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2. Oxidant production from source-oriented particulate matter - Part 1: Oxidative potential using the dithiothreitol (DTT) assay

Author

Charrier, JG, Richards-Henderson, NK, Bein, KJ, McFall, AS, Wexler, AS, and Anastasio, C

Subjects
Meteorology & Atmospheric Sciences, Atmospheric Sciences, Astronomical and Space Sciences
Abstract

Recent epidemiological evidence supports the hypothesis that health effects from inhalation of ambient particulate matter (PM) are governed by more than just the mass of PM inhaled. Both specific chemical components and sources have been identified as important contributors to mortality and hospital admissions, even when these end points are unrelated to PM mass. Sources may cause adverse health effects via their ability to produce reactive oxygen species in the body, possibly due to the transition metal content of the PM. Our goal is to quantify the oxidative potential of ambient particle sources collected during two seasons in Fresno, CA, using the dithiothreitol (DTT) assay. We collected PM from different sources or source combinations into different ChemVol (CV) samplers in real time using a novel source-oriented sampling technique based on single-particle mass spectrometry. We segregated the particles from each source-oriented mixture into two size fractions - ultrafine (Dp ≤ 0.17 μm) and submicron fine (0.17 μm ≤ Dp ≤ 1.0 μm) - and measured metals and the rate of DTT loss in each PM extract. We find that the mass-normalized oxidative potential of different sources varies by up to a factor of 8 and that submicron fine PM typically has a larger mass-normalized oxidative potential than ultrafine PM from the same source. Vehicular emissions, regional source mix, commute hours, daytime mixed layer, and nighttime inversion sources exhibit the highest mass-normalized oxidative potential. When we apportion DTT activity for total PM sampled to specific chemical compounds, soluble copper accounts for roughly 50% of total air-volume-normalized oxidative potential, soluble manganese accounts for 20%, and other unknown species, likely including quinones and other organics, account for 30%. During nighttime, soluble copper and manganese largely explain the oxidative potential of PM, while daytime has a larger contribution from unknown (likely organic) species.

Published
2015

3. Oxidant production from source-oriented particulate matter – Part 1: Oxidative potential using the dithiothreitol (DTT) assay

Author

Charrier, JG, Richards-Henderson, NK, Bein, KJ, McFall, AS, Wexler, AS, and Anastasio, C

Subjects
Environmental Sciences, Pollution and Contamination, Climate-Related Exposures and Conditions
Abstract

Abstract. Recent epidemiological evidence supports the hypothesis that health effects from inhalation of ambient particulate matter (PM) are governed by more than just the mass of PM inhaled. Both specific chemical components and sources have been identified as important contributors to mortality and hospital admissions, even when these endpoints are unrelated to PM mass. Sources may cause adverse health effects via their ability to produce reactive oxygen species, possibly due to the transition metal content of the PM. Our goal is to quantify the oxidative potential of ambient particle sources collected during two seasons in Fresno, CA using the dithiothreitol (DTT) assay. We collected PM from different sources or source combinations into different ChemVol (CV) samplers in real time using a novel source-oriented sampling technique based on single particle mass spectrometry. We segregated the particles from each source-oriented mixture into two size fractions – ultrafine (Dp ≤ 0.17 μm) and submicron fine (0.17 μm ≤ Dp ≤ 1.0 μm) – and measured metals and the rate of DTT loss in each PM extract. We find that the mass-normalized oxidative potential of different sources varies by up to a actor of 8 and that submicron fine PM typically has a larger mass-normalized oxidative potential than ultrafine PM from the same source. Vehicular Emissions, Regional Source Mix, Commute Hours, Daytime Mixed Layer and Nighttime Inversion sources exhibit the highest mass-normalized oxidative potential. When we apportion the volume-normalized oxidative potential, which also accounts for the source's prevalence, cooking sources account for 18–29% of the total DTT loss while mobile (traffic) sources account for 16–28%. When we apportion DTT activity for total PM sampled to specific chemical compounds, soluble copper accounts for roughly 50% of total air-volume-normalized oxidative potential, soluble manganese accounts for 20%, and other unknown species, likely including quinones and other organics, account for 30%. During nighttime, soluble copper and manganese largely explain the oxidative potential of PM, while daytime has a larger contribution from unknown (likely organic) species.

Published
2014

4. Combustion-derived flame generated ultrafine soot generates reactive oxygen species and activates Nrf2 antioxidants differently in neonatal and adult rat lungs.

Author

Chan, JKW, Charrier, JG, Kodani, SD, Vogel, CF, Kado, SY, Anderson, DS, Anastasio, C, and Van Winkle, LS

Subjects
HOOH, Hydrogen peroxide, Hydroxyl radical, Lung development, OH, O2, Reactive oxygen species, ROS, Superoxide
Abstract

Urban particulate matter (PM) has been epidemiologically correlated with multiple cardiopulmonary morbidities and mortalities, in sensitive populations. Children exposed to PM are more likely to develop respiratory infections and asthma. Although PM originates from natural and anthropogenic sources, vehicle exhaust rich in polycyclic aromatic hydrocarbons (PAH) can be a dominant contributor to the PM2.5 and PM0.1 fractions and has been implicated in the generation of reactive oxygen species (ROS). Current studies of ambient PM are confounded by the variable nature of PM, so we utilized a previously characterized ethylene-combusted premixed flame particles (PFP) with consistent and reproducible physiochemical properties and 1) measured the oxidative potential of PFP compared to ambient PM, 2) determined the ability of PFPs to generate oxidative stress and activate the transcription factor using in vitro and ex vivo models, and 3) we correlated these responses with antioxidant enzyme expression in vivo. We compared oxidative stress response (HMOX1) and antioxidant enzyme (SOD1, SOD2, CAT, and PRDX6) expression in vivo by performing a time-course study in 7-day old neonatal and young adult rats exposed to a single 6-hour exposure to 22.4 μg/m3 PFPs. We showed that PFP is a potent ROS generator that induces oxidative stress and activates Nrf2. Induction of the oxidative stress responsive enzyme HMOX1 in vitro was mediated through Nrf2 activation and was variably upregulated in both ages. Furthermore, antioxidant enzyme expression had age and lung compartment variations post exposure. Of particular interest was SOD1, which had mRNA and protein upregulation in adult parenchyma, but lacked a similar response in neonates. We conclude that PFPs are effective ROS generators, comparable to urban ambient PM2.5, that induce oxidative stress in neonatal and adult rat lungs. PFPs upregulate a select set of antioxidant enzymes in young adult animals, that are unaffected in neonates. We conclude that the inability of neonatal animals to upregulate the antioxidant response may, in part, explain enhanced their susceptibility to ultrafine particles, such as PFP.

Published
2013

7. An overview of air-snow exchange at Summit, Greenland: Recent experiments and findings

Author

Dibb, JE, Albert, M, Anastasio, C, Atlas, E, Beyersdorf, AJ, Blake, NJ, Blake, DR, Bocquet, F, Burkhart, JF, Chen, G, Cohen, L, Conway, TJ, Courville, Z, Frey, MM, Friel, DK, Galbavy, ES, Hall, S, Hastings, MG, Helmig, D, Greg Huey, L, Hutterli, MA, Jarvis, JC, Lefer, BL, Meinardi, S, Neff, W, Oltmans, SJ, Sherwood Rowland, F, Sjostedt, SJ, Steig, EJ, Swanson, AL, and Tanner, DJ

Subjects
Meteorology & Atmospheric Sciences, Environmental Engineering, Atmospheric Sciences, Statistics
Published
2007

8. Enhanced photodegradation of dimethoxybenzene isomers in/on ice compared to in aqueous solution

Author

Hullar, T, Hullar, T, Tran, T, Chen, Z, Bononi, F, Palmer, O, Donadio, D, Anastasio, C, Hullar, T, Hullar, T, Tran, T, Chen, Z, Bononi, F, Palmer, O, Donadio, D, and Anastasio, C

Abstract

Photochemical reactions of contaminants in snow and ice can be important sinks for organic and inorganic compounds deposited onto snow from the atmosphere and sources for photoproducts released from snowpacks into the atmosphere. Snow contaminants can be found in the bulk ice matrix, in internal liquid-like regions (LLRs), or in quasi-liquid layers (QLLs) at the air-ice interface, where they can readily exchange with the firn air. Some studies have reported that direct photochemical reactions occur faster in LLRs and QLLs than in aqueous solution, while others have found similar rates. Here, we measure the photodegradation rate constants for loss of the three dimethoxybenzene isomers under varying experimental conditions, including in aqueous solution, in LLRs, and at the air-ice interface of nature-identical snow. Relative to aqueous solution, we find modest photodegradation enhancements (3- and 6-fold) in LLRs for two of the isomers and larger enhancements (15- to 30-fold) at the air-ice interface for all three isomers. We use computational modeling to assess the impact of light absorbance changes on photodegradation rate enhancements at the interface. We find small (2-5gnm) bathochromic (red) absorbance shifts at the interface relative to in solution, which increases light absorption, but this factor only accounts for less than 50g% of the measured rate constant enhancements. The major factor responsible for photodegradation rate enhancements at the air-ice interface appears to be more efficient photodecay: estimated dimethoxybenzene quantum yields are 6- to 24-fold larger at the interface compared to in aqueous solution and account for the majority (51g%-96g%) of the observed enhancements. Using a hypothetical model compound with an assumed Gaussian-shaped absorbance peak, we find that a shift in the peak to higher or lower wavelengths can have a minor to substantial impact on photodecay rate constants, depending on the original location of the peak and the magn

Published
2022

9. Chapter 7 Frontiers in assessing the role of chemical speciation and natural attenuation on the Bioavailability of Contaminants in the Terrestrial Environment

Author

Gerson, A.R., primary, Anastasio, C., additional, Crowe, S., additional, Fowle, D., additional, Guo, B., additional, Kennedy, I., additional, Lombi, E., additional, Nico, P.S., additional, Marcus, M.A., additional, Martin, R.R., additional, Naftel, S.J., additional, Nelson, A.J., additional, Paktunc, D., additional, Roberts, J.A., additional, Weisener, C.G., additional, and Werner, M.L., additional

Published
2008
Full Text
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10. An Overview of Snow Photochemistry: Evidence, Mechanisms and Impacts

Author

Grannas, A. M, Jones, A. E, Dibb, J, Ammann, M, Anastasio, C, Beine, H. J, Bergin, M, Bottenheim, J, Boxe, C. S, Carver, G, Chen, G, Crawford, J. H, Domine, F, Frey, M. M, Guzman, M. I, Heard, D. E, Helmig, D, Hoffmann, M. R, Honrath, R. E, Huey, L. G, Hutterli, M, Jacobi, H.-W, Klan, P, McConnell, J, and Plane, J

Subjects
Meteorology And Climatology
Abstract

It has been shown that sunlit snow and ice plays an important role in processing atmospheric species. Photochemical production of a variety of chemicals has recently been reported to occur in snow/ice and the release of these photochemically generated species may significantly impact the chemistry of the overlying atmosphere. Nitrogen oxide and oxidant precursor fluxes have been measured in a number of snow covered environments, where in some cases the emissions significantly impact the overlying boundary layer. For example, photochemical ozone production (such as that occurring in polluted mid-latitudes) of 3-4 ppbv/day has been observed at South Pole, due to high OH and NO levels present in a relatively small boundary layer. Field and laboratory experiments have determined that the origin of the observed NOx flux is the photochemistry of nitrate within the snowpack, however some details of the mechanism have not yet been elucidated. A variety of low molecular weight organic compounds have been shown to be emitted from sunlit snowpacks, the source of which has been proposed to be either direct or indirect photo-oxidation of natural organic materials present in the snow. Although myriad studies have observed active processing of species within irradiated snowpacks, the fundamental chemistry occurring remains poorly understood. Here we consider the nature of snow at a fundamental, physical level; photochemical processes within snow and the caveats needed for comparison to atmospheric photochemistry; our current understanding of nitrogen, oxidant, halogen and organic photochemistry within snow; the current limitations faced by the field and implications for the future.

Published
2007

13. The effect of cations on NO2production from the photolysis of aqueous thin water films of nitrate salts

Author

Richards-Henderson, NK, Anderson, C, Anastasio, C, and Finlayson-Pitts, BJ

Abstract

© the Owner Societies 2015. The photochemistry of nitrate ions in bulk aqueous solution is well known, yet recent evidence suggests that the photolysis of nitrate may be more efficient at the air-water interface. Whether and how this surface enhancement is altered by the presence of different cations is not known. In the present studies, thin aqueous films of nitrate salts with different cations were deposited on the walls of a Teflon chamber and irradiated with 311 nm light at 298 K. The films were generated by nebulizing aqueous 0.5 M solutions of the nitrate salts and the generation of gas-phase NO2was monitored with time. The nitrate salts fall into three groups based on their observed rate of NO2formation (RNO2): (1) RbNO3and KNO3, which readily produce NO2(RNO2> 3 ppb min-1), (2) Ca(NO3)2, which produces NO2more slowly (RNO2< 1 ppb min-1), and (3) Mg(NO3)2and NaNO3, which lie between the other two groups. Neither differences in the UV-visible spectra of the nitrate salt solutions nor the results of bulk-phase photolysis studies could explain the differences in the rates of NO2production between these three groups. These experimental results, combined with some insights from previous molecular dynamic simulations and vibrational sum frequency generation studies, show that cations may impact the concentration of nitrate ions in the interface region, thereby directly impacting the effective quantum yields for nitrate ions.

Published
2015

18. Soluble, light-absorbing species in snow at Barrow, Alaska

Author

Beine, H., Anastasio, C., Esposito, G., Patten, K., Wilkening, E., Domine, F., Voisin, D., Barret, M., Houdier, S., Hall, S., Department of Land, Air and Water Resources, University of California [Davis] (UC Davis), University of California-University of California, Istituto sull’Inquinamento Atmosferico (CNR-IIA), Consiglio Nazionale delle Ricerche (CNR), Wilson K8 School, CHANG, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Atmospheric Chemistry Division [Boulder], National Center for Atmospheric Research [Boulder] (NCAR), NSF ATM-0807702, IPEV grant 1017-OASIS, OASIS (Ocean-Atmosphere-Sea Ice-Snowpack) program, CHANG (CHANG), Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
snow pac, OASIS, light absorption, chromophores, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, HULIS
Abstract

International audience; As part of the international multidisciplinary Ocean - Atmosphere - Sea Ice - Snowpack (OASIS) program we analyzed more than 500 terrestrial (melted) snow samples near Barrow, AK between February and April 2009 for light absorption, as well as H2O2 and inorganic anion concentrations. For light absorption in the photochemically active region (300-450 nm) of surface snows, H2O2 and NO3− make minor contributions (combined < 9% typically), while HUmic LIke Substances (HULIS) and unknown chromophores each account for approximately half of the total absorption. We have identified four main sources for our residual chromophores (i.e., species other than H2O2 or NO3−): (1) vegetation and organic debris impact mostly the lowest 20 cm of the snowpack, (2) marine inputs, which are identified by high Cl− and SO42− contents, (3) deposition of diamond dust to surface snow, and (4) gas-phase exchange between the atmosphere and surface snow layers. The snow surfaces, and accompanying chromophore concentrations, are strongly modulated by winds and snowfall at Barrow. However, even with these physical controls on light absorption, we see an overall decline of light absorption in near-surface snow during the 7 weeks of our campaign, likely due to photo-bleaching of chromophores. While HULIS and unknown chromophores dominate light absorption by soluble species in Barrow snow, we know little about the photochemistry of these species, and thus we as a community are probably overlooking many snowpack photochemical reactions.

Published
2011

27. Determinants of mother-to-infant human immunodeficiency virus 1 transmission before and after the introduction of zidovudine prophylaxis

Author

De Martino, The Italian Register for Human Immunodeficiency Virus Infection in C. h. i. l. d. r. e. n., Galli, M, Tovo, L, Gabiano, Pa, Pezzotti, C., Wagner, P, Rezza, Tm, Osimani, Partecipants: G., De Mattia, D, Di Bari, C, Ruggeri, M, Baldi, F, Ciccia, M, Lanari, M, Masi, M, Venturi, M, Battisti, V, Duse, L, Chiriaco, M, Cavallini, Pg, Dessi, R, Pintor, C, Anastasio, C, Sabatino, E, Sticca, G, Pomero, M, Bezzi, G, Chiappini, T, E, Luca, De, Gervaso, M, Cecchi, P, Bassetti, Mt, Gotta, D, Rosso, C, Timitilli, R, Tondo, A, Mussini, U, Bricalli, P, Bucceri, D, Ferraris, A, Giovannini, G, Mosca, M, Lipreri, F, Guarino, R, Plebani, A, Riva, A, Riva, E, Vigano, S, Zuccotti, A, Cellini, Gv, Buffolano, M, Guarino, W, Tarallo, A., D'Elia, L, Giaquinto, R, Rampon, C, O, Dalle, Nogare, Romano, Er, Caselli, A, Maccabruni, D, A, and Consolini, Rita

Published
2002

28. Rapid disease progression in HIV-1 perinatally infected children born to mothers receiving zidovudine monotherapy during pregnancy

Author

Author: de Martino, Galli, M, Tovo, L, Gabiano, Pa, Zappa, C, M, Group Author: Italian Register HIV Infect Children Italian Register: Osimani, Zizzadoro, P, P, Mattia, De, Ruggeri, D, Lanari, M, Dalla, Vecchia, Masi, S, Baldi, M, Battisti, F, Duse, L, Crispino, M, Uberti, P, Bresciani, E, Chiriacò, E, Pintor, Pg, Dedoni, C, Loriano, M, Dessi, D, Anastasio, C, Sabatino, L, Sticca, G, Berrino, M, Lodato, R, Vierucci, A, Farina, A, S, Luca, De, Maria, De, Fioredda, A, Boni, F, Marazzi, S, Pontali, Mg, Forni, E, Gotta, Gi, Tasso, C, Gambaretto, L, Meo, G, Plebani, A, Pinzani, A, Salvini, R, Marchisio, F, Massironi, P, Tornaghi, E, Zuccotti, R, Riva, Gv, Carlis, De, Ferraris, S, Bucceri, G, Liprieri, A, Cellini, R, Guarino, M, Pignata, A, Tarallo, C, Giaquinto, L, Ruga, C, Rampon, E, Romano, O, Benaglia, A, Caselli, G, Maccabruni, D, A, and Consolini, Rita

Published
1999

29. An overview of snow photochemistry: evidence, mechanisms and impacts

Author

Grannas, A. M., Jones, A. E., Dibb, J., Ammann, M., Anastasio, C., Beine, H. J., Bergin, M., Bottenheim, J., Boxe, C. S., Carver, G., Chen, G., Crawford, J. H., Dominé, F., Frey, M. M., Guzmán, M. I., Heard, D. E., Helmig, D., Hoffmann, M. R., Honrath, R. E., Huey, L. G., Hutterli, M., Jacobi, H. W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P. B., Simpson, W. R., Sodeau, J. R., von Glasow, R., Weller, R., Wolff, E. W., Zhu, T., Grannas, A. M., Jones, A. E., Dibb, J., Ammann, M., Anastasio, C., Beine, H. J., Bergin, M., Bottenheim, J., Boxe, C. S., Carver, G., Chen, G., Crawford, J. H., Dominé, F., Frey, M. M., Guzmán, M. I., Heard, D. E., Helmig, D., Hoffmann, M. R., Honrath, R. E., Huey, L. G., Hutterli, M., Jacobi, H. W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P. B., Simpson, W. R., Sodeau, J. R., von Glasow, R., Weller, R., Wolff, E. W., and Zhu, T.

Abstract

It has been shown that sunlit snow and ice plays an important role in processing atmospheric species. Photochemical production of a variety of chemicals has recently been reported to occur in snow/ice and the release of these photochemically generated species may significantly impact the chemistry of the overlying atmosphere. Nitrogen oxide and oxidant precursor fluxes have been measured in a number of snow covered environments, where in some cases the emissions significantly impact the overlying boundary layer. For example, photochemical ozone production (such as that occurring in polluted mid-latitudes) of 3–4 ppbv/day has been observed at South Pole, due to high OH and NO levels present in a relatively shallow boundary layer. Field and laboratory experiments have determined that the origin of the observed NOx flux is the photochemistry of nitrate within the snowpack, however some details of the mechanism have not yet been elucidated. A variety of low molecular weight organic compounds have been shown to be emitted from sunlit snowpacks, the source of which has been proposed to be either direct or indirect photo-oxidation of natural organic materials present in the snow. Although myriad studies have observed active processing of species within irradiated snowpacks, the fundamental chemistry occurring remains poorly understood. Here we consider the nature of snow at a fundamental, physical level; photochemical processes within snow and the caveats needed for comparison to atmospheric photochemistry; our current understanding of nitrogen, oxidant, halogen and organic photochemistry within snow; the current limitations faced by the field and implications for the future.

Published
2007

30. An overview of snow photochemistry: evidence, mechanisms and impacts

Author

Grannas, A.M., Jones, Anna E., Dibb, J., Ammann, M., Anastasio, C., Beine, H.J., Bergin, M., Bottenheim, J., Boxe, C.S., Carver, G., Chen, G., Crawford, J.H., Dominé, F., Frey, M.M., Guzmán, M.I., Heard, D.E., Helmig, D., Hoffmann, M.R., Honarth, R.E., Huey, L.G., Hutterli, Manuel, Jacobi, H.W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P.B., Simpson, W.R., Sodeau, J.R., von Glasow, R., Weller, R., Wolff, Eric W., Zhu, T., Grannas, A.M., Jones, Anna E., Dibb, J., Ammann, M., Anastasio, C., Beine, H.J., Bergin, M., Bottenheim, J., Boxe, C.S., Carver, G., Chen, G., Crawford, J.H., Dominé, F., Frey, M.M., Guzmán, M.I., Heard, D.E., Helmig, D., Hoffmann, M.R., Honarth, R.E., Huey, L.G., Hutterli, Manuel, Jacobi, H.W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P.B., Simpson, W.R., Sodeau, J.R., von Glasow, R., Weller, R., Wolff, Eric W., and Zhu, T.

Abstract

It has been shown that sunlit snow and ice plays an important role in processing atmospheric species. Photochemical production of a variety of chemicals has recently been reported to occur in snow/ice and the release of these photochemically generated species may significantly impact the chemistry of the overlying atmosphere. Nitrogen oxide and oxidant precursor fluxes have been measured in a number of snow covered environments, where in some cases the emissions significantly impact the overlying boundary layer. For example, photochemical ozone production (such as that occurring in polluted mid-latitudes) of 3–4 ppbv/day has been observed at South Pole, due to high OH and NO levels present in a relatively shallow boundary layer. Field and laboratory experiments have determined that the origin of the observed NOx flux is the photochemistry of nitrate within the snowpack, however some details of the mechanism have not yet been elucidated. A variety of low molecular weight organic compounds have been shown to be emitted from sunlit snowpacks, the source of which has been proposed to be either direct or indirect photo-oxidation of natural organic materials present in the snow. Although myriad studies have observed active processing of species within irradiated snowpacks, the fundamental chemistry occurring remains poorly understood. Here we consider the nature of snow at a fundamental, physical level; photochemical processes within snow and the caveats needed for comparison to atmospheric photochemistry; our current understanding of nitrogen, oxidant, halogen and organic photochemistry within snow; the current limitations faced by the field and implications for the future.

Published
2007

34. Hydroxyl radical and NOxproduction rates, black carbon concentrations and light-absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Author

France, J. L., primary, Reay, H. J., additional, King, M. D., additional, Voisin, D., additional, Jacobi, H. W., additional, Domine, F., additional, Beine, H., additional, Anastasio, C., additional, MacArthur, A., additional, and Lee-Taylor, J., additional

Published
2012
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35. Cost effective prophylaxys of postoperative nausea and vomiting by anesthetic premedication

Author

Rodolà F, Cannelli G, Barbi S, Forte E, Anastasio C, and Salvatore VAGNONI

Subjects
Adult, Male, Postoperative Complications, Adolescent, Double-Blind Method, Vomiting, Cost-Benefit Analysis, Antiemetics, Humans, Female, Nausea, Promethazine, Preanesthetic Medication
Abstract

Postoperative emesis is a common daily problem in anesthetic practice. Authors report their experience about prevention of PONV (postoperative nausea and vomiting) with the association of different drugs in premedication, and suggest Promethazine as an effective and inexpensive medication to prevent PONV in orthopedic surgery.

Published
1995

48. An overview of snow photochemistry: evidence, mechanisms and impacts

Author

Grannas, A. M., primary, Jones, A. E., additional, Dibb, J., additional, Ammann, M., additional, Anastasio, C., additional, Beine, H. J., additional, Bergin, M., additional, Bottenheim, J., additional, Boxe, C. S., additional, Carver, G., additional, Chen, G., additional, Crawford, J. H., additional, Dominé, F., additional, Frey, M. M., additional, Guzmán, M. I., additional, Heard, D. E., additional, Helmig, D., additional, Hoffmann, M. R., additional, Honrath, R. E., additional, Huey, L. G., additional, Hutterli, M., additional, Jacobi, H. W., additional, Klán, P., additional, Lefer, B., additional, McConnell, J., additional, Plane, J., additional, Sander, R., additional, Savarino, J., additional, Shepson, P. B., additional, Simpson, W. R., additional, Sodeau, J. R., additional, von Glasow, R., additional, Weller, R., additional, Wolff, E. W., additional, and Zhu, T., additional

Published
2007
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