Formaldehyde and acetaldehyde exposure and risk characterization in California early childhood education environments

Little information is available about air quality in early childhood education (ECE) facilities. We collected single‐day air samples in 2010–2011 from 40 ECE facilities serving children ≤6 years old in California and applied new methods to evaluate cancer risk in young children. Formaldehyde and acetaldehyde were detected in 100% of samples. The median (max) indoor formaldehyde and acetaldehyde levels (μg/m³) were 17.8 (48.8) and 7.5 (23.3), respectively, and were comparable to other California schools and homes. Formaldehyde and acetaldehyde concentrations were inversely associated with air exchange rates (Pearson r = ?0.54 and ?0.63, respectively; P < 0.001). The buildings and furnishings were generally >5 years old, suggesting other indoor sources. Formaldehyde levels exceeded California 8‐h and chronic Reference Exposure Levels (both 9 μg/m³) for non‐cancer effects in 87.5% of facilities. Acetaldehyde levels exceeded the U.S. EPA Reference Concentration in 30% of facilities. If reflective of long‐term averages, estimated exposures would exceed age‐adjusted ‘safe harbor levels’ based on California's Proposition 65 guidelines (10^?5 lifetime cancer risk). Additional research is needed to identify sources of formaldehyde and acetaldehyde and strategies to reduce indoor air levels. The impact of recent California and proposed U.S. EPA regulations to reduce formaldehyde levels in future construction should be assessed.     

Chemical exposures from upholstered furniture with various flame retardant technologies

Upholstered furniture is often manufactured with polyurethane foam (PUF) containing flame retardants (FRs) to prevent the risk of a fire and/or to meet flammability regulations, however, exposure to certain FRs and other chemicals have been linked to adverse health effects. This study developed a new methodology for evaluating volatile organic compound (VOC) and FR exposures to users of upholstered furniture by simulating use of a chair in a controlled exposure chamber and assessing the health significance of measured chemical exposure. Chairs with different fire-resistant technologies were evaluated for VOC and FR exposures via inhalation, ingestion, and dermal contact exposure routes. Data show that VOC exposure levels are lower than threshold levels defined by the US and global indoor air criteria. Brominated FRs were not detected from the studied chairs. The organophosphate FRs added to PUF were released into the surrounding air (0.4 ng/m³) and as dust (16 ng/m²). Exposure modeling showed that adults are exposed to FRs released from upholstered furniture mostly by dermal contact and children are exposed via dermal and ingestion exposure. Children are most susceptible to FR exposure/dose (2 times higher average daily dose than adults) due to their frequent hand to mouth contact.     

室内建筑材料VOC散发模型及应用

目前VOC散发模型主要有基于环境舱实验的经验模型和基于质传递理论的理论模型。对这两类模型及其应用作了简要回顾，指出研究中存在的问题，如VOC散发机理研究欠深入，模型的适用性单一，建模作了较大简化等。     

Occupational exposure and health risks of volatile organic compounds of hotel housekeepers: Field measurements of exposure and health risks

Hotel housekeepers represent a large, low-income, predominantly minority, and high-risk workforce. Little is known about their exposure to chemicals, including volatile organic compounds (VOCs). This study evaluates VOC exposures of housekeepers, sources and factors affecting VOC levels, and provides preliminary estimates of VOC-related health risks. We utilized indoor and personal sampling at two hotels, assessed ventilation, and characterized the VOC composition of cleaning agents. Personal sampling of hotel staff showed a total target VOC concentration of 57 ± 36 µg/m³ (mean ± SD), about twice that of indoor samples. VOCs of greatest health significance included chloroform and formaldehyde. Several workers had exposure to alkanes that could cause non-cancer effects. VOC levels were negatively correlated with estimated air change rates. The composition and concentrations of the tested products and air samples helped identify possible emission sources, which included building sources (for formaldehyde), disinfection by-products in the laundry room, and cleaning products. VOC levels and the derived health risks in this study were at the lower range found in the US buildings. The excess lifetime cancer risk (average of 4.1 × 10⁻⁵) still indicates a need to lower exposure by reducing or removing toxic constituents, especially formaldehyde, or by increasing ventilation rates.     

Health risk assessment of personal inhalation exposure to volatile organic compounds in Tianjin, China

Volatile Organic Compounds (VOCs) exposure can induce a range of adverse human health effects. To date, however, personal VOCs exposure and residential indoor and outdoor VOCs levels have not been well characterized in the mainland of China, less is known about health risk of personal exposure to VOCs. In this study, personal exposures for 12 participants as well as residential indoor/outdoor, workplace and in vehicle VOCs concentrations were measured simultaneously in Tianjin, China. All VOCs samples were collected using passive samplers for 5 days and were analyzed using Thermal Desorption GC-MS method. U.S. Environmental Protect Agency's Inhalation Unit Risks were used to calculate the inhalation cancer health risk. To assess uncertainty of health risk estimate, Monte Carlo simulation and sensitivity analysis were implemented. Personal exposures were greater than residential indoor exposures as expected with the exception of carbon tetrachloride. Exposure assessment showed modeled and measured concentrations are statistically linearly correlated for all VOCs (P < 0.01) except chloroform, confirming that estimated personal exposure using time-weighted model can provide reasonable estimate of personal inhalation exposure to VOCs. Indoor smoking and recent renovation were identified as two major factors influencing personal exposure based on the time-activity pattern and factor analysis. According to the cancer risk analysis of personal exposure, benzene, chloroform, carbon tetrachloride and 1,3-butadiene had median upper-bound lifetime cancer risks that exceeded the U.S. EPA benchmark of 1 per one million, and benzene presented the highest median risks at about 22 per one million population. The median cumulative cancer risk of personal exposure to 5 VOCs was approximately 44 per million, followed by indoor exposure (37 per million) and in vehicle exposure (36 per million). Sensitivity analysis suggested that improving the accuracy of exposure measurement in further research would advance the health risk assessment.     

Assessment of ventilation and indoor air pollutants in nursery and elementary schools in France

The aim of this study was to characterize the relationship between Indoor Air Quality (IAQ) and ventilation in French classrooms. Various parameters were measured over one school week, including volatile organic compounds, aldehydes, particulate matter (PM_2.5 mass concentration and number concentration), carbon dioxide (CO₂), air temperature, and relative humidity in 51 classrooms at 17 schools. The ventilation was characterized by several indicators, such as the air exchange rate, ventilation rate (VR), and air stuffiness index (ICONE), that are linked to indoor CO₂ concentration. The influences of the season (heating or non‐heating), type of school (nursery or elementary), and ventilation on the IAQ were studied. Based on the minimum value of 4.2 l/s per person required by the French legislation for mechanically ventilated classrooms, 91% of the classrooms had insufficient ventilation. The VR was significantly higher in mechanically ventilated classrooms compared with naturally ventilated rooms. The correlations between IAQ and ventilation vary according to the location of the primary source of each pollutant (outdoor vs. indoor), and for an indoor source, whether it is associated with occupant activity or continuous emission.     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

Total Volatile Organic Concentrations in 2700 Personal,Indoor; and Outdoor Air Samples collected in the US EPA Team Studies

Concentrations of total volatile organic compounds (TVOC) exceeding 1 mg/m³ have been implicated in the Sick Building Syndrome. Very few measurements of TVOC have been made in homes and buildings in the United States. However, stored gas chromatography-mass spectrometry (GC-MS) data on 12-hour average values of individual VOCs from 750 homes and 10 buildings were available from EPA's Total Exposure Assessment Methodology (TEAM) Studies (1981-88). An initial study to determine the feasibility of obtaining a TVOC value from stored GC/MS data showed that TVOC estimates could be obtained with adequate precision. Therefore TVOC values were calculated for about 2700 personal, indoor, and outdoor air samples collected in the TEAM Studies. More than half of the personal and indoor air samples had TVOC levels exceeding 1 mg/m³, compared to only about 10% of the outdoor air samples. However, these calculated values may not be directly comparable with values determined using different sampling and analytical techniques. Nonetheless, since all samples were collected on Tenax cartridges, which (like all sorbents) adsorb only a portion of the organic chemicals in the air, these values are likely to be underestimates of the total volatile organic loading.     

A Review and a Limited Comparison of Methods for Measuring Total Volatile Organic Compounds in Indoor Air

Numerous methods attempt to measure the combined concentrations of volatile organic compounds (VOCs) in indoor air as total VOCs (TVOC). This paper reviews TVOC methods recently presented in the literature and at an international conference on indoor air quality, for the purpose of identifying common practices and of assessing the impacts that choices of sample collection media and analytical methods and instrumentation can have on TVOC results. The paper also presents the results of laboratory and field comparisons of three TVOC methods. These are a flame-ionization-detector (FID) method, a gas chromatography/mass spectrometry (GC/MS) method, and a method employing a photoacoustic infrared (IR) gas monitor. The laboratory experiments were conducted with eight different mixtures of VOCs. The FID method demonstrated an average accuracy of 93 ± 18 percent when the measured values were calculated as concentrations of carbon. The FID and GC/MS methods demonstrated average accuracies of 77±37 and 75±22 percent, respectively, when the measured hydrocarbon-equivalent values were compared to the expected mass concentrations of the mixtures. The higher uncertainty for the FID was largely due to the low mass response of 27 percent for chlorinated compounds. The response of the IR gas monitor varied between 6 and 560 percent for different classes of compounds. Air samples from ten buildings were analyzed by both the FID and GC/MS methods. The results were highly correlated and similar, with the GC/MS values approximately 20 percent higher on average.     

Indoor gaseous air pollutants determinants in office buildings—The OFFICAIR project

The aim of this study was to identify determinants of aldehyde and volatile organic compound (VOC) indoor air concentrations in a sample of more than 140 office rooms, in the framework of the European OFFICAIR research project. A large field campaign was performed, which included (a) the air sampling of aldehydes and VOCs in 37 newly built or recently retrofitted office buildings across 8 European countries in summer and winter and (b) the collection of information on building and offices’ characteristics using checklists. Linear mixed models for repeated measurements were applied to identify the main factors affecting the measured concentrations of selected indoor air pollutants (IAPs). Several associations between aldehydes and VOCs concentrations and buildings’ structural characteristic or occupants’ activity patterns were identified. The aldehyde and VOC determinants in office buildings include building and furnishing materials, indoor climate characteristics (room temperature and relative humidity), the use of consumer products (eg, cleaning and personal care products, office equipment), as well as the presence of outdoor sources in the proximity of the buildings (ie, vehicular traffic). Results also showed that determinants of indoor air concentrations varied considerably among different type of pollutants.     

Unexpected increase in indoor pollutants after the introduction of a smoke‐free policy in a correctional center

Correctional centers (prisons) are one of the few non‐residential indoor environments where smoking is still permitted. However, few studies have investigated indoor air quality (IAQ) in these locations. We quantified the level of inmate and staff exposure to secondhand smoke, including particle number (PN) count, and we assessed the impact of the smoking ban on IAQ. We performed measurements of indoor and outdoor PM_2.5 and PN concentrations, personal PN exposure levels, volatile organic compounds (VOCs), and nicotine both before and after a complete indoor smoking ban in an Australian maximum security prison. Results show that the indoor 24‐h average PM_2.5 concentrations ranged from 6 (±1) μg/m³ to 17 (±3) μg/m³ pre‐ban. The post‐ban levels ranged from 7 (±2) μg/m³ to 71 (±43) μg/m³. While PM_2.5 concentrations decreased in one unit post‐ban, they increased in the other two units. Similar post‐ban increases were also observed in levels of PN and VOCs. We describe an unexpected increase of indoor pollutants following a total indoor smoking ban in a prison that was reflected across multiple pollutants that are markers of smoking. We hypothesise that clandestine post‐ban smoking among inmates may have been the predominant cause.     

Measured performance of filtration and ventilation systems for fine and ultrafine particles and ozone in an unoccupied modern California house

This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250 m downwind of the I‐80 freeway in Sacramento, California. Systems were evaluated for reducing indoor concentrations of outdoor particles in summer and fall/winter, ozone in summer, and particles from stir‐fry cooking. Air exchange rate was measured continuously. Energy use was estimated for year‐round operation in California. Exhaust ventilation without enhanced filtration provided indoor PM_2.5 that was 70% lower than outdoors. Supply ventilation with MERV13 filtration provided slightly less protection, whereas supply MERV16 filtration reduced PM_2.5 by 97‐98% relative to outdoors. Supply filtration systems used little energy but provided no benefits for indoor‐generated particles. Systems with MERV13‐16 filter in the recirculating heating and cooling unit (FAU) operating continuously or 20 min/h reduced PM_2.5 by 93‐98%. Across all systems, removal percentages were higher for ultrafine particles and lower for black carbon, relative to PM_2.5. Indoor ozone was 3‐4% of outdoors for all systems except an electronic air cleaner that produced ozone. Filtration via the FAU or portable filtration units lowered PM_2.5 by 25‐75% when operated over the hour following cooking. The energy for year‐round operation of FAU filtration with an efficient blower motor was estimated at 600 kWh/year.     

Housing characteristics and indoor air quality in households of Alaska Native children with chronic lung conditions

Alaska Native children experience high rates of respiratory infections and conditions. Household crowding, indoor smoke, lack of piped water, and poverty have been associated with respiratory infections. We describe the baseline household characteristics of children with severe or chronic lung disease participating in a 2012–2015 indoor air study. We monitored indoor PM2.5, CO₂, relative humidity %, temperature, and VOCs and interviewed caregivers about children's respiratory symptoms. We evaluated the association between reported children's respiratory symptoms and indoor air quality indicators using multiple logistic regression analysis. Compared with general US households, study households were more likely overcrowded 73% (62%–82%) vs 3.2% (3.1%–3.3%); had higher woodstove use as primary heat source 16% (9%–25%) vs 2.1% (2.0%–2.2%); and higher proportion of children in a household with a smoker 49% (38%–60%) vs 26.2% (25.5%–26.8%). Median PM2.5 was 33 μg/m³. Median CO₂ was 1401 ppm. VOCs were detectable in all homes. VOCs, smoker, primary wood heat, and PM2.5>25 μg/m³ were associated with higher risk for cough between colds; VOCs were associated with higher risk for wheeze between colds and asthma diagnosis. High indoor air pollutant levels were associated with respiratory symptoms in household children, likely related to overcrowding, poor ventilation, woodstove use, and tobacco smoke.     

Microbial volatile organic compounds in the air of moldy and mold-free indoor environments

A single-blinded study was performed to analyze whether indoor environments with and without mold infestation differ significantly in microbial volatile organic compounds (MVOC) concentrations. Air sampling for MVOC was performed in 40 dwellings with evident mold damage and in 44 dwellings, where mold damage was excluded after a thorough investigation. The characteristics of the dwellings, climatic parameters, airborne particles and air exchange rates (AER) were recorded. The parameters mold status, characteristics of the interiors and measured climatic parameters were included in the multiple regression model. The results show no significant association between most of the analyzed MVOC and the mold status. Only the compounds 2-methyl-1-butanol and 1-octen-3-ol indicated a statistically significant, but weak association with the mold status. However, the concentrations of the so-called MVOC were mainly influenced by other indoor factors. 2-Methylfuran and 3-methylfuran, often used as main indicators for mold damage, had a highly significant correlation with the smoking status. These compounds were also significantly correlated with the humidity and the AER. The compounds 3-methyl-1-butanol, 2-hexanone, 3-heptanone and dimethyl disulfide were weakly correlated with the recorded parameters, the humidity being the strongest influencing factor. Only 2-methyl-1-butanol and 1-octen-3-ol showed a statistically significant association with the mold status; however, only a small portion (10% in this case) of the total variability could be explained by the predictor mold status; they do not qualify as indicator compounds, because such minor correlations lead to a too excessive part of incorrect classifications, meaning that the diagnostic sensitivity and specificity of these compounds are too low. PRACTICAL IMPLICATIONS: The assumption that mold infestations might be detected by microbial VOC emissions must be considered with great reservation. The major part of the total variability of the measured MVOC concentrations originates from not known influencing factors and/or from factors not directly associated with the mold status of the dwellings (confounders). More specific and sensitive markers for the assessment of the mold status should be found, if the screening for mold infestations should be performed by volatile organic compounds.     

A Study of Human Reactions to Emissions from Building Materials in Climate Chambers. Part II: VOC Measurements,Mouse Bioassay,and Decipol Evaluation in the 1–2 mg/m3 TVOC Range

Monitoring of human reactions to the emission of formaldehyde and volatile organic compounds (VOC) from four commonly used building materials was carried out. The building materials were: a painted gypsum board, a rubber floor, a nylon carpet, and a particle board with an acid-curing paint. The exposures were performed in climate chambers. The air quality was quantified on the decipol scale by a trained panel, measurements of formaldehyde and VOC being performed simultaneously. The irritating potency of the materials was measured by a mouse bioassay. The VOC measurements showed several malodorants and irritants. Some abundant VOC identified in the head-space analyses were absent in the climate chamber air. The rubber floor and the nylon carpet exhibited a marked increase in decipols compatible with a number of odorous VOC identified in the air. A high formaldehyde concentration (minimum 743μg/m³) was measured for the particle board coated with an acid-curing paint. This was not reflected by a corresponding relatively high decipol value but a long-lasting irritating potency was observed in the mouse bioassay. TVOC sampled on Tenax and expressed in mass per volume as well as in molar concentration, and decipol evaluation both have limitations and should be used with caution as indicators of (perceived) indoor air quality. Eye irritation expressed by means of the eye index reflecting the tear film quality index (comprised of break-up time, foam formation, thickness of the precorneal lipid layer of the tear film, and epithelial damage) was found to be insensitive to formaldehyde and a VOC mixture but sensitive to TVOC concentrations of 1–2 mg/m³. Lipophilic VOC may be the cause of reduced tear film quality by destabilization of the lipid multilayer of the tear film.     

Exposure reductions associated with introduction of solar lamps to kerosene lamp‐using households in Busia County,Kenya

Solar lamps are a clean and potentially cost‐effective alternative to polluting kerosene lamps used by millions of families in developing countries. By how much solar lamps actually reduce exposure to pollutants, however, has not been examined. Twenty households using mainly kerosene for lighting were enrolled through a secondary school in Busia County, Kenya. Personal PM_2.5 and CO concentrations were measured on a school pupil and an adult in each household, before and after provision of 3 solar lamps. PM_2.5 concentrations were measured in main living areas, pupils' bedrooms, and kitchens. Usage sensors measured use of kerosene and solar lighting devices. Ninety percent of baseline kerosene lamp use was displaced at 1‐month follow‐up, corresponding to average PM_2.5 reductions of 61% and 79% in main living areas and pupils' bedrooms, respectively. Average 48‐h exposure to PM_2.5 fell from 210 to 104 μg/m³ (?50%) among adults, and from 132 to 35 μg/m³ (?73%) among pupils. Solar lamps displaced most kerosene lamp use in at least the short term. If sustained, this could mitigate health impacts of household air pollution in some contexts. Achieving safe levels of exposure for all family members would likely require also addressing use of solid‐fuel stoves.     

Relationship between selected indoor volatile organic compounds, so-called microbial VOC, and the prevalence of mucous membrane symptoms in single family homes

Microorganisms are known to produce a range of volatile organic compounds, so-called microbial VOC (MVOC). Chamber studies where humans were exposed to MVOC addressed the acute effects of objective and/or subjective signs of mucosal irritation. However, the effect of MVOC on inhabitants due to household exposure is still unclear. The purpose of this epidemiological study was to measure indoor MVOC levels in single family homes and to evaluate the relationship between exposure to them and sick building syndrome (SBS). All inhabitants of the dwellings were given a self-administered questionnaire with standardized questions to assess their symptoms. Air samples were collected and the concentrations of eight selected compounds in indoor air were analyzed by gas chromatography/mass spectrometry — selective ion monitoring mode (GC/MS-SIM). The most frequently detected MVOC was 1-pentanol at a detection rate of 78.6% and geometric mean of 0.60 μg/m³. Among 620 participants, 120 (19.4%) reported one or more mucous symptoms; irritation of the eyes, nose, airway, or coughing every week (weekly symptoms), and 30 (4.8%) reported that the symptoms were home-related (home-related symptoms). Weekly symptoms were not associated with any of MVOC, whereas significant associations between home-related mucous symptoms and 1-octen-3-ol (per log₁₀-unit: odds ratio (OR) 5.6, 95% confidence interval (CI): 2.1 to 14.8) and 2-pentanol (per log₁₀-unit: OR 2.3, 95% CI: 1.0 to 4.9) were obtained after adjustment for gender, age, and smoking. Associations between home-related symptoms and 1-octen-3-ol remained after mutual adjustment. However, concentrations of the selected compounds in indoors were lower than the estimated safety level in animal studies. Thus, the statistically significant association between 1-octen-3-ol may be due to a direct effect of the compounds or the associations may be being associated with other offending compounds. Additional studies are needed to evaluate these possibilities.     

Household air pollution from wood burning in two reconstructed houses from the Danish Viking Age

During 13 winter weeks, an experimental archeology project was undertaken in two Danish reconstructed Viking Age houses with indoor open fireplaces. Volunteers inhabited the houses under living conditions similar to those of the Viking Age, including cooking and heating by wood fire. Carbon monoxide (CO) and particulate matter (PM_2.5) were measured at varying distances to the fireplace. Near the fireplaces CO (mean) was 16 ppm. PM_2.5 (mean) was 3.40 mg/m³, however, measured in one house only. The CO:PM mass ratio was found to increase from 6.4 to 22 when increasing the distance to the fire. Two persons carried CO sensors. Average personal exposure was 6.9 ppm, and from this, a personal PM_2.5 exposure of 0.41 mg/m³ was estimated. The levels found here were higher than reported from modern studies conducted in dwellings using biomass for cooking and heating. While this may be due to the Viking house design, the volunteer's lack of training in attending a fire maybe also played a role. Even so, when comparing to today's issues arising from the use of open fires, it must be assumed that also during the Viking Age, the exposure to woodsmoke was a contributing factor to health problems.     

固相微萃取法同时分析源水中54种挥发性有机物

建立了同时测定饮用水源水中54种挥发性有机物的前处理方法———顶空固相微萃取法。用65μm聚二甲基硅氧烷二乙烯基苯(PDMS-DVB)固相微萃取柱顶空萃取水样中的挥发性有机物,萃取物用气相色谱/质谱联用法(GC-MS)分析,采用质谱(MS)检测器的选择离子监测模式(SIM)和内标法进行定量分析。试验优化了顶空固相微萃取条件,如萃取柱涂层、盐度、萃取温度和萃取时间等。采用优化后的条件获得的方法检出限为0.01～0.37μg/L,在所测浓度范围内校准曲线的相关系数良好(除三氯甲烷和四氯化碳外均大于0.991),对0.60μg/L标准水样测得结果的RSD均小于15%;实际饮用水源水样加标回收率均值和RSD分别为73.1%～130%和1.4%～19%(n=6)。该方法适用于饮用水源水中挥发性有机物的监测分析。     

Detection of human effluents by a MOS gas sensor in correlation to VOC quantification by GC/MS

Due to increasing interest in indoor air quality (IAQ) monitoring for demand controlled ventilation (DCV) aiming at improved perceived air quality, health, energy and cost saving, the objective of this study has been the development of a sensor module based on a single microelectromechanical-system (MEMS) metal oxide semiconductor (MOS) gas sensor for IAQ monitoring as close as possible to the human sensory impression in indoor environments. Based on the results of a statistical evaluation on human induced volatile organic compounds (VOCs) in the ambient air of indoor environments correlating with human presence and perceived air quality, the performance of differently doped SnO₂ thick film gas sensor materials has been investigated in laboratory and by means of field tests in order to find the most promising sensor material for IAQ monitoring based on the detection of changes of human induced VOCs in indoor air. Implementation of an empirical evaluation algorithm reversing proportionality of anthropogenic CO₂ production and other bio-effluent generation allows prediction of CO₂ equivalent units. Analytical instrumentation and reference sensors served to evaluate the effectiveness of the developed sensor module in real-life.