Abstract Background In Japan, there are currently no definitive conclusions regarding the characteristics of multiple chemical sensitivity (MCS) and electromagnetic hypersensitivity (EHS). This study aimed to determine the prevalence and correlation of MCS and EHS with age, sex, and depression in the Japanese population. Methods An anonymous self-report questionnaire was distributed to 2,007 participants. Variables such as MCS, EHS, depression score, and demographic characteristics were individually evaluated using the U-test, chi-squared test, and correlation analyses. Moreover, we performed a covariance structure analysis to build a structural equation model. Results Older individuals and women were more likely to exhibit MCS and EHS symptoms. Moreover, depression was correlated with MCS and EHS. Conclusions Although MCS and EHS are strongly correlated, they exhibit distinct characteristics and symptoms, indicating that they can be regarded as separate conditions.

環境ストレスには物理的感覚ストレス，化学的感覚ストレス，免疫・凝固系ストレス，心理社会的ストレス，内部環境ストレスがある．環境ストレスに対して生体が過敏症（ストレス感覚入力系の過敏状態）や不耐症（ストレス反応出力系の不全状態）を呈する病態を環境ストレス過敏症（不耐症）と定義した．その病像は視床下部性ストレス不耐・疲労症候群（脳室周囲器官制御破綻症候群）であり，自律神経・内分泌・免疫症状，筋痛，疲労，記憶障害等の多彩な症状が重層的に起こる．基礎疾患が明らかでない特発性タイプと，筋痛性脳脊髄炎・慢性疲労症候群，脳脊髄液漏出症，HPVワクチン後遺症，COVID-19後遺症，シックハウス症候群，ネオニコチノイド暴露など，基礎疾患が明らかな症候性タイプがある．3ステージ仮説（遺伝的要因，発症要因，トリガー要因）に基づき，その病態や予防について論じた．分子病態仮説としてプリン作動性神経伝達障害を考えた．

We assessed the risk of COVID-19 infection in a healthcare worker (HCW) from multiple pathways of exposure to SARS-CoV-2 in a health-care setting of short distance of 0.6 m between the HCW and a patient while caring, and evaluated the effectiveness of a face mask and a face shield using a model that combined previous infection-risk models. The multiple pathways of exposure included hand contact via contaminated surfaces and an HCW's fingers with droplets, droplet spray, and inhalation of inspirable and respirable particles. We assumed a scenario of medium contact time (MCT) and long contact time (LCT) over 1 day of care by an HCW. SARS-CoV-2 in the particles emitted by coughing, breathing, and vocalization (only in the LCT scenario) by the patient were considered. The contribution of the risk of infection of an HCW by SARS-CoV-2 from each pathway to the sum of the risks from all pathways depended on virus concentration in the saliva of the patient. At a virus concentration in the saliva of 101-105 PFU mL-1 concentration in the MCT scenario and 101-104 PFU mL-1 concentration in the LCT scenario, droplet spraying was the major pathway (60%-86%) of infection, followed by hand contact via contaminated surfaces (9%-32%). At a high virus concentration in the saliva (106-108 PFU mL-1 in the MCT scenario and 105-108 PFU mL-1 in the LCT scenario), hand contact via contaminated surfaces was the main contributor (41%-83%) to infection. The contribution of inhalation of inspirable particles was 4%-10% in all assumed cases. The contribution of inhalation of respirable particles increased as the virus concentration in the saliva increased, and reached 5%-27% at the high saliva concentration (107 and 108 PFU mL-1) in the assumed scenarios using higher dose-response function parameter (0.246) and comparable to other pathways, although these were worst and rare cases. Regarding the effectiveness of nonpharmaceutical interventions, the relative risk (RR) of an overall risk for an HCW with an intervention vs. an HCW without intervention was 0.36-0.37, 0.02-0.03, and <4.0 × 10-4 for a face mask, a face shield, and a face mask plus shield, respectively, in the likely median virus concentration in the saliva (102-104 PFU mL-1), suggesting that personal protective equipment decreased the infection risk by 63%->99.9%. In addition, the RR for a face mask worn by the patient, and a face mask worn by the patient plus increase of air change rate from 2 h-1 to 6 h-1 was <1.0 × 10-4 and <5.0 × 10-5, respectively in the same virus concentration in the saliva. Therefore, by modeling multiple pathways of exposure, the contribution of the infection risk from each pathway and the effectiveness of nonpharmaceutical interventions for COVID-19 were indicated quantitatively, and the importance of the use of a face mask and shield was confirmed.

Polyvinyl chloride (PVC) sheet containing a plasticizer may emit chemicals, including 2-ethyl-1-hexanol (2EH). There are various ozone sources in indoor and outdoor air. Thus, a time course change of these reaction products of PVC sheet and ozone was monitored using a volatile organic compound (VOC) component monitor in a 20-L chamber with ventilation (air exchange rate was 1.5 air changes per hour). After ozone exposure to the PVC sheet, the peak area of 2EH decreased and the peaks where the area increased were observed in a chromatograph for 3 h, suggesting the generation of oxidation products. The reaction rate constant of 2EH and ozone was 6.5 × 10-7 /ppb/s, and the ozone degradation velocity was 0.033 cm/s. Results suggested a gas-phase reaction of 2EH and ozone, accounting for total ozone decomposition of 2%. Because 2EH and secondary reaction products which were mainly straight-chain aldehyde coexisted with PVC sheet and ozone, PVC sheet may be a source of secondary reaction products, in addition to 2EH, after a certain reaction time.

High ozone concentrations often exist under the reduced pressure conditions observed in aircraft cabins during flight. In this study, we measured the concentrations of the products obtained from the reaction of ozone with limonene in a simulated aircraft cabin environment (i.e., vacuum chamber at approximately 70 kPa). The concentration of total volatile organic compounds increased under reduced pressure when compared to that under atmospheric pressure, whereas the ozone concentration decreased during the hour after limonene was injected into the chamber. These changes can be partially explained by the increased evaporation of limonene under reduced pressure. With respect to secondary products, a decrease in particulate matter was observed under reduced pressure for an initial ozone concentration of 0.4-0.5 mg/m(3). In contrast, the effects of reduced pressure on the concentrations of gaseous products, such as formaldehyde and limonene oxide, were small when the initial ozone concentration was approximately 0.3 mg/m(3). These results indicate that the reaction between limonene and ozone under reduced pressure is similar to that occurring under atmospheric pressure.

Emission rates of diethylhexyl phthalate (DEHP) from building materials, such as vinyl floorings and wall paper, determined using a passive flux sampler (PFS) were constant over the week-long measurement period. Emission rates for vinyl floorings and wallpaper were linearly correlated to the inverse of diffusion distance, which corresponds to the internal depth of the PFS. Surface-air DEHP concentrations (y0) were estimated as 1.3-2.3 μg/m3 for materials having a boundary layer molecular diffusion rate-limiting step. The partition coefficient (Kmaterial-air) was estimated as 3.3-7.5 × 1010 for these materials. Additionally, emission rates of DEHP from same building materials determined using a micro-chamber were 4.5-6.1 μg/m2/h. Mass transfer coefficients in the micro-chamber (hm) were estimated by comparing the results using the PFS and micro-chamber, and these were 1.1-1.2 × 10-3 and 8.1 × 10-4 m/s for vinyl floorings (smooth surface) and wallpaper (rough surface), respectively. The thickness of boundary layer on the surface of building materials in the micro-chamber were estimated to be 2.5-2.6 and 3.7 mm for vinyl floorings and wallpaper, respectively.

BACKGROUND & OBJECTIVES: The Quick Environmental Exposure and Sensitivity Inventory (QEESI) developed by Miller and Prihoda in the USA is used as a questionnaire for patients with multiple chemical sensitivity (MCS) in >10 countries. We developed a Japanese version of QEESI, assessed its reliability and validity, and defined original cut-off values for screening Japanese patients with MCS in 2003. Our recent study revealed that opportunities for exposure to various chemicals had increased for people in Japan, while subjective symptoms of MCS in patients had increased in severity. In this study, we considered new cut-off values that combined QEESI subscale scores based on the current situation in Japan. METHODS: The questionnaire used was a Japanese version of QEESI. The survey was conducted from 2012 to 2015. Participants were 111 patients with MCS (mean age: 46 ± 20, 81% female) initially diagnosed by physicians, and 444 age- and gender-matched controls not diagnosed with MCS by doctors. The discriminatory validity of QEESI scores of patients and controls were evaluated by logistic regression and receiver operating characteristic analyses when considering interactions of the Masking Index (ongoing chemical exposure). New combined cut-off values were then set. RESULTS: New combined cut-off values (meeting conditions of Chemical Intolerances ≥ 30, Symptom Severity ≥ 13, and Life Impacts ≥ 17) showed high sensitivity (82.0%) and specificity (94.4%). Using new criteria when considering ongoing chemical exposure, study participants were categorized as: Very suggestive, Somewhat suggestive, Problematic, and Not suggestive. Participants classified as Very suggestive included 25 (5.6%) controls. CONCLUSIONS: We have set new criteria with combined cut-off values based on current Japanese conditions. Such new criteria can be used for screening and as a diagnostic aid for Japanese patients with MCS and suggest approximately 6% of the Japanese general population may be classified as "Very suggestive people with MCS".

© 2018 Elsevier GmbH Background: Recently, with rapid changes in the Japanese lifestyle, the clinical condition of patients with multiple chemical sensitivity (MCS) may also have undergone change. Thus, we conducted a new survey for subjective symptoms, ongoing chemical exposures, the prevalence of allergic diseases, and presumed onset/trigger factors in patients with MCS and compared results with those of an old survey from ten years ago. Methods: The new survey was conducted from 2012 to 2015 and the old survey was independently conducted from 1999 to 2003, meaning it was not a follow-up study. Patients were initially diagnosed by physicians at five medical institutions with MCS specialty outpatient services, with 111 and 103 patients participating in the new and old surveys, respectively. The controls were a general population living in Japan, with 1313 and 2382 participants in the new and old surveys, respectively. Subjective symptoms and ongoing chemical exposure were evaluated using a quick environmental exposure sensitivity inventory. Additionally, from clinical findings recorded by an attending physician, the prevalence of allergic diseases and presumed onset/trigger factors were evaluated. Differences between new and old surveys were analyzed using logistic regression analyses and significance tests. Results: Compared with ten years ago: (1) Regarding factors affecting patients with ongoing chemical exposures, the proportion of patients affected decreased significantly for two items only (insecticides and second-hand smoke). The proportion of controls showing ongoing exposure to 8 out of 10 items changed significantly. (2) In patients, scores for chemical intolerances, other intolerances, and life impacts increased significantly. (3) In terms of the prevalence of allergic diseases among patients with MCS, bronchial asthma (adjusted odds ratio [AOR]: 5.19), atopic dermatitis (AOR: 3.77), allergic rhinitis (AOR: 5.34), and food allergies (AOR: 2.63) increased significantly, while hay fever (AOR: 0.38) and drug allergies (AOR: 0.40) decreased significantly. (4) With regard to construction and renovation, which was the presumed predominant onset/trigger factor for MCS 10 years ago, this decreased from 68.9% to 35.1%; in contrast, electromagnetic fields (0.0%–26.1%), perfume (0.0%–20.7%), and medical treatment (1.9%–7.2%) increased significantly, confirming the diversification of onset/trigger factors. Conclusion: Compared to ten years ago, for patients with MCS, an increase in avoidance behavior toward chemical substance exposures, which were presumed to be aggravating factors for symptoms, was confirmed. It has been suggested that the ongoing chemical exposure of the general population in Japan has largely changed. In addition, for patients with MCS, chemical intolerances and life impacts have become severe, the prevalence of the main allergic diseases has increased, and onset/trigger factors have become diversified.

In an aircraft cabin during flight, high ozone concentrations often exist in reduced pressure conditions. We measured the concentration of products from the reaction of ozone with limonene in a vacuum chamber, which was used to simulate an aircraft cabin, at approximately 70 kPa. Results indicated that under reduced pressure, the concentration of total volatile organic compounds increased and ozone concentration decreased in comparison with these concentrations at atmospheric pressure. Evidence suggested that these differences were observed because of the increased evaporation of volatile organic compounds under reduced pressure. Regarding secondary products, a decrease in particulate matter was observed under reduced pressure at approximately 0.5 mg/m3 ozone concentration. In contrast, the influence of total pressure on the concentration of gaseous products like formaldehyde, 6-methyl-5-hepten-2-one, and limonene oxide was small at approximately 0.3 mg/m3 ozone concentration. The reaction between limonene and ozone under reduced pressure is thus suggested to be similar to that under atmospheric pressure.

High concentrations of acetaldehyde are often observed in indoor environments. One possible source of this is acetaldehyde formation produced by ethanol from wood building materials. To characterize indoor acetaldehyde formation and propose methods for its reduction, chamber-based experiments were conducted in which alcohols were added to pulverized solid woods. The results indicated that acetaldehyde was generated from the ethanol-added wood materials, and softwoods, namely Japanese cedar, Japanese cypress, and Swedish redwood generated more acetaldehyde than the other three woods. The experiments using different types of alcohols of methanol, ethanol, 1-propanol, and 2-propanol revealed a tendency similar to the reported enzymatic profile of the higher plant-derived alcohol dehydrogenase. It was confirmed that acetaldehyde generation was reduced by treatment methods typically used for inactivating enzymes, namely chemical treatments using pyrazole, borate, and urea and thermal treatments. The findings suggest that the chemical and thermal treatment methods are useful to reduce acetaldehyde generation in indoor environments.

In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health2010, 7, 4127-4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

Microbial volatile organic compounds (MVOCs) produced by the brown-rot fungus Fomitopsis palustris and white-rot fungus Trametes versicolor grown on wood chip and potato dextrose agar were analyzed by GC-MS. In total, 110 organic compounds were identified as MVOCs. Among them, only 23 were MVOCs commonly observed in both types of fungi, indicating that the fungi have differential MVOC expression profiles. In addition, F. palustris and T. versicolor produced 38 and 22 MVOCs, respectively, which were detected only after cultivation on wood chip. This suggests that the fungi specifically released these MVOCs when degrading the cell-wall structure of the wood. Time course analysis of MVOC emission showed that both types of fungi produced the majority of MVOCs during the active phase of wood degradation. As both fungi produced specific MVOCs in the course of wood degradation indicates the possibility of the application of MVOCs as detection markers for wood-decay fungus existing in woody materials.

事務所ビルでは，建築物衛生法により室内CO2濃度1000 ppmを基準として室内空気質の管理がなされている。しかし近年，厚生労働省が定めた室内濃度指針値物質以外の未規制のVOCによる室内空気汚染が問題となり，TVOCによる管理が重要視されている。一方，事務所ビルにおける省エネルギーは喫緊の課題であり，外気導入量の制御による冷暖房の負荷の低減が有効な対策とされている。本研究では，CO2とTVOC濃度を指標とした空調制御による省エネルギーの可能性を検証するため，執務者が不在の既存のオフィス空間においてCO2を定常発生させ，空調制御に伴うCO2とTVOC濃度変化を検証する模擬実験と，実際に稼働している既築ビルの執務中におけるCO2とTVOC濃度の長期測定を行った。その結果，模擬実験では，外気導入量を低減すると室内CO2濃度が理論通り上昇するのに対し，給気風量を低減するとCO2濃度に分布が生じることがわかった。また，執務中の長期測定では，CO2濃度とTVOC濃度の変化は異なる傾向を示したため，これら2つの指標によって室内空気質を管理することの必要性が明らかとなった。そこで，管理基準をCO21000 ppm，TVOC400 μg/m3として空調を制御した場合の外気導入量を推算したところ，現行の設定値に対し43%削減可能と求められた。今回の結果を考慮すれば，VOC発生の少ない既築ビルでは，CO2とTVOCの濃度をモニタリングすることで外気導入量の抑制が可能な場合があり，省エネルギーに寄与できると考えられる。

木材腐朽菌が放散する揮発性有機化合物（MVOC）は壁紙などを通過して壁内から室内へと拡散するため，これをトレーサーとした腐朽診断が開発されれば，床下や壁の内部など住宅の隠れた部位で進行する木材腐朽を非破壊で検知できる優れた腐朽診断技術となることが期待される。そこでMVOCをトレーサーとした腐朽診断技術を開発するための第一段階として，褐色腐朽菌オオウズラタケをモデルとして，本菌が放散するMVOCを３種類の分析装置（加熱脱着GC/MS，プロトン移動反応（PTR）-MSおよびヘッドスペース固相マイクロ抽出（HS-SPME）-GC/MS）によって分析し，木材腐朽菌が放散するMVOCを分析するために適した手法を検討することを試みた。オオウズラタケをPDAで培養し，加熱脱着GC/MSによって分析したところ，26種ものMVOCが特定された。これらのうちの７種の主要化合物（methyl isobutyrate，2,5-dimethylfuran，1-octene，methyl tiglate，methyl 2-furoate，3-octanone，および methyl benzoate）をPTR-MS法により分析した結果，それぞれのMVOCは，その種類によって放散パターンが異なることが明らかとなった。また，HS-SPME-GC/MS分析によって，少量の空気サンプルからのMVOC検出を試みたところ，加熱脱着GC/MSと比較すると検出可能な成分は限られるものの，比較的簡便に７種のMVOCを検出することができた。本研究により得られた情報は，実際に木材中で生育する木材腐朽菌が生産するMVOCを測定する際の技術的基盤となるものである。

Continuous ambient air monitoring systems have been introduced worldwide. However, such monitoring forces autonomous communities to bear a significant financial burden. Thus, it is important to identify pollutant-monitoring stations that are less efficient, while minimizing loss of data quality and mitigating effects on the determination of spatiotemporal trends of pollutants. This study describes a procedure for optimizing a constant ambient air monitoring system in the Kanto region of Japan. Constant ambient air monitoring stations in the area were topologically classified into four groups by cluster analysis and principle component analysis. Then, air pollution characteristics in each area were reviewed using concentration contour maps and average pollution concentrations. We then introduced three simple criteria to reduce the number of monitoring stations: (1) retain the monitoring station if there were similarities between its data and average data of the group to which it belongs; (2) retain the station if its data showed higher concentrations; and (3) retain the station if the monitored concentration levels had an increasing trend. With this procedure, the total number of air monitoring stations in suburban and urban areas was reduced by 36.5%. The introduction of three new types of monitoring stations is proposed, namely, mobile, for local non-methane hydrocarbon pollution, and O-x-prioritized.

This study demonstrates an application of cluster analysis to constant ambient air monitoring data of four pollutants in the Kanto region: NOx, photochemical oxidant (O-x), suspended particulate matter, and non-methane hydrocarbons. Constant ambient air monitoring can provide important information about the surrounding atmospheric pollution. However, at the same time, ambient air monitoring can place a significant financial burden on some autonomous communities. Thus, it has been necessary to reduce both the number of monitoring stations and the number of chemicals monitored. To achieve this, it is necessary to identify those monitoring stations and pollutants that are least significant, while minimizing the loss of data quality and mitigating the effects on the determination of any spatial and temporal trends of the pollutants. Through employing cluster analysis, it was established that the ambient monitoring stations in the Kanto region could be clustered topologically for NOx and O-x into eight groups. From the results of this analysis, it was possible to identify the similarities in site characteristics and pollutant behaviors.

ガイドラインでは、職業性アレルギー疾患は「誰の責任か?」というQuestionに始まり、労働衛生法令における、業務上疾病に対する事業者(使用者)の責任、職場での健康診断、療養・休業補償などの労災保険を取り上げた。本稿では、法律やその施行にあたる行政的な観点を加えて概説した。併せて、今後発見されるアレルギー要因による新規の疾患の認定にあたって、診断精度の向上と症例情報の収集に有用な職業性アレルギー疾患に対する「疾病登録」の構築についても考察を加えた。(著者抄録)

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. © 2013 John Wiley & Sons A/S.

既存の空気清浄手法に湿式法による臭気除去ユニットを加えた空気清浄装置（以下開発装置）について，臭気成分であるアセトアルデヒドを含むたばこ煙成分の除去効果をプロトン移動反応質量分析計（PTR-MS）により経時的に評価した。開発装置は，高性能除じんフィルター，活性炭フィルターから成る粉じん・VOC除去ユニット（Particulate and VOC Removal Unit : PVRU）の後段に新たに開発されたアミノ酸を含む薬液（化学吸収液）を用いた湿式の臭気除去ユニット（Odor Removal Unit : ORU）を配している。
実験ではアセトアルデヒドガスあるいはたばこ煙を開発装置に連続的に導入し，装置吸入口，PVRU後，ORU後（装置吹出口）の3点において試料空気中のアセトアルデヒド，たばこ煙成分および臭気濃度を測定し，各ユニットの除去効率を比較した。その結果，PVRU後では浮遊粉じん，ニコチンなど多くの揮発性有機化合物（VOC）の除去効果が認められたが，カルボニル化合物などの含酸素有機化合物と臭気の除去効果は不十分であり，アセトアルデヒドの除去率は時間経過とともに低下した。これに対してORU後ではアセトアルデヒドの95%が除去され，臭気は99%低減した。この効果はのべ400本のたばこ燃焼時まで持続し，薬液のアセトアルデヒド吸収容量は70 mg L^-1以上であった。

たばこ煙および臭気除去を目的として開発された空気清浄装置（開発装置）を備えた喫煙ブースを模擬オフィス内に設置し，開発装置によるたばこ煙処理空気を模擬オフィスに排出した際の，オフィス空間の空気質に及ぼす影響を評価した。評価は，喫煙ブース内で開発装置を稼働させ8本のたばこを連続的に同時燃焼し，オフィス空間の複数点においてたばこ煙成分濃度を測定した。その結果，各測定点におけるたばこ煙成分濃度は，たばこ燃焼前に比べて大きな変化は見られず，開発装置を備えた喫煙ブースの十分な分煙効果が認められた。ただし，開発装置で除去できない一酸化炭素（CO）は，たばこ煙発生に伴い開発装置吹出口の濃度が上昇したが，オフィス空間ではオフィス換気設備の稼働により速やかに低減した。次にオフィス換気の排気口をオフィス後部に設置した場合と開発装置吹出口の直上に設置した場合の2パターンで換気を行い，オフィス空間の評価物質濃度分布を調査したところ，両者で大きな差異は認められなかった。したがって，オフィス空間の気積に対し十分な換気量があれば，オフィス空間内の評価物質濃度は，室内濃度指針値等の基準値以下まで低減し，濃度分布も生じないことが示された。また，この結果と数値流体動力学（CFD）による解析結果とはよく一致したことから，開発装置を備えた喫煙ブースの導入前に非喫煙空間に及ぼす影響を推定することが可能であると考えられた。

The photo-Fenton reaction was applied as a novel method for the removal of volatile organic compounds (VOCs) in the gas phase, and its effectiveness was experimentally examined. In conventional VOCs removal methods using a photocatalyst or ozone, VOCs are oxidized in the gas phase. Therefore, incompletely oxidized intermediates, which may have adverse effects on health, are likely to contaminate the treated air. On the other hand, in the VOCs removal method developed in this study, because the VOCs are oxidized in the liquid phase by the photo-Fenton reaction, any incompletely oxidized intermediates produced are confined to the liquid phase. As a result, the contamination of the treated air by these harmful intermediates can be prevented. Using a semi-batch process, it was found that the removal efficiency for toluene in a one-pass test (residence time of 17 s) was 61%, for an inlet toluene gas concentration of 930 ppbv, an initial iron ion concentration of 20 mg L-1. and an initial hydrogen peroxide concentration of 630 mg L-1. The removal efficiency was almost constant as long as H2O2 was present in the solution. Proton transfer reaction mass spectrometry analysis confirmed the absence of any incompletely oxidized intermediates in the treated air. (C) 2012 Elsevier Ltd. All rights reserved.

ガス吸収と液相での酸化反応を組み合わせた気液接触型の新規空気清浄法の開発を行った。揮発性有機化合物（VOC）の酸化分解反応を液相で行うことにより，有害性のある不完全酸化分解生成物の室内空気中への放散を防ぐことができる。本研究では，液相での酸化分解反応としてフォトフェントン反応を用いた。フォトフェントン反応は鉄イオン，過酸化水素，光エネルギーを用いてOHラジカルを生成する反応である。生成したOHラジカルが液相中に溶解したVOCを酸化分解する。本プロセスは，気相中のVOCが液相へ物質移動し，フォトフェントン反応により分解されるため，気相中のVOCを連続的に除去できる。また，OHラジカルの反応性は非常に高く，水への溶解度の低い疎水性のVOCも，液相に物質移動した瞬間に分解されるため，疎水性のVOCも連続的に除去できる。本プロセスの有効性を評価するため，親水性と疎水性のVOCの除去実験を行った。実験では親水性VOCとしてアセトアルデヒド，疎水性VOCとしてトルエンを用い，ワンパス式で除去率を求めた。その結果，入口濃度1000ppb_vのアセトアルデヒドガスを97%以上，定常的に除去することができた。また，入口濃度1000ppb_vのトルエンガスの場合も50%程度，定常的に除去することができた。処理後のガス中の中間生成物をPTR-MSにより測定した結果，フォトフェントン反応を用いたVOCの酸化分解による不完全酸化分解生成物の放散がないことを確認した。

Experimental study was conducted on the simultaneous process of decomposition and fixation of fluoride of F-gases. HFC-134a, a hydrofluorocarbon (HFC), used most widely, was selected as a model gas, and its decomposition performances were examined in a tube type reactor with and without waste concrete powder. Decomposition of HFC-134a was observed at temperatures above 500 degrees C, while no thermal decomposition occurred below 750 degrees C without waste concrete. The results for the differential type reactor with high SV demonstrated that the calcium reaction ratio in the waste concrete reached about 50 mol % after 10 min of reaction. Thermal decomposition of HFC-134a was promoted by increasing the reaction temperature. The particle size of the waste concrete within the range studied scarcely affected the decomposition rate. An increase in HFC-134a concentration resulted in a higher calcium reaction ratio of waste concrete. For the integral reactor conditions with packed bed of waste concrete, almost all HFC-134a in the feed gas could be decomposed until 20 min of the reaction time.

Evaluation of air quality by concentration of just only target compounds has the possibility of a lot of trouble. In this study, we evaluated the air quality of new nursery room. As a result, the TVOC concentrations greatly exceeded the indoor target value (400 μg/m3). Moreover, we verified various ventilation methods such as continuous running of kitchen fan, securing of ventilation routes and introduction of additional ventilating fan, and the concentration drastically decreased to one-tenth compared with opening status after 3 months. In addition, ventilation rates estimated by TVOC concentration change of PID monitor increased.

A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources.

発泡ポリスチレンビーズ及び発泡ポリスチレンビーズを用いた製品からのスチレンの放散フラックスをPassive Flux Sampler（PFS）を用いて測定した。25℃において各試料からのスチレンの放散フラックスは11～220μg/m²/hであり 温度の上昇に伴って増加した。体温を想定した36℃では，スチレンの放散フラックスは32～620μg/m²/hであった。また，50℃では，203～2.23×10³μg/m²/hであった。アレニウスプロットから計算された各試料からのスチレン放散の見かけの活性化エネルギーの値は概ね100kJ/mol以下であった。ポリスチレン樹脂の熱分解反応の活性化エネルギーは210kJ/molと報告されている。そこで，試料からのスチレン放散の律速段階は，物質移動過程であると推測された。枕やクッション等の製品は呼吸域の近くで使用され，体温で暖められて放散量が多くなる可能性が高いため，これらの製品の使用によってスチレンへの曝露が生じることが懸念される。

While various volatile organic compounds (VOCs) are known to show neurotoxic effects, the detailed mechanisms of the action of VOCs on the autonomic nervous system are not fully understood, partially because objective and quantitative measures to indicate neural abnormalities are still under development. Nevertheless, heart rate variability (HRV) has been recently proposed as an indicative measure of the autonomic effects. In this study, we used HRV as an indicative measure of the autonomic effrects to relate their values to the personal concentrations of VOCs measured by a real-time VOC monitor. The measurements were conducted for 24 hours on seven healthy subjects under usual daily life conditions. The results showed HF powers were significantly decreased for six subjects when the changes of total volatile organic compound (TVOC) concentrations were large, indicating a suppression of parasympathetic nervous activity induced by the exposure to VOCs. The present study indicated these real-time monitoring was useful to characterize the trends of VOC exposures and their effects on autonomic nervous system.

Continuous measurements using proton transfer reaction mass spectrometry (PTR-MS) can be used to describe the production processes of secondary products during ozone induced oxidation of terpenes. Terpenes are emitted from woody building materials, and ozone is generated from ozone air purifiers and copy machines in indoor environments. Carbonyl compounds (CCs) are emitted by human activities such as smoking and drinking alcohol. Moreover, CCs are generated during ozone oxidation of terpenes. Therefore, coexistent CCs should affect the ozone oxidation. This study has focused on the measurement of secondary products during the ozone oxidation of terpenes based on the use of PTR-MS analysis and effects of coexistent CCs on oxidized products. Experiments were performed in a fluoroplastic bag containing alpha-pinene or limonene as terpenes, ozone and acetaldehyde or formaldehyde as coexistent CCs adjusted to predetermined concentrations. Continuous measurements by PTR-MS were conducted after mixing of terpenes, ozone and CCs, and time changes of volatile organic compounds (VOCs) concentrations were monitored. Results showed that, high-molecular weight intermediates disappeared gradually with elapsed time, though the production of high-molecular weight intermediates was observed at the beginning. This phenomenon suggested that the ozone oxidation of terpenes generated ultrafine particles. Coexistent CCs affected the ozone oxidation of alpha-pinene more than limonene.

The irreversible removal of acetaldehyde from indoor air via a chemical reaction with amino acids was investigated. To compare effectiveness, five types of amino acid (glycine, L-lysine, L-methionine, L-cysteine, and L-cystine) were used as the reactants. First, acetaldehyde-laden air was introduced into aqueous solutions of each amino acid and the removal abilities were compared. Among the five amino acids, L-cysteine solution showed much higher removal efficiency, while the other amino acids solutions didn't show any significant differences from the removal efficiency of water used as a control. Next, as a test of the removal abilities of acetaldehyde by semi-solid L-cysteine, a gel containing L-cysteine solution was put in a fluororesin bag filled with acetaldehyde gas, and the change of acetaldehyde concentration was measured. The L-cysteine-containing gel removed 80% of the acetaldehyde in the air within 24 hours. The removal ability likely depended on the unique reaction whereby acetaldehyde and L-cysteine rapidly produce 2-methylthiazolidine-4-carboxylic acid. These results suggested that the reaction between acetaldehyde and L-cysteine has possibilities for irreversibly removing toxic acetaldehyde from indoor air.

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 mu g/m(2)/h). whereas fluxes from a door and flooring were low (21.5 and 16.5 mu g/m(2)/h. respectively). The emission fluxes of toluene from the ceiling and the carpet were high (80.0 and 72.3 mu g/m(2)/h, respectively), whereas that from the flooring was low (9.09 mu g/m(2)/h). The indoor and outdoor concentrations of formaldehyde were 61.5 and 8.64 mu g/m(3), respectively, and those of toluene were 43.2 and 17.5 mu g/m(3), 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). (C) 2008 Elsevier Ltd. All rights reserved.

To characterize potential air pollution issues related to recycling facilities of waste plastics, volatile organic compounds (VOCs) emitted from melted virgin and waste plastics pellets were analyzed. In this study, laboratory experiments were performed to melt virgin and waste plastic pellets under various temperatures (150, 200, and 250 degrees C) and atmospheres (air and nitrogen [N(2) ]). In the study presented here, low-density polyethylene (LIVE), polypropylene (PP), polystyrene (PS) and the recycled waste plastic pellets were used. The VOCs generated from each plastic pellets were collected by Tenax/Carboxen adsorbent tubes and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS).The result showed the higher temperatures generated larger amounts of total VOCs (TVOCs).The VOCs emitted from the virgin plastic pellets likely originated from polymer degradation, Smaller TVOC emissions were observed in N(2) atmosphere than in air atmosphere. In particular, larger amounts of the oxygenated compounds, which are generally hazardous and malodorous, were detected in air than in N(2). In addition to the compounds originating from polymer degradation, the compounds originating from the plastic additives were also detected from LDPE and PS. Furthermore, various species of VOCs likely originating from contaminant inseparate polyvinyl chloride (PVC), food residues, cleaning agents, clegreasers, and so on were detected from the waste plastic. Thus, melting waste plastics, as is conducted in recycling facilities, might generate larger amounts of potentially toxic compounds than producing virgin plastics.

While various VOCs are known to show neurotoxic effects, the detailed mechanisms of VOCs on autonomic nervous system have not been fully understood partly because objective and quantitative measures to indicate neural abnormalities are still under development. Nevertheless, heart rate variability (HRV) has been recently proposed as an indicative measure of the autonomic defect. In this study, we used HRV as an indicative measure of the autonomic defect to relate their values to the personal concentrations of VOCs measured by a real-time VOC monitor. The measurements were conducted to 7 healthy subjects for 24 hours. The results showed HF powers were decreased for 6 subjects when the TVOC concentration changes were high, indicating the suppression of parasympathetic nervous induced by the exposure to VOCs. The present study indicated these real-time monitoring was useful to characterize the trends of VOC exposures and their effects on autonomic nervous system. Application of the present method is expected to lead to diagnosis and cure for the patients such as MCS and sick building syndrome in the future.

化学物質不耐症患者の呼気中化学物質濃度を測定し、健康影響の評価に応用できるかを検討した。調査対象者は健常者6名と化学物質不耐症患者26名、対象者から呼気を約1.0L採取し、加熱脱着ガスクロマトグラフ質量分析計にて6種類の揮発性有機化合物(以下、VOC)を測定した。化学物質不耐症患者の病態評価は問診と神経眼科的検査、アンケート調査により評価した。化学物質不耐症患者の呼気中ベンゼン、p-ジクロロベンゼン、イソプレン、リモネン、トルエンは、それぞれ健常者の値に比較して高い傾向が認められ、このうちトルエン濃度は健常者に比較して2倍の高値を示した(p<0.01)。今後、呼気中VOC測定は、化学物質不耐症患者の病態や生体影響の評価に役立つ可能性を明らかにした。(著者抄録)

Multiple chemical sensitivity (MCS) has become a serious problem as a result of airtight techniques in modern construction. The mechanism of the MCS, however, has not been clarified. Responsible chemicals and their exposure levels for patient's hypersensitive reactions need to be identified. We measured the exposure of 15 MCS patients to both carbonyl compounds and volatile organic compounds (VOCs) that may induce hypersensitive reactions. The exposures of those not suffering from MCS (non-MCS individuals) were also measured at the same time. To characterize the chemicals responsible for MCS symptoms, we applied a new sampling strategy for the measurement of carbonyls and VOCs using active and passive sampling methods. The results of our study clearly demonstrated that the chemicals responsible for such hypersensitive reactions varied from patient to patient. Moreover, the concentrations during hypersensitive symptoms, which were apparent in some of the MCS patients, were far below both the WHO and the Japanese indoor guidelines. The average exposure levels of MCS patients within a 7-day period were lower than those of paired non-MCS individuals except for a few patients who were exposed to chemicals in their work places. This result indicates that the MCS patients try to keep away from exposures to the chemical compounds that cause some symptoms.

環境過敏症は、通常、問題にならない僅かなレベルの化学物質への曝露や物理的影響などの環境因子により、全身の様々な症状が生じる病態である。近年、生活環境は急速に変化し、コロナ禍も相まって、環境過敏症の発症や病態に関係する環境因子は多様化している。そこで本研究では、環境過敏症に関係する環境因子を把握するための質問票を開発し、質問票を用いた実態調査を行うことで、環境過敏症の症状を訴える人の割合や発症・症状発現に関係する環境因子、日常生活における環境バリアを明らかにすることを目的としている。 本年度は引き続き文献調査を基に質問票を精査し、環境過敏症の発症と病態の機序を明らかにすることに主眼を置いて、発症の原因（きっかけ）と症状を誘発する環境因子について明確に区別して回答が得られるように改変した。また、環境過敏症の発症予防に関する最新の研究の情報を集約するため、日本臨床環境医学会および室内環境学会の環境過敏症分科会と生活環境と健康研究会の主催で合同研究会を2回オンラインにて開催し、研究会での情報、議論を質問票に反映させた。上記の作業から派生して、環境過敏症に関する国際共通の質問票やそれらを用いた調査研究、環境過敏症の定義や仮説についてまとめた総説が日本自律神経学会の学会誌「自律神経」に掲載された。また、次年度発刊の室内環境学会誌「室内環境」に特集「マルチ異分野の研究者からみた室内環境と環境過敏症：科学的究明と発症予防を目指して」の企画をした。

PVCシートからの放散量やシート状の気中濃度を把握するために、複数の拡散距離（0.9, 1.85, 2.75, 3.8, 5.75 mm）でPFSによる放散量測定を行った。 建材上に複数の拡散距離（0.9, 1.85, 2.75, 3.8, 5.75 mm）がある場合のダストから粒子への移行と気中への放散を測定する試験には、JIS 試験用粉体 1（15種）の標準ハウスダストを用い、ダスト設置の1,3,7,14日後にダストを回収した。ハウスダストは、180 μmの篩に掛けて0.3, 1.0, 3.0, 12 mg/cm2で塩ビシート上に均一に撒いて試験した。 異なる粒子への移行を評価するために、ポリエチレン粒子（CPMS; 比重 0.96; 径1-10, 45-53, 90-106 μm））とソーダライムガラス粒子（SLGMS; 比重 2.5; 径1-38, 45-53, 90-106 μm）を用いた。拡散距離は5.75 mmとし、1,3,7,14日後にダストを回収した。 PVCシートからハウスダストへのDEHPの移行量は、経時的に増加していたが、徐々に吸着が飽和に近づいて増加量は減少していた（図3）。また、PVCシート表面のダスト量が少ないほど、重量当たりのダストへのDEHPの移行量が大きかった。ダスト上の空気層の厚さによる違いはみられなかった。PVCシートの面積当たりの移行量は、粒子量が多いほど大きかったが、14日後で20～40 μg/cm2と、2倍程度の違いしか見られなかった。 PVCシート上のダスト量が3, 12 mg/cm2の場合には、ダストへの吸着のために7日後や14日後まで放散量が非常に小さかったが、ダスト量が1, 0.3 mg/cm2の場合には、ダストがない場合と同様に線形の経時的な増加を示した。ダストへの移行量は、気中への放散量より数10～数100倍高かった。

廃プラスチックマテリアルリサイクルによる排ガスの大気化学反応の究明と処理法の検証を目的とし、本年度はフィールドにおける大気化学反応の寄与の調査と実験によるVOC処理技術の検証を行った。フィールド調査では、夏季（6月）に施設付近（約800 m）で大気中ホルムアルデヒド濃度を電気化学的燃料電池法の連続測定器によりモニタリングした。また、常時監視測定局（一般局）の同時期における光化学オキシダント、PM2.5、NMHC、NO2の濃度と日射量を参照した。その結果、ホルムアルデヒド濃度は8～10時頃から上昇し、午後にピークを迎え、深夜にかけて減少した。この変動は、一般局のNMHC、NO2濃度とは異なる傾向で、日射量と光化学オキシダント濃度と連動しており、日射量と光化学オキシダント濃度上昇の後、ホルムアルデヒド濃度が上昇していた。これは同地域における既往の調査と同様の傾向であり、光化学反応がホルムアルデヒドの生成に寄与していることが示唆された。 次に、湿式酸化促進法を用いた気中VOCの分解除去の検証を行った。VOCは、近年、室内汚染物質として注目されている2-エチル-1-ヘキサノール(2E1H)を対象とした。フォトフェントン反応を用いた除去法により、3ppmの2E1Hをワンパスで85%以上除去可能であった。除去後の出口ガスにはアセトアルデヒドなど酸化分解生成物が導入ガス濃度の2%程度確認された。 研究全体では、プラスチック溶融時発生物質を実験により把握し、フィールドにて大気化学反応によるホルムアルデヒド生成の可能性を示し、湿式酸化促進法によるVOC除去可能性を実証することができたため、廃プラスチックマテリアルリサイクルにおいて排出される化学物質の挙動や処理法についての情報が集積されたと考える。また、一連の実験・調査方法は、排出化学物質の挙動把握のための汎用的手法として期待できるといえる。

木材腐朽は，木材の強度低下による木造構造物の崩壊リスクの増加及び変色や着色による製品価値の低下につながり，経済的損失の主な原因と考えられる。微生物由来の揮発性代謝産物（MVOC）は隠れた場所の木材腐朽菌の検出に利用できる可能性がある。本研究では，3種類の分析手法によって木材腐朽菌が放散するMVOCを分析し，各々の分析手法の特徴を明らかにした。また，木材の腐朽段階と腐朽菌によって産生されるMVOCとの関係についての知見が得られた。これにより，木材腐朽の早期発見のために木材腐朽菌の存在を標識するトレーサーとしてMVOCを使用できることが示された。

SVOCの経皮経路の暴露評価を目標とし、必要な情報のうち、特に、皮膚移行、皮膚吸収に関わる暴露係数に注目してデータの収集・整理した。現存する暴露評価モデルやツールに基づき、必要となる暴露係数をリストアップして、文献調査により報告値をまとめた。事例研究としてこれらの値を用いて暴露シナリオを想定し、リスク評価を行った。また、より正確なSVOCの経皮経路の暴露評価を行うための今後の課題についてまとめた。

有機リン化合物は、殺虫剤や難燃剤として汎用されているが、遅延性の神経障害をもつことがわかり、化学物質過敏症の原因としても懸念されている。そこで、本研究では、実環境で有機リン化合物の放散量がわかる測定器を開発した。有機リン化合物の毒性メカニズムである酵素阻害反応を利用し、発色させて視覚的に放散量を把握できるものとした。6時間サンプリングで吸光度測定による検出が可能であり、24時間サンプリングで目視による判定が可能である。