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For organic compounds in fine particles ( PM 2.5 ), the knowledge on their sources and formation processes are still rather limited because of labile characteristics. To assess the contribution of primary and secondary organic aerosols, it is necessary to utilize the behavior of organic markers. In this study, cluster analysis was applied to the seasonal variations of peaks in chromatogram for unquantitative organic compounds in PM 2.5 obtained by a gas chromatography/mass spectrometry (GC/MS) analysis after derivatization method. We used the PM 2.5 samples collected at Maebashi in Japan for four seasons. Based on cluster analysis, total 115 peaks were divided into nine clusters. The combination effects of the primary and secondary particles transported plume from urban atmosphere were found in two clusters for spring and summer. For dicarboxylic acids, C3 − C5 diacids were in same cluster, whereas C2 and C6 diacids were separated with the other cluster. These results show different trends of secondary formation for dicarboxylic acids. This approach might help to find a group of markers in organic aerosols and to classify potential source of secondary organic aerosols.

To understand the characteristics of secondary organic aerosols (SOAs) and estimate their impact on water-soluble organic carbon (WSOC) in urban areas in Japan, we measured 17 organic tracers using gas chromatography–mass spectrometry from particulate matter with an aerodynamic diameter smaller than 2.5 μm collected at five urban sites in Japan during spring and summer. Most anthropogenic, monoterpene-derived, and isoprene-derived SOA tracers showed meaningful correlations with potential ozone in both these seasons. These results indicate that oxidants play an important role in SOAs produced during both seasons in urban cities in Japan. WSOC was significantly affected by anthropogenic and monoterpene-derived SOAs during spring and three SOA groups during summer at most of the sites sampled. The total estimated secondary organic carbons (SOCs), including mono-aromatic, di-aromatic, monoterpene-derived, and isoprene-derived SOCs, could explain the WSOC fractions of 39–63% in spring and 46–54% in summer at each site. Notably, monoterpene-derived and mono-aromatic SOCs accounted for most of the total estimated SOCs in both spring (85–93%) and summer (75–82%) at each site. These results indicate that SOAs significantly impact WSOC concentrations during both these seasons at urban sites in Japan.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication. It is generally caused by gastric adenocarcinoma, and several molecules produced by tumor cells are reported to play important roles in its pathogenesis. We herein report an autopsy case of PTTM caused by urothelial carcinoma. Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and osteopontin were found to be expressed in both the primary tumor cells and metastatic cells in the PTTM lesions. These findings implicate the possible involvement of VEGF, PDGF, and osteopontin in the pathogenesis of PTTM caused by urothelial carcinoma.

Fine particles were collected at a suburban site in the inland Kanto plain, Japan, in the spring and winter of 2007, and the summer of 2008. Organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), inorganic ions, and water-soluble organic compounds (dicarboxylic acids and levoglucosan) were analyzed. The WSOC/OC ratio was the highest in summer, followed by in spring, suggesting that organic aerosols were influenced by aging. The concentrations of total diacids (C2–C9) in spring and summer were higher than in winter. In each season, WSOC showed a strong positive correlation with the total diacids. Levoglucosan, which is recognized as a biomass burning tracer, was observed in a considerably higher concentration in winter than in spring or summer. In winter, WSOC also showed a strong positive correlation with levoglucosan. These results indicate that secondary formation is important as a source of WSOC and OC especially in the warm seasons, although emissions from biomass burning also contribute to WSOC in winter. By using the combination of source profile for biomass burning emission and EC tracer method, OC derived from biomass combustion in winter was calculated to be 47% of OC and OC derived from secondary formation in summer was calculated to be 75% of OC.

In order to obtain more accurate assessments of global contamination by potentially toxic antimony (Sb) and the toxicological effects of Sb on ecosystems, speciation analysis of inorganic Sb species in size-classified airborne particulate matter (APM) was performed. Thirteen fractions of size-classified APM (with aerodynamic diameters: Dp 11 μm) were collected on a filter by using a multistage cascade impactor sampler. Speciation analysis of inorganic Sb(III) and Sb(V) was performed by using HPLC-ICP-MS. Portions of sample-loaded filters were sonicated with 30 mmol l−1 citric acid under purified N2 in order to avoid the oxidation of Sb(III) to Sb(V) during the extraction process. Sb(III) and Sb(V) were separated on a PRP-X100 anion exchange column using a mixture of 10 mmol l−1 EDTA and 1 mmol l−1 phthalic acid (pH 4.5) as a mobile phase, and they were subsequently detected by ICP-MS. The size distributions of the total Sb concentration exhibit a bimodal profile in which peaks corresponded to fine (0.50–0.70 μm) and coarse (3.6–5.2 μm) fractions. The speciation analysis demonstrated for the first time that Sb(III), which is the more toxic form, is dominated by coarse fractions whereas Sb(V) is distributed in both the fine and coarse fractions. The presented high-resolution size distributions of inorganic Sb species will provide helpful information in discussing both health risks by inhalation exposure to Sb and the extent of the effects of emission sources by atmospheric circulation.

Abrasion dusts from three types of commercially available non-steel brake pads were generated by a brake dynamometer at disk temperatures of 200, 300 and 4001C. The number concentration of the abrasion dusts and their aerodynamic diameters (Dp) were measured by using an aerodynamic particle sizer (APS) spectrometer with high temporal and size resolution. Simultaneously, the abrasion dusts were also collected based on their size by using an Andersen lowvolume sampler, and the concentrations of metallic elements (K, Ti, Fe, Cu, Zn, Sb and Ba) in the size-classified dusts were measured by ICP-AES and ICP-MS. The number distributions of the brake abrasion dusts had a peak at Dp values of 1 and 2mm; this peak shifted to the coarse side with an increase in the disk temperature. The mass distributions calculated from the number distributions have peaks between Dp values of 3 and 6mm. The shapes of the elemental mass distributions (Ti, Fe, Cu, Zn, Sb and Ba) in size-classified dusts were very similar to the total mass distributions of the brake abrasion dusts. These experimental results indicated that the properties of brake abrasion dusts were consistent with the characteristics of Sb-enriched fine airborne particulate matter. Based on these findings and statistical data, the estimation of Sb emission as airborne particulate matter from friction brakes was also discussed. r 2007 Elsevier Ltd. All rights reserved.

In this work, a complexation effect of Sb compounds with citric acid was observed using electrospray mass spectrometry (ES-MS). It was found that both Sb(III) and Sb(V) could form complexes readily with citric acid in an aqueous solution at room temperature. These complexes were found to be very stable in various matrices (moat water and aqueous extracts of airborne particulate matter), therefore, a novel HPLC-ICP-MS analytical method for the speciation of Sb(III) and Sb(V) in environmental samples was developed by using the observed complexation effect. Sb(III)- and Sb(V)-citrate complexes were separated on a PRP-X100 anion-exchange column with 10 mmol l−1 EDTA–1 mmol l−1 phthalic acid (pH 4.5) as a mobile phase. All complexes were retained on the separation column, and none of them eluted in the solvent front. Low detection limits of 0.05 µg l−1 and 0.07 µg l−1 were achieved for Sb(III) and Sb(V), respectively. The calibration curves were linear over the range of 1.0–250 µg l−1 for the investigated Sb species. The precisions, evaluated by using the relative standard deviation (%RSD) with a 2 µg l−1 standard solution, were 1.8% and 3.3% for Sb(III) and Sb(V), respectively. Several advantages of the developed method, such as improving chromatographic separation, stabilizing Sb compounds in a water sample, and preventing Sb(III) from oxidizing to Sb(V) during the ultrasonic-assisted and microwave-assisted extraction of an airborne particulate matter (APM) sample using 26 mmol l−1 citric acid as an extraction solvent, and alleviating the adsorption of Sb compounds on the sample surface, were observed. The developed method enabled us to detect the most toxic Sb specie, Sb(III), in an APM sample for the first time.

Abrasion tests were conducted using a brake dynamometer to determine the antimony (Sb) emission factor originating from automobiles. Abrasion dusts from commercially available brake pads (nonasbestos organic type) were emitted into an enclosed chamber under various braking conditions in terms of initial driving speed and deceleration. Suspended dusts inside the chamber were collected on a quartz fiber filter and weighed. From the experimental data, dust emission could be regressed as a function of the initial kinetic energy loading and the braking time. Using the regression function, the emission factors of brake abrasion dusts under the typical braking conditions (initial driving speed; 50 km/h, deceleration; 1.0 m/s2) were calculated as 5.8 mg/braking/car for PM10 and 3.9 mg/braking/car for PM2.5. The elemental composition of the collected dusts indicated that the fraction originating from disk wear contributed to approximately 30% of the suspended dusts. From these analytical results, it was concluded that the Sb emission factors originating from automobiles were approximately 32 microg Sb/braking/car for PM10 and 22 microg Sb/ braking/car for PM2.5. These essential data will contribute to the modeling of atmospheric Sb concentration alongside roadways and also to the better understanding of Sb source apportionment.