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Graphical abstract Abstract Intake of a variety of vegetables and fruit is found to be effective in promoting health; one of the reasons for this is activation of nuclear factor erythroid 2-related factor 2 (Nrf2), a basic leucine zipper protein. Nrf2 is activated by chemical modification of Kelch-like ECH-associated protein 1 (Keap1), a negative regulator for this transcription factor, and specific phosphorylation of Nrf2, resulting in upregulation of its downstream gene products for antioxidant proteins, phase-II xenobiotic-metabolizing enzymes, and phase-III transporters. This type of activation plays a role in adaptive response and protection against oxidative and electrophilic stress. Multiple phytochemicals, such as curcumin, sulforaphane, and (E)-2-alkenals, have been identified as Nrf2 activators and may reduce the adverse health effects of oxidants and electrophiles. In this review, we introduce plant components that are known as Nrf2 activators and associated phytochemical-mediated reduction of risk from chemicals which cause oxidative and electrophilic stress. We also discuss the capture and inactivation of methylmercury, an electrophile, by sulfane sulfur atoms contained in garlic.

Prion diseases are fatal neurodegenerative disorders caused by deposition of scrapie prion protein aggregates (PrPSc) in the brain. We previously reported that styrylchromone (SC) and benzofuran (BF) derivatives have potential as imaging probes for PrPSc. To further improve their properties, we designed and synthesized 2-(benzofuran-2-yl)-chromone (BFC) derivatives hybridized with SC and BF backbones as novel single-photon emission computed tomography probes for the detection of cerebral PrPSc deposits. Recombinant mouse prion protein (rMoPrP) aggregates and mouse-adapted bovine spongiform encephalopathy (mBSE)-infected mice were used to evaluate the binding properties of BFC derivatives to PrPSc. The BFC derivatives exhibited high binding affinities (equilibrium dissociation constant [Kd] = 22.6–47.7 nM) for rMoPrP aggregates. All BFC derivatives showed remarkable selectivity against amyloid beta aggregates. Fluorescence microscopy confirmed that the fluorescence signals of the BFC derivatives corresponded to the antibody-positive deposits of PrPSc in mBSE-infected mouse brains. Among the BFC derivatives, [125I]BFC-OMe and [125I]BFC-NH2 exhibited high brain uptake and favorable washout from the mouse brain. In vitro autoradiography demonstrated that the distribution of [125I]BFC-OMe in the brain tissues of mBSE-infected mice was co-localized with PrPSc deposits. Taken together, BFC derivatives appear to be promising prion imaging probes., ACS Infectious Diseases, 8(9), pp. 1869-1882; 2022

1-Nitropyrene (1-NP) is a major nitro-polycyclic aromatic hydrocarbon (nitro-PAH), and a common constituent in diesel exhaust particles (DEPs). Absorbed 1-nitropyrene is partly metabolized to 1-aminopyrene and excreted in urine. Recently, the number of diesel cars has been increasing, which could be a major cause of air pollution, resulting elevated levels of traffic-related DEPs around cities. The aim of this study was to investigate the usability of 1-aminopyrene (1-AP) as a biomarker for DEP exposure by examining the association between urinary 1-AP concentration and the amount of exposure to atmospheric 1-NP. The study subjects included 65 individuals who work on vehicular roads or bus terminals. Their 24 h urine samples were collected, and atmospheric air was sampled using a personal air sampler for 24 h. Urinary 1-AP and atmospheric nitro-PAH levels were measured using a high-pressure liquid chromatography-fluorescence detector (HPLC-FD). The average urine 1-AP concentration was 0.334 pg/g creatinine. Urinary 1-AP levels were significantly correlated with 1-NP level exposure (r = 0.385, p = 0.002) but not with the other nitro-PAHs. When the subjects were classified into high-and low-exposure groups, a significant association was only found in the high exposure group (r = 0.357, p = 0.045). In conclusion, there was a significant correlation between 1-NP exposure and urinary 1-AP concentration; therefore, urinary 1-AP level could be used as an exposure biomarker for DEP. Supplementary Information The online version contains supplementary material available at 10.1007/s43188-021-00096-z.

As a background sampling site in western Japan, the Kanazawa University Wajima Air Monitoring Station (KUWAMS) continuously observes the air pollutants, including PM1, PM2.5, organic carbon (OC) and element carbon (EC). Data for September 2019 to April 2020 were compared with data for September 2018 to April 2019. The mean concentrations of both PM1 and PM2.5 were 4.10 µg/m3 (47%) and 5.82 µg/m3 (33%) lower, respectively in the Coronavirus Disease 2019 (COVID-19) period (January to April) than in the same period in 2019. Notably, the average concentrations of both classes of particulate matter (PM) in the COVID-19 period were the lowest for that period in all years since 2016. OC and EC also considerably lower (by 69 and 63%, respectively) during the COVID-19 period than during the same period in 2019. All pollutants were then started to increase after the resumption of the work in 2020. The pollutant variations correspond to the measure implemented during the COVID-19 period, including the nationwide lockdown and work resumption. Furthermore, the reductions in the ratios PM1/PM2.5 and OC/EC during COVID-19 period indicate lighter pollution and fewer emission sources. This analysis of the changes in the pollutant concentrations during the epidemic and non-epidemic periods illustrates the significance of the dominant pollution emissions at KUWAMS and the impact of pollution from China that undergoes long-range transport to KUWAMS.

Prion diseases are fatal neurodegenerative diseases characterized by the deposition of abnormal prion protein aggregates (PrPSc) in the brain. In this study, we developed hydroxyethylamino-substituted styrylchromone (SC) and 2-(2-(pyridin-3-yl)vinyl)-4H-chromen-4-one (VPC) derivatives for single-photon emission computed tomography (SPECT) imaging of PrPSc deposits in the brain. The binding affinity of these compounds was evaluated using recombinant mouse prion protein (rMoPrP) aggregates, which resulted in the inhibition constant (Ki) value of 61.5 and 88.0 nM for hydroxyethyl derivative, (E)-2-(4-((2-hydroxyethyl)amino)styryl)-6-iodo-4H-chromen-4-one (SC-NHEtOH) and (E)-2-(4-((2-hydroxyethyl)(methyl)amino)styryl)-6-iodo-4H-chromen-4-one (SC-NMeEtOH), respectively. However, none of the VPC derivatives showed binding affinity for the rMoPrP aggregates. Fluorescent imaging demonstrated that the accumulation pattern of SC-NHEtOH matched with the presence of PrPSc in the brain slices from mouse-adapted bovine spongiform encephalopathy-infected mice. A biodistribution study of normal mice indicated low initial brain uptake of [125I]SC-NHEtOH (0.88% injected dose/g (% ID/g) at 2 min) despite favorable washout from the brain (0.26% ID/g, at 180 min) was displayed. [125I]SC-NHEtOH exhibited binding affinities to both artificial prion aggregates as well as prion deposits in the brain. However, significant improvement in the binding affinity for PrPSc and blood–brain barrier permeability is necessary for the development of successful in vivo imaging probes for the detection of cerebral PrPSc in the brain., Chemical and Pharmaceutical Bulletin, 70(3), pp. 211-219; 2022

Particulate polycyclic aromatic hydrocarbons (PAHs) were continuously observed at Kanazawa University Wajima Air Monitoring Station (KUWAMS), a background site located in western Japan and downwind of mainland China that is constantly under the influence of polluted air masses originating from China The observations showed that the concentration of particulate PAHs at KUWAMS sharply dropped to the lowest level (62 pg m–3) of the cold season in the last 5 years after the implementation of COVID-19 control measures in China Despite the occasional dilution with clean air, the decrease in PAHs at KUWAMS reflected the reduction in emission intensity in China Moreover, the PAH concentrations at KUWAMS in February, March, and April of 2020 compared with the same period in the previous year decreased by 52 6%, 36 6%, and 36 7%, respectively These changes were consistent with the decline in SO2 and NO2 in northern China, which intensified during the control of COVID-19 and was slightly moderated after the resumption of work In addition, there was little change in the composition of PAHs at KUWAMS before and during the COVID-19 outbreak and compared with previous years, which suggests a stable source composition These findings emphasize the importance of decreased emission intensity in China for reducing long-range transport of PAHs and pollution levels in downwind areas © The Author(s)

PM2.1 was collected at urban and suburban elementary schools in Shanghai during two sampling periods in cold and warm seasons in 2007. Nine polycyclic aromatic hydrocarbons (PAHs) and ten nitro-polycyclic aromatic hydrocarbons (NPAHs) in PM2.1 were determined. During both seasons, the concentrations of PAHs and NPAHs at urban and suburban schools were not significantly different (p>0.05) and were higher in the cold period than in the warm period. According to the diagnostic ratios, PAHs and NPAHs at both schools were subject to the mixed effects of vehicle emission and coal combustion during both periods. Moreover, the results of the backward trajectory showed that PAHs and NPAHs were more susceptible to external polluted air masses in the cold period. At both urban and suburban schools, the inhalation cancer risk of PAHs and NPAHs in PM2.1 for children during elementary period was dozens of times of the acceptable risk level regulated by the U.S.EPA, highlighting the adverse impact of exposure to PAHs and NPAHs on the healthy development of children.

To study the toxicity of 3-hydroxybenzo[c]phenanthrene (3-OHBcP), a metabolite of benzo[c]phenanthrene (BcP), first we compared it with its parent compound, BcP, using an in ovo-nanoinjection method in Japanese medaka. Second, we examined the influence of 3-OHBcP on bone metabolism using goldfish. Third, the detailed mechanism of 3-OHBcP on bone metabolism was investigated using zebrafish and goldfish. The LC

SVS-1 is a cationic amphiphilic peptide (CAP) that exhibits a preferential cytotoxicity towards cancer cells over normal cells. In this study, we developed radiogallium-labeled SVS-1 (67Ga-NOTA-KV6), as well as two SVS-1 derivatives, with the repeating KV residues replaced by RV or HV (67Ga-NOTA-RV6 and 67Ga-NOTA-HV6). All three peptides showed high accumulation in epidermoid carcinoma KB cells (53–143% uptake/mg protein). Though 67Ga-NOTA-RV6 showed the highest uptake among the three CAPs, its uptake in 3T3-L1 fibroblasts was just as high, indicating a low selectivity. In contrast, the uptake of 67Ga-NOTA-KV6 and 67Ga-NOTA-HV6 into 3T3-L1 cells was significantly lower than that in KB cells. An endocytosis inhibition study suggested that the three 67Ga-NOTA-CAPs follow distinct pathways for internalization. In the biodistribution study, the tumor uptakes were found to be 4.46%, 4.76%, and 3.18% injected dose/g of tissue (% ID/g) for 67Ga-NOTA-KV6, 67Ga-NOTA-RV6, and 67Ga-NOTA-HV6, respectively, 30 min after administration. Though the radioactivity of these peptides in tumor tissue decreased gradually, 67Ga-NOTA-KV6, 67Ga-NOTA-RV6, and 67Ga-NOTA-HV6 reached high tumor/blood ratios (7.7, 8.0, and 3.8, respectively) and tumor/muscle ratios (5.0, 3.3, and 4.0, respectively) 120 min after administration. 67Ga-NOTA-HV6 showed a lower tumor uptake than the two other tracers, but it exhibited very low levels of uptake into peripheral organs. Overall, the replacement of lysine in SVS-1 with other basic amino acids significantly influenced its binding and internalization into cancer cells, as well as its in vivo pharmacokinetic profile. The high accessibility of these peptides to tumors and their ability to target the surface membranes of cancer cells make radiolabeled CAPs excellent candidates for use in tumor theranostics., Cancers, 13(10), art. no. 2388; 2021

Snow layers, L-I to -III, collected from the wall of a snow pit at Murododaira on Mt. Tateyama, Japan, were melted and filtered into soluble (S) and particulate (P) fractions by a glass filter (pore size: 0.5 µm). The total concentration of the polycyclic aromatic hydrocarbons (PAHs) was highest in L-I. In this layer, PAHs with 5–6 rings, which exist mainly in particulate matter (PM) in the atmosphere, were almost completely in the P-fraction. PAHs with 4 rings, which exist in both the particle and the gas phase in the atmosphere, exhibited higher or equal concentrations in the S-fraction. Finally, non-sea salt SO42−, which exists as sulfur oxides in the atmosphere, was filtered into the S-fraction. The air mass for L-I, traced via back trajectory, passed through northeastern and central China. These results suggest that PAHs transported from China to Japan precipitated in snow at Mt. Tateyama. In the melted snow, PM-associated PAHs were primarily in the P-fraction, but lower molecular-weight PAHs were partly in the S-fraction. Gas-phase PAHs were also found in the S-fraction. Furthermore, the high concentration of non-sea salt Ca2+ in the S-fraction of L-I implies the presence of Asian Dust.

Fine particulate matter (PM2.5) samples were collected in the summer and winter of 2015 and 2017 in Xinxiang, China. Nine polycyclic aromatic hydrocarbons (PAHs) and three nitro-PAHs (NPAHs) in PM2.5 were detected via high-performance liquid chromatography (HPLC). The PAHs concentration in summer and winter decreased from 6.37 ± 1.30 ng/m3 and 96.9 ± 69.9 ng/m3 to 4.89 ± 2.67 ng/m3 and 49.8 ± 43.4 ng/m3 from 2015 to 2017. NPAHs decreased in winter (from 1707 ± 708 pg/m3 to 1192 ± 1113 pg/m3), but increased in summer from 2015 (336 ± 77.2 pg/m3) to 2017 (456 ± 312 pg/m3). Diagnostic ratios of PAHs indicated that petroleum combustion was the main emission source in summer, and pollutants originating from the combustion of petroleum, coal and biomass dominated in winter. The 2-nitrofluoranthene (2-NFR)/2-nitropyrene (2-NP) ratio in this study demonstrated that the OH radical pathway was the main pathway for the formation of 2-NP and 2-NFR. The mean total benzo[a]pyrene-equivalent concentrations (BaPeq) and incremental lifetime cancer risk (ILCR) values decreased from 2013 to 2017. The high value of total BaPeq in the winter of 2017 in Xinxiang revealed that a high-risk of cancer remained for residents. The results of this study demonstrate that the decreases in PAHs and NPAHS concentrations from 2015 to 2017. Combined with reducing gaseous pollutants concentration, the reduction in this study might be attributable to emissions reductions by implementing the air pollution control regulations in Xinxiang city in 2016.

Polycyclic aromatic hydrocarbons (PAHs) are a class of important organic pollutants widely emitted from anthropogenic activities, with a general distribution in the gas and particulate phases. Some PAHs are carcinogenic, teratogenic, and mutagenic. Inhalation exposure to PAHs is correlated with adverse health outcomes in the respiratory and cardiovascular systems. Thus, it is significant to determine the exposure level of the general population. This study summarizes the evaluation methods for PAH exposure, focusing on different exposure parameters. External exposure can be determined via the collection of the environmental pollution concentration through active samplers or passive samplers during environmental monitoring or personal sampling. Time-activity patterns give critical exposure information that captures the exposure period, origin, and behaviors. Modeling is a labor-less approach for human exposure estimation, and microenvironmental exposure requires specific research. It is important to select appropriate methods to quantify the exposure level to provide accurate data to establish the exposure–risk relationship and make scientific suggestions for the protection of public health.

Kirishima is a typical Japanese commercial city, famous for frequent volcanic activity. This is the first study to determine the characteristics of PM2.5-bound polycyclic and nitro-polycyclic aromatic hydrocarbons (PAHs and NPAHs) and water-soluble inorganic ions (WSIIs) in this city. In this study, the non-volcanic eruption period was taken as the target and daily PM2.5 samples were collected from 24 November to 21 December 2016. The daily concentrations in PM2.5 of ƩPAHs, ƩNPAHs, and ƩWSIIs ranged from 0.36 to 2.90 ng/m3, 2.12 to 22.3 pg/m3, and 1.96 to 11.4 &mu, g/m3, respectively. Through the results of the diagnostic ratio analyses of the PAHs, NPAHs, and WSIIs and the backward trajectory analysis of the air masses arriving in Kirishima, the emission sources of PAHs, NPAHs, and WSIIs in PM2.5 in Kirishima were influenced by the coal burning that came from the East Asian continent, although there was no influence from volcanic emission sources during the sampling period. The total benzo[a]pyrene (BaP)-equivalent concentration was lower than many other cities but the health risks in Kirishima were nonetheless notable. These findings are very important for future research on PM samples during the inactive Asian monsoon and volcanic eruption periods, to further understand the characteristics of air pollutants in Kirishima, and to contribute to the improvement in health of residents and a reduction in the atmospheric circulation of air pollutants in East Asia.

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) in PM2.5 were first observed at a background site (Yuzhong site: YZ site) in the northwestern highlands of China in five seasonal campaigns. Compared with major northwestern cities, PAHs and NPAHs at the YZ site were at a lower level but showed consistent seasonal differences. The PAH and NPAH concentrations peaked in the winter campaigns, which were 36.11 ± 6.54 ng/m3 and 418.11 ± 123.55 pg/m3, respectively, in winter campaign 1 and 28.97 ± 10.07 ng/m3 and 226.89 ± 133.54 pg/m3, respectively, in winter campaign 2. These values were approximately a dozen times larger those in other campaigns. The diagnostic ratios indicate that vehicle emissions were the primary source of the PAHs throughout the five campaigns, and coal and biomass combustion also contributed during the winter, summer, and fall campaigns. Among NPAHs, 2-nitrofluoranthene and 2-nitropyrene were generated through OH radical-initiated reactions during atmospheric transport, while 1-nitropyrene came from combustion sources. There is an observation worth pondering, which is that the ratio between pyrene and fluoranthene increased abnormally in the spring and fall campaigns, which is presumably caused by the burning of Tibetan barley straw in the northwestern highlands. The backward trajectories over Tibetan areas in Qinghai and southwestern Gansu are consistent with this hypothesis. In addition, this study reported for the first time that the burning of Tibetan barley straw has become a seasonal contributor to air pollution in northwestern China and is participating in the atmospheric transport of air pollutants driven by the monsoon in East Asia, which urgently requires further research.

Daily PM2.5 (particulate matter with aerodynamic diameter &le, 2.5 &mu, m) samples were simultaneously collected at two background sites (Wajima Air Monitoring Station (WAMS) and Fukue-Jima Atmosphere and Aerosol Monitoring Station (FAMS)) in Japan in the East Asian winter and summer monsoon periods of 2017 and 2019, to compare the characteristics of air pollutants among different regions and to determine the possible variation during the long-range transport process. Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and water-soluble inorganic ions (WSIIs) were analyzed. Despite the PM2.5 concentrations at FAMS (8.90 &ndash, 78.5 &micro, g/m3) being higher than those at WAMS (2.33 &ndash, 21.2 &micro, g/m3) in the winter monsoon period, the average concentrations of &sum, PAHs, &sum, NPAHs, and &sum, WSIIs were similar between the two sites. Diagnostic ratios indicated PAHs mainly originated from traffic emissions and mostly aged, whereas NPAHs were mostly secondarily formed during long-range transport. WSIIs at WAMS were mainly formed via the combustion process and secondary reactions, whereas those at FAMS mainly originated from sea salt and dust. Backward trajectories revealed the air masses could not only come from Asian continental coastal regions but also distant landlocked areas in the winter monsoon period, whereas most came from the ocean in the summer monsoon period. These findings can provide basic data for the establishment of prediction models of transboundary air pollutants in East Asia.

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) in PM2.5 samples were collected at a roadside monitoring station in Kanazawa, Japan, in every season from 2017 to 2018. Nine PAHs and five NPAHs were determined using high-performance liquid chromatography with fluorescence detection and chemiluminescence detection, respectively. The mean concentrations of PAHs and NPAHs were highest in winter and lowest in summer. Fluoranthene and pyrene were the dominant PAHs and 1-nitropyrene was the dominant NPAH in all seasons, and these compounds were mainly emitted by diesel vehicles. The concentration ratio of benzo(a)pyrene (BaP) to benzo(ghi)perylene (BgPe) ((BaP)/(BgPe)) and of indeno(1,2,3-cd)pyrene (IDP) to the sum of IDP and benzo(ghi)perylene (BgPe) ((IDP)/((IDP)+(BgPe0) might still be useful indicators for identifying traffic emission sources today. Moreover, our results showed that the carcinogenic risk in all seasons was below the acceptable limit set by the WHO.

The red-crowned crane ( Grus japonensis ) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240 ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150 ng/g lipid weight), chlordane-related compounds (CHLs) (36 ng/g lipid weight), hexachlorobenzene (HCB) (16 ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4 ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8 ng/g lipid weight), and finally, Mirex (1.5 ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)- alpha -HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69).

An analytical method using high-performance liquid chromatography (HPLC) with fluorescence (FL) detection was developed for simultaneously analyzing 10 polycyclic aromatic hydrocarbons (PAHs) and 18 nitro-derivatives of PAHs (NPAHs). The two-dimensional HPLC system consists of an on-line clean-up and reduction for NPAHs in the 1st dimension, and separation of the PAHs and the reduced NPAHs and their FL detection in the 2nd dimension after column-switching. To identify an ideal clean-up column for removing sample matrix that may interfere with detection of the analytes, the characteristics of 8 reversed-phase columns were evaluated. The nitrophenylethyl (NPE)-bonded silica column was selected because of its shorter elution band and larger retention factors of the analytes due to strong dipole-dipole interactions. The amino-substituted PAHs (reduced NPAHs), PAHs and deuterated internal standards were separated on polymeric octadecyl-bonded silica (ODS) columns and by dual-channel detection within 120 min including clean-up and reduction steps. The limits of detection were 0.1-9.2 pg per injection for PAHs and 0.1-140 pg per injection for NPAHs. For validation, the method was applied to analyze crude extracts of fine particulate matter (PM2.5) samples and achieved good analytical precision and accuracy. Moreover, the standard reference material (SRM1649b, urban dust) was analyzed by this method and the observed concentrations of PAHs and NPAHs were similar to those in previous reports. Thus, the method developed herein has the potential to become a standard HPLC-based method, especially for NPAHs.

Airborne particulates were collected at an urban site (site 1) from 2004 to 2010 and at a suburban site (site 2) in 2010 in Beijing. Nine polycyclic aromatic hydrocarbons (PAHs) and five nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The concentrations of PAHs and NPAHs were higher in heating season than in non-heating season at the two sites. Both the concentrations of PAHs and NPAHs decreased in the non-heating season but only the concentrations of NPAHs decreased in heating season at site 1, from 2004 to 2010. These findings suggest that source control measures implemented by the city of Beijing helped to reduce air pollution in Beijing. The concentrations of PAHs increased at site 1 in 2010, possibly because of the transport of emissions from windward other areas, such as Shanxi province. Several diagnostic ratios of PAHs and NPAHs showed that the different sources contributed to Beijing's air pollution, although coal combustion was the main source in the heating season and vehicle emission was the main source in the non-heating season. An analysis of physical parameters at Beijing showed that high wind speed can remove atmospheric PAHs and NPAHs in the heating season and that high relative humidity can remove them in the non-heating season. © 2017 Elsevier Ltd, Embargo Period 12 months

A layered mesh inertial filter that was previously developed by the authors, was combined with an impactor, in which the collection efficiency curve overlaps that of the inertial filter, in order to provide a sharp-cut separation tool for aerosol nanoparticles operating at a moderate pressure drop of less than 10–15 kPa. The separation performance of the proposed “hybrid inertial filter” of the inertial filter and an impactor, such as cut-off size, steepness of the collection efficiency curve and pressure drop ΔP, was evaluated for a single nozzle type in order to confirm the proposed system. The performance of the single nozzle type, which can be used as a unit of a multi nozzle type, was compared with that of the previous type layered mesh inertial filter with a stainless steel fiber mat. The hybrid inertial filter was found to have a collection efficiency curve with a much better steepness at less ΔP compared to those of the previous type for particles with the same cut-off size: a cut-off size dp50 of 100 nm with steepness dp84/dp16 = 1.7, e.g., was obtained at ΔP ~12 kPa while dp84/dp16 = 2.4 at ~16 kPa was found for the previous type.

Diallylamine-maleic acid copolymer (DAM)-nonwoven fabric (DAM-f), a fibrous adsorbent, contains DAM with zwitter-ionic functional groups and forms a hydration layer on the surface. The aim of this report was to evaluate the adsorption selectivity of DAM-f to semi-volatile organic acid (C1-C5). In the aqueous phase, formic acid dissolved in the hydration layer bound to the imino group of DAM-f due to anion exchange interaction. In the gas phase, the adsorption amounts of organic acids increased with the exposure time. Moreover, the adsorption rate constants correlated with the air/water partition coefficients (log Kaw) for formic acid, propionic acid, butyric acid, valeric acid and isovaleric acid, except for acetic acid. These results indicate that DAM-f is highly selective to hydrophilic compounds which easily move from the air to the hydration layer of DAM-f.

Particulate matter (PM) was collected in three different areas, SY-1, SY-2, and SY-3, in Shenyang, China, during the warm and cold seasons from 2012 to 2014. SY-1 was located beside a thermal power plant, far from the central area. SY-2 was near a coal heating boiler on the main road, close to the central area. SY-3 was on the main road, without fixed emission sources. Nine PM-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed. The results showed that the mean concentration of total PAHs was higher in the cold season (92.6&ndash, 316 ng m&minus, 3) than in the warm season (18.4&ndash, 32.2 ng m&minus, 3). Five- and six-ring PAHs occupied a large percentage at all sites in the warm season, and four-ring PAHs were the dominant components in the cold season. Several diagnostic PAH ratios indicated that the main sources of PAHs in Shenyang in the warm and cold seasons were not only coal burning but also vehicle emission. In this study, we suggest that a benzo[a]pyrene/benzo[ghi]perylene ratio ([BaP]/[BgPe]) of 0.6 was a useful indicator to speculate the relative significance of coal burning and vehicle exhaust. Although the Shenyang government has undertaken actions to address air pollution, the PM and PAH concentrations did not decrease significantly compared to those in our previous studies. The cancer risk calculated from the BaP equivalent total concentration at all three sites in the warm and cold seasons exceeded the acceptable limit established by the US EPA.

This research investigated the distribution and contribution of polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) bound to particulate matter (PM) emitted from open burning of rice straw (RS) into the atmosphere in the north of Vietnam. The experiments were conducted to collect PM2.5 and total suspended particulates (TSP) prior to and during burning in the period of 2016&ndash, 2018 in suburban areas of Hanoi. Nine PAHs and 18 NPAHs were determined using the HPLC-FL system. The results showed that the proportion of RS burning seasonally affects the variation of PAHs emission in atmospheric environment. The levels of nine PAHs from RS burning were 254.4 &plusmn, 87.8 &micro, g g&minus, 1 for PM2.5 and 209.7 &plusmn, 89.5 &micro, 1 for TSP. We observed the fact that, although fluoranthene (Flu) was the most abundant PAH among detected PAHs both in PM2.5 and TSP, the enrichment of Flu in TSP from burning smoke was higher than that in PM2.5 while the contribution of benzo[a]pyrene (BaP) and indeno[1,2,3- cd]pyrene (IDP) in PM2.5 from burning smoke were much higher than those in TSP. This research found that 1-nitropyrene (1-NP) and 6-nitrochrysene (6-NC) emit from RS burning with the same range with those from wood burning. The 2-nitrofluorene (2-NF) and 2-nitropyrene (2-NP) released from RS burning as the secondary NPAHs. This research provides a comprehensive contribution characterization of PAHs and NPAHs in PM with different size emitted from traditional local rice straw burning in the north of Vietnam. The results help to clarify the environmental behavior of toxic organic compounds from RS burning in Southeast Asia.

Particulate matter (PM) is a major factor contributing to air quality deterioration that enters the atmosphere as a consequence of various natural and anthropogenic activities. In PM, polycyclic aromatic hydrocarbons (PAHs) represent a class of organic chemicals with at least two aromatic rings that are mainly directly emitted via the incomplete combustion of various organic materials. Numerous toxicological and epidemiological studies have proven adverse links between exposure to particulate matter-bound (PM-bound) PAHs and human health due to their carcinogenicity and mutagenicity. Among human exposure routes, inhalation is the main pathway regarding PM-bound PAHs in the atmosphere. Moreover, the concentrations of PM-bound PAHs differ among people, microenvironments and areas. Hence, understanding the behaviour of PM-bound PAHs in the atmosphere is crucial. However, because current techniques hardly monitor PAHs in real-time, timely feedback on PAHs including the characteristics of their concentration and composition, is not obtained via real-time analysis methods. Therefore, in this review, we summarize personal exposure, and indoor and outdoor PM-bound PAH concentrations for different participants, spaces, and cities worldwide in recent years. The main aims are to clarify the characteristics of PM-bound PAHs under different exposure conditions, in addition to the health effects and assessment methods of PAHs.

Eleven years (2005–2015) of data from long-term monitoring at a Japanese remote background site in Wajima, were analyzed to investigate temporal trends and sources. Water-soluble inorganic ions (WSIIs) were analyzed for aerosol chemical composition. The total WSIIs concentration was 7.93 ± 3.93 μg/m3, accounting for 42.3% of TSP mass, ranged from 11.4 to 93.9%. SO42− is the most abundant ion, contributing a total WSII mass from 18.0 to 79.8%, and non-sea-salt (nss-) SO42− contributed from 63.6% to 99.6% of total SO42−, which was related to human activities on the Asian continent and the effects of marine precursors in spring and summer, respectively. NO3− and NH4+ contribute 6.3 and 7.4% of the total WSIIs and were affected by long-range transport and local sources as well. The increasing trend of Na+ and Cl− indicates the increased influence of sea salt, which is caused by more frequent strong winds. K+ is mainly produced from biomass burning with a stable seasonal variation, Ca2+ as the characteristic ion of dust has the highest concentration in spring. Mg2+ comes from minerals and marine sources during spring and summer, respectively. This work describes in detail the annual change trend of the WSIIs of atmospheric particles in the Wajima area, seasonal characteristics, and source contributions, provide a comprehensive understanding of long-term variation in atmospheric particulate.

We have developed an original in vitro bioassay using teleost scale, that has osteoclasts, osteoblasts, and bone matrix as each marker: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Using this scale in vitro bioassay, we examined the effects of seawater polluted with highly concentrated polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) on osteoblastic and osteoclastic activities in the present study. Polluted seawater was collected from two sites (the Alexandria site on the Mediterranean Sea and the Suez Canal site on the Red Sea). Total levels of PAHs in the seawater from the Alexandria and Suez Canal sites were 1364.59 and 992.56 ng/l, respectively. We were able to detect NPAHs in both seawater samples. Total levels of NPAHs were detected in the seawater of the Alexandria site (12.749 ng/l) and the Suez Canal site (3.914 ng/l). Each sample of polluted seawater was added to culture medium at dilution rates of 50, 100, and 500, and incubated with the goldfish scales for 6 hrs. Thereafter, ALP and TRAP activities were measured. ALP activity was significantly suppressed by both polluted seawater samples diluted at least 500 times, but TRAP activity did not change. In addition, mRNA expressions of osteoblastic markers (ALP, osteocalcin, and the receptor activator of the NF-κB ligand) decreased significantly, as did the ALP enzyme activity. In fact, ALP activity decreased on treatment with PAHs and NPAHs. We conclude that seawater polluted with highly concentrated PAHs and NPAHs influences bone metabolism in teleosts. © 2016 Zoological Society of Japan., Embargo Period 12 months

Total suspended particulates (TSP) in the atmosphere were collected for 2 weeks during winter in Muroran, Hokkaido, Japan, a typical iron-manufacturing city. The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in TSP were determined by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. No relationship was observed between the atmospheric PAH and NPAH concentration, or the atmospheric PAH and TSP concentration. However, there was a tendency that the atmospheric PAH concentration was higher when the wind blew from the coke-oven plant. Furthermore, the concentration ratios of 1-nitropyrene to pyrene, which is a suitable indicator of the contribution made by automobiles and coal combustion systems to urban air particulates, were smaller in Muroran and the values were close to those observed in particulates from coal combustion systems. Therefore, these results show that the PAH and NPAH compositions for Muroran are characteristic of an iron-manufacturing city.

Surface water samples were collected at 15 sampling sites in the southeastern Japan Sea along the Japanese Archipelago for analysis of polycyclic aromatic hydrocarbons (PAHs). Water samples were fractionated by filtration through a glass fiber membrane (pore size 0.5 µm) and analyzed by high-performance liquid chromatography with fluorescence detection. Thirteen PAHs having 3 to 6 rings were found in the dissolved phase (DP) and 12 were found in the particulate phase (PP). The total (DP+PP) PAH concentration ranged from 6.83 to 13.81 ng/L with the mean±standard deviation (S.D.) concentration of 9.36±1.92 ng/L. The mean±S.D. PAH concentration in the DP and PP was 5.99±1.80 and 3.38±0.65 ng/L, respectively. Three-ring PAHs predominated in the DP, while the proportion of 4-ring PAHs was higher in the PP. The mean total PAH concentration in the southeastern Japan Sea was higher than the concentration in the northwestern Japan Sea (8.5 ng/L). The Tsushima Current, which originates from the East China Sea with higher PAH concentration, is considered to be responsible for this higher concentration.

Benzo[c]fluorene (BcFE) concentrations in benzene/ethanol extracts of airborne particulates were determined by high-performance liquid chromatography (HPLC) with fluorescence detection. HPLC conditions were as follows: columns, two ZORBAX Eclipse PAH (4.6 i.d. × 250 mm, 3.5 μm) and one Inertsil ODS-P (4.6 i.d. × 250 mm, 5 μm) in series; mobile phase, acetonitrile-water (98:2, v/v), 0.3 mL/min; detection wavelengths, excitation 309 nm, emission 354 nm. Particulate-phase BcFE concentrations in the atmosphere varied seasonally (winter > summer). The concentrations were 11000 ± 6100 pg m(-3) (winter) and 40 ± 12 pg m(-3) (summer) in Beijing, China, and 13 ± 5.0 pg m(-3) (winter) and 2.7 ± 0.52 pg m(-3) (summer), in Kanazawa, Japan. In both cities, the particulate-phase BcFE concentration in the atmosphere was lower than that of benzo[a]pyrene (BaP) by a factor of 0.03 - 0.43. However, the mutagenic contribution of particulate-phase BcFE in the atmosphere in winter calculated from the mutagenicity relative potency factor was greater than that of BaP.

Public concern regarding the transport of air pollutants from mainland East Asia to the leeward area by the prevailing westerlies in spring and winter monsoon has been growing in recent years. We collected total suspended particle (TSP) in Beijing, a metropolis of China located windward of Japan, in spring (late February 2011-May 2011) and in winter (November 2012-early February 2013), then analyzed metals, ions, and organic compounds and mutagenicity, and compared the pollution levels with samples collected at two Japanese metropolises (Osaka and Nagoya) during the same periods. The medians of concentration of TSP and other factors in Beijing were much larger than those in the Japanese metropolises. Especially, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were remarkably high in Beijing in winter, and the median of total PAHs concentration in Beijing was 62-63 times larger than that in the Japanese sites. The mutagenicity of TSP from Beijing toward Salmonella typhimurium YG1024, with and without a mammalian metabolic system (S9 mix), was 13-25 times higher than that from the Japanese sites in winter. These results suggest that air pollution levels in Beijing are very high compared with those at the two Japanese metropolises we evaluated. The diagnostic ratios of PAHs and nitrated polycyclic aromatic hydrocarbons (NPAHs) suggest that the major sources of PAHs and NPAHs in Beijing are different from those at the two Japanese sites in winter, and that the major source in Beijing is coal/biomass combustion.

Total suspended particulates were collected at a Japanese remote background site (Noto Air Monitoring Station; NAMS) on the Noto Peninsula from September 2004 to June 2014. Nine polycyclic aromatic hydrocarbons (PAHs) in the particulates (fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene and indeno[1,2,3-cd]pyrene) were determined by HPLC with fluorescence detection. The mean total concentrations of the nine PAHs in the cold season (November to May for the years 2004-2014) was 670 pg m-3 (range 37-4100 pg m-3). The mean total concentration in the warm season (June to October for the same period) was 170 pg m-3 (range 31-960 pg m-3). The atmospheric PAH level at NAMS decreased in recent years, although no significant change was found in the warm season. An analysis of meteorological conditions showed that the atmospheric PAHs at NAMS were long range transported from Northeast China in the cold seasons and were contributed to by Japanese domestic sources in the warm seasons. Lower concentration ratios of reactive PAHs to their isomers at NAMS also supported these results. Activities associated with the Beijing Olympic and Paralympic Games in 2008 and reconstruction after the 2007 Noto Hanto earthquake may have contributed to the yearly variations of atmospheric PAH levels at NAMS during the period 2007-2009. Source control measures implemented by the Chinese and Japanese governments appear to have been effective in decreasing the atmospheric PAH levels at NAMS in recent years. © 2015 Elsevier Ltd., Embargo Period 24 months