Marianne Glasius

Exposure to Ultrafine Particles from Ambient Air and Oxidative Stress–Induced DNA Damage

Background Particulate matter, especially ultrafine particles (UFPs), may cause health effects through generation of oxidative stress, with resulting damage to DNA and other macromolecules. Objective We investigated oxidative damage to DNA and related repair capacity in peripheral blood mononuclear cells (PBMCs) during controlled exposure to urban air particles with assignment of number concentration (NC) to four size modes with average diameters of 12, 23, 57, and 212 nm. Design Twenty-nine healthy adults participated in a randomized, two-factor cross-over study with or without biking exercise for 180 min and with exposure to particles (NC 6169-15362/cm3) or filtered air (NC 91-542/cm3) for 24 hr. Methods The levels of DNA strand breaks (SBs), oxidized purines as formamidopyrimidine DNA glycolase (FPG) sites, and activity of 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1) in PBMCs were measured by the Comet assay. mRNA levels of OGG1, nucleoside diphosphate linked moiety X-type motif 1 (NUDT1), and heme oxygenase-1 (HO1) were determined by real-time reverse transcriptase–polymerase chain reaction. Results Exposure to UFPs for 6 and 24 hr significantly increased the levels of SBs and FPG sites, with a further insignificant increase after physical exercise. The OGG1 activity and expression of OGG1, NUDT1, and HO1 were unaltered. There was a significant dose–response relationship between NC and DNA damage, with the 57-nm mode as the major contributor to effects. Concomitant exposure to ozone, nitrogen oxides, and carbon monoxide had no influence. Conclusion Our results indicate that UFPs, especially the 57-nm soot fraction from vehicle emissions, causes systemic oxidative stress with damage to DNA and no apparent compensatory up-regulation of DNA repair within 24 hr.

Polybrominated diphenyl ethers (PBDEs) in marine fish and blue mussels from southern Greenland.

Levels of polybrominated diphenyl ethers (PBDEs) have not previously been reported in Greenland. In this study shorthorn sculpins (Myoxocephalus scorpius) were sampled at three locations in southern Greenland; Usuk (no population), Igaliko (population 40) and Qaqortoq (population 3200). Furthermore uvak (Gadus ogac), spotted wolffish (Anarhichas minor), starry ray (Raja radiata), and blue mussels (Mytilus edulis) were collected at Usuk. Pooled samples of fish liver and blue mussel were analysed for lower brominated PBDEs (BDE-47, BDE-99, BDE-100 and BDE-153). The highest PBDE levels were found in Qaqortoq followed by Igaliko and Usuk. The measured sum PBDE concentrations in shorthorn sculpin collected at Qaqortoq, Igaliko and Usuk, were 8.2, 3.1 and 2.1 all in units of microg kg(-1) wet weight. In female and male uvak collected at Usuk PBDE levels of 7.1 and 12.0 microg kg(-1) wet weight were measured, while the concentrations were 1.2 microg kg(-1) in spotted wolffish, 1.4 microg kg(-1) in starry ray and 0.11 microg kg(-1) in blue mussels from the same locality all measured on a wet weight basis. The highest concentrations were measured in uvak, a top-predator on fish indicating that PBDEs are biomagnifying. The level of tetra-hexa BDEs is 15-24 times lower than PCB levels measured in the same samples, except for shorthorn sculpin collected at Qaqortoq, where the level of PBDEs was 40 times lower than the level of PCBs. The high concentration of PCBs relative to PBDEs in shorthorn sculpin collected at Qaqortoq signifies a local emission of PCBs, which is higher than the local emission of PBDEs.

The Molecular Identification of Organic Compounds in the Atmosphere: State of the Art and Challenges

Atmosphere: State of the Art and Challenges Barbara Nozier̀e,*,† Markus Kalberer,*,‡ Magda Claeys,* James Allan, Barbara D’Anna,† Stefano Decesari, Emanuela Finessi, Marianne Glasius, Irena Grgic,́ Jacqueline F. Hamilton, Thorsten Hoffmann, Yoshiteru Iinuma, Mohammed Jaoui, Ariane Kahnt, Christopher J. Kampf, Ivan Kourtchev,‡ Willy Maenhaut, Nicholas Marsden, Sanna Saarikoski, Jürgen Schnelle-Kreis, Jason D. Surratt, Sönke Szidat, Rafal Szmigielski, and Armin Wisthaler †Ircelyon/CNRS and Universite ́ Lyon 1, 69626 Villeurbanne Cedex, France ‡University of Cambridge, Cambridge CB2 1EW, United Kingdom University of Antwerp, 2000 Antwerp, Belgium The University of Manchester & National Centre for Atmospheric Science, Manchester M13 9PL, United Kingdom Istituto ISAC C.N.R., I-40129 Bologna, Italy University of York, York YO10 5DD, United Kingdom University of Aarhus, 8000 Aarhus C, Denmark National Institute of Chemistry, 1000 Ljubljana, Slovenia Johannes Gutenberg-Universitaẗ, 55122 Mainz, Germany Leibniz-Institut für Troposphar̈enforschung, 04318 Leipzig, Germany Alion Science & Technology, McLean, Virginia 22102, United States Max Planck Institute for Chemistry, 55128 Mainz, Germany Ghent University, 9000 Gent, Belgium Finnish Meteorological Institute, FI-00101 Helsinki, Finland Helmholtz Zentrum München, D-85764 Neuherberg, Germany University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States University of Bern, 3012 Bern, Switzerland Institute of Physical Chemistry PAS, Warsaw 01-224, Poland University of Oslo, 0316 Oslo, Norway

Singlet Oxygen Sensor Green®: Photochemical Behavior in Solution and in a Mammalian Cell

The development of efficient and selective luminescent probes for reactive oxygen species, particularly for singlet molecular oxygen, is currently of great importance. In this study, the photochemical behavior of Singlet Oxygen Sensor Green® (SOSG), a commercially available fluorescent probe for singlet oxygen, was examined. Despite published claims to the contrary, the data presented herein indicate that SOSG can, in fact, be incorporated into a living mammalian cell. However, for a number of reasons, caution must be exercised when using SOSG. First, it is shown that the immediate product of the reaction between SOSG and singlet oxygen is, itself, an efficient singlet oxygen photosensitizer. Second, SOSG appears to efficiently bind to proteins which, in turn, can influence uptake by a cell as well as behavior in the cell. As such, incorrect use of SOSG can yield misleading data on yields of photosensitized singlet oxygen production, and can also lead to photooxygenation‐dependent adverse effects in the system being investigated.

KINETIC STUDY OF GAS-PHASE REACTIONS OF PINONALDEHYDE AND STRUCTURALLY RELATED COMPOUNDS

Rate constants for the reactions of OH, NO3, and O3 with pinonaldehyde and the structurally related compounds 3-methylbutanal, 3-methylbutan-2-one, cyclobutylmethylketone, and 2,2,3-trimethyl-cyclobutyl-1-ethanone have been measured at using on-line Fourier transform infrared spectroscopy. The rate constants obtained for the reactions with pinonaldehyde were: ,

Determination of polar terpene oxidation products in aerosols by liquid chromatography-ion trap mass spectrometry

Abstract A new method for the determination of polar terpene oxidation products in secondary aerosols is described. It is based on collection of particles on PTFE filters and extraction with dichloromethane followed by analysis with liquid chromatography–ion-trap mass spectrometry (MSn) using pneumatically assisted electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) with the ion-trap operated in the product scan mode. Separations were achieved on a C18 reversed-phase column with methanol–water (0.1% acetic acid) as eluent. The method has a high sensitivity (instrument detection limit 0.7–7 pg/μl at S/N=3) and precision (5–10%) and a good linearity. Acidic oxidation products produce strong signals with ESI. They appear as negative quasimolecular ions [M−H]−, acetate adducts [M+CH3COO]− and molecular clusters [2M−H]−. In the MS2 mode these acids show strong signals from neutral loss of CO2: [M−H−CO2]−, and/or weaker signals from loss of H2O: [M−H−H2O]−, [M−H−H2O−CO2]−. Mass spectra were recorded by APCI for a number of oxygenated terpenoid standards containing keto groups, hydroxy groups, aldehyde groups, or epoxy groups. These compounds give intense signals as their positive quasimolecular ions [M+H]+, methanol adducts [M+H+CH3OH]+ and fragments from loss of water, such as [M+H−H2O]+, [M+H+CH3OH−H2O]+ and [M+H−2H2O]+. By MS2 and MS3 neutral loss of H2O and 2H2O is observed. The method has been tested in analysis of aerosol from O3–α-pinene and O3–myrtenol and has been proved to compare well with classical methods based on derivatisation and gas chromatography mass spectrometry. Three new compounds, tentatively identified in aerosol are reported here for the first time: 10-hydroxypinonic acid, 9-hydroxynorpinonic acid and pinalic 4-acid.

Exposure to ambient concentrations of particulate air pollution does not influence vascular function or inflammatory pathways in young healthy individuals.

BackgroundParticulate air pollution is associated with increased risk of cardiovascular events although the involved mechanisms are poorly understood. The objective of the present study was to investigate the effects of controlled exposure to ambient air fine and ultrafine particles on microvascular function and biomarkers related to inflammation, haemostasis and lipid and protein oxidation.MethodsTwenty-nine subjects participated in a randomized, two-factor crossover study with or without biking exercise for 180 minutes and with 24 hour exposure to particle rich (number concentrations, NC: 11600 ± 5600 per cm3, mass concentrations: 13.8 ± 7.4 μg/m3 and 10.5 ± 4.8 μg/m3 for PM10-2.5 and PM2.5, respectively) or particle filtered (NC: 555 ± 1053 per cm3) air collected above a busy street. Microvascular function was assessed non-invasively by measuring digital peripheral artery tone following arm ischemia. Biomarkers included haemoglobin, red blood cells, platelet count, coagulation factors, C-reactive protein, fibrinogen, interleukin-6, tumour necrosis factor α, lag time to copper-induced oxidation of plasma lipids and protein oxidation measured as 2-aminoadipic semialdehyde in plasma.ResultsNo statistically significant differences were observed on microvascular function or the biomarkers after exposure to particle rich or particle filtered air.ConclusionThis study indicates that exposure to air pollution particles at outdoor concentrations is not associated with detectable systemic inflammation, lipid or protein oxidation, altered haemostasis or microvascular function in young healthy participants.

Observational insights into aerosol formation from isoprene.

Atmospheric photooxidation of isoprene is an important source of secondary organic aerosol (SOA) and there is increasing evidence that anthropogenic oxidant emissions can enhance this SOA formation. In this work, we use ambient observations of organosulfates formed from isoprene epoxydiols (IEPOX) and methacrylic acid epoxide (MAE) and a broad suite of chemical measurements to investigate the relative importance of nitrogen oxide (NO/NO2) and hydroperoxyl (HO2) SOA formation pathways from isoprene at a forested site in California. In contrast to IEPOX, the calculated production rate of MAE was observed to be independent of temperature. This is the result of the very fast thermolysis of MPAN at high temperatures that affects the distribution of the MPAN reservoir (MPAN / MPA radical) reducing the fraction that can react with OH to form MAE and subsequently SOA (F(MAE formation)). The strong temperature dependence of F(MAE formation) helps to explain our observations of similar concentrations of IEPOX-derived organosulfates (IEPOX-OS; ~1 ng m(-3)) and MAE-derived organosulfates (MAE-OS; ~1 ng m(-3)) under cooler conditions (lower isoprene concentrations) and much higher IEPOX-OS (~20 ng m(-3)) relative to MAE-OS (<0.0005 ng m(-3)) at higher temperatures (higher isoprene concentrations). A kinetic model of IEPOX and MAE loss showed that MAE forms 10-100 times more ring-opening products than IEPOX and that both are strongly dependent on aerosol water content when aerosol pH is constant. However, the higher fraction of MAE ring opening products does not compensate for the lower MAE production under warmer conditions (higher isoprene concentrations) resulting in lower formation of MAE-derived products relative to IEPOX at the surface. In regions of high NOx, high isoprene emissions and strong vertical mixing the slower MPAN thermolysis rate aloft could increase the fraction of MPAN that forms MAE resulting in a vertically varying isoprene SOA source.

Organosulfates as Tracers for Secondary Organic Aerosol (SOA) Formation from 2-Methyl-3-Buten-2-ol (MBO) in the Atmosphere

2-Methyl-3-buten-2-ol (MBO) is an important biogenic volatile organic compound (BVOC) emitted by pine trees and a potential precursor of atmospheric secondary organic aerosol (SOA) in forested regions. In the present study, hydroxyl radical (OH)-initiated oxidation of MBO was examined in smog chambers under varied initial nitric oxide (NO) and aerosol acidity levels. Results indicate measurable SOA from MBO under low-NO conditions. Moreover, increasing aerosol acidity was found to enhance MBO SOA. Chemical characterization of laboratory-generated MBO SOA reveals that an organosulfate species (C5H12O6S, MW 200) formed and was substantially enhanced with elevated aerosol acidity. Ambient fine aerosol (PM2.5) samples collected from the BEARPEX campaign during 2007 and 2009, as well as from the BEACHON-RoMBAS campaign during 2011, were also analyzed. The MBO-derived organosulfate characterized from laboratory-generated aerosol was observed in PM2.5 collected from these campaigns, demonstrating that it is a molecular tracer for MBO-initiated SOA in the atmosphere. Furthermore, mass concentrations of the MBO-derived organosulfate are well correlated with MBO mixing ratio, temperature, and acidity in the field campaigns. Importantly, this compound accounted for an average of 0.25% and as high as 1% of the total organic aerosol mass during BEARPEX 2009. An epoxide intermediate generated under low-NO conditions is tentatively proposed to produce MBO SOA.

Alginate oligosaccharides: enzymatic preparation and antioxidant property evaluation.

Alginate oligosaccharides (AOs) prepared from alginate, by alginate lyase-mediated depolymerization, were structurally characterized by mass spectrometry, infrared spectrometry and thin layer chromatography. Studies of their antioxidant activities revealed that AOs were able to completely (100%) inhibit lipid oxidation in emulsions, superiorly to ascorbic acid (89% inhibition). AOs showed radical scavenging activity towards ABTṠ, hydroxyl, and superoxide radicals, which might explain their excellent antioxidant activity. The radical scavenging activity is suggested to originate mainly from the presence of the conjugated alkene acid structure formed during enzymatic depolymerization. According to the resonance hybrid theory, the parent radicals of AOs are delocalized through allylic rearrangement, and as a consequence, the reactive intermediates are stabilized. AOs were weak ferrous ion chelators. This work demonstrated that AOs obtained from a facile enzymatic treatment of abundant alginate is an excellent natural antioxidant, which may find applications in the food industry.