TVOC Concentrations Research Articles

Law and features of TVOC and Formaldehyde pollution in urban indoor air

There are several categories of indoor air pollutants. Organic pollutants are the most common ones. This study chooses TVOC and Formaldehyde, two of the typical pollutants, as indicators of evaluating household indoor air pollution and improves the TVOC concentration prediction model through the samples of indoor air taken from 3122 households. This study also categorizes and explains the features of household indoor air pollution based on the TVOC and Formaldehyde models as well as a large amount of sample measurement. Moreover, this study combines the TVOC model with the Formaldehyde model to calculate and verify the critical values of each type of indoor air pollution. In this study, indoor air pollution is categorized into three types: decoration pollution, consumption pollution and transition pollution. During the first 12 months after decoration, decoration pollution is the primary pollution type, both TVOC and Formaldehyde are highly concentrated while sometimes seriously over the standard. Pollutants mainly come from volatile sources. After the first 12 month but before 24 months the indoor air pollution is transition pollution. Both decoration materials and human activates affect the indoor air quality. 24 months after decoration, it transits into consumption pollution. In this stage, the main pollutants come from combustion sources, and concentration of pollutants fluctuates with the appearance and disappearance of the sources.

Volatile organic compounds (VOCs) emissions of wood-based panels coated with nanoparticles modified water based varnish

The VOCs emissions of veneered particleboards coated with nanoparticles modified waterborne polyurethane varnish were investigated in this study. For the improvement of nanoparticles dispersion in waterborne polyurethane varnish, the surface of the nanoparticles was modified with KH550 silane coupling agent. VOCs emissions of coating panels containing various nanoparticles were evaluated with small-scale chamber method. The effect of nano TiO2, montmorillonite (MMT) and the mixture of them in varnish on VOCs degradation of wood-based panels were discussed and compared to the original varnish coating panels without nanoparticles herein. The results showed that treatment of nanoparticles with KH550 improves nanoparticles dispersion, and the modified waterborne polyurethane varnish used for wood-based panels finishing improved VOCs emissions. Various nanoparticles additions in varnish coating panels result in different degradation capacity on VOCs emission. After UV irradiation, the equilibrium concentrations of TVOC emitted from nanoparticles modified varnish coating panels were 21.05–41.57 % lower than of control panel. In addition, aldehydes and ketones compounds were found to exhibit good reduction.

Evaluation of Purification Effect of Intelligent Air Purifier in the Pathology Department

Objective: Evaluate the application effect of the intelligent air purifier through the analysis of monitoring results before and after the pathology department air purification. Method: Make 30 days of real time, dynamic monitoring to the air quality of the pathology department conventional technical support division before and after purification by “eagle eye” environment monitor, record 100 times of monitoring data of the work time and make analysis. Result: The concentration of formaldehyde, TVOC, CO2 and CO before purification are 1.21 ± 0.80 mg/m3, 0.21 ± 0.46 mg/m3, 0.06 ± 0.01%, 3.28 ± 1.49 mg/m3, while after purification which respectively are 0.06 ± 0.01 mg/m3, 0.00 ± 0.00 mg/m3, 0.06 ± 0.01%, 0.71 ± 0.33 mg/m3. Conclusion: Through the real time monitoring to the air quality of the pathology department after using the intelligent air purifier, we find that the concentration of formaldehyde, TVOC,CO and PM 2.5, PM 10 are markedly reduced (P<0.05), those were in the safety level, it can make sure the staff health by using the air purifier.

Assessment of Selected Interior Flooring Materials On Indoor Air Quality

Indoor air quality depends on many factors, such as temperature, humidity, odours or presence of pollutants. A lot of materials used in the buildings, either as structural materials or as furnishings, are mostly the indoor air pollution sources. Interior surface materials are generally accepted as the main TVOCs emissions source. The chemical and sensory assessment of selected interior flooring materials on indoor air quality is presented within the paper. Air acceptability, odour intensity and TVOCs concentration for selected interior flooring materials (polyvinyl chloride flooring, tongue flooring and acrylic based flooring) were tested. The chemical and sensory measurements were performed in a glass test chamber. The parameters were monitored by different air change rate per hour. Chemical measurement is based on the absorbed TVOCs gas chromatography analysis. The panellists of sensory assessment consist of group of responsible persons from 20 to 38 years (35% smokers). Each approached subject assesses the odour intensity and the air acceptability. The improving of sensory assessment with increasing the air change rate was not confirmed. Conversely, the unfavourable results are improving with increasing air change rate, in the case of materials with significantly indented and porous surface.

신축목조주택의 실내공기질 특성 및 관련요인 분석

The purpose of this research is to analyze characteristics and related factors of IAQ (Indoor Air Quality) in newly built wooden houses by measuring pre and post occupancy. The subjects were five wooden houses which were built with similar materials and completed from July to December 2013. Measuring factors were TVOC, HCHO, PM10, , CO, indoor temperature, and relative humidity. As result of pre occupancy measuring, houses that revealed lowest TVOC concentration or HCHO concentration were satisfied with the standard for newly built apartment houses. Therefore, IAQ by wooden structures is considered to be in good condition. However, in cases of partial value exceeded standard, reason is analyzed to be materials of molding, wrapping doors, built-in closet, or kitchen furniture, etc. rather than structure materials. Most PM10 concentration level showed slightly below the standard for occupied multi-use facilities. Remaining of construction dust was considered to be reason. As result of post occupancy measuring, every value except of one subject`s TVOC concentration was lower than pre occupancy, explaining importance of natural ventilation.

Airborne volatile organic compounds in urban and industrial locations in four developing countries

Volatile organic compounds (VOCs) represent an important class of air pollutants, however their concentration levels in developing countries have scarcely been reported in literature. Therefore, concentration levels of 60 VOCs were determined at 27 urban and industrial locations in seven different cities in Ethiopia, Vietnam, the Philippines and Bangladesh between 2011 and 2014. Active sampling using Tenax TA as a sorbent was employed followed by TD-GC-MS analysis using internal standard calibration. It was found that TVOCs concentration levels in Dhaka, Bangladesh (arithmetic mean: 343 and 399 μg/m3 for urban and industrial campaign, respectively) were more than 10 times higher when compared to TVOCs levels observed in Mekelle, Ethiopia. ∑BTEX concentration at street sites ranges from 36 μg/m3 in Mekelle, to 100 and 250 μg/m3 in Hanoi, Vietnam and Dhaka, Bangladesh, respectively. The indoor to outdoor concentration ratios were found to be dependent on the country, type of environment, VOC compound and outdoor reference location. The highest Ozone Formation Potential (OFP, 2150 μg/m3), calculated from the same set of seven aromatic VOCs, was obtained at the street site in Dhaka. This OFP value is a factor three and four times higher than the OFP value observed at the street sites in Hanoi, and Manila, respectively. Finally, the Cumulative Cancer Risk (CCR) calculated for four carcinogenic VOCs ranged from 97 × 10−6 in urban Mekelle to 299 × 10−6 in urban Dhaka. This work provides for the first time comparisons of CCR in urban and industrial environments in the selected developing countries.

Gaseous pollutants on rural and urban nursery schools in Northern Portugal

Indoor air quality in nursery schools is different from other schools and this has been largely ignored, particularly in rural areas. Urban and rural nursery schools have different environmental characteristics whose knowledge needs improvement. Thus, this study aimed to evaluate continuously the concentrations of CO2, CO, NO2, O3, CH2O and total VOC in three rural nursery schools and one urban, being the only one comparing urban and rural nurseries with continuous measurements, thus considering occupation and non-occupation periods. Regarding CO2, urban nursery recorded higher concentrations (739–2328 mg m−3) than rural nurseries (653–1078 mg m−3). The influence of outdoor air was the main source of CO, NO2 and O3 indoor concentrations. CO and NO2 concentrations were higher in the urban nursery and O3 concentrations were higher in rural ones. CH2O and TVOC concentrations seemed to be related to internal sources, such as furniture and flooring finishing and cleaning products.

Pollution Characteristic of VOCs during Straw Burning Period in Chengdu, China

Volatile organic compounds (VOCs) were analyzed in straw burning period and non-straw burning period in the center of Chengdu city. The results showed that the concentrations of TVOC during straw burning were significantly higher than that in the non-straw burning period in Chengdu. The main components were alkanes, aromatic hydrocarbons and esters in straw burning period while aromatic hydrocarbons, alkanes, esters, aldehydes and ketones as the main contents in the period of non-straw burning. The correlation of TVOC, SO2, NO2, PM10, PM2.5, CO, O3 and the API index was discussed and the NOX-sensitive of photochemical reaction type was determined by the ratio of TVOC / NO2 during straw burning period.

Indoor air quality in passive and conventional new houses in Sweden

The indoor environment was evaluated in 20 new passive houses and 21 new conventionally built houses during the 2012/2013 and 2013/2014 heating seasons. Temperature, relative humidity (RH), the concentrations of NO2, ozone, formaldehyde, volatile organic compounds (VOC) and viable microbiological flora were measured. Air exchange rates (AER) were estimated from the CO2 concentrations measured in the bedrooms. The median AER was slightly higher in the passive houses than in the conventional ones (0.68 h−1 vs. 0.60 h−1). The median concentrations in the passive and the conventional buildings were 10 and 12 μg/m3 for NO2, 9.7 and 11 μg/m3 for ozone, 11 and 16 μg/m3 for formaldehyde, and 270 and 150 μg/m3 for TVOC, respectively. Significant differences in the TVOC and formaldehyde concentrations between the two groups of buildings indicated substantial sources of TVOC present in the passive houses, while sources of formaldehyde may have been more pronounced in the conventional houses. In contrast to the passive houses, the indoor microbiological flora indicated possible mould or moisture problems in six (29%) of the conventionally built houses. When compared with the results previously reported for the Swedish housing stock, AERs and NO2 concentrations were significantly higher in both groups of newly built buildings, while formaldehyde concentrations were significantly lower in the passive houses. TVOC concentrations were not significantly different from those reported for the housing stock, although the most abundant individual VOCs were present mostly at higher concentrations in the new buildings.

ANALYSIS OF VOCs IN THE INDOOR ENVIRONMENT

Volatile organic compounds have been studied over recent years in many countries. However, construction processes, building materials, building types and the methods used for the collection and analysis of VOCs vary from one country to another. At the same time constant technical and scientific progress has brought new materials that can emit completely different VOCs than older materials. Building materials represent significant source of organic compounds’ emissions and we are in direct contact with these compounds at work, school or home every day. Short-term or long-term exposure to these substances can bring many health problems. Therefore, this study is focused to determine the current state of occurrence and concentrations level of VOCs. The studied building is located in eastern Slovakia. The results were compared with the guide values of other countries, because there are no guideline values for TVOC concentrations and limits are set only for a small amount of VOCs in Slovakia. The results from this study demonstrated that flooring installation together with painting caused the highest contribution to the TVOC levels in the indoor air of studied apartment. On the other hand, high levels of TVOC were not found after furnishing.

VOCs and Particulate Pollution due to Incense Burning in Temples, China

To investigate the air pollution due to incenses burning, formaldehyde, respirable particulate (PM10) and 12 kinds of VOCs (volatile organic compounds) and TVOC were measured and analyzed at different sampling sites in Temples located in Shanxi Province and Beijing, China. The main results showed that incense burning significantly elevates the concentrations of formaldehyde, benzene, toluene, xylene, and TVOC. The total concentrations of aldehyde compounds including formaldehyde, furfural, etc. varied ranging from 0.05 to 1.22mg/m3 and formaldehyde was the most abundant. The formaldehyde concentrations higher than 0.10mg/m3 in Beijing Temple were harmful to human health. Benzene and toluene concentrations exceeded the recommended levels 0.05mg/m3 by ‘WHO’, respectively. The number concentrations of PM10 in a Shanxi Temple were the highest and PM10 in all the Temples were greater than that outside Temples. It indicates that incense burning was the main source for formaldehyde, VOCs and respirable particle. The health risk for Buddhist priest, staffs and worshipers in the Temples exposed to incense burning for long time may be increased.

국내 선박용 도료의 VOCs함량분포 및 오존생성기여도에 관한 연구

Abstract In this research, a few paints in the shipyard were selected and analyzed for the component and ozone productionin marine paint using TVOC and GC/FID, ozone generation index(MIR, POCP) to establish measures of VOC s ef-fectively. The concentrations of TVOC ranged between approximately 300~400 g/L and 400~500 g/L, respecti-vely and these showed 37% of whole. Our results indicated that the main constituents of marine paints were m,p,o-xylene(49%), ethyl benzene(10%), toluene(8%) and 2-propanol(5%). It was also found that xylene concentrationhave relatively higher impact on ozone generation. The types of paints were also investigated for their potentials.The biggest contributor was the 1 Pack Finish paint. The rest is, in their contributing order, 1 Pack Finish paint, 2pack Finish paint, Anti-fouling paint, 2 Pack A/C paint, Ballast paint and 1 Pack A/C paint. Key words : Paint solvents, VOC, TVOC, Marine paint *Corresponding author.Tel : +82-(0)2-940-5497, E-mail : yooks@kw.ac.kr

A Survey of Indoor Air Quality in Archives

Archives are the indoor spaces which have the special purpose of preservation of records. But the values of the Korean standard about air quality in archives are not realistic. Furthermore there are no measured data for analysis about indoor air quality level of archives. So, we measured indoor air quality of three archives on site for evaluation standard level. We carried comparative analyses of the Korean standard and ISO-11799 the international standard for review of the adequacy of standard. SO₂, O₃ and CO concentration levels in archives were much lower(about 10% level) than the Korean standard. PM10 and Formaldehyde concentrations were about 40% level of the Korean standard, and NOx was about 65% level. But, TVOCs concentration was exceed the standard value(400 μg/m³). Temperature and Relative humidity level were far off the standard range. SO₂, O₃ and CO standard values should be improved to the international standard levels for realistic regulation values. NOx and Formaldehyde regulation values in the Korean standard should be gradually improved to the international standard levels, and their concentration management methods should be researched at the same time. As TVOCs concentration levels were exceed the standard, it is necessary to control the indoor air quality more strictly. The thermo-hygrostat must be installed to control temperature and humidity in archives.

Evaluation of indoor environmental quality conditions in elementary schools׳ classrooms in the United Arab Emirates

This study presents findings of indoor environmental quality (IEQ) investigations conducted in elementary schools׳ classrooms in the United Arab Emirates (UAE). Average TVOC, CO2, O3, CO, and particle concentrations measured in the classrooms were 815µg/m3, 1605ppm, 0.05ppm, 1.16ppm, and 1730µg/m3, respectively. Whereas, local authority known as Dubai Municipality recommended 300µg/m3, 800ppm, 0.06ppm, 9ppm, and 150–300µg/m3 for TVOC, CO2, O3, CO, and particle, respectively. Dubai Municipality recommended temperature and relative humidity (RH) levels of 22.5°C to 25.5°C and 30%–60%, respectively. Average temperature and RH levels measured in the classrooms were 24.5°C and 40.4%, respectively. Average sound level in the classrooms was 24dB greater than recommended sound level limit of 35dB. Six (6) classrooms had average lux levels in the range of 400–800lux. Two (2) classrooms had average lux levels in the range of 100–200lux. The remaining classrooms had lux levels around the recommended 300lux. High occupancy density was observed in majority of the studied classrooms. Observations during walkthrough investigations could be used to explain measured IEQ data. Poor IEQ conditions in the studied classrooms highlight the need for further research investigation to understand how poor classrooms׳ IEQ condition could influence students׳ health, comfort, attendance rate, and academic performance.

Seasonal and Temporal Variation of Volatile Organic Compounds (VOCs) Pollution in Isolo Industrial Areas of Lagos State, Southwestern-Nigeria

Spatial and temporal variations of volatile organic compounds in ambient air in Isolo Industrial Area during May, 2010 to April, 2011 are presented. The results were analysed in other to present information about the detailed nature of air quality situation in the sampled areas. The air samples were collected by passive sampler (ORSA 5). The air samplers were exposed to a height of 1.5 - 2.0 m and sampling was carried out four times a month for a period of 12 months. The adsorbed VOCs were desorbed with carbondisulphide (CS 2 ) and the solution analysed using Gas Chromatography (GC) fitted with Flame Ionization Detector (FID). The results from analysis of the air samples collected showed that twenty (26) VOCs were captured. There is a significant difference (P < 0.05) between the levels of VOCs in Isolo. Despite comparatively higher concentrations of VOCs at the studied sites, there is a significant difference in the spatial distribution. At lower wind speed, the VOCs concentrations tend to increase and become uniformly distributed around the industrial Areas. The temporal distribution shows a decrease in ambient concentrations of VOCs from May to July due to Atmospheric (dilution)/wash down by rain. The results of two-way factor ANOVA analysis of the monthly average of total volatile organic compounds revealed that there is significant difference (P < 0.05) in seasonal and temporal variations of TVOC concentrations in the studied areas. The meteorological parameters showed significant correlations with the ambient concentrations of VOCs. The principal component analysis revealed that the major sources of VOCs in Isolo are mainly Anthropogenic and four (4) factors were identified as sources of VOCs in the studied area with Industrial and emissions from traffic dominating. Key words: Significant, Pollution, Spatial, Anthropogenic, Temporal

Indoor air quality (IAQ) assessment in a multistorey shopping mall by high-spatial-resolution monitoring of volatile organic compounds (VOC)

In order to assess indoor air quality (IAQ), two 1-week monitoring campaigns of volatile organic compounds (VOC) were performed in different areas of a multistorey shopping mall. High-spatial-resolution monitoring was conducted at 32 indoor sites located in two storehouses and in different departments of a supermarket. At the same time, VOC concentrations were monitored in the mall and parking lot area as well as outdoors. VOC were sampled at 48-h periods using diffusive samplers suitable for thermal desorption. The samples were then analyzed with gas chromatography-mass spectrometry (GC-MS). The data analysis and chromatic maps indicated that the two storehouses had the highest VOC concentrations consisting principally of terpenes. These higher TVOC concentrations could be a result of the low efficiency of the air exchange and intake systems, as well as the large quantity of articles stored in these small spaces. Instead, inside the supermarket, the food department was the most critical area for VOC concentrations. To identify potential emission sources in this department, a continuous VOC analyzer was used. The findings indicated that the highest total VOC concentrations were present during cleaning activities and that these activities were carried out frequently in the food department. The study highlights the importance of conducting both high-spatial-resolution monitoring and high-temporal-resolution monitoring. The former was able to identify critical issues in environments with a complex emission scenario while the latter was useful in interpreting the dynamics of each emission source.

Development of a Coil-Shape Photocatalysis-Plasma Synergistic Reactor for a Practical and Long-Term Usable Air-Cleaner

A novel air-cleaner with a coil-shape photocatalysis-plasma synergistic reactor was developed. The air-cleaner showed 95% ± 1% reduction of a TVOCs concentration in tobacco smoke at “single-pass” condition. Air-purification activity of the air-cleaner was stably-maintained after the treatment of 12,000 cigarettes of tobacco smoke.

Impact of indoor surface material on perceived air quality

The material combination impact on perceived indoor air quality for various surface interior materials is presented in this paper. The chemical analysis and sensory assessments identifies health adverse of indoor air pollutants (TVOCs). In this study, emissions and odors from different common indoor surface materials were investigated in glass test chamber under standardized conditions. Chemical measurements (TVOC concentration) and sensory assessments (odor intensity, air acceptability) were done after building materials exposure to standardized conditions. The results of the chemical and sensory assessment of individual materials and their combinations are compared and discussed within the paper. The using possibility of individual material surface sorption ability was investigated. The knowledge of targeted sorption effects can be used in the interior design phase. The results demonstrate the various sorption abilities of various indoor materials as well as the various sorption abilities of the same indoor material in various combinations.

Measurement of temperature, relative humidity and concentrations of CO, CO2 and TVOC during cooking typical Chinese dishes

This study investigated the effect of exhaust hood during cooking case-study dishes of Eight Cuisines of China. Parameters were measured of hood idle or working mode included the continuous measurements of air temperature, air relative humidity and generations of CO, CO2 and TVOC of the breathing zone. Different from former researchers, we found the cooking techniques are not the reason that causes serious pollution. The emissions of CO and CO2 not only were related to the cooking time, but also occurred largely as a result of the burning of the gas; however, the generation of TVOC attributed in large part to using the seasonings, ingredients and the behavior of marinating. The maximum increase of TVOC concentration during cooking dishes with cooking wine was at least 526.7–543% higher than the others. Besides, the behavior of marinating would cause at least 80–556.3% increase. Compared to hood idle mode, the decrement of maximum increases of temperature, CO2 and TVOC concentrations were 7–50.29%, 6.6–379.5% and 136.6–4211.6% respectively in hood working mode. The situation became very complicated for relative humidity and CO concentration. Even with an exhaust hood, there was still a significant high value of contaminant levels in the breathing zone, especially in the beginning phase of the cooking process (200s). The values of test parameters finally reached a stable value after a certain period of time. This time of hood idle mode was almost the double of the hood working mode.

Airborne Measurements of Ozone and Its Precursors over Yeosu-Gwangyang Industrial Areas in the Southern Coast of Korea

The purpose of this study is to understand distributional characteristics in the atmospheric concentrations of <TEX>$O_3$</TEX> and its precursors based on data taken at the southern Korean coast. The average <TEX>$O_3$</TEX> concentration in the high altitude was found to range from 32.3 to 90.8 ppb with a maximum concentration of 132 ppb. The ambient <TEX>$O_3$</TEX> concentration was high at altitudes of 1000 m and 500 m above the southern sea near Gwangyang Bay and an industrial area containing emission sources. The daily mean concentrations of <TEX>$NO_y$</TEX> and CO were 6.7-24.2 ppb and 0.152-0.487 ppm, respectively. During the aerial measurement period, the highest mean concentration of <TEX>$O_3$</TEX> was observed on June 1. The aerial measurement results showed that the maximum ozone concentration was observed to be 132 ppb in the high altitude the southernmost part of Yeosu. The measurement of vertical wind fields in the air indicated that <TEX>$O_3$</TEX> formed in the southernmost part of Yeosu was transported by strong southwesterly winds to the northeast of Gwangyang Bay. This led to a ground <TEX>$O_3$</TEX> concentration of over 100 ppb in Jinju, the northeastern part of Gwangyang Bay. On August 9, when the maximum <TEX>$O_3$</TEX> concentration was 50 ppb, the measurement results showed that <TEX>$O_3$</TEX> concentrations were relatively low compared to other days. In particular, low <TEX>$NO_2$</TEX> and TVOC concentrations were observed, both of which serve to form <TEX>$O_3$</TEX> in photochemical reactions.