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Background Our hypothesis was that exposure to fine particulate matter (PM2.5) is related to abnormal cord insertion, which is categorized as a form of placental implantation abnormality. We investigated the association between exposure to total PM2.5 and its chemical components over the first trimester and abnormal cord insertion, which contributes to the occurrence of adverse birth outcomes. Methods From the Japan Perinatal Registry Network database, we used data on 83 708 women who delivered singleton births at 39 cooperating hospitals in 23 Tokyo wards (2013–2015). We collected PM2.5 on a filter and measured daily concentrations of carbon and ion components. Then, we calculated the average concentrations over the first trimester (0–13 weeks of gestation) for each woman. A multilevel logistic-regression model with the hospital as a random effect was used to estimate the odds ratios (ORs) of abnormal cord insertion. Results Among the 83 708 women (mean age at delivery = 33.7 years), the frequency of abnormal cord insertion was 4.5%, the median concentration [interquartile range (IQR)] of total PM2.5 was 16.1 (3.61) μg/m3 and the OR per IQR for total PM2.5 was 1.14 (95% confidence interval = 1.06–1.23). In the total PM2.5-adjusted models, total carbon, organic carbon, nitrate, ammonium and chloride were positively associated with abnormal insertion. Organic carbon was consistently, and nitrate tended to be, associated with specific types of abnormal insertion (marginal or velamentous cord insertion). Conclusions Exposure to total PM2.5 and some of its components over the first trimester increased the likelihood of abnormal cord insertion.

PMData were obtained from the Japan Perinatal Registry Network database, which includes all live births and stillbirths after 22 weeks of gestation at 39 cooperating hospitals in 23 Tokyo wards (2013-2015). At one fixed monitoring site, we performed daily filter sampling of fine particles and measured daily concentrations of carbon and ion components. The average concentrations of total PMAmong 82,773 women (mean age at delivery = 33.7 years) who delivered singleton births, 3,953 (4.8%) had GDM. In the multiexposure period model, an association between total PMThis is the first evidence that exposure to total PM

A portable emission measurement system (PEMS) was used to measure the real-world driving emissions pertaining to a Japanese middle-sized heavy-duty vehicle. The testing was performed with the vehicle being driven in the metropolitan area of Tokyo in four seasons (January, June, August, and November) to analyze the seasonal dependence of NOx and CO2 emissions. The experimental results indicated that the amount of NOx emissions was particularly high in the cold season owing to the slow starting of the NOx after-treatment systems, which is to say the exhaust gas recirculation and urea-selective-catalytic-reduction systems, under low-ambient-temperature conditions. In real-world driving, a high acceleration pattern was observed in the low-speed region which is not considered in the world harmonized vehicle cycle, which is the worldwide official driving mode in the chassis dynamometer experiment. Finally, the transient emission tables for NOx and CO2 were constructed based on the PEMS measurement results and the classical mechanic theory. The constructed tables replicated well the experimental results in all the considered conditions involving different ambient temperatures and locations. The proposed approach can be used to evaluate emission inventories in the future.

Background Maternal exposure to fine particulate matter (PM2.5) was associated with pregnancy complications. However, we still lack comprehensive evidence regarding which specific chemical components of PM2.5 are more harmful for maternal and foetal health. Objective We focused on exposure over the first trimester (0–13 weeks of gestation), which includes the early placentation period, and investigated whether PM2.5 and its components were associated with placenta-mediated pregnancy complications (combined outcome of small for gestational age, preeclampsia, placental abruption, and stillbirth). Methods From 2013 to 2015, we obtained information, from the Japan Perinatal Registry Network database, on 83,454 women who delivered singleton infants within 23 Tokyo wards (≈627 km2). Using daily filter sampling of PM2.5 at one monitoring location, we analysed carbon and ion components, and assigned the first trimester average of the respective pollutant concentrations to each woman. Results The ORs of placenta-mediated pregnancy complications were 1.14 (95% CI = 1.08–1.22) per 0.51 μg/m3 (interquartile range) increase of organic carbon and 1.11 (1.03–1.18) per 0.06 μg/m3 increase of sodium. Organic carbon was also associated with four individual complications. There was no association between ozone and outcome. Significance There were specific components of PM2.5 that have adverse effects on maternal and foetal health.

Intermediate volatility and semivolatile organic compounds (IVOC/SVOC) are important precursors of secondary organic aerosol (SOA) while SVOC is an important contributor to primary organic aerosol (POA). However, combustion emissions data for volatility classes are limited. This study reports the gas and particle emissions that were sampled with various dilution factors from a sewage sludge incinerator burning fuel oil. Volatility distributions were determined using measurements from online mass spectrometry and offline organic compound analyses. In the low volatility organic compound (LVOC) to IVOC range, volatility bins with organic saturation concentrations of 10-100 μg m-3 were most abundant, which was due to organic acids generated from sludge burning. Organic aerosol (OA) emission factors (EFOA) increased 1.4 times after cooling to ambient temperatures in comparison to those of the samples from the hot stack. Upon further isothermal dilution at 25 °C, the EFOA decreased while organic gas phase EFs increased with increasing dilution. Phase partitioning in volatility bins with saturation concentrations of 10-100 μg m-3 was sensitive to isothermal dilution that influenced the EFs. Therefore, gas- and particle-phase measurements alone cannot constrain EFs for these volatility classes. Low dilution factors may overestimate the particle phase and underestimate the gas phase EFs compared with real-world emission conditions.

Despite the worldwide trend of introducing of zero-fuel-based vehicles to the market, the emissions of air pollutants and greenhouse gases from passenger vehicles are likely to remain a concern for the coming 20 to 30 years. In this study, exhaust emissions of gasoline engines running after varying parking durations were measured using a chassis dynamometer. The experimental results showed that exhaust emissions of hydrocarbons, nitrogen oxides, and carbon monoxide from most vehicles increased dramatically following 60 to 120 min of parking, and were higher than cold-start (1040 + min parking) emissions, indicating the impact of parking duration on atmospheric pollutant emissions. The after-treatment capacity of the three-way catalytic converter was evaluated by chemical kinetic modeling of the chemical reactions on the catalyst coupled with a time-dependent energy conservation equation. The results of the model calculation indicated that both the initial temperature of the three-way catalytic converter and the inlet engine gas temperature are critical factors impacting exhaust pollutants after parking; therefore, proper management to reduce the emissions after middle-term parking durations should be developed to mitigate air pollution.

Objective We investigated which trimester of exposure to PM2.5 and its components was associated with birth and placental weight, and the fetoplacental weight ratio. Methods The study included 63,990 women who delivered singleton term births within 23 Tokyo wards between 2013 and 2015. Each day, we collected fine particles on a filter, and analyzed their chemical constituents, including carbons and ions. Trimester-specific exposure to each pollutant was estimated based on the average daily concentrations. Results Over the third trimester, sulfate exposure tended to be inversely associated with birth weight, and decreased placental weight (difference for highest vs lowest quintile groups = -6.7 g, 95% confidence interval = -12.5 to -0.9). For fetoplacental weight ratio, there was no relationship. Conclusions Sulfate exposure over the third trimester may reduce birth weight, particularly placental weight.

Concentrations of PM2.5 in Tokyo, a densely populated megacity, often increase because of NH4NO3 formation under low-wind conditions during winter. To obtain source information of NH3 as a NH4NO3 precursor, hourly NH3 and NH4^+ concentrations were measured at an urban site in Tokyo in December 2017. Results show that PM2.5 and NH4^+ concentrations increased simultaneously under low-wind and low-temperature conditions along with NH3, NOx, CO, and optical black carbon (OBC) concentrations. The remaining NH4^+ (herein, ΔNH4^+) subtracted from observed NH4^+ to equivalent SO4^2− concentration correlated well with NO3^− in PM2.5, indicating the existence of fine NH4NO3 particles. Regression analysis of hourly NH3 + ΔΝH4^+ concentrations with CO, NOx, and OBC showed significant correlation. Virtual emission rates (VER) of NH3 per motor vehicle in Tokyo were estimated using observed relations between NH3 + ΔΝH4^+ and OBC, etc. with data from vehicular statistics: they were 3.7–32 mg/km. The regression of NH3 + ΔΝH4^+ with OBC concentrations indicated an intercept of about 3.2 ppb, which is about half of the monthly average in December. This result implies that the non-vehicular source strength was nearly the same strength as the bulk vehicular emissions of NH3 during winter in Tokyo., ファイル公開：2021-06-01

Alkenes and aromatics significantly contribute to the photochemical reactions in the Kanto Region, where the level of ozone frequently exceeds the level for photochemical smog warnings in summer. The major aromatic sources have been cataloged in the Pollutant Release and Transfer Register (PRTR) database in Japan; however, the major alkene sources are not included. We investigated the hourly variations in the volatile organic compound (VOC) concentrations at four sampling sites in the Tokyo Bay coastal area, which has a variety of VOC sources, including the petrochemical industry, chemical facilities, iron–steel plants, and refineries. The 116-component VOC data were used to conduct a positive matrix factorization (PMF) analysis to apportion the VOC sources; then, the source regions were estimated by combining the concentration ratios of the factors with the wind direction data. We used the hourly VOC data for the PMF analysis because alkenes are short-lived. Six factors were estimated using the PMF method and identified as liquefied petroleum gas + industry, aged air mass, fuel evaporation, petrochemical industry, aromatics, and solvent usage. The mean contribution ratios of these six factors were 8.9%, 19.9%, 9.3%, 10.4%, 9.9%, and 14.0%, respectively, whereas the mean contribution ratio of the residual was 27.7%. By combining the alkene concentration and factor contribution ratios with the wind direction, the petrochemical industry in the Kawasaki coastal area was demonstrated to be the main alkene source. In addition, the petrochemical industry makes the largest contribution to ozone production according to the OH radical loss rates of the six factors.

A portable emission measurement system (PEMS) was used to measure the real-world driving emissions pertaining to a Japanese middle-sized heavy-duty vehicle. The testing was performed with the vehicle being driven in the metropolitan area of Tokyo in four seasons (January, June, August, and November) to analyze the seasonal dependence of NOx and CO2 emissioans. The experimental results indicated that the amount of NOx emissions was particularly high in the cold season, owing to the slow starting of the NOx detoxification systems, that is, the exhaust gas recirculation and urea-selective-catalytic-reduction systems, under low ambient temperature conditions. In the real-world driving, a high acceleration pattern was observed in the low-speed region, which is not considered in the world harmonized vehicle cycle, which is the worldwide official driving mode in the chassis dynamometer experiment. Finally, the transient emission tables for NOx and CO2 were constructed based on the PEMS measurement results and the classical mechanic theory. The constructed tables well replicated the experimental results in all the considered conditions involving different ambient temperatures and locations. The proposed approach can be used to evaluate emission inventories in the future.

Ozone concentration in Tokyo Metropolitan area is one of the most serious issues of the local air quality. Tropospheric ozone is formed by radical reaction including volatile organic compound (VOC) and nitrogen oxides (NOx). Reduction of the emission of reactive VOC is a key to reducing ozone concentrations. VOC is emitted from anthropogenic sources and also from vegetation (biogenic VOC or BVOC). BVOC also forms ozone through NOx and radical reactions. Especially, in urban area, the BVOC is emitted into the atmosphere with high NOx concentration. Therefore, trees bordering streets and green spaces in urban area may contribute to tropospheric ozone. On the other hand, not all trees emit BVOC which will produce ozone locally. In this study, BVOC emissions have been investigated (terpenoids: isoprene, monoterpenes, sesquiterpenes) for 29 tree species. Eleven in the 29 species were tree species that did not emit BVOCs. Three in 12 cultivars for future planting (25%) were found to emit no terpenoid BVOCs. Eight in 17 commonly planted trees (47%) were found to emit no terpenoid BVOC. Lower-emitting species have many advantages for urban planting. Therefore, further investigation is required to find the species which do not emit terpenoid BVOC. Emission of reactive BVOC should be added into guideline for the urban planting to prevent the creation of sources of ozone. It is desirable that species with no reactive BVOC emission are planted along urban streets and green areas in urban areas, such as Tokyo.

High concentrations of tropospheric ozone remain a concern, and strategies to reduce the precursors of ozone, volatile organic compounds (VOCs) and nitrogen oxides, have been established in many countries. In this study, chassis dynamometer experiments were conducted for 25 late model gasoline passenger vehicles in the Japanese market to evaluate VOC emission trends. Tailpipe emissions were collected and analyzed using gas chromatography mass spectrometer and flame ionization detector, and liquid chromatography&ndash, mass spectrometry (LC-MS). Results showed that tailpipe VOC emissions increased linearly with vehicle mileage due to deterioration of the three-way catalysis converter used to purify the toxic components in vehicle emissions. Distance normalized total VOC emissions showed that port injection mini-sized vehicles were effective in decreasing tailpipe VOC emissions because of their low vehicle weight. The VOC composition of tailpipe emissions was dependent on the fuel type (regular or premium gasoline). VOC emissions from hybrid vehicles were similar to those of other vehicles because cooling of the three-way catalysis converter during battery operations sometimes tended to reduce catalyst effectiveness during engine operations. However, it can also be assumed that each manufacturer is aware of this phenomenon and is taking action. Further monitoring of hybrid vehicles is warranted to ensure that these vehicles remain an effective means of mitigating air pollution.

Fine particulate matter (PM2.5) is composed of a variety of chemical components, and the dependency of the health effects of total PM2.5 on specific components is still under discussion. We hypothesised that specific PM2.5 components are responsible for the health effects, and investigated the association between PM2.5 components and mortality in 23 Tokyo wards. We obtained mortality data from the Ministry of Health, Labour and Welfare for the period from April 2013 to March 2017. At a monitoring site within the study area, we collected daily samples of PM2.5 on a filter, and determined the daily mean concentrations of total carbon (organic carbon and elemental carbon) and ions such as nitrate and sulphate. A case-crossover design was employed, and a conditional logistic regression model was used to estimate the strength of the association. Over the study period, we identified 280,460 total non-accidental deaths, and the average daily mean concentration of total PM2.5 was 16.0 (standard deviation = 8.9) μg/m3. We observed a positive association of total PM2.5 with total, cardiovascular, and respiratory mortality. After adjustment for total PM2.5 and its components associated with mortality in the single-component models, the percentage increase per interquartile range (2.3 μg/m3) increase in the average total carbon concentration of the case- and previous-day was 2.1% (95% confidence interval = 1.0 to 3.1%) for total mortality. Carbon elements were associated with respiratory but not cardiovascular mortality. Our results suggest that specific components of PM2.5 account for its adverse health effects.

Nitrous acid (HONO) plays an important role in the formation of OH radicals, which are involved in photochemical oxidation. HONO concentrations in ambient air at urban sites have previously been measured, but very few studies have been performed in central Tokyo. In this study, HONO concentrations in ambient air in southeast central Tokyo (near Tokyo Bay) in winter were determined by incoherent cavity enhanced absorption spectroscopy. The O3, NO, NO2, and SO2 concentrations were simultaneously determined. The NO concentrations were used to classify the parts of the study period into types I (high pollution), II (medium pollution), and III (low pollution). The maximum HONO concentrations in the type I, II, and III periods were 7.1, 4.5, and 3.0ppbv, respectively. These concentrations were comparable to concentrations previously found in other Asian megacities. The mean HONO concentration varied diurnally, and HONO was depleted between 00:00 and 03:00 each day. The sampling site is surrounded by roads with high traffic loads, but vehicular emissions were estimated to contribute

Atmospheric concentrations of 52 hydrocarbons and two aldehydes at roadside and urban sites in Tokyo metropolitan area, Japan were analyzed using GC/MS and HPLC. Monthly sampling was conducted during April 2003–March 2005. Annual average concentrations of individual volatile organic compounds (VOCs) at the roadside site were 1.7–1.9 times higher than at the urban site, suggesting that vehicle exhausts strongly affect VOC concentrations. Since high temperatures and under the stagnant meteorological conditions might increase VOC concentrations in air, the levels of alkanes, alkenes, and aromatic hydrocarbons rose in summer and autumn in 2003 and 2004. The VOCs concentrations against benzene (VOCs/Bz) suggest classifying three groups of VOCs: those mainly from mobile emission sources, those mainly from stationary sources, and those comprising unstable compounds such as aldehydes and 1,3-butadiene. The VOC/Bz technique was applied to registered VOC data from the Pollutant Release and Transfer Register (PRTR). Results show that these VOCs in ambient air in Tokyo reflect the PRTR estimated release amounts. The VOC/Bz technique based on environmental monitoring data is useful to estimate non-registered VOCs such as butane and isopentane. Results show the possibility of estimating emission sources using VOC/Bz ratios from environmental monitoring data, even when sufficient information on the emission sources are not available.

試料平均化装置およびGC/MSを用いた自動分析装置によって, 大気中の揮発性有害大気汚染物質の連続測定を行い, 手分析による測定値と比較した。自動分析装置による測定可能物質は38物質であったが, このうち大気中から検出された26物質について連続測定および手分析の整合性評価を行った。1ヶ月以上の連続測定の期間中, ほとんどの物質で保持時間は安定であり, 内部標準物質 (フルオロベンゼン) のイオン強度比 (確認イオン/定量イオン) も安定であった。手分析との比較では, 検出された物質の約6割はおおむね自動分析装置の測定値は手分析と整合性がとれた値となった。しかし, ジクロロメタン等の数物質では今後, さらに検討が必要であった。また, 自動分析装置と手分析の測定値の相関係数は, フロン類等の大気中濃度が殆ど変化しない5物質を除くと多くの物質で高い値であった。

大気中に微量存在する揮発性有害大気汚染物質の濃度を, キャピラリーカラムGC/MSで長期間観測するための自動分析装置を開発した。大気試料は, 数時間～1日毎の平均濃度を測定するように, ステンレス製試料採取容器に定流量で加圧採取した。測定値に連続性を持たせるために, 2つの容器に交互に試料採取した。健康影響評価に必要とされる年平均濃度を効率よく求めるために, 1日毎に試料を平均的に採取することにし, 装置の基本性能について検討した。

Atmospheric Environment 49 (2012) 51e59 Contents lists available at SciVerse ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv Air quality diagnosis from comprehensive observations of total OH reactivity and reactive trace species in urban central Tokyo Ayako Yoshino a, * , Yoshihiro Nakashima a , Koji Miyazaki a , Shungo Kato a , Jeeranut Suthawaree a , Nobuo Shimo b , Sou Matsunaga b , Satoru Chatani b, c , Eric Apel d , James Greenberg d , Alex Guenther d , Hiroyuki Ueno e , Hiroyuki Sasaki e , Jun-ya Hoshi e , Hisashi Yokota e , Koichiro Ishii e , Yoshizumi Kajii a a Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan Auto Oil and New Fuels Department, Japan Petroleum Energy Center, 4-3-9 Toranomon, Minato-ku, Tokyo 105-0001, Japan Toyota Central RD Tajima et al., 2010). The concen- tration of NO x (NO x ¼ NO þ NO 2 ) and non-methane hydrocarbons (NMHCs) has decreased by 10%e20%, while in contrast, O 3 has increased by 2% per year between 1992 and 2002 in Japan (Akimoto, 2006). Tropospheric O 3 makes a significant contribution to global warming because of its large radiative forcing, which is nearly equal to that of methane (CH 4 ). Thus there is a need within * Corresponding author. Present address: Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan. Tel./ fax: þ81 42 367 5620. E-mail address: ayoshino@cc.tuat.ac.jp (A. Yoshino). 1352-2310/$ e see front matter O 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2011.12.029 the atmospheric science community to investigate the cause of this increase in tropospheric O 3 . Recent research has suggested that factors responsible for this increase in O 3 may include the presence of unknown VOCs (Sadanaga et al., 2005; Kajii et al., 2006) which facilitate highly efficient O 3 production following the decrease in NO x , the acceleration of O 3 production by the heat island phenom- enon, and the transport of O 3 and its precursors from the Asian continent (Ohara and Sakata, 2003). However, the most significant causative factors of this increase in O 3 in the urban atmosphere have yet to be identified. In order to completely understand the mecha- nism of tropospheric O 3 production, simultaneous observations of all the precursors of O 3 and an understanding of their reaction pathways are necessary, but this is not a practical approach. A great number of reactions contribute to the formation of tropospheric O 3 . Lewis et al. (2000) reported that there are more than several hundred kinds of VOCs in the troposphere, and Goldstein and Galbally (2007) reported that there are probably more than 10 5 different VOCs in the troposphere, which underscores the difficulty in fully characterizing all tropospheric O 3 reaction pathways.