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Background. Allergic fungal airway diseases, such as asthma and allergic bronchopulmonary mycosis (ABPM), are often difficult to manage with medical treatment alone; therefore, environmental fungal exposure should be accurately evaluated and minimized. In the present study, we established a method to evaluate and eliminate fungal contamination in household air conditioners (ACs). Methods. In the fall of 2020, an environmental survey of living rooms was conducted in 17 Japanese residences of patients with ABPM or related diseases. Household ductless minisplit AC units were disassembled to collect swab samples from the internal parts (filter, heat exchanger, blower fan, and air vent), followed by high-pressure washing. Fungal abundance and composition in swab samples and cleaning effluents of ACs as well as house dust and air samples were determined using quantitative PCR and next-generation sequencing of the internal transcribed spacer 1 region, respectively. A weighted UniFrac distance was calculated to analyze the similarity of the mycobiome among the samples. Results. All interior parts of ACs contained high levels of fungal DNA, with the blower fans being the most contaminated parts. Cladosporium and Toxicocladosporium, followed by Aureobasidium, Aspergillus, and Rhodotorula, were the most common fungi detected in the AC unit. High-pressure washing decreased fungal abundance by over 99% in all AC parts. Fungal abundance and composition in blower fans were strongly correlated with those in cleaning effluents. Conclusion. Interior parts downstream of heat exchangers in household ACs are the major sites of fungal contamination, possibly polluting the indoor air in the residences. High-pressure washing is highly effective for decontamination.

Oxidative stress induced by fine particulate matter 2.5 (PM2.5) is a potential cause of adverse health effects owing to the production of reactive oxygen species (ROS). Air filtration is a key technology for preventing exposure to particulate contaminations; however, particulate matter trapped by filters has the potential risk of human contact with condensed PM2.5. Thus, this study aims to reduce the hydroxyl radical (·OH) production potential of PM2.5 collected on such TiO2-supporting quartz filters. The ·OH production potential was evaluated for PM2.5, which was collected in Kanagawa, Japan, using a terephthalate assay coupled with flow injection analysis. Although the PM2.5 levels at the sampling site were not severe, the PM2.5 samples exhibited ·OH production potential, which was mostly attributed to organic aerosols. The effect was verified using a TiO2-supporting quartz filter for the collection and subsequent degradation of PM2.5. The ·OH production potential was significantly reduced from 0.58 ± 0.40 pmol/(min m3) to 0.22 ± 0.13 pmol/(min m3) through ultraviolet irradiation for 24 h. This suggests that the photocatalytic reaction of the TiO2 filter is effective in reducing the ·OH production potential of PM2.5.

Skin volatile organic compounds (VOCs) can cause body odor or reveal human disease and may result from lipid peroxidation or activity by skin bacteria. We examined the effect of intake of New Zealand blackcurrant (NZBC) powder for 77 skin VOCs in middle-aged and older adults in a crossover design. Fourteen adults (nine males, age: 55 ± 5 yrs) consumed NZBC powder for 7 days (6 g·day−1 with 138.6 mg anthocyanins). Two hours after the last intake, a passive flux sampler with trapping media was applied in the base of the neck for 1 hour. Gas chromatography-mass spectrometry was used for media analysis. Habitual anthocyanin intake was quantified using a food frequency questionnaire. Compared to control (i.e., no intake of NZBC powder), emission of six skin VOCs (i.e., 2-nonenal, acetic acid, 2-hexanone, 6-methyl-5-hepten-2-one, benzaldehyde, allyl methyl sulfide) were lower by more than 25%. Increases were observed for γ-octanolactone (+184%) and γ-decanolactone (+89%). A trend for a decrease for isovaleraldehyde, hexanal, and 2-pentanone, and an increase for heptanoic acid and γ-nonanolactone was observed. There was a significant correlation with daily habitual dietary anthocyanin intake for control values of hexanal and percentage change of γ-octanolactone. NZBC powder can change emanation of some VOCs in human skin. Analysis of skin VOCs following specific polyphenol intake may address the impact of dietary components to affect internal metabolic processes, body odor, and health.

Airborne fine particulate matter (PM2.5) pollution is known to have adverse effects on human health, and owing to their carcinogenic and mutagenic nature, polycyclic aromatic hydrocarbons (PAHs) are of particular concern. This study investigated the effect of ultraviolet (UV)-induced photocatalysis on the degradation of PAHs in PM2.5, employing titanium dioxide (TiO2)-supporting quartz fibre filters. A TiO2 layer was formed on the quartz fibre filters, and airborne PM2.5 was collected using an air sample at a flow rate of 500 L/min for 24 h. The PM2.5 samples were subsequently irradiated with ultraviolet rays at 1.1 mW/cm2. The amounts of nine targeted PAHs (phenanthrene, PHE, anthracene, ANT, pyrene, PYR, benzo[a]anthracene, BaA, chrysene, CHR, benzo[b]fluoranthene, BbF, benzo[k]fluoranthene, BkF, benzo[a]pyrene, BaP, and benzo[g,h,i]perylene, BgP) gradually decreased during the treatment, with half-lives ranging from 18 h (PHE) to 3 h (BaP), and a significantly greater reduction was found in comparison with the PAHs collected in the control (non-TiO2 coated) quartz fibre filters. However, the degradation rates were much faster when the PAHs were in direct contact with the TiO2 layer. As PM2.5 is a mixture of various kinds of solids, co-existing components can be a rate-determining factor in the UV-induced degradation of PAHs. This was demonstrated by a remarkable increase in degradation rates following the removal of co-existing salts from the PM2.5 using water treatment.

Diallyl disulfide (DADS) and allyl methyl sulfide (AMS) have been known as a metabolic product of sulfur-containing foods, typically garlic. The odour of such organosulfur compounds following garlic ingestion is often considered as an unpleasant element. Although previous studies have identified the DADS and AMS associated with garlic breath, no study has been reported on the determination of both compounds emanating from human skin surface. This study aimed to demonstrate the effect of garlic ingestion on the dermal emissions of DADS and AMS using a passive flux sampler coupled with gas chromatography-mass spectrometry. Firstly, baseline levels were investigated for 30 healthy volunteers in their daily life. The results of 1 h-sampling at the forearm showed the emission fluxes of both compounds followed the lognormal distribution with a geometric mean of 0.18 ng cm−2 h−1 for DADS and 0.22 ng cm−2 h−1 for AMS. Subsequently, the garlic ingestion tests were conducted for selected volunteers. The emission flux of DADS increased just after grilled garlic ingestion and decreased gradually thereafter. In contrast, the dermal emission flux of AMS reached a peak at 30 min after ingestion, and then gradually decreased. This peak shift suggests AMS is relatively latent in the skin organs.

Carbonaceous constituents in fine particulate matter (PM2.5) are often associated with adverse health effects in humans. Although air filtration technology is widely used for preventing exp...

Background: Human skin gas is known as traces of gas emanating from the human skin. Exogenous chemicals such as toluene may be released from the skin surface when absorbed into the body. However, dermal emission of toluene has not been fully determined in relation to inhalation exposure. Objectives: This study aimed to characterise the mechanism of toluene emanating from the skin surface of healthy volunteers in relation to inhalation exposure. Methods: Dermal emission flux of toluene was determined in healthy volunteers employing a passive flux sampler and gas chromatography-mass spectrometry. Results: The dermal emission of toluene occurs when toluene is absorbed by inhalation. The half-life obtained from the decrease in the dermal emission flux suggested the time-course of the dermal emission corresponds to that of the blood concentration. The whole-body emission rate of toluene was estimated to be 9.9% of the uptake rate by inhalation exposure. This suggests the toluene is excreted approximately 80% through urine, 7% - 14% by exhaled air, and 10% from the skin surface. Conclusions: This demonstrates that dermal emission is a newly discovered route of excretion of toluene from the human body and that dermal toluene might indicate the individual biological susceptibility to inhalation exposure to toluene.

Airborne transmission is one of the routes for the spread of COVID-19 which is caused by inhalation of smaller droplets1 containing SARS-CoV-2 (i.e., either virus-laden particulate matter: PM and/or droplet nuclei) in an indoor environment. Notably, a significant fraction of the small droplets, along with respiratory droplets, is produced by both symptomatic and asymptomatic individuals during expiratory events such as breathing, sneezing, coughing and speaking. When these small droplets are exposed to the ambient environment, they may interact with PM and may remain suspended in the atmosphere even for several hours. Therefore, it is important to know the fate of these droplets and processes (e.g., physical and chemical) in the atmosphere to better understand airborne transmission. Therefore, we reviewed existing literature focussed on the transmission of SARS-CoV-2 in the spread of COVID-19 and present an environmental perspective on why airborne transmission hasn't been very conclusive so far. In addition, we discuss various environmental factors (e.g., temperature, humidity, etc.) and sampling difficulties, which affect the conclusions of the studies focussed on airborne transmission. One of the reasons for reduced emphasis on airborne transmission could be that the smaller droplets have less number of viruses as compared to larger droplets. Further, smaller droplets can evaporate faster, exposing SARS-CoV-2 within the small droplets to the environment, whose viability may further reduce. For example, these small droplets containing SARS-CoV-2 might also physically combine with or attach to pre-existing PM so that their behaviour and fate may be governed by PM composition. Thus, the measurement of their infectivity and viability is highly uncertain due to a lack of robust sampling system to separately collect virions in the atmosphere. We believe that the present review will help to minimize the gap in our understanding of the current pandemic and develop a robust epidemiological method for mortality assessment., Graphical abstract Schematic diagram showing interaction of droplet nuclei with particulate matter, radiation and oxidants in the atmosphere. POA and WSOA are primary organic aerosol and water-soluble organic aerosols components of the particulate matter. Unlabelled Image

Ammonia is one of the members of odor gases and a possible source of odor in indoor environment. However, little has been known on the actual emission rate of ammonia from the human skin surface. Then, this study aimed to estimate the whole-body dermal emission rate of ammonia by simultaneous and multi-point measurement of emission fluxes of ammonia employing a passive flux sampler - ion chromatography system. Firstly, the emission fluxes of ammonia were non-invasively measured for ten volunteers at 13 sampling positions set in 13 anatomical regions classified by Kurazumi et al. The measured emission fluxes were then converted to partial emission rates using the surface body areas estimated by weights and heights of volunteers and partial rates of 13 body regions. Subsequent summation of the partial emission rates provided the whole body dermal emission rate of ammonia. The results ranged from 2.9 to 12mgh-1 with an average of 5.9±3.2mgh-1 per person for the ten healthy young volunteers. The values were much greater than those from human breath, and thus the dermal emission of ammonia was found more significant odor source than the breath exhalation in indoor environment.

OBJECTIVES: Volatile organic compounds (i.e., VOCs) emanating from the human skin are used to detect disease biomarkers and causes of body odour. Seven-day intake of New Zealand blackcurrant (NZBC) powder reduced skin emission of 2-nonenal, a lipid peroxidation compound responsible for body odour in older adults. Anthocyanin-induced bioavailability of plasma metabolites by intake of NZBC may affect the production of VOCs. In the present study, we examined the effect of 7-day NZBC powder intake on the skin emission of 76 VOCs. METHODS: Fourteen Caucasian adults (9 males, age: 55 ± 5 yr) volunteered. Participants consumed NZBC powder for 7 days (Sujon Berries, NZ, 6 g·day(-1) with 138.6 mg anthocyanin, 49 mg Vit C, 5.2 g of carbohydrates and total phenolic content of 271.6 mg per serving). Two hours after the last intake, a passive flux sampler with trapping media (MonoTrap®, DCC18, GL Science, Japan) was applied to the skin in the base of the neck for one hour, and gas chromatography-mass spectrometry was used for media analysis (Kimura et al., 2016). Participants did not use hot water or soap for 48 hrs on the skin sampling location. Dietary anthocyanin intake was quantified using a food frequency questionnaire. Data were analysed with paired, two-tailed t-test and effect size (Cohen's d) was calculated. RESULTS: Decreases in skin emission were observed for acetic acid (−57%, P = 0.006, d = −1.26), 2-hexanone (−47%, P = 0.031, d = −0.86), 6-methyl-5-hepten-2-one (−93%, P = 0.005, d = −1.23), benzaldehyde (−86%, P = 0.004, d = −0.96), allyl methyl sulfide (−35%, P = 0.015, d = −0.98) and increases for γ-octanolactone (+65%, P = 0.023, d = 0.98) and γ-decanolactone (+47%, P = 0.015, d = 1.11). For these VOCs, there was no significant correlation between daily anthocyanin intake and baseline values. A trend for a decrease was observed for isovaleraldehyde, hexanal and 2-pentanone and an increase for heptanoic acid and γ-nonanolactone, all 0.05

Air pollution by fine particulate matter, PM2.5 has been inviting considerable concerns in East Asia. This study then aimed to characterize PM2.5 and its water-soluble ions collected at Shibuya, central Tokyo, Japan from July 2013 to May 2015, in order to better understand the air pollution mechanism and potential sources of PM2.5 of the city. Analytical results showed the PM2.5 was a mixture of aggregates of formless particles and its concentration ranged from 5.4 to 39μg/m3, with a mean of 14 ± 6.7μg/m3 (n=46). SO42- and NH4+ were abundant in PM2.5 and their presence mostly determined the variation of PM2.5 level. High concentration episodes were found in the season when air masses came from Asian continent, and a long-range transport of urban aerosols and soil-derived particles was suggested by changes in the chemical compositions.

Cigarette smoking is a significant risk factor for higher incidences of numerous adverse health consequences. Related health disorders are also found in non-smokers exposed to secondhand smoke (SHS). To investigate the influence of cigarette smoking and exposure to SHS on the composition of human skin gas, a trace biogas emanating from human skin, dermal emissions of volatile compounds were semi-quantitatively measured for volunteers who smoke a cigarette and those exposed to SHS. This was performed using a passive flux sampler (PFS) coupled with gas chromatography mass spectrometry (GCMS). Numerous chemicals were detected, including acetaldehyde, toluene, 3-methyl furan (3-MF), 2,5-dimethyl furan (2,5-DMF), 3-ethenyl pyridine (3-EP), and nicotine, in the samples collected from the smokers after a smoking event, and a remarkable increase in the amount of chemicals collected was observed just after smoking. These chemicals were also found in the samples collected from volunteers exposed to SHS. Assessment of current smoking status is important for managing the negative effects of active and passive smoking, and for the development of public health policy. The tobacco specific chemicals such as 3-MF, 2,5-DMF, 3-EP, and nicotine, emanating from human skin surfaces, represent a potential non-invasive biomarker for monitoring current smoking status of active and passive smokers after establishing a more quantitative procedure.

Zinc oxide nanoparticles as a nanophotocatalyst has great potential for self-cleaning applications in concrete structures, its effects on the cement hydration, setting time and compressive strength are also important when using it in practice. This paper reports the effects of zinc oxide nanoparticles, as an additive material, on properties of cement-based materials. Setting time, compressive strength and porosity of mortars were investigated. Microstructure and morphology of pastes were characterized using scanning electron microscope and X-ray diffraction (XRD), respectively. Moreover, thermal gravimetric analysis (TGA) and Fourier-transform infrared spectrometer (FTIR) were also used to determine the hydration reaction. The results show that Portland cement paste with additional ZnO was found to slightly increase the water requirement while the setting time presented prolongation period than the control mix. However, compressive strength of ZnO mixes was found to be higher than that of PC mix up to 15% (at 28 days) via filler effect. Microstructure, XRD and TGA results of ZnO pastes show less hydration products before 28 days but similar at 28 days. In addition, FTIR results confirmed the retardation when ZnO was partially added in Portland cement pastes.

The influence of pH and pH adjustment conditions on the photocatalytic oxidation of aqueous ammonia in the presence of Pt-TiO 2 under airflow was investigated as a possible treatment for ammonia-containing wastewater. Ammonia oxidation proceeded only under alkaline conditions, and the maximum initial oxidation rate was obtained at pH ∼ 10. The pH of the reaction suspension decreased with the formation of nitrite and nitrate species, stopping completely when the pH fell below 7 for reactions in which the initial pH (pH i ) was adjusted within the range 8.7–11.3 using NaOH(aq). The rate of ammonia oxidation was higher when NaOH(aq) was used to adjust the pH i than that achieved using Na 2 CO 3 –NaHCO 3 buffer solution at the same pH. The maximum ammonia adsorption on Pt-TiO 2 (measured under dark conditions) was obtained at pH 10 and the amount of ammonia adsorbed when the pH i was adjusted with NaOH(aq) was higher than that achieved using the Na 2 CO 3 –NaHCO 3 buffer solution at the same pH; thus, the amount of adsorbed ammonia strongly affected the oxidation rate. Although the selectivity for the sum of the undesired products, nitrite and nitrate was high when the ammonia concentration was low (e.g., 5 mM), the selectivity decreased as the initial ammonia concentration increased for each pH and pH adjustment condition. Suppression of the selectivity was evident when the pH i was adjusted to 10 with NaOH(aq). The selectivity was affected by the changes in the density of N-containing species on the photocatalyst surface as the pH and pH adjustment conditions were varied.

Although clean air is one of the most important necessities for human life and health, the risk of natural disasters causing air pollution that reduces or inhibits “resiliency” of the victims and communities has not been well understood. This chapter examines the secondary disaster of the air pollution events induced by the Great East Japan Earthquake and subsequent tsunami in 2011—such as the release and diffusion of radioactive substances from the severely damaged Fukushima Daiichi nuclear power plant, chemical contamination in indoor air of temporary housing built (so-called Sick House Syndrome), and the scattering of asbestos fibers liberated by the quake and tsunami. Air pollution is something that often cannot be seen until severe impacts are noticed later. The paper then describes the importance of air quality monitoring by scientific means and sharing knowledge for risk recognition and immediate pollution controls based on the identification of source of problems for risk reduction, in the context of resilience.

The oxidation of aqueous ammonia over a platinum-loaded TiO2 photocatalyst was investigated for purification of wastewater. The reaction rate for the decomposition of aqueous ammonia was significantly increased by the addition of oxygen to the reaction system. The enhancement of charge separation efficiency due to consumption of photogenerated electrons by oxygen increased the decomposition rate. For dissolved oxygen (DO) concentrations below 0.09 mM, the initial decomposition rate and the selectivity for nitrite and nitrate increased as DO concentration increased. Although the selectivity for nitrite and nitrate was over 90% for the initial concentration of ammonia ([NH3]i) = 5.0 mM under an air flow, the selectivity was suppressed as the initial concentration of ammonia was increased, e.g., 43% for [NH3]i = 100 mM.

F ig .1 Schemat ic v iew of the process ing un i t (p rototype) emp loy ing MnO2 honeycomb f i l te r fo r the ox idat ive decompos i t ion o f fo rma ldehyde gas , used in th is study Fig.5 Effect of initial concentration of evaporated formaldehyde gas on the time courses of air concentrations of formaldehyde (left) and carbon dioxide (right) during the operation of the processing unit employing MnO2 filter in the full-scale chamber (Experiment cases of 4 and 5, 6, 7, temperature: 25 °C, RH: 50 %) 0.01 0.1 1 10 10

It is commonly said elderly persons have a characteristic body odor, and, at present, two chemical compounds have been found to vary with age in male Japanese: 2-nonenal and diacetyl. To investigate dermal emission flux of the ageing odor related compounds, we have developed a non-invasive sampling device based on a concept of passive flux sampler (PFS). The sampler was placed on the skin surface to create a headspace, and the gases emanating from skin moved toward a disk-type adsorbent. The trapped gases were then extracted with dichloromethane and determined by GCMS. The PFS was practically applied to healthy volunteers covering a wide range of age. Since emission fluxes of both compounds remarkably varied with sampling position, the nape of the neck was fixed as regular sampling position where there are dense networks of both sebaceous and eccrine glands which are potential sources of both compounds. The emission flux of 2-nonenal increased with age for both male and female volunteers, whilst the flux of diacetyl showed highest in 30s and decreased over 40s. Although diacetyl has been known as a middle-aged male odor, this study showed the odor caused by diacetyl was not specific to male.

A simple monitoring system of indoor air pollution is proposed by integrating a novel colorimetric detector of formaldehyde (HCHO) and a function of a built-in camera on mobile phone. The colorimetric detector employs a solid phase colorimetric reagent made from 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, ZnO, KIO4 and agar, and changes colour from white to purple by exposure to HCHO gas. The degree of colour changes expressed in Red, Green and Blue model model responded to the HCHO concentration levels both in air and from building materials. Limit of quantitation of the detector with 24 h-exposure resulted in 0.011 mg/m(3) of air concentration which meets a requirement of methodology to detect indoor air quality guideline level of HCHO set by World Health Organization. The detector is also applicable to classify HCHO-emitting materials at least into Type 1, whose emission flux is greater than 120 μg/m(2)/h, and others. Then, variation of the acquired photo images was investigated by using various mobile phones and changing conditions of photography. As a result, the calibration of the measured colour intensity with a colour standard reduced the variation of the results and gave a significant output when the auto-focused images were taken under the condition of common indoor environment.

We prepared NaTaO3 by hydrothermal method and solvothermal method. Na2Ta2O6 was obtained by hydrothermal treatment of water soluble tantalum complex and NaOH. On the other hand NaTaO3 was obtained by solvothermal treatment of TaCl5 and NaOH in methanol. Many samples were synthesized in various hydrothermal condition, however all samples were Na2Ta2O6 or amorphous. Primary particle size of samples obtained by solvothermal method was 10 nm. Primary particles aggregated and formed 20-50 nm secondly particles. Moreover, specific surface area of NaTaO3 synthesized by the solvothermal method was 109 m2/g. Therefore we succeeded in obtaining NaTaO3 fine particles with high specific surface area. NaTaO3 sample loaded NiO of 6 wt% produced H2 of 600 μmol/h. When solvothermal treatment time was extended from 5 hours to 10 hours and stirring in solvothermal treatment, water splitting activity of NaTaO3 was improved.

A new solution method that can be used to synthesize borate compounds was developed using citric acid and ethylenediamine. The conventional polymerizable complex method (polyester method) has a significant advantage in terms of homogeneity of the precursor, and it has been utilized in the synthesis of numerous oxide ceramics. However, it is very difficult to synthesize borate compounds by the conventional polymerizable complex method because boron reacts with the glycol that is necessary for the polymerization as polyester and is volatilized from the solution. In this paper, functional borate compounds such as YBO3:Eu3+, InBO3, and K3Ta3B2O12 were synthesized by the conventional polyester-type polymerizable complex method as well as the new solution method. In the polyester method, citric acid was dissolved in propylene glycol and the component metal salts were then dissolved in this solution. In the method that we propose in this paper, citric acid and ethylenediamine were dissolved in distilled water, and component metal salts were added to the solution. All solutions were heated at 403 K with stirring for the polymerization reaction to proceed, yielding polymer resins. The resins were heated to 723 K and powder precursors were obtained. The precursors were calcinated under various temperature conditions. In the case of YBO3:Eu3+, the formed product was Y2O3 by the polyester method due to volatilization of boron. On the other hand, single-phase YBO3:Eu3+ was synthesized by the new method. YBO3:Eu3+ synthesized by the method showed higher photoluminescence intensity than samples synthesized by a solid-state reaction method and the complex gelation method. Synthesis of single phase InBO3 and K3Ta3B2O12 was also successfully demonstrated by the method using a very small excess amount of H3BO3.

Secondary emission products generated through chemical reactions become a recent concern in relation to indoor air quality. We have focused on formic acid (HCOOH) whose generation mechanism in indoor air has been unknown. In this study, we examined influence of oxidant on the indoor air concentrations of HCOOH and emission process of HCOOH by both laboratory experiments and field measurements. Firstly, emission fluxes of HCHO and HCOOH from plywood were determined using a small bowl-type stainless chamber. The emission flux of HCOOH increased with those of HCHO under ambient air containing oxidant. While the oxidant was removed in the chamber, HCOOH significantly emitted with NO2 at the chamber outlet. We then concluded HCOOH is a product of the gas phase reaction between HCHO, NO2 and O3. Field measurements conducted at a newly-build detached house supported the conclusion as that indoor concentrations of HCOOH increased with an increase in concentrations of the oxidant introduced from outdoor by air ventilation.