Yoko Eitaki

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 microg/m(3). 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 log(10)-unit: odds ratio (OR) 5.6, 95% confidence interval (CI): 2.1 to 14.8) and 2-pentanol (per log(10)-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.

Inhalation Carcinogenicity and Chronic Toxicity of Indium-tin Oxide in Rats and Mice

Inhalation Carcinogenicity and Chronic Toxicity of Indium‐tin Oxide in Rats and Mice: Kasuke Nagano, et al. Japan Bioassay Research Center, Japan Industrial Safety and Health Association—

The relationship between exposure to microbial volatile organic compound and allergy prevalence in single-family homes.

Microbial volatile organic compounds (MVOCs) are a type of VOCs produced by microorganisms. Exposure to 1-octen-3-ol, one of the known MVOCs, has been reported to reduce nasal patency and increase nasal lavage myeloperoxidase, eosinophil cationic proteins, and lysozymes in both experimental and field studies. We reported in a previous paper that 1-octen-3-ol exposure at home is associated with mucosal symptoms. In this study, our aim was to investigate the relationship between asthma and allergies and MVOC exposure in single-family homes. The subjects were 624 inhabitants of 182 detached houses in six regions of Japan. Air samples were collected using diffusive samplers, and the concentrations of eight selected MVOCs were analyzed using gas chromatography/mass spectrometry in selected-ion-monitoring mode. Each inhabitant of each of the dwellings was given a self-administered questionnaire. Among the 609 subjects who answered all of the questions about allergies, history of the medical treatment for asthma, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis within the preceding two years was 4.8%, 9.9%, 18.2%, and 7.1%, respectively. A significant association between 1-octen-3-ol (per log(10) unit) and allergic rhinitis odds ratio (OR): 4.10, 95% confidence interval (CI): 1.71 to 9.80 and conjunctivitis (OR: 3.54, CI: 1.17 to 10.7) was found after adjusting for age, sex, tobacco, wall-to-wall carpeting, signs of dampness, history of treatment for hay fever, and other potentially relevant environmental factors. No relationships were found between any MVOCs and asthma or atopic dermatitis after the adjustment. The levels of MVOCs and airborne fungi were only weakly correlated. These results are consistent with previous studies that have associated higher levels of 1-octen-3-ol exposure with increased irritation of nasal and ocular mucosae. Although the indoor-air concentrations of 1-octen-3-ol found in this study were relatively low, we conclude that exposure to MVOC may be related to rhinitis and conjunctivitis.

Urinary Excretion of an Oxidative Stress Marker, 8-hydroxyguanine (8-OH-Gua), among Nickel-cadmium Battery Workers

Urinary Excretion of an Oxidative Stress Marker, 8‐hydroxyguanine (8‐OH‐Gua), among Nickel‐cadmium Battery Workers: Noriyuki Yoshioka, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—The relationship between oxidative stress and carcinogenic metals including nickel and cadmium is a matter of interest. To assess the oxidative stress status of workers exposed to nickel and cadmium simultaneously, we determined urinary excretion of 8‐hydroxyguanine (8‐OH‐Gua), a urinary oxidative stress marker. Our subjects were 66 (64 males and 2 females) nickel‐cadmium battery workers. Spot urine and blood samples were collected. The levels of cadmium in blood (Cd‐B) and nickel in urine (Ni‐U) were determined by graphite furnace atomic absorption spectrophotometry. 8‐OH‐Gua in urine was analyzed using a high performance liquid chromatography‐electrochemical detector (HPLC‐ECD) system. Data on age, sex, duration of present work and smoking status were also obtained from each subject. Creatinine‐adjusted 8‐OH‐Gua was significantly correlated with age, Ni‐U and Cd‐B in univariate analysis, while multivariate analysis revealed that Ni‐U and Cd‐B were significant independent variables and that these two biological exposure indices were positively correlated with 8‐OH‐Gua. The data were also analyzed in the context of mixture toxicity. The subjects were divided into groups based on median level of Ni‐U and Cd‐B (2.86 μg/g creatinine and 0.23 μg/dl, respectively). Workers with high Ni‐U/high Cd‐B (Group IV) had the highest levels of 8‐OH‐Gua levels (GM (GSD), 21.7(2.0)), followed by those with high Ni‐U/low Cd‐B (11.5(1.6) Group III), those with low Ni‐U/high Cd‐B (8.9(1.9) Group II), and those with low Ni‐U/low Cd‐B (8.5(1.5) Group I). The p values of Students t‐tests between Group I and Group II, III and IV were 0.847, 0.050 and <0.001, respectively. The combined effect of Cd and Ni on the urinary excretion of 8‐OH‐Gua departed from additivity.

Two- and 13-week inhalation toxicities of indium-tin oxide and indium oxide in rats.

Two‐ and 13‐week Inhalation Toxicities of Indium‐tin Oxide and Indium Oxide in Rats: Kasuke Nagano, et al. Japan Bioassay Research Center, Japan Industrial Safety and Health Association—

Pulmonary Toxicity in Mice by 2- and 13-week Inhalation Exposures to Indium-tin Oxide and Indium Oxide Aerosols

Pulmonary Toxicity in Mice by 2‐ and 13week Inhalation Exposures to Indium‐tin Oxide and Indium Oxide Aerosols: Kasuke Nagano, et al., Japan Bioassay Research Center, Japan Industrial Safety and Health Association—

Diffusive sampling and measurement of microbial volatile organic compounds in indoor air.

Microbial volatile organic compounds (MVOC), chemicals emitted from various microorganisms, in indoor air have been of concern in recent years. For large field studies, diffusive samplers are widely used to measure indoor environments. Since the sampling rate of a sampler is a fundamental parameter to calculate concentration, the sampling rates of eight MVOC with diffusive samplers were determined experimentally using a newly developed water-bubbling method: air was supplied to the MVOC-solutions and the vapor collected in an exposure bag, where diffusive and active samplers were placed in parallel for comparison. Correlations between the diffusive and active samplings gave good linear regressions. The sampling rates were 30-35 ml/min and the detection limits were 0.044-0.178 microg/m(3), as determined by GC/MS analysis. Application of the sampling rates in indoor air was validated by parallel sampling of the diffusive and active sampling method. 5% Propan-2-ol/CS(2) was the best solvent to desorb the compounds from absorbents. The procedure was applied to a field study in 41 dwellings. The most frequently detected compounds were hexan-2-one and heptan-2-one, with 97.5% detection rates and geometric mean values of 0.470 and 0.302 microg/m(3), respectively. This study shows that diffusive samplers are applicable to measure indoor MVOC levels. Practical Implications At present, there are still limited reports on indoor Microbial Volatile Organic Compounds (MVOC) levels in general dwellings and occupants health. Compared with active sampling methods, air sampling using a diffusive sampler is particularly advantageous for use in large field studies due to its smallness, light-size, easy-handling, and cost-effectiveness. In this study, sampling rates of selected MVOC of the diffusive sampler were determined using the water-bubbling method: generating gases by water-bubbling and exposing the diffusive and active samplers at the same time. The obtained sampling rates were validated, and the method was applied to the field study.

Assessment of workplace air concentrations of indium dust in an indium-recycling plant

Assessment of Workplace Air Concentrations of Indium Dust in an Indium‐recycling Plant: Hiroyuki MIYAUCHI, et al. The Association of Industrial Health—

Exposure Assessment of ETBE in Gas Station Workers and Gasoline Tanker Truck Drivers

Exposure Assessment of ETBE in Gas Station Workers and Gasoline Tanker Truck Drivers: Yoko Eitaki, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—

Stability in Urine of Authentic Phenylglyoxylic and Mandelic Acids as Urinary Markers of Occupational Exposure to Styrene

Stability in Urine of Authentic Phenylglyoxylic and Mandelic Acids as Urinary Markers of Occupational Exposure to Styrene: Yoko Eitaki, et al. Osaka Occupational Health Service Center, Japan Industrial Safety and Health Association—Phenylglyoxylic acid (PhGA) and mandelic acid (MA) are two popular urinary markers of occupational exposure to styrene, but PhGA has been considered to be relatively unstable when urine samples are stored. This study was initiated to examine the stability of PhGA in urine under two storage conditions, i.e., at room temperature (at 25°C) and in refrigeration (at 4°C) for up to 14 days. The experiments showed that no substantial decrease was observed in either PhGA or MA even at room temperature within one day, but, depending on urine samples, a gradual decrease in PhGA took place both at 4°C and more markedly at 25°C when kept for a week. Further reduction was observed in two weeks even at 4°C. No reduction was observed in MA up to two weeks both at 4°C and at 25°C. The observation on stability of MA and limited stability of PhGA (i.e., no significant decrease for 4 days when stored as refrigerated) was confirmed by a repeated experiment. Further analyses disclosed that PhGA when stored at 4°C tended to be more unstable when urine samples were alkaline (e.g., at pH 8) rather than acidic (e.g., at pH 6 or below), but the trend varied subject to individual samples. Thus, the practical recommendation is that urine samples should be analyzed on the day of collection if all possible, or kept at 4°C, or more preferably at –20°C. Refrigeration will allow storage of up to 4 days without substantial decrease in either PhGA or MA.