Levels and sources of volatile organic compounds in homes of children with asthma

Many volatile organic compounds (VOCs) are classified as known or possible carcinogens, irritants, and toxicants, and VOC exposure has been associated with the onset and exacerbation of asthma. This study characterizes VOC levels in 126 homes of children with asthma in Detroit, Michigan, USA. The total target VOC concentration ranged from 14 to 2274 μg/m³ (mean = 150 μg/m³; median = 91 μg/m³); 56 VOCs were quantified; and d‐limonene, toluene, p, m‐xylene, and ethyl acetate had the highest concentrations. Based on the potential for adverse health effects, priority VOCs included naphthalene, benzene, 1,4‐dichlorobenzene, isopropylbenzene, ethylbenzene, styrene, chloroform, 1,2‐dichloroethane, tetrachloroethene, and trichloroethylene. Concentrations varied mostly due to between‐residence and seasonal variation. Identified emission sources included cigarette smoking, solvent‐related emissions, renovations, household products, and pesticides. The effect of nearby traffic on indoor VOC levels was not distinguished. While concentrations in the Detroit homes were lower than levels found in other North American studies, many homes had elevated VOC levels, including compounds that are known health hazards. Thus, the identification and control of VOC sources are important and prudent, especially for vulnerable individuals. Actions and policies to reduce VOC exposures, for example, sales restrictions, improved product labeling, and consumer education, are recommended.     

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.

     

Biological and environmental exposure monitoring of volatile organic compounds among nail technicians in the Greater Boston area

Nail technicians are exposed to volatile organic compounds (VOCs) from nail products, but no studies have previously measured VOC biomarkers for these workers. This study of 10 nail technicians aimed to identify VOCs in nail salons and explore relationships between air concentrations and biomarkers. Personal and area air samples were collected using thermal desorption tubes during a work shift and analyzed using gas chromatography/mass spectrometry (GC/MS) for 71 VOCs. Whole blood samples were collected pre‐shift and post‐shift, and analyzed using GC/MS for 43 VOCs. Ventilation rates were determined using continuous CO₂ measurements. Predominant air VOC levels were ethyl methacrylate (median 240 µg/m³), methyl methacrylate (median 205 µg/m³), toluene (median 100 µg/m³), and ethyl acetate (median 639 µg/m³). Blood levels were significantly higher post‐shift than pre‐shift for toluene (median pre‐shift 0.158 µg/L and post‐shift 0.360 µg/L) and ethyl acetate (median pre‐shift <0.158 µg/L and post‐shift 0.510 µg/L); methacrylates were not measured in blood because of their instability. Based on VOCs measured in these seven nail salons, we estimated that emissions from Greater Boston area nail salons may contribute to ambient VOCs. Ventilation rates did not always meet the ASHRAE guideline for nail salons. There is a need for changes in nail product formulation and better ventilation to reduce VOC occupational exposures.     

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.     

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/m³ and 22 μg/m³ for low‐VOC homes and 45 μg/m³ and 30 μg/m³ for conventional.     

Concentrations of Volatile Organic Compounds in Indoor Air – A Review

A review is presented of investigations of volatile organic compound (VOC) concentrations in indoor air of buildings of different classifications (dwellings, offices, schools, hospitals) and categories (established, new and complaint buildings). Measured concentrations obtained from the published literature and from research in progress overseas were pooled so that VOC concentration profiles could be derived for each building classification/category. Mean concentrations of individual compounds in established buildings were found to be generally below 50 μg/m³, with most below 5 μg/m³. Concentrations in new buildings were much greater, often by an order of magnitude or more, and appeared to arise from construction materials and building contents. The nature of these sources and approaches to reduce indoor air concentrations by limiting source VOC emissions is discussed. Total VOC (TVOC) concentrations were substantially higher than concentrations of any individual VOCs in all situations, reflecting the large number of compounds present, but interpretation of such measurements was limited by the lack of a common definition for TVOC relevant to occupant exposure.     

Factors controlling volatile organic compounds in dwellings in Melbourne,Australia

This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n‐butane, 2‐methylbutane, toluene, formaldehyde, acetaldehyde, d‐limonene, ethanol, 2‐propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum‐like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings.     

Air exchange rates and migration of VOCs in basements and residences

Basements can influence indoor air quality by affecting air exchange rates (AERs) and by the presence of emission sources of volatile organic compounds (VOCs) and other pollutants. We characterized VOC levels, AERs, and interzonal flows between basements and occupied spaces in 74 residences in Detroit, Michigan. Flows were measured using a steady‐state multitracer system, and 7‐day VOC measurements were collected using passive samplers in both living areas and basements. A walk‐through survey/inspection was conducted in each residence. AERs in residences and basements averaged 0.51 and 1.52/h, respectively, and had strong and opposite seasonal trends, for example, AERs were highest in residences during the summer, and highest in basements during the winter. Airflows from basements to occupied spaces also varied seasonally. VOC concentration distributions were right‐skewed, for example, 90th percentile benzene, toluene, naphthalene, and limonene concentrations were 4.0, 19.1, 20.3, and 51.0 μg/m³, respectively; maximum concentrations were 54, 888, 1117, and 134 μg/m³. Identified VOC sources in basements included solvents, household cleaners, air fresheners, smoking, and gasoline‐powered equipment. The number and type of potential VOC sources found in basements are significant and problematic, and may warrant advisories regarding the storage and use of potentially strong VOCs sources in basements.     

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.     

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/m³, respectively. The levels of acetaldehyde and TVOCs exceeded the indoor guideline (48 μg/m³) and interim target (400 μg/m³) 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.     

Indoor air quality in shopping and storage areas

In retail stores, workers are constantly exposed to new manufactured goods. The issue of the exposure of retail workers to volatile organic compounds (VOCs) should clearly be considered. Therefore, this study provides data regarding VOC concentrations in ten French retail stores. The stores were chosen to represent various products: sports goods, shoes and leather, furniture, car equipment, bazaars, online-sales storage, clothes, books, DIY (do-it-yourself), and household appliances. VOCs and aldehydes were actively sampled on the same day in five to seven locations per building and outdoors. Toluene and formaldehyde were omnipresent with indoor concentrations reaching 252 and 53 µg/m³, respectively. The car equipment store, followed by clothing, shoes, and leather, and DIY stores showed the worst indoor air quality. High concentrations were measured, for example, the maximum α-pinene concentration in the furniture and DIY stores was 364 and 141 µg/m³, respectively, and the heptane concentration in the car equipment store reached 1,316 µg/m³. Two VOCs classified as toxic to reproduction were measured: hexane in the car equipment store and the bazaar, and dimethylformamide in the sports goods store. This study shows some disparities in the indoor concentrations among different locations in the same store, particularly between sales and storage areas.     

Volatile organic pollutants in new and established buildings in Melbourne, Australia

Volatile organic compounds (VOCs) within new and established buildings have been determined and factors significant to their presence have been identified. In established dwellings, total volatile organic compound (TVOC) concentrations were low, but were approximately four times higher than in outdoor air, showing a dominant effect of indoor sources. The presence of attached garages, site contamination and 'faulty' wool carpet were associated with higher indoor pollution. In three dwellings, unidentified sources of benzene were indicated. Much higher VOC concentrations were observed in new or renovated buildings, persisting above "baseline" levels for several weeks, concentration decay rate correlating with VOC molecular volume, indicating emissions were limited by material diffusion processes. VOC and formaldehyde emission decays in a new dwelling occurred by a double-exponential source model. This shows that persistent low levels of volatile organic pollutants in established dwellings can occur due to long-term emissions from building materials.     

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.     

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.     

Volatile Organic Compounds in Ventilating Air in Buildings at Different Sampling Points in the Buildings and their Relationship with the Prevalence of Occupant Symptoms

Total volatile organic compounds (TVOC) are determined in intake, room-supply and room air in 86 office rooms in 29 office buildings in northern Sweden. Measurements of formaldehyde were also made in room air. Building and room characteristics were identified and symptom reports collected from 1087 office workers. Concentrations of TVOC and formaldehyde in room air were low, with mean values of 71 µg/m³ and 31 µg/m³, respectively. The TVOC concentration was generally lower in room air than in supply air or intake air. The “loss” (difference in measured values) of TVOC from supply to room air was associated with raised concentrations of formaldehyde and raised prevalences of occupant symptoms. High TVOC concentrations in room air were associated with reduced prevalences of occupant symptoms.     

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.     

On-site passive flux sampler measurement of emission rates of carbonyls and VOCs from multiple indoor sources

In indoor environments with high levels of air pollution, it is desirable to remove major sources of emissions to improve air quality. In order to identify the emission sources that contribute most to the concentrations of indoor air pollutants, we used passive flux samplers (PFSs) to measure emission rates of carbonyl compounds and volatile organic compounds (VOCs) from many of the building materials and furnishings present in a room in a reinforced concrete building in Tokyo, Japan. The emission flux of formaldehyde from a desk was high (125 μg/m²/h), whereas fluxes from a door and flooring were low (21.5 and 16.5 μg/m²/h, respectively). The emission fluxes of toluene from the ceiling and the carpet were high (80.0 and 72.3 μg/m²/h, respectively), whereas that from the flooring was low (9.09 μg/m²/h). The indoor and outdoor concentrations of formaldehyde were 61.5 and 8.64 μg/m³, respectively, and those of toluene were 43.2 and 17.5 μg/m³, respectively. The air exchange rate of the room as measured by the perfluorocarbon tracer (PFT) method was 1.84/h. Taking into consideration the area of the emission sources, the carpet, ceiling, and walls were identified as the principal emission sources, contributing 24%, 20%, and 22% of the formaldehyde, respectively, and 22%, 27%, and 14% of the toluene, respectively, assuming that the emission rate from every major emission sources could be measured. In contrast, the door, the flooring, and the desk contributed little to the indoor levels of formaldehyde (1.0%, 0.54%, and 4.1%, respectively) and toluene (2.2%, 0.31%, and 0.85%, respectively).     

UV-PCO device for indoor VOCs removal: Investigation on multiple compounds effect

Current design models for ultraviolet photocatalytic oxidation (UV-PCO) devices often assume that the air contains only one volatile organic compound (VOC) species or all the VOCs in the air can be treated on a non-interacting basis. However, trace-level multiple VOCs co-exist in most indoor environments. This paper assesses the significance of interference effects among different VOCs for indoor applications by full-scale “pull-down” experiments assisted with model simulations. Multiple versus single VOC tests were performed on selected groups of compounds under low concentration levels. Removal efficiency for each compound was calculated. It was found that the interference effect among test VOCs were generally small in the 2-VOC and 3-VOC mixture tests performed on toluene, ethylbenzene, octane, decane and dodecane with initial concentration of approximate 1 mg/m³ for each compound. However, in the 16 VOC mixture test, the interference effect among different VOCs became quite obvious, and compounds with lower removal efficiency in the single compound test appeared to also have relatively lower efficiency and more obvious delay period in the initial reaction. The L–H model appears to be able to account for this effect if reaction rate constants can be accurately estimated. Results, although limited, indicate that interference between multiple VOCs may not be neglected for the PCO reactor for indoor applications where the number of VOCs species is large and the TVOC concentration is high.     

Investigation of volatile organic compounds in office buildings in Bangkok,Thailand: Concentrations,sources, and occupant symptoms

To conserve energy, office buildings with air-conditioning systems in Thailand are operated with a tight thermal envelope. This leads to low fresh-air ventilation rates and is thought to be partly responsible for the sick building syndrome symptoms reported by occupants. The objectives of this study are to measure concentrations and to determine sources of 13 volatile organic compounds (VOCs) in office buildings with air-conditioning systems in the business area of Bangkok. Indoor and outdoor air samples from 17 buildings were collected on Tenax-TA^™ sorbent tubes and analyzed for individual VOCs by thermal desorption-gas chromatography/mass spectrometry (TD–GC/MS). Building ventilation was measured with a constant injection technique using hexafluorobenzene as a tracer gas. The results show that the VOC concentrations varied significantly among the studied buildings. The two most dominant VOCs were toluene and limonene with average concentrations of 110 and 60.5 μg m⁻³, respectively. A Wilcoxon sum rank test indicated that the indoor concentrations of aromatic compounds and limonene were statistically higher than outdoor concentrations at the 0.05 level, while the indoor concentrations of chlorinated compounds were not. Indoor emission factors of toluene and limonene were found to be highest with the average values of 80.9 and 18.9 μg m⁻² h⁻¹, respectively. Principal component analysis was applied to the emission factors of 13 VOCs, producing three components based on source similarities. Furthermore, a questionnaire survey investigation and field measurements of building air exchange pointed to indoor air complaints related to inadequate ventilation.     

Evaluation on potential for assessing indoor formaldehyde using biosensor system based on swimming behavior of Japanese medaka (oryzias latipes)

In order to develop an early-warning biosensor system for predicting the impact on health of long-term and low-level exposure to indoor chemical compounds, e.g. volatile organic compounds (VOCs), we evaluated the potential for assessing indoor air quality using the biosensor system based on the swimming behavior of Japanese medaka (oryzias latipes) as an indicator of indoor air quality in the beginning. As a technology to dissolve chemical compounds into water efficiently, a micro bubble generator was introduced. The test chemical was formaldehyde which is a representative of chemical compounds existing indoors. The result of the measuring solubility of formaldehyde was that formaldehyde concentration in water was raised to 0.12 mg/L when 1.0 mg/m³ of formaldehyde in air was bubbled for approximately 44 h. The correlation between the 0.1 mg/L of formaldehyde in water, which is roughly equivalent to 0.83 mg/m³ of formaldehyde in air, and the swimming activities of medaka was investigated. The fish showed abnormal behavior compared to one under a control treatment, e.g. the body movement distance decreased and the duration time near the upper water column increased significantly. It was verified that it is possible to detect concentrations of formaldehyde of 0.83 mg/m³ in indoor air using this proposed biosensor system.