contributions of the pollution sources reduced when the USD entrances were open and the stores were closed. Although benzene, formaldehyde, and acetaldehyde exhibited lower concentrations compared to previous studies, they still posed health risks in both indoor and outdoor settings. Particularly, while the indoor excess cancer risk (ECR) of formaldehyde was ~10 times higher than its outdoor ECR, benzene had a low I/O ratio (1.1) and a similar ECR value. Therefore, indoor VOC concentrations could be reduced by managing inputs of open air into USDs.

High-Resolution Exposure Assessment for Volatile Organic Compounds in Two California Residences

Time spent in residences substantially contributes to human exposure to volatile organic compounds (VOCs). Such exposures have been difficult to study deeply, in part because VOC concentrations and indoor occupancy vary rapidly. Using a fast-response online mass spectrometer, we report time-resolved exposures from multi-season sampling of more than 200 VOCs in two California residences. Chemical-specific source apportionment revealed that time-averaged exposures for most VOCs were mainly attributable to continuous indoor emissions from buildings and their static contents. Also contributing to exposures were occupant-related activities, such as cooking, and outdoor-to-indoor transport. Health risk assessments are possible for a subset of observed VOCs. Acrolein, acetaldehyde, and acrylic acid concentrations were above chronic advisory health guidelines, whereas exposures for other assessable species were typically well below the guideline levels. Studied residences were built in the mid-20th century, indicating that VOC emissions even from older buildings and their contents can substantially contribute to occupant exposures.

Indoor air quality in new and renovated low-income apartments with mechanical ventilation and natural gas cooking in California

This paper presents pollutant concentrations and performance data for code-required mechanical ventilation equipment in 23 low-income apartments at 4 properties constructed or renovated 2013-2017. All apartments had natural gas cooking burners. Occupants pledged to not use windows for ventilation during the study but several did. Measured airflows of range hoods and bathroom exhaust fans were lower than product specifications. Only eight apartments operationally met all ventilation code requirements. Pollutants measured over one week in each apartment included time-resolved fine particulate matter (PM_2.5 ), nitrogen dioxide (NO₂ ), formaldehyde and carbon dioxide (CO₂ ) and time-integrated formaldehyde, NO₂ and nitrogen oxides (NO_X ). Compared to a recent study of California houses with code-compliant ventilation, apartments were smaller, had fewer occupants, higher densities, and higher mechanical ventilation rates. Mean PM_2.5 , formaldehyde, NO₂ , and CO₂ were 7.7 µg/m³ , 14.1, 18.8, and 741 ppm in apartments; these are 4% lower, 25% lower, 165% higher, and 18% higher compared to houses with similar cooking frequency. Four apartments had weekly PM_2.5 above the California annual outdoor standard of 12 µg/m³ and also discrete days above the World Health Organization 24-hour guideline of 25 µg/m³ . Two apartments had weekly NO₂ above the California annual outdoor standard of 30 ppb.

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.

PM2.5 and Trace Elements in Underground Shopping Districts in the Seoul Metropolitan Area, Korea

We measured PM_2.5 in 41 underground shopping districts (USDs) in the Seoul metropolitan area from June to November 2017, and associated 18 trace elements to determine the sources and assess the respiratory risks. The PM_2.5 concentrations were 18.0 ± 8.0 μg/m³ inside USDs, which were lower than 25.2 ± 10.6 μg/m³ outside. We identified five sources such as indoor miscellanea, soil dust, vehicle exhaust/cooking, coal combustion, and road/subway dust, using factor analysis. Almost 67% of the total trace element concentration resulted from soil dust. Soil dust contribution increased with the number of stores because of fugitive dust emissions due to an increase in passers-by. Vehicle exhaust/cooking contribution was higher when the entrances of the USDs were closed, whereas coal combustion contribution was higher when the entrances of the USDs were open. Although miscellanea and coal combustion contributions were 3.4% and 0.7%, respectively, among five elements with cancer risk, Cr and Ni were included in miscellanea, and Pb, Cd, and As were included in coal combustion. The excess cancer risk (ECR) was the highest at 67 × 10^-6 for Cr, and the ECR for Pb was lower than 10^-6, a goal of the United States Environmental Protection Agency for hazardous air pollutants.

Assessment of Indoor Benzene and Its Alkyl Derivatives Concentrations in Offices Belonging to University of Technology (Poland)

Indoor air contamination in office rooms is regarded as one of the most important issues in the protection of workers’ health, because contaminants, even those occurring at low concentrations, can cause health problems for the office staff in view of the long exposure time. This paper presents the results of measurements of benzene and its alkyl derivatives (toluene, ethylbenzene, xylenes, styrene, and 1,3,5-trimethylbenzene)—known indicators of human exposure to volatile organic compounds (VOCs) in the air in newly renovated offices at University of Technology (Upper Silesia, Poland). Monthly samples of indoor and outdoor air were collected during the years 2018–2019 by passive methods and analyzed by thermal desorption-gas chromatography with flame ionization detector (TD-GC/FID). In the first month of measurements average concentrations of the sum of five VOCs under consideration was 127.7 µg/m3, then in subsequent months between 15.1 µg/m3 to 87.3 µg/m3. The average concentration of carcinogenic benzene was below 1.5 μg/m3. Toluene had the highest concentration among studied VOCs, accounting for as high as 60% and 84% of the total indoor and outdoor VOCs, respectively. High indoor-to-outdoor (I/O) ratios for ethylbenzene (7.1), m,p-xylene (9.8), and styrene (12.5) indicate the dominant role of indoor sources.

Indoor Exposure to Selected Air Pollutants in the Home Environment: A Systematic Review

(1) Background: There is increasing awareness that the quality of the indoor environment affects our health and well-being. Indoor air quality (IAQ) in particular has an impact on multiple health outcomes, including respiratory and cardiovascular illness, allergic symptoms, cancers, and premature mortality. (2) Methods: We carried out a global systematic literature review on indoor exposure to selected air pollutants associated with adverse health effects, and related household characteristics, seasonal influences and occupancy patterns. We screened records from six bibliographic databases: ABI/INFORM, Environment Abstracts, Pollution Abstracts, PubMed, ProQuest Biological and Health Professional, and Scopus. (3) Results: Information on indoor exposure levels and determinants, emission sources, and associated health effects was extracted from 141 studies from 29 countries. The most-studied pollutants were particulate matter (PM_2.5 and PM₁₀); nitrogen dioxide (NO₂); volatile organic compounds (VOCs) including benzene, toluene, xylenes and formaldehyde; and polycyclic aromatic hydrocarbons (PAHs) including naphthalene. Identified indoor PM_2.5 sources include smoking, cooking, heating, use of incense, candles, and insecticides, while cleaning, housework, presence of pets and movement of people were the main sources of coarse particles. Outdoor air is a major PM_2.5 source in rooms with natural ventilation in roadside households. Major sources of NO₂ indoors are unvented gas heaters and cookers. Predictors of indoor NO₂ are ventilation, season, and outdoor NO₂ levels. VOCs are emitted from a wide range of indoor and outdoor sources, including smoking, solvent use, renovations, and household products. Formaldehyde levels are higher in newer houses and in the presence of new furniture, while PAH levels are higher in smoking households. High indoor particulate matter, NO₂ and VOC levels were typically associated with respiratory symptoms, particularly asthma symptoms in children. (4) Conclusions: Household characteristics and occupant activities play a large role in indoor exposure, particularly cigarette smoking for PM_2.5, gas appliances for NO₂, and household products for VOCs and PAHs. Home location near high-traffic-density roads, redecoration, and small house size contribute to high indoor air pollution. In most studies, air exchange rates are negatively associated with indoor air pollution. These findings can inform interventions aiming to improve IAQ in residential properties in a variety of settings.

Emissions of VOCs, SVOCs, and mold during the construction process: Contribution to indoor air quality and future occupants' exposure

Building materials and human activities are important sources of contamination indoors, but little information is available regarding contamination during construction process which could persist during the whole life of buildings. In this study, six construction stages on two construction sites were investigated regarding the emissions of 43 volatile organic compounds (VOCs), 46 semi-volatile organic compounds (SVOCs), and the presence of 4 genera of mold. Results show that the future indoor air quality does not only depend on the emissions of each building product but that it is also closely related to the whole implementation process. Mold spore measurements can reach 1400 CFU/m³ , which is particularly high compared with the concentrations usually measured in indoor environments. Relatively low concentrations of VOCs were observed, in relation to the use of low emissive materials. Among SVOCs analyzed, some phthalates, permethrin, and hydrocarbons were found in significant concentrations upon the delivery of building as well as triclosan, suspected to be endocrine disruptor, and yet prohibited in the treatment of materials and construction since 2014. As some regulations exist for VOC emissions, it is necessary to implement them for SVOCs due to their toxicity.

Children's Respiratory Infections in Tianjin Area, China: Associations with Home Environments and Lifestyles

Children spend most of their indoors time at home, which may have substantial influence on their health. We conducted a cross-sectional study in the Tianjin area, China to quantify the incidence of respiratory infections among children, and its association with home environments and lifestyles. The lifetime-ever incidences of croup, pneumonia and ear infection among children aged 0-8 in Tianjin area was 9.2%, 28.7% and 11.6%, respectively. The incidence of common cold infections more than twice per year was 31.3%. Home environments and lifestyles included strong risk factors for childhood respiratory infections. Perceived dry air had the greatest association with childhood common colds (population attributable fraction (PAF = 15.0%). Modern floor covering had the greatest association with croup (PAF = 14.7%) and ear infection (PAF = 34.5%), while infrequent bedding sun-curing had the greatest association with pneumonia (PAF = 18.7%). Condensation (a proxy of poor ventilation) accounted for 12.2% of the incidence of croup (PAF = 12.2%) and frequent common colds (PAF = 8.4%). Our findings indicate that factors related to "modern" home environments and lifestyles are risks for childhood respiratory infections. Modifying such factors might reduce the incidence of respiratory infections among children.

Volatile organic compounds in 169 energy-efficient dwellings in Switzerland

Exposure to elevated levels of certain volatile organic compounds (VOCs) in households has been linked to deleterious health effects. This study presents the first large-scale investigation of VOC levels in 169 energy-efficient dwellings in Switzerland. Through a combination of physical measurements and questionnaire surveys, we investigated the influence of diverse building characteristics on indoor VOCs. Among 74 detected compounds, carbonyls, alkanes, and alkenes were the most abundant. Median concentration levels of formaldehyde (14 μg/m³ ), TVOC (212 μg/m³ ), benzene (<0.1 μg/m³ ), and toluene (22 μg/m³ ) were below the upper exposure limits. Nonetheless, 90% and 50% of dwellings exceeded the chronic exposure limits for formaldehyde (9 μg/m³ ) and TVOC (200 μg/m³ ), respectively. There was a strong positive correlation among VOCs that likely originated from common sources. Dwellings built between 1950s and 1990s, and especially, those with attached garages had higher TVOC concentrations. Interior thermal retrofit of dwellings and absence of mechanical ventilation system were associated with elevated levels of formaldehyde, aromatics, and alkanes. Overall, energy-renovated homes had higher levels of certain VOCs compared with newly built homes. The results suggest that energy efficiency measures in dwellings should be accompanied by actions to mitigate VOC exposures as to avoid adverse health outcomes.

Indoor Air Quality Analysis of Newly Built Houses

Recently, people have become increasingly aware of potential health issues related to indoor environments. In this study, we measure the concentrations of various volatile organic compounds, carbonyl compounds, and semi-volatile organic compounds, as well as the ventilation rates, in 49 new houses with light-gauge steel structures one week after completion. The proper indoor air quality of new residential environments can be ensured by characterizing people’s exposure to certain chemicals and assessing future risks. Our results show that the concentrations of the measured compounds were lower than the guideline values set by the Ministry of Health, Labour and Welfare of Japan, and would continue to decrease. However, we observed that unregulated compounds, assumed to be substitutes for regulated solvents, contributed substantially to the total volatile organic compounds. To reduce indoor chemical exposure risks, the concentrations of these unregulated compounds should also be minimized. In addition, their sources need to be identified, and manufacture and use must be monitored. We believe it is important to select low-emission building materials for reducing residents’ exposure to indoor chemicals.

Ambient air pollution in gastrointestinal endoscopy unit

BACKGROUND

The gastrointestinal endoscopy unit is frequently exposed to gastrointestinal gas expelled from patients and electrocoagulated tissue through carbonation. This can be potentially harmful to the health of not only the healthcare personnel but also patients who undergo endoscopy. This study aimed to measure the air quality in the endoscopy unit.

METHODS

We measured indoor air quality indices (CO₂, total volatile organic compounds (VOCs), PM_2.5, NO₂, CO, and ozone) using portable passive air quality monitoring sensors in the procedural area, recovery area, and cleansing-of-equipment area, at 1-min intervals for 1 week, and the type and number of endoscopic procedures were recorded.

RESULTS

CO₂, PM_2.5, NO₂, and ozone levels were the highest in the cleansing area, followed by the procedural and recovery areas, and VOC level was highest in the procedural area. The proportion of poor-quality level of CO₂ and VOCs was highest in the procedural area and that of NO₂ was highest in the cleansing area. The proportion of tolerable to poor-quality (exceeding acceptable level) level of CO₂ and total VOCs in the procedural area was 26% and 19.2% in all measurement times, respectively. The proportion of tolerable to poor-quality level of NO₂ in the cleansing area of the endoscopy unit was 32.1% in all measurement times. Multivariate analyses revealed that tolerable to poor-quality (exceeding acceptable level) level of VOCs was associated with the number of endoscopic procedures (odds ratio, 1.79; 95% confidence interval, 1.42-2.27) and PM_2.5 level (1.27, 1.12-1.44). Moreover, tolerable to poor-quality level of CO₂ was associated with the number of colonoscopy (5.35, 1.19-24.02), especially with electrocoagulation procedures (24.31, 1.31-452.44) in the procedural area.

CONCLUSIONS

Healthcare personnel and patients who undergo endoscopy are frequently exposed to ambient air pollution. Health-related protective strategies for ambient air pollution in the endoscopy unit are warranted. CLINICALTRIALS.

GOV REGISTRATION NUMBER

NCT03724565.

Effects of Legal Regulation on Indoor Air Quality in Facilities for Sensitive Populations - A Field Study in Seoul, Korea

Facilities for sensitive populations have increased in Korea; and its indoor air quality (IAQ) was strictly regulated by the Korean government compared to other facilities. However, merely public facilities on certain level of total floor area were lawfully regulated. This study aims to characterize the indoor environment at facilities for sensitive populations in Korea and investigate the effects of legal regulation on IAQ throughout the duration of 1 year. Sixty facilities for sensitive populations were investigated. Particulate matter (PM₁₀), nitrogen dioxide (NO₂), carbon dioxide (CO₂), carbon monoxide (CO), total bacteria count (TBC), total volatile organic compound (TVOC), formaldehyde (HCHO), radon (Rn), ozone (O₃), asbestos, fine particulate matter (PM_2.5), and volatile organic compounds (VOCs) were target pollutants. As a result, none of the rooms' concentration of CO, NO₂, O₃, Rn, asbestos, and VOCs exceeded the Korean Standard of Indoor Air Quality, while some rooms' concentration of other pollutants exceeded the KSIAQ. Statutory facilities had lower indoor pollutant concentrations and exceedance rates due to efficient ventilation system and the lack of kitchen location within the building, as opposed to non-statutory facilities. In addition, the VOCs had significant differences depending on the number of years it took for the building to be constructed. To reduce the indoor pollutants concentrations, efficient ventilation systems should be installed while controlling the main sources of pollutants. In addition, construction and remodeling using eco-friendly materials should be considered. The standards of IAQ for small size facilities should be included in the KSIAQ in the future.

Sources of volatile organic compounds in suburban homes in Shanghai, China, and the impact of air filtration on compound concentrations

Air pollution in China is an ongoing concern, with subsets of the population (e.g., asthmatic children) especially susceptible to the associated health effects. In addition, people spend the majority of their time indoors, where pollutant composition may differ from the better characterized ambient environment. Although volatile organic compounds (VOCs) present health risks and have high concentrations indoors, their sources have not been thoroughly quantified in typical homes in suburban China. Similarly lacking is an understanding of how well a purifier with high efficiency particulate air and activated carbon filters can remove VOCs in a real-world setting in China. In this study, we a) quantified total VOCs (TVOC) and 900 + individual VOCs in 20 homes in China, b) identified potential sources of VOCs, and c) evaluated impacts of filtration. We used non-negative matrix factorization, a variable reduction technique, to identify sources. TVOC and individual compounds had higher concentrations indoors than outdoors (mean [range] indoors, filtration with pre-filter only: 302 [56-793] μg m-3; outdoors, entire study: 92 [26-629] μg m-3), indicating prevalent sources indoors. Many compounds detected have not, to our knowledge, been measured in homes in China. Some compounds (e.g., octanal, heptanal, ⍺-cedrene) were specific to the indoor environment, a few were ubiquitous (e.g., acetaldehyde, formaldehyde), and others were detected infrequently. These compounds may originate from consumer products, solvents, vehicle emissions, a hexane source, wooden products, and cooking. Filtration may improve air quality indoors by lowering concentrations of some VOCs, and, specifically, contributions related to solvents and consumer products.

Impact on lung function among children exposed to home new surface materials: The seven Northeastern Cities Study in China

We conducted a cross-sectional study to investigate the associations between recent home renovation exposure and lung function in children. We randomly recruited 7326 school children residing in 24 districts from seven cities in northeastern China. We collected information about home renovations from parents using a questionnaire and lung function measurements from children using spirometer recordings gathered by trained professionals and expressed as the forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), maximal mid-expiratory flow (MMEF), and peak expiratory flow (PEF). We identified higher odds of diminished lung function among these with home renovation in the previous 2 years compared to those without home renovation in the previous 2 years, for FVC (odds ratios [ORs] = 1.84 [95%CI: 1.58, 2.15]; FEV1: ORs = 2.82 [95%CI: 2.36, 3.36]; PEF: ORs = 1.51 [95%CI: 1.24, 1.83]; and MMEF: ORs = 1.90 [95%CI: 1.60, 2.24]). The associations were stronger among children exposed to new polyvinyl chloride (PVC) flooring compared to children exposed to other surface materials. Our results were consistent throughout the analysis of each type of renovation materials. In conclusion, recent home renovation exposure was associated with poor lung function among children. Strategies to protect home owners and their families from respiratory hazards during and after renovation are required.

Ambient air pollution in gastrointestinal endoscopy unit; rationale and design of a prospective study

BACKGROUND

A gastrointestinal endoscopy unit is frequently exposed to gastrointestinal gas expelled from patients and electrocoagulated tissue through carbonation for the treatment of gastrointestinal neoplasms or hemostasis of gastrointestinal bleeding. This can be potentially harmful to the health of not only the healthcare personnel but also patients who undergo endoscopic examinations. However, there has been scarce data on air quality in the endoscopy unit. This study aimed to measure the air quality in the gastrointestinal endoscopy unit.

METHODS

This is a prospective study using conventional portable passive air quality monitoring sensors in the gastrointestinal endoscopy unit. We will check the 6 main indoor air quality indices, as well as the atmospheric temperature, pressure, and humidity in the endoscopy unit of a single hospital in Korea. These indices are as follows: carbon dioxide (CO2), total volatile organic compounds (VOCs), particulate matter that has a diameter of <2.5 μm, nitrogen dioxide (NO2), carbon monoxide (CO), and ozone. The indices will be checked in the endoscopy unit, including the procedural area, recovery area, and area for disinfection and cleansing of equipment, at 1-minute intervals for at least 1 week, and the type and number of endoscopic procedures will also be recorded. The primary outcome of this study is to determine whether the air quality indices exceed safety thresholds and whether there is any association between ambient air pollution and the type and number of endoscopic procedures.

CONCLUSION

The results of this study will provide evidence for health-related protective strategies for medical practitioners and patients in the endoscopy unit.

The basic roles of indoor plants in human health and comfort

Humans have a close relationship with nature, and so integrating the nature world into indoor space could effectively increase people's engagement with nature, and this in turn may benefit their health and comfort. Since people spend 80-90% of their time indoors, the indoor environment is very important for their health. Indoor plants are part of natural indoor environment, but their effect on the indoor environment and on humans has not been quantified. This review provides a comprehensive summary of the role and importance of indoor plants in human health and comfort according to the following four criteria: photosynthesis; transpiration; psychological effects; and purification. Photosynthesis and transpiration are important mechanisms for plants, and the basic functions maintaining the carbon and oxygen cycles in nature. Above all have potential inspiration to human's activities that people often ignored, for example, the application of solar panel, artificial photosynthesis, and green roof/facades were motivated by those functions. Indoor plants have also been shown to have indirect unconscious psychological effect on task performance, health, and levels of stress. Indoor plants can act as indoor air purifiers, they are an effective way to reduce pollutants indoor to reduce human exposure, and have been widely studied in this regard. Indoor plants have potential applications in other fields, including sensing, solar energy, acoustic, and people's health and comfort. Making full use of various effects in plants benefit human health and comfort.

Making the Case for "Whole System" Approaches: Integrating Public Health and Housing

Housing conditions have been an enduring focus for public health activity throughout the modern public health era. However, the nature of the housing and health challenge has changed in response to an evolution in the understanding of the diverse factors influencing public health. Today, the traditional public health emphasis on the type and quality of housing merges with other wider determinants of health. These include the neighbourhood, community, and "place" where a house is located, but also the policies which make access to a healthy house possible and affordable for everyone. Encouragingly, these approaches to policy and action on housing have the potential to contribute to the "triple win" of health and well-being, equity, and environmental sustainability. However, more effective housing policies (and in public health in general) that adopt more systemic approaches to addressing the complex interactions between health, housing, and wider environment are needed. This paper illustrates some of the key components of the housing and health challenge in developed countries, and presents a conceptual model to co-ordinate activities that can deliver the "triple win." This is achieved by offering a perspective on how to navigate more effectively, inclusively and across sectors when identifying sustainable housing interventions.

Phytoremediation of Formaldehyde from Indoor Environment by Ornamental Plants: An Approach to Promote Occupants Health

Background

Formaldehyde is a common hazardous indoor air pollutant which recently raised public concerns due to its well-known carcinogenic effects on human. The aim of this study was to investigate a potted plant-soil system ability in formaldehyde removal from a poor ventilated indoor air to promote dwellers health.

Methods

For this purpose, we used one of the common interior plants from the fern species (Nephrolepis obliterata), inside a Plexiglas chamber under controlled environment. Entire plant removal efficiency and potted soil/roots contribution were determined by continuously introducing different formaldehyde vapor concentrations to the chamber (0.6-11 mg/m³) each over a 48-h period. Sampling was conducted from inlet and outlet of the chamber every morning and evening over the study period, and the average of each stage was reported.

Results

The results showed that the N. obliterata plant efficiently removed formaldehyde from the polluted air by 90%-100%, depending on the inlet concentrations, in a long time exposure. The contribution of the soil and roots for formaldehyde elimination was 26%. Evaluation of the plant growing characteristics showed that the fumigation did not affect the chlorophyll content, carotenoid, and average height of the plant; however, a decrease in the plant water content was observed.

Conclusions

According to the results of this study, phytoremediation of volatile organic compound-contaminated indoor air by the ornamental potted plants is an effective method which can be economically applicable in buildings. The fern species tested here had high potential to improve interior environments where formaldehyde emission is a health concern.

Indoor levels of volatile organic compounds and formaldehyde from emission sources at elderly care centers in Korea

The objective of this study is to characterize indoor and outdoor levels of volatile organic compounds (VOCs) and formaldehyde (HCHO) and identify indoor emission sources in thirty elderly care centers (ECCs) located in the Seoul metropolitan city and Gyeonggi province in Korea. Air monitoring samples from indoor and outdoor environments were collected from January to December in 2007. Statistical analyses of indoor and outdoor VOCs and HCHO levels in three rooms (a bedroom, living, and dining rooms) of each ECC were performed, and these were compared to identify environmental factors associated with an increase of indoor pollution levels. Total volatile organic compounds (TVOC) levels were significantly (p<0.05) different between indoor (230.7±1.7 μg/m3) and outdoor (137.8±1.9 μg/m3) environments, with an I/O ratio of 1.67. The indoor HCHO level (20.1±1.6 μg/m3) was significantly (p<0.05) higher than the outdoor level (8.1±1.9 μg/m3), with an I/O ratio of 2.48. Indoor VOCs and HCHO levels in the bedrooms were significantly (p<0.05) higher than those in the living and dining rooms. Furthermore, indoor levels of VOCs and HCHO at ECCs were significantly (p<0.05) different depending on environmental factors such as the use of carpet, paint, and wooden furniture. In multiple regression analysis, indoor VOCs and HCHO levels at ECCs were significantly (p<0.05) correlated with two micro-environmental factors: the use of carpet and paint. This study confirmed that indoor VOCs and HCHO levels were significantly higher than those in outdoor environments. These air pollutants were mainly emitted from indoor sources, such as carpet, paint, and construction materials at the ECCs in Korea.

Phytoremediation of VOCs from indoor air by ornamental potted plants: A pilot study using a palm species under the controlled environment

Volatile organic compounds (VOCs) in indoor air have recently raised public concern due to their adverse health effects. One of hazardous VOC is Formaldehyde which can cause sensory irritation and induce nasopharyngeal cancer. The aim of this study was to investigate potted plant-soil system ability in formaldehyde removal from indoor air. We applied one of common interior plant from the palm species, Chamaedorea elegans, inside a chamber under the controlled environment. Entire plant, growing media and roots contribution in formaldehyde were evaluated by continuously introduction of different concentrations of formaldehyde into the chamber (0.66-16.4 mg m^-3) each over a 48-h period. Our findings showed that the plant efficiently removed formaldehyde from polluted air by 65-100%, depending on the inlet concentrations, for a long time exposure. A maximum elimination capacity of 1.47 mg/m². h was achieved with an inlet formaldehyde concentration of 14.6 mg m^-3. The removal ratio of areal part to pot soil and roots was 2.45:1 (71%: 29%). The plants could remove more formaldehyde in light rather than dark environment. Concentrations up to 16.4 mg m^-3 were not high enough to affect the plants growth. However, a trivial decrease in chlorophyll content, carotenoid and water content of the treated plants was observed compared to the control plants. Thus, the palm species tested here showed high tolerance and good potential of formaldehyde removal from interior environments. Therefore, phytoremediation of VOCs from indoor air by the ornamental potted plants is an effective method which can be economically applicable in homes and offices.

Indoor air quality in energy-efficient dwellings: Levels and sources of pollutants

Worldwide, public policies are promoting energy-efficient buildings and accelerating the thermal renovation of existing buildings. The effects of these changes on the indoor air quality (IAQ) in these buildings remain insufficiently understood. In this context, a field study was conducted in 72 energy-efficient dwellings to describe the pollutants known to be associated with health concerns. Measured parameters included the concentrations of 19 volatile organic compounds and aldehydes, nitrogen dioxide, particulate matter (PM_2.5 ), radon, temperature, and relative humidity. The air stuffiness index and night-time air exchange rate were calculated from the monitored carbon dioxide (CO₂ ) concentrations. Indoor and outdoor measurements were performed at each dwelling during 1 week in each of the two following seasons: heating and non-heating. Moreover, questionnaires were completed by the occupants to characterize the building, equipment, household, and occupants' habits. Perspective on our results was provided by previous measurements made in low-energy European dwellings. Statistical comparisons with the French housing stock and a pilot study showed higher concentrations of terpenes, that is, alpha-pinene and limonene, and hexaldehyde in our study than in previous studies. Alpha-pinene and hexaldehyde are emitted by wood or wood-based products used for the construction, insulation, decoration, and furnishings of the dwellings, whereas limonene is more associated with discontinuous sources related to human activities.

Direct and potential risk assessment of exposure to volatile organic compounds for primary receptor associated with solvent consumption

Rapid development of industrial production has stimulated the growth of consumption of raw and auxiliary materials including organic paints, among which volatile organic compounds (VOCs) are proved harmful to the population who inhale the polluted air based on epidemiologic studies. Therefore, new types of environment-friendly paints were developed to replace solvent-based paints (SBPs). Nevertheless, new types of paints containing VOCs failed to replace SBPs entirely due to certain disadvantages. Hence, five kinds of paints were employed in simulation experiments to assess the health risk of primary receptor including three kinds of water-based paints (WBPs) and two kinds of SBPs. Conclusions showed that mean TVOC concentration in breathing zone of primary receptor ranged from 9.5 to 13.6 mg/m³ and 3.4 × 10³ to 1.4 × 10⁴ mg/m³ for WBPs and SBPs, respectively. Assessments of non-cancer risk concluded that nearly one third quantified compounds exceeded corresponding thresholds for WBPs, and the maximum risk value was 101.33; for SBPs, the maximum risk value reached 50760.20, and twenty-two compounds exceeded the reference limits. The calculation of cancer risk values showed that seventeen compounds were higher than acceptable limit amongst which 1,2-dibromoethane had maximum values of 1.27 × 10^-2 to 3.24 × 10^-2 for WBPs; for SBPs, all quantified compounds exceeded the acceptable limit, and 82.61% VOCs were distributed in a scope larger than 1 × 10^-3. Additionally, a removal efficiency of 60% was considered for primary receptor with personal protective equipment, and subsequent results confirmed its inability of lowering the risk resulted from hazardous VOCs. The calculated potential health risk could be applied to estimate the total health risk for both primary and secondary receptor based on consumed materials. The finding suggested that WBPs could improve VOCs exposure condition and reduce the direct and potential health risk significantly for primary receptor, although they might dissatisfy acceptable limit.

Factors Effecting the Total Volatile Organic Compound (TVOC) Concentrations in Slovak Households

Thirty five Slovak households were selected for an investigation of indoor environmental quality. Measuring of indoor air physical and chemical factors and a questionnaire survey was performed during May 2017. The range of permissible operative temperature was not met in 11% of objects. Relative humidity met the legislative requirements in all monitored homes. Concentrations of total volatile organic compounds (TVOCs) were significantly higher in the apartments than in the family houses. The average TVOC levels in the apartments and family houses were 519.7 µg/m³ and 330.2 µg/m³, respectively. Statistical analysis confirmed the effect of indoor air temperature, relative humidity and particulate matter (PM_0.5 and PM₁) on the levels of TVOCs. Higher TVOC levels were observed also in homes where it is not a common practice to open windows during cleaning activities. Other factors that had a statistically significant effect on concentrations of volatile organic compounds were heating type, attached garage, location of the apartment within residential building (the floor), as well as number of occupants. Higher TVOC concentrations were observed in indoor than outdoor environment, while further analysis showed the significant impact of indoor emission sources on the level of these compounds in buildings. The questionnaire study showed a discrepancy between objective measurement and subjective assessment in the household environment, and pointed to insufficient public awareness about volatile organic compounds (VOCs).

Field-to-laboratory analysis of clay wall coatings as passive removal materials for ozone in buildings

Ozone reacts readily with many indoor materials, as well as with compounds in indoor air. These reactions lead to lower indoor than outdoor ozone concentrations when outdoor air is the major contributor to indoor ozone. However, the products of indoor ozone reactions may be irritating or harmful to building occupants. While active technologies exist to reduce indoor ozone concentrations (i.e, in-duct filtration using activated carbon), they can be cost-prohibitive for some and/or infeasible for dwellings that do not have heating, ventilating, and air-conditioning systems. In this study, the potential for passive reduction of indoor ozone by two different clay-based interior surface coatings was explored. These coatings were exposed to occupied residential indoor environments and tested bimonthly in environmental chambers for quantification of ozone reaction probabilities and reaction product emission rates over a 6-month period. Results indicate that clay-based coatings may be effective as passive removal materials, with relatively low by-product emission rates that decay rapidly within 2 months.

Exhaust ventilation in attached garages improves residential indoor air quality

Previous research has shown that indoor benzene levels in homes with attached garages are higher than homes without attached garages. Exhaust ventilation in attached garages is one possible intervention to reduce these concentrations. To evaluate the effectiveness of this intervention, a randomized crossover study was conducted in 33 Ottawa homes in winter 2014. VOCs including benzene, toluene, ethylbenzene, and xylenes, nitrogen dioxide, carbon monoxide, and air exchange rates were measured over four 48-hour periods when a garage exhaust fan was turned on or off. A blower door test conducted in each garage was used to determine the required exhaust fan flow rate to provide a depressurization of 5 Pa in each garage relative to the home. When corrected for ambient concentrations, the fan decreased geometric mean indoor benzene concentrations from 1.04 to 0.40 μg/m³ , or by 62% (P<.05). The garage exhaust fan also significantly reduced outdoor-corrected geometric mean indoor concentrations of other pollutants, including toluene (53%), ethylbenzene (47%), m,p-xylene (45%), o-xylene (43%), and carbon monoxide (23%) (P<.05) while having no impact on the home air exchange rate. This study provides evidence that mechanical exhaust ventilation in attached garages can reduce indoor concentrations of pollutants originating from within attached garages.

VOC characteristics and inhalation health risks in newly renovated residences in Shanghai, China

BACKGROUND

Exposure to indoor VOCs is expected to link to a variety of negative health outcome. The popularity of decorations and refurbishment in homes in China has given rise to indoor elevated VOC levels, potentially posing health threats to residents.

METHODS

In this study, concentrations of 101 VOC compounds and associated health risks were investigated in newly renovated homes in Shanghai. The potential excess inhalation health risks from home exposure of 17 health-related VOCs were estimated by the Inhalation Unit Risk (IUR) and Reference Concentration (RfC) proposed by US EPA. Monte Carlo simulation and sensitivity analysis were used to assess the uncertainty associated with the estimates of health risks.

RESULTS

The dominant groups by mass concentration were oxygenated VOCs (o-VOCs), aromatics, alkanes and halogenated VOCs (x-VOCs) .12 VOCs with IARC's confirmed or probable carcinogens ratings were detected with a >60% detection frequency in the total samples. The mean concentrations of BTEX (benzene, toluene, m/p-xylene, o-xylene, ethylbenzene) were 2.32μg/m³, 200.13μg/m³, 39.56μg/m³, 32.59μg/m³ and 26.33μg/m³ respectively, generally higher than those in older homes reported in previous studies except benzene. The mean concentration of methylene chloride (47.43μg/m³) and 1,2-dichloroethane (33.83μg/m³) were noticeably higher than the levels reported in previous studies in Hong Kong, Japan and Canada. Whereas the mean concentration of 1,4-dichlorobenzene (5.53μg/m³) were similar to the results of Canadian national survey but lower than those in Japan. The concentrations of 1,2-dichloroethane, 1,4-dichlorobenzene, and methylene chloride, ethylbenzene presented a mean cancer risk at 7.39×10^-6, 1.95×10^-6, 1.62×10^-6, 1.04×10^-6 respectively, above the US EPA proposed acceptable risk level of 1×10^-6. Sensitivity analyses indicated that the VOC exposure concentration have a greater impact than the IUR values on the risk assessment.

CONCLUSION

This study highlights the characteristics of VOCs in recently renovated homes and has implications for the adverse health effects that result from exposure to chlorinated hydrocarbons in indoor air.

Characterization of the variation of carbonyl compounds concentrations before, during, and after the renovation of an apartment at Niterói, Brazil

The present work reports the variation of 31 carbonyl compounds (CC) in an apartment located at Niterói City, Rio de Janeiro State, Brazil. Eight sampling campaigns were conducted through a 1-year period, and three areas (living room, kitchen, and bedroom) were evaluated before, during, and after the renovation activities and reoccupation of the apartment. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, and the hydrazones were analyzed using rapid resolution liquid chromatography with UV detection. The lowest total concentration of CC (19.0 ± 1.5 μg m(-3)) was found before the renovation when the apartment was empty, but door varnishing resulted in highest contamination of the apartment (1386 ± 384 μg m(-3)); however, an important dispersion of CC was observed in the subsequent sampling (148 ± 1.8 μg m(-3)). After apartment reoccupation, the indoor contamination seemed to depend on the routine activities taken there, such as household product use and cooking activities, but apparently, local temperature increase favored the vaporization of the volatile CC from the building materials in the apartment. As far as we are concerned, this is the first study comparing the concentrations of 31 CC in residential areas before, during, and after renovation activities taken in Brazil.

Do time-averaged, whole-building, effective volatile organic compound (VOC) emissions depend on the air exchange rate? A statistical analysis of trends for 46 VOCs in U.S. offices

We used existing data to develop distributions of time-averaged air exchange rates (AER), whole-building 'effective' emission rates of volatile organic compounds (VOC), and other variables for use in Monte Carlo analyses of U.S. offices. With these, we explored whether long-term VOC emission rates were related to the AER over the sector, as has been observed in the short term for some VOCs in single buildings. We fit and compared two statistical models to the data. In the independent emissions model (IEM), emissions were unaffected by other variables, while in the dependent emissions model (DEM), emissions responded to the AER via coupling through a conceptual boundary layer between the air and a lumped emission source. For 20 of 46 VOCs, the DEM was preferable to the IEM and emission rates, though variable, were higher in buildings with higher AERs. Most oxygenated VOCs and some alkanes were well fit by the DEM, while nearly all aromatics and halocarbons were independent. Trends by vapor pressure suggested multiple mechanisms could be involved. The factors of temperature, relative humidity, and building age were almost never associated with effective emission rates. Our findings suggest that effective emissions in real commercial buildings will be difficult to predict from deterministic experiments or models.

An assessment of air quality reflecting the chemosensory irritation impact of mixtures of volatile organic compounds

We present a method to assess the air quality of an environment based on the chemosensory irritation impact of mixtures of volatile organic compounds (VOCs) present in such environment. We begin by approximating the sigmoid function that characterizes psychometric plots of probability of irritation detection (Q) versus VOC vapor concentration to a linear function. First, we apply an established equation that correlates and predicts human sensory irritation thresholds (SIT) (i.e., nasal and eye irritation) based on the transfer of the VOC from the gas phase to biophases, e.g., nasal mucus and tear film. Second, we expand the equation to include other biological data (e.g., odor detection thresholds) and to include further VOCs that act mainly by "specific" effects rather than by transfer (i.e., "physical") effects as defined in the article. Then we show that, for 72 VOCs in common, Q values based on our calculated SITs are consistent with the Threshold Limit Values (TLVs) listed for those same VOCs on the basis of sensory irritation by the American Conference of Governmental Industrial Hygienists (ACGIH). Third, we set two equations to calculate the probability (Qmix) that a given air sample containing a number of VOCs could elicit chemosensory irritation: one equation based on response addition (Qmix scale: 0.00 to 1.00) and the other based on dose addition (1000*Qmix scale: 0 to 2000). We further validate the applicability of our air quality assessment method by showing that both Qmix scales provide values consistent with the expected sensory irritation burden from VOC mixtures present in a wide variety of indoor and outdoor environments as reported on field studies in the literature. These scales take into account both the concentration of VOCs at a particular site and the propensity of the VOCs to evoke sensory irritation.

Formaldehyde and acetaldehyde exposure mitigation in US residences: in-home measurements of ventilation control and source control

Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasing ventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h(-1), increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED)-certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h(-1), and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration was 33 μg/m(3) and 22 μg/m(3) for low-VOC homes and 45 μg/m(3) and 30 μg/m(3) for conventional.

Compilation and analysis of types and concentrations of airborne chemicals measured in various indoor and outdoor human environments

The main purpose of this article is to summarize and illustrate the results of a literature search on the types, levels, relative concentrations, concentration spread of individual chemicals, and number of airborne compounds (mostly volatile organic compounds, VOCs) that have been found, measured, and reported both indoors and outdoors. Two broad categories of indoor environments are considered: (1) home/school, and (2) commercial spaces. Also, two categories of outdoor environments are considered: (1) non-industrial and (2) industrial (the latter represented by the vicinity of a pig farm and the vicinity of an oil refinery). The outcome is presented as a series of graphs and tables containing the following statistics: geometric mean, arithmetic mean, median, standard deviation, variance, standard error, interquartile distance, minimum value, maximum value, and number of data (data count) for the air concentration of each reported compound in a given environment. A Supplementary Table allows interested readers to match each single value included in this compilation with its corresponding original reference.

Gaseous chemical compounds in indoor and outdoor air of 602 houses throughout Japan in winter and summer

A nationwide survey of indoor air quality in Japan was conducted using four types of diffusive samplers. Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 602 houses throughout Japan in winter and summer. Four kinds of diffusive samplers were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid impregnated silica for basic gases. These samplers are small and lightweight and do not require a power source, hence, it was possible to obtain a large number of air samples via mail from throughout Japan. Almost all compounds in indoor air were present at higher levels in summer than in winter. In particular, formaldehyde, toluene, and ammonia were strongly dependent on temperature, and their levels increased with temperature. The nitrogen dioxide concentration in indoor air particularly increased only during winter and was well correlated with the formic acid concentration (correlation coefficient=0.959). Ozone concentrations in indoor air were extremely low compared with the outdoor concentrations. Ozone flowing from outdoor air may be decomposed quickly by chemical compounds in indoor air; therefore, it is suggested that the indoor/outdoor ratio of ozone represents the ventilation of the indoor environment.

Domestic exposure to volatile organic compounds in relation to asthma and allergy in children and adults

Over the past decades, the prevalence of asthma, allergic disease and atopy has increased significantly and in parallel with the increased use of products and materials emitting volatile organic compounds (VOCs) in the indoor environment. The purpose of this review is to examine the evidence of the relationship between quantitatively measured domestic exposure to VOCs and allergic diseases and allergy in children and adults. Sources, potential immune-inflammatory mechanisms and risks for development and severity of asthma and allergy have been addressed. Available evidence is based on studies that have mainly used observational designs of variable quality. Total, aromatic, aliphatic, microbial VOCs and aldehydes have been the most widely investigated VOC classes, with formaldehyde being the most commonly examined single compound. Overall, the evidence is inadequate to draw any firm conclusions. However, given indicative evidence from a few high-quality studies and significant potential for improvements in asthma outcomes in those with established disease, there is a need to consider undertaking further investigation of the relationship between domestic VOC exposure and asthma/allergy outcomes that should encompass both high-quality, robust observational studies and ultimately clinical trials assessing the impact of interventions that aim to reduce VOC exposure in children and adults with asthma.

Home renovation, family history of atopy, and respiratory symptoms and asthma among children living in China

OBJECTIVES

To investigate the association of indoor air pollution with the respiratory health of children, we evaluated the associations of children's respiratory symptoms with asthma and recent home renovation.

METHODS

We conducted a cross-sectional survey in a school recruitment sample of 31,049 children aged 2 to 14 years in 25 districts of 7 cities of northeast China in 2008-2009. The children's parents completed standardized questionnaires characterizing the children's histories of respiratory symptoms and illness, recent home renovation information, and other associated risk factors.

RESULTS

The effects of home renovation in the past 2 years were significantly associated with cough, phlegm, current wheeze, doctor-diagnosed asthma, and current asthma. The associations we computed when combining the status of home renovation and family history of atopy were higher than were those predicted from the combination of the separate effects. However, the interactions between home renovation and family history of atopy on a multiplicative scale were not statistically significant (P>.05).

CONCLUSIONS

Home renovation is associated with increases in the prevalence of respiratory symptoms and asthma in children. The effects of different renovation materials on child respiratory health should be studied further.

Indoor air quality and thermal comfort in temporary houses occupied after the Great East Japan Earthquake

Thermal conditions and indoor concentrations of aldehydes, volatile organic compounds (VOCs), and NO2 were investigated in 19 occupied temporary houses in 15 temporary housing estates constructed in Minamisoma City, Fukushima, Japan. The data were collected in winter, spring, and summer in January to July 2012. Thermal conditions in temporary log houses in the summer were more comfortable than those in pre-fabricated houses. In the winter, the indoor temperature was uncomfortably low in all of the houses, particularly the temporary log houses. Indoor air concentrations for most aldehydes and VOCs were much lower than the indoor guidelines, except for those of p-dichlorobenzene, acetaldehyde, and total VOCs. The indoor p-dichlorobenzene concentrations exceeded the guideline (240 μg/m(3)) in 18% of the temporary houses, and the 10(-3) cancer risk level (91 μg/m(3)) was exceeded in winter in 21% due to use of moth repellents by the occupants. Indoor acetaldehyde concentrations exceeded the guideline (48 μg/m(3) ) in about half of the temporary houses, likely originating from the wooden building materials. Indoor NO2 concentrations in the temporary houses were significantly higher in houses where combustion heating appliances were used (0.17 ± 0.11 ppm) than in those where they were not used (0.0094 ± 0.0065 ppm).

PRACTICAL IMPLICATIONS

In the winter, log-house-type temporary houses are comfortable in terms of humidity, dew condensation, and fungi based on the results of questionnaires and measurements, whereas pre-fabricated temporary houses are more comfortable in terms of temperature. In the summer, log-house-type temporary houses are comfortable in terms of temperature and humidity. More comfortable temporary housing in terms of temperature and humidity year-round is needed. Indoor air concentrations of p-dichlorobenzene and NO2 were quite high in some temporary houses due to occupants’ activities, such as use of moth repellents and combustion heating appliances. The government should provide recommendations for safe use of temporary houses by occupants.

Characterization and risk assessment of exposure to volatile organic compounds in apartment buildings in Harbin, China

This study analyzed the risk of exposure to volatile organic compounds (VOCs) in the apartment buildings (including bedrooms, living rooms, kitchens and study rooms) in Harbin, China. The concentration of total VOCs in bedrooms showed the lowest value with an average of 482.6 mg/m(3). 32.33 % of total measured VOCs correspond to aromatic hydrocarbons. The major chemical forms of the identified VOCs in other 3 types of rooms were alcohols which contributed to 30.66 % (in living rooms), 36.55 % (in kitchens) and 35.43 % (in study rooms) separately. Formaldehyde was the pollutant of highest concern given its high chronic toxic and carcinogenic risk levels according to the health assessment. Other pollutants of concern for human heal risks were benzene and naphthalene. The non-cancer risk by the exposure to naphthalene ranged from 2.39 to 2.80 in 4 target groups, which is more than 1.0 considered as a hazarded level to human health.

Volatile aromatic hydrocarbons (VAHs) in residential indoor air in Brisbane, Australia

Volatile aromatic hydrocarbons (VAHs: benzene, toluene, ethylbenzene, mp-xylene, o-xylene, styrene, naphthalene) in residential indoor air in Brisbane, Australia were measured in 32 houses. The total VAHs (TVAHs) levels ranged between 2 and 137μg/m(3) and were lower than the most of the houses in the literature data. The VAHs were believed to originate from heat insulation systems, building material products as well motor vehicles but naphthalene and styrene originated from other sources. Internal garages had concentrations which are higher than the indoor air by 25-50% due to the presence of motor vehicles and may be a major source of indoor VAHs. However indoor concentrations are higher than that in the outdoor ambient air. The age of the house was found to be negatively related to VAHs concentrations in the houses with the half-life of TVAH at approximately 13years. The concentration levels of benzene, toluene, ethylbenzene and styrene are well below the guideline values set by agencies from Hong Kong, Japan, Germany and the WHO while the concentration level of naphthalene in one house exceeded the guideline value from Germany.

Respiratory viral infections and effects of meteorological parameters and air pollution in adults with respiratory symptoms admitted to the emergency room

Background

Respiratory viral infections (RVIs) are the most common causes of respiratory infections. The prevalence of respiratory viruses in adults is underestimated. Meteorological variations and air pollution are likely to play a role in these infections.

Objectives

The objectives of this study were to determine the number of emergency visits for influenza-like illness (ILI) and severe acute respiratory infection (SARI) and to evaluate the association between ILI/SARI, RVI prevalence, and meteorological factors/air pollution, in the city of Porto Alegre, Brazil, from November 2008 to October 2010.

Methods

Eleven thousand nine hundred and fifty-three hospitalizations (adults and children) for respiratory symptoms were correlated with meteorological parameters and air pollutants. In a subset of adults, nasopharyngeal aspirates were collected and analyzed through IFI test. The data were analyzed using time-series analysis.

Results

Influenza-like illness and SARI were diagnosed in 3698 (30·9%) and 2063 (17·7%) patients, respectively. Thirty-seven (9·0%) samples were positive by IFI and 93 of 410 (22·7%) were IFI and/or PCR positive. In a multivariate logistic regression model, IFI positivity was statistically associated with absolute humidity, use of air conditioning, and presence of mold in home. Sunshine duration was significantly associated with the frequency of ILI cases. For SARI cases, the variables mean temperature, sunshine duration, relative humidity, and mean concentration of pollutants were singnificant.

Conclusions

At least 22% of infections in adult patients admitted to ER with respiratory complaints were caused by RVI. The correlations among meteorological variables, air pollution, ILI/SARI cases, and respiratory viruses demonstrated the relevance of climate factors as significant underlying contributors to the prevalence of RVI.

Indoor air quality, air exchange rates, and radioactivity in new built temporary houses following the Great East Japan Earthquake in Minamisoma, Fukushima

This study measured air exchange rates, indoor concentrations of aldehydes and volatile organic compounds (VOCs), and radioactivity levels at 19 temporary houses in different temporary housing estate constructed in Minamisoma City following the Great East Japan Earthquake. The 19 surveyed houses represented all of the companies assigned to construct temporary houses in that Minamisoma City. Data were collected shortly after construction and before occupation, from August 2011 to January 2012. Mean air exchange rates in the temporary houses were 0.28/h, with no variation according to housing types and construction date. Mean indoor concentrations of formaldehyde, acetaldehyde, toluene, ethylbenzene, m/p-xylene, o-xylene, styrene, p-dichlorobenzene, tetradecane, and total VOCs (TVOCs) were 29.2, 72.7, 14.6, 6.35, 3.05, 1.81, 7.29, 14.3, 8.32, and 901 μg/m(3), respectively. The levels of acetaldehyde and TVOCs exceeded the indoor guideline (48 μg/m(3)) and interim target (400 μg/m(3)) in more than half of the 31 rooms tested. In addition to guideline chemicals, terpenes (α-pinene and d-limonene) and acetic esters (butyl acetate and ethyl acetate) were often detected in these houses. The indoor radiation levels measured by a Geiger-Müller tube (Mean: 0.22 μSv/h) were lower than those recorded outdoors (Mean: 0.42 μSv/h), although the shielding effect of the houses was less than for other types of buildings.

Longitudinal variations in indoor VOC concentrations after moving into new apartments and indoor source characterization

This study examined the indoor concentrations of a wide range of volatile organic compounds (VOCs) in currently built new apartments every month over a 24-month period and the source characteristics of indoor VOCs. The indoor total VOC (TVOC) concentrations exhibited a decreasing tendency over the 24-month follow-up period. Similar to TVOCs, the median indoor concentrations of 33 of 40 individual VOCs (all except for naphthalene and six halogenated VOCs) revealed decreasing tendencies. In contrast, the indoor concentrations of the six halogenated VOCs did not reveal any definite trend with time. Moreover, the indoor concentrations of those halogenated VOCs were similar to the outdoor concentrations, suggesting the absence of any notable indoor sources of halogenated VOCs. For naphthalene (NT), the indoor concentrations were significantly higher than the outdoor concentrations, suggesting the presence of indoor NT source(s). The floor/wall coverings (39 %) were the most influential indoor source of indoor VOCs, followed by household cleaning products (32 %), wood paneling/furniture (17 %), paints (7 %), and moth repellents (5 %).