GC/ITMS measurement of carbonyls and multifunctional carbonyls in PM2.5 particles emitted from motor vehicles.

A method was developed and tested to identify and quantitate carbonyls and multifunctional carbonyls in fine particulate matter (PM2.5; <2.5 microm aerodynamic diameter). The method relies on ultrasonic extraction of particulate matter on filters at -8 degrees C; derivatization with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA), and PFBHA along with bis (trimethylsilyl) trifluoroacetamide (BSTFA); and detection of the derivatives by gas chromatography/ion trap mass spectrometry. Ultrasonic extraction of model compounds from enriched particles was affected by solvent polarity (water > methylene chloride > toluene-isopropanol (2 + 1, v/v). Water provided the highest recovery for dihydroxy acetone, pyruvic acid, and hydroxy acetone, compared to methylene chloride, and toluene-isopropanol. Lowering the ultrasonication bath temperature from 0 degrees to -8 degrees C improved the recoveries of the less water soluble and more volatile species-methacrolein, methyl vinyl ketone, 2,3-butanedione, and tolualdehyde. The power of the method was demonstrated by identification and quantitation of carbonyls and multifunctional carbonyls in sample extracts of fine particulate matter (PM2.5) collected in the Caldecott tunnel, CA. The identities of crotonaldehyde, 2,3-butanedione, glyoxal, 9H-fluoren-9-one, glycolaldehyde, glyoxylic acid, levulinic acid, and 3-hydroxybenzaldehyde were confirmed by comparing the relative retention time and mass spectra of the analyte in the sample extract with an authentic standard. Quantitation of crotonaldehyde, glyoxal, 2,3-butanedione, glyoxylic acid, and levulinic acid was accomplished. This is the first report of glyoxylic acid, levulinic acid, and 3-hydroxybenzaldheyde in PM2.5 particles sampled in a roadway tunnel. It is also the first report of a C10 carbonyl with the molecular formula of C10H16O2, a hydroxy carbonyl with the molecular formula of C17H21NO2, and a hydroxy or dihydroxy carbonyl with the molecular formula of C16H14O2 or C9H10O3. The high-molecular weight hydroxy carbonyls, which were found only in the heavy-duty (diesel) bore, may be tracers of diesel emissions in air.     

Chemical fractionation of elements in airborne particulate matter: primary results on PM10 and PM2.5 samples in the Lazio region (central Italy)

This paper describes how a two-step chemical fractionation method that allows the determination of 17 elements in airborne particulate matter, has been applied to a monitoring campaign of PM10 and PM2.5 in the Lazio region (Italy). This method involved an extraction in a pH buffered aqueous solution followed by a microwave-assisted acid digestion of the residue. With respect to the determination of the total elemental contents, the evaluation of a soluble fraction provides more reliable information on the presence and of the destiny of heavy metals in the environment. Furthermore, the pH buffered extraction conditions chosen, rendered the results independent of the intrinsic acidity of the collected samples and, although the chemical fractionation has a purely operational function, it facilitates the study of the relationship between the distribution of solubility and the different emission sources. Results are discussed in relation to the different concentration and the different degrees of solubility of the elements observed in two sampling sites; one in an urban and one in a rural environment. Since in-parallel sampling of PM2.5 and PM10 were performed in both sites, the influence of particle size is also discussed. Behaviour of some tracers deriving from both vehicular traffic, with particular attention to re-suspended road dusts, and naturally generated particulate matter, such as marine aerosol and Saharian dust, are discussed.     

Airborne particulates (PM2.5/PM10) monitoring in Korea by instrumental neutron activation analysis

Instrumental neutron activation analysis was used for the analysis of 25 trace elements in airborne particulate matter (PM) for air pollution monitoring. For the collection of air samples, the Gent stacked filter unit low volume sampler and two types of Nuclepore polycarbonate filters were employed. Samples were collected at selected sampling dates in suburban and industrial regions of Daejon city in the Republic of Korea. Mass concentrations and black carbon of PM were measured, and enrichment factors were calculated. The results were used to describe the emission sources and their correlation patterns.     

2-IPMA Ameliorates PM2.5-Induced Inflammation by Promoting Primary Ciliogenesis in RPE Cells

Primary cilia mediate the interactions between cells and external stresses. Thus, dysregulation of primary cilia is implicated in various ciliopathies, e.g., degeneration of the retina caused by dysregulation of the photoreceptor primary cilium. Particulate matter (PM) can cause epithelium injury and endothelial dysfunction by increasing oxidative stress and inflammatory responses. Previously, we showed that PM disrupts the formation of primary cilia in retinal pigment epithelium (RPE) cells. In the present study, we identified 2-isopropylmalic acid (2-IPMA) as a novel inducer of primary ciliogenesis from a metabolite library screening. Both ciliated cells and primary cilium length were increased in 2-IPMA-treated RPE cells. Notably, 2-IPMA strongly promoted primary ciliogenesis and restored PM2.5-induced dysgenesis of primary cilia in RPE cells. Both excessive reactive oxygen species (ROS) generation and activation of a stress kinase, JNK, by PM2.5 were reduced by 2-IPMA. Moreover, 2-IPMA inhibited proinflammatory cytokine production, i.e., IL-6 and TNF-α, induced by PM2.5 in RPE cells. Taken together, our data suggest that 2-IPMA ameliorates PM2.5-induced inflammation by promoting primary ciliogenesis in RPE cells.     

Assessment of the concentrations of U and Th in PM2.5 from Mexico City and their potential human health risk

Journal of Radioanalytical and Nuclear Chemistry - This is one of the first studies in small particulate matter (PM2.5) by inductively coupled plasma sector field mass spectrometry to measure the...     

Combination of active components enhances the efficacy of Prunella in prevention and treatment of lung cancer

The efficacy of Prunella extracts in the prevention and treatment of lung cancer has been attributed to different components. In this study, an "active components combination model" hypothesis was proposed to explain the anti-tumor activity of Prunella. The efficacy of Prunella extracts from different regions was compared in vitro and in vivo, and the TNF-α activity in serum of tumor-bearing mice was also evaluated. High performance liquid chromatography (HPLC) was used to analyze the extracts and identify 26 common peaks. Prunella samples from different regions were classified by the cluster analysis method; both P. vulgaris L. from Bozhou and P. asiatica Nakai from Nanjing, which had the highest activities, were further divided into different classes. Six peaks from the HPLC analysis were very similar, and were identified as caffeic acid, rosmarinic acid, rutin, quercetin, oleanolic acid and ursolic acid. The total ratio of these compounds in Prunella from Bozhou and Nanjing were 1.0:14.7:3.9:1.0:4.4:1.4 and 1.0:14.8:4.0:0.8:5.6:1.8, respectively. Total triterpenes and total phenols in Prunella were separated by macroporous resin purification for activity studies. The results showed that total triterpenes and total phenols had anti-lung cancer activity and their combination significantly enhanced the activity. In addition, the combination also significantly increased the TNF-α content compared to total triterpenes or total phenols. The results indicated that the efficacy of Prunella against lung cancer was attributable to multiple components acting at an optimal ratio.     

Pollution characteristics of ambient PM2.5-bound PAHs and NPAHs in a typical winter time period in Taiyuan

The pollution characteristics of ambient fine particulate matter（PM2.5） containing polycyclic aromatic hydrocarbons（PAHs） and nitrated PAHs（NPAHs） in samples collected during a typical winter time period in Taiyuan of China were investigated.The obtained results revealed that the mean mass concentrations of PM2.5,SPAHs（sum of 16 PAHs） and SNPAHs（sum of 3 NPAHs） on PM2.5were161.4 mg/m3,119.8 ng/m3and 0.446 ng/m3,respectively.Diagnostic ratios of PAHs and NPAHs implied that coal consumption might be the main source of the PM2.5pollution.The measured PM2.5mass concentrations,BaP equivalent toxicity（28.632 ng/m3） and individual carcinogenicity index（3.14 10 5） were much higher than those of the recommended safety standards.     

Neutron activation analysis: Still a reference method for air particulate matter measurements

At ITN, PM10 and PM2.5 aerosols were collected on Nuclepore^® polycarbonate filters of 47 mm diameter, using Gent samplers at 15–17 l/min air flux. Filters were analyzed by INAA and PIXE. The availability of certified filters was very scarce, viz.: (1) fly ash embedded in a methyl cellulose 47 mm foil 10 µm thick, BCR CRM128, (2) particle-size reduced air particulate matter (APM) to simulate PM2.5 aerosol matter deposited on a 47 mm polycarbonate filter membrane, NIST SRM 2783. The high price and scarcity of APM standards did not permit their frequent use for analytical quality control. At ITN, to control the filter results' accuracy, the chemical elements potassium, iron and zinc, determined by both techniques, were systematically compared. After a few improvements introduced in INAA, this technique was now considered at ITN as the reference technique in air particulate measurements. Comparison of INAA to PIXE was discussed. Compared to previously reported situation it was concluded that the results were in better agreement for iron and zinc, and potassium values were still biased to the same extent as before.     

Study of seasonal variation and source characteristic of PM10 of Shanghai urban atmosphere using PIXE

This study is a one-year monitoring of the inhalable particulate matter (PM10) of Shanghai (from January 2006 to December 2006) to study PM10 pollution. Proton-induced X-ray emission (PIXE) was used to investigate the chemical elements in Shanghai PM10. The study finds seasonal variation in both mass concentration and of chemical elements in PM10. The results of the enrichment factor show that the chemical elements in the inhalable particles could be divided into two categories, soil elements from earth crust and anthropogenic pollution elements. The high enrichment factors suggest that anthropogenic activities were the dominant source for elements such as S, Cu, Cl, Zn, Pb and Br. Strong correlation of K, Ca, Fe and Ti, from factor analysis, indicates these elements coming from earth crust or soil, S, Zn and Pb from industrial pollution and/or traffic and Cl from coal combustion.     

Djulis (Chenopodium formosanum) and Its Bioactive Compounds Protect Human Lung Epithelial A549 Cells from Oxidative Injury Induced by Particulate Matter via Nrf2 Signaling Pathway

The protective effects of water extracts of djulis (Chenopodium formosanum) (WECF) and their bioactive compounds on particulate matter (PM)-induced oxidative injury in A549 cells via the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling were investigated. WECF at 50–300 µg/mL protected A549 cells from PM-induced cytotoxicity. The cytoprotection of WECF was associated with decreases in reactive oxygen species (ROS) generation, thiobarbituric acid reactive substances (TBARS) formation, and increases in superoxide dismutase (SOD) activity and glutathione (GSH) contents. WECF increased Nrf2 and heme oxygenase-1 (HO-1) expression in A549 cells exposed to PM. SP600125 (a JNK inhibitor) and U0126 (an ERK inhibitor) attenuated the WECF-induced Nrf2 and HO-1 expression. According to the HPLC-MS/MS analysis, rutin (2219.7 µg/g) and quercetin derivatives (2648.2 µg/g) were the most abundant bioactive compounds present in WECF. Rutin and quercetin ameliorated PM-induced oxidative stress in the cells. Collectively, the bioactive compounds present in WECF can protect A549 cells from PM-induced oxidative injury by upregulating Nrf2 and HO-1 via activation of the ERK and JUN signaling pathways.     

Identification of genotoxic compounds in the airborne particulate matter endowed by small aerodynamic diameter in the city of Catania (Italy)

Airborne particulate matter (PM) is one of the most important polluting factors in the atmosphere containing solid particles generated during the combustion processes. PM, due to the particle size, is easily inhaled and constitutes a potential hazard for the human health. We previously documented, using in vitro cell culture systems, cytogenetic damages caused by exposure to a non-fractionated PM in two different areas from the city of Catania (Sicily, Italy). In the present work, the PM was fractionated in six different sub-fractions, and the relative extractable organic matters (EOM) were analyzed in order to quantify the presence of Polycyclic Aromatic Hydrocarbons (PHAs), a well known class of genotoxic agents. More than 70% of the total EOM was found in the PM with aerodynamic diameters less than 3.5 microm (PM35), and about 60% of the total EOM was detected between PM0.14 and PM1.2. Also the large amount of all the analyzed PAHs were found between the PM0.14 and PM1.2. The obtained data indicates that the genotoxic effect previously shown on mammalian cells (Chinese hamster epithelial liver cells) should be due, in the large part, to the PM with smaller particle size, namely less than PM1.2.     

Effects of the ambient fine particulate matter (PM2.5) exposure on urinary metabolic profiles in rats using UPLC-Q-TOF-MS

The pathogenesis of PM2.5 was evaluated on rats in model groups using a metabonomic method by UPLC-Q-TOF-MS and 17 potential endogenous metablites were identified. The primary metabolism pathways involved pentose and glucuronate interconversions, starch and sucrose metabolism, tryptophan metabolism, tyrosine metabolism, phenylalanine metabolism, purine metabolism, acetaminophen metabolism pathway, retinol metabolism and valproic acid metabolism pathway.     

Correlations among inorganic and organic elements in particulate matter (PM10) in urban area of Venezia-Mestre

Concentrations of inhalable particulate matter (PM10), Pb, Zn, Pt, Ce, Cd, Se and of Benzo(a)pyrene (BaP) were determined in three locations near Venice from September 2000 to September 2001. Meteorological conditions were considered during the sampling period. All components showed higher concentrations during winter, except for Cd and Se in the two sites at Mestre. Spatial and temporal variations were observed. There were correlations between Pb and Zn and PM10, Cd and Se, Pb and BaP and, in the main street sampling site, also between BaP and Pt. Their possible sources of emission are discussed on the basis of correlations among elements.     

利用代谢组学研究大气细颗粒物的生殖毒性效应

大气细颗粒物(PM2.5)污染已成为严峻的环境问题,探究PM2.5的毒性效应和机理变得尤为重要.本研究利用基于液相色谱/质谱的代谢组学技术,分析经PM2.5悬混液气管滴注暴露后成年雄性大鼠睾丸代谢组的全局变化,采用偏最小二乘判别分析法和非参数检验进行统计分析.结果表明,PM2.5暴露组大鼠睾丸的油提和水提代谢指纹谱均可与对照组实现准确区分,表明PM2.5暴露对大鼠睾丸的整体代谢网络产生了显著影响,最终鉴定出56个差异代谢物.通路分析显示,PM2.5暴露会引起大鼠睾丸的氨基酸和核苷酸代谢紊乱、类固醇激素代谢失衡以及脂类代谢异常,而这些重要通路可能是PM2.5生殖毒性的关键分子事件.     

Chemical speciation of plutonium in seawater

Concentrations of particulate and dissolved plutonium in seawater were determined together with strong organic ligands (SOL) in particulate matter (PM). The concentration of particulate 239,240Pu in surface waters of the Western North Pacific ranged from 0.03 to 0.3 mBq m(-3) during the period from 1987 to 1997. The percentage of particulate Pu to total Pu in seawater was less than 10% in surface waters, whereas its portions were less than 1% in deep waters. In order to characterize particulate Pu in seawater, the relationships between particulate Pu, dissolved Pu and SOL concentrations in surface PM were examined. The result reveals that particulate Pu was linearly related to the SOL concentration independent of dissolved Pu concentration. Mass balance analysis suggests that a dominant chemical form of Pu in surface PM, which may exist as Pu(IV), is a complex with strong organic ligands in PM.     

The impact of fine particulate matter (PM) on various beneficial functions of human endometrial stem cells through its key regulator SERPINB2

Fine particulate matter (PM) has a small diameter but a large surface area; thus, it may have broad toxic effects that subsequently damage many tissues of the human body. Interestingly, many studies have suggested that the recent decline in female fertility could be associated with increased PM exposure. However, the precise mechanisms underlying the negative effects of PM exposure on female fertility are still a matter of debate. A previous study demonstrated that resident stem cell deficiency limits the cyclic regenerative capacity of the endometrium and subsequently increases the pregnancy failure rate. Therefore, we hypothesized that PM exposure induces endometrial tissue damage and subsequently reduces the pregnancy rate by inhibiting various beneficial functions of local endometrial stem cells. Consistent with our hypothesis, we showed for the first time that PM exposure significantly inhibits various beneficial functions of endometrial stem cells, such as their self-renewal, transdifferentiation, and migratory capacities, in vitro and in vivo through the PM target gene SERPINB2, which has recently been shown to be involved in multiple stem cell functions. In addition, the PM-induced inhibitory effects on the beneficial functions of endometrial stem cells were significantly diminished by SERPINB2 depletion. Our findings may facilitate the development of promising therapeutic strategies for improving reproductive outcomes in infertile women.Subject terms: Stem-cell research, Adult stem cells     

Ferrochelatase Deficiency Abrogated the Enhancement of Aminolevulinic Acid‐mediated Protoporphyrin IX by Iron Chelator Deferoxamine

Aminolevulinic acid (ALA) is a prodrug that is metabolized in the heme biosynthesis pathway to produce protoporphyrin IX (PpIX) for tumor fluorescence detection and photodynamic therapy (PDT). The iron chelator deferoxamine (DFO) has been widely used to enhance PpIX accumulation by inhibiting the iron‐dependent bioconversion of PpIX to heme, a reaction catalyzed by ferrochelatase (FECH). Tumor response to DFO treatment is known to be highly variable, and some tumors even show no response. Given the fact that tumors often exhibit reduced FECH expression/enzymatic activity, we examined how reducing FECH level affected the DFO enhancement effect. Our results showed that reducing FECH level by silencing FECH in SkBr3 breast cancer cells completely abrogated the enhancement effect of DFO. Although DFO enhanced ALA‐PpIX fluorescence and PDT response in SkBr3 vector control cells, it caused a similar increase in MCF10A breast epithelial cells, resulting in no net gain in the selectivity toward tumor cells. We also found that DFO treatment induced less increase in ALA‐PpIX fluorescence in tumor cells with lower FECH activity (MDA‐MB‐231, Hs 578T) than in tumor cells with higher FECH activity (MDA‐MB‐453). Our study demonstrates that FECH activity is an important determinant of tumor response to DFO treatment.     

Assaying particle-bound polycyclic aromatic hydrocarbons from archived PM2.5 filters

Airborne particulate matter contains numerous organic species, including several polycyclic aromatic hydrocarbons (PAHs) that are known or suspected carcinogens. Existing methods for measuring airborne PAHs are complex and costly, primarily because they are designed to collect both gas-phase and particle-phase PAH constituents. Here, we report an assay for measuring particle-bound PAHs in archived filters from the network of U.S. monitoring stations for particles less than 2.5 microm in diameter (PM2.5), without the need for deploying specialized samplers. PAHs are extracted from Teflon filters with dichloromethane, concentrated, and measured at trace levels using gas chromatography-mass spectrometry. Although PAHs with 3-6 aromatic rings can be assayed, results are only unambiguously accurate for compounds with 5- or 6-rings, due to variable vaporization losses of the more volatile 3- and 4-ring compounds during sampling and/or storage. The method was evaluated for sensitivity, recovery, precision, and agreement of paired air samples, using PM2.5 samplers locally in Chapel Hill, NC. Additionally, three sets of archived samples were analyzed from a study of PM2.5 in the Czech Republic. Levels of some 4-ring and all 5- and 6-ring PAHs in both the local and Czech samples were consistent with published results from investigations employing PAH-specific air samplers. This work strongly suggests that assessment of particle-bound 5- and 6-ring PAHs from archived PM2.5 filters is quantitatively robust. The assay may also be useful for selected 4-ring compounds, notably chrysene and benzo(a)anthracene, if PM2.5 filters are stored under refrigeration.     

智能石墨消解–ICP–MS法测定空气PM2.5中的Pb和Cd

建立电感耦合等离子体质谱(ICP–MS)测定空气PM2.5中的Pb和Cd元素的分析方法。采用连续β射线–DHS PM2.5大气颗粒物浓度监测仪采集空气中的PM2.5,以智能石墨消解PM2.5滤膜样品,ICP–MS测定其中的Pb和Cd元素含量。在优化的仪器条件下,元素Pb和Cd标准曲线的线性相关系数均为0.999 9,检出限分别为0.018,0.52ng/m3,满足HJ 657–2013的要求。Pb和Cd的加标回收率分别为95.8%~101.4%,99.3%~104.9%,测定结果的相对标准偏差分别为4.20%和2.38%(n=6)。对滤膜标准样品进行了测定,测定结果与标准值一致。该方法测定结果准确、可靠,可用于测定空气PM2.5中的Pb和Cd。     

Analysis of voltammetric data for the evaluation of seasonal changes of the Ni, Cd, Pb and Cu content in atmospheric particulate PM2.5

In this paper, the preliminary results of a study on concentration of heavy metals in PM2.5 (atmospheric particles with aerodynamic diameter less than 2.5 microm) fractions of atmospheric particulate matter, sampled in Milan, are presented. This work aims to develop an electroanalytical method to analyse Pb, Cu, Cd and Ni in PM2.5 and to investigate seasonal and weekly trends in the amount of PM2.5 and its composition for considered metals. The samples have been selected within the seasons ranging from September 2002 to November 2003 so that they represent the possible seasonal changes; the samples within this period have been chosen in order to have data relevant to both working days and holidays. The determination of Cd, Pb and Cu has been carried out by Differential Pulse Anodic Stripping Voltammetry, whereas the concentration of Ni has been determined by Differential Pulse Adsorptive Cathodic Stripping Voltammetry. The concentrations of the metals in the sampled atmosphere and in the PM2.5 have been evaluated; through ANOVA possible seasonal or weekly variations in the above cited concentrations have been investigated.