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Sample records for ozone exposure enhances

  1. Enhanced response to ozone exposure during the follicular phase of the menstrual cycle

    Energy Technology Data Exchange (ETDEWEB)

    Fox, S.D.; Adams, W.C.; Brookes, K.A.; Lasley, B.L. (Univ. of Calfornia, Davis (United States))

    1993-08-01

    Exposure to ozone (O[sub 3]), a toxic component of photochemical smog, results in significant airway inflammation, respiratory discomfort, and pulmonary function impairment. These effects can be reduced via pretreatment with anti-inflammatory agents. Progesterone, a gonadal steroid, is known to reduce general inflammation in the uterine endometrium. However, it is not known whether fluctuation in blood levels of progesterone, which are experienced during the normal female menstrual cycle, could alter O[sub 3] inflammatory-induced pulmonary responses. In this study, we tested the hypothesis that young, adult females are more responsive to O[sub 3] inhalation with respect to pulmonary function impairment during their follicular (F) menstrual phase when progesterone levels are lowest that during their mid-luteal (ML) phase when progesterone levels are highest. Nine subjects with normal ovarian function were exposed in random order for 1 hour each to filtered air and to 0.30 ppm O[sub 3] in their F and ML menstrual phases. Ozone responsiveness was measured by percent change in pulmonary function from pre- to postexposure. Significant gas concentration effects (filtered air versus O[sub 3]) were observed for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV[sub 1]), and forced expiratory flow between 25 and 75% of FVC (FEF[sub 25-75]), showed a significant menstrual phase and gas concentration interaction effect, with larger decrements observed in the F menstrual phase when progesterone concentrations were significantly lower. We conclude that young, adult females appear to be more responsive to acute O[sub 3] exposure during the F phase than during the ML phase of their menstrual cycles. This difference in pulmonary function response could be related to the anti-inflammatory effects of increased progesterone concentrations during the luteal phase.

  2. Modeled population exposures to ozone

    Data.gov (United States)

    U.S. Environmental Protection Agency — Population exposures to ozone from APEX modeling for combinations of potential future air quality and demographic change scenarios. This dataset is not publicly...

  3. Ozone's impact on public health: Contributions from indoor exposures to ozone and products of ozone-initiated chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.

    2006-01-01

    OBJECTIVES: The associations between ozone concentrations measured outdoors and both morbidity and mortality may be partially due to indoor exposures to ozone and ozone-initiated oxidation products. In this article I examine the contributions of such indoor exposures to overall ozone-related heal...

  4. Tropospheric Enhancement of Ozone over the UAE

    Science.gov (United States)

    Abbasi, Naveed Ali; Majeed, Tariq; Iqbal, Mazhar; Kaminski, Jacek; Struzewska, Joanna; Durka, Pawel; Tarasick, David; Davies, Jonathan

    2015-04-01

    We use the Global Environmental Multiscale - Air Quality (GEM-AQ) model to interpret the vertical profiles of ozone acquired with ozone sounding experiments at the meteorological site located at the Abu Dhabi airport. The purpose of this study is to gain insight into the chemical and dynamical structures in the atmosphere of this unique subtropical location (latitude 24.45N; longitude 54.22E). Ozone observations for years 2012 - 2013 reveal elevated ozone abundances in the range from 70 ppbv to 120 ppbv near 500-400 hPa during summer. The ozone abundances in other seasons are much lower than these values. The preliminary results indicate that summertime enhancement in ozone is associated with the Arabian anticyclones centered over the Zagros Mountains in Iran and the Asir and Hijaz Mountain ranges in Saudi Arabia, and is consistent with TES observations of deuterated water. The model also shows considerable seasonal variation in the tropospheric ozone which is transported from the stratosphere by dynamical processes. The domestic production of ozone in the middle troposphere is estimated and compared GEM-AQ model. It is estimated that about 40-50% of ozone in the UAE is transported from the neighbouring petrochemical industries in the Gulf region. We will present ozone sounding data and GEM-AQ results including a discussion on the high levels of the tropospheric ozone responsible for contaminating the air quality in the UAE. This work is supported by National Research Foundation, UAE.

  5. Iron decreases biological effects of ozone exposure

    Science.gov (United States)

    CONTEXT: Ozone (0(3)) exposure is associated with a disruption of iron homeostasis and increased availability of this metal which potentially contributes to an oxidative stress and biologicaleffects. OBJECTIVE: We tested the postulate that increased concentrations of iron in c...

  6. Within season and carry-over effects following exposure of grassland species mixtures to increasing background ozone

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, Felicity, E-mail: fhay@ceh.ac.uk [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW (United Kingdom); Mills, Gina; Harmens, Harry; Wyness, Kirsten [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW (United Kingdom)

    2011-10-15

    Few studies have investigated effects of increased background ozone in the absence of episodic peaks, despite a predicted increase throughout the northern hemisphere over the coming decades. In this study Leontodon hispidus was grown with Anthoxanthum odoratum or Dactylis glomerata and exposed in the UK to one of eight background ozone concentrations for 20 weeks in solardomes. Seasonal mean ozone concentrations ranged from 21.4 to 102.5 ppb. Ozone-induced senescence of L. hispidus was enhanced when grown with the more open canopy of A. odoratum compared to the denser growing D. glomerata. There was increased cover with increasing ozone exposure for both A. odoratum and D. glomerata, which resulted in an increase in the grass:Leontodon cover ratio in both community types. Carry-over effects of the ozone exposure were observed, including delayed winter die-back of L. hispidus and acceleration in the progression from flowers to seed-heads in the year following ozone exposure. - Highlights: > Increased background ozone concentrations increased the grass:forb cover ratio. > Competing grass species influenced ozone enhanced senescence of Leontodon hispidus. > Ozone delayed winter die-back of leaves of L. hispidus. > Flowering was accelerated for L. hispidus in the year following ozone exposure. - Increased background ozone enhanced leaf senescence and caused carry-over effects including reduced winter die-back and an acceleration in flowering the next year.

  7. PARAMETER EVALUATION AND MODEL VALIDATION OF OZONE EXPOSURE ASSESSMENT USING HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    Science.gov (United States)

    To examine factors influencing long-term ozone exposures by children living in urban communities, we analyzed longitudinal data on personal, indoor, and outdoor ozone concentrations as well as related housing and other questionnaire information collected in the one-year-long Harv...

  8. Prolonged ozone exposure in an allergic airway disease model: Adaptation of airway responsiveness and airway remodeling

    Directory of Open Access Journals (Sweden)

    Park Chang-Soo

    2006-02-01

    Full Text Available Abstract Background Short-term exposure to high concentrations of ozone has been shown to increase airway hyper-responsiveness (AHR. Because the changes in AHR and airway inflammation and structure after chronic ozone exposure need to be determined, the goal of this study was to investigate these effects in a murine model of allergic airway disease. Methods We exposed BALB/c mice to 2 ppm ozone for 4, 8, and 12 weeks. We measured the enhanced pause (Penh to methacholine and performed cell differentials in bronchoalveolar lavage fluid. We quantified the levels of IL-4 and IFN-γ in the supernatants of the bronchoalveolar lavage fluids using enzyme immunoassays, and examined the airway architecture under light and electron microscopy. Results The groups exposed to ozone for 4, 8, and 12 weeks demonstrated decreased Penh at methacholine concentrations of 12.5, 25, and 50 mg/ml, with a dose-response curve to the right of that for the filtered-air group. Neutrophils and eosinophils increased in the group exposed to ozone for 4 weeks compared to those in the filtered-air group. The ratio of IL-4 to INF-γ increased significantly after exposure to ozone for 8 and 12 weeks compared to the ratio for the filtered-air group. The numbers of goblet cells, myofibroblasts, and smooth muscle cells showed time-dependent increases in lung tissue sections from the groups exposed to ozone for 4, 8, and 12 weeks. Conclusion These findings demonstrate that the increase in AHR associated with the allergic airway does not persist during chronic ozone exposure, indicating that airway remodeling and adaptation following repeated exposure to air pollutants can provide protection against AHR.

  9. Exposure-Relevant Ozone Chemistry in Occupied Spaces

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Beverly Kaye [Univ. of California, Berkeley, CA (United States)

    2009-04-01

    Ozone, an ambient pollutant, is transformed into other airborne pollutants in the indoor environment. In this dissertation, the type and amount of byproducts that result from ozone reactions with common indoor surfaces, surface residues, and vapors were determined, pollutant concentrations were related to occupant exposure, and frameworks were developed to predict byproduct concentrations under various indoor conditions. In Chapter 2, an analysis is presented of secondary organic aerosol formation from the reaction of ozone with gas-phase, terpene-containing consumer products in small chamber experiments under conditions relevant for residential and commercial buildings. The full particle size distribution was continuously monitored, and ultrafine and fine particle concentrations were in the range of 10 to>300 mu g m-3. Particle nucleation and growth dynamics were characterized.Chapter 3 presents an investigation of ozone reactions with aircraft cabin surfaces including carpet, seat fabric, plastics, and laundered and worn clothing fabric. Small chamber experiments were used to determine ozone deposition velocities, ozone reaction probabilities, byproduct emission rates, and byproduct yields for each surface category. The most commonly detected byproducts included C1?C10 saturated aldehydes and skin oil oxidation products. For all materials, emission rates were higher with ozone than without. Experimental results were used to predict byproduct exposure in the cabin and compare to other environments. Byproduct levels are predicted to be similar to ozone levels in the cabin, which have been found to be tens to low hundreds of ppb in the absence of an ozone converter. In Chapter 4, a model is presented that predicts ozone uptake by and byproduct emission from residual chemicals on surfaces. The effects of input parameters (residue surface concentration, ozone concentration, reactivity of the residue and the surface, near-surface airflow conditions, and

  10. Ozone exposure increases respiratory epithelial permeability in humans

    International Nuclear Information System (INIS)

    Kehrl, H.R.; Vincent, L.M.; Kowalsky, R.J.; Horstman, D.H.; O'Neil, J.J.; McCartney, W.H.; Bromberg, P.A.

    1987-01-01

    Ozone is a respiratory irritant that has been shown to cause an increase in the permeability of the respiratory epithelium in animals. We used inhaled aerosolized /sup 99m/Tc-labeled diethylene triamine pentacetic acid (/sup 99m/Tc-DTPA) to investigate whether human respiratory epithelial permeability is similarly affected by exposure to ozone. In a randomized, crossover double-blinded study, 8 healthy, nonsmoking young men were exposed for 2 h to purified air and 0.4 ppm ozone while performing intermittent high intensity treadmill exercise (minute ventilation = 66.8 L/min). SRaw and FVC were measured before and at the end of exposures. Seventy-five minutes after the exposures, the pulmonary clearance of /sup 99m/Tc-DTPA was measured by sequential posterior lung imaging with a computer-assisted gamma camera. Ozone exposure caused respiratory symptoms in all 8 subjects and was associated with a 14 +/- 2.8% (mean +/- SEM) decrement in FVC (p less than 0.001) and a 71 +/- 22% increase in SRaw (p = 0.04). Compared with the air exposure day, 7 of the 8 subjects showed increased /sup 99m/Tc-DTPA clearance after the ozone exposure, with the mean value increasing from 0.59 +/- 0.08 to 1.75 +/- 0.43%/min (p = 0.03). These data show that ozone exposure sufficient to produce decrements in the pulmonary function of human subjects also causes an increase in /sup 99m/Tc-DTPA clearance

  11. Impact of enhanced ozone deposition and halogen chemistry on tropospheric ozone over the Northern Hemisphere

    Science.gov (United States)

    Fate of ozone in marine environments has been receiving increased attention due to the tightening of ambient air quality standards. The role of deposition and halogen chemistry is examined through incorporation of an enhanced ozone deposition algorithm and inclusion of halogen ch...

  12. Differential expression of ozone-induced gene during exposures to ...

    African Journals Online (AJOL)

    Differential expression of ozone-induced gene during exposures to salt stress in Polygonum sibiricum Laxm leaves, stem and underground stem. ... PcOZI-1 mRNA in untreated plants was detected at low levels in underground stem, leaves and at higher levels in stem. PcOZI-1 mRNA accumulation was transiently induced ...

  13. Incorporation of glucose carbons into rat lung lipids after exposure to 0.6 ppm ozone

    International Nuclear Information System (INIS)

    Bassett, D.J.; Rabinowitz, J.L.

    1985-01-01

    Continuous exposure to low concentrations of ozone has previously been associated with proliferation of lung alveolar type II epithelial cells. In this study, 14 C incorporation into tissue lipids was determined in isolated rat lungs by perfusion with [U- 14 C]glucose, at a time of maximal hyperplasia brought about by 3 days continuous exposure to 0.6 ppm ozone. Ozone exposed lungs exhibited increased rates of glycolytic energy production, indicated by an 89% increase in 3 H 2 O generation on perfusion with [5-3H]glucose. Ozone exposure resulted in enhanced 14 C incorporations into glyceride-glycerol and fatty acid moieties of lung lipids of 95 and 180%, respectively, with a greater proportion of label being recovered in shorter chain fatty acids. Although increased labeling was observed in both neutral and phospholipids, the pattern of 14 C recovery suggested a relative increased glucose carbon incorporation into lung free fatty acids, phosphatidic acid, and such membrane associated lipids as phosphatidylinositol and those containing sphingosine. These results are consistent with the needs of a dividing cell population for enhanced energy production and synthesis of new lipids

  14. CORRELATION BETWEEN OZONE EXPOSURE AND VISIBLE FOLIAR INJURY IN PONDEROSA AND JEFFREY PINES. (R825433)

    Science.gov (United States)

    Ozone exposure was related to ozone-induced visible foliar injury in ponderosa and Jeffrey pines growing on the western slopes of the Sierra Nevada Mountains of California. Measurements of ozone exposure, chlorotic mottle and fascicle retention were collected during the years ...

  15. Ozone exposure, uptake, and response of different-sized black cherry trees

    Science.gov (United States)

    Todd S. Frederickson; John M. Skelly; Kim C. Steiner; Thomas E. Kolb

    1996-01-01

    Differences in exposure, uptake and relative sensitivity to ozone between seedling, sapling, and canopy black cherry (Prunus serotina Ehrh.) trees were characterized during two growing seasons in north central Pennsylvania. Open-grown trees of all sizes received a similar amount of ozone exposure. Seedlings had greater foliar ozone injury, expressed...

  16. Attenuated response to repeated daily ozone exposures in asthmatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Gong, H. Jr.; Linn, W.S. [Rancho Low Amigos Medical Center, Downey, CA (United States); McManus, M.S. [Univ. of California, Los Angeles, CA (United States)

    1997-01-01

    The development of attenuated response ({open_quotes}tolerance{close_quotes}) to daily ozone (O{sub 3}) exposures in the laboratory is well established in healthy adult volunteers. However, the capability of asthmatics to develop tolerance during multiday ozone exposures in unclear. We exposed 10 adult volunteers with mild asthma to 0.4 ppm O{sub 3} in filtered air for 3 h/d on 5 consecutive d. Two similar filtered-air exposures during the preceding week served as controls. Follow-up O{sub 3} exposures were performed 4 and 7 d after the most recent consecutive exposure. All exposures were performed in an environmental chamber at 31 {degrees}C and 35% relative humidity. The subjects performed moderate exercise (mean ventilation rate of 32 l/min) for 15 min of each half-hour. Responses were measured with spirometry and symptom evaluations before and after each exposure, and a bronchial reactivity test (methacholine challenge) was conducted after each exposure. All response measurements showed clinically and statistically significant day-to-day variation. Symptom and forced-expiratory-volume-in-1-s responses were similarly large on the 1st and 2nd O{sub 3} exposure days, after which they diminished progressively, approaching filtered air response levels by the 5th consecutive O{sub 3} day. This tolerance was partially lost 4 and 7 d later. Bronchial reactivity peaked after the first O{sub 3} exposure and remained somewhat elevated after all subsequent O{sub 3} exposures, relative to its control level following filtered-air exposures. Individual responses varied widely; more severe initial responses to O{sub 3} predicted less rapid attenuation. We concluded that asthmatics can develop tolerance to frequent high-level O{sub 3} exposures in much the same manner as normal subjects, although the process may be slower and less fully effective in asthmatics. 27 refs., 3 figs., 4 tabs.

  17. AN EVALUATION OF OZONE EXPOSURE METRICS FOR A SEASONALLY DROUGHT STRESSED PONDEROSA PINE ECOSYSTEM. (R826601)

    Science.gov (United States)

    Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at ...

  18. PLASMA AND LUNG MACROPHAGE CAROTENOID RESPONSIVENESS TO SUPPLEMENTATION AND OZONE EXPOSURE IN HUMANS

    Science.gov (United States)

    OBJECTIVE:: To examine the effect of ozone exposure and vegetable juice supplementation on plasma and lung macrophage concentrations of carotenoids. DESIGN:: A randomized trial. SETTING:: Subjects were exposed to ambient air prior to antioxidant supplementation and to ozone after...

  19. Controlled human exposure to indoor air, dust, and ozone; XDOZ

    DEFF Research Database (Denmark)

    Elholm, Grethe; Bønløkke, Jakob; Schlünssen, Vivi

    2017-01-01

    . All participants were subjected to four different exposure scenarios in the climate chamber.Exp. 1: Dust (250 – 300 µg/m3)Exp. 2: Ozone (100 ppb)Exp. 3: Dust (250 – 300 µg/m3) + ozone (100 ppb)Exp. 4: Filtered air (<20µg/m3)The exposure time was 5½ hours for each session.The health effects were...... evaluated at baseline and specific follow-up times in relation to selected respiratory and cardiovascular outcomes, such as; nasal volume, exhaled nitric oxide (FENO), spirometry (FEV1 and FVC), exhaled breath condensate (EBC), nasal lavage, blood samples, EndoPat. Questionnaires were used for assessment...

  20. Modelling of individual subject ozone exposure response kinetics.

    Science.gov (United States)

    Schelegle, Edward S; Adams, William C; Walby, William F; Marion, M Susan

    2012-06-01

    A better understanding of individual subject ozone (O(3)) exposure response kinetics will provide insight into how to improve models used in the risk assessment of ambient ozone exposure. To develop a simple two compartment exposure-response model that describes individual subject decrements in forced expiratory volume in one second (FEV(1)) induced by the acute inhalation of O(3) lasting up to 8 h. FEV(1) measurements of 220 subjects who participated in 14 previously completed studies were fit to the model using both particle swarm and nonlinear least squares optimization techniques to identify three subject-specific coefficients producing minimum "global" and local errors, respectively. Observed and predicted decrements in FEV(1) of the 220 subjects were used for validation of the model. Further validation was provided by comparing the observed O(3)-induced FEV(1) decrements in an additional eight studies with predicted values obtained using model coefficients estimated from the 220 subjects used in cross validation. Overall the individual subject measured and modeled FEV(1) decrements were highly correlated (mean R(2) of 0.69 ± 0.24). In addition, it was shown that a matrix of individual subject model coefficients can be used to predict the mean and variance of group decrements in FEV(1). This modeling approach provides insight into individual subject O(3) exposure response kinetics and provides a potential starting point for improving the risk assessment of environmental O(3) exposure.

  1. Ozone pollution and ozone biomonitoring in European cities. Part I: Ozone concentrations and cumulative exposure indices at urban and suburban sites

    DEFF Research Database (Denmark)

    Klumpp, A.; Ansel, W.; Klumpp, G.

    2006-01-01

    In the frame of a European research project on air quality in urban agglomerations, data on ozone concentrations from 23 automated urban and suburban monitoring stations in 11 cities from seven countries were analysed and evaluated. Daily and summer mean and maximum concentrations were computed...... based on hourly mean values, and cumulative ozone exposure indices (Accumulated exposure Over a Threshold of 40 ppb (AOT40), AOT20) were calculated. The diurnal profiles showed a characteristic pattern in most city centres, with minimum values in the early morning hours, a strong rise during the morning......, by contrast, maximum values were lower and diurnal variation was much smaller. Based on ozone concentrations as well as on cumulative exposure indices, a clear north-south gradient in ozone pollution, with increasing levels from northern and northwestern sites to central and southern European sites...

  2. The effect of ozone exposure on the airway response to inhaled allergens; Die Wirkung der Einatmung von Ozon auf die allergische Reaktion des Bronchialsystems

    Energy Technology Data Exchange (ETDEWEB)

    Joerres, R. [Krankenhaus Grosshansdorf (Germany). Zentrum fuer Pneumologie und Thoraxchirurgie; Nowak, D. [Krankenhaus Grosshansdorf (Germany). Zentrum fuer Pneumologie und Thoraxchirurgie; Magnussen, H. [Krankenhaus Grosshansdorf (Germany). Zentrum fuer Pneumologie und Thoraxchirurgie

    1995-06-01

    The aim of our study was to determine whether a short-term exposure to ozone enhances the bronchial response to allergens in subjects with allergic asthma, or facilitates a bronchial response in subjects with allergic rhinitis. In the first part of the study we investigated 57 subjects with mild stable asthma, 29 subjects with allergic rhinitis only and 32 healthy subjects. They were exposed to 250 ppb ozone for 3 hrs of intermittent exercise. The effects of ozone on symptoms, lung function parameters and methacholine responsiveness were no markedly different between groups. Twenty-four subjects with asthma and a proven bronchial response to an inhaled allergen, 12 subjects with allergic rhinitis and 10 healthy subjects participated in the second part of the study. In randomized order, subjects breathed 250 ppb ozone or filtered air (FA) for 3 hrs of intermittent exercise. Lung function and airway responsiveness to methacholine were determined before and after exposures, and allergen inhalation challenges were performed 3 hrs after exposures. The 5 subjects with asthma showed increased airway responsiveness to the inhaled allergen after ozone. The subjects with rhinitis showed a slight bronchial response when a high dose of allergen was inhalated after ozone exposure. The changes in lung function, methacholine and allergen responsiveness induced by ozone did not correlate with each other. Our data suggest that a short-term exposure to ozone can increase bronchial allergen responsiveness in subjects with asymptomatic to mild asthma and that this effect is not directly related to other functional changes induced by ozone. (orig./MG) [Deutsch] Unsere Untersuchung widmete sich der Frage, ob die Einatmung von Ozon das Auftreten oder die Auspraegung einer allergischen Reaktion der Atemwege beeinflussen kann. Zunaechst prueften wir 57 Probanden mit allergischem Asthma bronchiale, 29 mit allergischer Rhinitis ohne Asthma und 32 gesunde Kontrollpersonen auf die

  3. TOWARDS RELIABLE AND COST-EFFECTIVE OZONE EXPOSURE ASSESSMENT: PARAMETER EVALUATION AND MODEL VALIDATION USING THE HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    Science.gov (United States)

    Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a...

  4. Effects of ozone exposure on lung function in man: a review

    Energy Technology Data Exchange (ETDEWEB)

    Folinsbee, L J

    1981-01-01

    Ozone, an important component of photochemical smog, has a decided impact on lung function in man. In this review, the effects of zone on human lung function are discussed with particular attention to levels which are near the threshold of producing no effect. Attempts to define dose-response relationships and effects on sensitive subject populations are described. The relationship between exercise and ozone toxicity is presented in addition to the potential impact of ambient ozone exposure on athletic performance. Effects of ozone on respiratory symptoms and the interaction of ozone with other pollutants are briefly examined. Considerable attention has been directed at the phenomenon of adaptation to repeated ozone exposure and to possible mechanism of action of ozone.

  5. Evaluation of ozone emissions and exposures from consumer products and home appliances.

    Science.gov (United States)

    Zhang, Q; Jenkins, P L

    2017-03-01

    Ground-level ozone can cause serious adverse health effects and environmental impacts. This study measured ozone emissions and impacts on indoor ozone levels and associated exposures from 17 consumer products and home appliances that could emit ozone either intentionally or as a by-product of their functions. Nine products were found to emit measurable ozone, one up to 6230 ppb at a distance of 5 cm (2 inches). One use of these products increased room ozone concentrations by levels up to 106 ppb (mean, from an ozone laundry system) and personal exposure concentrations of the user by 12-424 ppb (mean). Multiple cycles of use of one fruit and vegetable washer increased personal exposure concentrations by an average of 2550 ppb, over 28 times higher than the level of the 1-h California Ambient Air Quality Standard for ozone (0.09 ppm). Ozone emission rates ranged from 1.6 mg/h for a refrigerator air purifier to 15.4 mg/h for a fruit and vegetable washer. The use of some products was estimated to contribute up to 87% of total daily exposures to ozone. The results show that the use of some products may result in potential health impacts. © 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.

  6. Does the acute pulmonary response to ozone depend on the cumulative exposure?

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    In experimental conditions, repeated ozone exposure induces adaptive phenomena that attenuate lung function and inflammatory responses. But this study did not find that lifetime cumulative exposure had a protective effect; indeed, it found the contrary. (author)

  7. Enhanced pharmaceutical removal from water in a three step bio-ozone-bio process.

    Science.gov (United States)

    de Wilt, Arnoud; van Gijn, Koen; Verhoek, Tom; Vergnes, Amber; Hoek, Mirit; Rijnaarts, Huub; Langenhoff, Alette

    2018-07-01

    Individual treatment processes like biological treatment or ozonation have their limitations for the removal of pharmaceuticals from secondary clarified effluents with high organic matter concentrations (i.e. 17 mg TOC/L). These limitations can be overcome by combining these two processes for a cost-effective pharmaceutical removal. A three-step biological-ozone-biological (BO 3 B) treatment process was therefore designed for the enhanced pharmaceutical removal from wastewater effluent. The first biological step removed 38% of ozone scavenging TOC, thus proportionally reducing the absolute ozone input for the subsequent ozonation. Complementariness between biological and ozone treatment, i.e. targeting different pharmaceuticals, resulted in cost-effective pharmaceutical removal by the overall BO 3 B process. At a low ozone dose of 0.2 g O 3 /g TOC and an HRT of 1.46 h in the biological reactors, the removal of 8 out of 9 pharmaceuticals exceeded 85%, except for metoprolol (60%). Testing various ozone doses and HRTs revealed that pharmaceuticals were ineffectively removed at 0.1 g O3/g TOC and an HRT of 0.3 h. At HRTs of 0.47 and 1.46 h easily and moderately biodegradable pharmaceuticals such as caffeine, gemfibrozil, ibuprofen, naproxen and sulfamethoxazole were over 95% removed by biological treatment. The biorecalcitrant carbamazepine was completely ozonated at a dose of 0.4 g O 3 /g TOC. Ozonation products are likely biodegraded in the last biological reactor as a 17% TOC removal was found. No appreciable acute toxicity towards D. magna, P. subcapitata and V. fischeri was found after exposure to the influents and effluents of the individual BO 3 B reactors. The BO 3 B process is estimated to increase the yearly wastewater treatment tariff per population equivalent in the Netherlands by less than 10%. Overall, the BO 3 B process is a cost-effective treatment process for the removal of pharmaceuticals from secondary clarified effluents. Copyright

  8. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong; Wang, Qunhui; Zhang, Tao; Shi, Zhining; Tian, Yanli; Shi, Shanshan; Smale, Nicholas; Wang, Juan

    2015-01-01

    zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic

  9. Serum lipid and lipoprotein concentrations following exposure to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, W J; Adamson, G L; Lindgren, F T; Schooley, J.C.

    1984-07-01

    The effects of exposure to ozone (O/sub 3/) on concentrations of serum lipids and lipoproteins were investigated. Male and female guinea pigs were exposed to O/sub 3/ at 1 ppm for two weeks. Serum concentrations of cholesterol, triglycerides, low density (LDL) and very low density (VLDL) lipoproteins were elevated after O/sub 3/ exposure, particularly in males. During O/sub 3/ exposure the food intake per day decreased (for a constant body weight), suggesting that metabolic rate and possibly basal metabolic rate was lower. Lung wet weights increased during O/sub 3/ exposure by 87% for males and 45% for females. When individual lung weight/body weight ratios were correlated with cholesterol and LDL values from the same animal, a high correlation is found for males (r . 0.81, P less than 0.05), suggesting that there may be a relationship between lipoprotein elevations and lung damage for males. Because elevated concentrations of lipids and lipoproteins in humans increase the risk of coronary heart disease (CHD), the lipoprotein results suggest that an epidemiological study of the incidence of CHD with metropolitan O/sub 3/ levels may be warranted.

  10. Systemic metabolic derangement, pulmonary effects, and insulin insufficiency following subchronic ozone exposure in rats

    International Nuclear Information System (INIS)

    Miller, Desinia B.; Snow, Samantha J.; Henriquez, Andres; Schladweiler, Mette C.; Ledbetter, Allen D.; Richards, Judy E.; Andrews, Debora L.; Kodavanti, Urmila P.

    2016-01-01

    Acute ozone exposure induces a classical stress response with elevated circulating stress hormones along with changes in glucose, protein and lipid metabolism in rats, with similar alterations in ozone-exposed humans. These stress-mediated changes over time have been linked to insulin resistance. We hypothesized that acute ozone-induced stress response and metabolic impairment would persist during subchronic episodic exposure and induce peripheral insulin resistance. Male Wistar Kyoto rats were exposed to air or 0.25 ppm or 1.00 ppm ozone, 5 h/day, 3 consecutive days/week (wk) for 13 wks. Pulmonary, metabolic, insulin signaling and stress endpoints were determined immediately after 13 wk or following a 1 wk recovery period (13 wk + 1 wk recovery). We show that episodic ozone exposure is associated with persistent pulmonary injury and inflammation, fasting hyperglycemia, glucose intolerance, as well as, elevated circulating adrenaline and cholesterol when measured at 13 wk, however, these responses were largely reversible following a 1 wk recovery. Moreover, the increases noted acutely after ozone exposure in non-esterified fatty acids and branched chain amino acid levels were not apparent following a subchronic exposure. Neither peripheral or tissue specific insulin resistance nor increased hepatic gluconeogenesis were present after subchronic ozone exposure. Instead, long-term ozone exposure lowered circulating insulin and severely impaired glucose-stimulated beta-cell insulin secretion. Thus, our findings in young-adult rats provide potential insights into epidemiological studies that show a positive association between ozone exposures and type 1 diabetes. Ozone-induced beta-cell dysfunction may secondarily contribute to other tissue-specific metabolic alterations following chronic exposure due to impaired regulation of glucose, lipid, and protein metabolism. - Highlights: • Subchronic episodic ozone exposure caused pulmonary and metabolic effects. • These

  11. Systemic metabolic derangement, pulmonary effects, and insulin insufficiency following subchronic ozone exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Desinia B. [Curriculum in Toxicology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Snow, Samantha J. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Henriquez, Andres [Curriculum in Toxicology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina (United States); Schladweiler, Mette C.; Ledbetter, Allen D.; Richards, Judy E.; Andrews, Debora L. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Kodavanti, Urmila P., E-mail: kodavanti.urmila@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States)

    2016-09-01

    Acute ozone exposure induces a classical stress response with elevated circulating stress hormones along with changes in glucose, protein and lipid metabolism in rats, with similar alterations in ozone-exposed humans. These stress-mediated changes over time have been linked to insulin resistance. We hypothesized that acute ozone-induced stress response and metabolic impairment would persist during subchronic episodic exposure and induce peripheral insulin resistance. Male Wistar Kyoto rats were exposed to air or 0.25 ppm or 1.00 ppm ozone, 5 h/day, 3 consecutive days/week (wk) for 13 wks. Pulmonary, metabolic, insulin signaling and stress endpoints were determined immediately after 13 wk or following a 1 wk recovery period (13 wk + 1 wk recovery). We show that episodic ozone exposure is associated with persistent pulmonary injury and inflammation, fasting hyperglycemia, glucose intolerance, as well as, elevated circulating adrenaline and cholesterol when measured at 13 wk, however, these responses were largely reversible following a 1 wk recovery. Moreover, the increases noted acutely after ozone exposure in non-esterified fatty acids and branched chain amino acid levels were not apparent following a subchronic exposure. Neither peripheral or tissue specific insulin resistance nor increased hepatic gluconeogenesis were present after subchronic ozone exposure. Instead, long-term ozone exposure lowered circulating insulin and severely impaired glucose-stimulated beta-cell insulin secretion. Thus, our findings in young-adult rats provide potential insights into epidemiological studies that show a positive association between ozone exposures and type 1 diabetes. Ozone-induced beta-cell dysfunction may secondarily contribute to other tissue-specific metabolic alterations following chronic exposure due to impaired regulation of glucose, lipid, and protein metabolism. - Highlights: • Subchronic episodic ozone exposure caused pulmonary and metabolic effects. • These

  12. Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.

    Directory of Open Access Journals (Sweden)

    Jennifer B Landesmann

    Full Text Available Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb. We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.

  13. Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.

    Science.gov (United States)

    Landesmann, Jennifer B; Gundel, Pedro E; Martínez-Ghersa, M Alejandra; Ghersa, Claudio M

    2013-01-01

    Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.

  14. Ozone exposure and stomatal sluggishness in different plant physiognomic classes

    Energy Technology Data Exchange (ETDEWEB)

    Paoletti, Elena, E-mail: e.paoletti@ipp.cnr.i [IPP-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy); Grulke, Nancy E. [US Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)

    2010-08-15

    Gas exchange responses to static and variable light were tested in three species: snap bean (Phaseolus vulgaris, two cultivars), California black oak (Quercus kelloggii), and blue oak (Q. douglasii). The effects of 1-month (snap beans) and 2-month (oaks) O{sub 3} (ozone) exposure (70 ppb over 8 h per day in open-top chambers) were investigated. A delay in stomatal responses (i.e., 'sluggish' responses) to variable light was found to be both an effect of O{sub 3} exposure and a reason for increased O{sub 3} sensitivity in snap bean cultivars, as it implied higher O{sub 3} uptake during times of disequilibrium. Sluggishness increased the time to open (thus limiting CO{sub 2} uptake) and close stomata (thus increasing transpirational water loss) after abrupt changes in light level. Similar responses were shown by snap beans and oaks, suggesting that O{sub 3}-induced stomatal sluggishness is a common trait among different plant physiognomic classes. - Sluggish stomatal responses are suggested to be both an effect of O{sub 3} exposure and a reason of increased O{sub 3} sensitivity in plants.

  15. Enhancement of bromate formation by pH depression during ozonation of bromide-containing water in the presence of hydroxylamine.

    Science.gov (United States)

    Yang, Jingxin; Li, Ji; Dong, Wenyi; Ma, Jun; Yang, Yi; Li, Jiayin; Yang, Zhichao; Zhang, Xiaolei; Gu, Jia; Xie, Wanying; Cang, Yan

    2017-02-01

    This work investigated the fate of bromate formation during ozonation in the presence of hydroxylamine (HA). Results indicated that pH depression, as a commonly feasible control strategy for bromate formation during ozonation, unexpectedly enhanced the bromate formation during ozonation in the presence of HA. A dramatically high level of bromate was observed at acidic pH in the ozone/HA process. The scavenging experiments demonstrated the essential role of OH produced in the reaction of ozone with HA in bromate formation. In the process, OH mainly oxidizes bromide to Br, which is further oxidized by ozone and eventually converts to bromate. Further investigations suggested that the unexpected enhancement on bromate formation by pH depression can be mainly ascribed to the pH-dependent ozone decay, OH exposures and formation rate of Br. As pH decreased from 7 to 5, the reduced OH scavenging capacity of HA led to higher OH exposures, which contributed to the enhancement of bromate formation. As pH decreased from 5 to 3, the enhanced formation rate of Br largely augmented the formation of bromate. In addition, the ozone decay slowed down by pH depression provided more available ozone for the oxidation of the formed Br to bromate. The enhanced effect of pH depression on bromate formation was still observed in the real water samples in the ozone/HA process. Accordingly, pH depression might be avoided to control the bromate formation during ozonation in the presence of HA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Hypoxia-induced pulmonary arterial hypertension augments lung injury and airway reactivity caused by ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Zychowski, Katherine E.; Lucas, Selita N.; Sanchez, Bethany; Herbert, Guy; Campen, Matthew J., E-mail: mcampen@salud.unm.edu

    2016-08-15

    Ozone (O{sub 3})-related cardiorespiratory effects are a growing public health concern. Ground level O{sub 3} can exacerbate pre-existing respiratory conditions; however, research regarding therapeutic interventions to reduce O{sub 3}-induced lung injury is limited. In patients with chronic obstructive pulmonary disease, hypoxia-associated pulmonary hypertension (HPH) is a frequent comorbidity that is difficult to treat clinically, yet associated with increased mortality and frequency of exacerbations. In this study, we hypothesized that established HPH would confer vulnerability to acute O{sub 3} pulmonary toxicity. Additionally, we tested whether improvement of pulmonary endothelial barrier integrity via rho-kinase inhibition could mitigate pulmonary inflammation and injury. To determine if O{sub 3} exacerbated HPH, male C57BL/6 mice were subject to either 3 weeks continuous normoxia (20.9% O{sub 2}) or hypoxia (10.0% O{sub 2}), followed by a 4-h exposure to either 1 ppm O{sub 3} or filtered air (FA). As an additional experimental intervention fasudil (20 mg/kg) was administered intraperitoneally prior to and after O{sub 3} exposures. As expected, hypoxia significantly increased right ventricular pressure and hypertrophy. O{sub 3} exposure in normoxic mice caused lung inflammation but not injury, as indicated by increased cellularity and edema in the lung. However, in hypoxic mice, O{sub 3} exposure led to increased inflammation and edema, along with a profound increase in airway hyperresponsiveness to methacholine. Fasudil administration resulted in reduced O{sub 3}-induced lung injury via the enhancement of pulmonary endothelial barrier integrity. These results indicate that increased pulmonary vascular pressure may enhance lung injury, inflammation and edema when exposed to pollutants, and that enhancement of pulmonary endothelial barrier integrity may alleviate such vulnerability. - Highlights: • Environmental exposures can exacerbate chronic obstructive

  17. Hypoxia-induced pulmonary arterial hypertension augments lung injury and airway reactivity caused by ozone exposure

    International Nuclear Information System (INIS)

    Zychowski, Katherine E.; Lucas, Selita N.; Sanchez, Bethany; Herbert, Guy; Campen, Matthew J.

    2016-01-01

    Ozone (O 3 )-related cardiorespiratory effects are a growing public health concern. Ground level O 3 can exacerbate pre-existing respiratory conditions; however, research regarding therapeutic interventions to reduce O 3 -induced lung injury is limited. In patients with chronic obstructive pulmonary disease, hypoxia-associated pulmonary hypertension (HPH) is a frequent comorbidity that is difficult to treat clinically, yet associated with increased mortality and frequency of exacerbations. In this study, we hypothesized that established HPH would confer vulnerability to acute O 3 pulmonary toxicity. Additionally, we tested whether improvement of pulmonary endothelial barrier integrity via rho-kinase inhibition could mitigate pulmonary inflammation and injury. To determine if O 3 exacerbated HPH, male C57BL/6 mice were subject to either 3 weeks continuous normoxia (20.9% O 2 ) or hypoxia (10.0% O 2 ), followed by a 4-h exposure to either 1 ppm O 3 or filtered air (FA). As an additional experimental intervention fasudil (20 mg/kg) was administered intraperitoneally prior to and after O 3 exposures. As expected, hypoxia significantly increased right ventricular pressure and hypertrophy. O 3 exposure in normoxic mice caused lung inflammation but not injury, as indicated by increased cellularity and edema in the lung. However, in hypoxic mice, O 3 exposure led to increased inflammation and edema, along with a profound increase in airway hyperresponsiveness to methacholine. Fasudil administration resulted in reduced O 3 -induced lung injury via the enhancement of pulmonary endothelial barrier integrity. These results indicate that increased pulmonary vascular pressure may enhance lung injury, inflammation and edema when exposed to pollutants, and that enhancement of pulmonary endothelial barrier integrity may alleviate such vulnerability. - Highlights: • Environmental exposures can exacerbate chronic obstructive pulmonary disease (COPD). • It is unknown if comorbid

  18. Sampling Ozone Exposure of Canadian Forests at Different Scales: Some Case Studies

    Directory of Open Access Journals (Sweden)

    R.M. Cox

    2001-01-01

    Full Text Available The use of passive samplers in extensive monitoring, such as that used in national forest health monitoring plots, indicates that these devices are able to determine both spatial and temporal differences in ozone exposure of the plots. This allows for categorisation of the plots and the potential for cause-effect analysis of certain forest health responses. Forest exposure along a gradient of air pollution deposition demonstrates large variation in accumulated exposures. The efficacy of using passive samplers for in situ monitoring of forest canopy exposure was also demonstrated. The sampler data produced weak relationships with ozone values from the nearest �continuous� monitor, even though data from colocated samplers showed strong relationships. This spatial variation and the apparent effect of elevation on ozone exposure demonstrate the importance of topography and tree canopy characteristics in plant exposure on a regional scale. In addition, passive sampling may identify the effects of local pollutant gases, such as NO, which may scavenge ozone locally only to increase the production of this secondary pollutant downwind, as atmospheric reactions redress the equilibrium between concentrations of this precursor and those of the generated ozone. The use of passive samplers at the stand level is able to resolve vertical profiles within the stand and edge effects that are important in exposure of understorey and ground flora. Recent case studies using passive samplers to determine forest exposure to ozone indicate a great potential for the development of spatial models on a regional, landscape, and stand level scale.

  19. Effects of ozone exposures on epicuticular wax of ponderosa pine needles

    International Nuclear Information System (INIS)

    Bytnerowicz, A.; Turunen, M.

    1994-01-01

    Two-year-old ponderosa pine (Pinus ponderosa L.) seedlings were exposed during the 1989 and 1990 growing seasons to ozone in open-top chambers placed in a forested location at Shirley Meadow, Greenhorn Mountain Range, Sierra Nevada. The ozone treatments were as follows: charcoal-filtered air (CF); charcoal-filtered air with addition of ambient concentrations of ozone (CF + O 3 ); and charcoal-filtered air with addition of doubled concentrations of ozone (CF + 2 x O 3 ). Ozone effects on ponderosa pine seedlings progressed and accumulated over two seasons of exposure. Throughout the first season, increased visible injury and accelerated senescence of the foliage were noted. Subsequently, during the second season of ozone exposure, various physiological and biochemical changes in the foliage took place. All these changes led to reduced growth and biomass of the seedlings. Epistomatal waxes of needles from the CA + 2 x O 3 treatment had an occluded appearance. This phenomenon may be caused by earlier phenological development of needles from the high-ozone treatments and disturbed development and synthesis of waxes. It may also be caused by chemical degradation of waxes by exposures to high ozone concentrations. (orig.)

  20. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Science.gov (United States)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  1. Ozone Exposure Increases Circulating Stress Hormones and Lipid Metabolites in Humans

    Science.gov (United States)

    RATIONALE: Air pollution has been associated with increased prevalence of type 2 diabetes; however, the mechanisms remain unknown. We have shown that acute ozone exposure in rats induces release of stress hormones, hyperglycemia, leptinemia, and gluoose intolerance that are assoc...

  2. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong

    2015-02-02

    This work investigated microbubble-ozonation for the treatment of a refractory wet-spun acrylic fiber wastewater in comparison to macrobubble-ozonation. CODcr, NH3-N, and UV254 of the wastewater were removed by 42%, 21%, and 42%, respectively in the microbubble-ozonation, being 25%, 9%, and 35% higher than the removal rates achieved by macrobubble-ozonation at the same ozone dose. The microbubbles (with average diameter of 45μm) had a high concentration of 3.9×105 counts/mL at a gas flow rate of 0.5L/min. The gas holdup, total ozone mass-transfer coefficient, and average ozone utilization efficiency in the microbubble-ozonation were 6.6, 2.2, and 1.5 times higher than those of the macrobubble-ozonation. Greater generation of hydroxyl radicals and a higher zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic compounds, and the many other bio-refractory organic compounds in the wastewater. Microbubble-ozonation can thus be a more effective treatment process than traditional macrobubble-ozonation for refractory wastewater produced by the acrylic fiber manufacturing industry.

  3. Observation of enhanced ozone in an electrically active storm over Socorro, NM: Implications for ozone production from corona discharges

    Science.gov (United States)

    Minschwaner, K.; Kalnajs, L. E.; Dubey, M. K.; Avallone, L. M.; Sawaengphokai, P. C.; Edens, H. E.; Winn, W. P.

    2008-09-01

    Enhancements in ozone were observed between about 3 and 10 km altitude within an electrically active storm in central New Mexico. Measurements from satellite sensors and ground-based radar show cloud top pressures between 300 and 150 mb in the vicinity of an ozonesonde launched from Socorro, NM, and heavy precipitation with radar reflectivities exceeding 50 dBZ. Data from a lightning mapping array and a surface electric field mill show a large amount of electrical activity within this thunderstorm. The observed ozone enhancements are large (50% above the mean) and could have resulted from a number of possible processes, including the advection of polluted air from the urban environments of El Paso and Juarez, photochemical production by lightning-generated NOx from aged thunderstorm outflow, downward mixing of stratospheric air, or local production from within the thunderstorm. We find that a large fraction of the ozone enhancement is consistent with local production from corona discharges, either from cloud particles or by corona associated with lightning. The implied global source of ozone from thunderstorm corona discharge is estimated to be 110 Tg O3 a-1 with a range between 40 and 180 Tg O3 a-1. This value is about 21% as large as the estimated ozone production rate from lightning NOx, and about 3% as large as the total chemical production rate of tropospheric ozone. Thus while the estimated corona-induced production of ozone may be significant on local scales, it is unlikely to be as important to the global ozone budget as other sources.

  4. Enhanced effect of suction-cavitation on the ozonation of phenol

    International Nuclear Information System (INIS)

    Wu Zhilin; Franke, Marcus; Ondruschka, Bernd; Zhang, Yongchun; Ren Yanze; Braeutigam, Patrick; Wang, Weimin

    2011-01-01

    800 mL of 1.0 mM phenol-containing aqueous solution was circulated at 20 ° C for 30 min in a suction-reactor, while 3.2 mg min -1 ozone was introduced into the solution under the suction orifice. The removal rates of phenol vary polynomially with the orifice diameter as well as the suction pressure. The rate constant for the zero-order kinetics achieves the highest value at -0.070 MPa by using 5 mm orifice. Although the suction-cavitation alone cannot remove phenol in 30 min, it can considerably enhance the ozonation of phenol. The rate constants for the zero-order kinetics by the simple ozonation and the combined method are 0.018 and 0.028 min -1 , respectively. Furthermore, no ozone was observed in the tail gas during the first 15 min for the ozonation in the suction reactor, and then the concentration of unreacted ozone slowly increased, indicating that the utilization rate of ozone is significantly improved by the suction-cavitation. The increasing input concentration of ozone obviously accelerates the ozonation of phenol, but the total required quantities of ozone are very close by various ozone input concentrations to reach the same degradation rate, indicating the ozonation assisted by the suction-cavitation can be considered as a quantitative reaction.

  5. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    Directory of Open Access Journals (Sweden)

    Matthew J Kesic

    Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

  6. Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing.

    Science.gov (United States)

    Zhao, Hui; Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

    2018-03-29

    Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m³, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00-4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.

  7. Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

    Science.gov (United States)

    Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

    2018-01-01

    Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively. PMID:29596366

  8. Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2018-03-01

    Full Text Available Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.

  9. Chloroplastic responses of ponderosa pine (Pinus ponderosa) seedlings to ozone exposure.

    Science.gov (United States)

    Anderson, Paul D; Palmer, Brent; Houpis, James L J; Smith, Mary K; Pushnik, James C

    2003-06-01

    Integrity of chloroplast membranes is essential to photosynthesis. Loss of thylakoid membrane integrity has been proposed as a consequence of ozone (O(3)) exposure and therefore may be a mechanistic basis for decreased photosynthetic rates commonly associated with ozone exposure. To investigate this hypothesis, Pinus ponderosa seedlings were exposed to ambient air or ozone concentrations maintained at 0.15 or 0.30 microliter l(-1) for 10 h day(-1) for 51 days during their second growing season. Over the course of the study, foliage samples were periodically collected for thylakoid membrane, chlorophyll and protein analyses. Additionally, gas-exchange measurements were made in conjunction with foliage sampling to verify that observed chloroplastic responses were associated with ozone-induced changes in photosynthesis. Needles exposed to elevated ozone exhibited decreases in chlorophyll a and b content. The decreases were dependent on the duration and intensity of ozone exposure. When based on equal amounts of chlorophyll, ozone-exposed sample tissue exhibited an increase in total protein. When based on equal amounts of protein, ozone-exposed samples exhibited an increase in 37 kDa proteins, possibly consisting of breakdown products, and a possible decrease in 68 kDa proteins, Rubisco small subunit. There was also a change in the ratio of Photosystem I protein complexes CPI and CPII that may have contributed to decreased photosynthesis. Net photosynthetic rates were decreased in the high ozone treatment suggesting that observed structural and biochemical changes in the chloroplast were associated with alterations of the photosynthetic process.

  10. Accuracy and practicality of a portable ozone monitor for personal exposure estimates

    Science.gov (United States)

    Sagona, Jessica A.; Weisel, Clifford P.; Meng, Qingyu

    2018-02-01

    Accurate measurements of personal exposure to atmospheric pollutants such as ozone are important for understanding health risks. We tested a new personal ozone monitor (POM; 2B Technologies) for accuracy, precision, and ease of use. The POM's measurements were compared to simultaneous ozone measurements from a 2B Model 205 monitor and a ThermoScientific 49i monitor, and multiple POMs were placed side-by-side to check precision. Tests were undertaken in a controlled environmental facility, outdoors, and in a private residence. Additionally, ten volunteers wore a POM for five days and answered a questionnaire about its ease of use. The POM measured ozone accurately compared to the 49i ozone monitor, with average relative differences of less than 8%. In the controlled environment tests, the POM's ozone measurements did not change in the presence of additional atmospheric constituents with similar absorption lines to ozone, though there may have been a small decrease in precision and accuracy. Precision between POMs varied by environment (r2 = 0.98 outdoors; r2 = 0.3 to 0.9 in controlled lab conditions). Volunteers reported that the POM was reasonably comfortable to wear, although all reported that they felt that it was too noisy. Overall, the POM is a viable option for personal ozone monitoring.

  11. Seasonal differences and within-canopy variations of antioxidants in mature spruce (Picea abies) trees under elevated ozone in a free-air exposure system

    International Nuclear Information System (INIS)

    Hofer, Nora; Alexou, Maria; Heerdt, Christian; Loew, Markus; Werner, Herbert; Matyssek, Rainer; Rennenberg, Heinz; Haberer, Kristine

    2008-01-01

    The effect of free-air ozone fumigation and crown position on antioxidants were determined in old-growth spruce (Picea abies) trees in the seasonal course of two consecutive years (2003 and 2004). Levels of total ascorbate and its redox state in the apoplastic washing fluid (AWF) were increased under double ambient ozone concentrations (2 x O 3 ), whilst ascorbate concentrations in needle extracts were unchanged. Concentrations of apoplastic and symplastic ascorbate were significantly higher in 2003 compared to 2004 indicating a combined effect of the drought conditions in 2003 with enhanced ozone exposure. Elevated ozone had only weak effects on total glutathione levels in needle extracts, phloem exudates and xylem saps. Total and oxidised glutathione concentrations were higher in 2004 compared to 2003 and seemed to be more affected by enhanced ozone influx in the more humid year 2004 compared to the combined effect of elevated ozone and drought in 2003 as observed for ascorbate. - Antioxidant defence in sun and shade needles of Picea abies under free-air ozone fumigation in the seasonal course of two consecutive years

  12. Pulmonary sensitivity to ozone exposure in sedentary versus chronically trained, female rats.

    Science.gov (United States)

    Gordon, Christopher J; Phillips, Pamela M; Beasley, Tracey E; Ledbetter, A; Aydin, Cenk; Snow, Samantha J; Kodavanti, Urmila P; Johnstone, Andrew F

    2016-06-01

    Epidemiological data suggest that a sedentary lifestyle may contribute to increased susceptibility for some environmental toxicants. We developed an animal model of active versus sedentary life style by providing female Sprague-Dawley rats with continuous access to running wheels. Sedentary rats were housed in standard cages without wheels. After training for 12 wks, rats were exposed to 0, 0.25, 0.5 or 1.0 ppm ozone [O3 for 5 h/d, 1 d/wk, for 6 wk (N = 10 per group)]. Body composition (%fat, lean and fluid) was monitored noninvasively over the course of the study. Ventilatory parameters [tidal volume, minute ventilation, frequency and enhanced pause (Penh)] were assessed using whole-body plethysmography prior to O3 and 24 h after the 5th O3 exposure. Trained rats lost ∼2% body fat after 12 wk of access to running wheels. Peak wheel activity was reduced by 40% after exposure to 1.0 ppm O3. After the 5th O3 exposure, body weight and %fat were reduced in sedentary but not trained rats. Penh was significantly elevated in sedentary but not trained rats the day after exposure to 1.0 ppm O3. However, lung lavage cell counts and biomarkers of pulmonary inflammation measured 1 day after the final exposure were inconsistently affected by training. Wheel running led to marked physiological responses along with some indication of improved pulmonary recovery from O3 exposure. However, wheel running with O3 exposure may also be a detriment for some pulmonary endpoints. Overall, a sedentary lifestyle may increase susceptibility to O3, but additional studies are needed.

  13. Effects and mechanism on Kapton film under ozone exposure in a ground near space simulator

    Science.gov (United States)

    Wei, Qiang; Yang, Guimin; Liu, Gang; Jiang, Haifu; Zhang, Tingting

    2018-05-01

    The effect on aircraft materials in the near space environment is a key part of air-and-space integration research. Ozone and aerodynamic fluids are important organizational factors in the near space environment and both have significant influences on the performance of aircraft materials. In the present paper a simulated ozone environment was used to test polyimide material that was rotated at the approximate velocity of 150-250 m/s to form an aerodynamic fluid field. The goal was to evaluate the performance evolution of materials under a comprehensive environment of ozone molecular corrosion and aerodynamic fluids. The research results show that corrosion and sputtering by ozone molecules results in Kapton films exhibiting a rugged "carpet-like" morphology exhibits an increase in surface roughness. The morphology after ozone exposure led to higher surface roughness and an increase in surface optical diffuse reflection, which is expressed by the lower optical transmittance and the gradual transition from light orange to brown. The mass loss test, XPS, and FTIR analysis show that the molecular chains on the surface of the Kapton film are destroyed resulting in Csbnd C bond breaking to form small volatile molecules such as CO2 or CO, which are responsible for a linear increase in mass loss per unit area. The Csbnd N and Csbnd O structures exhibit weakening tendency under ozone exposure. The present paper explores the evaluation method for Kapton's adaptability under the ozone exposure test in the near space environment, and elucidates the corrosion mechanism and damage mode of the polyimide material under the combined action of ozone corrosion and the aerodynamic fluid. This work provides a methodology for studying materials in the near-space environment.

  14. Ozone exposure and pulmonary effects in panel and human clinical studies: Considerations for design and interpretation.

    Science.gov (United States)

    Rohr, Annette C

    2018-04-01

    A wealth of literature exists regarding the pulmonary effects of ozone, a photochemical pollutant produced by the reaction of nitrogen oxide and volatile organic precursors in the presence of sunlight. This paper focuses on epidemiological panel studies and human clinical studies of ozone exposure, and discusses issues specific to this pollutant that may influence study design and interpretation as well as other, broader considerations relevant to ozone-health research. The issues are discussed using examples drawn from the wider literature. The recent panel and clinical literature is also reviewed. Health outcomes considered include lung function, symptoms, and pulmonary inflammation. Issues discussed include adversity, reversibility, adaptation, variability in ozone exposure metric used and health outcomes evaluated, co-pollutants in panel studies, influence of temperature in panel studies, and multiple comparisons. Improvements in and standardization of panel study approaches are recommended to facilitate comparisons between studies as well as meta-analyses. Additional clinical studies at or near the current National Ambient Air Quality Standard (NAAQS) of 70 ppb are recommended, as are clinical studies in sensitive subpopulations such as asthmatics. The pulmonary health impacts of ozone exposure have been well documented using both epidemiological and chamber study designs. However, there are a number of specific methodological and related issues that should be considered when interpreting the results of these studies and planning additional research, including the standardization of exposure and health metrics to facilitate comparisons among studies.

  15. Ozone exposure affects leaf wettability and tree water balance

    NARCIS (Netherlands)

    Schreuder, M.D.J.; Hove, van L.W.A.; Brewer, C.A.

    2001-01-01

    Relatively little is known about the influences of growing-season background ozone (O3) concentrations on leaf cuticles and foliar water loss. Using fumigation chambers, leaf wettability and foliar water loss were studied in two poplar species, Populus nigra and P. euramericana, and a conifer,

  16. Impact of enhanced ozone deposition and halogen chemistry on model performance

    Science.gov (United States)

    In this study, an enhanced ozone deposition scheme due to the interaction of iodide in sea-water and atmospheric ozone and the detailed chemical reactions of organic and inorganic halogen species are incorporated into the hemispheric Community Multiscale Air Quality model. Prelim...

  17. Are Bavarian Forests (southern Germany) at risk from ground-level ozone? Assessment using exposure and flux based ozone indices

    International Nuclear Information System (INIS)

    Baumgarten, Manuela; Huber, Christian; Bueker, Patrick; Emberson, Lisa; Dietrich, Hans-Peter; Nunn, Angela J.; Heerdt, Christian; Beudert, Burkhard; Matyssek, Rainer

    2009-01-01

    Exposure and flux-based indices of O 3 risk were compared, at 19 forest locations across Bavaria in southern Germany from 2002 to 2005; leaf symptoms on mature beech trees found at these locations were also examined for O 3 injury. O 3 flux modelling was performed using continuously recorded O 3 concentrations in combination with meteorological and soil moisture data collected from Level II forest sites. O 3 measurements at nearby rural open-field sites proved appropriate as surrogates in cases where O 3 data were lacking at forest sites (with altitude-dependent average differences of about 10% between O 3 concentrations). Operational thresholds of biomass loss for both O 3 indices were exceeded at the majority of the forest locations, suggesting similar risk under long-term average climate conditions. However, exposure-based indices estimated higher O 3 risk during dry years as compared to the flux-based approach. In comparison, minor O 3 -like leaf injury symptoms were detected only at a few of the forest sites investigated. Relationships between flux-based risk thresholds and tree response need to be established for mature forest stands for validation of predicted growth reductions under the prevailing O 3 regimes. - Exposure- and flux-based ozone indices suggest Bavarian forests to be at risk from ozone; the flux-based index offers a means of incorporating stand-specific and ecological variables that influence risk.

  18. Structural and functional localization of airway effects from episodic exposure of infant monkeys to allergen and/or ozone

    International Nuclear Information System (INIS)

    Joad, Jesse P.; Kott, Kayleen S.; Bric, John M.; Peake, Janice L.; Plopper, Charles G.; Schelegle, Edward S.; Gershwin, Laurel J.; Pinkerton, Kent E.

    2006-01-01

    Both allergen and ozone exposure increase asthma symptoms and airway responsiveness in children. Little is known about how these inhalants may differentially modify airway responsiveness in large proximal as compared to small distal airways. We evaluated whether bronchi and respiratory bronchioles from infant monkeys exposed episodically to allergen and/or ozone differentially develop intrinsic hyperresponsiveness to methacholine and whether eosinophils and/or pulmonary neuroendocrine cells play a role. Infant monkeys were exposed episodically for 5 months to: (1) filtered air, (2) aerosolized house dust mite allergen, (3) ozone 0.5 ppm, or (4) house dust mite allergen + ozone. Studying the function/structure relationship of the same lung slices, we evaluated methacholine airway responsiveness and histology of bronchi and respiratory bronchioles. In bronchi, intrinsic responsiveness was increased by allergen exposure, an effect reduced by bombesin antagonist. In respiratory bronchioles, intrinsic airway responsiveness was increased by allergen + ozone exposure. Eosinophils were increased by allergen and allergen + ozone exposure in bronchi and by allergen exposure in respiratory bronchioles. In both airways, exposure to allergen + ozone resulted in fewer tissue eosinophils than did allergen exposure alone. In bronchi, but not in respiratory bronchioles, the number of eosinophils and neuroendocrine cells correlated with airway responsiveness. We conclude that episodically exposing infant monkeys to house dust mite allergen with or without ozone increased intrinsic airway responsiveness to methacholine in bronchi differently than in respiratory bronchioles. In bronchi, eosinophils and neuroendocrine cells may play a role in the development of airway hyperresponsiveness

  19. Comparative cardiopulmonary effects of particulate matter- and ozone-enhanced smog atmospheres in mice

    Science.gov (United States)

    This study was conducted to compare the cardiac effects of particulate matter (PM)-enhanced and ozone(O3)-enhanced smog atmospheres in mice. We hypothesized that O3-enhanced smog would cause greater cardiac dysfunction than PM-enhanced smog due to the higher concentrations of irr...

  20. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    Directory of Open Access Journals (Sweden)

    P. J. Nowack

    2016-03-01

    Full Text Available Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM. Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere–ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  1. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    Science.gov (United States)

    Nowack, Peer Johannes; Abraham, Nathan Luke; Braesicke, Peter; Pyle, John Adrian

    2016-03-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  2. Loblolly pine seedling growth after inoculation with plant growth-promoting rhizobacteria and ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Estes, B.L.; Enebak, S.A.; Chappelka, A.H. [Auburn Univ., Auburn, AL (United States). School of Forestry and Wildlife Sciences

    2004-07-01

    The conifer tree species with the greatest economic importance in south eastern United States plantations is Loblolly pine. Plantations require intensive fertilization, pesticide application, and irrigation. In these cases growth-promoting rhizobacteria are useful in pest control. While it was once thought that ozone in the troposphere was limited to urban areas, it is now known that it is transported far from its place of origin. Ozone is known to impact plant growth negatively. There have been no previous studies on whether growth-promoting rhizobacteria can decrease the negative effects of ozone. In this study seedlings of Loblolly pine were inoculated with either Bacillus subtilis (Ehrenberg) Cohn or Paenibacillus macerans (Schardinger) Ash. These were exposed to controlled amounts of ozone for 8-12 weeks. All plants showed decreased biomass and increased foliar damage compared to plants that were not exposed to ozone. B. subtilis inoculated plants showed less foliar damage than un-inoculated ones and root dimensions were increased. The use of growth-promoting rhizobacteria is not ready for large-scale commercial application in forestry, but this demonstration of the possible beneficial effects on ozone exposure warrants further investigation. 44 refs., 3 tabs., 2 figs.

  3. Passive monitoring techniques for evaluating atmospheric ozone and nitrogen exposure and deposition to California ecosystems

    Science.gov (United States)

    Mark E. Fenn; Andrzej Bytnerowicz; Susan L. Schilling

    2018-01-01

    Measuring the exposure of ecosystems to ecologically relevant pollutants is needed for evaluating ecosystem effects and to identify regions and resources at risk. In California, ozone (O3) and nitrogen (N) pollutants are of greatest concern for ecological effects. "Passive" monitoring methods have been developed to obtain spatially...

  4. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    International Nuclear Information System (INIS)

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population. (topical review)

  5. Pulmonary Ozone Exposure Alters Essential Metabolic Pathways involved in Glucose Homeostasis in the Liver

    Science.gov (United States)

    Pulmonary Ozone Exposure Alters Essential Metabolic Pathways involved in Glucose Homeostasis in the Liver D.B. Johnson, 1 W.O. Ward, 2 V.L. Bass, 2 M.C.J. Schladweiler, 2A.D. Ledbetter, 2 D. Andrews, and U.P. Kodavanti 2 1 Curriculum in Toxicology, UNC School of Medicine, Cha...

  6. Ozone treatment of shell eggs to preserve functional quality and enhance shelf life during storage.

    Science.gov (United States)

    Yüceer, Muhammed; Aday, Mehmet Seçkin; Caner, Cengiz

    2016-06-01

    Eggs have long been recognised as a source of high-quality proteins. Many methods exist to extend shelf life of food and one of them is ozone treatment, which is an emerging technology for disinfecting surfaces in the food industry. This study aimed to extend the shelf life of fresh eggs using gaseous ozone treatments at concentrations of 2, 4 and 6 ppm with exposure times of 2 and 5 min during storage for 6 weeks at 24 °C. The effect of the treatments on interior quality and functional properties of eggs is also reported. Ozone concentration and exposure time significantly affected the Haugh unit (HU), yolk index, albumen pH, relative whipping capacity (RWC), and albumen viscosity of eggs during the storage. Control eggs had the highest albumen pH and lowest albumen viscosity. Attributes such as albumen pH and RWC of eggs exposed to ozone treatments were better than the control samples. The measurement results showed that ozone concentration at 6 ppm and exposure time of 5 min can be applied to fresh eggs and extend shelf life up to 6 weeks at 24 °C storage period. Ozone treatments helped to maintain egg quality for a longer time. Ozone concentrations at 2 and 4 ppm showed promising results in maintaining internal quality and functional properties of fresh eggs during storage. Ozone at high concentration (6 ppm) caused a detrimental effect on eggshell quality. As a result, this study demonstrated that ozone treatments of 2, and especially 4 and 6 ppm concentration maintained eggshell quality during the storage. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. Fast Flow Cavity Enhanced Ozone Monitor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Naturally occurring in the stratosphere, ozone plays a significant role in many atmospheric reactions, cloud formation, and is the key player in shielding harmful UV...

  8. The missing piece: Valuing averting behavior for children's ozone exposures

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, Carol; Reed Johnson, F.; Van Houtven, George [Research Triangle Institute, P.O. Box 12194, Research Triangle Park, NC 27709-2194 (United States)

    2006-08-15

    Individuals can reduce their exposure to air pollution by reducing the amount of time they spend outdoors. Reducing outdoor time is an example of an averting behavior that should be measured as part of willingness to pay (WTP) for improvements in air quality. In this paper, we estimate parents' WTP to prevent restrictions on a child's outdoor time from a stated-preference (SP) conjoint survey. We combine this WTP measure with an estimate of reductions in time spent outdoors on high-ozone days from an activity-diary study to estimate this averting behavior component of WTP for reductions in ozone pollution. (author)

  9. Early life exposure to allergen and ozone results in altered development in adolescent rhesus macaque lungs

    International Nuclear Information System (INIS)

    Herring, M.J.; Putney, L.F.; St George, J.A.; Avdalovic, M.V.; Schelegle, E.S.; Miller, L.A.; Hyde, D.M.

    2015-01-01

    In rhesus macaques, previous studies have shown that episodic exposure to allergen alone or combined with ozone inhalation during the first 6 months of life results in a condition with many of the hallmarks of asthma. This exposure regimen results in altered development of the distal airways and parenchyma (Avdalovic et al., 2012). We hypothesized that the observed alterations in the lung parenchyma would be permanent following a long-term recovery in filtered air (FA) housing. Forty-eight infant rhesus macaques (30 days old) sensitized to house dust mite (HDM) were treated with two week cycles of FA, house dust mite allergen (HDMA), ozone (O 3 ) or HDMA/ozone (HDMA + O 3 ) for five months. At the end of the five months, six animals from each group were necropsied. The other six animals in each group were allowed to recover in FA for 30 more months at which time they were necropsied. Design-based stereology was used to estimate volumes of lung components, number of alveoli, size of alveoli, distribution of alveolar volumes, interalveolar capillary density. After 30 months of recovery, monkeys exposed to HDMA, in either group, had significantly more alveoli than filtered air. These alveoli also had higher capillary densities as compared with FA controls. These results indicate that early life exposure to HDMA alone or HDMA + O 3 alters the development process in the lung alveoli. - Highlights: • Abnormal lung development after postnatal exposure to ozone and allergen • This remodeling is shown as smaller, more numerous alveoli and narrower airways. • Allergen appears to have more of an effect than ozone during recovery. • These animals also have continued airway hyperresponsiveness (Moore et al. 2014)

  10. Early life exposure to allergen and ozone results in altered development in adolescent rhesus macaque lungs

    Energy Technology Data Exchange (ETDEWEB)

    Herring, M.J.; Putney, L.F.; St George, J.A. [California National Primate Research Center, Davis, CA (United States); Avdalovic, M.V. [Department of Internal Medicine, Division of Pulmonary and Critical Care, University of California, Davis, CA (United States); Schelegle, E.S.; Miller, L.A. [California National Primate Research Center, Davis, CA (United States); Hyde, D.M., E-mail: dmhyde@ucdavis.edu [California National Primate Research Center, Davis, CA (United States)

    2015-02-15

    In rhesus macaques, previous studies have shown that episodic exposure to allergen alone or combined with ozone inhalation during the first 6 months of life results in a condition with many of the hallmarks of asthma. This exposure regimen results in altered development of the distal airways and parenchyma (Avdalovic et al., 2012). We hypothesized that the observed alterations in the lung parenchyma would be permanent following a long-term recovery in filtered air (FA) housing. Forty-eight infant rhesus macaques (30 days old) sensitized to house dust mite (HDM) were treated with two week cycles of FA, house dust mite allergen (HDMA), ozone (O{sub 3}) or HDMA/ozone (HDMA + O{sub 3}) for five months. At the end of the five months, six animals from each group were necropsied. The other six animals in each group were allowed to recover in FA for 30 more months at which time they were necropsied. Design-based stereology was used to estimate volumes of lung components, number of alveoli, size of alveoli, distribution of alveolar volumes, interalveolar capillary density. After 30 months of recovery, monkeys exposed to HDMA, in either group, had significantly more alveoli than filtered air. These alveoli also had higher capillary densities as compared with FA controls. These results indicate that early life exposure to HDMA alone or HDMA + O{sub 3} alters the development process in the lung alveoli. - Highlights: • Abnormal lung development after postnatal exposure to ozone and allergen • This remodeling is shown as smaller, more numerous alveoli and narrower airways. • Allergen appears to have more of an effect than ozone during recovery. • These animals also have continued airway hyperresponsiveness (Moore et al. 2014)

  11. Ozone changes under solar geoengineering: implications for UV exposure and air quality

    Science.gov (United States)

    Nowack, P. J.; Abraham, N. L.; Braesicke, P.; Pyle, J. A.

    2015-11-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term Solar Radiation Management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks such as ozone changes under this scenario. Including the composition changes, we find large reductions in surface UV-B irradiance, with implications for vitamin D production, and increases in surface ozone concentrations, both of which could be important for human health. We highlight that both tropospheric and stratospheric ozone changes should be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  12. Environmental ozone exposure and oxidative DNA damage in adult residents of Florence, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Palli, Domenico, E-mail: d.palli@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Sera, Francesco, E-mail: f.sera@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Giovannelli, Lisa, E-mail: lisag@pharm.unifi.i [Department of Pharmacology, University of Florence, Viale G.Pieraccini 6, 50139 Florence (Italy); Masala, Giovanna, E-mail: g.masala@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Grechi, Daniele [Regional Environmental Protection Agency of Tuscany (ARPAT), Via Porpora 22, 50144 Florence (Italy); Bendinelli, Benedetta, E-mail: b.bendinelli@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Caini, Saverio, E-mail: s.caini@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Dolara, Piero, E-mail: piero.dolara@unifi.i [Department of Pharmacology, University of Florence, Viale G.Pieraccini 6, 50139 Florence (Italy); Saieva, Calogero, E-mail: c.saieva@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy)

    2009-05-15

    In 71 adults residing in Florence, Italy, enrolled in a prospective study, we investigated the correlation between individual levels of oxidative DNA damage detected by the Comet assay in circulating lymphocytes, and a specific ozone exposure score calculated in 10 different time-windows (0-5 to 0-90 days) before blood drawing, based on daily measurements provided by the local environmental monitoring system. Overall, statistically significant positive correlations between average ozone concentrations and DNA damage emerged in almost all time-windows considered; correlations were more evident among males, non-smokers, and traffic-exposed workers. Multivariate regression analyses taking into account selected individual characteristics, showed an independent effect on DNA damage of average ozone concentrations in the last 60-90 days before blood drawing. Local residents showed a divergent pattern with correlations restricted to shorter time-windows. Our results suggest that ozone concentrations at ground levels modulate oxidative DNA damage in circulating lymphocytes of residents of polluted areas. - Ozone concentrations over the 60-90 days before blood drawing correlated with DNA damage in circulating lymphocytes of adults living in the metropolitan area of Florence, Italy.

  13. Environmental ozone exposure and oxidative DNA damage in adult residents of Florence, Italy

    International Nuclear Information System (INIS)

    Palli, Domenico; Sera, Francesco; Giovannelli, Lisa; Masala, Giovanna; Grechi, Daniele; Bendinelli, Benedetta; Caini, Saverio; Dolara, Piero; Saieva, Calogero

    2009-01-01

    In 71 adults residing in Florence, Italy, enrolled in a prospective study, we investigated the correlation between individual levels of oxidative DNA damage detected by the Comet assay in circulating lymphocytes, and a specific ozone exposure score calculated in 10 different time-windows (0-5 to 0-90 days) before blood drawing, based on daily measurements provided by the local environmental monitoring system. Overall, statistically significant positive correlations between average ozone concentrations and DNA damage emerged in almost all time-windows considered; correlations were more evident among males, non-smokers, and traffic-exposed workers. Multivariate regression analyses taking into account selected individual characteristics, showed an independent effect on DNA damage of average ozone concentrations in the last 60-90 days before blood drawing. Local residents showed a divergent pattern with correlations restricted to shorter time-windows. Our results suggest that ozone concentrations at ground levels modulate oxidative DNA damage in circulating lymphocytes of residents of polluted areas. - Ozone concentrations over the 60-90 days before blood drawing correlated with DNA damage in circulating lymphocytes of adults living in the metropolitan area of Florence, Italy.

  14. A probabilistic assessment of health risks associated with short-term exposure to tropospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Whitfield, R.G; Biller, W.F.; Jusko, M.J.; Keisler, J.M.

    1996-06-01

    The work described in this report is part of a larger risk assessment sponsored by the U.S. Environmental Protection Agency. Earlier efforts developed exposure-response relationships for acute health effects among populations engaged in heavy exertion. Those efforts also developed a probabilistic national ambient air quality standards exposure model and a general methodology for integrating probabilistic exposure-response relation- ships and exposure estimates to calculate overall risk results. Recently published data make it possible to model additional health endpoints (for exposure at moderate exertion), including hospital admissions. New air quality and exposure estimates for alternative national ambient air quality standards for ozone are combined with exposure-response models to produce the risk results for hospital admissions and acute health effects. Sample results explain the methodology and introduce risk output formats.

  15. DC corona discharge ozone production enhanced by magnetic field

    Science.gov (United States)

    Pekárek, S.

    2010-01-01

    We have studied the effect of a stationary magnetic field on the production of ozone from air at atmospheric pressure by a negative corona discharge in a cylindrical electrode configuration. We used a stainless steel hollow needle placed at the axis of the cylindrical discharge chamber as a cathode. The outer wall of the cylinder was used as an anode. The vector of magnetic induction was perpendicular to the vector of current density. We found that: (a) the magnetic field extends the current voltage range of the discharge; (b) for the discharge in the Trichel pulses regime and in the pulseless glow regime, the magnetic field has no substantial effect on the discharge voltage or on the concentration of ozone that is produced; (c) for the discharge in the filamentary streamer regime for a particular current, the magnetic field increases the discharge voltage and consequently an approximately 30% higher ozone concentration can be obtained; (d) the magnetic field does not substantially increase the maximum ozone production yield. A major advantage of using a magnetic field is that the increase in ozone concentration produced by the discharge can be obtained without additional energy requirements.

  16. Growth response of Pinus ponderosa seedlings and mature tree branches to acid rain and ozone exposure

    International Nuclear Information System (INIS)

    Anderson, P.D.; Houpis, J.L.J.; Helms, J.A.

    1994-10-01

    Forests of the central and southern Sierra Nevada in California have been subjected to chronic damage by ozone and other atmospheric pollutants for the past several decades. Until recently, pollutant exposure of northern Sierra Nevada forests has been mild but increasing population and changes in land use throughout the Sacramento Valley and Sierra Nevada foothills may lead to increased pollutant damage in these forests. Although, better documented in other regions of the United States, little is known regarding the potential for acidic precipitation damage to Sierra Nevada forests. Only recently have studies directed towards understanding the potential interactive effects of ozone and acidic precipitation been undertaken. A key issue in resolving potential regional impacts of pollutants on forests is the extent to which research results can be scaled across genotypes and life-stages. Most of the pollution research to date has been performed using seedlings with varying degrees of genetic control. It is important to determine if the results obtained in such studies can be extrapolated to mature trees and to different genetic sources. In this paper, we present results from a one-year study examining the interactive effects of foliar exposure to acidic rain and ozone on the growth of ponderosa pine (Pinus ponderosa), a conifer known to be sensitive to ozone. The response to pollutants is characterized for both seedlings and mature tree branches of three genotypes grown in a common environment

  17. Stability enhancement of ozone-assisted laminar premixed Bunsen flames in nitrogen co-flow

    KAUST Repository

    Vu, Tran Manh

    2014-04-01

    Ozone (O3) is known as one of the strongest oxidizers and therefore is widely used in many applications. Typically in the combustion field, a combination of non-thermal plasma and combustion systems have been studied focusing on the effects of ozone on flame propagation speeds and ignition characteristics. Here, we experimentally investigated the effects of ozone on blowoff of premixed methane/air and propane/air flames over a full range of equivalence ratios at room temperature and atmospheric pressure by using a co-flow burner and a dielectric barrier discharge. The results with ozone showed that a nozzle exit jet velocity at the moment of flame blowoff (blowoff velocity) significantly increased, and flammability limits for both fuel-lean and rich mixtures were also extended. Ozone had stronger effects of percent enhancement in the blowoff velocity for off-stoichiometric mixtures, while minimum enhancements could be observed around stoichiometric conditions for both fuels showing linear positive dependence on a tested range of ozone concentration up to 3810ppm. Through chemical kinetic simulations, the experimentally observed trends of the enhancement in blowoff velocity were identified as a result of the modification of the laminar burning velocity. Two ozone decomposition pathways of O3+N2→O+O2+N2 and O3+H→O2+OH were identified as the most controlling steps. These reactions, coupled with fuel consumption characteristics of each fuel determined the degree of promotion in laminar burning velocities, supporting experimental observations on blowoff velocities with ozone addition. © 2013 The Combustion Institute.

  18. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature.

    Science.gov (United States)

    Cho, Youngjae; Muhlisin; Choi, Ji Hye; Hahn, Tae-Wook; Lee, Sung Ki

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10(-6) kg O3 h(-1)) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (pgenerator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed.

  19. Chronic bronchiolitis in non-human primates after prolonged ozone exposure

    International Nuclear Information System (INIS)

    Eustis, S.L.

    1979-01-01

    Bonnet monkeys (Macaca radiata) were exposed to 0.0, 0.5, and 0.8 ppM ozone for 7, 28, or 90 consecutive d, eight h per d. Changes in the lung evoked by prolonged oxidant exposure were evaluated by light microscopy, scanning electron microscopy, transmission electron microscopy, autoradiography, and morphometry. Morphological changes were principally characterized as a low-grade chronic respiratory bronchiolitis. Proximal generations of respiratory bronchioles were the most consistently affected region of the pulmonary acinus. Major features of the bronchiolitis were intraluminal accumulations of macrophages and hypertrophy and hyperplasia of cuboidal bronchiolar epithelial cells. The degree of inflammation was greatest at the 0.8 ppM ozone concentration at each exposure period. The number of inflammatory cells observed at 90 d, however, was about one-half that observed at 7 d. Tritiated thymidine labeling and differential cell counts of respiratory bronchiolar epithelium demonstrated a proliferative response and an increase in the proportion of cubiodal bronchiolar cells which presumably function as the progenitor cell during cell renewal and repair of the epithelium. The labeling index remained elevated above control values through 90 d of ozone exposure despite a reduction below 7 d values at both 28 and 90 d. The epithelial hyperplasia persisted through 90 d at a level similar to but slightly above that present at 7 d. Since cell differentials remained shifted at 28 and 90 d, it appears that persistent ozone exposure delayed maturation and transformation of cubiodal bronchiolar cells to their mature phenotype

  20. Exposure of Norway spruce to ozone increases the sensitivity of current year needles to photoinhibition and desiccation

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    1994-01-01

    decreases in net photosynthesis and chlorophyll fluorescence (FN/FM) were found during periods with co-occurrence of high ozone concentrations And high light intensities, indicating interactions between effects of ozone and photoinhibition. After termination of fumigation enhanced rates of photosynthesis...

  1. Commuters’ Personal Exposure to Ambient and Indoor Ozone in Athens, Greece

    Directory of Open Access Journals (Sweden)

    Krystallia K. Kalimeri

    2017-07-01

    Full Text Available This pilot study aimed to monitor the residential/office indoor, outdoor, and personal levels of ozone for people living, working, and commuting in Athens, Greece. Participants (16 persons of this study worked at the same place. Passive sampling analysis results did not indicate any limit exceedance (Directive 2008/50/EC: 120 µg/m3, World Health Organization (WHO Air Quality Guidelines 2005: 100 µg/m3. The highest “house-outdoor” concentration was noticed for participants living in the north suburbs of Athens, confirming the photochemical ozone formation at the northern parts of the basin during southwestern prevailing winds. The residential indoor to outdoor ratio (I/O was found to be significantly lower than unity, underlying the outdoor originality of the pollutant. The highest “office-indoor” concentration was observed in a ground-level building, characterized by the extensive use of photocopy machines and printers. Personal ozone levels were positively correlated only with indoor-office concentrations. A clear correlation of personal ozone levels to the time spent by the individuals during moving/staying outdoors was observed. On the other hand, no correlation was observed when focusing only on commuting time, due to the fact that transit time includes both on-foot and in-vehicle time periods, therefore activities associated with increased exposure levels, but also with pollutants removal by recirculating air filtering systems, respectively.

  2. Trends in Pinus ponderosa foliar pigment concentration due to chronic exposure of ozone and acid rain

    International Nuclear Information System (INIS)

    Neuman, L.; Houpis, J.; Anderson, P.

    1991-01-01

    To determine the effects of ozone and acid rain on mature Ponderosa pine trees, Lawrence Livermore National Lab. has collaborated with University of California Berkeley, University of California Davis, California State University Chico, and the US Forest Service at the latter's Chico Tree Improvement Center. Foliar tissue from mature grafted scions of Pinus ponderosa were exposed to two times ambient ozone for ten months and to acid rain (3.0 pH) weekly for 10 weeks using branch exposure chambers. Pigment extracts were analyzed spectrophotometrically for concentrations of chlorophylls a and b, and carotenoid pigments, at 662 nm, 644 nm, and 470 nm, respectively. Pigment concentrations were expressed on a surface area basis. Preliminary results revealed that chlorophyll a showed a downward trend due to the ozone treatment. Acid rain caused no effects on these three pigments, however, chlorophyll b showed an upward trend due to the interaction of ozone and acid rain. The carotenoid pigments showed no changes due to the treatments either singly, or in combination

  3. Adaptation of radish Raphanus sativus L. in response to continuous exposure to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Walmsley, L.; Ashmore, M.R.; Bell, J.N.B.

    1980-01-01

    A comparison was made between the development of radish Raphanus sativus L. cv. Cherry Belle in clean air and under continuous exposure to 0 x 17 ppm (340 ..mu..g m/sup -3/) of ozone. The area and dry weight of the individual leaves, and the dry weight of other plant organs, were determined at frequent, regular intervals throughout the experiment. Although the commercial yield of the ozone-treated plants, expressed as hypocotyl dry weight, was significantly reduced, changes in the pattern of development of these plants were observed which were of adaptive value. The pattern of assimilate distribution was altered so that new leaves were produced more rapidly in the ozone-treated plants. These later leaves were more resistant to ozone, showing a slower rate of senescence than the cotyledons or first leaves. Measurements of stomatal resistance suggested that this was an acquired, rather than an inherent, characteristic of the later leaves. By the end of the experiment, the relative growth rates in the two treatments did not differ significantly.

  4. Nocturnal surface ozone enhancement over Portugal during winter: Influence of different atmospheric conditions

    KAUST Repository

    Kulkarni, Pavan S.

    2016-09-24

    Four distinct nocturnal surface ozone (NSO) enhancement events were observed, with NSO concentration exceeding 80μg/m3, at multiple ozone (O3) monitoring stations (32 sites) in January, November and December between year 2000–2010, in Portugal. The reasonable explanation for the observed bimodal pattern of surface ozone with enhanced NSO concentration during nighttime has to be transport processes, as the surface ozone production ceases at nighttime. Simultaneous measurements of O3 at multiple stations during the study period in Portugal suggest that horizontal advection alone cannot explain the observed NSO enhancement. Thus, detailed analysis of the atmospheric conditions, simulated with the Weather Research and Forecasting (WRF) model, were performed to evaluate the atmospheric mechanisms responsible for NSO enhancement in the region. Simulations revealed that each event occurred as a result of one or the combination of different atmospheric processes such as, passage of a cold front followed by a subsidence zone; passage of a moving surface trough, with associated strong horizontal wind speed and vertical shear; combination of vertical and horizontal transport at the synoptic scale; formation of a low level jet with associated vertical mixing below the jet stream. The study confirmed that large-scale flow pattern resulting in enhanced vertical mixing in the nocturnal boundary layer, plays a key role in the NSO enhancement events, which frequently occur over Portugal during winter months. © 2016 Elsevier Ltd

  5. Nocturnal surface ozone enhancement over Portugal during winter: Influence of different atmospheric conditions

    KAUST Repository

    Kulkarni, Pavan S.; Dasari, Hari Prasad; Sharma, Ashish; Bortoli, D.; Salgado, Rui; Silva, A.M.

    2016-01-01

    Four distinct nocturnal surface ozone (NSO) enhancement events were observed, with NSO concentration exceeding 80μg/m3, at multiple ozone (O3) monitoring stations (32 sites) in January, November and December between year 2000–2010, in Portugal. The reasonable explanation for the observed bimodal pattern of surface ozone with enhanced NSO concentration during nighttime has to be transport processes, as the surface ozone production ceases at nighttime. Simultaneous measurements of O3 at multiple stations during the study period in Portugal suggest that horizontal advection alone cannot explain the observed NSO enhancement. Thus, detailed analysis of the atmospheric conditions, simulated with the Weather Research and Forecasting (WRF) model, were performed to evaluate the atmospheric mechanisms responsible for NSO enhancement in the region. Simulations revealed that each event occurred as a result of one or the combination of different atmospheric processes such as, passage of a cold front followed by a subsidence zone; passage of a moving surface trough, with associated strong horizontal wind speed and vertical shear; combination of vertical and horizontal transport at the synoptic scale; formation of a low level jet with associated vertical mixing below the jet stream. The study confirmed that large-scale flow pattern resulting in enhanced vertical mixing in the nocturnal boundary layer, plays a key role in the NSO enhancement events, which frequently occur over Portugal during winter months. © 2016 Elsevier Ltd

  6. Morphological study of the effects of ozone on rat lung. I. Short-term exposure

    International Nuclear Information System (INIS)

    Hiroshima, K.; Kohno, T.; Owada, H.; Hayashi, Y.

    1987-01-01

    In order to determine the effects of ozone on lungs and the course of cell renewal after damage, young male rats were exposed to 3 ppm of ozone for 4 hr. They were killed at 1, 6, 12, and 18 hr and 1, 2, 3, 4, 7, and 14 days after exposure. One hour before the killing, dividing cells were labeled with tritiated thymidine. Type 1 cells of centriacinar location and bronchiolar cells were severely damaged after exposure. Labeling indices of type 2 cells and bronchiolar nonciliated cells increased 1 day after exposure. Hyperplasia of type 2 cells and bronchiolar nonciliated cells was observed 2 and 3 days after exposure. Ciligenesis of bronchiolar ciliated cells occurred 4 days after exposure. Our study shows that injured type 1 cells are repaired by proliferation of type 2 cells and that injured bronchiolar ciliated and Clara cells are repaired by proliferation of bronchiolar nonciliated cells. These undifferentiated cells are probably progenitors of ciliated cells and Clara cells, and some nonciliated cells are in a transitional form between nonciliated and type 2 cells

  7. Ozone and limonene in indoor air: a source of submicron particle exposure.

    Science.gov (United States)

    Wainman, T; Zhang, J; Weschler, C J; Lioy, P J

    2000-12-01

    overall particle exposure. This study provides data for assessing the impact of outdoor ozone on indoor particles. This is important to determine the efficacy of the mass-based particulate matter standards in protecting public health because the indoor secondary particles can vary coincidently with the variations of outdoor fine particles in summer.

  8. Exposure-plant response of ambient ozone over the tropical Indian region

    Directory of Open Access Journals (Sweden)

    S. Deb Roy

    2009-07-01

    Full Text Available A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE and World Health Organization (WHO for vegetation protection (AOT40 have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months. Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. There is an underestimation of AOT40 in the model results during the periods of highest ozone concentration from December to March. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November to April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

  9. OXIDATIVE STRESS-DEPENDENT ALTERED IMMUNE RESPONSES AND CELL DEATH IN SUBSTANTIA NIGRA AFTER OZONE EXPOSURE IN RAT

    Directory of Open Access Journals (Sweden)

    Selva eRivas - Arancibia

    2015-05-01

    Full Text Available Parkinson’s disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent 1 spectrophotometric analysis for protein oxidation; 2 western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and 3 immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson’s disease.

  10. Impact of temporal upscaling and chemical transport model horizontal resolution on reducing ozone exposure misclassification

    Science.gov (United States)

    Xu, Yadong; Serre, Marc L.; Reyes, Jeanette M.; Vizuete, William

    2017-10-01

    We have developed a Bayesian Maximum Entropy (BME) framework that integrates observations from a surface monitoring network and predictions from a Chemical Transport Model (CTM) to create improved exposure estimates that can be resolved into any spatial and temporal resolution. The flexibility of the framework allows for input of data in any choice of time scales and CTM predictions of any spatial resolution with varying associated degrees of estimation error and cost in terms of implementation and computation. This study quantifies the impact on exposure estimation error due to these choices by first comparing estimations errors when BME relied on ozone concentration data either as an hourly average, the daily maximum 8-h average (DM8A), or the daily 24-h average (D24A). Our analysis found that the use of DM8A and D24A data, although less computationally intensive, reduced estimation error more when compared to the use of hourly data. This was primarily due to the poorer CTM model performance in the hourly average predicted ozone. Our second analysis compared spatial variability and estimation errors when BME relied on CTM predictions with a grid cell resolution of 12 × 12 km2 versus a coarser resolution of 36 × 36 km2. Our analysis found that integrating the finer grid resolution CTM predictions not only reduced estimation error, but also increased the spatial variability in daily ozone estimates by 5 times. This improvement was due to the improved spatial gradients and model performance found in the finer resolved CTM simulation. The integration of observational and model predictions that is permitted in a BME framework continues to be a powerful approach for improving exposure estimates of ambient air pollution. The results of this analysis demonstrate the importance of also understanding model performance variability and its implications on exposure error.

  11. Increased CCL24/eotaxin-2 with postnatal ozone exposure in allergen-sensitized infant monkeys is not associated with recruitment of eosinophils to airway mucosa

    International Nuclear Information System (INIS)

    Chou, Debbie L.; Gerriets, Joan E.; Schelegle, Edward S.; Hyde, Dallas M.; Miller, Lisa A.

    2011-01-01

    Epidemiology supports a causal link between air pollutant exposure and childhood asthma, but the mechanisms are unknown. We have previously reported that ozone exposure can alter the anatomic distribution of CD25+ lymphocytes in airways of allergen-sensitized infant rhesus monkeys. Here, we hypothesized that ozone may also affect eosinophil trafficking to allergen-sensitized infant airways. To test this hypothesis, we measured blood, lavage, and airway mucosa eosinophils in 3-month old monkeys following cyclical ozone and house dust mite (HDM) aerosol exposures. We also determined if eotaxin family members (CCL11, CCL24, CCL26) are associated with eosinophil location in response to exposures. In lavage, eosinophil numbers increased in animals exposed to ozone and/or HDM. Ozone + HDM animals showed significantly increased CCL24 and CCL26 protein in lavage, but the concentration of CCL11, CCL24, and CCL26 was independent of eosinophil number for all exposure groups. In airway mucosa, eosinophils increased with exposure to HDM alone; comparatively, ozone and ozone + HDM resulted in reduced eosinophils. CCL26 mRNA and immunofluorescence staining increased in airway mucosa of HDM alone animals and correlated with eosinophil volume. In ozone + HDM animal groups, CCL24 mRNA and immunofluorescence increased along with CCR3 mRNA, but did not correlate with airway mucosa eosinophils. Cumulatively, our data indicate that ozone exposure results in a profile of airway eosinophil migration that is distinct from HDM mediated pathways. CCL24 was found to be induced only by combined ozone and HDM exposure, however expression was not associated with the presence of eosinophils within the airway mucosa. -- Highlights: ► Ozone can modulate the localization of eosinophils in infant allergic airways. ► Expression of eotaxins within the lung is affected by ozone and allergen exposure. ► CCL24 induction by ozone and allergen exposure is not linked to eosinophilia.

  12. Increased CCL24/eotaxin-2 with postnatal ozone exposure in allergen-sensitized infant monkeys is not associated with recruitment of eosinophils to airway mucosa

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Debbie L.; Gerriets, Joan E. [California National Primate Research Center, UC Davis, Davis, CA 95616 (United States); Schelegle, Edward S.; Hyde, Dallas M. [California National Primate Research Center, UC Davis, Davis, CA 95616 (United States); Department of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616 (United States); Miller, Lisa A., E-mail: lmiller@ucdavis.edu [California National Primate Research Center, UC Davis, Davis, CA 95616 (United States); Department of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616 (United States)

    2011-12-15

    Epidemiology supports a causal link between air pollutant exposure and childhood asthma, but the mechanisms are unknown. We have previously reported that ozone exposure can alter the anatomic distribution of CD25+ lymphocytes in airways of allergen-sensitized infant rhesus monkeys. Here, we hypothesized that ozone may also affect eosinophil trafficking to allergen-sensitized infant airways. To test this hypothesis, we measured blood, lavage, and airway mucosa eosinophils in 3-month old monkeys following cyclical ozone and house dust mite (HDM) aerosol exposures. We also determined if eotaxin family members (CCL11, CCL24, CCL26) are associated with eosinophil location in response to exposures. In lavage, eosinophil numbers increased in animals exposed to ozone and/or HDM. Ozone + HDM animals showed significantly increased CCL24 and CCL26 protein in lavage, but the concentration of CCL11, CCL24, and CCL26 was independent of eosinophil number for all exposure groups. In airway mucosa, eosinophils increased with exposure to HDM alone; comparatively, ozone and ozone + HDM resulted in reduced eosinophils. CCL26 mRNA and immunofluorescence staining increased in airway mucosa of HDM alone animals and correlated with eosinophil volume. In ozone + HDM animal groups, CCL24 mRNA and immunofluorescence increased along with CCR3 mRNA, but did not correlate with airway mucosa eosinophils. Cumulatively, our data indicate that ozone exposure results in a profile of airway eosinophil migration that is distinct from HDM mediated pathways. CCL24 was found to be induced only by combined ozone and HDM exposure, however expression was not associated with the presence of eosinophils within the airway mucosa. -- Highlights: Black-Right-Pointing-Pointer Ozone can modulate the localization of eosinophils in infant allergic airways. Black-Right-Pointing-Pointer Expression of eotaxins within the lung is affected by ozone and allergen exposure. Black-Right-Pointing-Pointer CCL24 induction by

  13. The Variable Effects of Ozone and/or Diesel Particulate Inhalation Exposure on Allergic Airways Responses in Mice

    Science.gov (United States)

    Exposure to diesel exhaust particle matter (DEP) associated with the combustion of diesel fuel exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (O3). Since levels of both pollutants in ambient air are e...

  14. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    International Nuclear Information System (INIS)

    Calatayud, Vicent; Cervero, Julia; Calvo, Esperanza; Garcia-Breijo, Francisco-Jose; Reig-Arminana, Jose; Sanz, Maria Jose

    2011-01-01

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD 1.6 ) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  15. Responses of evergreen and deciduous Quercus species to enhanced ozone levels

    Energy Technology Data Exchange (ETDEWEB)

    Calatayud, Vicent, E-mail: calatayud_viclor@gva.e [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Cervero, Julia; Calvo, Esperanza [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Garcia-Breijo, Francisco-Jose [Laboratorio de Anatomia e Histologia Vegetal ' Julio Iranzo' , Jardin Botanico, Universitat de Valencia, c/Quart 80, 46008 Valencia (Spain); Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Reig-Arminana, Jose [Departamento de Ecosistemas Agroforestales, Escuela Tecnica Superior del Medio Rural y Enologia, Universidad Politecnica de Valencia, Avda. Blasco Ibanez 21, 46010 Valencia (Spain); Sanz, Maria Jose [Instituto Universitario CEAM-UMH, Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

    2011-01-15

    Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD{sub 1.6}) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. - Ozone tolerance overlapped with leaf traits in four Quercus species.

  16. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    Science.gov (United States)

    Patil, Jagadish G.; Vijayan, T.

    2010-02-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 102-106 m-3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  17. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Jagadish G; Vijayan, T, E-mail: jagdishlove@gmail.co [Mahatma Education Society' s ' Pillai' s Institute of Information Technology, Engineering, Media Studies and Research' Dr. K M Vasudevan Pillai' s Campus, Sector 16, New Panvel, Navi Mumbai - 410 206 (India)

    2010-02-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over {mu}A) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10{sup 2}-10{sup 6} m{sup -3} are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  18. Modeling and characterization of field-enhanced corona discharge in ozone-generator diode

    International Nuclear Information System (INIS)

    Patil, Jagadish G; Vijayan, T

    2010-01-01

    Electric field enhanced corona plasma discharge in ozone generator diode of axial symmetry has been investigated and characterized in theory. The cathode K of diode is made of a large number of sharpened nozzles arranged on various radial planes on the axial mast and pervaded in oxygen gas inside the anode cup A, produces high fields over MV/m and aids in the formation of a corona plume of dense ozone cloud over the cathode surface. An r-z finite difference scheme has been devised and employed to numerically determine the potential and electric field distributions inside the diode. The analyses of cathode emissions revealed a field emission domain conformed to modified Child-Langmuir diode-current. Passage of higher currents (over μA) in shorter A-K gaps d gave rise to cathode heated plasma extending from the corona to Saha regimes depending on local temperature. Plasma densities of order 10 2 -10 6 m -3 are predicted in these. For larger d however, currents are smaller and heating negligible and a negative corona favoring ozone formation is attained. High ozone yields about 20 per cent of oxygen input is predicted in this domain. The generator so developed will be applied to various important applications such as, purification of ambient air /drinking water, ozone therapy, and so on.

  19. Spatial associations between social groups and ozone air pollution exposure in the Beijing urban area.

    Science.gov (United States)

    Zhao, Xinyi; Cheng, Hongguang; He, Siyuan; Cui, Xiangfen; Pu, Xiao; Lu, Lu

    2018-07-01

    Few studies have linked social factors to air pollution exposure in China. Unlike the race or minority concepts in western countries, the Hukou system (residential registration system) is a fundamental reason for the existence of social deprivation in China. To assess the differences in ozone (O 3 ) exposure among social groups, especially groups divided by Hukou status, we assigned estimates of O 3 exposure to the latest census data of the Beijing urban area using a kriging interpolation model. We developed simultaneous autoregressive (SAR) models that account for spatial autocorrelation to identify the associations between O 3 exposure and social factors. Principal component regression was used to control the multicollinearity bias as well as explore the spatial structure of the social data. The census tracts (CTs) with higher proportions of persons living alone and migrants with non-local Hukou were characterized by greater exposure to ambient O 3 . The areas with greater proportions of seniors had lower O 3 exposure. The spatial distribution patterns were similar among variables including migrants, agricultural population and household separation (population status with separation between Hukou and actual residences), which fit the demographic characteristics of the majority of migrants. Migrants bore a double burden of social deprivation and O 3 pollution exposure due to city development planning and the Hukou system. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Demonstration of AIRS Total Ozone Products to Operations to Enhance User Readiness

    Science.gov (United States)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

    2014-01-01

    Cyclogenesis is a key forecast challenge at operational forecasting centers such as WPC and OPC, so these centers have a particular interest in unique products that can identify key storm features. In some cases, explosively developing extratropical cyclones can produce hurricane force, non-convective winds along the East Coast and north Atlantic as well as the Pacific Ocean, with the potential to cause significant damage to life and property. Therefore, anticipating cyclogenesis for these types of storms is crucial for furthering the NOAA goal of a "Weather Ready Nation". Over the last few years, multispectral imagery (i.e. RGB) products have gained popularity among forecasters. The GOES-R satellite champion at WPC/OPC has regularly evaluated the Air Mass RGB products from GOES Sounder, MODIS, and SEVIRI to aid in forecasting cyclogenesis as part of ongoing collaborations with SPoRT within the framework of the GOES-R Proving Ground. WPC/OPC has used these products to identify regions of stratospheric air associated with tropopause folds that can lead to cyclogenesis and hurricane force winds. RGB products combine multiple channels or channel differences into multi-color imagery in which different colors represent a particular cloud or air mass type. Initial interaction and feedback from forecasters evaluating the legacy Air Mass RGBs revealed some uncertainty regarding what physical processes the qualitative RGB products represent and color interpretation. To enhance forecaster confidence and interpretation of the Air Mass RGB, NASA SPoRT has transitioned a total column ozone product from AIRS retrievals to the WPC/OPC. The use of legacy AIRS demonstrates future JPSS capabilities possible with CrIS or OMPS. Since stratospheric air can be identified by anomalous potential vorticity and warm, dry, ozone-rich air, hyperspectral infrared sounder ozone products can be used in conjunction with the Air Mass RGB for identifying the role of stratospheric air in explosive

  1. Characterizing the impact of projected changes in climate and air quality on human exposures to ozone.

    Science.gov (United States)

    Dionisio, Kathie L; Nolte, Christopher G; Spero, Tanya L; Graham, Stephen; Caraway, Nina; Foley, Kristen M; Isaacs, Kristin K

    2017-05-01

    The impact of climate change on human and environmental health is of critical concern. Population exposures to air pollutants both indoors and outdoors are influenced by a wide range of air quality, meteorological, behavioral, and housing-related factors, many of which are also impacted by climate change. An integrated methodology for modeling changes in human exposures to tropospheric ozone (O 3 ) owing to potential future changes in climate and demographics was implemented by linking existing modeling tools for climate, weather, air quality, population distribution, and human exposure. Human exposure results from the Air Pollutants Exposure Model (APEX) for 12 US cities show differences in daily maximum 8-h (DM8H) exposure patterns and levels by sex, age, and city for all scenarios. When climate is held constant and population demographics are varied, minimal difference in O 3 exposures is predicted even with the most extreme demographic change scenario. In contrast, when population is held constant, we see evidence of substantial changes in O 3 exposure for the most extreme change in climate. Similarly, we see increases in the percentage of the population in each city with at least one O 3 exposure exceedance above 60 p.p.b and 70 p.p.b thresholds for future changes in climate. For these climate and population scenarios, the impact of projected changes in climate and air quality on human exposure to O 3 are much larger than the impacts of changing demographics. These results indicate the potential for future changes in O 3 exposure as a result of changes in climate that could impact human health.

  2. Mechanism for enhanced degradation of clofibric acid in aqueous by catalytic ozonation over MnOx/SBA-15.

    Science.gov (United States)

    Sun, Qiangqiang; Wang, Yu; Li, Laisheng; Bing, Jishuai; Wang, Yingxin; Yan, Huihua

    2015-04-09

    Comparative experiments were conducted to investigate the catalytic ability of MnO(x)/SBA-15 for the ozonation of clofibric acid (CA) and its reaction mechanism. Compared with ozonation alone, the degradation of CA was barely enhanced, while the removal of TOC was significantly improved by catalytic ozonation (O3/MnO(x)/SBA-15). Adsorption of CA and its intermediates by MnO(x)/SBA-15 was proved unimportant in O3/MnO(x)/SBA-15 due to the insignificant adsorption of CA and little TOC variation after ceasing ozone in stopped-flow experiment. The more remarkably inhibition effect of sodium bisulfite (NaHSO3) on the removal of TOC in catalytic ozonation than in ozonation alone elucidated that MnO(x)/SBA-15 facilitated the generation of hydroxyl radicals (OH), which was further verified by electron spin-resonance spectroscopy (ESR). Highly dispersed MnO(x) on SBA-15 were believed to be the main active component in MnO(x)/SBA-15. Some intermediates were indentified and different degradation routes of CA were proposed in both ozonation alone and catalytic ozonation. The amounts of small molecular carboxylic acids (i.e., formic acid (FA), acetic acid (AA) and oxalic acid (OA)) generated in catalytic ozonation were lower than in ozonation alone, resulting from the generation of more OH. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. [The effects of exposure to ozone on sperm quality in Wuhan].

    Science.gov (United States)

    Tian, X J; Wang, X C; Ye, B; Li, C L; Zhang, Y; Ma, L

    2017-03-06

    Objective: To evaluate the effects of exposure to ozone (O(3)) on sperm quality during different stages of spermatogenesis. Methods: All 1 780 subjects attending to the Reproductive Medicine Center in Renmin Hospital of Wuhan University were recruited from April, 4, 2013 to June, 30, 2015. The subjects were living in Wuhan more than 3 months before attending to the program, aged 20 to 40 years. Semen quality (sperm concentration and sperm count) were measured according to standardized protocols. Corresponding daily 8 hours average concentration of O(3), other polluted concentration, average temperature and relative humidity were collected in different time, including lag 0, 10, 70 and 90 d, and lag 0-9 d, lag 10-14 d, lag 70-90 d and lag 0-90 d. After controlling the age, BMI, education level and other confounders, generalized linear Model was used to investigate the association between O(3) and sperm quality during different stages of spermatogenesis. Results: Average daily concentration of O(3) during the study period was (114.20±74.88) μg/m(3) and the mean values of sperm concentration and count were (76.32±50.17) millions/ml and (164.77 ± 133.05) millions/sample, respectively. Exposure to O(3) was associated with decreasing sperm concentration and count. For every 1 μg/m(3) increase of O(3), the decrease of sperm concentration during lag 10, lag 0-9 and lag 10-14 days exposure windows were 0.040 (95% CI: 0.004-0.077) millions/ml, 0.081 (95% CI: 0.003-0.158) millions/ml and 0.059 (95% CI: 0.001-0.116) millions/ml, respectively. And the decrease of sperm count during lag 10, lag 0-9 days exposure windows were 0.105 (95% CI: 0.008-0.202) millions/sample and 0.221 (95% CI: 0.016-0.426) millions/sample. After stratification, in the ozone concentration sperm concentration was 0.249 (95% CI: 0.028-0.470) millions/ml. After sensitivity analysis, the effects of exposure to ozone on sperm concentration and sperm count remained relatively unchanged. Conclusion: Our

  4. Comparison of seasonal variations of ozone exposure and fluxes in a Mediterranean Holm oak forest between the exceptionally dry 2003 and the following year

    International Nuclear Information System (INIS)

    Gerosa, Giacomo; Finco, Angelo; Mereu, Simone; Vitale, Marcello; Manes, Fausto; Denti, Antonio Ballarin

    2009-01-01

    Ozone and energy fluxes have been measured using the eddy covariance technique, from June to December 2004 in Castelporziano near Rome (Italy), and compared to similar measurements made in the previous year. The studied ecosystem consisted in a typical Mediterranean Holm oak forest. Stomatal fluxes have been calculated using the resistance analogy and by inverting the Penmann-Monteith equation. Results showed that the average stomatal contribution accounts for 42.6% of the total fluxes. Non-stomatal deposition proved to be enhanced by increasing leaf wetness and air humidity during the autumnal months. From a comparison of the two years, it can be inferred that water supply is the most important limiting factor for ozone uptake and that prolonged droughts alter significantly the stomatal conductance, even 2 months after the soil water content is replenished. Ozone exposure, expressed as AOT40, behaves similarly to the cumulated stomatal flux in dry conditions whereas a different behaviour for the two indices appears in wet autumnal conditions. A difference also occurs between the two years. - Ozone fluxes to a Holm oak coastal forest show inter-annual variations depending on meteorological conditions and water availability.

  5. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development

    International Nuclear Information System (INIS)

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-01-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O_3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions – pollen originating from plants raised in charcoal-Purafil"® filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O_3. The O_3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O_3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O_3 × CFA and CFA × O_3 crossed plants. This suggests O_3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol"−"1 O_3 (10 h d"−"1) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit – a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O_3, and potentially other gaseous pollutants, on reproductive biology during ‘risk assessment’ exercises. - Highlights: • Environmentally-relevant levels of ozone exert negative effects on pollen viability that translate into direct impacts on fruit yield. • Negative impacts of O_3 pollution on reproductive processes were evident regardless of the stage of plant development. • Exposure to environmentally-relevant levels of O_3

  6. Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

    Energy Technology Data Exchange (ETDEWEB)

    Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K

    2004-09-01

    We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-{beta}-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation.

  7. Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

    International Nuclear Information System (INIS)

    Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K.

    2004-01-01

    We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-β-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation

  8. Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

    International Nuclear Information System (INIS)

    Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T.

    1990-01-01

    Ozone (O 3 ) and nitrogen dioxide (NO 2 ) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O 3 at 0.1, 0.3, or 1 ppm; NO 2 at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O 3 and 3 ppm NO 2 . Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O 3 . Exposure to 10 ppm NO 2 resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO 2 and depressed following 3 and 10 ppm. The O 3 /NO 2 mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O 3 . This study has demonstrated that acute exposure to either O 3 or NO 2 can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively

  9. Mechanism for enhanced degradation of clofibric acid in aqueous by catalytic ozonation over MnOx/SBA-15

    International Nuclear Information System (INIS)

    Sun, Qiangqiang; Wang, Yu; Li, Laisheng; Bing, Jishuai; Wang, Yingxin; Yan, Huihua

    2015-01-01

    Highlights: • Clofibric acid (CA) is efficiently mineralized by O 3 /MnO x /SBA-15. • Adsorption of CA and its intermediates on MnO x /SBA-15 is proved unimportant. • Initiation of hydroxyl radicals (·OH) is enhanced in O 3 /MnO x /SBA-15. • Uniformly distributed MnO x accounts for the high activity of MnO x /SBA-15. • Degradation routes of CA in ozonation alone and catalytic ozonation are proposed. - Abstract: Comparative experiments were conducted to investigate the catalytic ability of MnO x /SBA-15 for the ozonation of clofibric acid (CA) and its reaction mechanism. Compared with ozonation alone, the degradation of CA was barely enhanced, while the removal of TOC was significantly improved by catalytic ozonation (O 3 /MnO x /SBA-15). Adsorption of CA and its intermediates by MnO x /SBA-15 was proved unimportant in O 3 /MnO x /SBA-15 due to the insignificant adsorption of CA and little TOC variation after ceasing ozone in stopped-flow experiment. The more remarkably inhibition effect of sodium bisulfite (NaHSO 3 ) on the removal of TOC in catalytic ozonation than in ozonation alone elucidated that MnO x /SBA-15 facilitated the generation of hydroxyl radicals (·OH), which was further verified by electron spin-resonance spectroscopy (ESR). Highly dispersed MnO x on SBA-15 were believed to be the main active component in MnO x /SBA-15. Some intermediates were indentified and different degradation routes of CA were proposed in both ozonation alone and catalytic ozonation. The amounts of small molecular carboxylic acids (i.e., formic acid (FA), acetic acid (AA) and oxalic acid (OA)) generated in catalytic ozonation were lower than in ozonation alone, resulting from the generation of more ·OH

  10. Regional differences in DNA replication in nasal epithelium following acute ozone or cigarette smoke exposure

    International Nuclear Information System (INIS)

    Johnson, N.F.; Hotchkiss, J.A.; Harkema, J.R.; Henderson, R.F.; Mauderly, J.L.; Cuddihy, R.G.

    1988-01-01

    The epithelium of the anterior nasal cavity is composed of four cell types, squamous, respiratory, cuboidal, and olfactory cells. We monitored proliferation In these tissues by bromodeoxy-uridine (BrdUrd) incorporation; the labeled cells were identified by using a monoclonal antibody that recognizes BrdUrd. The respiratory, cuboidal and olfactory epithelia had low cell turnover (1-labeled ceIl/mm basal lamina). Squamous epithelium contained 40-labeled cells per mm basal lamina. Following exposure to diluted mainstream cigarette smoke, a transient, but marked increase in DNA replication was seen in the cuboidal epithelium. In contrast, ozone exposure was associated with DNA replication in the olfactory and respiratory epithelium, as well as in the cuboidal epithelium. These studies show that the sensitivity of nasal epithelium to irritants can be assayed by measuring DNA replication. (author)

  11. Regional differences in DNA replication in nasal epithelium following acute ozone or cigarette smoke exposure

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, N F; Hotchkiss, J A; Harkema, J R; Henderson, R F; Mauderly, J L; Cuddihy, R G

    1988-12-01

    The epithelium of the anterior nasal cavity is composed of four cell types, squamous, respiratory, cuboidal, and olfactory cells. We monitored proliferation In these tissues by bromodeoxy-uridine (BrdUrd) incorporation; the labeled cells were identified by using a monoclonal antibody that recognizes BrdUrd. The respiratory, cuboidal and olfactory epithelia had low cell turnover (1-labeled ceIl/mm basal lamina). Squamous epithelium contained 40-labeled cells per mm basal lamina. Following exposure to diluted mainstream cigarette smoke, a transient, but marked increase in DNA replication was seen in the cuboidal epithelium. In contrast, ozone exposure was associated with DNA replication in the olfactory and respiratory epithelium, as well as in the cuboidal epithelium. These studies show that the sensitivity of nasal epithelium to irritants can be assayed by measuring DNA replication. (author)

  12. Determinants of personal exposure to ozone in school children. Results from a panel study in Greece.

    Science.gov (United States)

    Dimakopoulou, Konstantina; Grivas, Georgios; Samoli, Evangelia; Rodopoulou, Sophia; Spyratos, Dionisis; Papakosta, Despoina; Karakatsani, Anna; Chaloulakou, Archontoula; Katsouyanni, Klea

    2017-04-01

    In the wider framework of the RESPOZE (ReSPiratory effects of OZone Exposure in Greek children) panel study, we investigated possible determinants of O 3 exposure of school children, measured with personal passive samplers, in Athens and Thessaloniki, Greece. Personal exposure to O 3 was measured for five weeks spread along the academic year 2013-14, in 186 school children in Athens and Thessaloniki, Greece. At the same time, at-school outdoor measurements were performed and ambient levels of 8-h daily maximum O 3 from fixed sites were collected. We also collected information on lifestyle and housing characteristics through an extended general questionnaire (GQ) and each participant completed daily time activity diaries (TADs) during the study period. Mean outdoor concentrations were higher during the warmer months, in the suburbs of the cities and in Athens. Personal exposure concentrations were significantly lower compared to outdoor. Daily levels of at-school outdoor and ambient levels of O 3 from fixed sites were significant determinants of personal exposure to O 3 . For a 10μg/m 3 increase in at-school outdoor O 3 concentrations and PM 10 measurements a 20.9% (95% CI: 13%, 28%) increase in personal exposure to O 3 was found. For a half an hour more spent in transportation an average increase of 7% (95% CI: 0.3%, 14.6%) in personal exposure to O 3 was observed. Among other possible determinants, time spent in transportation (TAD variable) and duration of open windows were the ones associated with personal O 3 exposure levels. Our results support the use of outdoor and ambient measurements from fixed sites in epidemiological studies as a proxy of personal exposure to O 3 , but this has to be calibrated taking into account personal measurements and time-activity patterns. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The effects of ozone exposure and associated injury mechanisms on the central nervous system.

    Science.gov (United States)

    Martínez-Lazcano, Juan Carlos; González-Guevara, Edith; del Carmen Rubio, María; Franco-Pérez, Javier; Custodio, Verónica; Hernández-Cerón, Miguel; Livera, Carlos; Paz, Carlos

    2013-01-01

    Ozone (O3) is a component of photochemical smog, which is a major air pollutant and demonstrates properties that are harmful to health because of the toxic properties that are inherent to its powerful oxidizing capabilities. Environmental O3 exposure is associated with many symptoms related to respiratory disorders, which include loss of lung function, exacerbation of asthma, airway damage, and lung inflammation. The effects of O3 are not restricted to the respiratory system or function - adverse effects within the central nervous system (CNS) such as decreased cognitive response, decrease in motor activity, headaches, disturbances in the sleep-wake cycle, neuronal dysfunctions, cell degeneration, and neurochemical alterations have also been described; furthermore, it has also been proposed that O3 could have epigenetic effects. O3 exposure induces the reactive chemical species in the lungs, but the short half-life of these chemical species has led some authors to attribute the injurious mechanisms observed within the lungs to inflammatory processes. However, the damage to the CNS induced by O3 exposure is not well understood. In this review, the basic mechanisms of inflammation and activation of the immune system by O3 exposure are described and the potential mechanisms of damage, which include neuroinflammation and oxidative stress, and the signs and symptoms of disturbances within the CNS caused by environmental O3 exposure are discussed.

  14. Meta-analysis of the association between short-term exposure to ambient ozone and respiratory hospital admissions

    International Nuclear Information System (INIS)

    Ji Meng; Bell, Michelle L; Cohan, Daniel S

    2011-01-01

    Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through ≥ 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publication bias.

  15. Enhanced WWTP effluent organic matter removal in hybrid ozonation-coagulation (HOC) process catalyzed by Al-based coagulant

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Jin, Pengkang, E-mail: pkjin@hotmail.com [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Hou, Rui [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Yang, Lei [Department of Materials Science and Engineering, Monash University, Clayton, VIC, 3800 (Australia); Wang, Xiaochang C., E-mail: xcwang@xauat.edu.cn [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China)

    2017-04-05

    Highlights: • A novel HOC process was firstly put forward to apply in wastewater reclamation. • Interactions between ozone and Al-based coagulants was found in the HOC process. • Ozonation can be catalyzed and enhanced by Al-based coagulants in the HOC process. • HOC process showed better organics removal than pre-ozonation-coagulation process. - Abstract: A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1 mgO{sub 3}/mg DOC at each pH value (pH 5, 7 and 9). In order to interpret the mechanism of the HOC process, ozone decomposition was monitored. The results indicated that ozone decomposed much faster in the HOC process. Moreover, by using the reagent of O{sub 3}-resistant hydroxyl radical (·OH) probe compound, para-chlorobenzoic acid (pCBA), and electron paramagnetic resonance (EPR) analysis, it was observed that the HOC process generated higher content of ·OH compared with pre-ozonation process. This indicates that the ·OH oxidation reaction as the key step can be catalyzed and enhanced by Al-based coagulants and their hydrolyzed products in this developed process. Thus, based on the catalytic effects of Al-based coagulants on ozonation, the HOC process provides a promising alternative to the conventional technology for wastewater reclamation in terms of higher efficiency.

  16. Driver exposure to volatile organic compounds, CO, ozone, and NO2 under different driving conditions

    International Nuclear Information System (INIS)

    Changchuan Chan; Oezkaynak, H.; Spengler, J.D.; Sheldon, L.

    1991-01-01

    The in-vehicle concentrations of 24 gasoline-related volatile organic compounds (VOCs) and three criteria air pollutants, ozone, carbon monoxide, and nitrogen dioxide, were measured in the summer of 1988, in Raleigh, NC. Two four-door sedan of different ages were used to evaluate in-vehicle concentrations of these compounds under different driving conditions. Factors that could influence driver exposure, such as different traffic patterns, car model, vehicle ventilation conditions, and driving periods, were evaluated. Isopentane was the most abundant aliphatic hydrocarbon and toluene was the most abundant aromatic VOC measured inside the vehicles. In-vehicle VOC and CO concentrations were highest for the urban roadway, second highest for the interstate highway, and lowest for the rural road. The median concentration ratio of urban/interstate/rural for each VOC was about 10/6/1. No differences in in-vehicle VOC concentrations were found between morning and afternoon rush hour driving, but higher in-vehicle ozone and NO 2 concentrations were found during afternoon driving. In-vehicle VOC levels were lowest with the air conditioner on and highest when the vent was open with the fan on. The in-vehicle/car exterior concentration ratio for VOCs, CO, and NO 2 was slightly higher than 1. The VOC concentration measured by a pedestrian on the urban sidewalk was lower than the in-vehicle measurements but higher than the fixed-site measurements but higher than the fixed-site measurements on urban roadways 50 m from streets. The VOC measurements were positively correlated with the CO measurement and negatively correlated with the ozone measurement

  17. Impacts of enhanced fertilizer applications on tropospheric ozone and crop damage over sub-Saharan Africa

    Science.gov (United States)

    Huang, Yaoxian; Hickman, Jonathan E.; Wu, Shiliang

    2018-05-01

    Fertilizer-induced nitrogen oxides (NOx) emissions in sub-Saharan Africa are expected to increase substantially in the coming decades, driven by increasing application of fertilizers to increase crop yields in an effort to attain food security across the continent. In many parts of sub-Saharan Africa, surface ozone (O3) is sensitive to increasing atmospheric concentrations of NOx. In this study, we employ the GEOS-Chem chemical transport model to conduct a preliminary investigation of the impacts on O3 air quality and the consequential crop damage associated with increasing fertilizer-induced NOx emissions in sub-Saharan Africa. Our simulation results, constrained by field NO flux measurements for the years 2011 and 2012 in response to a variety of fertilizer application rates in western Kenya, show that the enhancements in NO flux with fertilizer application rate of 150 kg N ha-1 can increase surface NOx and O3 concentrations by up to 0.36 and 2.8 ppbv respectively during the growing season. At the same time, accumulated O3 exposure during the crop growing season (expressed as AOT40 values) could increase by up to 496 ppb h, leading to crop yield decline of about 0.8% for O3-sensitive crops. Our results suggest that, when accounting for the consequential impacts on surface O3 air quality and crop damage over sub-Saharan Africa, agricultural intensification is possible without substantial impacts on crop productivity because the relatively small decline of crop yield resulting from O3 damage appears unlikely to outweigh the gain in crop yield from fertilization.

  18. Compensation processes of Aleppo pine (Pinus halepensis Mill.) to ozone exposure and drought stress

    International Nuclear Information System (INIS)

    Inclan, R.; Gimeno, B.S.; Dizengremel, P.; Sanchez, M.

    2005-01-01

    A long-term experiment was performed to study the effects of O 3 and drought-stress (DS) on Aleppo pine seedlings (Pinus halepensis Mill.) exposed in open-top chambers. Ozone reduced gas exchange rates, ribulose-1,5-biphosphate carboxylase/oxygenase activity (Rubisco), aboveground C and needle N concentrations and C/N ratio and Ca concentrations of the twigs under 3 mm (twigs Pd ), C/N ratio, twigs<3 Ca, plant growth, aerial biomass and increased N, twigs with a diameter above 3 mm P and Mg concentrations. The combined exposure to both stresses increased N concentrations of twigs<3 and roots and aboveground biomass K content and decreased root C, maximum daily assimilation rate and instantaneous water use efficiency. The sensitivity of Aleppo pine to both stresses is determined by plant internal resource allocation and compensation mechanisms to cope with stress. - Ozone and drought stress induce the activation of similar processes related to C and N metabolism

  19. Enhanced photocatalytic ozonation of organics by g-C3N4 under visible light irradiation

    International Nuclear Information System (INIS)

    Liao, Gaozu; Zhu, Dongyun; Li, Laisheng; Lan, Bingyan

    2014-01-01

    Highlights: • g-C 3 N 4 is employed as active catalyst in the photocatalytic ozonation system. • The more negative conduction band of g-C 3 N 4 benefits the transfer of electrons. • The synergistic effect between photocatalysis and ozonation is promoted by g-C 3 N 4 . • Enhanced degradation of oxalic acid and biphenol A is achieved via g-C 3 N 4 /Vis/O 3 . - Abstract: Graphitic carbon nitride (g-C 3 N 4 ) was employed as the active photocatalyst in the photocatalytic ozonation coupling system in the present study. g-C 3 N 4 was prepared by directly heating thiourea in air at 550 °C. XRD, FT-IR, UV–vis was used to characterize the structure and optical property. Oxalic acid and bisphenol A were selected as model substances for photocatalytic ozonation reactions to evaluate the catalytic ability of g-C 3 N 4 (g-C 3 N 4 /Vis/O 3 ). The results showed that the degradation ratio of oxalic acid with g-C 3 N 4 /Vis/O 3 was 65.2% higher than the sum of ratio when it was individually decomposed by g-C 3 N 4 /Vis and O 3 . The TOC removal of biphenol A with g-C 3 N 4 /Vis/O 3 was 2.17 times as great as the sum of the ratio when using g-C 3 N 4 /Vis and O 3 . This improvement was attributed to the enhanced synergistic effect between photocatalysis and ozonation by g-C 3 N 4 . Under visible light irradiation, the photo-generated electrons produced on g-C 3 N 4 facilitated the electrons transfer owing to the more negative conduction band potential (−1.3 V versus NHE). It meant that the photo-generated electrons could be trapped by ozone and reaction with it more easily. Subsequently, the yield of hydroxyl radicals was improved so as to enhance the organics degradation efficiency. This work indicated that metal-free g-C 3 N 4 could be an excellent catalyst for mineralization of organic compounds in waste control

  20. Enhanced biodegradation of petrochemical wastewater using ozonation and BAC advanced treatment system

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chi-Kang; Tsai, Tsung-Yueh; Liu, Jiunn-Ching; Chen, Mei-Chen [Energy and Resources Labs., ITRI, Hsinchu (Taiwan)

    2001-07-01

    The characteristics of degradation/conversion of bio-refractory and the growth of a biofilm are investigated in laboratory-scale pre-ozonation and lifted moving-bed biological activated carbon (BAC) advanced treatment processes treating phenol, benzoic acid, aminobenzoic acid and petrochemical industry wastewater which contains acrylonitrile butadiene styrene (ABS). The optimal reaction time and ozone dosage of pre-ozonation for bio-refractory conversion were determined to be 30 min and 100-200mg O{sub 3}/hr, respectively. After pre-ozonation of 30 min treatment, BOD{sub 5}/COD ratio of influent and effluent increased apparently from 20 to 35%, approximately. However, the change of pH in pre-ozonation was inconspicuous. The optimal flow rate of influent and air were controlled at 1.6 1/h and 120-l50nl/min in lifted moving-bed BAC advanced treatment reactor. A COD removal efficiency of 85-95% and 70-90% may be maintained by using an organic loading of 3.2-6.3kg COD/m{sup 3} day and 0.6-1.6 kg-COD/m{sup 3} day with an HRT of 6.0 h as secondary and advanced treatment system, respectively. The time required for the BAC bed to be regenerated by a thermal regeneration is prolonged 4-5 times more than that of GAC system. It can be estimated that the enhanced COD removal capability of the biofilm was not only due to the increase in the COD removal capability of acclimated bacteria, but also due to species succession of bacteria in bio-film ecosystem. (Author)

  1. Bittersweet: Real-Time, Dynamic Changes in Blood Glucose Levels during an Acute Ozone Exposure in Rats

    Science.gov (United States)

    In humans and rats, acute exposures to ozone have been shown to activate the sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenal axes to induce multi-organ metabolic alterations including impaired glucose homeostasis. These findings have largely been gleaned from on...

  2. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development.

    Science.gov (United States)

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-11-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions - pollen originating from plants raised in charcoal-Purafil(®) filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol(-1) O3 (10 h d(-1)) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit - a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during 'risk assessment' exercises. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Ozone Exposure-Response in Field Grown Soybean: Characterizing Intraspecific Variability of Physiology and Biochemistry

    Science.gov (United States)

    Crop losses due to rising tropospheric ozone concentrations ([ozone]) in 2000 were estimated to cost $1.8 to $3.9 billion in the U.S. and $3.0 to $5.5 billion in China, and are expected to grow with the predicted 25% increase in background [ozone] over the next 30 to 50 years. This challenge provide...

  4. Exposure- and flux-based assessment of ozone risk to sugarcane plants

    Science.gov (United States)

    Moura, Bárbara Baêsso; Hoshika, Yasutomo; Ribeiro, Rafael Vasconcelos; Paoletti, Elena

    2018-03-01

    Ozone (O3) is a toxic oxidative air pollutant, with significant detrimental effects on crops. Sugarcane (Saccharum spp.) is an important crop with no O3 risk assessment performed so far. This study aimed to assess O3 risk to sugarcane plants by using exposure-based indices (AOT40 and W126) based on O3 concentrations in the air, and the flux-based index (PODy, where y is a threshold of uptake) that considers leaf O3 uptake and the influence of environmental conditions on stomatal conductance (gsto). Two sugarcane genotypes (IACSP94-2094 and IACSP95-5000) were subjected to a 90-day Free-Air Controlled Experiment (FACE) exposure at three levels of O3 concentrations: ambient (Amb); Amb x1.2; and Amb x1.4. Total above-ground biomass (AGB), stalk biomass (SB) and leaf biomass (LB) were evaluated and the potential biomass production in a clean air was estimated by assuming a theoretical clean atmosphere at 10 ppb as 24 h O3 average. The Jarvis-type multiplicative algorithm was used to parametrize gsto including environmental factors i.e. air temperature, light intensity, air vapor pressure deficit, and minimum night-time temperature. Ozone exposure caused a negative impact on AGB, SB and LB. The O3 sensitivity of sugarcane may be related to its high gsto (∼535 mmol H2O m-2 s-1). As sugarcane is adapted to hot climate conditions, gsto was restricted when the current minimum air temperature (Tmin) was below ∼14 °C and the minimum night-time air temperature of the previous day (Tnmin) was below ∼7.5 °C. The flux-based index (PODy) performed better than the exposure-based indices in estimating O3 effect on biomass losses. We recommend a y threshold of 2 nmol m-2 s-1 to incorporate O3 effects on both AGB and SB and 1 nmol m-2 s-1 on LB. In order not to exceed 4% reduction in the growth of these two sugarcane genotypes, we recommend the following critical levels: 1.09 and 1.04 mmol m-2 POD2 for AGB, 0.91 and 0.96 mmol m-2 POD2 for SB, and 3.00 and 2.36 mmol m-2 POD1 for

  5. Changes in the carbon dioxide expirogram in response to ozone exposure

    International Nuclear Information System (INIS)

    Taylor, Adekemi B.; Lee, Genea M.; Nellore, Kavitha; Ben-Jebria, Abdellaziz; Ultman, James S.

    2006-01-01

    The objectives of this study were to quantify pulmonary responses to ozone (O 3 ) exposure by parameters computed from the carbon dioxide expirogram and to compare these responses to decrements in forced expired spirometry. Anatomical dead space (V D ) was determined from the pure dead space and transition regions of the expirogram. Four alternative parameters were computed from the alveolar plateau: slope (S), normalized slope (NS), peripheral cross-sectional area (A P ) and well-mixed peripheral volume (V MP ). Forty-seven healthy nonsmokers (25 men and 22 women) participated in two research sessions in which they exercised on a cycle ergometer for 1 h while orally inhaling either room air at a minute ventilation of 30.6 ± 3.6 L or room air mixed with 0.252 ± 0.029 ppm O 3 at a minute ventilation of 29.9 ± 3.7 L. Carbon dioxide expirograms were measured before exposure, 10 min after exposure and 70 min after exposure. Percent changes (mean ± SD) in expirogram parameters were significant (P ≤ 0.002) at both 10 and 70 min after O 3 exposure: V D (-4.2 ± 5.1, -3.3 ± 6.9), S(16.4 ± 17.9, +15.1 ± 20.2), NS(17.5 ± 15.4, +15.9 ± 19.2), A P (-8.1 ± 7.6, -7.7 ± 9.8) and V MP (-15.4 ± 13.0, -13.0 ± 15.2). Percent decrements of forced expired volume in one second (FEV 1 ) were also significant at both 10 min (-13.3 ± 13.4) and 70 min (-11.1 ± 9.2) following O 3 exposure. Changes in the expirogram as well as decrements in FEV 1 were not significant at either time point after air exposure. Thus, the CO 2 expirogram is useful for characterizing the effect of O 3 exposure on gas transport, and for supplementing forced expired spirometry that is frequently used to quantify lung mechanics

  6. Atrophic rhinitis and other nasal lesions induced by a 1-month exposure of F344 rats to 0.25 or 0.5 ppm ozone

    International Nuclear Information System (INIS)

    Hotchkiss, J.A.; Harkema, J.R.; Wacnik, P.W.

    1994-01-01

    Ozone, the principal oxidant pollutant of photochemical smog, is a common inhaled toxicant for metropolitan area residents. The effects of acute and chronic ozone exposure on inflammatory cell influx, hyperplasia, and secretory cell metaplasia within the surface epithelium lining rat nasal airways have previously been reported. On the other hand, there is a paucity of data describing the effects of ozone exposure on the subepithelial tissues (i.e., lamina propria and bone) of nasal turbinates. However, recently, a significant decrease in nasal turbinate bone area in rats chronically exposed (20 mo) to 1 ppm ozone was reported. The purpose of the present study was to examine the effects of a 1-mo ozone exposure on subepithelial tissue compartments of maxilloturbinates in the anterior nasal cavity of rats

  7. Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

    Science.gov (United States)

    Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

    2003-11-01

    The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed.

  8. The effect of chronic ozone exposure on the activation of endoplasmic reticulum stress and apoptosis in rat hippocampus

    Directory of Open Access Journals (Sweden)

    Erika Rodríguez-Martínez

    2016-10-01

    Full Text Available The chronic exposure to low doses of ozone, like in environmental pollution, leads to a state of oxidative stress, which has been proposed to contribute to neurodegenerative disorders, including Alzheimer's disease. It induces an increase of calcium in the endoplasmic reticulum (ER, which produces ER stress. On the other hand, different studies show that, in diseases such as Alzheimer’s, there exist disturbances in protein folding where ER plays an important role. The objective of this study was to evaluate the state of chronic oxidative stress on ER stress and its relationship with apoptotic death in the hippocampus of rats exposed to low doses of ozone. We used 108 male Wistar rats randomly divided into five groups. The groups received one of the following treatments: 1 Control (air, 2 Ozone (O3 7 days, 3 O3 15 days, 4 O3 30 days, 5 O3 60 days, and 6 O3 90 days. Two hours after each treatment, the animals were sacrificed and the hippocampus was extracted. Afterwards, the tissue was processed for western blot and immunohistochemistry using the following antibodies: ATF6, GRP8 and caspase 12. It was also performed TUNEL assay and electronic microscopy. Our results show an increase in ATF6, GRP78 and caspase 12 as well as ER ultrastructural alterations and an increase of TUNEL positive cells after 60 and 90 days of exposure to ozone. With the obtained results, we can conclude that oxidative stress induced by chronic exposure to low doses of ozone leads to ER stress. ER stress activates ATF6 inducing the increase of GRP78 in the cytoplasm, which leads to the increase in the nuclear translocation of ATF6. Finally, the translocation creates a vicious cycle that, together with the activation of the cascade for apoptotic cell death, contributes to the maintenance of ER stress. These events potentially contribute in the neurodegeneration processes in diseases like Alzheimer’s Disease.

  9. Ozone Enhances Diesel Exhaust Particles (DEP-Induced Interleukin-8 (IL-8 Gene Expression in Human Airway Epithelial Cells through Activation of Nuclear Factors- κB (NF-κB and IL-6 (NF-IL6

    Directory of Open Access Journals (Sweden)

    James Kelley

    2005-12-01

    Full Text Available Ozone, a highly reactive oxidant gas is a major component of photochemical smog. As an inhaled toxicant, ozone induces its adverse effects mainly on the lung. Inhalation of particulate matter has been reported to cause airway inflammation in humans and animals. Furthermore, epidemiological evidence has indicated that exposure to particulate matter (PM2.5-10, including diesel exhaust particles (DEP has been correlated with increased acute and chronic respiratory morbidity and exacerbation of asthma. Previously, exposure to ozone or particulate matter and their effect on the lung have been addressed as separate environmental problems. Ozone and particulate matter may be chemically coupled in the ambient air. In the present study we determined whether ozone exposure enhances DEP effect on interleukin-8 (IL-8 gene expression in human airway epithelial cells. We report that ozone exposure (0.5 ppm x 1 hr significantly increased DEP-induced IL-8 gene expression in A549 cells (117 ± 19 pg/ml, n = 6, p < 0.05 as compared to cultures treated with DEP (100 μg/ml x 4 hr alone (31 ± 3 pg/ml, n = 6, or cultures exposed to purified air (24 ± 6 pg/ml, n = 6. The increased DEP-induced IL-8 gene expression following ozone exposure was attributed to ozone-induced increase in the activity of the transcription factors NF-κB and NF-IL6. The results of the present study indicate that ozone exposure enhances the toxicity of DEP in human airway epithelial cells by augmenting IL-8 gene expression, a potent chemoattractant of neutrophils in the lung.

  10. Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

    Science.gov (United States)

    Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

    2014-02-01

    The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (P<0.0001). In a nutshell, ozone enhanced the remineralizing potential of nanohydroxyapatite, and laser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

  11. SPIROMETRIC RESPONSE TO OZONE (O3) IN YOUNG ADULTS AS A FUNCTION OF BODY MAASS INDEX (BMI)

    Science.gov (United States)

    Recent studies in murine models of obesity have shown enhanced responsiveness to ozone in obese vs. lean mice. To assess whether previous human ozone exposure data from our laboratory support an effect of BMI on the spirometric response to ozone we analyzed the post-O3 percent de...

  12. Enhanced nitrogen deposition exacerbates the negative effect of increasing background ozone in Dactylis glomerata, but not Ranunculus acris

    Energy Technology Data Exchange (ETDEWEB)

    Wyness, Kirsten, E-mail: kirnes@ceh.ac.uk [Centre for Ecology and Hydrology (CEH), Environment Centre Wales, Deiniol Road, Bangor LL57 2UW (United Kingdom); Newcastle Institute for Research on the Environment and Sustainability - NIRES, Devonshire Building, Newcastle University, Newcastle Upon Tyne NE1 7RU (United Kingdom); Mills, Gina; Jones, Laurence [Centre for Ecology and Hydrology (CEH), Environment Centre Wales, Deiniol Road, Bangor LL57 2UW (United Kingdom); Barnes, Jeremy D. [Newcastle Institute for Research on the Environment and Sustainability - NIRES, Devonshire Building, Newcastle University, Newcastle Upon Tyne NE1 7RU (United Kingdom); Jones, Davey L. [School of the Environment and Natural Resources, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom)

    2011-10-15

    The combined impacts of simulated increased nitrogen (N) deposition (75 kg N ha{sup -1} yr{sup -1}) and increasing background ozone (O{sub 3}) were studied using two mesotrophic grassland species (Dactylis glomerata and Ranunculus acris) in solardomes, by means of eight O{sub 3} treatments ranging from 15.5 ppb to 92.7 ppb (24 h average mean). A-C{sub i} curves were constructed for each species to gauge effects on photosynthetic efficiency and capacity, and effects on biomass partitioning were determined after 14 weeks. Increasing the background concentration of O{sub 3} reduced the healthy above ground and root biomass of both species, and increased senesced biomass. N fertilisation increased biomass production in D. glomerata, and a significantly greater than additive effect of O{sub 3} and N on root biomass was evident. In contrast, R. acris biomass was not affected by high N. The study shows the combined effects of these pollutants have differential implications for carbon allocation patterns in common grassland species. - Highlights: > Dactylis glomerata and Ranunculus acris enhanced senescence with increasing O{sub 3}. > Ozone effects on root biomass were larger than on shoot biomass in both species. > N deposition exacerbated the negative O{sub 3} effect on D. glomerata root biomass. > Inter-specific differences in the response to O{sub 3} and N combined exposure. - Synergistic effects of elevated O{sub 3} and N were observed in below ground C-partitioning in the grass Dactylis glomerata, but not in the forb Ranunculus acris.

  13. Ambient Ozone Exposure in Czech Forests: A GIS-Based Approach to Spatial Distribution Assessment

    Science.gov (United States)

    Hůnová, I.; Horálek, J.; Schreiberová, M.; Zapletal, M.

    2012-01-01

    Ambient ozone (O3) is an important phytotoxic pollutant, and detailed knowledge of its spatial distribution is becoming increasingly important. The aim of the paper is to compare different spatial interpolation techniques and to recommend the best approach for producing a reliable map for O3 with respect to its phytotoxic potential. For evaluation we used real-time ambient O3 concentrations measured by UV absorbance from 24 Czech rural sites in the 2007 and 2008 vegetation seasons. We considered eleven approaches for spatial interpolation used for the development of maps for mean vegetation season O3 concentrations and the AOT40F exposure index for forests. The uncertainty of maps was assessed by cross-validation analysis. The root mean square error (RMSE) of the map was used as a criterion. Our results indicate that the optimal interpolation approach is linear regression of O3 data and altitude with subsequent interpolation of its residuals by ordinary kriging. The relative uncertainty of the map of O3 mean for the vegetation season is less than 10%, using the optimal method as for both explored years, and this is a very acceptable value. In the case of AOT40F, however, the relative uncertainty of the map is notably worse, reaching nearly 20% in both examined years. PMID:22566757

  14. Effect of ozone exposure on maximal airway narrowing in non-asthmatic and asthmatic subjects

    NARCIS (Netherlands)

    Hiltermann, T J; Stolk, J; Hiemstra, P S; Fokkens, P H; Rombout, P J; Sont, J K; Sterk, P J; Dijkman, J H

    1995-01-01

    1. Ozone is a major constituent of air pollution in the summer. Epidemiological studies have demonstrated that there is an increase in hospital admissions for respiratory diseases 1 day after peak levels of ambient ozone. This may be due to an increase in the responsiveness of the airways to

  15. Long-term exposure to ambient ozone and mortality: a quantitative systematic review and meta-analysis of evidence from cohort studies.

    Science.gov (United States)

    Atkinson, R W; Butland, B K; Dimitroulopoulou, C; Heal, M R; Stedman, J R; Carslaw, N; Jarvis, D; Heaviside, C; Vardoulakis, S; Walton, H; Anderson, H R

    2016-02-23

    While there is good evidence for associations between short-term exposure to ozone and a range of adverse health outcomes, the evidence from narrative reviews for long-term exposure is suggestive of associations with respiratory mortality only. We conducted a systematic, quantitative evaluation of the evidence from cohort studies, reporting associations between long-term exposure to ozone and mortality. Cohort studies published in peer-reviewed journals indexed in EMBASE and MEDLINE to September 2015 and PubMed to October 2015 and cited in reviews/key publications were identified via search strings using terms relating to study design, pollutant and health outcome. Study details and estimate information were extracted and used to calculate standardised effect estimates expressed as HRs per 10 ppb increment in long-term ozone concentrations. 14 publications from 8 cohorts presented results for ozone and all-cause and cause-specific mortality. We found no evidence of associations between long-term annual O3 concentrations and the risk of death from all causes, cardiovascular or respiratory diseases, or lung cancer. 4 cohorts assessed ozone concentrations measured during the warm season. Summary HRs for cardiovascular and respiratory causes of death derived from 3 cohorts were 1.01 (95% CI 1.00 to 1.02) and 1.03 (95% CI 1.01 to 1.05) per 10 ppb, respectively. Our quantitative review revealed a paucity of independent studies regarding the associations between long-term exposure to ozone and mortality. The potential impact of climate change and increasing anthropogenic emissions of ozone precursors on ozone levels worldwide suggests further studies of the long-term effects of exposure to high ozone levels are warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. Spatiotemporal prediction of daily ambient ozone levels across China using random forest for human exposure assessment.

    Science.gov (United States)

    Zhan, Yu; Luo, Yuzhou; Deng, Xunfei; Grieneisen, Michael L; Zhang, Minghua; Di, Baofeng

    2018-02-01

    In China, ozone pollution shows an increasing trend and becomes the primary air pollutant in warm seasons. Leveraging the air quality monitoring network, a random forest model is developed to predict the daily maximum 8-h average ozone concentrations ([O 3 ] MDA8 ) across China in 2015 for human exposure assessment. This model captures the observed spatiotemporal variations of [O 3 ] MDA8 by using the data of meteorology, elevation, and recent-year emission inventories (cross-validation R 2  = 0.69 and RMSE = 26 μg/m 3 ). Compared with chemical transport models that require a plenty of variables and expensive computation, the random forest model shows comparable or higher predictive performance based on only a handful of readily-available variables at much lower computational cost. The nationwide population-weighted [O 3 ] MDA8 is predicted to be 84 ± 23 μg/m 3 annually, with the highest seasonal mean in the summer (103 ± 8 μg/m 3 ). The summer [O 3 ] MDA8 is predicted to be the highest in North China (125 ± 17 μg/m 3 ). Approximately 58% of the population lives in areas with more than 100 nonattainment days ([O 3 ] MDA8 >100 μg/m 3 ), and 12% of the population are exposed to [O 3 ] MDA8 >160 μg/m 3 (WHO Interim Target 1) for more than 30 days. As the most populous zones in China, the Beijing-Tianjin Metro, Yangtze River Delta, Pearl River Delta, and Sichuan Basin are predicted to be at 154, 141, 124, and 98 nonattainment days, respectively. Effective controls of O 3 pollution are urgently needed for the highly-populated zones, especially the Beijing-Tianjin Metro with seasonal [O 3 ] MDA8 of 140 ± 29 μg/m 3 in summer. To the best of the authors' knowledge, this study is the first statistical modeling work of ambient O 3 for China at the national level. This timely and extensively validated [O 3 ] MDA8 dataset is valuable for refining epidemiological analyses on O 3 pollution in China. Copyright © 2017 Elsevier Ltd. All rights

  17. Growth response of seedlings of six Betula pubescens Ehrh. provenances to six ozone exposure regimes

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, L.M. [Agricultural Univ. of Norway, Aas (Norway). Dept. of Horticulture and Crop Science

    1998-07-01

    Seedlings of six provenances of Betula pubescens Ehrh. from different latitudes (59-70 deg N) were grown under six ozone exposure regimes by combining different concentrations and daily exposure periods. The different treatments at increasing O{sub 3} exposure over 40 nmol/mol (AOT40 given in parentheses) were: 19 nmol mol{sup -1}/24 h day{sup -1} (0.1 {mu}mol/mol-h), 42 nmol mol{sup -1}/12 h day{sup -1} (2.5 {mu}mol/mol-h), 44 nmol mol{sup -1}/24 h day{sup -1} (7.1 {mu}mol/mol-h), 76 nmol mol{sup -1}/6 day{sup -1} (9.4 {mu}mol/mol-h), 75 nmol mol{sup -1}/12 h day{sup -1} (17.8 {mu}mol/mol{sup -1}) and 116 nmol mol{sup -1}/6 h day{sup -1} (19.8 {mu}mol/mol{sup -1}) for 40 days at a 24 h day{sup -1} photoperiod in growth chambers placed in a greenhouse. The effect of increasing the O{sub 3} exposure from 19 nmol mol{sup -1}/24 h to 42 nmol mol{sup -1}/12 h was a decrease in root but not shoot dry weight. A further increase in the exposure to 44 nmol mol{sup -1}/24 h also decreased the shoot dry weight. An increase in the O{sub 3} concentration to 75 and 116 nmol mol{sup -1} further decreased shoot and root dry weights. A moderate O{sub 3} exposure (42 nmol mol{sup -1}/12 h) increased the plant height and leaf size, while a further increase in O{sub 3} concentration and exposure time decreased both of these variables. The birch provenances generally had a similar response to the O{sub 3} treatments. The accumulated O{sub 3} exposure over the 0, 10, 20, 30, 40 and 50 nmol mol{sup -1} concentrations (AOT0, AOT10, AOT20, AOT30, AOT40 and AOT50, respectively) was calculated for all O{sub 3} treatments. The shoot and root dry weights were correlated best with AOT40 and AOT30, and were estimated to decrease by 10% at an AOT40 of 7.0 and 5.5 {mu}mol mol{sup -1}-h, respectively. The development of O{sub 3} injury (yellow stipples/chlorosis) was most marked when correlated with AOT40 26 refs, 6 figs, 1 tab

  18. Pre-exposure to nitric oxide modulates the effect of ozone on oxidative defenses and volatile emissions in lima bean

    International Nuclear Information System (INIS)

    Souza, Silvia R.; Blande, James D.; Holopainen, Jarmo K.

    2013-01-01

    The roles that ozone and nitric oxide (NO), the chief O 3 precursor, play in the antioxidative balance and inducible volatile emissions of lima bean were assessed. Exposure to O 3 inhibited APX, CAT, and GR, decreased GSH content and induced emissions of (E)-β-ocimene, limonene, 1,8-cineole, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene (E)-DMNT, 2-butanone and nonanal. O 3 did not induce emissions of (E)-β-caryophyllene and appeared to reduce the antioxidative capacity of plants to a greater extent than NO and NO followed by O 3 (NO/O 3 ) treatments. There were significant differences in emissions of (E)-β-ocimene and linalool between NO/O 3 treated plants and controls, but no differences in antioxidant concentrations. A model to explain the relationships between the ascorbate–glutathione cycle and O 3 and NO inducible volatiles was proposed. Our findings suggest that prior exposure to NO modulates the oxidative effect of ozone by the process of cross-tolerance, which might regulate the antioxidative system and induction of volatile organic compounds. -- Highlights: •NO and O 3 disturb antioxidant defenses and cause lipid peroxidation in lima bean plants. •Exposure to NO before exposure to O 3 does not alter the antioxidant defenses and malondialdehyde levels. •The total sum of induced volatiles is reduced in plants that are exposed to NO and then O 3 . •The antioxidant system and induced VOC emission were balanced by pre-exposure to NO before O 3 . -- Capsule: Nitric oxide modulates the ozone-induced oxidative stress in lima bean by cross-tolerance effect

  19. Assessment of rice yield loss due to exposure to ozone pollution in Southern Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Danh, Ngo Thanh; Huy, Lai Nguyen; Oanh, Nguyen Thi Kim, E-mail: kimoanh@ait.ac.th

    2016-10-01

    The study domain covered the Eastern region of Southern of Vietnam that includes Ho Chi Minh City (HCMC) and five other provinces. Rice production in the domain accounted for 13% of the national total with three crop cycles per year. We assessed ozone (O{sub 3}) induced rice production loss in the domain for 2010 using simulated hourly surface O{sub 3} concentrations (WRF/CAMx; 4 km resolution). Simulated O{sub 3} was higher in January–February (largely overlaps the first crop) and September–December (third crop), and lower in March–June (second crop). Spatially, O{sub 3} was higher in downwind locations of HCMC and were comparable with observed data. Relative yield loss (RYL) was assessed for each crop over the respective growing period (105 days) using three metrics: AOT40, M7 and flux-based O{sub 3} dose of POD{sub 10}. Higher RYL was estimated for the downwind of HCMC. Overall, the rice production loss due to O{sub 3} exposure in the study domain in 2010 was the highest for the first crop (up to 25,800 metric tons), the second highest for the third crop (up to 21,500 tons) and the least for the second crop (up to 6800 tons). The low RYL obtained for the second crop by POD{sub 10} may be due to the use of a high threshold value (Y = 10 nmol m{sup −2} s{sup −1}). Linear regression between non-null radiation POD{sub 0} and POD{sub 10} had similar slopes for the first and third crop when POD{sub 0} was higher and very low slope for the second crop when POD{sub 0} was low. The results of this study can be used for the rice crop planning to avoid the period of potential high RYL due to O{sub 3} exposure. - Highlights: • Simulated O{sub 3} was used to assess rice yield loss in a domain of Southern Vietnam. • Exposure metrics of AOT40, M7, POD{sub 0} and POD{sub 10} were considered. • POD{sub 10} gave the highest rice production loss. • Higher production loss was found downwind of Ho Chi Minh City.

  20. Assessment of rice yield loss due to exposure to ozone pollution in Southern Vietnam

    International Nuclear Information System (INIS)

    Danh, Ngo Thanh; Huy, Lai Nguyen; Oanh, Nguyen Thi Kim

    2016-01-01

    The study domain covered the Eastern region of Southern of Vietnam that includes Ho Chi Minh City (HCMC) and five other provinces. Rice production in the domain accounted for 13% of the national total with three crop cycles per year. We assessed ozone (O 3 ) induced rice production loss in the domain for 2010 using simulated hourly surface O 3 concentrations (WRF/CAMx; 4 km resolution). Simulated O 3 was higher in January–February (largely overlaps the first crop) and September–December (third crop), and lower in March–June (second crop). Spatially, O 3 was higher in downwind locations of HCMC and were comparable with observed data. Relative yield loss (RYL) was assessed for each crop over the respective growing period (105 days) using three metrics: AOT40, M7 and flux-based O 3 dose of POD 10 . Higher RYL was estimated for the downwind of HCMC. Overall, the rice production loss due to O 3 exposure in the study domain in 2010 was the highest for the first crop (up to 25,800 metric tons), the second highest for the third crop (up to 21,500 tons) and the least for the second crop (up to 6800 tons). The low RYL obtained for the second crop by POD 10 may be due to the use of a high threshold value (Y = 10 nmol m −2 s −1 ). Linear regression between non-null radiation POD 0 and POD 10 had similar slopes for the first and third crop when POD 0 was higher and very low slope for the second crop when POD 0 was low. The results of this study can be used for the rice crop planning to avoid the period of potential high RYL due to O 3 exposure. - Highlights: • Simulated O 3 was used to assess rice yield loss in a domain of Southern Vietnam. • Exposure metrics of AOT40, M7, POD 0 and POD 10 were considered. • POD 10 gave the highest rice production loss. • Higher production loss was found downwind of Ho Chi Minh City.

  1. Enhanced ozonation degradation of di-n-butyl phthalate by zero-valent zinc in aqueous solution: Performance and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Gang [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710050 (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Wang, Sheng-Jun [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Beijing General Municipal Engineering Design and Research Institute, Beijing 100082 (China); Ma, Jun, E-mail: majun@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Huang, Ting-Lin [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710050 (China); Liu, Zheng-Qian, E-mail: liuzhengqian@gmail.com [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhao, Lei [School of Civil Engineering, Harbin Institute of Technology, Harbin 150090 (China); Su, Jun-Feng [State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), Tsinghua University, Beijing 100084 (China)

    2014-01-30

    Highlights: • ZVZ showed an obvious enhanced effect on DBP degradation in ozonation. • The recycling use of ZVZ resulted in the enhancement of DBP degradation. • The formed ZnO and reactive intermediates were responsible for the enhanced effect. • The enhanced effect on DBP degradation by ZVZ was also effective in actual waters. -- Abstract: Enhanced ozonation degradation of di-n-butyl phthalate (DBP) by zero-valent zinc (ZVZ) has been investigated using a semi-continuous reactor in aqueous solution. The results indicated that the combination of ozone (O{sub 3}) and ZVZ showed an obvious synergetic effect, i.e. an improvement of 54.8% on DBP degradation was obtained by the O{sub 3}/ZVZ process after 10 min reaction compared to the cumulative effect of O{sub 3} alone and O{sub 2}/ZVZ. The degradation efficiency of DBP increased gradually with the increase of ZVZ dosage, enhanced as solution pH increasing from 2.0 to 10.0, and more amount of DBP was degraded with the initial concentration of DBP arising from 0.5 to 2.0 mg L{sup −1}. Recycling use of ZVZ resulted in the enhancement of DBP degradation, because the newly formed zinc oxide took part in the reaction. The mechanism investigation demonstrated that the enhancement effect was attributed to the introduction of ZVZ, which could promote the utilization of O{sub 3}, enhance the formation of superoxide radical by reducing O{sub 2} via one-electron transfer, accelerate the production of hydrogen peroxide and the generation of hydroxyl radical. Additionally, the newly formed zinc oxide on ZVZ surface also contributed to the enhancement of DBP degradation in the recycling use of ZVZ. Most importantly, the O{sub 3}/ZVZ process was also effective in enhanced ozonation degradation of DBP under the background of actual waters.

  2. Pulmonary sensitivity to ozone exposure in sedentary versus chronically trained, female rats

    Data.gov (United States)

    U.S. Environmental Protection Agency — Pulmonary effects to ozone with rats that have chronically exercised or have been continuously sedentary. Also includes body composition of both groups throughout...

  3. Suppression and recovery of the alveolar macrophage phagocytic system during continuous exposure to 0. 5 ppm ozone

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, M.I.; Hmieleski, R.R.; Stafford, E.A.; Jakab, G.J. (Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD (USA))

    1991-05-01

    Short-term exposures to ozone (O3) are known to impair pulmonary antibacterial defenses and alveolar macrophage (AM) phagocytosis in a dose-related manner. To determine the effect of prolonged O3 exposure, Swiss mice were exposed continuously to 0.5 ppm O3. At 1, 3, 7, and 14 days, intrapulmonary killing was assessed by inhalation challenge with Staphylococcus aureus or Proteus mirabilis and by comparing the number of viable bacteria remaining in the lungs at 4 h between O3-exposed and control animals. To evaluate the effects of O3 on the functional capacity of the AMs, Fc-receptor mediated phagocytosis was assessed. Ozone exposure impaired the intrapulmonary killing of S. aureus at 1 and 3 days; however, with prolonged exposure, the bactericidal capacity of the lungs returned to normal. This trend of an initial suppression followed by recovery was reflected in the phagocytic capacity of the AMs. In contrast to S. aureus, when P. mirabilis was used as the challenge organism, O3 exposure had no suppressive effect on pulmonary bactericidal activity, which correlated with an increase in the phagocytic cell population in the lungs. Morphologic examination of the lavaged macrophages showed that after 1 day of O3 exposure, the AMs were more foamy, and contained significantly more vacuoles. There was also a significant increase in binucleated cells at 3 days. These studies demonstrate that continuous exposure to O3 modulates AM-dependent lung defenses and points to the importance of the challenge organism and exposure protocol in establishing the adverse effect of O3.

  4. Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

    International Nuclear Information System (INIS)

    Sanz, J.; Bermejo, V.; Muntifering, R.; Gonzalez-Fernandez, I.; Gimeno, B.S.; Elvira, S.; Alonso, R.

    2011-01-01

    An assessment of the effects of tropospheric ozone (O 3 ) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O 3 and three N levels. Increased O 3 exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O 3 -induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of herbaceous vegetation. - Research highlights: → Forage quality (foliar protein and fiber content) and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima. → The effects of N supplementation depended on meteorological conditions and plant physiological activity. → Increase in nitrogen supplementation counterbalanced the O 3 -induced increase in senescence biomass. → Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

  5. γδ T cells are required for pulmonary IL-17A expression after ozone exposure in mice: role of TNFα.

    Directory of Open Access Journals (Sweden)

    Joel A Mathews

    Full Text Available Ozone is an air pollutant that causes pulmonary symptoms. In mice, ozone exposure causes pulmonary injury and increases bronchoalveolar lavage macrophages and neutrophils. We have shown that IL-17A is important in the recruitment of neutrophils after subacute ozone exposure (0.3 ppm for 24-72 h. We hypothesized that γδ T cells are the main producers of IL-17A after subacute ozone. To explore this hypothesis we exposed wildtype mice and mice deficient in γδ T cells (TCRδ-/- to ozone or room air. Ozone-induced increases in BAL macrophages and neutrophils were attenuated in TCRδ-/- mice. Ozone increased the number of γδ T cells in the lungs and increased pulmonary Il17a mRNA expression and the number of IL-17A+ CD45+ cells in the lungs and these effects were abolished in TCRδ-/- mice. Ozone-induced increases in factors downstream of IL-17A signaling, including G-CSF, IL-6, IP-10 and KC were also decreased in TCRδ-/- versus wildtype mice. Neutralization of IL-17A during ozone exposure in wildtype mice mimicked the effects of γδ T cell deficiency. TNFR2 deficiency and etanercept, a TNFα antagonist, also reduced ozone-induced increases in Il17a mRNA, IL-17A+ CD45+ cells and BAL G-CSF as well as BAL neutrophils. TNFR2 deficient mice also had decreased ozone-induced increases in Ccl20, a chemoattractant for IL-17A+ γδ T cells. Il17a mRNA and IL-17A+ γδ T cells were also lower in obese Cpefat versus lean WT mice exposed to subacute ozone, consistent with the reduced neutrophil recruitment observed in the obese mice. Taken together, our data indicate that pulmonary inflammation induced by subacute ozone requires γδ T cells and TNFα-dependent recruitment of IL-17A+ γδ T cells to the lung.

  6. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  7. Fe-Mn bi-metallic oxides loaded on granular activated carbon to enhance dye removal by catalytic ozonation.

    Science.gov (United States)

    Tang, Shoufeng; Yuan, Deling; Zhang, Qi; Liu, Yameng; Zhang, Qi; Liu, Zhengquan; Huang, Haiming

    2016-09-01

    A Fe-Mn bi-metallic oxide supported on granular activated carbon (Fe-Mn GAC) has been fabricated by an impregnation-desiccation method and tested in the catalytic ozonation of methyl orange (MO) degradation and mineralization. X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy characterizations revealed that Fe-Mn oxides were successfully loaded and uniformly distributed on the GAC, and nitrogen adsorption isotherms showed that the supported GAC retained a large surface area and a high pore volume compared with the pristine GAC. The catalytic activity was systematically assessed by monitoring the MO removal efficiencies at different operational parameters, such as catalyst dosage, initial solution pH, and ozone flow rate. The Fe-Mn GAC exhibited better catalytic activity relative to ozone alone and GAC alone, improving the TOC removal by 24.5 and 11.5 % and COD removal by 13.6 and 7.3 %, respectively. The reusability of the hybrid was examined over five consecutive cyclic treatments. The Fe-Mn GAC catalytic activity was only a slight loss in the cycles, showing good stability. The addition of Na2CO3 as hydroxyl radicals (•OH) scavengers proved that the catalytic ozonation mechanism was the enhanced generation of •OH by the Fe-Mn GAC. The above results render the Fe-Mn GAC an industrially promising candidate for catalytic ozonation of dye contaminant removal.

  8. Biomarkers of oxidative stress study V: ozone exposure of rats and its effect on lipids, proteins, and DNA in plasma and urine.

    Science.gov (United States)

    Kadiiska, Maria B; Basu, Samar; Brot, Nathan; Cooper, Christopher; Saari Csallany, A; Davies, Michael J; George, Magdalene M; Murray, Dennis M; Jackson Roberts, L; Shigenaga, Mark K; Sohal, Rajindar S; Stocker, Roland; Van Thiel, David H; Wiswedel, Ingrid; Hatch, Gary E; Mason, Ronald P

    2013-08-01

    Ozone exposure effect on free radical-catalyzed oxidation products of lipids, proteins, and DNA in the plasma and urine of rats was studied as a continuation of the international Biomarker of Oxidative Stress Study (BOSS) sponsored by NIEHS/NIH. The goal was to identify a biomarker for ozone-induced oxidative stress and to assess whether inconsistent results often reported in the literature might be due to the limitations of the available methods for measuring the various types of oxidative products. The time- and dose-dependent effects of ozone exposure on rat plasma lipid hydroperoxides, malondialdehyde, F2-isoprostanes, protein carbonyls, methionine oxidation, and tyrosine- and phenylalanine oxidation products, as well as urinary malondialdehyde and F2-isoprostanes were investigated with various techniques. The criterion used to recognize a marker in the model of ozone exposure was that a significant effect could be identified and measured in a biological fluid seen at both doses at more than one time point. No statistically significant differences between the experimental and the control groups at either ozone dose and time point studied could be identified in this study. Tissue samples were not included. Despite all the work accomplished in the BOSS study of ozone, no available product of oxidation in biological fluid has yet met the required criteria of being a biomarker. The current negative findings as a consequence of ozone exposure are of great importance, because they document that in complex systems, as the present in vivo experiment, the assays used may not provide meaningful data of ozone oxidation, especially in human studies. Published by Elsevier Inc.

  9. Quantification of ozone exposure- and stomatal uptake-yield response relationships for soybean in Northeast China.

    Science.gov (United States)

    Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Liu, Xiaobing; Hu, Enzhu

    2017-12-01

    High ground-level O 3 is a new threat to agricultural production in Northeast China with the increasing ambient O 3 concentration. Little is known about its impacts on soybean production in this key agricultural region. Accumulated O 3 exposure-response and stomatal O 3 flux-response relationships were developed during two continuous growing seasons to evaluate O 3 -induced yield reduction of four typical soybean cultivars in Northeast China. Results showed that critical levels of AOT40 (accumulated hourly O 3 concentrations over a threshold of 40nmol·mol -1 ), SUM06 (sum of all hourly average O 3 concentrations over 0.06μmol·mol -1 ) and W126 (sum of O 3 concentrations weighted by a sigmoidal function) in relation to 5% reduction in relative seed yield were 4.2, 7.6 and 6.8μmol·mol -1 ·h, respectively. The effect of O 3 on plants was influenced by leaf position in canopy. An improved Jarvis stomatal conductance model including leaf (node) position fitted well with field measurements. The best linear relationship between stomatal O 3 flux and relative soybean yield was obtained when phytotoxic ozone dose was integrated over a threshold of 9.6nmol·m -2 ·s -1 (POD 9.6 ) to represent the detoxification capacity of soybean. POD 9.6 and the commonly used POD 6 in relation to 5% reduction in relative seed yield of soybean were 0.9mmol·m -2 and 1.8mmol·m -2 , respectively. O 3 concentrations above ~38nmol·mol -1 contributed to POD 9.6 and caused seed yield loss in soybean. Current annual yield loss of soybean at ambient O 3 was estimated to range between 23.4% and 30.2%. The O 3 dose-response relationships and corresponding thresholds obtained here will benefit regional O 3 risk assessment on soybean production in Northeast China. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Establishing a cause and effect relationship for ambient ozone exposure and tree growth in the forest: Progress and an experimental approach

    International Nuclear Information System (INIS)

    Manning, William J.

    2005-01-01

    Much has been written about the effects of ambient ozone on tree growth. Cause and effect has been established with seedlings in chambers. Results from multi-year studies with older tree seedlings, in open-top chambers, have been inconclusive, due to chamber effects. Extrapolation of results from chambers to trees in the forest is not possible. Predictive models for forest tree growth reductions caused by ozone have been developed, but not verified. Dendrochronological methods have been used to establish correlations between radial growth reductions in forest trees and ambient ozone exposure. The protective chemical ethylenediurea (EDU) has been used to protect tree seedlings from ozone injury. An experimental approach is advocated here that utilizes forest trees selected for sensitivity and non-sensitivity to ozone, dendrochronological methods, the protective chemical EDU, and monitoring data for ambient ozone, stomatal conductance, soil moisture potential, air temperature, PAR, etc. in long-term investigations to establish cause and effect relationships. - Progress is reviewed and an experimental approach is proposed to demonstrate a cause and effect relationship for ambient ozone and forest tree growth

  11. Stability enhancement of ozone-assisted laminar premixed Bunsen flames in nitrogen co-flow

    KAUST Repository

    Vu, Tran Manh; Won, Sanghee; Ombrello, Timothy M.; Cha, Min

    2014-01-01

    Ozone (O3) is known as one of the strongest oxidizers and therefore is widely used in many applications. Typically in the combustion field, a combination of non-thermal plasma and combustion systems have been studied focusing on the effects of ozone

  12. Cyanide Containing Wastewater Treatment by Ozone Enhanced Catalytic Oxidation over Diatomite Catalysts

    Directory of Open Access Journals (Sweden)

    Lin Mingguo

    2018-01-01

    Full Text Available Cyanide containing wastewater that discharged from gold mining process creates environmental problems due to the toxicity of cyanide. As one of the promising advanced oxidation process, catalytic oxidation with ozone is considered to be effective on the purification of cyanide. Diatomite, a natural mineral, was used as catalyst in this study. The effect of O3 dosage, salinity, initial cyanide concentration and initial pH condition were investigated. It was observed that the removal rate of cyanide was much higher in the catalytic oxidation with ozone process than the one in zone alone process. Alkaline condition was especially favorable for cyanide in catalytic oxidation with ozone. The ozone and catalytic oxidation with ozone were simulated by pseudo-first-order kinetics model. The apparent first-order rate constant contribution of the diatomite catalyst was 0.0757 min-1, and the contribution percentage was 65.77%.

  13. Effects of long-term ambient ozone exposure on biomass and wood traits in poplar treated with ethylenediurea (EDU)

    International Nuclear Information System (INIS)

    Carriero, G.; Emiliani, G.; Giovannelli, A.; Hoshika, Y.; Manning, W.J.; Traversi, M.L.; Paoletti, E.

    2015-01-01

    This is the longest continuous experiment where ethylenediurea (EDU) was used to protect plants from ozone (O 3 ). Effects of long-term ambient O 3 exposure (23 ppm h AOT40) on biomass of an O 3 sensitive poplar clone (Oxford) were examined after six years from in-ground planting. Trees were irrigated with either water or 450 ppm EDU. Above (−51%) and below-ground biomass (−47%) was reduced by O 3 although the effect was significant only for stem and coarse roots. Ambient O 3 decreased diameter of the lower stem, and increased moisture content along the stem of not-protected plants (+16%). No other change in the physical wood structure was observed. A comparison with a previous assessment in the same experiment suggested that O 3 effects on biomass partitioning to above-ground organs depend on the tree ontogenetic stage. The root/shoot ratios did not change, suggesting that previous short-term observations of reduced allocation to tree roots may be overestimated. - Highlights: • 6-y ambient O 3 exposure was investigated in a sensitive poplar clone. • EDU irrigation protected poplar against ambient O 3 exposure. • O 3 reduced biomass of roots and stem, but did not change biomass allocation. • O 3 decreased stem diameter only in the lower third of the stem. • O 3 increased moisture content of the wood along the stem. - Ozone exposure reduced lateral branching, leaves and roots in younger trees, and affected stem and roots in older trees, while shoot/root ratios did not change.

  14. Effects of chronic elevated ozone exposure on gas exchange responses of adult beech trees (Fagus sylvatica) as related to the within-canopy light gradient

    International Nuclear Information System (INIS)

    Kitao, Mitsutoshi; Loew, Markus; Heerdt, Christian; Grams, Thorsten E.E.; Haeberle, Karl-Heinz; Matyssek, Rainer

    2009-01-01

    The effects of elevated O 3 on photosynthetic properties in adult beech trees (Fagus sylvatica) were investigated in relation to leaf mass per area as a measure of the gradually changing, within-canopy light availability. Leaves under elevated O 3 showed decreased stomatal conductance at unchanged carboxylation capacity of Rubisco, which was consistent with enhanced δ 13 C of leaf organic matter, regardless of the light environment during growth. In parallel, increased energy demand for O 3 detoxification and repair was suggested under elevated O 3 owing to enhanced dark respiration. Only in shade-grown leaves, light-limited photosynthesis was reduced under elevated O 3 , this effect being accompanied by lowered F v /F m . These results suggest that chronic O 3 exposure primarily caused stomatal closure to adult beech trees in the field regardless of the within-canopy light gradient. However, light limitation apparently raised the O 3 sensitivity of photosynthesis and accelerated senescence in shade leaves. - Across leaf differentiation in adult beech crowns, elevated ozone acted through stomatal closure on gas exchange although enhancing photosynthetic sensitivity of shaded leaves

  15. Products of Ozone-initiated Chemistry during 4-hour Exposures of Human Subjects in a Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Tamás, Gyöngyi

    2006-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) was used to examine organic compounds in the air of a simulated aircraft cabin under four conditions: low ozone, low air exchange rate; low ozone, high air exchange rate; high ozone, low air exchange rate; high ozone, high air exchange rate....... The results showed large differences in the chemical composition of the cabin air between the low and high ozone conditions. These differences were more pronounced at the low air exchange condition....

  16. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers.

    Science.gov (United States)

    Tonneijck, A E G; Franzaring, J; Brouwer, G; Metselaar, K; Dueck, Th A

    2004-09-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l(-1) ozone (CF+25), non-filtered air (NF), non-filtered air plus 25 nl l(-1) ozone (NF+25) and non-filtered air plus 50 nl l(-1) ozone (NF+50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species.

  17. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, Th.A

    2004-09-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l{sup -1} ozone (CF + 25), non-filtered air (NF), non-filtered air plus 25 nl l{sup -1} ozone (NF + 25) and non-filtered air plus 50 nl l{sup -1} ozone (NF + 50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species.

  18. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    International Nuclear Information System (INIS)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, Th.A.

    2004-01-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l -1 ozone (CF + 25), non-filtered air (NF), non-filtered air plus 25 nl l -1 ozone (NF + 25) and non-filtered air plus 50 nl l -1 ozone (NF + 50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species

  19. Intermittent cold exposure enhances fat accumulation in mice.

    Directory of Open Access Journals (Sweden)

    Hyung Sun Yoo

    Full Text Available Due to its high energy consuming characteristics, brown adipose tissue (BAT has been suggested as a key player in energy metabolism. Cold exposure is a physiological activator of BAT. Intermittent cold exposure (ICE, unlike persistent exposure, is clinically feasible. The main objective of this study was to investigate whether ICE reduces adiposity in C57BL/6 mice. Surprisingly, we found that ICE actually increased adiposity despite enhancing Ucp1 expression in BAT and inducing beige adipocytes in subcutaneous white adipose tissue. ICE did not alter basal systemic insulin sensitivity, but it increased liver triglyceride content and secretion rate as well as blood triglyceride levels. Gene profiling further demonstrated that ICE, despite suppressing lipogenic gene expression in white adipose tissue and liver during cold exposure, enhanced lipogenesis between the exposure periods. Together, our results indicate that despite enhancing BAT recruitment, ICE in mice increases fat accumulation by stimulating de novo lipogenesis.

  20. Bayesian Hierarchical Distributed Lag Models for Summer Ozone Exposure and Cardio-Respiratory Mortality

    OpenAIRE

    Yi Huang; Francesca Dominici; Michelle Bell

    2004-01-01

    In this paper, we develop Bayesian hierarchical distributed lag models for estimating associations between daily variations in summer ozone levels and daily variations in cardiovascular and respiratory (CVDRESP) mortality counts for 19 U.S. large cities included in the National Morbidity Mortality Air Pollution Study (NMMAPS) for the period 1987 - 1994. At the first stage, we define a semi-parametric distributed lag Poisson regression model to estimate city-specific relative rates of CVDRESP ...

  1. Exposure to Multiple Languages Enhances Communication Skills in Infancy

    Science.gov (United States)

    Liberman, Zoe; Woodward, Amanda L.; Keysar, Boaz; Kinzler, Katherine D.

    2017-01-01

    Early exposure to multiple languages can enhance children's communication skills, even when children are effectively monolingual (Fan, Liberman, Keysar & Kinzler, 2015). Here we report evidence that the social benefits of multilingual exposure emerge in infancy. Sixteen-month-old infants participated in a communication task that required…

  2. Enhanced photocatalytic ozonation of organics by g-C{sub 3}N{sub 4} under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Gaozu, E-mail: liaogaozu@m.scnu.edu.cn; Zhu, Dongyun; Li, Laisheng, E-mail: llsh@scnu.edu.cn; Lan, Bingyan

    2014-09-15

    Highlights: • g-C{sub 3}N{sub 4} is employed as active catalyst in the photocatalytic ozonation system. • The more negative conduction band of g-C{sub 3}N{sub 4} benefits the transfer of electrons. • The synergistic effect between photocatalysis and ozonation is promoted by g-C{sub 3}N{sub 4}. • Enhanced degradation of oxalic acid and biphenol A is achieved via g-C{sub 3}N{sub 4}/Vis/O{sub 3}. - Abstract: Graphitic carbon nitride (g-C{sub 3}N{sub 4}) was employed as the active photocatalyst in the photocatalytic ozonation coupling system in the present study. g-C{sub 3}N{sub 4} was prepared by directly heating thiourea in air at 550 °C. XRD, FT-IR, UV–vis was used to characterize the structure and optical property. Oxalic acid and bisphenol A were selected as model substances for photocatalytic ozonation reactions to evaluate the catalytic ability of g-C{sub 3}N{sub 4} (g-C{sub 3}N{sub 4}/Vis/O{sub 3}). The results showed that the degradation ratio of oxalic acid with g-C{sub 3}N{sub 4}/Vis/O{sub 3} was 65.2% higher than the sum of ratio when it was individually decomposed by g-C{sub 3}N{sub 4}/Vis and O{sub 3}. The TOC removal of biphenol A with g-C{sub 3}N{sub 4}/Vis/O{sub 3} was 2.17 times as great as the sum of the ratio when using g-C{sub 3}N{sub 4}/Vis and O{sub 3}. This improvement was attributed to the enhanced synergistic effect between photocatalysis and ozonation by g-C{sub 3}N{sub 4}. Under visible light irradiation, the photo-generated electrons produced on g-C{sub 3}N{sub 4} facilitated the electrons transfer owing to the more negative conduction band potential (−1.3 V versus NHE). It meant that the photo-generated electrons could be trapped by ozone and reaction with it more easily. Subsequently, the yield of hydroxyl radicals was improved so as to enhance the organics degradation efficiency. This work indicated that metal-free g-C{sub 3}N{sub 4} could be an excellent catalyst for mineralization of organic compounds in waste control.

  3. Effect of Tin Electrode (Sn, Electrode Distance and Thin Layer Size of Zinc Phthalocyanine (ZnPc to Resistance Changes With Ozone Exposure

    Directory of Open Access Journals (Sweden)

    Agustina Mogi

    2018-01-01

    Full Text Available This study was aimed to determine the effect of tin electrode distances and the thickness of a thin layer of ZnPc (Zinc phtyalocyanine toward changes in resistance with ozone exposure. Tin deposition on the glass surface was conducted using spraying method. The reaction between ozone and ZnPc produces electrical properties that can be read through the resistance value of the multimeter. Based on this study, it was investigated that the smaller a distance between the electrode and the thicker deposition of ZnPc lead to the less resistance. This showed that a thin layer of the conductivity increases along with the longer exposure to ozone gas. The movement of electrons with the hole was free.

  4. Effects of Drought Stress and Ozone Exposure on Isoprene Emissions from Oak Seedlings in Texas

    Science.gov (United States)

    Madronich, M. B.; Harte, A.; Schade, G. W.

    2014-12-01

    Isoprene is the dominant hydrocarbon emitted by plants to the atmosphere with an approximate global emission of 550 Tg C yr-1. Isoprene emission studies have elucidated plants' isoprene production capacity, and the controlling factors of instantaneous emissions. However, it is not yet well understood how long-term climatic factors such as drought and increasing ozone concentrations affect isoprene emission rates. Drought reduces photosynthetic activity and is thus expected to reduce isoprene emission rate, since isoprene production relies on photosynthates. On the other hand, ozone is also known to negatively affect photosynthesis rates, but can instead increase isoprene emissions. These apparent inconsistencies and a lack of experimental data make it difficult to accurately parameterize isoprene emission responses to changing environmental conditions. The objective of this work is to reduce some of these uncertainties, using oak seedlings as a study system. Our project focuses on isoprene emission responses of oak trees to typical summer drought and high ozone conditions in Texas. We report on experiments conducted using a laboratory whole-plant chamber and leaf-level data obtained from greenhouse-grown seedlings. The chamber experiment studied the effects of ozone and drought on isoprene emissions from >3 year old oak seedlings under controlled conditions of photosynthetically active radiation (PAR), temperature, soil-moisture and the chamber's air composition. Stress in plants was induced by manipulating potted soil-moisture and ozone concentration in the chamber. The greenhouse study focused on understanding the effects of drought under Texas climatic conditions. For this study we used two year old seedlings of water oak (Quercus nigra) and post oak (Quercus stellata). Temperature, humidity and light in the greenhouse followed local conditions. Leaf-level conductance, photosynthesis measurements and isoprene sampling were carried out under controlled leaf

  5. Health Effects of Ozone Pollution

    Science.gov (United States)

    Inhaling ozone can cause coughing, shortness of breath, worse asthma or bronchitis symptoms, and irritation and damage to airways.You can reduce your exposure to ozone pollution by checking air quality where you live.

  6. Short-term respiratory effects of 0. 12 ppm ozone exposure in volunteers with chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Linn, W.S.; Fischer, D.A.; Medway, D.A.; Anzar, U.T.; Spier, C.E.; Valencia, L.M.; Venet, T.G.; Hackney, J.D.

    1982-06-01

    Twenty-five volunteers with chronic obstructive pulmonary disease of mild to moderately severe degree underwent 1-h exposures to 0.12 ppm ozone (O/sub 2/) in purified air with intermittent mild exercise. Their responses were assessed in terms of forced expiratory performance, ear oximetry, and reported symptoms. Control studied consisted of similar exposures to purified air alone. Control studies were separated from O/sub 2/ exposures by 1 month, and the order was randomized. All studies took place in a controlled-environment chamber, and were preceded by approximately 1 h of rest in a purified-air environment. No significant disturbances in forced expiratory performance or symptoms attributable to O/sub 2/ exposure were found. A slight but significant tendency to decreased arterial hemoglobin oxygen saturation (SaO/sub 2/) during exercise in O/sub 2/ was observed. The decrement in SaO/sub 2/ with O/sub 2/ relative to clean air (mean 1.3%) was near the limit of resolution of the ear oximeter test and was detected by signal averaging, thus its physiologic or clinical significance is uncertain.

  7. Physiological and biochemical stress responses in grassland species are influenced by both early-season ozone exposure and interspecific competition

    Energy Technology Data Exchange (ETDEWEB)

    Scebba, Francesca [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Canaccini, Francesca [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Castagna, Antonella [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Bender, Juergen [Institute of Agroecology, FAL, Bundesallee 50, 38116 Braunschweig (Germany); Weigel, Hans-Joachim [Institute of Agroecology, FAL, Bundesallee 50, 38116 Braunschweig (Germany); Ranieri, Annamaria [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy)]. E-mail: aranieri@agr.unipi.it

    2006-08-15

    The effects of two-year early season ozone exposure on physiological and biochemical stress response were investigated in model plant communities. Achillea millefolium and Veronica chamaedrys target plants were grown in monocultures and in mixed cultures with Poa pratensis (phytometer) and exposed in open-top chambers over two years for five weeks to charcoal-filtered (CF) air plus 25 nl l{sup -1} O{sub 3} (control) and non-filtered (NF) air plus 50 nl l{sup -1} O{sub 3}. Significant O{sub 3} effects were detected in different physiological and biochemical parameters, evidencing interspecific differences in metabolic stress responses and a strong influence of the competition factor. O{sub 3} induced strong oxidative effects in Achillea irrespective to the different growth modality. Veronica showed less O{sub 3}-induced effects in monoculture than when grown in competition with the phytometer. Poa exhibited a different behaviour against O{sub 3} depending on the species in competition, showing an overall higher sensitivity to O{sub 3} when in mixture with Achillea. - The competition between species modulates the ozone effect in a short-term.

  8. Physiological and biochemical stress responses in grassland species are influenced by both early-season ozone exposure and interspecific competition

    International Nuclear Information System (INIS)

    Scebba, Francesca; Canaccini, Francesca; Castagna, Antonella; Bender, Juergen; Weigel, Hans-Joachim; Ranieri, Annamaria

    2006-01-01

    The effects of two-year early season ozone exposure on physiological and biochemical stress response were investigated in model plant communities. Achillea millefolium and Veronica chamaedrys target plants were grown in monocultures and in mixed cultures with Poa pratensis (phytometer) and exposed in open-top chambers over two years for five weeks to charcoal-filtered (CF) air plus 25 nl l -1 O 3 (control) and non-filtered (NF) air plus 50 nl l -1 O 3 . Significant O 3 effects were detected in different physiological and biochemical parameters, evidencing interspecific differences in metabolic stress responses and a strong influence of the competition factor. O 3 induced strong oxidative effects in Achillea irrespective to the different growth modality. Veronica showed less O 3 -induced effects in monoculture than when grown in competition with the phytometer. Poa exhibited a different behaviour against O 3 depending on the species in competition, showing an overall higher sensitivity to O 3 when in mixture with Achillea. - The competition between species modulates the ozone effect in a short-term

  9. Effects of Acute Ozone Exposure and Methyl Jasmonate Treatment on White Pine Monoterpene and Sesquiterpene Emission Rates

    Science.gov (United States)

    Faiola, C. L.; Wagner, D.; Allwine, E.; Harley, P. C.; Vanreken, T. M.

    2010-12-01

    Biogenic volatile organic compounds (BVOCs) are produced by plants and include monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are one of the principal factors influencing the oxidative capacity of the atmosphere in forested regions, and impact both ozone concentration and secondary organic aerosol formation. Under unstressed conditions, the release of BVOCs to the atmosphere is primarily controlled by the vapor pressure of the relevant compounds within the plant tissue, which is in turn dependent on temperature as well as complex biochemical production processes. However, various natural and anthropogenic stressors can alter both the quantity and composition of the BVOCs emitted by plants. Many potential stressors are expected to become stronger as climate change effects escalate. The impacts of most stressors on BVOC emissions have not been well characterized, particularly in a field setting where changes in BVOC emissions could have influential feedbacks with climate. This study investigated the effects of two stressors on monoterpene and sesquiterpene emission rates at a field site in northern Michigan: acute ozone exposure and treatment with methyl jasmonate, an herbivory proxy. The study included six repetitions of the same experiment, each time using a new set of sub-canopy eastern white pine specimens. For each experiment, dynamic branch enclosures were simultaneously used on three specimens for sample collection: one ozone treatment tree, one methyl jasmonate treatment tree, and one control tree. Sampling lines were placed in each enclosure and VOCs were collected onto cartridges packed with Tenax GR adsorbent. Samples were collected several times per day for at least two days before treatment and for five days after treatment. Cartridges were analyzed via thermodesorption with an Agilent GC/MS/FID. This analysis allowed the identification and quantification of several monoterpene and sesquiterpene species in the samples

  10. Acute Ozone (O3) Exposure Accelerates Diet-Induced Pulmonary Injury and Metabolic Alterations in a Rat Model of Type II Diabetes

    Science.gov (United States)

    Abstract for Society of Toxicology, March 22-25, 2015, San Diego, CAAcute Ozone (O3) Exposure Accelerates Diet-Induced Pulmonary Injury and Metabolic Alterations in a Rat Model of Type II DiabetesS.J. Snow1,3, D. Miller2, V. Bass2, M. Schladweiler3, A. Ledbetter3, J. Richards3, C...

  11. Role of surfactant protein-A (SP-A) in lung injury in response to acute ozone exposure of SP-A deficient mice

    International Nuclear Information System (INIS)

    Haque, Rizwanul; Umstead, Todd M.; Ponnuru, Padmavathi; Guo Xiaoxuan; Hawgood, Samuel; Phelps, David S.; Floros, Joanna

    2007-01-01

    Millions are exposed to ozone levels above recommended limits, impairing lung function, causing epithelial damage and inflammation, and predisposing some individuals to pneumonia, asthma, and other lung conditions. Surfactant protein-A (SP-A) plays a role in host defense, the regulation of inflammation, and repair of tissue damage. We tested the hypothesis that the lungs of SP-A(-/-) (KO) mice are more susceptible to ozone-induced damage. We compared the effects of ozone on KO and wild type (WT) mice on the C57BL/6 genetic background by exposing them to 2 parts/million of ozone for 3 or 6 h and sacrificing them 0, 4, and 24 h later. Lungs were subject to bronchoalveolar lavage (BAL) or used to measure endpoints of oxidative stress and inflammation. Despite more total protein in BAL of KO mice after a 3 h ozone exposure, WT mice had increased oxidation of protein and had oxidized SP-A dimers. In KO mice there was epithelial damage as assessed by increased LDH activity and there was increased phospholipid content. In WT mice there were more BAL PMNs and elevated macrophage inflammatory protein (MIP)-2 and monocyte chemoattractant protein (MCP)-1. Changes in MIP-2 and MCP-1 were observed in both KO and WT, however mRNA levels differed. In KO mice MIP-2 mRNA levels changed little with ozone, but in WT levels they were significantly increased. In summary, several aspects of the inflammatory response differ between WT and KO mice. These in vivo findings appear to implicate SP-A in regulating inflammation and limiting epithelial damage in response to ozone exposure

  12. Efficiency enhancement of silicon nanowire solar cells by using UV/Ozone treatments and micro-grid electrodes

    Science.gov (United States)

    Chen, Junyi; Subramani, Thiyagu; Sun, Yonglie; Jevasuwan, Wipakorn; Fukata, Naoki

    2018-05-01

    Silicon nanowire solar cells were fabricated by metal catalyzed electroless etching (MCEE) followed by thermal chemical vapor deposition (CVD). In this study, we investigated two effects, a UV/ozone treatment and the use of a micro-grid electrodes, to enhance light absorption and reduce the optic losses in the solar cell device. The UV/ozone treatment successfully improved the conversion efficiency. The micro-grid electrodes were then applied in solar cell devices subjected to a back surface field (BSF) treatment and rapid thermal annealing (RTA). These effects improved the conversion efficiency from 9.4% to 10.9%. Moreover, to reduce surface recombination and improve the continuity of front electrodes, we optimized the etching time of the MCEE process, giving a high efficiency of 12.3%.

  13. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    Energy Technology Data Exchange (ETDEWEB)

    Pride, Kerry R., E-mail: hgp3@cdc.gov [Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA (United States); Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Peel, Jennifer L. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523 (United States); Robinson, Byron F. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 1600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Busacker, Ashley [Field Support Branch, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Grandpre, Joseph [Chronic Disease Epidemiologist, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Bisgard, Kristine M. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 600 Clifton Road, NE, E-92, Atlanta, GA 30333 (United States); Yip, Fuyuen Y. [Air Pollution and Respiratory Disease Branch, Centers for Disease Control and Prevention, 600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Murphy, Tracy D. [Wyoming Department of Health, 101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States)

    2015-02-15

    Objective: Short-term exposure to ground-level ozone has been linked to adverse respiratory and other health effects; previous studies typically have focused on summer ground-level ozone in urban areas. During 2008–2011, Sublette County, Wyoming (population: ~10,000 persons), experienced periods of elevated ground-level ozone concentrations during the winter. This study sought to evaluate the association of daily ground-level ozone concentrations and health clinic visits for respiratory disease in this rural county. Methods: Clinic visits for respiratory disease were ascertained from electronic billing records of the two clinics in Sublette County for January 1, 2008–December 31, 2011. A time-stratified case-crossover design, adjusted for temperature and humidity, was used to investigate associations between ground-level ozone concentrations measured at one station and clinic visits for a respiratory health concern by using an unconstrained distributed lag of 0–3 days and single-day lags of 0 day, 1 day, 2 days, and 3 days. Results: The data set included 12,742 case-days and 43,285 selected control-days. The mean ground-level ozone observed was 47±8 ppb. The unconstrained distributed lag of 0–3 days was consistent with a null association (adjusted odds ratio [aOR]: 1.001; 95% confidence interval [CI]: 0.990–1.012); results for lags 0, 2, and 3 days were consistent with the null. However, the results for lag 1 were indicative of a positive association; for every 10-ppb increase in the 8-h maximum average ground-level ozone, a 3.0% increase in respiratory clinic visits the following day was observed (aOR: 1.031; 95% CI: 0.994–1.069). Season modified the adverse respiratory effects: ground-level ozone was significantly associated with respiratory clinic visits during the winter months. The patterns of results from all sensitivity analyzes were consistent with the a priori model. Conclusions: The results demonstrate an association of increasing ground

  14. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    International Nuclear Information System (INIS)

    Pride, Kerry R.; Peel, Jennifer L.; Robinson, Byron F.; Busacker, Ashley; Grandpre, Joseph; Bisgard, Kristine M.; Yip, Fuyuen Y.; Murphy, Tracy D.

    2015-01-01

    Objective: Short-term exposure to ground-level ozone has been linked to adverse respiratory and other health effects; previous studies typically have focused on summer ground-level ozone in urban areas. During 2008–2011, Sublette County, Wyoming (population: ~10,000 persons), experienced periods of elevated ground-level ozone concentrations during the winter. This study sought to evaluate the association of daily ground-level ozone concentrations and health clinic visits for respiratory disease in this rural county. Methods: Clinic visits for respiratory disease were ascertained from electronic billing records of the two clinics in Sublette County for January 1, 2008–December 31, 2011. A time-stratified case-crossover design, adjusted for temperature and humidity, was used to investigate associations between ground-level ozone concentrations measured at one station and clinic visits for a respiratory health concern by using an unconstrained distributed lag of 0–3 days and single-day lags of 0 day, 1 day, 2 days, and 3 days. Results: The data set included 12,742 case-days and 43,285 selected control-days. The mean ground-level ozone observed was 47±8 ppb. The unconstrained distributed lag of 0–3 days was consistent with a null association (adjusted odds ratio [aOR]: 1.001; 95% confidence interval [CI]: 0.990–1.012); results for lags 0, 2, and 3 days were consistent with the null. However, the results for lag 1 were indicative of a positive association; for every 10-ppb increase in the 8-h maximum average ground-level ozone, a 3.0% increase in respiratory clinic visits the following day was observed (aOR: 1.031; 95% CI: 0.994–1.069). Season modified the adverse respiratory effects: ground-level ozone was significantly associated with respiratory clinic visits during the winter months. The patterns of results from all sensitivity analyzes were consistent with the a priori model. Conclusions: The results demonstrate an association of increasing ground

  15. Ozone exposure is associated with acute changes in inflammation, fibrinolysis, and endothelial cell function in coronary artery disease patients

    Science.gov (United States)

    Background: Air pollution is a major risk factor for cardiovascular disease, of which ozone is a major contributor. Several studies have found associations between ozone and cardiovascular morbidity, but the results have been inconclusive. We investigated associations between oz...

  16. Ozone exposure alters temporal fluctuations of 14C-labeled assimilate pools in leaves of Pinus taeda L

    International Nuclear Information System (INIS)

    Friend, A.L.; Tomlinson, P.T.

    1991-01-01

    The effects of O 3 on uptake and distribution of 14 C within current-year foliage of 3-year-old loblolly pine (Pinus taeda L.) seedlings were studied using open-top exposure chambers that delivered ozone at three concentrations: sub-ambient O 3 [charcoal-filtered air (CF)]; ambient O 3 (AMB); and twice-ambient O 3 (2X). Seedlings were exposed to O 3 from May to Oct. of 1987, 1988, and 1989. In July, Aug., and Sept. 1989, individual foliage fascicles were labeled with 14 CO 2 ; harvested at 0, 0.5, 4, 24, and 48h after labeling; and analyzed for 14 C in lipids and pigments, protein, starch, residue, sugars, organic acids, and amino acids. O 3 affected initial (0 h) incorporation of 14 C into different chemical fractions, and the relative distribution of 14 C among fractions at specific points in time. Starch dynamics were particularly responsive to and negatively affected by O 3 . In 2X treatments, only 39-46% of the initial (0 h) 14 C incorporated into starch remained after 48h, compared with a range of 56-90% remaining in CF treatments. The percentage of 14 C in the starch fraction after 48 h decreased by nearly three-fold in August from CF to 2X treatments [%total 14 C in starch: 31% (CF), 17% (AMB), and 11% (2X)]. The authors data indicated that foliar starch synthesis and/or retention was depressed by ozone exposure during late-season months, and supported the concept that O 3 decreases growth by depleting carbohydrate reserves. Other findings will be discussed

  17. Ozone exposure- and flux-based response relationships with photosynthesis of winter wheat under fully open air condition.

    Science.gov (United States)

    Feng, Zhaozhong; Calatayud, Vicent; Zhu, Jianguo; Kobayashi, Kazuhiko

    2018-04-01

    Five winter wheat cultivars were exposed to ambient (A-O 3 ) and elevated (E-O 3 , 1.5 ambient) O 3 in a fully open-air fumigation system in China. Ozone exposure- and flux based response relationships were established for seven physiological variables related to photosynthesis. The performance of the fitting of the regressions in terms of R 2 increased when second order regressions instead of first order ones were used, suggesting that effects of O 3 were more pronounced towards the last developmental stages of the wheat. The more robust indicators were those related with CO 2 assimilation, Rubisco activity and RuBP regeneration capacity (A sat , J max and Vc max ), and chlorophyll content (Chl). Flux-based metrics (POD y , Phytotoxic O 3 Dose over a threshold ynmolO 3 m -2 s -1 ) predicted slightly better the responses to O 3 than exposure metrics (AOTX, Accumulated O 3 exposure over an hourly Threshold of X ppb) for most of the variables. The best performance was observed for metrics POD 1 ( A sat , J max and Vc max ) and POD 3 (Chl). For this crop, the proposed response functions could be used for O 3 risk assessment based on physiological effects and also to include the influence of O 3 on yield or other variables in models with a photosynthetic component. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Short-term UV-B radiation and ozone exposure effects on aromatic secondary metabolite accumulation and shoot growth of flavonoid-deficient Arabidopsis mutants

    International Nuclear Information System (INIS)

    Ormrod, D.P.; Landry, L.G.; Conklin, P.L.

    1995-01-01

    The presence of UV-absorptive substances in the epidermal cells of leaves is thought to protect mesophyll tissues from the harmful effects of UV-B radiation. We examined the influence of short-term UV-B exposures on UV-absorptive (330 nm) sinapates and flavonols, and on shoot growth of the Arabidopsis wild type ecotype Landsberg erecta and two mutants. 114 deficient in chalcone synthase, and 115, deficient in chalcone/flavonone isomerase. Sequential ozone exposures were used to determine the effects of oxidative stress The levels of sinapates and flavonols on a leaf fresh weight basis increased substantially in the wild type and sinapates increased in the 114 mutant in vegetative vegetative/reproductive transitional and reproductive stage plants in response to short-term (48h) UV-B radiation. When UV-B was discontinued the levels generally decreased lo pre-exposure levels after 48 h in vegetative/reproductive but not in reproductive plants. Exposure to ozone before or alter UV-B treatment did not consistently affect the levels of these UV-absorptive compounds. Dry matter accumulation was less affected by UV-B at the vegetative and reproductive stages than at the vegetative/reproductive stage. At the vegetative/reproductive stage, shoot growth of all 3 genotypes was retarded by UV-B. Growth was not retarded by short-term ozone exposure alone but when exposure to ozone followed UV-B exposure, growth was reduced in all genotypes. Leaf cupping appeared on 115 plants exposed to UV-B

  19. Competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile Norway spruces and European beech

    International Nuclear Information System (INIS)

    Liu, X.; Rennenberg, H.; Kozovits, A. R.; Grams, T. E.; Blaschke, H.; Matyssek, R.

    2004-01-01

    Potential interactions of carbon dioxide and ozone on carbohydrate concentrations and contents were studied in Norway spruce and European beech saplings to test the hypotheses that (1) prolonged exposure to elevated carbon dioxide does not compensate for the limiting effects of ozone on the accumulation of sugars and starches, or biomass partitioning to the root; and (2) growth of mixed-species planting will repress plant responses to elevated ozone and carbon dioxide. Norway spruce and European beech saplings were acclimated for one year to ambient and elevated carbon dioxide, followed by exposure to factorial combinations of ambient and elevated ozone and carbon dioxide during the next two years. In spruce trees, sugar and starch content was greater in saplings exposed to elevated carbon dioxide; in beech, the response was the opposite. The overall conclusion was that the results did not support Hypothesis One, because the adverse effects were counteracted by elevated carbon dioxide. Regarding Hypothesis Two, it was found to be supportive for beech but not for spruce. In beech, the reduction of sugars and starch by elevated ozone and stimulation by elevated carbon dioxide were repressed by competitive interaction with spruce, whereas in spruce saplings elevated concentrations of carbon dioxide resulted in higher concentrations of sugar and starch, but only in leaves and coarse roots and only when grown in combination with beech. Elevated ozone in spruce saplings produced no significant effect on sugar or starch content either in intra- or interspecific competition. 57 refs., 1 tab., 5 figs

  20. Competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile Norway spruces and European beech

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.; Rennenberg, H. [University of Freiburg, Inst. of Forest Botany and Tree Physiology, Freiburg (Germany); Kozovits, A. R.; Grams, T. E.; Blaschke, H.; Matyssek, R. [Technische Universitat Munchen, Dept. of Ecology and Ecophysiology of Plants, Freising (Germany)

    2004-09-01

    Potential interactions of carbon dioxide and ozone on carbohydrate concentrations and contents were studied in Norway spruce and European beech saplings to test the hypotheses that (1) prolonged exposure to elevated carbon dioxide does not compensate for the limiting effects of ozone on the accumulation of sugars and starches, or biomass partitioning to the root; and (2) growth of mixed-species planting will repress plant responses to elevated ozone and carbon dioxide. Norway spruce and European beech saplings were acclimated for one year to ambient and elevated carbon dioxide, followed by exposure to factorial combinations of ambient and elevated ozone and carbon dioxide during the next two years. In spruce trees, sugar and starch content was greater in saplings exposed to elevated carbon dioxide; in beech, the response was the opposite. The overall conclusion was that the results did not support Hypothesis One, because the adverse effects were counteracted by elevated carbon dioxide. Regarding Hypothesis Two, it was found to be supportive for beech but not for spruce. In beech, the reduction of sugars and starch by elevated ozone and stimulation by elevated carbon dioxide were repressed by competitive interaction with spruce, whereas in spruce saplings elevated concentrations of carbon dioxide resulted in higher concentrations of sugar and starch, but only in leaves and coarse roots and only when grown in combination with beech. Elevated ozone in spruce saplings produced no significant effect on sugar or starch content either in intra- or interspecific competition. 57 refs., 1 tab., 5 figs.

  1. Neurobehavioral development of CD-1 mice after combined gestational and postnatal exposure to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Dell` Omo, G [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Fiore, M [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Petruzzi, S [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Alleva, E [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Bignami, G [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy)

    1995-09-01

    Outbred CD-1 mice were exposed continuously to ozone (O{sub 3}, 0.6 ppm) from 6 days prior to the formation of breeding pairs to the time of weaning of the offspring on postnatal day 22 (PND 22) or to PND 26. One half of the mice in each of eight O{sub 3} and eight control litters were subjected on PND 24 to a 20-min open-field test after IP treatment by either saline or scopolamine (2 mg/kg). The remaining mice (those exposed until PND 26) were subjected on PNDs 28-31 to a conditioned place preference (CPP) test, using a short schedule with a single IP injection on PND 29 of either d-amphetamine (3.3 mg/kg) or saline. Subsequently, the saline mice of the open-field experiment were used on PND 59 for an activity test in one of the CPP apparatus compartments after IP treatment by either d-amphetamine (same dose) or saline. In addition, the saline mice of the CPP experiment underwent a multitrial, step-through passive avoidance (PA) acquisition test on PND 59 or 60, followed 24 h later by a single-trial retention test. In the absence of effects on reproductive performance (proportion of successful pregnancies, litter size, offspring viability, and sex ratio), O{sub 3} offspring showed a long-lasting reduction in body weight without modification of sec differences. Ozone effects on neurobehavioral development were not large and quite selective, including: attenuation of the sex differences in several responses (rearing and sniffing in the open-field, activity in the final CPP test session); a change in response choices in the final CPP test, in the absence of a main effect on conditioning; a reduction of grooming in the activity test on PND 29; and impairment of PA acquisition limited to the initial period of training. (orig.)

  2. Neurobehavioral development of CD-1 mice after combined gestational and postnatal exposure to ozone.

    Science.gov (United States)

    Dell'Omo, G; Fiore, M; Petruzzi, S; Alleva, E; Bignami, G

    1995-01-01

    Outbred CD-1 mice were exposed continuously to ozone (O3, 0.6 ppm) from 6 days prior to the formation of breeding pairs to the time of weaning of the offspring on postnatal day 22 (PND 22) or to PND 26. One half of the mice in each of eight O3 and eight control litters were subjected on PND 24 to a 20-min open-field test after IP treatment by either saline or scopolamine (2 mg/kg). The remaining mice (those exposed until PND 26) were subjected on PNDs 28-31 to a conditioned place preference (CPP) test, using a short schedule with a single IP injection on PND 29 of either d-amphetamine (3.3 mg/kg) or saline. Subsequently, the saline mice of the open-field experiment were used on PND 59 for an activity test in one of the CPP apparatus compartments after IP treatment by either d-amphetamine (same dose) or saline. In addition, the saline mice of the CPP experiment underwent a multi-trial, step-through passive avoidance (PA) acquisition test on PND 59 or 60, followed 24 h later by a single-trial retention test. In the absence of effects on reproductive performance (proportion of successful pregnancies, litter size, offspring viability, and sex ratio), O3 offspring showed a long-lasting reduction in body weight without modification of sex differences. Ozone effects on neurobehavioral development were not large and quite selective, including: attenuation of the sex differences in several responses (rearing and sniffing in the open-field, activity in the final CPP test session); a change in response choices in the final CPP test, in the absence of a main effect on conditioning; a reduction of grooming in the activity test on PND 29; and impairment of PA acquisition limited to the initial period of training.

  3. Nitrogen soil emissions and belowground plant processes in Mediterranean annual pastures are altered by ozone exposure and N-inputs

    Science.gov (United States)

    Sánchez-Martín, L.; Bermejo-Bermejo, V.; García-Torres, L.; Alonso, R.; de la Cruz, A.; Calvete-Sogo, H.; Vallejo, A.

    2017-09-01

    Increasing tropospheric ozone (O3) and atmospheric nitrogen (N) deposition alter the structure and composition of pastures. These changes could affect N and C compounds in the soil that in turn can influence soil microbial activity and processes involved in the emission of N oxides, methane (CH4) and carbon dioxide (CO2), but these effects have been scarcely studied. Through an open top chamber (OTC) field experiment, the combined effects of both pollutants on soil gas emissions from an annual experimental Mediterranean community were assessed. Four O3 treatments and three different N input levels were considered. Fluxes of nitric (NO) and nitrous (N2O) oxide, CH4 and CO2 were analysed as well as soil mineral N and dissolved organic carbon. Belowground plant parameters like root biomass and root C and N content were also sampled. Ozone strongly increased soil N2O emissions, doubling the cumulative emission through the growing cycle in the highest O3 treatment, while N-inputs enhanced more slightly NO; CH4 and CO2 where not affected. Both N-gases had a clear seasonality, peaking at the start and at the end of the season when pasture physiological activity is minimal; thus, higher microorganism activity occurred when pasture had a low nutrient demand. The O3-induced peak of N2O under low N availability at the end of the growing season was counterbalanced by the high N inputs. These effects were related to the O3 x N significant interaction found for the root-N content in the grass and the enhanced senescence of the community. Results indicate the importance of the belowground processes, where competition between plants and microorganisms for the available soil N is a key factor, for understanding the ecosystem responses to O3 and N.

  4. Ozone carcinogenesis in vitro and its co-carcinogenesis with radiation

    International Nuclear Information System (INIS)

    Borek, C.

    1988-01-01

    Ozone (O/sub 3/), a reactive species of oxygen, is an important natural constituent of the atmosphere. Background levels of ozone in the lower atmosphere may range up to 0.1 ppm and are modified by geographic elevation, solar radiation and climatic conditions. Since some ozone effects are radiomimetic, its actions may be enhanced in the presence of ionizing radiation from background and/or manmade sources. While stratospheric ozone spares the earth from excess solar ultraviolet (UV) radiation, high levels of ozone in the environment are toxic and present a health hazard to man. Excess environmental exposure to ozone can result from a variety of sources. Ozone is a key component in oxidant smog and in the vicinity of high electric voltage equipment when in operation. Ozone is widely used as a disinfectant for air and water, in bleaches, waxes, textiles, oils. and inorganic synthesis. Enhanced levels of ozone are found in planes flying at high altitudes. Because of the toxic nature of ozone and its potential hazard to man, its levels in the environment are subject to government regulation. The current standard is set at an hourly average of 235 μg/m/sup 3/ (0.12 ppm) not to be exceeded more than once per year. Urban areas with high levels of photochemical smog (e.g. Southern California) may experience high ambient ozone levels which can reach 0.5 ppm

  5. Effects of Low Ozone Concentrations and Short Exposure Times on the Mortality of Immature Stages of the Indian Meal Moth, Plodia Interpunctella (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    Keivanloo Ensieh

    2014-07-01

    Full Text Available In Iran, the Indian meal moth, Plodia interpunctella (Hübner, is one of the most important pests of such stored products as date fruits and pistachio nuts. Ozone was applied as a gas at four concentrations (0, 2, 3, and 5 ppm for four different periods (30, 60, 90, and 120 min on the immature stages of P. interpunctella. The results indicated that by increasing the concentration and exposure time, the rate of mortality increased for all tested stages. This study showed that 12-day-old larvae were more susceptible than other stages when exposed to 5 ppm ozone for 120 min. The next in order of susceptibility were pupae, then 5-day-old larvae, and 17-dayold larvae had the highest sensitivity to ozonation. At the highest concentration of ozone, for the longest time, the least mortality rate was recorded for one-day-old eggs. According to the results, a reduction in the population density of P. interpunctella in laboratory experiments is promising. However, validation studies will be necessary to fully determine the potential of ozone as a replacement for the current post harvest chemical control of P. interpunctella on either pistachio nuts or date fruits.

  6. Enhanced ozone production in a pulsed dielectric barrier discharge plasma jet with addition of argon to a He-O2 flow gas

    Science.gov (United States)

    Sands, Brian; Ganguly, Biswa; Scofield, James

    2013-09-01

    Ozone production in a plasma jet DBD driven with a 20-ns risetime unipolar pulsed voltage can be significantly enhanced using helium as the primary flow gas with an O2 coflow. The overvolted discharge can be sustained with up to a 5% O2 coflow at pulse repetition frequency at 13 kV applied voltage. Ozone production scales with the pulse repetition frequency up to a ``turnover frequency'' that depends on the O2 concentration, total gas flow rate, and applied voltage. For example, peak ozone densities >1016 cm-3 were measured with 3% O2 admixture and discharge current and 777 nm O(5 P) emission, but decreased ozone production and is followed by a transition to a filamentary discharge mode. The addition of argon at concentrations >=5% reduces the channel conductivity and shifts the turnover frequency to higher frequencies. This results in increased ozone production for a given applied voltage and gas flow rate. Time-resolved Ar(1s5) and He(23S1) metastable densities were acquired along with discharge current and ozone density measurements to gain insight into the mechanisms of optimum ozone production.

  7. Enhanced pharmaceutical removal from water in a three step bio-ozone-bio process

    NARCIS (Netherlands)

    Wilt, de Arnoud; Gijn, van Koen; Verhoek, Tom; Vergnes, Amber; Hoek, Mirit; Rijnaarts, Huub; Langenhoff, Alette

    2018-01-01

    Individual treatment processes like biological treatment or ozonation have their limitations for the removal of pharmaceuticals from secondary clarified effluents with high organic matter concentrations (i.e. 17 mg TOC/L). These limitations can be overcome by combining these two processes for a

  8. Mechanism for enhanced degradation of clofibric acid in aqueous by catalytic ozonation over MnO{sub x}/SBA-15

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qiangqiang; Wang, Yu [School of Chemistry & Environment, South China Normal University, Guangzhou 510006 (China); Li, Laisheng, E-mail: llsh@scnu.edu.cn [School of Chemistry & Environment, South China Normal University, Guangzhou 510006 (China); Bing, Jishuai [Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang, Yingxin; Yan, Huihua [School of Chemistry & Environment, South China Normal University, Guangzhou 510006 (China)

    2015-04-09

    Highlights: • Clofibric acid (CA) is efficiently mineralized by O{sub 3}/MnO{sub x}/SBA-15. • Adsorption of CA and its intermediates on MnO{sub x}/SBA-15 is proved unimportant. • Initiation of hydroxyl radicals (·OH) is enhanced in O{sub 3}/MnO{sub x}/SBA-15. • Uniformly distributed MnO{sub x} accounts for the high activity of MnO{sub x}/SBA-15. • Degradation routes of CA in ozonation alone and catalytic ozonation are proposed. - Abstract: Comparative experiments were conducted to investigate the catalytic ability of MnO{sub x}/SBA-15 for the ozonation of clofibric acid (CA) and its reaction mechanism. Compared with ozonation alone, the degradation of CA was barely enhanced, while the removal of TOC was significantly improved by catalytic ozonation (O{sub 3}/MnO{sub x}/SBA-15). Adsorption of CA and its intermediates by MnO{sub x}/SBA-15 was proved unimportant in O{sub 3}/MnO{sub x}/SBA-15 due to the insignificant adsorption of CA and little TOC variation after ceasing ozone in stopped-flow experiment. The more remarkably inhibition effect of sodium bisulfite (NaHSO{sub 3}) on the removal of TOC in catalytic ozonation than in ozonation alone elucidated that MnO{sub x}/SBA-15 facilitated the generation of hydroxyl radicals (·OH), which was further verified by electron spin-resonance spectroscopy (ESR). Highly dispersed MnO{sub x} on SBA-15 were believed to be the main active component in MnO{sub x}/SBA-15. Some intermediates were indentified and different degradation routes of CA were proposed in both ozonation alone and catalytic ozonation. The amounts of small molecular carboxylic acids (i.e., formic acid (FA), acetic acid (AA) and oxalic acid (OA)) generated in catalytic ozonation were lower than in ozonation alone, resulting from the generation of more ·OH.

  9. Impacts of ozone-vegetation coupling and feedbacks on global air quality, ecosystems and food security

    Science.gov (United States)

    Tai, A. P. K.

    2016-12-01

    Surface ozone is an air pollutant of significant concerns due to its harmful effects on human health, vegetation and crop productivity. Chronic ozone exposure is shown to reduce photosynthesis and interfere with gas exchange in plants, thereby influencing surface energy balance and biogeochemical fluxes with important ramifications for climate and atmospheric composition, including possible feedbacks onto ozone itself that are not well understood. Ozone damage on crops has been well documented, but a mechanistic understanding is not well established. Here we present several results pertaining to the effects of ozone-vegetation coupling on air quality, ecosystems and agriculture. Using the Community Earth System Model (CESM), we find that inclusion of ozone damage on plants reduces the global land carbon sink by up to 5%, while simulated ozone is enhanced by up to 6 ppbv North America, Europe and East Asia. This strong positive feedback on ozone air quality via ozone-vegetation coupling arises mainly from reduced stomatal conductance, which induces two feedback pathways: 1) reduced dry deposition and ozone uptake; and 2) reduced evapotranspiration that enhances vegetation temperature and thus isoprene emission. Using the same ozone-vegetation scheme in a crop model within CESM, we further examine the impacts of historical ozone exposure on global crop production. We contrast our model results with a separate statistical analysis designed to characterize the spatial variability of crop-ozone-temperature relationships and account for the confounding effect of ozone-temperature covariation, using multidecadal global datasets of crop yields, agroclimatic variables and ozone exposures. We find that several crops (especially C4 crops such as maize) exhibit stronger sensitivities to ozone than found by field studies or in CESM simulations. We also find a strong anticorrelation between crop sensitivities and average ozone levels, reflecting biological adaptive ozone

  10. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    Science.gov (United States)

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  11. Ozone co-exposure modifies cardiac function responses to fine and ultrafine particulate matter in mice

    Science.gov (United States)

    There is growing evidence from epidemiological studies that show acute exposure to particulate matter (PM) increases the risk of cardiovascular morbidity and mortality. Although the data supporting these findings are increasingly more convincing, the immediate impact of PM inhala...

  12. Human Exposure to Dynamic Air Pollutants: Ozone in Airplanes and Ultrafine Particles in Homes

    Science.gov (United States)

    2010-01-01

    original source of my love of learning. All her grandchildren have had to tolerate, at least temporarily, being ignored while she was immersed in a book ...Indoor Air 17, 372-383. Klepeis NE, Nazaroff WW, 2006a. Modeling residential exposure to secondhand tobacco smoke. Atmospheric Environment 40, 4393...4407. Klepeis NE, Nazaroff WW, 2006b. Mitigating residential exposure to secondhand tobacco smoke. Atmospheric Environment 40, 4408-4422. 84

  13. Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

    Science.gov (United States)

    Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

    2009-11-01

    Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space.

  14. Affect labeling enhances exposure effectiveness for public speaking anxiety.

    Science.gov (United States)

    Niles, Andrea N; Craske, Michelle G; Lieberman, Matthew D; Hur, Christopher

    2015-05-01

    Exposure is an effective treatment for anxiety but many patients do not respond fully. Affect labeling (labeling emotional experience) attenuates emotional responding. The current project examined whether affect labeling enhances exposure effectiveness in participants with public speaking anxiety. Participants were randomized to exposure with or without affect labeling. Physiological arousal and self-reported fear were assessed before and after exposure and compared between groups. Consistent with hypotheses, participants assigned to Affect Labeling, especially those who used more labels during exposure, showed greater reduction in physiological activation than Control participants. No effect was found for self-report measures. Also, greater emotion regulation deficits at baseline predicted more benefit in physiological arousal from exposure combined with affect labeling than exposure alone. The current research provides evidence that behavioral strategies that target prefrontal-amygdala circuitry can improve treatment effectiveness for anxiety and these effects are particularly pronounced for patients with the greatest deficits in emotion regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Baseline gene expression in conjunction with GSTM1 status predicts ozone exposure response

    Science.gov (United States)

    Air pollution exposure causes increased cardiopulmonary morbidity and mortality and has been linked to the deaths of 7 million people every year by the World Health Organization. Approximately 40% of the population lack expression of the antioxidant enzyme glutathione S-transfer...

  16. Ozone: The secret greenhouse gas

    International Nuclear Information System (INIS)

    Berntsen, Terje; Tjernshaugen, Andreas

    2001-01-01

    The atmospheric ozone not only protects against harmful ultraviolet radiation; it also contributes to the greenhouse effect. Ozone is one of the jokers to make it difficult to calculate the climatic effect of anthropogenic emissions. The greenhouse effect and the ozone layer should not be confused. The greenhouse effect creates problems when it becomes enhanced, so that the earth becomes warmer. The problem with the ozone layer, on the contrary, is that it becomes thinner and so more of the harmful ultraviolet radiation gets through to the earth. However, ozone is also a greenhouse gas and so the greenhouse effect and the ozone layer are connected

  17. Effect of 3 years' free-air exposure to elevated ozone on mature Norway spruce (Picea abies (L.) Karst.) needle epicuticular wax physicochemical characteristics

    International Nuclear Information System (INIS)

    Percy, Kevin E.; Manninen, Sirkku; Haeberle, Karl-Heinz; Heerdt, C.; Werner, H.; Henderson, Gary W.; Matyssek, Rainer

    2009-01-01

    We examined the effect of ozone (O 3 ) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2x ambient O 3 ranged from 64.5 to 74.2 μl O 3 l -1 h AOT40, and 117.1 to 123.2 nl O 3 l -1 4th highest daily maximum 8-h average O 3 concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2x O 3 . Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O 3 treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2x O 3 . Exposure to 2x O 3 increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O 3 on wax biosynthesis. These results demonstrate O 3 -induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees. - Free-air ozone exposure induced changes in needle wax characteristics of mature Picea abies.

  18. Effect of 3 years' free-air exposure to elevated ozone on mature Norway spruce (Picea abies (L.) Karst.) needle epicuticular wax physicochemical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Percy, Kevin E., E-mail: kpercy@nbnet.nb.c [Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, 1350 Regent Street, Fredericton, NB, E3B 5P7 (Canada); Manninen, Sirkku [Department of Biological and Environmental Sciences, P.O. Box 56, University of Helsinki, 00014 Helsinki (Finland); Department of Biology, P.O. Box 3000, University of Oulu, 90014 Oulu (Finland); Haeberle, Karl-Heinz [Ecophysiology of Plants, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Heerdt, C.; Werner, H. [Ecoclimatology, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Henderson, Gary W. [Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, 1350 Regent Street, Fredericton, NB, E3B 5P7 (Canada); Matyssek, Rainer [Ecophysiology of Plants, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

    2009-05-15

    We examined the effect of ozone (O{sub 3}) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2x ambient O{sub 3} ranged from 64.5 to 74.2 mul O{sub 3} l{sup -1} h AOT40, and 117.1 to 123.2 nl O{sub 3} l{sup -1} 4th highest daily maximum 8-h average O{sub 3} concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2x O{sub 3}. Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O{sub 3} treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2x O{sub 3}. Exposure to 2x O{sub 3} increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O{sub 3} on wax biosynthesis. These results demonstrate O{sub 3}-induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees. - Free-air ozone exposure induced changes in needle wax characteristics of mature Picea abies.

  19. Physiological and biochemical stress responses in grassland species are influenced by both early-season ozone exposure and interspecific competition.

    Science.gov (United States)

    Scebba, Francesca; Canaccini, Francesca; Castagna, Antonella; Bender, Jürgen; Weigel, Hans-Joachim; Ranieri, Annamaria

    2006-08-01

    The effects of two-year early season ozone exposure on physiological and biochemical stress response were investigated in model plant communities. Achillea millefolium and Veronica chamaedrys target plants were grown in monocultures and in mixed cultures with Poa pratensis (phytometer) and exposed in open-top chambers over two years for five weeks to charcoal-filtered (CF) air plus 25 nl l(-1) O3 (control) and non-filtered (NF) air plus 50 nl l(-1) O3. Significant O3 effects were detected in different physiological and biochemical parameters, evidencing interspecific differences in metabolic stress responses and a strong influence of the competition factor. O3 induced strong oxidative effects in Achillea irrespective to the different growth modality. Veronica showed less O3-induced effects in monoculture than when grown in competition with the phytometer. Poa exhibited a different behaviour against O3 depending on the species in competition, showing an overall higher sensitivity to O3 when in mixture with Achillea.

  20. Enhanced charge transport and photovoltaic performance of PBDTTT-C-T/PC70BM solar cells via UV-ozone treatment.

    Science.gov (United States)

    Adhikary, Prajwal; Venkatesan, Swaminathan; Adhikari, Nirmal; Maharjan, Purna P; Adebanjo, Olusegun; Chen, Jihua; Qiao, Qiquan

    2013-10-21

    In this work, the electron transport layer of PBDTTT-C-T/PC70BM polymer solar cells were subjected to UV-ozone treatment, leading to improved cell performances from 6.46% to 8.34%. The solar cell efficiency reached a maximum of 8.34% after an optimal 5 minute UV-ozone treatment, and then decreased if treated for a longer time. To the best of our knowledge, the mechanism behind the effects of UV-ozone treatment on the improvement of charge transport and cell performance is not fully understood. We have developed a fundamental understanding of the UV-ozone treatment mechanism, which explains both the enhancements in charge transport and photovoltaic performance at an optimal treatment time, and also the phenomenon whereby further treatment time leads to a drop in cell efficiency. Transient photocurrent measurements indicated that the cell charge transport times were 1370 ns, 770 ns, 832 ns, 867 ns, and 1150 ns for the 0 min, 5 min, 10 min, 15 min, and 20 min UV-ozone treatment times, respectively. Therefore the 5 min UV-ozone treatment time led to the shortest transport time and the most efficient charge transport in the cells. The 5 min UV-ozone treated sample exhibited the highest peak intensity (E2) in the Raman spectra of the treated films, at about 437 cm(-1), indicating that it possessed the best wurtzite phase crystallinity of the ZnO films. Further increasing the UV-ozone treatment time from 5 to 20 min induced the formation of p-type defects (e.g. interstitial oxygen atoms), pushing the ZnO Fermi-level further away from the vacuum level, and decreasing the wurtzite crystallinity.

  1. Solar photo-ozonation: A novel treatment method for the degradation of water pollutants

    International Nuclear Information System (INIS)

    Chávez, Ana M.; Rey, Ana; Beltrán, Fernando J.; Álvarez, Pedro M.

    2016-01-01

    Highlights: • Aqueous ozone decomposition is accelerated by solar radiation. • Hydrogen peroxide is identifies as a main intermediate of decomposition of aqueous ozone under solar irradiation. • Solar photo-ozonation leads to higher Rct ratios than single ozonation. • Solar photo-ozonation is a promising AOP for the degradation of water pollutants. - Abstract: The decomposition of aqueous ozone by UV–vis radiation has been investigated with focus on the impact of ozone photolysis on the degradation of water pollutants during solar ozonation processes. The apparent first-order rate constants of the decomposition of ozone (k_o_b_s) have been determined at various pHs in the 4–9 range using radiation of different wavelengths in the UV–vis range. It was found that UVA–visible radiation (λ > 320 nm) highly enhanced ozone decomposition, especially at pH 4, for which k_o_b_s was three-folded with respect to the process in the absence of radiation. Hydrogen peroxide was identified as a main intermediate of ozone photo-decomposition at pH 4. Experiments of degradation of oxalic acid by ozone showed that solar irradiation brings about an increase in the hydroxyl radical to ozone exposures ratio (R_c_t). Finally, photo-ozonation (λ > 300 nm) was shown advantageous over single ozonation in the mineralization of a selection of emerging contaminants (metoprolol, ibuprofen, N,N-diethyl-meta-toluamide and clofibric acid) in both ultrapure water and a synthetic secondary effluent. Thus, TOC removal in 2-h treatments increased from 10 to 25% in the absence of radiation to about 50% in the presence of radiation.

  2. Solar photo-ozonation: A novel treatment method for the degradation of water pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Chávez, Ana M.; Rey, Ana; Beltrán, Fernando J.; Álvarez, Pedro M., E-mail: pmalvare@unex.es

    2016-11-05

    Highlights: • Aqueous ozone decomposition is accelerated by solar radiation. • Hydrogen peroxide is identifies as a main intermediate of decomposition of aqueous ozone under solar irradiation. • Solar photo-ozonation leads to higher Rct ratios than single ozonation. • Solar photo-ozonation is a promising AOP for the degradation of water pollutants. - Abstract: The decomposition of aqueous ozone by UV–vis radiation has been investigated with focus on the impact of ozone photolysis on the degradation of water pollutants during solar ozonation processes. The apparent first-order rate constants of the decomposition of ozone (k{sub obs}) have been determined at various pHs in the 4–9 range using radiation of different wavelengths in the UV–vis range. It was found that UVA–visible radiation (λ > 320 nm) highly enhanced ozone decomposition, especially at pH 4, for which k{sub obs} was three-folded with respect to the process in the absence of radiation. Hydrogen peroxide was identified as a main intermediate of ozone photo-decomposition at pH 4. Experiments of degradation of oxalic acid by ozone showed that solar irradiation brings about an increase in the hydroxyl radical to ozone exposures ratio (R{sub ct}). Finally, photo-ozonation (λ > 300 nm) was shown advantageous over single ozonation in the mineralization of a selection of emerging contaminants (metoprolol, ibuprofen, N,N-diethyl-meta-toluamide and clofibric acid) in both ultrapure water and a synthetic secondary effluent. Thus, TOC removal in 2-h treatments increased from 10 to 25% in the absence of radiation to about 50% in the presence of radiation.

  3. Ozone Treatment of Alveolar Bone in the Cape Chacma Baboon Does Not Enhance Healing Following Trauma

    OpenAIRE

    Kotze, Marthinus; Bütow, Kürt-W; Olorunju, Steve A.; Kotze, Harry F.

    2013-01-01

    In the international literature, the role of Ozone (O3) in the advancement in alveolar bone healing in the absence of bone pathology was not tested before. The purpose of this study was to evaluate alveolar bone regeneration after a bone defect was created and treated with a single topical administration of O3. Alveolar bone defects were created on five healthy chacma baboons. One side of the maxilla and mandible was topically treated with a single treatment of an O3/O2 mixture (3,5–4 % O3), ...

  4. Ozonation of Indigo Carmine Enhanced by Fe/Pimenta dioica L. Merrill Particles

    Directory of Open Access Journals (Sweden)

    Teresa Torres-Blancas

    2015-01-01

    Full Text Available Green synthesis of metallic particles has become an economic way to improve and protect the environment by decreasing the use of toxic chemicals and eliminating dyes. The synthesis of metal particles is gaining more importance due to its simplicity, rapid rate of synthesis of particles, and environmentally friendly. The present work aims to report a novel and environmentally friendly method for the synthesis of iron particles using deoiled Pimenta dioica L. Merrill husk as support. The indigo carmine removal efficiency by ozonation and catalyzed ozonation is also presented. Synthesized materials were characterized by N2 physisorption and scanning electron microscopy (SEM/EDS. By UV-Vis spectrophotometry the removal efficiency of indigo carmine was found to be nearly 100% after only 20 minutes of treatment under pH 3 and with a catalyst loading of 1000 mgL−1. Analytical techniques such as determination of the total organic carbon content (TOC and chemical oxygen demand (COD showed that iron particles supported on deoiled Pimenta dioica L. Merrill husk can be efficiently employed to degrade indigo carmine and achieved a partial mineralization (conversion to CO2 and H2O of the molecule. From the results can be inferred that the prepared biocomposite increases the hydroxyl radicals generation.

  5. Maternal exposure to ozone and PM{sub 2.5} and the prevalence of orofacial clefts in four U.S. states

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ying, E-mail: yzhou2@cdc.gov [Environmental Health Tracking Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Gilboa, Suzanne M. [Birth Defects Branch, Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA (United States); Herdt, Michele L. [New York State Department of Health, Center for Environmental Health, Albany, NY (United States); State University of New York at Albany, Department of Epidemiology and Biostatistics, Rensselaer, NY (United States); Lupo, Philip J. [Baylor College of Medicine, Department of Pediatrics, Section of Hematology-Oncology, Houston, TX (United States); Flanders, W. Dana [Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA (United States); Liu, Yang [Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA (United States); Shin, Mikyong [Environmental Health Tracking Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Canfield, Mark A. [Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, TX (United States); Kirby, Russell S. [Department of Community and Family Health, College of Public Health, University of South Florida, Tampa, FL (United States)

    2017-02-15

    Background: While there is some evidence that maternal exposure to ambient air pollution is associated with orofacial clefts in offspring, the epidemiologic studies have been largely equivocal. We evaluated whether maternal exposure to elevated county-level ambient fine particulate matter with aerodynamic diameter ≤2.5 µm (PM{sub 2.5}) and ozone during early gestation was associated with a higher prevalence of orofacial clefts. Methods: Birth data consisting of 4.7 million births from 2001 to 2007 were obtained from National Birth Defects Prevention Network for four states — Arizona, Florida, New York (excluding New York City), and Texas. The air pollution exposure assessment for gestational weeks 5–10 was based on county-level average concentrations of PM{sub 2.5} and ozone data generated using a Bayesian fusion model available through CDC's Environmental Public Health Tracking Network. Two outcomes were analyzed separately: cleft lip with or without cleft palate, cleft palate alone. In logistic regression analyses, we adjusted for factors that were suspected confounders or modifiers of the association between the prevalence of orofacial clefts and air pollution, i.e., infant sex, race-ethnicity, maternal education, smoking status during pregnancy, whether this was mother's first baby, maternal age. Results: Each 10 µg/m{sup 3} increase in PM{sub 2.5} concentration was significantly associated with cleft palate alone (OR =1.43, 95% CI: 1.11–1.86). There was no significant association between PM{sub 2.5} concentration and cleft lip with or without cleft palate. No associations were observed between ozone exposure and the two outcomes of orofacial clefts. Conclusions: Our study suggests that PM{sub 2.5} significantly increased the risk of cleft palate alone, but did not change the incidence of cleft lip with or without palate. Ozone levels did not correlate with incidence of orofacial clefts. - Highlights: • This is a large study with about 4

  6. Maternal exposure to ozone and PM2.5 and the prevalence of orofacial clefts in four U.S. states

    International Nuclear Information System (INIS)

    Zhou, Ying; Gilboa, Suzanne M.; Herdt, Michele L.; Lupo, Philip J.; Flanders, W. Dana; Liu, Yang; Shin, Mikyong; Canfield, Mark A.; Kirby, Russell S.

    2017-01-01

    Background: While there is some evidence that maternal exposure to ambient air pollution is associated with orofacial clefts in offspring, the epidemiologic studies have been largely equivocal. We evaluated whether maternal exposure to elevated county-level ambient fine particulate matter with aerodynamic diameter ≤2.5 µm (PM 2.5 ) and ozone during early gestation was associated with a higher prevalence of orofacial clefts. Methods: Birth data consisting of 4.7 million births from 2001 to 2007 were obtained from National Birth Defects Prevention Network for four states — Arizona, Florida, New York (excluding New York City), and Texas. The air pollution exposure assessment for gestational weeks 5–10 was based on county-level average concentrations of PM 2.5 and ozone data generated using a Bayesian fusion model available through CDC's Environmental Public Health Tracking Network. Two outcomes were analyzed separately: cleft lip with or without cleft palate, cleft palate alone. In logistic regression analyses, we adjusted for factors that were suspected confounders or modifiers of the association between the prevalence of orofacial clefts and air pollution, i.e., infant sex, race-ethnicity, maternal education, smoking status during pregnancy, whether this was mother's first baby, maternal age. Results: Each 10 µg/m 3 increase in PM 2.5 concentration was significantly associated with cleft palate alone (OR =1.43, 95% CI: 1.11–1.86). There was no significant association between PM 2.5 concentration and cleft lip with or without cleft palate. No associations were observed between ozone exposure and the two outcomes of orofacial clefts. Conclusions: Our study suggests that PM 2.5 significantly increased the risk of cleft palate alone, but did not change the incidence of cleft lip with or without palate. Ozone levels did not correlate with incidence of orofacial clefts. - Highlights: • This is a large study with about 4.7 million births and 7000

  7. Comparison of spatiotemporal prediction models of daily exposure of individuals to ambient nitrogen dioxide and ozone in Montreal, Canada.

    Science.gov (United States)

    Buteau, Stephane; Hatzopoulou, Marianne; Crouse, Dan L; Smargiassi, Audrey; Burnett, Richard T; Logan, Travis; Cavellin, Laure Deville; Goldberg, Mark S

    2017-07-01

    In previous studies investigating the short-term health effects of ambient air pollution the exposure metric that is often used is the daily average across monitors, thus assuming that all individuals have the same daily exposure. Studies that incorporate space-time exposures of individuals are essential to further our understanding of the short-term health effects of ambient air pollution. As part of a longitudinal cohort study of the acute effects of air pollution that incorporated subject-specific information and medical histories of subjects throughout the follow-up, the purpose of this study was to develop and compare different prediction models using data from fixed-site monitors and other monitoring campaigns to estimate daily, spatially-resolved concentrations of ozone (O 3 ) and nitrogen dioxide (NO 2 ) of participants' residences in Montreal, 1991-2002. We used the following methods to predict spatially-resolved daily concentrations of O 3 and NO 2 for each geographic region in Montreal (defined by three-character postal code areas): (1) assigning concentrations from the nearest monitor; (2) spatial interpolation using inverse-distance weighting; (3) back-extrapolation from a land-use regression model from a dense monitoring survey, and; (4) a combination of a land-use and Bayesian maximum entropy model. We used a variety of indices of agreement to compare estimates of exposure assigned from the different methods, notably scatterplots of pairwise predictions, distribution of differences and computation of the absolute agreement intraclass correlation (ICC). For each pairwise prediction, we also produced maps of the ICCs by these regions indicating the spatial variability in the degree of agreement. We found some substantial differences in agreement across pairs of methods in daily mean predicted concentrations of O 3 and NO 2 . On a given day and postal code area the difference in the concentration assigned could be as high as 131ppb for O 3 and 108ppb

  8. Enhanced Ozone Production at Low Temperatures due to Ethanol (E85)

    Science.gov (United States)

    Ginnebaugh, D. L.; Livingstone, P. L.; Jacobson, M. Z.

    2009-12-01

    The increased use of ethanol in transportation fuels warrants an investigation of its consequences. An important component of such an investigation is the temperature-dependence of ethanol and gasoline exhaust chemistry. We use the near-explicit Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate explicit chemistry to examine such effects. The MCM has over 13,500 organic reactions and 4,600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. Although for this study we use a box model, we determined that the speed of the MCM with the SMVGEAR solver will allow the MCM to be modeled in 3-dimensions. We also verified the accuracy of the model with comparisons to smog chamber data. We use species-resolved tailpipe emissions data for E85 (15% gasoline, 85% ethanol fuel blend) and gasoline vehicles to compare the impact of each on ozone and carcinogenic organic gases as a function of ambient temperature and background concentrations, using Los Angeles in 2020 as a base case. We use two different emissions sets - one is a compilation of data taken at near 24 C and the other from data taken at -7 C - to determine how atmospheric chemistry and emissions are affected by temperature. We include diurnal effects by examining 2 day and 5 day scenarios. We find that for both emission data sets, the average ozone concentrations through the range of temperatures tested are higher with E85 than with gasoline by 8 parts per billion volume (ppbv) at higher temperatures to 55 ppbv at low temperatures and low sunlight (winter conditions) for an area with a high nitrogen oxides (NOx) to non-methane organic gases (NMOG) ratio. The results suggest that E85's effect on health through ozone formation becomes increasingly more significant relative to gasoline as temperatures decreased due to the

  9. Effects of maternal high-fat diet and sedentary lifestyle on susceptibility of adult offspring to ozone exposure in rats.

    Science.gov (United States)

    Gordon, C J; Phillips, P M; Johnstone, A F M; Schmid, J; Schladweiler, M C; Ledbetter, A; Snow, S J; Kodavanti, U P

    2017-05-01

    Epidemiological and experimental data suggest that obesity exacerbates the health effects of air pollutants such as ozone (O 3 ). Maternal inactivity and calorically rich diets lead to offspring that show signs of obesity. Exacerbated O 3 susceptibility of offspring could thus be manifested by maternal obesity. Thirty-day-old female Long-Evans rats were fed a control (CD) or high-fat (HF) (60% calories) diet for 6 wks and then bred. GD1 rats were then housed with a running wheel (RW) or without a wheel (SED) until parturition, creating four groups of offspring: CD-SED, CD-RW, HF-SED and HF-RW. HF diet was terminated at PND 35 and all offspring were placed on CD. Body weight and %fat of dams were greatest in order; HF-SED > HF-RW > CD-SED > CD-RW. Adult offspring were exposed to O 3 for two consecutive days (0.8 ppm, 4 h/day). Glucose tolerance tests (GTT), ventilatory parameters (plethysmography), and bronchoalveolar fluid (BALF) cell counts and protein biomarkers were performed to assess response to O 3 . Exercise and diet altered body weight and %fat of young offspring. GTT, ventilation and BALF cell counts were exacerbated by O 3 with responses markedly exacerbated in males. HF diet and O 3 led to significant exacerbation of several BALF parameters: total cell count, neutrophils and lymphocytes were increased in male HF-SED versus CD-SED. Males were hyperglycemic after O 3 exposure and exhibited exacerbated GTT responses. Ventilatory dysfunction was also exacerbated in males. Maternal exercise had minimal effects on O 3 response. The results of this exploratory study suggest a link between maternal obesity and susceptibility to O 3 in their adult offspring in a sex-specific manner.

  10. Conversion of polycyclic aromatic hydrocarbons on diesel particulate matter upon exposure to ppm levels of ozone

    Science.gov (United States)

    Van Vaeck, L.; Van Cauwenberghe, K.

    Diesel exhaust particlulate matter samples were collected from a dilution tunnel using a Hi-Vol cascade impactor. The fraction of the aerosol with aerodynamic diameter below 0.5 μm, retained on the glass fiber back-up filter, was exposed to a flow of ozonised particle free air for periods of 0.5-4 h (1.5 ppm of O 3, flow rate about 40 m 3 h -1). Both exposed and non-exposed reference niters were Soxhlet-extracted with benzene and methanol, and the polycyclic aromatic hydrocarbon fraction (PAH) was isolated by a liquid-liquid partition procedure described in the literature, using cyclohexane and dimethylformamid-water as solvents, modified for quantitative recovery of PAH. The conversion yields of PAH upon exposure to O 3 were determined by single ion monitoring mass spectrometry using a fused silica capillary column for their separation. Significant conversion was observed for PAH from molecular weight 226 to 276. Approximate half lives are of the order of 0.5-1 h for most PAH measured. This high reactivity of PAH on a carbonaceous matrix is probably related to the large specific surface of soot particles as well as to their high adsorptive capacity for gaseous compounds. Lower molecular weight PAH up to chrysene also undergo important physical losses by volatilisation and the extent to which chemical transformations occurred could not be determined accurately. Different reactivities are observed for several isomeric pairs of PAH: benzo(a)pyrene is much faster converted than benzo(e)pyrene, benz(a)anthracene reacts faster than chrysene. The benzo-fluoranthenes are most resistant toward O 3 attack. The implications of these results with respect to atmospheric degradation of PAH, as well as to the occurrence of artefactual conversion upon Hi-Vol sampling are discussed.

  11. Enhanced natural radiation exposure enhanced by human activity: the largest contributor to the Chinese population dose

    International Nuclear Information System (INIS)

    Pan Ziqiang; Liu Yanyang

    2011-01-01

    For the radiation exposure caused by human activities, the enhanced natural radiation exposure is the largest contributor to Chinese population dose. This problem has attracted social attention in recent years. Efforts have been made in several fields, such as radon indoors and in workplace, environmental problems associated with NORMs, occupational radiation hazards of non-uranium mine, and radiation dose evaluation for energy chain, but there are still many problems to be solved. In order to protect the health of workers and the public, while ensuring industrial production and economic development, it is also necessary to continue to strengthen research in all aspects above mentioned, and gradually promote the control of natural radiation exposure enhanced by human activities. (authors)

  12. Perinatal alcohol exposure enhances nocistatin levels in adulthood.

    Science.gov (United States)

    Tekes, Kornélia; Hantos, Mónika; Gyenge, Melinda; Csaba, Gyorgy

    2007-06-01

    In earlier experiments perinatal hormonal imprinting by alcohol decreased the hormone content of immune cells for life. In the present study, both a single day (15% on the third postnatal day) and a long-term treatment schedule of alcohol exposure (3% for 21 days) of dams during lactation significantly (P < 0.01) enhanced endogenous levels of nocistatin in the blood plasma as well as in the cerebrospinal fluid of the offspring, measured in 3-month-old rats. Our data suggest that alcohol consumption during lactation can cause a life-long influence on nocistatin levels in the offspring and most likely modify nocistatin-related functions such as pain tolerance.

  13. Ozone exposure, vitamin C intake, and genetic susceptibility of asthmatic children in Mexico City: a cohort study

    Directory of Open Access Journals (Sweden)

    Moreno-Macías Hortensia

    2013-02-01

    Full Text Available Abstract Background We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF25-75 in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695, and NQO1 (rs1800566. Methods 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches. Results The change in FEF25-75 per interquartile range (60 ppb of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was −91.2 ml/s (p = 0.06. Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF25-75 of 97.2 ml/s per 60 ppb of ozone (p = 0.03. In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF25-75 did not differ by vitamin C intake. Conclusions Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

  14. What Is the Best Strategy for Enhancing the Effects of Topically Applied Ozonated Oils in Cutaneous Infections?

    Directory of Open Access Journals (Sweden)

    I. Zanardi

    2013-01-01

    Full Text Available Owing to diabetes, atherosclerosis, and ageing, there are several million patients undergoing skin lesions degenerated into infected ulcers with very little tendency to heal and implying a huge socioeconomical cost. Previous medical experience has shown that the daily application of ozonated oil eliminates the infection and promotes a rapid healing. The purpose of the study is the optimization of the antimicrobial effect of ozonated oils by testing in vitro four bacterial species and one yeast without or in the presence of different amounts of human serum. The results obtained suggest that a gentle and continuous removal of debris and exudate is an essential condition for the potent bactericidal effect of ozonated oils. In fact, even small amounts of human serum inactivate ozone derivatives and protect bacteria. The application of ozonated oil preparations is very promising in a variety of skin and mucosal infections. Moreover, ozonated oils are far less expensive than antibiotic preparations.

  15. Ozone exposure, defoliation of beech (Fagus sylvatica L.) and visible foliar symptoms on native plants in selected plots of South-Western Europe

    International Nuclear Information System (INIS)

    Ferretti, Marco; Calderisi, Marco; Bussotti, Filippo

    2007-01-01

    The relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in South-Western Europe in the years 2000-2002. Relationships between defoliation of beech and O 3 (seasonal mean, 2-week maximum, AOT40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). Different multiple regression techniques were used. The four models generated (R 2 = 0.71-0.85, explained variance in cross-validation 61-78%) identified several significant predictors of defoliation, with AOT40 (p = 0.008) and foliar content of phosphorous (p = 0.0002-0.0004) being common to all models. The autocorrelation model (R 2 = 0.55; p 35,000 ppbh). O 3 -like visible foliar symptoms were recorded on 65 species at 47% of the common monitoring sites in 2001 and 38% in 2002. No relationship was found between O 3 exposure, frequency of symptomatic sites and frequency of species with symptoms (R 2 = 0.11; p > 0.05). A number of questions related to the ecological and methodological basis of the survey were identified. Inherent sampling and non-sampling errors and multicollinearity of the data suggest great caution when examining results obtained from mensurational, correlative studies. - Ozone AOT40 was identified as a significant predictor of defoliation of beech, but a limited relationship was found between ozone exposure and visible symptoms on native vegetation

  16. Global environment and radiation exposure

    International Nuclear Information System (INIS)

    Okamoto, Kazuto

    1991-01-01

    The present status of investigation of acid rain, stratospheric ozone depletion and greenhouse effect and their relations to radiation exposure are reported. Soil acidification increases transfer rates of radioactivities to plants which increases the population dose. There are two types of ozone depletion, conventional type and ozone hole type and the latter is much more serious than the former. In the greenhouse effect, although there are large uncertainties both in theoretical and observational sides, present predictions about the global warming will not be very far from reality. Environmental effects are wide-ranging and serious. Radon and thoron exhalation rates are affected by the global warming. The influence of the greenhouse effect on ozone depletion is to suppress depletion for conventional type and enhance depletion for ozone hole type. (author) 65 refs

  17. Prior video game exposure does not enhance robotic surgical performance.

    Science.gov (United States)

    Harper, Jonathan D; Kaiser, Stefan; Ebrahimi, Kamyar; Lamberton, Gregory R; Hadley, H Roger; Ruckle, Herbert C; Baldwin, D Duane

    2007-10-01

    Prior research has demonstrated that counterintuitive laparoscopic surgical skills are enhanced by experience with video games. A similar relation with robotic surgical skills has not been tested. The purpose of this study was to determine whether prior video-game experience enhances the acquisition of robotic surgical skills. A series of 242 preclinical medical students completed a self-reported video-game questionnaire detailing the frequency, duration, and peak playing time. The 10 students with the highest and lowest video-game exposure completed a follow-up questionnaire further quantifying video game, sports, musical instrument, and craft and hobby exposure. Each subject viewed a training video demonstrating the use of the da Vinci surgical robot in tying knots, followed by 3 minutes of proctored practice time. Subjects then tied knots for 5 minutes while an independent blinded observer recorded the number of knots tied, missed knots, frayed sutures, broken sutures, and mechanical errors. The mean playing time for the 10 game players was 15,136 total hours (range 5,840-30,000 hours). Video-game players tied fewer knots than nonplayers (5.8 v 9.0; P = 0.04). Subjects who had played sports for at least 4 years had fewer mechanical errors (P = 0.04), broke fewer sutures (P = 0.01), and committed fewer total errors (P = 0.01). Similarly, those playing musical instruments longer than 5 years missed fewer knots (P = 0.05). In the extremes of video-game experience tested in this study, game playing was inversely correlated with the ability to learn robotic suturing. This study suggests that advanced surgical skills such as robotic suturing may be learned more quickly by athletes and musicians. Prior extensive video-game exposure had a negative impact on robotic performance.

  18. Ozone exposure, defoliation of beech (Fagus sylvatica L.) and visible foliar symptoms on native plants in selected plots of South-Western Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, Marco [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: m.ferretti@linnaea.it; Calderisi, Marco [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: calderisi@chemiometria.it; Bussotti, Filippo [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: filippo.bussotti@unifi.it

    2007-02-15

    The relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in South-Western Europe in the years 2000-2002. Relationships between defoliation of beech and O{sub 3} (seasonal mean, 2-week maximum, AOT40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). Different multiple regression techniques were used. The four models generated (R {sup 2} = 0.71-0.85, explained variance in cross-validation 61-78%) identified several significant predictors of defoliation, with AOT40 (p = 0.008) and foliar content of phosphorous (p = 0.0002-0.0004) being common to all models. The autocorrelation model (R {sup 2} = 0.55; p < 0.0001) was used to calculate expected defoliation on the basis of the previous year's defoliation, and model predictions were used as an estimate of expected defoliation under constant site and environmental condition. Residuals (predicted-measured) plotted against current AOT40 shows that a possible effect of ozone occurs only at very high AOT40 (>35,000 ppbh). O{sub 3}-like visible foliar symptoms were recorded on 65 species at 47% of the common monitoring sites in 2001 and 38% in 2002. No relationship was found between O{sub 3} exposure, frequency of symptomatic sites and frequency of species with symptoms (R {sup 2} = 0.11; p > 0.05). A number of questions related to the ecological and methodological basis of the survey were identified. Inherent sampling and non-sampling errors and multicollinearity of the data suggest great caution when examining results obtained from mensurational, correlative studies. - Ozone AOT40 was identified as a significant predictor of defoliation of beech, but a limited relationship was found between ozone exposure and visible symptoms on native vegetation.

  19. Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

    International Nuclear Information System (INIS)

    Ribas, Angela; Pen-tilde uelas, Josep; Elvira, Susana; Gimeno, Benjamin S.

    2005-01-01

    Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O 3 ) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb v of O 3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of δ 13 C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in δ 15 N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, δ 15 N, chlorophyll, leaf area, LMA and biomass occurred at ambient O 3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in

  20. Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, and growth of young spruce trees (Picea abies)

    International Nuclear Information System (INIS)

    Thomas, V.F.D.; Braun, S.; Flueckiger, W.

    2005-01-01

    Spruce saplings were grown under different nitrogen fertilization regimes in eight chamberless fumigation systems, which were fumigated with either charcoal-filtered (F) or ambient air (O 3 ). After the third growing season trees were harvested for biomass and non-structural carbohydrate analysis. Nitrogen had an overall positive effect on the investigated plant parameters, resulting in increased shoot elongation, biomass production, fine root soluble carbohydrate concentrations, and also slightly increased starch concentrations of stems and roots. Only needle starch concentrations and fine root sugar alcohol concentrations were decreased. Ozone fumigation resulted in needle discolorations and affected most parameters negatively, including decreased shoot elongation and decreased starch concentrations in roots, stems, and needles. In fine roots, however, soluble carbohydrate concentrations remained unaffected or increased by ozone fumigation. The only significant interaction was an antagonistic effect on root starch concentrations, where higher nitrogen levels alleviated the negative impact of ozone. - Simultaneous ozone fumigation and nitrogen fertilization have no synergistic impacts on carbohydrate concentrations, biomass, or growth of Picea abies saplings

  1. Minor effects of long-term ozone exposure on boreal peatland species Eriophorum vaginatum and Sphagnum papillosum

    DEFF Research Database (Denmark)

    Mörsky, SK; Haapala, JK; Rinnan, Riikka

    2011-01-01

    The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded...

  2. Effects of maternal high-fat diet and sedentary lifestyle on susceptibility of adult offspring to ozone exposure in rats

    Science.gov (United States)

    Epidemiological and experimental data suggest that obesity exacerbates the health effects of air pollutants such as ozone (O3). Maternal inactivity and calorically rich diets lead to offspring that show signs of obesity. Exacerbated O3 susceptibility of offspring could thus be m...

  3. A critical review and analysis of the use of exposure- and flux-based ozone indices for predicting vegetation effects

    Science.gov (United States)

    Robert C. Musselman; Allen S. Lefohn; William J. Massman; Robert L. Heath

    2006-01-01

    Early studies of plant response to ozone (O3) utilized concentration-based metrics, primarily by summarizing the commonly monitored hourly average data sets. Research with the O3 concentration parameter led to the recognition that both peak concentrations and cumulative effects are important when relating plant response to O3. The US and Canada currently use O3...

  4. Measurement of Ozone Production Sensor

    Directory of Open Access Journals (Sweden)

    M. Cazorla

    2010-05-01

    Full Text Available A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS, measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO2 to O3, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do in the sample chamber. The air flows that exit the two chambers are sampled by an ozone monitor operating in differential mode so that the difference between the two ozone signals, divided by the exposure time in the chambers, gives the ozone production rate. High-efficiency conversion of NO2 to O3 prior to detection in the ozone monitor accounts for differences in the NOx photostationary state that can occur in the two chambers. The MOPS measures the ozone production rate, but with the addition of NO to the sampled air flow, the MOPS can be used to study the sensitivity of ozone production to NO. Preliminary studies with the MOPS on the campus of the Pennsylvania State University show the potential of this new technique.

  5. Some technologically enhanced exposures to natural radiation environment in India

    International Nuclear Information System (INIS)

    Lalit, B.Y.; Shukla, V.K.; Ramachandran, T.V.; Mishra, U.C.

    1982-01-01

    A summary of results of gamma spectrometric measurements of natural radioactivity in a number of coal and flyash samples from thermal power plants and phosphatic fertilizer samples collected from various fertilizer plants in India are presented. These constitute the sources of technologically enhanced exposures to natural radiation. A brief description of sampling and measurement procedures is given. The radiation doses to the population from coal burning for electricity generation have been calculated using the method outlined in UNSCEAR report of 1979 with corrections for local population density. The external radiation dose to the farmers has been calculated on the basis of usage of phosphatic fertilizers for rice, wheat, millets and sugarcane crops for the normal agricultural practices

  6. Repeated exposure to enhanced UV-B radiation in successive generations increases developmental instability (leaf fluctuating asymmetry) in a desert annual

    International Nuclear Information System (INIS)

    Midgley, G.F.; Wand, S.J.E.; Musil, C.F.

    1998-01-01

    Populations of the desert annual Dimorphotheca sinuata, derived from a common seed stock, were exposed concurrently over four successive generations to either ambient (representing no stratospheric ozone depletion) or elevated (representing 20% stratospheric ozone depletion) UV-B levels during their complete life cycle. Leaf fluctuating asymmetry (FA) was measured in populations of plants grown from seeds of selected generations which had experienced different UV-B exposure histories, and from seeds collected from a wild population of this species which grows in a naturally enhanced UV-B environment. These measured plants had been grown in a greenhouse under essentially UV-B-free conditions. Leaf FA was significantly increased by greater numbers of enhanced UV-B exposures in the parentage of the seed. There was a linear to exponential dose–response relationship between number of UV-B exposure iterations in seed parentage and leaf FA, suggesting that damage to DNA caused by UV-B exposure during plant development may not be fully repaired, and thus be inherited by offspring and accumulated over successive generations in this species. Leaf FA of plants grown from seed from the wild population was not significantly greater than that of control plants whose parentage experienced only ambient UV-B exposures, although this negative result may have been due to low sampling intensity and measurement resolution, and the relatively low UV-B enhancement experienced by the wild population. We conclude that leaf FA may constitute a relatively sensitive yet inexpensive means of quantifying UV-B damage to plants. (author)

  7. Tree age dependence and within-canopy variation of leaf gas exchange and antioxidative defence in Fagus sylvatica under experimental free-air ozone exposure

    International Nuclear Information System (INIS)

    Herbinger, K.; Then, Ch.; Loew, M.; Haberer, K.; Alexous, M.; Koch, N.; Remele, K.; Heerdt, C.; Grill, D.; Rennenberg, H.; Haeberle, K.-H.; Matyssek, R.; Tausz, M.; Wieser, G.

    2005-01-01

    We characterized leaf gas exchange and antioxidative defence of two-year-old seedlings and 60-year-old trees of Fagus sylvatica exposed to ambient (1xO 3 ) or two-fold ambient (2xO 3 ) O 3 concentrations (maximum of 150 ppb) in a free-air canopy exposure system throughout the growing season. Decline in photosynthesis from sun-exposed to shaded conditions was more pronounced in adult than juvenile trees. Seedling leaves and leaves in the sun-exposed canopy had higher stomatal conductance and higher internal CO 2 concentrations relative to leaves of adult trees and leaves in shaded conditions. There was a weak overall depression of photosynthesis in the 2xO 3 variants across age classes and canopy positions. Pigment and tocopherol concentrations of leaves were significantly affected by canopy position and tree age, whereas differences between 1xO 3 and 2xO 3 regimes were not observed. Glutathione concentrations were significantly increased under 2xO 3 across both age classes and canopy levels. Seedlings differed from adult trees in relevant physiological and biochemical traits in ozone response. The water-soluble antioxidative systems responded most sensitively to 2xO 3 without regard of tree age or canopy position. - Ozone effects on leaf gas exchange and antioxidative systems of beech across tree age and canopy level were investigated in a free air exposure system

  8. Tree age dependence and within-canopy variation of leaf gas exchange and antioxidative defence in Fagus sylvatica under experimental free-air ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Herbinger, K. [Institut fuer Pflanzenwissenschaften, Universitaet Graz, Schubertstrasse 51, A-8010 Graz (Austria)]. E-mail: karin.herbinger@uni-graz.at; Then, Ch. [Bundesamt und Forschungszentrum fuer Wald, Abteilung Forstpflanzenphysiologie, Rennweg 1, A-6020 Innsbruck (Austria)]|[Lehrstuhl fuer Oekophysiologie der Pflanzen, Technische Universitaet Muenchen, Life Sciences Center Weihenstephan, Am Hochanger 13, D-85354 Freising (Germany); Loew, M.; Koch, N. [Lehrstuhl fuer Oekophysiologie der Pflanzen, Technische Universitaet Muenchen, Life Sciences Center Weihenstephan, Am Hochanger 13, D-85354 Freising (Germany); Haberer, K.; Alexous, M. [Institut fuer Forstbotanik und Baumphysiologie, Universitaet Freiburg, Georges-Koehler-Allee 053/054, D-79085 Freiburg (Germany); Remele, K. [Institut fuer Pflanzenwissenschaften, Universitaet Graz, Schubertstrasse 51, A-8010 Graz (Austria); Heerdt, C. [Lehrstuhl fuer Bioklimatologie und Immissionsforschung, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Grill, D. [Institut fuer Pflanzenwissenschaften, Universitaet Graz, Schubertstrasse 51, A-8010 Graz (Austria); Rennenberg, H. [Institut fuer Forstbotanik und Baumphysiologie, Universitaet Freiburg, Georges-Koehler-Allee 053/054, D-79085 Freiburg (Germany); Haeberle, K.-H.; Matyssek, R. [Lehrstuhl fuer Oekophysiologie der Pflanzen, Technische Universitaet Muenchen, Life Sciences Center Weihenstephan, Am Hochanger 13, D-85354 Freising (Germany); Tausz, M. [Institut fuer Pflanzenwissenschaften, Universitaet Graz, Schubertstrasse 51, A-8010 Graz (Austria)]|[[School of Forest and Ecosystem Science, University of Melbourne, Water Street, Creswick, Vic. 3363 (Australia); Wieser, G. [Bundesamt und Forschungszentrum fuer Wald, Abteilung Forstpflanzenphysiologie, Rennweg 1, A-6020 Innsbruck (Austria)

    2005-10-15

    We characterized leaf gas exchange and antioxidative defence of two-year-old seedlings and 60-year-old trees of Fagus sylvatica exposed to ambient (1xO{sub 3}) or two-fold ambient (2xO{sub 3}) O{sub 3} concentrations (maximum of 150 ppb) in a free-air canopy exposure system throughout the growing season. Decline in photosynthesis from sun-exposed to shaded conditions was more pronounced in adult than juvenile trees. Seedling leaves and leaves in the sun-exposed canopy had higher stomatal conductance and higher internal CO{sub 2} concentrations relative to leaves of adult trees and leaves in shaded conditions. There was a weak overall depression of photosynthesis in the 2xO{sub 3} variants across age classes and canopy positions. Pigment and tocopherol concentrations of leaves were significantly affected by canopy position and tree age, whereas differences between 1xO{sub 3} and 2xO{sub 3} regimes were not observed. Glutathione concentrations were significantly increased under 2xO{sub 3} across both age classes and canopy levels. Seedlings differed from adult trees in relevant physiological and biochemical traits in ozone response. The water-soluble antioxidative systems responded most sensitively to 2xO{sub 3} without regard of tree age or canopy position. - Ozone effects on leaf gas exchange and antioxidative systems of beech across tree age and canopy level were investigated in a free air exposure system.

  9. A difference gel electrophoresis study on thylakoids isolated from poplar leaves reveals a negative impact of ozone exposure on membrane proteins.

    Science.gov (United States)

    Bohler, Sacha; Sergeant, Kjell; Hoffmann, Lucien; Dizengremel, Pierre; Hausman, Jean-Francois; Renaut, Jenny; Jolivet, Yves

    2011-07-01

    Populus tremula L. x P. alba L. (Populus x canescens (Aiton) Smith), clone INRA 717-1-B4, saplings were subjected to 120 ppb ozone exposure for 28 days. Chloroplasts were isolated, and the membrane proteins, solubilized using the detergent 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC), were analyzed in a difference gel electrophoresis (DiGE) experiment comparing control versus ozone-exposed plants. Extrinsic photosystem (PS) proteins and adenosine triphosphatase (ATPase) subunits were detected to vary in abundance. The general trend was a decrease in abundance, except for ferredoxin-NADP(+) oxidoreductase (FNR), which increased after the first 7 days of exposure. The up-regulation of FNR would increase NAPDH production for reducing power and detoxification inside and outside of the chloroplast. Later on, FNR and a number of PS and ATPase subunits decrease in abundance. This could be the result of oxidative processes on chloroplast proteins but could also be a way to down-regulate photochemical reactions in response to an inhibition in Calvin cycle activity.

  10. Pre-exposure to moving form enhances static form sensitivity.

    Directory of Open Access Journals (Sweden)

    Thomas S A Wallis

    Full Text Available BACKGROUND: Motion-defined form can seem to persist briefly after motion ceases, before seeming to gradually disappear into the background. Here we investigate if this subjective persistence reflects a signal capable of improving objective measures of sensitivity to static form. METHODOLOGY/PRINCIPAL FINDINGS: We presented a sinusoidal modulation of luminance, masked by a background noise pattern. The sinusoidal luminance modulation was usually subjectively invisible when static, but visible when moving. We found that drifting then stopping the waveform resulted in a transient subjective persistence of the waveform in the static display. Observers' objective sensitivity to the position of the static waveform was also improved after viewing moving waveforms, compared to viewing static waveforms for a matched duration. This facilitation did not occur simply because movement provided more perspectives of the waveform, since performance following pre-exposure to scrambled animations did not match that following pre-exposure to smooth motion. Observers did not simply remember waveform positions at motion offset, since removing the waveform before testing reduced performance. CONCLUSIONS/SIGNIFICANCE: Motion processing therefore interacts with subsequent static visual inputs in a way that can improve performance in objective sensitivity measures. We suggest that the brief subjective persistence of motion-defined forms that can occur after motion offsets is a consequence of the decay of a static form signal that has been transiently enhanced by motion processing.

  11. Microcystis aeruginosa-laden water treatment using enhanced coagulation by persulfate/Fe(II), ozone and permanganate: Comparison of the simultaneous and successive oxidant dosing strategy.

    Science.gov (United States)

    Liu, Bin; Qu, Fangshu; Chen, Wei; Liang, Heng; Wang, Tianyu; Cheng, Xiaoxiang; Yu, Huarong; Li, Guibai; Van der Bruggen, Bart

    2017-11-15

    In this study, the application of enhanced coagulation with persulfate/Fe(II), permanganate and ozone for Microcystis-laden water treatment was investigated. Two oxidant dosage strategies were compared in terms of the organic removal performance: a simultaneous dosing strategy (SiDS) and a successive dosing strategy (SuDS). To optimize the oxidant species, oxidant doses and oxidant dosage strategy, the zeta potential, floc size and dimension fraction, potassium release and organic removal efficiency during the coagulation of algae-laden water were systematically investigated and comprehensively discussed. Ozonation causes most severe cell lysis and reduces organic removal efficiency because it releases intracellular organics. Moreover, ozonation can cause the release of odor compounds such as 2-methylisoborneol (2-MIB) and geosmin (GSM). With increasing doses, the performance of pollutant removal by coagulation enhanced by persulfate/Fe(II) or permanganate did not noticeably improve, which suggests that a low dosage of persulfate/Fe(II) and permanganate is the optimal strategy to enhance coagulation of Microcystis-laden water. The SiDS performs better than the SuDS because more Microcystis cell lysis occurs and less DOC is removed when oxidants are added before the coagulants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    Energy Technology Data Exchange (ETDEWEB)

    Olbrich, Maren, E-mail: maren.olbrich@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Gerstner, Elke; Bahnweg, Guenther [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Matyssek, Rainer [Technische Universitaet Muenchen, Ecophysiology of Plants, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Heller, Werner; Ernst, Dieter [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  13. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    International Nuclear Information System (INIS)

    Olbrich, Maren; Gerstner, Elke; Bahnweg, Guenther; Haeberle, Karl-Heinz; Matyssek, Rainer; Welzl, Gerhard; Heller, Werner; Ernst, Dieter

    2010-01-01

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  14. Ozone health effects

    International Nuclear Information System (INIS)

    Easterly, C.

    1994-01-01

    Ozone is a principal component of photochemical air pollution endogenous to numerous metropolitan areas. It is primarily formed by the oxidation of NOx in the presence of sunlight and reactive organic compounds. Ozone is a highly active oxidizing agent capable of causing injury to the lung. Lung injury may take the form of irritant effects on the respiratory tract that impair pulmonary function and result in subjective symptoms of respiratory discomfort. These symptoms include, but are not limited to, cough and shortness of breath, and they can limit exercise performance. The effects of ozone observed in humans have been primarily limited to alterations in respiratory function, and a range of respiratory physiological parameters have been measured as a function of ozone exposure in adults and children. These affects have been observed under widely varying (clinical experimental and environmental settings) conditions

  15. Improved functionality of graphene and carbon nanotube hybrid foam architecture by UV-ozone treatment

    Science.gov (United States)

    Wang, Wei; Ruiz, Isaac; Lee, Ilkeun; Zaera, Francisco; Ozkan, Mihrimah; Ozkan, Cengiz S.

    2015-04-01

    Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability.Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06795a

  16. Characterization and isolation of some genes of the shikimate pathway in sensitive and resistant Centaurea jacea plants after ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Francini, A. [Dipartimento di Coltivazione e Difesa delle Specie Legnose ' Giovanni Scaramuzzi' , University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Nali, C. [Dipartimento di Coltivazione e Difesa delle Specie Legnose ' Giovanni Scaramuzzi' , University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy)], E-mail: cristina.nali@agr.unipi.it; Pellegrini, E.; Lorenzini, G. [Dipartimento di Coltivazione e Difesa delle Specie Legnose ' Giovanni Scaramuzzi' , University of Pisa, Via del Borghetto 80, 56124 Pisa (Italy)

    2008-01-15

    Centaurea jacea has been suggested as a potential bioindicator for ozone, but little is known about its intraspecific variation in sensitivity, especially at molecular level. The effects of ozone (200 ppb, 5 h) on sensitive and resistant lines of Centaurea have been investigated at the end of fumigation. Sensitive plants showed characteristic symptoms of injury in the form of diffuse discoloration stipples on leaves. A PCR-based approach was used to identify and isolate a partial-length cDNA coding for PAL and CHS genes. The northern analysis of PAL showed accumulation of transcript in both lines correlated with a typical increase of PAL activity (+41 and +91% in resistant and sensitive material, respectively, compared to controls). On the contrary, the transcripts of CHS, in resistant and sensitive plants, did not change after treatment. Total phenols were not affected by ozone, while anthocyanins were quickly utilised by resistant clone as antioxidant compounds. - Characterization and isolation of PAL and CHS genes in Centaurea jacea exposed to O{sub 3}.

  17. Intervertebral Foramen Injection of Ozone Relieves Mechanical Allodynia and Enhances Analgesic Effect of Gabapentin in Animal Model of Neuropathic Pain.

    Science.gov (United States)

    Luo, Wen-Jun; Yang, Fan; Yang, Fei; Sun, Wei; Zheng, Wei; Wang, Xiao-Liang; Wu, Fang-Fang; Wang, Jiang-Lin; Wang, Jia-Shuang; Guan, Su-Min; Chen, Jun

    2017-07-01

    In a 5-year follow-up study in a hospital in southern China, it was shown that intervertebral foramen (IVF) injection of ozone at the involved segmental levels could significantly alleviate paroxysmal spontaneous pain and mechanical allodynia in patients with chronic, intractable postherpetic neuralgia (PHN) and improve the quality of life. However, so far no proof-of-concept studies in animals have been available. This study was designed to investigate whether IVF ozone has an analgesic effect on animal models of neuropathic and inflammatory pain. Experimental trial in rats. Institute for Biomedical Sciences of Pain. By IVF injection, a volume of 50 µl containing 30 µg/mL ozone-oxygen mixture or 50 µl air was carried out on male Sprague-Dawley rats of naïve, inflammatory pain states produced by injections of either bee venom or complete Freud's adjuvant, and neuropathic pain state produced by spared nerve injury, respectively. The effects of IVF ozone on pain-related behaviors were evaluated for 2 weeks or one month. Then combined use of gabapentin (100 mg/1 kg body weight) with IVF ozone was evaluated in rats with neuropathic pain by intraperitoneal administration 5 days after the ozone treatment. Finally, the analgesic effects of another 4 drugs, AMD3100 (a CXCR4 antagonist), A-803467 (a selective Nav1.8 blocker), rapamycin (the mTOR inhibitor), and MGCD0103 (a selective histone deacetylase inhibitor) were evaluated for long term through IVF injection, respectively. (1) IVF injection of ozone at L4-5 was only effective in suppression of mechanical allodynia in rats with neuropathic pain but not with inflammatory pain; (2) the analgesic effects of IVF ozone lasted much longer (> 14 days) than other selective molecular target drugs (bee venom, complete Freud's adjuvant.

  18. Co-exposure to ultrafine particulate matter and ozone causes electrocardiogram changes indicative of increased arrhythmia risk in mice

    Science.gov (United States)

    Numerous studies have shown a relationship between acute air pollution exposure and increased risk for cardiovascular morbidity and mortality. Due to the inherent complexity of air pollution, recent studies have focused on co-exposures to better understand potential interactions....

  19. Susceptibility of adult and senescent brown norway rats to repeated ozone exposure: An assessment of behavior, serum biochemistry and cardiopulmonary function

    Science.gov (United States)

    Tropospheric ozone (03) is a pervasive air pollutant that produces pulmonary and cardiovascular dysfunction and there is growing evidence suggesting neurological dysfunction as well. Young and old individuals are generally recognized as being susceptible to ozone toxicity; howeve...

  20. Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, Angela [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: a.ribas@creaf.uab.es; Pen-tilde uelas, Josep [CSIC-CEAB-CREAF Ecophysiology Unit, CREAF-Center for Ecological Research and Forestry Applications, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: josep.penuelas@uab.es; Elvira, Susana [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain); Gimeno, Benjamin S. [CIEMAT, Avd. Complutense 22, 28040 Madrid (Spain)

    2005-03-01

    Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O{sub 3}) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb{sub v} of O{sub 3} (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of {delta}{sup 13}C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in {delta}{sup 15}N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, {delta}{sup 15}N, chlorophyll, leaf area, LMA and biomass occurred at ambient O{sub 3} concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence

  1. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Song Shuang; Yao Jie [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); He Zhiqiao [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)], E-mail: zqhe@zjut.edu.cn; Qiu Jianping; Chen Jianmeng [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2008-03-21

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm{sup 2}, salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%.

  2. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    International Nuclear Information System (INIS)

    Song Shuang; Yao Jie; He Zhiqiao; Qiu Jianping; Chen Jianmeng

    2008-01-01

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm 2 , salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%

  3. Depletion of stratospheric ozone over the Antarctic and Arctic: Responses of plants of polar terrestrial ecosystems to enhanced UV-B, an overview

    International Nuclear Information System (INIS)

    Rozema, Jelte; Boelen, Peter; Blokker, Peter

    2005-01-01

    Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to experimentally varied UV-B through supplementation or exclusion. In supplementation studies comparing ambient and above ambient UV-B, no effect on growth occurred. UV-B-induced DNA damage, as measured in polar bryophytes, is repaired overnight by photoreactivation. With UV exclusion, growth at near ambient may be less than at below ambient UV-B levels, which relates to the UV response curve of polar plants. UV-B screening foils also alter PAR, humidity, and temperature and interactions of UV with environmental factors may occur. Plant phenolics induced by solar UV-B, as in pollen, spores and lignin, may serve as a climate proxy for past UV. Since the Antarctic and Arctic terrestrial ecosystems differ essentially (e.g. higher species diversity and more trophic interactions in the Arctic), generalization of polar plant responses to UV-B needs caution. - Polar plant responses to UV-B may be different in the Arctic than Antarctic regions

  4. Impacts of ozone air pollution and temperature extremes on crop yields: Spatial variability, adaptation and implications for future food security

    Science.gov (United States)

    Tai, Amos P. K.; Val Martin, Maria

    2017-11-01

    Ozone air pollution and climate change pose major threats to global crop production, with ramifications for future food security. Previous studies of ozone and warming impacts on crops typically do not account for the strong ozone-temperature correlation when interpreting crop-ozone or crop-temperature relationships, or the spatial variability of crop-to-ozone sensitivity arising from varietal and environmental differences, leading to potential biases in their estimated crop losses. Here we develop an empirical model, called the partial derivative-linear regression (PDLR) model, to estimate the spatial variations in the sensitivities of wheat, maize and soybean yields to ozone exposures and temperature extremes in the US and Europe using a composite of multidecadal datasets, fully correcting for ozone-temperature covariation. We find generally larger and more spatially varying sensitivities of all three crops to ozone exposures than are implied by experimentally derived concentration-response functions used in most previous studies. Stronger ozone tolerance is found in regions with high ozone levels and high consumptive crop water use, reflecting the existence of spatial adaptation and effect of water constraints. The spatially varying sensitivities to temperature extremes also indicate stronger heat tolerance in crops grown in warmer regions. The spatial adaptation of crops to ozone and temperature we find can serve as a surrogate for future adaptation. Using the PDLR-derived sensitivities and 2000-2050 ozone and temperature projections by the Community Earth System Model, we estimate that future warming and unmitigated ozone pollution can combine to cause an average decline in US wheat, maize and soybean production by 13%, 43% and 28%, respectively, and a smaller decline for European crops. Aggressive ozone regulation is shown to offset such decline to various extents, especially for wheat. Our findings demonstrate the importance of considering ozone regulation

  5. Limonene and its ozone-initiated reaction products attenuate allergic lung inflammation in mice.

    Science.gov (United States)

    Hansen, Jitka S; Nørgaard, Asger W; Koponen, Ismo K; Sørli, Jorid B; Paidi, Maya D; Hansen, Søren W K; Clausen, Per Axel; Nielsen, Gunnar D; Wolkoff, Peder; Larsen, Søren Thor

    2016-11-01

    Inhalation of indoor air pollutants may cause airway irritation and inflammation and is suspected to worsen allergic reactions. Inflammation may be due to mucosal damage, upper (sensory) and lower (pulmonary) airway irritation due to activation of the trigeminal and vagal nerves, respectively, and to neurogenic inflammation. The terpene, d-limonene, is used as a fragrance in numerous consumer products. When limonene reacts with the pulmonary irritant ozone, a complex mixture of gas and particle phase products is formed, which causes sensory irritation. This study investigated whether limonene, ozone or the reaction mixture can exacerbate allergic lung inflammation and whether airway irritation is enhanced in allergic BALB/cJ mice. Naïve and allergic (ovalbumin sensitized) mice were exposed via inhalation for three consecutive days to clean air, ozone, limonene or an ozone-limonene reaction mixture. Sensory and pulmonary irritation was investigated in addition to ovalbumin-specific antibodies, inflammatory cells, total protein and surfactant protein D in bronchoalveolar lavage fluid and hemeoxygenase-1 and cytokines in lung tissue. Overall, airway allergy was not exacerbated by any of the exposures. In contrast, it was found that limonene and the ozone-limonene reaction mixture reduced allergic inflammation possibly due to antioxidant properties. Ozone induced sensory irritation in both naïve and allergic mice. However, allergic but not naïve mice were protected from pulmonary irritation induced by ozone. This study showed that irritation responses might be modulated by airway allergy. However, aggravation of allergic symptoms was observed by neither exposure to ozone nor exposure to ozone-initiated limonene reaction products. In contrast, anti-inflammatory properties of the tested limonene-containing pollutants might attenuate airway allergy.

  6. Dissolution enhancement and mathematical modeling of removal of residual trichloroethene in sands by ozonation during flushing with micro-nano-bubble solution

    Science.gov (United States)

    Sung, Menghau; Teng, Chun-Hao; Yang, Tsung-Hsien

    2017-07-01

    Soil flushing using micro-nano-sized bubbles (MNB) in water as the flushing solution was tested in laboratory sand columns for the cleanup of residual trichloroethene (TCE) non-aqueous-phase-liquid (NAPL). Experiments considering flushing with MNB as well as ozone MNB (OZMNB) in water to treat soils contaminated with residual TCE liquid were conducted to examine effects of ozone on dissolution enhancement. The degrees of residual TCE saturation in soils, ranging from 0.44% to 7.6%, were tested. During flushings, aqueous TCE concentrations at the column exit were monitored and TCE masses remained in the columns after flushing were determined. Experimental results between runs with MNB and OZMNB in water revealed that dissolution enhancement was dependent on residual saturation conditions, and the maximum enhancement was around 9%. Governing equations consisting of three coupled partial differential equations (PDEs) were developed to model the system, and high-order finite difference (HOFD) method was employed to solve these PDEs. From mathematical modeling of reactive mass transfer under low residual saturation conditions (0.44% and 1.9%), experimental data were simulated and important controlling mechanisms were identified. It was concluded that a specific parameter pertinent to NAPL-water interfacial area in the Sherwood number had to be modified to satisfactorily describe the dissolution of TCE in the presence of MNB in water.

  7. Ozonation of piggery wastewater for enhanced removal of contaminants by S. quadricauda and the impact on organic characteristics.

    Science.gov (United States)

    Kim, Hyun-Chul; Choi, Wook Jin; Maeng, Sung Kyu; Kim, Hyung Joo; Kim, Han Soo; Song, Kyung Guen

    2014-05-01

    The feasibility of using ozonation pretreatment was investigated for a better performance of post microalgae-based wastewater remediation when treating piggery effluent which was anaerobically digested and subsequently micro-filtered. Ozonation pretreatment at a dose of 1.1mg-O3 mg-C(-1) or higher significantly improved the transmittance of light illumination through the mixed liquor by decolorizing the piggery effluent as culture media, which resulted in increasing both the productivity of algal biomass and the associated removal of inorganic nutrients from the effluent. Ozonation also converted refractory organic constituents in the piggery effluent to a large number of biodegradable fractions via both partial-mineralization and low-molecularization. These fractions were facilely removed through biological assimilation during the mixotrophic cultivation of a microalga S. quadricauda. The results revealed that ozonation could be one of the most promising strategies for the pretreatment of highly-colored piggery effluent prior to algae-based wastewater treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Fouling reduction by ozone-enhanced backwashing process in ultrafiltration of petroleum-based oil in water emulsion

    Science.gov (United States)

    Aryanti, Nita; Prihatiningtyas, Indah; Kusworo, Tutuk Djoko

    2017-06-01

    Ultrafiltration membrane has been successfully applied for oily waste water treatment. However, one significant drawback of membrane technology is fouling which is responsible for permeate flux decline as well as reducing membrane performance. One method commonly used to reduce fouling is a backwashing process. The backwashing is carried out by a push of reversed flow from permeate side to the feed side of a membrane to remove fouling on the membrane pore and release fouling release fouling layer on the external side. However, for adsorptive fouling, the backwashing process was not effective. On the other hand, Ozone demonstrated great performance for reducing organics fouling. Hence this research was focused on backwashing process with ozone for removing fouling due to ultrafiltration of petroleum based oil emulsion. Gasoline and diesel oil were selected as dispersed phase, while as continuous phase was water added with Tween 80 as a surfactant. This research found that the Ozone backwashing was effective to improve flux recovery. In ultrafiltration of gasoline emulsion, the flux recovery after Ozone backwashing was in the range of 42-74%. For ultrafiltration of diesel oil emulsion, the permeate flux recovery was about 35-84%. In addition, foulant deposition was proposed and predicting that foulant deposition for ultrafiltration of gasoline-in-water emulsion was surfactant as the top layer and the oil was underneath the surfactant. On the other hand, for ultrafiltration of diesel oil-in-water emulsion, the oil was predicted as a top layer above the surfactant foulant.

  9. Impacts of ozone on trees and crops

    International Nuclear Information System (INIS)

    Felzer, B.S.; Cronina, T.; Melillo, J.M.; Reilly, J.M.; Xiaodong, Wang

    2007-01-01

    In this review article, we explore how surface-level ozone affects trees and crops with special emphasis on consequences for productivity and carbon sequestration. Vegetation exposure to ozone reduces photosynthesis, growth, and other plant functions. Ozone formation in the atmosphere is a product of NO x , which are also a source of nitrogen deposition. Reduced carbon sequestration of temperate forests resulting from ozone is likely offset by increased carbon sequestration from nitrogen fertilization. However, since fertilized crop-lands are generally not nitrogen-limited, capping ozone-polluting substances in the USA, Europe, and China can reduce future crop yield loss substantially. (authors)

  10. Simulated root dynamics of a 160-year-old sugar maple (Acer saccharum Marsh.) tree with and without ozone exposure using the TREGRO model.

    Science.gov (United States)

    Retzlaff, W. A.; Weinstein, D. A.; Laurence, J. A.; Gollands, B.

    1996-01-01

    Because of difficulties in directly assessing root responses of mature forest trees exposed to atmospheric pollutants, we have used the model TREGRO to analyze the effects of a 3- and a 10-year exposure to ozone (O(3)) on root dynamics of a simulated 160-year-old sugar maple (Acer saccharum Marsh.) tree. We used existing phenological, allometric, and growth data to parameterize TREGRO to produce a simulated 160-year-old tree. Simulations were based on literature values for sugar maple fine root production and senescence and the photosynthetic responses of sugar maple seedlings exposed to O(3) in open-top chambers. In the simulated 3-year exposure to O(3), 2 x ambient atmospheric O(3) concentrations reduced net carbon (C) gain of the 160-year-old tree. This reduction occurred in the C storage pools (total nonstructural carbohydrate, TNC), with most of the reduction occurring in coarse (woody) roots. Total fine root production and senescence were unaffected by the simulated 3-year exposure to O(3). However, extending the simulated O(3) exposure period to 10 years depleted the TNC pools of the coarse roots and reduced total fine root production. Similar reductions in TNC pools have been observed in forest-grown sugar maple trees exhibiting symptoms of stress. We conclude that modeling can aid in evaluating the belowground response of mature forest trees to atmospheric pollution stress and could indicate the potential for gradual deterioration of tree health under conditions of long-term stress, a situation similar to that underlying the decline of sugar maple trees.

  11. Three-dimensional MnO{sub 2} porous hollow microspheres for enhanced activity as ozonation catalysts in degradation of bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiuqin; Wan, Yifeng; Huang, Yajing [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); He, Chun, E-mail: hechun@mail.sysu.edu.cn [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275 (China); Zhang, Zaili; He, Zhuoyan; Hu, Lingling; Zeng, Jiawei [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Shu, Dong, E-mail: dshu@scnu.edu.cn [Key Lab of Technology on Electrochemical Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou, 510006 (China)

    2017-01-05

    Highlights: • 3D MnO{sub 2} porous hollow microspheres (PHMSs) are prepared by a self-template process. • MnO{sub 2} PHMSs with excellent adsorption and catalytic ozonation performance for BPA. • MnO{sub 2} PHMSs show enhanced activity due to hollow-mesoporous shell spherical structure. • O{sub 2}{sup −} and ·OH are reactive species to induce effective catalytic ozonation of BPA. - Abstract: Three-dimensional (3D) MnO{sub 2} porous hollow microspheres (δ- and α- MnO{sub 2} PHMSs), with high adsorption and catalytic ozonation performance, were synthesized by a self-template (MnCO{sub 3} microspheres) process at room temperature. The synthesized MnO{sub 2} PHMSs were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area. The results showed that PHMSs exhibit the excellent adsorption ability and catalytic activity owning to their hollow spherical structure, mesoporous shell and well-defined interior voids, leading to the strong adsorption for bisphenol A (BPA) and the retention of O{sub 3} molecules on catalyst. Moreover, the catalytic performance of α-MnO{sub 2} PHMSs was better than that of δ-MnO{sub 2} PHMSs which was attributed to the richer lattice oxygen of α-MnO{sub 2} PHMSs to accelerate O{sub 3} decomposition by producing more reactive oxidative species. The degradation efficiency of BPA using 3D α-MnO{sub 2} PHMSs was more than 90% in the presence of ozone within 30 min reaction time. The probe tests for reactive oxidative species (ROSs) displayed that BPA degradation by catalytic ozonation is dominated by ·O{sub 2}{sup −} and ·OH in our present study. Furthermore, the organic compounds as intermediates of the degradation process were identified by LC/MS.

  12. SUM06 Index for Damage to Flora from Ozone

    Data.gov (United States)

    U.S. Environmental Protection Agency — In addition to health effects in humans, Ozone exposure also causes damage to plants. One index used in calculating the potential damage to plants from Ozone...

  13. Observation of abnormal mobility enhancement in multilayer MoS2 transistor by synergy of ultraviolet illumination and ozone plasma treatment

    Science.gov (United States)

    Guo, Junjie; Yang, Bingchu; Zheng, Zhouming; Jiang, Jie

    2017-03-01

    Mobility engineering through physical or chemical process is a fruitful approach for the atomically-layered two-dimensional electronic applications. Unfortunately, the usual process with either illumination or oxygen treatment would greatly deteriorate the mobility in two-dimensional MoS2 field-effect transistor (FET). Here, in this work, we report that the mobility can be abnormally enhanced to an order of magnitude by the synergy of ultraviolet illumination (UV) and ozone plasma treatment in multilayer MoS2 FET. This abnormal mobility enhancement is attributed to the trap passivation due to the photo-generated excess carriers during UV/ozone plasma treatment. An energy band model based on Schottky barrier modulation is proposed to understand the underlying mechanism. Raman spectra results indicate that the oxygen ions are incorporated into the surface of MoS2 (some of them are in the form of ultra-thin Mo-oxide) and can further confirm this proposed mechanism. Our results can thus provide a simple approach for mobility engineering in MoS2-based FET and can be easily expanded to other 2D electronic devices, which represents a significant step toward applications of 2D layered materials in advanced cost-effective electronics.

  14. Ozone decomposition

    Directory of Open Access Journals (Sweden)

    Batakliev Todor

    2014-06-01

    Full Text Available Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers. Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates

  15. Ozone modeling

    Energy Technology Data Exchange (ETDEWEB)

    McIllvaine, C M

    1994-07-01

    Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO{sub 2}), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NO{sub x} concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NO{sub x} coordinates of the point, known as the NMOC/NO{sub x} ratio. Results obtained by the described model are presented.

  16. Ozone modeling

    International Nuclear Information System (INIS)

    McIllvaine, C.M.

    1994-01-01

    Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO 2 ), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NO x concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NO x coordinates of the point, known as the NMOC/NO x ratio. Results obtained by the described model are presented

  17. A simple UV-ozone surface treatment to enhance photocatalytic performance of TiO 2 loaded polymer nanofiber membranes

    KAUST Repository

    Dilpazir, S.

    2016-01-29

    Homogeneously dispersed titanium dioxide loaded polyacrylonitrile nanofiber membranes with increased active mass loading, Ti3+ surface defects and hydrophilicity were fabricated by combining electrospinning and UV-ozone surface treatment. The photocatalytic activity improved by a factor of ∼2 and the kinetics of photodegradation switched from pseudo-first order to pseudo-second order with increasing TiO2 content with a maximum rate constant of 20.7 h-1. © The Royal Society of Chemistry 2016.

  18. Monitoring the consequences of decreased ozone protection: The NSF ultraviolet radiation monitoring network

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The effects of decreased protection from ultraviolet radiation are as troubling as the continuing depletion of stratospheric ozone. Evidence exists to clearly link ozone depletion to changes in the antarctic marine environment. Results of two 1992 papers are summarized here. Enhanced exposure to mid-range UV radiation was found to be affecting marine ecosystems with a recorded 6-12 percent reduction in primary productivity directly related to the ozone layer depletion. In another experiment, a model was developed indicating that the ozone hole could reduce near-surface photosynthesis by as much as 12-15 percent. The NSF UV monitoring system in place for these and other experiments uses a spectroradiometer, making hourly, high-resolution measurements of the distribution of UV surface irradiance

  19. Foliar injury responses of eleven plant species to ozone/sulfur dioxide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Tingey, D T; Reinert, R A; Dunning, J A; Heck, W W

    1973-01-01

    Eleven plant species were exposed to ozone and/or sulfur dioxide to determine if a mixture of the two gases enhanced foliar injury. Tobacco, radish, and alfalfa developed more injury that the additive injury of the single gases. In other species, such as cabbage, broccoli, and tomato, the foliar injury from mixed-gas exposures was additive or less than additive. Leaf injury from the ozone/sulfur dioxide mixture appeared as upper surface flecking, stipple, bifacial necrosis, and lower surface glazing and, in general, appeared similar to injury from oxidant or ozone. The concentrations of ozone and sulfur dioxide that caused plant injury were similar to those found in urban areas. These concentrations may result in yield losses to plants grown under field conditions.

  20. Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review

    OpenAIRE

    de Kleine, Rianne A.; Rothbaum, Barbara O.; van Minnen, Agnes

    2013-01-01

    There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD). Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. Th...

  1. Ozone Pollution

    Science.gov (United States)

    Known as tropospheric or ground-level ozone, this gas is harmful to human heath and the environment. Since it forms from emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx), these pollutants are regulated under air quality standards.

  2. Experimental study of ozone synthesis

    International Nuclear Information System (INIS)

    Garamoon, A A; Elakshar, F F; Nossair, A M; Kotp, E F

    2002-01-01

    A silent discharge ozonizer has been constructed with a design that enables the study of ozone concentration behaviour as a function of different parameters when oxygen used as a working gas. The behaviour of ozone concentration as a function of discharge current density has four characteristic regions. The concentration is enhanced by more than threefold whenever gas pressure is reduced by a factor of two. The flow rate of the working gas is a more effective parameter on ozone concentration than the gas pressure. When the flow rate is kept constant, and the pressure is decreased by 100%, the ozone concentration increases by only 10%. On the other hand, when the flow rate is decreased by 13%, the ozone concentration increases by 200%, whenever the gas pressure is kept constant. The concentration is nearly doubled when the gap space is increased by four times under the same conditions. The length of the discharge region, the thickness and the dielectric constant of the insulating materials are found to have a considerable effect on the generated ozone concentration. Also, the ozone concentration is ten times less when air is used instead of oxygen as a working gas. A maximum efficiency of 185 g/kWh, is obtained for the present system

  3. Protection of ash (Fraxinus excelsior) trees from ozone injury by ethylenediurea (EDU): Roles of biochemical changes and decreased stomatal conductance in enhancement of growth

    International Nuclear Information System (INIS)

    Paoletti, Elena; Contran, Nicla; Manning, William J.; Castagna, Antonella; Ranieri, Annamaria; Tagliaferro, Francesco

    2008-01-01

    Treatments with ethylenediurea (EDU) protect plants from ozone foliar injury, but the processes underlying this protection are poorly understood. Adult ash trees (Fraxinus excelsior), with or without foliar ozone symptoms in previous years, were treated with EDU at 450 ppm by gravitational trunk infusion in May-September 2005 (32.5 ppm h AOT40). At 30-day intervals, shoot growth, gas exchange, chlorophyll a fluorescence, and water potential were determined. In September, several biochemical parameters were measured. The protective influence of EDU was supported by enhancement in the number of leaflets. EDU did not contribute its nitrogen to leaf tissue as a fertiliser, as determined from lack of difference in foliar N between treatments. Both biochemical (increase in ascorbate-peroxidase and ascorbic acid, and decrease in apoplastic hydrogen peroxide) and biophysical (decrease in stomatal conductance) processes regulated EDU action. As total ascorbic acid increased only in the asymptomatic trees, its role in alleviating O 3 effects on leaf growth and visible injury is controversial. - Both biochemical and biophysical processes may regulate EDU action

  4. Long-term exposure to enhanced ultraviolet-B radiation in the sub-arctic does not cause oxidative stress in Vaccinium myrtillus

    International Nuclear Information System (INIS)

    Taulavuori, E.; Bäckman, M.; Taulavuori, K.; Gwynn-Jones, D.; Johanson, U.; Laine, K.; Callaghan, T.; Sonesson, M.; Björn, L.O.

    1998-01-01

    The aim of this work was to assess whether or not oxidative stress had developed in a dwarf shrub bilberry (Vaccinium myrtillus L.) under long-term exposure to enhanced levels of ultraviolet-B (u.v.-B) radiation. The bilberry plants were exposed to increased u.v.-B representing a 15 stratospheric ozone depletion for seven full growing seasons (19911997) at Abisko, Swedish Lapland (68N). The oxidative stress was assessed on leaves and stems by analysing ascorbate and glutathione concentrations, and activities of the closely related enzymes ascorbate peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2). The affects of autumnal leaf senescence and stem cold hardening on these variables were also considered. The results showed that the treatment caused scarcely any response in the studied variables, indicating that u.v.-B flux representing a 15 ozone depletion under clear sky conditions is not sufficient to cause oxidative stress in the bilberry. It is suggested that no strain was evoked since adaptation was possible under such u.v.-B increases. The studied variables did, however, respond significantly to leaf senescence and especially to stem cold hardening. (author)

  5. OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2010-03-01

    Full Text Available Ozone in the lower part of the atmosphere (troposphere, strong photochemical oxidant, is not directly emitted to the atmosphere but formed through a series of complex reactions. Ozone concentrations depends on ozone precursors air contamination (mainly nitrogen dioxide and non-methane volatile organic compounds and meteorological conditions (temperature and solar radiation. The main sectors emitted ozone precursors are road transport, power and heat generation plants, household (heating, industry, and petrol storage and distribution. Ozone and some of its precursors are also transported long distances in the atmosphere and are therefore considered a transboundary problem. As a result, the ozone concentrations are often low in busy urban areas and higher in suburban and rural areas. Nowadays, instead of particulate matter, ozone is one of the most widespread global air pollution problems. In and around urban areas, relatively large gradients of ozone can be observed. Because of its high reactivity in elevated concentrations ozone causes serious health problems and damage to ecosystems, agricultural crops and materials. Main ill-health endpoints as a results of ozone concentrations can be characterised as an effect of pulmonary and cardiovascular system, time morbidity and mortality series, development of atherosclerosis and asthma and finally reduction in life expectancy. The associations with increased daily mortality due to ozone concentrations are confirmed by many researches and epidemiological studies. Estimation of the level selected ill-health endpoints (mortality in total and due to cardiovascular and respiratory causes as a result of the short-term ozone exposure in Poland was the main aim of the project. Final results have been done based on estimation method elaborated by WHO, ozone measurements from National Air Quality Monitoring System and statistical information such as mortality rate and populations. All analysis have been done in

  6. Effect of trichloroethylene enhancement on deposition rate of low-temperature silicon oxide films by silicone oil and ozone

    Science.gov (United States)

    Horita, Susumu; Jain, Puneet

    2017-08-01

    A low-temperature silcon oxide film was deposited at 160 to 220 °C using an atmospheric pressure CVD system with silicone oil vapor and ozone gases. It was found that the deposition rate is markedly increased by adding trichloroethylene (TCE) vapor, which is generated by bubbling TCE solution with N2 gas flow. The increase is more than 3 times that observed without TCE, and any contamination due to TCE is hardly observed in the deposited Si oxide films from Fourier transform infrared spectra.

  7. Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review

    Directory of Open Access Journals (Sweden)

    Rianne A. de Kleine

    2013-10-01

    Full Text Available There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD. Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. The current review aims to give an overview of clinical studies on pharmacological enhancement of exposure-based treatment for PTSD. The working mechanisms, efficacy studies in PTSD patients, and clinical utility of four different pharmacological enhancers will be discussed: D-cycloserine, MDMA, hydrocortisone, and propranolol.

  8. Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review.

    Science.gov (United States)

    de Kleine, Rianne A; Rothbaum, Barbara O; van Minnen, Agnes

    2013-10-17

    There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD). Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in the improvement of exposure therapy efficacy for PTSD emerged. Basic research found evidence of the pharmacological enhancement of the underlying learning and memory processes of exposure therapy. The current review aims to give an overview of clinical studies on pharmacological enhancement of exposure-based treatment for PTSD. The working mechanisms, efficacy studies in PTSD patients, and clinical utility of four different pharmacological enhancers will be discussed: d-cycloserine, MDMA, hydrocortisone, and propranolol.

  9. Ozone-Induced Pulmonary Injury and Inflammation are Modulated by Adrenal-Derived Stress Hormones

    Science.gov (United States)

    Ozone exposure promotes pulmonary injury and inflammation. Previously we have characterized systemic changes that occur immediately after acute ozone exposure and are mediated by neuro-hormonal stress response pathway. Both HPA axis and sympathetic tone alterations induce the rel...

  10. Ozone depletion following future volcanic eruptions

    Science.gov (United States)

    Eric Klobas, J.; Wilmouth, David M.; Weisenstein, Debra K.; Anderson, James G.; Salawitch, Ross J.

    2017-07-01

    While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to increase total column ozone as halogen loading approaches preindustrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone layer is poorly known. Modeling four possible climate futures, we show that scenarios with the smallest increase in greenhouse gas concentrations lead to the greatest risk to ozone from heterogeneous chemical processing following future eruptions. We also show that the presence in the stratosphere of bromine from natural, very short-lived biogenic compounds is critically important for determining whether future eruptions will lead to ozone depletion. If volcanic eruptions inject hydrogen halides into the stratosphere, an effect not considered in current ozone assessments, potentially profound reductions in column ozone would result.

  11. Enhanced Enzymatic Hydrolysis and Structural Features of Corn Stover by NaOH and Ozone Combined Pretreatment

    Directory of Open Access Journals (Sweden)

    Wenhui Wang

    2018-05-01

    Full Text Available A two-step pretreatment using NaOH and ozone was performed to improve the enzymatic hydrolysis, compositions and structural characteristics of corn stover. Comparison between the unpretreated and pretreated corn stover was also made to illustrate the mechanism of the combined pretreatment. A pretreatment with 2% (w/w NaOH at 80 °C for 2 h followed by ozone treatment for 25 min with an initial pH 9 was found to be the optimal procedure and the maximum efficiency (91.73% of cellulose enzymatic hydrolysis was achieved. Furthermore, microscopic observation of changes in the surface structure of the samples showed that holes were formed and lignin and hemicellulose were partially dissolved and removed. X-ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR and Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS 13C-NMR were also used to characterize the chemical structural changes after the combined pretreatment. The results were as follows: part of the cellulose I structure was destroyed and then reformed into cellulose III, the cellulose crystal indices were also changed; a wider space between the crystal layer was observed; disruption of hydrogen bonds in cellulose and disruption of ester bonds in hemicellulose; cleavage of bonds linkage in lignin-carbohydrate complexes; removal of methoxy in lignin and hemicellulose. As a result, all these changes effectively reduced recalcitrance of corn stover and promoted subsequent enzymatic hydrolysis of cellulose.

  12. Ozone reaction on slime mold. [Physarum polycephalum

    Energy Technology Data Exchange (ETDEWEB)

    Kanoh, F.

    1972-01-01

    To determine the effect of ozone, the motive force responsible for protoplasmic streaming in the slime mold, Physarum polycephalum was measured by the Double chamber method which was developed by Kamiya. The effects of ozone on the motive force were investigated by comparison of the Dynamoplasmogram of controls with that of ozone exposure. In the case of high concentration exposure, thickening of plasmagel, inversion of the period of flow and reduction of the extreme point were observed. Succinoxidase of exposed homogenates showed stronger activity than that of controls. It is certain that the Pasteur reaction takes place when plasmodium is kept under high ozone exposure condition. It appears that ozone inhibited a part of the process of glycolysis. 32 references, 8 figures.

  13. Ozone sensitivity of plants in natural communities

    Energy Technology Data Exchange (ETDEWEB)

    Treshow, M; Stewart, D

    1973-07-01

    Field fumigation studies conducted in grassland, oak, aspen, and conifer, communities established the injury threshold of prevalent plant species to ozone. Several important species, including Bromus tectorum, Quercus gambelii, and Populus tremuloides, were injured by a single 2-hours exposure to 15 pphM ozone. Over half the perennial forbs and woody species studied were visibly injured at concentrations of 30 pphM ozone or less. It is postulated that lower concentrations at prolonged or repeated exposures to ozone may impair growth and affect community vigor and stability. Continued exposure of natural plant communities to ozone is expected to initiate major shifts in the plant composition of communities. 10 references, 4 figures, 1 table.

  14. Stratospheric ozone depletion: high arctic tundra plant species from Svalbard are not affected by enhanced UV-B after 7 years of UV-B supplementation in the field.

    NARCIS (Netherlands)

    Rozema, J.; Boelen, P.; Blokker, P.; Callaghan, T.V.; Solheim, B.; Zielke, M.

    2006-01-01

    The response of tundra plants to enhanced UV-B radiation simulating 15 and 30% ozone depletion was studied at two high arctic sites (Isdammen and Adventdalen, 78° N, Svalbard).The set-up of the UV-B supplementation systems is described, consisting of large and small UV lamp arrays, installed in 1996

  15. Enhanced UV exposure on a ski-field compared with exposures at sea level.

    Science.gov (United States)

    Allen, Martin; McKenzie, Richard

    2005-05-01

    Personal erythemal UV monitoring badges, which were developed to monitor the UV exposure of school children, were used to measure UV exposures received by one of the authors (MA) at the Mt Hutt ski-field, in New Zealand. These were then compared with measurements taken at the same times from a nearby sea level site in Christchurch city. The badges were designed to give instantaneous readings of erythemally-weighted (i.e., "sun burning") UV radiation and were cross-calibrated against meteorological grade UV instruments maintained by the National Institute of Water & Atmospheric Research (NIWA). All skiing and calibration days were clear and almost exclusively cloud free. It was found that the UV maxima for horizontal surfaces at the ski-field (altitude approximately 2 km) were 20-30% greater than at the low altitude site. Larger differences between the sites were observed when the sensor was oriented perpendicular to the sun. The personal doses of UV received by a sensor on the skier's lapel during two days of skiing activity were less than those received by a stationary detector on a horizontal surface near sea level. The exposures depended strongly on the time of year, and in mid-October the maximum UV intensity on the ski-field was 60% greater than in mid-September. The UV exposure levels experienced during skiing were smaller than the summer maxima at low altitudes.

  16. Foliar injury response of petunia and kidney bean to simultaneous and alternate exposures to ozone and PAN

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I.; Mayumi, H.; Yamazoe, F.

    1984-01-01

    Petunia at about 6 weeks old and kidney bean at two growing stages (6-7 days old and 16-18 days old) were exposed separately to O/sub 3/ (0-0.40 ppm) and PAN (0-0.25 ppm) for 4 h and to the mixture for the same time. In addition, petunia was exposed to O/sub 3/ (0.10-0.40 ppm) and then PAN (0.010-0.040 ppm) for 4 h, respectively. Foliar injury of petunia and kidney bean in exposures to the mixtures of O/sub 3/ and PAN was significantly smaller than that induced by each oxidant, with the exception of PAN injury on young leaves of 16-18 day-old kidney bean. The percentage of foliar injury caused by either of the mixed pollutants decreased with an increase of the concentration of the other oxidant, and was found to approximate a logarithmic function of the combined pollutant concentrations expressed as O/sub 3/ minum PAN or vice versa. Alternate exposures caused no additive or synergistic injuries. 23 references, 3 figures, 6 tables.

  17. Foliar injury response of petunia and kidney bean to simultaneous and alternate exposures to ozone and pan

    Science.gov (United States)

    Nouchi, Isamu; Mayumi, Hirokazu; Yamazoe, Fumio

    Petunia at about 6 weeks old and kidney bean at two growing stages (6-7 days old and 16-18 days old) were exposed separately to O 3, (0-0.40 ppm) and PAN (0-0.25 ppm) for 4 h and to the mixture for the same time. In addition, petunia was exposed to O, (0.10-0.40 ppm) and then PAN (0.010-0.040 ppm) for 4 h, respectively. Foliar injury of petunia and kidney bean in exposures to the mixtures of O 3 and PAN was significantly smaller than that induced by each oxidant, with the exception of PAN injury on young leaves of 16-18 day-old kidney bean. The percentage of foliar injury caused by either of the mixed pollutants decreased with an increase of the concentration of the other oxidant, and was found to approximate a logarithmic function of the combined pollutant concentrations expressed as O 3, minum PAN or vice versa. Alternate exposures caused no additive or synergistic injuries.

  18. Ozone modelling in Eastern Austria

    Energy Technology Data Exchange (ETDEWEB)

    Stohl, A.; Wotawa, G.; Kromp-Kolb, H. [Univ. of Agriculture, Vienna (Austria). Inst. of Meteorology and Physics; Winiwater, W. [Austrian Research Centre, Seibersdorf (Austria); Baumann, R.; Spangl, W. [Federal Environmental Agency, Vienna (Austria)

    1995-12-31

    High ozone concentrations are frequently observed in Eastern Austria, often exceeding local as well as international health standards, both for short-term as well as for long-term exposures. The maximum concentrations are produced in urban plumes, e.g. of the city of Vienna, whereas regional-scale transport and production of ozone is more important for the long-term concentrations. The Pannonian Ozone Project (POP) is an Austrian research initiative to model photochemical processes on a regional as well as on a local scale with a Lagrangian model to better understand the mechanisms leading to the high ozone concentrations and to develop abatement strategies. Up to now, focus has been on the regional scale. Aircraft, tethered balloon, tetroon and intensified ground measurements are carried out to validate the model. Although the major measurement campaign will be held in summer 1995, first results from a measurement campaign in summer 1994 are already available

  19. Ecological effects of exposure to enhanced levels of ionizing radiation.

    Science.gov (United States)

    Geras'kin, Stanislav A

    2016-10-01

    Irradiation of plants and animals can result in disruption of ecological relationships between the components of ecosystems. Such effects may act as triggers of perturbation and lead to consequences that may differ essentially from expected ones based on effects observed at the organismal level. Considerable differences in ecology and niches occupied by different species lead to substantial differences in doses of ionizing radiation absorbed by species, even when they all are present in the same environment at the same time. This is especially evident for contamination with α-emitting radionuclides. Radioactive contamination can be considered an ecological factor that is able to modify the resistance in natural populations. However, there are radioecological situations when elevated radioresistance does not evolve or persist. The complexity and non-linearity of the structure and functioning of ecosystems can lead to unexpected consequences of stress effects, which would appear harmless if they were assessed within the narrower context of organism-based traditional radioecology. Therefore, the use of ecological knowledge is essential for understanding responses of populations and ecosystems to radiation exposure. Integration of basic ecological principles in the design and implementation of radioecological research is essential for predicting radiation effects under rapidly changing environmental conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The TOMS V9 Algorithm for OMPS Nadir Mapper Total Ozone: An Enhanced Design That Ensures Data Continuity

    Science.gov (United States)

    Haffner, D. P.; McPeters, R. D.; Bhartia, P. K.; Labow, G. J.

    2015-12-01

    The TOMS V9 total ozone algorithm will be applied to the OMPS Nadir Mapper instrument to supersede the exisiting V8.6 data product in operational processing and re-processing for public release. Becuase the quality of the V8.6 data is already quite high, enchancements in V9 are mainly with information provided by the retrieval and simplifcations to the algorithm. The design of the V9 algorithm has been influenced by improvements both in our knowledge of atmospheric effects, such as those of clouds made possible by studies with OMI, and also limitations in the V8 algorithms applied to both OMI and OMPS. But the namesake instruments of the TOMS algorithm are substantially more limited in their spectral and noise characterisitics, and a requirement of our algorithm is to also apply the algorithm to these discrete band spectrometers which date back to 1978. To achieve continuity for all these instruments, the TOMS V9 algorithm continues to use radiances in discrete bands, but now uses Rodgers optimal estimation to retrieve a coarse profile and provide uncertainties for each retrieval. The algorithm remains capable of achieving high accuracy results with a small number of discrete wavelengths, and in extreme cases, such as unusual profile shapes and high solar zenith angles, the quality of the retrievals is improved. Despite the intended design to use limited wavlenegths, the algorithm can also utilitze additional wavelengths from hyperspectral sensors like OMPS to augment the retreival's error detection and information content; for example SO2 detection and correction of Ring effect on atmospheric radiances. We discuss these and other aspects of the V9 algorithm as it will be applied to OMPS, and will mention potential improvements which aim to take advantage of a synergy with OMPS Limb Profiler and Nadir Mapper to further improve the quality of total ozone from the OMPS instrument.

  1. Aviation-attributable ozone as a driver for changes in mortality related to air quality and skin cancer

    Science.gov (United States)

    Eastham, Sebastian D.; Barrett, Steven R. H.

    2016-11-01

    Aviation is a significant source of tropospheric ozone, which is a critical UV blocking agent, an indirect precursor to the formation of particulate matter, and a respiratory health hazard. To date, investigations of human health impacts related to aviation emissions have focused on particulate matter, and no global estimate yet exists of the combined health impact of aviation due to ozone, particulate matter and UV exposure changes. We use a coupled tropospheric-stratospheric chemical-transport model with a global aviation emissions inventory to estimate the total impact of aviation on all three risk factors. We find that surface ozone due to aviation emissions is maximized during hemispheric winter due to the greater wintertime chemical lifetime of ozone, but that a smaller enhancement of 0.5 ppbv occurs during summertime. This summertime increase results in an estimated 6,800 premature mortalities per year due to ozone exposure, over three times greater than previous estimates. During the winter maximum, interaction with high background NOx concentrations results in enhanced production of nitrate aerosol and increased annual average exposure to particulate matter. This ozone perturbation is shown to be the driving mechanism behind an additional 9,200 premature mortalities due to exposure to particulate matter. However, the increase in tropospheric ozone is also found to result in 400 fewer mortalities due to melanoma skin cancer in 2006. This is the first estimate of global melanoma mortality due to aviation, and the first estimate of skin cancer mortality impacts due to aviation using a global chemical transport model.

  2. Reconciliation of Halogen-Induced Ozone Loss with the Total-Column Ozone Record

    Science.gov (United States)

    Shepherd, T. G.; Plummer, D. A.; Scinocca, J. F.; Hegglin, M. I.; Fioletov, V. E.; Reader, M. C.; Remsberg, E.; von Clarmann, T.; Wang, H. J.

    2014-01-01

    The observed depletion of the ozone layer from the 1980s onwards is attributed to halogen source gases emitted by human activities. However, the precision of this attribution is complicated by year-to-year variations in meteorology, that is, dynamical variability, and by changes in tropospheric ozone concentrations. As such, key aspects of the total-column ozone record, which combines changes in both tropospheric and stratospheric ozone, remain unexplained, such as the apparent absence of a decline in total-column ozone levels before 1980, and of any long-term decline in total-column ozone levels in the tropics. Here we use a chemistry-climate model to estimate changes in halogen-induced ozone loss between 1960 and 2010; the model is constrained by observed meteorology to remove the eects of dynamical variability, and driven by emissions of tropospheric ozone precursors to separate out changes in tropospheric ozone. We show that halogen-induced ozone loss closely followed stratospheric halogen loading over the studied period. Pronounced enhancements in ozone loss were apparent in both hemispheres following the volcanic eruptions of El Chichon and, in particular, Mount Pinatubo, which significantly enhanced stratospheric aerosol loads. We further show that approximately 40% of the long-term non-volcanic ozone loss occurred before 1980, and that long-term ozone loss also occurred in the tropical stratosphere. Finally, we show that halogeninduced ozone loss has declined by over 10% since stratospheric halogen loading peaked in the late 1990s, indicating that the recovery of the ozone layer is well underway.

  3. Influence of ozone on RNA and protein content of Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Craker, L E

    1972-01-01

    The amount of RNA and protein in Lemna minor L. plants decreased after exposure to ozone, as compared with control plants receiving no ozone treatment. Differences in RNA and protein content between control and ozone-treated Lemna plants were detectable immediately following ozone treatments and remained throughout the 24 h sampling time.

  4. Ozone Layer Protection

    Science.gov (United States)

    ... and Research Centers Contact Us Share Ozone Layer Protection The stratospheric ozone layer is Earth’s “sunscreen” – protecting ... GreenChill Partnership Responsible Appliance Disposal (RAD) Program Ozone Protection vs. Ozone Pollution This website addresses stratospheric ozone ...

  5. Effects of ozone on crops in north-west Pakistan

    International Nuclear Information System (INIS)

    Ahmad, Muhammad Nauman; Büker, Patrick; Khalid, Sofia; Van Den Berg, Leon; Shah, Hamid Ullah; Wahid, Abdul; Emberson, Lisa; Power, Sally A.; Ashmore, Mike

    2013-01-01

    Although ozone is well-documented to reduce crop yields in the densely populated Indo-Gangetic Plain, there is little knowledge of its effects in other parts of south Asia. We surveyed crops close to the city of Peshawar, in north-west Pakistan, for visible injury, linking this to passive measurements of ozone concentrations. Foliar injury was found on potato, onion and cotton when mean monthly ozone concentrations exceeded 45 ppb. The symptoms on onion were reproduced in ozone fumigation experiments, which also showed that daytime ozone concentrations of 60 ppb significantly reduce the growth of a major Pakistani onion variety. Aphid infestation on spinach was also reduced at these elevated ozone concentrations. The ozone concentrations measured in April–May in Peshawar, and used in the fumigation experiment, are comparable to those that have been modelled to occur over many parts of south Asia, where ozone may be a significant threat to sensitive crops. -- Highlights: ► Visible ozone injury to onion, cotton and potato was identified in north-west Pakistan. ► The symptoms on onion were reproduced by exposure to elevated ozone. ► Elevated ozone levels also significantly reduced onion growth. ► Levels of aphid infestation on spinach were lower under elevated ozone. ► These effects were observed at ozone levels that have been modelled to occur widely across south Asia. -- Ozone concentrations in NW Pakistan have adverse effects on sensitive crop species

  6. Assimilation of carbon and transport of assimilates in coniferous trees under the influence of airborne pollutants. Photosynthesis rate and assimilate distribution in young fir trees (Picea abies [L.]Karst.) under controlled exposure to ozone. Final report; Assimilation von Kohlenstoff und der Assimilattransport in Coniferen unter dem Einfluss von Luftschadstoffen. Photosyntheseleistung und Assimilatverteilung in jungen Fichten (Picea abies [L.]Karst.) unter kontrollierter Ozon-Exposition. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Willenbrink, J.; Schatten, T.

    1992-12-31

    In this project, effects of long-term, low-level ozone exposure on CO{sub 2}fixation and assimilate partitioning in 4-years spruces old were studied. 1. In October, ozone exposure resulted in a 40% decrease of photosynthesis. Chlorophyll content was not altered. Depression of net photosynthesis by ozone exposure fluctuates. At least partly, this depression of net photosynthesis might reflect an increase of respiration. After 6 weeks of ozone exposure, both stomatal conductivity and transpiration seemed to be lowered. However, internal [CO{sub 2}] and water use efficiency were not significantly altered. 2. Compared with the control, needles of ozone-exposed plants exhibited a shift of the {sup 14}C-ratio of {beta}-carotene/xanthophylls which effect faded away with the season (October). 3. In August and October, translocation of {sup 14}C-assimilates from the {sup 14}C-fed source leaves seems to be impeded by ozone exposure. 4. No O{sub 3}-related differences were found for the lipophilic as well as for the fractions of organic or amino acids. For the sink tissues (twig, stem, root), less label was found in non-starch residue in August (main growth season), in O{sub 3}-exposed plants. 5. Starch and sugar content of cortex, cambium, xylem, and of the root follow annual cycles. Under ozon exposure, levels of {sup 14}C-starch and {sup 14}C-sucrose are lowered whereas in the needles, build-up of {sup 14}C-starch was detected. 6. Obviously, long-term low-level ozone affects allocation of assimilates. Secondary effects on chloroplasts by the treatment cannot be excluded. (orig./UWA) [Deutsch] Unter Labor- bzw. Gewaechshausbedingungen wurde der Einfluss einer kontrollierten Ozonexposition auf die Photosyntheseleistung und die Assimilatverteilung in 4-jaehrigen Fichten untersucht. 1. Unter Ozon-Exposition wird die Netto-Photosyntheserate in den jungen Nadeln zum Herbst hin reduziert, waehrend der Chlorophyllgehalt unbeeinflusst bleibt. Die Photosyntheserate der jungen Nadeln

  7. The Tropospheric Ozone Assessment Report (TOAR): A community-wide effort to quantify tropospheric ozone in a rapidly changing world

    Science.gov (United States)

    Cooper, O. R.; Schultz, M.; Paoletti, E.; Galbally, I. E.; Naja, M. K.; Tarasick, D. W.; Evans, M. J.; Thompson, A. M.

    2017-12-01

    Tropospheric ozone is a greenhouse gas and pollutant detrimental to human health and crop and ecosystem productivity. Since 1990 a large portion of the anthropogenic emissions that react in the atmosphere to produce ozone has shifted from North America and Europe to Asia. This rapid shift, coupled with limited ozone monitoring in developing nations, left scientists unable to answer the most basic questions: Which regions of the world have the greatest human and plant exposure to ozone pollution? Is ozone continuing to decline in nations with strong emissions controls? To what extent is ozone increasing in the developing world? How can the atmospheric sciences community facilitate access to the ozone metrics necessary for quantifying ozone's impact on human health and crop/ecosystem productivity? To answer these questions the International Global Atmospheric Chemistry Project (IGAC) initiated the Tropospheric Ozone Assessment Report (TOAR). With over 220 member scientists and air quality specialists from 36 nations, TOAR's mission is to provide the research community with an up-to-date scientific assessment of tropospheric ozone's global distribution and trends from the surface to the tropopause. TOAR has also built the world's largest database of surface ozone observations and generated ozone exposure and dose metrics at thousands of measurement sites around the world, freely accessible for research on the global-scale impact of ozone on climate, human health and crop/ecosystem productivity. Plots of these metrics show the regions of the world with the greatest ozone exposure for humans and crops/ecosystems, at least in areas where observations are available. The results also highlight regions where air quality is improving and where it has degraded. TOAR has also conducted the first intercomparison of tropospheric column ozone from ozonesondes and multiple satellite instruments, which provide similar estimates of the present-day tropospheric ozone burden.

  8. Does D-cycloserine enhance exposure therapy for anxiety disorders in humans? A meta-analysis.

    Directory of Open Access Journals (Sweden)

    Helga Rodrigues

    Full Text Available The treatment of anxiety is on the edge of a new era of combinations of pharmacologic and psychosocial interventions. A new wave of translational research has focused on the use of pharmacological agents as psychotherapy adjuvants using neurobiological insights into the mechanism of the action of certain psychological treatments such as exposure therapy. Recently, d-cycloserine (DCS an antibiotic used to treat tuberculosis has been applied to enhance exposure-based treatment for anxiety and has proved to be a promising, but as yet unproven intervention. The present study aimed to evaluate the efficacy of DCS in the enhancement of exposure therapy in anxiety disorders. A systematic review/meta-analysis was conducted. Electronic searches were conducted in the databases ISI-Web of Science, Pubmed and PsycINFO. We included only randomized, double-blind, placebo-controlled trials with humans, focusing on the role of DCS in enhancing the action of exposure therapy for anxiety disorders. We identified 328 references, 13 studies were included in our final sample: 4 on obsessive-compulsive disorder, 2 on panic disorder, 2 on social anxiety disorder, 2 on posttraumatic stress disorder, one on acrophobia, and 2 on snake phobia. The results of the present meta-analysis show that DCS enhances exposure therapy in the treatment of anxiety disorders (Cohen d =  -0.34; CI: -0.54 to -0.14, facilitating the specific process of extinction of fear. DCS seems to be effective when administered at a time close to the exposure therapy, at low doses and a limited number of times. DCS emerges as a potential new therapeutic approach for patients with refractory anxiety disorders that are unresponsive to the conventional treatments available. When administered correctly, DCS is a promising strategy for augmentation of CBT and could reduce health care costs, drop-out rates and bring faster relief to patients.

  9. Chronic subhepatotoxic exposure to arsenic enhances hepatic injury caused by high fat diet in mice

    International Nuclear Information System (INIS)

    Tan, Min; Schmidt, Robin H.; Beier, Juliane I.; Watson, Walter H.; Zhong, Hai; States, J. Christopher; Arteel, Gavin E.

    2011-01-01

    Arsenic is a ubiquitous contaminant in drinking water. Whereas arsenic can be directly hepatotoxic, the concentrations/doses required are generally higher than present in the US water supply. However, physiological/biochemical changes that are alone pathologically inert can enhance the hepatotoxic response to a subsequent stimulus. Such a ‘2-hit’ paradigm is best exemplified in chronic fatty liver diseases. Here, the hypothesis that low arsenic exposure sensitizes liver to hepatotoxicity in a mouse model of non-alcoholic fatty liver disease was tested. Accordingly, male C57Bl/6J mice were exposed to low fat diet (LFD; 13% calories as fat) or high fat diet (HFD; 42% calories as fat) and tap water or arsenic (4.9 ppm as sodium arsenite) for ten weeks. Biochemical and histologic indices of liver damage were determined. High fat diet (± arsenic) significantly increased body weight gain in mice compared with low-fat controls. HFD significantly increased liver to body weight ratios; this variable was unaffected by arsenic exposure. HFD caused steatohepatitis, as indicated by histological assessment and by increases in plasma ALT and AST. Although arsenic exposure had no effect on indices of liver damage in LFD-fed animals, it significantly increased the liver damage caused by HFD. This effect of arsenic correlated with enhanced inflammation and fibrin extracellular matrix (ECM) deposition. These data indicate that subhepatotoxic arsenic exposure enhances the toxicity of HFD. These results also suggest that arsenic exposure might be a risk factor for the development of fatty liver disease in human populations. -- Highlights: ► Characterizes a mouse model of arsenic enhanced NAFLD. ► Arsenic synergistically enhances experimental fatty liver disease at concentrations that cause no overt hepatotoxicity alone. ► This effect is associated with increased inflammation.

  10. Elodea nuttallii exposure to mercury exposure under enhanced ultraviolet radiation: Effects on bioaccumulation, transcriptome, pigment content and oxidative stress.

    Science.gov (United States)

    Regier, Nicole; Beauvais-Flück, Rebecca; Slaveykova, Vera I; Cosio, Claudia

    2016-11-01

    The hypothesis that increased UV radiation result in co-tolerance to Hg toxicity in aquatic plants was studied at the physiological and transcriptomic level in Elodea nuttallii. At the transcriptomic level, combined exposure to UV+Hg enhanced the stress response in comparison with single treatments, affecting the expression level of transcripts involved in energy metabolism, lipid metabolism, nutrition, and redox homeostasis. Single and combined UV and Hg treatments dysregulated different genes but with similar functions, suggesting a fine regulation of the plant to stresses triggered by Hg, UV and their combination but lack of co-tolerance. At the physiological level, UV+Hg treatment reduced chlorophyll content and depleted antioxidative compounds such as anthocyanin and GSH/GSSG in E. nuttallii. Nonetheless, combined exposure to UV+Hg resulted in about 30% reduction of Hg accumulation into shoots vs exposure to Hg alone, which was congruent with the level of expression of several transporter genes, as well as the UV effect on Hg bioavailability in water. The findings of the present work underlined the importance of performing experimentation under environmentally realistic conditions and to consider the interplay between contaminants and environmental variables such as light that might have confounding effects to better understand and anticipate the effects of multiple stressors in aquatic environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. How closely does stem growth of adult beech (Fagus sylvatica) relate to net carbon gain under experimentally enhanced ozone stress?

    International Nuclear Information System (INIS)

    Kitao, Mitsutoshi; Winkler, J. Barbro; Löw, Markus; Nunn, Angela J.; Kuptz, Daniel; Häberle, Karl-Heinz; Reiter, Ilja M.; Matyssek, Rainer

    2012-01-01

    The hypothesis was tested that O 3 -induced changes in leaf-level photosynthetic parameters have the capacity of limiting the seasonal photosynthetic carbon gain of adult beech trees. To this end, canopy-level photosynthetic carbon gain and respiratory carbon loss were assessed in European beech (Fagus sylvatica) by using a physiologically based model, integrating environmental and photosynthetic parameters. The latter were derived from leaves at various canopy positions under the ambient O 3 regime, as prevailing at the forest site (control), or under an experimental twice-ambient O 3 regime (elevated O 3 ), as released through a free-air canopy O 3 fumigation system. Gross carbon gain at the canopy-level declined by 1.7%, while respiratory carbon loss increased by 4.6% under elevated O 3 . As this outcome only partly accounts for the decline in stem growth, O 3 -induced changes in allocation are referred to and discussed as crucial in quantitatively linking carbon gain with stem growth. - Highlights: ► We model O 3 -induced changes in the photosynthetic carbon gain of adult beech trees. ► Elevated O 3 decreases gross carbon gain but increases respiratory carbon loss. ► Reduction in net carbon gain only partly accounts for the decline in stem growth. ► O 3 effects on the whole-tree allocation is crucial in addition to carbon gains. - Reduction in net carbon gain at the canopy level only partly accounts for the decline in stem growth under elevated ozone.

  12. Enhanced treatment of secondary municipal wastewater effluent: comparing (biological) filtration and ozonation in view of micropollutant removal, unselective effluent toxicity, and the potential for real-time control.

    Science.gov (United States)

    Chys, Michael; Demeestere, Kristof; Ingabire, Ange Sabine; Dries, Jan; Van Langenhove, Herman; Van Hulle, Stijn W H

    2017-07-01

    Ozonation and three (biological) filtration techniques (trickling filtration (TF), slow sand filtration (SSF) and biological activated carbon (BAC) filtration) have been evaluated in different combinations as tertiary treatment for municipal wastewater effluent. The removal of 18 multi-class pharmaceuticals, as model trace organic contaminants (TrOCs), has been studied. (Biological) activated carbon filtration could reduce the amount of TrOCs significantly (>99%) but is cost-intensive for full-scale applications. Filtration techniques mainly depending on biodegradation mechanisms (TF and SSF) are found to be inefficient for TrOCs removal as a stand alone technique. Ozonation resulted in 90% removal of the total amount of quantified TrOCs, but a post-ozonation step is needed to cope with an increased unselective toxicity. SSF following ozonation showed to be the only technique able to reduce the unselective toxicity to the same level as before ozonation. In view of process control, innovative correlation models developed for the monitoring and control of TrOC removal during ozonation, are verified for their applicability during ozonation in combination with TF, SSF or BAC. Particularly for the poorly ozone reactive TrOCs, statistically significant models were obtained that correlate TrOC removal and reduction in UVA 254 as an online measured surrogate parameter.

  13. Effects of mineral nutrients on ozone susceptibility of Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Craker, L E

    1971-01-01

    Susceptibility of Lemna minor L. to ozone injury was influenced by the mineral nutrients available to the Lemna plants. Additional nitrogen or additional iron in the nutrient media respectively enhanced or reduced chlorophyll loss of Lemna plants fumigated with ozone. Lemna plants growing on a nutrient medium lacking copper had significantly less injury from ozone fumigation than Lemna plants growing on a complete nutrient medium. There were apparent interactions among phosphorus and potassium nutrient levels in determing the Lemna plant's susceptibility to ozone.

  14. Interaction of ozone with plastic and metallic materials in a dynamic flow system

    Energy Technology Data Exchange (ETDEWEB)

    Altshuller, A P; Wartburg, A F

    1961-01-01

    The loss of ozone in the p.p.h.m. range after passing through or over various plastic and metallic substances has been investigated. The materials used include Teflon, glass, stainless steel, aluminium, polyethylene and polyvinyl tubing, Mylar film, and aluminium foil. Unused Teflon passes ozone without loss. Glass tubing, after a short exposure to ozone, passes ozone without loss. Stainless steel tubing, aluminum tubing or foil and Mylar film must be exposed to ozone in the p.p.h.m. range for several hours before 90% or more of the ozone initially present can be passed through or over these materials. More rapid conditioning to ozone can be achieved by several five to fifteen-minute exposures to about 10 p.p.m. of ozone. Polyethylene and Nalgon tubing even after many hours of exposure to ozone will pass only 75 to 80% of the ozone initially present in the gas stream. Some types of polyvinyl tubing are unsatisfactory for use with ozone irrespective of the amount of exposure to ozone. Flowrates below 1000 c/sup 3//min. will increase losses of ozone. Except for Teflon and glass, materials should not be used in ozone analysis under any circumstances at low flowrates until they are thoroughly conditioned. Results obtained with stainless steel, aluminium and polyethylene indicate that conditioning to ozone once obtained will persist for at least two weeks.

  15. Species- and age-dependent sensitivity to ozone in young plants of pea, wheat and spinach. Effects on acyl lipid and pigment content and metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, A.S.; Wallin, G.; Sandelius, A.S.

    1996-11-01

    Acyl lipids and pigments were analyzed in young plants of garden pea, spring wheat and spinach exposed to < 5 or 65 nl l{sup -1} ozone 12 h per day for 5 days, in one set of experiments, the plants were exposed to {sup 14}CO{sub 2} for 2 h 3 days prior to ozone exposure. The plants responded differently to the moderately enhanced level of ozone used. Spinach was not at all sensitive while in both pea and wheat, leaves of different ages differed in ozone sensitivity. In pea, ozone sensitivity increased with leaf age. In the second and third oldest leaves, the amounts of galactolipids per leaf area and the proportions of 18:3 of the total lipid extract and of phosphatidylglycerol decreased. In the second oldest leaf, ozone also caused a decreased proportion of 18:3 of monogalactosyldiacylglycerol. In the fourth oldest leaf, lipid composition and galactolipid unsaturation was unaffected, but ozone caused decreased leaf expansion resulting in increased acyl lipid content per leaf area. In both the first and second leaves of wheat, ozone fumigation caused a marked decrease in the content of monogalactosyldiacylglycerol and in the first leaf, the contents of phosphatidylcholine and phosphatidylethanolamine increased. The proportion of 18:3 in phosphatidylcholine was larger in ozone-fumigated than in control plants, while the reverse applied for phosphatidylglycerol. In the oldest sampled leaves of pea and wheat, ozone caused an increase in the radioactivity associated with {beta}-carotene, indicting increased turnover. Thus, while spinach was unaffected, in both pea and whet ozone caused a decrease in the proportion of chloroplast membrane lipids to non-chloroplast membrane lipids in older leaves while younger leaves were less sensitive. (au) 21 refs.

  16. Ozone killing action against bacterial and fungal species; microbiological testing of a domestic ozone generator.

    Science.gov (United States)

    Dyas, A; Boughton, B J; Das, B C

    1983-10-01

    The action of ozone generated from a small domestic device was examined with a view to using it in clinical isolation units accommodating immunosuppressed patients. Over a six-hour period in an average size room the device did not generate sufficient ozone to suppress bacterial and fungal growth. A useful bactericidal action, against a variety of human pathogens was achieved with ozone concentrations between 0.3 to 0.9 ppm. Bactericidal ozone concentrations are close to the limit permitted for human exposure however and further experiments are indicated.

  17. Elodea nuttallii exposure to mercury exposure under enhanced ultraviolet radiation: Effects on bioaccumulation, transcriptome, pigment content and oxidative stress

    International Nuclear Information System (INIS)

    Regier, Nicole; Beauvais-Flück, Rebecca; Slaveykova, Vera I.; Cosio, Claudia

    2016-01-01

    Highlights: • Exposure to UV radiation does not result in co-tolerance to Hg in Elodea nuttallii. • UV radiation increased the stress response to Hg at the transcriptome level. • UV + Hg dysregulated genes of energy and lipid metabolism, nutrition and redox homeostasis. • UV + Hg treatment decreases Hg accumulation in E. nuttallii shoots. • Hg accumulation depends on UV effects on plant metabolism and Hg bioavailability. - Abstract: The hypothesis that increased UV radiation result in co-tolerance to Hg toxicity in aquatic plants was studied at the physiological and transcriptomic level in Elodea nuttallii. At the transcriptomic level, combined exposure to UV + Hg enhanced the stress response in comparison with single treatments, affecting the expression level of transcripts involved in energy metabolism, lipid metabolism, nutrition, and redox homeostasis. Single and combined UV and Hg treatments dysregulated different genes but with similar functions, suggesting a fine regulation of the plant to stresses triggered by Hg, UV and their combination but lack of co-tolerance. At the physiological level, UV + Hg treatment reduced chlorophyll content and depleted antioxidative compounds such as anthocyanin and GSH/GSSG in E. nuttallii. Nonetheless, combined exposure to UV + Hg resulted in about 30% reduction of Hg accumulation into shoots vs exposure to Hg alone, which was congruent with the level of expression of several transporter genes, as well as the UV effect on Hg bioavailability in water. The findings of the present work underlined the importance of performing experimentation under environmentally realistic conditions and to consider the interplay between contaminants and environmental variables such as light that might have confounding effects to better understand and anticipate the effects of multiple stressors in aquatic environment.

  18. Elodea nuttallii exposure to mercury exposure under enhanced ultraviolet radiation: Effects on bioaccumulation, transcriptome, pigment content and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Regier, Nicole; Beauvais-Flück, Rebecca; Slaveykova, Vera I.; Cosio, Claudia, E-mail: Claudia.Cosio@unige.ch

    2016-11-15

    Highlights: • Exposure to UV radiation does not result in co-tolerance to Hg in Elodea nuttallii. • UV radiation increased the stress response to Hg at the transcriptome level. • UV + Hg dysregulated genes of energy and lipid metabolism, nutrition and redox homeostasis. • UV + Hg treatment decreases Hg accumulation in E. nuttallii shoots. • Hg accumulation depends on UV effects on plant metabolism and Hg bioavailability. - Abstract: The hypothesis that increased UV radiation result in co-tolerance to Hg toxicity in aquatic plants was studied at the physiological and transcriptomic level in Elodea nuttallii. At the transcriptomic level, combined exposure to UV + Hg enhanced the stress response in comparison with single treatments, affecting the expression level of transcripts involved in energy metabolism, lipid metabolism, nutrition, and redox homeostasis. Single and combined UV and Hg treatments dysregulated different genes but with similar functions, suggesting a fine regulation of the plant to stresses triggered by Hg, UV and their combination but lack of co-tolerance. At the physiological level, UV + Hg treatment reduced chlorophyll content and depleted antioxidative compounds such as anthocyanin and GSH/GSSG in E. nuttallii. Nonetheless, combined exposure to UV + Hg resulted in about 30% reduction of Hg accumulation into shoots vs exposure to Hg alone, which was congruent with the level of expression of several transporter genes, as well as the UV effect on Hg bioavailability in water. The findings of the present work underlined the importance of performing experimentation under environmentally realistic conditions and to consider the interplay between contaminants and environmental variables such as light that might have confounding effects to better understand and anticipate the effects of multiple stressors in aquatic environment.

  19. Autophagy deficiency in macrophages enhances NLRP3 inflammasome activity and chronic lung disease following silica exposure

    International Nuclear Information System (INIS)

    Jessop, Forrest; Hamilton, Raymond F.; Rhoderick, Joseph F.; Shaw, Pamela K.; Holian, Andrij

    2016-01-01

    Autophagy is an important metabolic mechanism that can promote cellular survival following injury. The specific contribution of autophagy to silica-induced inflammation and disease is not known. The objective of these studies was to determine the effects of silica exposure on the autophagic pathway in macrophages, as well as the general contribution of autophagy in macrophages to inflammation and disease. Silica exposure enhanced autophagic activity in vitro in Bone Marrow derived Macrophages and in vivo in Alveolar Macrophages isolated from silica-exposed mice. Impairment of autophagy in myeloid cells in vivo using Atg5 fl/fl LysM-Cre + mice resulted in enhanced cytotoxicity and inflammation after silica exposure compared to littermate controls, including elevated IL-18 and the alarmin HMGB1 in the whole lavage fluid. Autophagy deficiency caused some spontaneous inflammation and disease. Greater silica-induced acute inflammation in Atg5 fl/fl LysM-Cre + mice correlated with increased fibrosis and chronic lung disease. These studies demonstrate a critical role for autophagy in suppressing silica-induced cytotoxicity and inflammation in disease development. Furthermore, this data highlights the importance of basal autophagy in macrophages and other myeloid cells in maintaining lung homeostasis. - Highlights: • Silica exposure increases autophagy in macrophages. • Autophagy deficient mice have enhanced inflammation and silicosis. • Autophagy deficiency in macrophages results in greater silica-induced cytotoxicity. • Autophagy deficiency in macrophages increases extracellular IL-18 and HMGB1.

  20. Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst)

    International Nuclear Information System (INIS)

    Nikolova, Petia S.; Andersen, Christian P.; Blaschke, Helmut; Matyssek, Rainer; Haeberle, Karl-Heinz

    2010-01-01

    The effects of experimentally elevated O 3 on soil respiration rates, standing fine-root biomass, fine-root production and δ 13 C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O 3 under beech and spruce, and was related to O 3 -stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O 3 on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O 3 regime. δ 13 C signature of newly formed fine-roots was consistent with the differing g s of beech and spruce, and indicated stomatal limitation by O 3 in beech and by drought in spruce. Our study showed that drought can override the stimulating O 3 effects on fine-root dynamics and soil respiration in mature beech and spruce forests. - Drought has the capacity to override the stimulating ozone effect on soil respiration in adult European beech/Norway spruce forest.

  1. High Fructose/High Fat Diets Mediate Changes in Protein Carbonyl Content in the Rat Brain With and Without Ozone Exposure

    Science.gov (United States)

    The consumption of diets rich in fat or fructose have been correlated to a rise in type-2 diabetes and obesity. These diet-induced physiological changes have been shown previously to cause an increase in responsiveness to air pollutants such as ozone (03). 03 is a pervasive air p...

  2. Effects of ozone chemistry and outside air supply on passenger self-evalua-tion of symptoms during 4-hour exposures in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Tamás, Gyöngyi; Myśków, Danuta

    2006-01-01

    Experiments were carried out in a simulated 21-seat section of an aircraft cabin, installed in a climate chamber, to determine the extent to which cabin air quality and passenger symptoms are affected by ozone chemistry. A total of 30 subjects were exposed to four conditions: two rates of outside...

  3. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    NARCIS (Netherlands)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, T.A.

    2004-01-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris.

  4. Effects of ozone-vegetation coupling on surface ozone air quality via biogeochemical and meteorological feedbacks

    Science.gov (United States)

    Sadiq, Mehliyar; Tai, Amos P. K.; Lombardozzi, Danica; Martin, Maria Val

    2017-02-01

    Tropospheric ozone is one of the most hazardous air pollutants as it harms both human health and plant productivity. Foliage uptake of ozone via dry deposition damages photosynthesis and causes stomatal closure. These foliage changes could lead to a cascade of biogeochemical and biogeophysical effects that not only modulate the carbon cycle, regional hydrometeorology and climate, but also cause feedbacks onto surface ozone concentration itself. In this study, we implement a semi-empirical parameterization of ozone damage on vegetation in the Community Earth System Model to enable online ozone-vegetation coupling, so that for the first time ecosystem structure and ozone concentration can coevolve in fully coupled land-atmosphere simulations. With ozone-vegetation coupling, present-day surface ozone is simulated to be higher by up to 4-6 ppbv over Europe, North America and China. Reduced dry deposition velocity following ozone damage contributes to ˜ 40-100 % of those increases, constituting a significant positive biogeochemical feedback on ozone air quality. Enhanced biogenic isoprene emission is found to contribute to most of the remaining increases, and is driven mainly by higher vegetation temperature that results from lower transpiration rate. This isoprene-driven pathway represents an indirect, positive meteorological feedback. The reduction in both dry deposition and transpiration is mostly associated with reduced stomatal conductance following ozone damage, whereas the modification of photosynthesis and further changes in ecosystem productivity are found to play a smaller role in contributing to the ozone-vegetation feedbacks. Our results highlight the need to consider two-way ozone-vegetation coupling in Earth system models to derive a more complete understanding and yield more reliable future predictions of ozone air quality.

  5. Enhanced eyeblink conditioning in behaviorally inhibited individuals is disrupted by proactive interference following US alone pre-exposures.

    Directory of Open Access Journals (Sweden)

    Michael Todd Allen

    2016-03-01

    Full Text Available Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from CS or US alone pre-exposures (Holloway et al., 2012. US alone pre-exposures disrupt subsequent CR acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al., (2012 reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioural Inhibition (AMBI. Sixty six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI individuals exhibited enhanced proactive interference as compared to non-inhibited (NI individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible learned helplessness. Applications of these findings of

  6. Radiation exposure of contrast-enhanced spectral mammography compared with full-field digital mammography.

    Science.gov (United States)

    Jeukens, Cécile R L P N; Lalji, Ulrich C; Meijer, Eduard; Bakija, Betina; Theunissen, Robin; Wildberger, Joachim E; Lobbes, Marc B I

    2014-10-01

    Contrast-enhanced spectral mammography (CESM) shows promising initial results but comes at the cost of increased dose as compared with full-field digital mammography (FFDM). We aimed to quantitatively assess the dose increase of CESM in comparison with FFDM. Radiation exposure-related data (such as kilovoltage, compressed breast thickness, glandularity, entrance skin air kerma (ESAK), and average glandular dose (AGD) were retrieved for 47 CESM and 715 FFDM patients. All examinations were performed on 1 mammography unit. Radiation dose values reported by the unit were validated by phantom measurements. Descriptive statistics of the patient data were generated using a statistical software package. Dose values reported by the mammography unit were in good qualitative agreement with those of phantom measurements. Mean ESAK was 10.5 mGy for a CESM exposure and 7.46 mGy for an FFDM exposure. Mean AGD for a CESM exposure was 2.80 mGy and 1.55 mGy for an FFDM exposure. Compared with our institutional FFDM, the AGD of a single CESM exposure is increased by 1.25 mGy (+81%), whereas ESAK is increased by 3.07 mGy (+41%). Dose values of both techniques meet the recommendations for maximum dose in mammography.

  7. Protective effect of Mn(III)-desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max "Sambaiba".

    Science.gov (United States)

    Esposito, Jéssica Bordotti Nobre; Esposito, Breno Pannia; Azevedo, Ricardo Antunes; Cruz, Luciano Soares; da Silva, Luzimar Campos; de Souza, Silvia Ribeiro

    2015-04-01

    This study aimed to investigate the effects of the Mn complex (Mn(III)-desferrioxamine B (MnDFB)) on oxidative stress in the Brazilian soybean cultivar Glycine max "Sambaiba" following exposure to ozone and acid rain. We determined the suitable dose of MnDFB to apply to G. max seedlings using a dose-response curve. The highest superoxide dismutase (SOD) activity and Mn content in leaves were found upon the application of 8 μM MnDFB. Thus, G. max seedlings pretreated with 8 μM MnDFB were individually exposed to ozone and acid rain simulated. Pretreatment with MnDFB reduced lipid peroxidation upon ozone exposure and increased SOD activity in leaves; it did not alter the metal content in any part of the plant. Conversely, following acid rain exposure, neither the metal content in leaves nor SOD enzyme activity were directly affected by MnDFB, unlike pH. Our findings demonstrated that exogenous MnDFB application before ozone exposure may modulate the MnSOD, Cu/ZnSOD, and FeSOD activities to combat the ROS excess in the cell. Here, we demonstrated that the applied dose of MnDFB enhances antioxidative defenses in soybean following exposure to acid rain and especially to ozone.

  8. Influence of enhanced Asian NOx emissions on ozone in the upper troposphere and lower stratosphere in chemistry–climate model simulations

    Directory of Open Access Journals (Sweden)

    C. Roy

    2017-01-01

    78.5 mW m−2 respectively. These elevated NOx emissions produce significant warming over the Tibetan Plateau and increase precipitation over India due to a strengthening of the monsoon Hadley circulation. However, increase in NOx emissions over India by 73 % (similar to the observed increase over China results in large ozone production over the Indo-Gangetic Plain and Tibetan Plateau. The higher ozone concentrations, in turn, induce a reversed monsoon Hadley circulation and negative precipitation anomalies over India. The associated subsidence suppresses vertical transport of NOx and ozone into the ASM anticyclone.

  9. Two-phase ozonation of chlorinated organics

    International Nuclear Information System (INIS)

    Bhattacharyya, D.; Freshour, A.; West, D.

    1995-01-01

    In the last few years the amount of research being conducted in the field of single-phase ozonation has grown extensively. However, traditional aqueous-phase ozonation systems are limited by a lack of selective oxidation potential, low ozone solubility in water, and slow intermediate decomposition rates. Furthermore, ozone may decompose before it can be utilized for pollutant destruction since ozone can be highly unstable in aqueous solutions. Naturally occurring compounds such as NaHCO 3 also affect ozone reactions by inhibiting the formation of OH-free radicals. To compensate for these factors, excess ozone is typically supplied to a reactor. Since ozone generation requires considerable electric power consumption (16 - 24 kWh/kg of O 3 ), attempts to enhance the ozone utilization rate and stability should lead to more efficient application of this process to hazardous waste treatment. To improve the process, ozonation may be more efficiently carried out in a two-phase system consisting of an inert solvent (saturated with O 3 ) contacted with an aqueous phase containing pollutants. The non-aqueous phase must meet the following criteria: (1) non-toxic, (2) very low vapor pressure, (3) high density (for ease of separation), (4) complete insolubility in water, (5) reusability, (6) selective pollutant extractability, (7) high oxidant solubility, and (8) extended O 3 stability. Previously published studies (1) have indicated that a number of fluorinated hydrocarbon compounds fit these criteria. For this project, FC40 (a product of 3M Co.) was chosen due to its low vapor pressure (3 mm Hg) and high specific gravity (1.9). The primary advantages of the FC40 solvent are that it is non-toxic, reusable, has an ozone solubility 10 times that of water, and that 85 % of the ozone remains in the solvent even after 2 hours. This novel two-phase process has been utilized to study the rapid destruction of organic chlorine compounds and organic mixtures

  10. Plant Signals Disrupt (regulate?) Arbuscular Mycorrhizal Fungal Growth Under Enhanced Ozone and CO2 Growing Conditions for Populus tremuloides

    Science.gov (United States)

    Miller, R. M.; Podila, G. K.

    2008-12-01

    An understanding of the genetic determinants of keystone symbiotic relationships is essential to elucidating adaptive mechanisms influencing higher-order processes, including shifts in community composition following environmental perturbations. The Aspen FACE project offers a unique opportunity to address adaptive processes with an imposed three way interaction experiment composed of the atmospheric pollutant ozone (eO3), elevated CO2 (eCO2) fumigations, five Populus tremuloides (aspen) genotypes, and both arbuscular mycorrhizal and ectomycorrhizal fungal interactions. The 10 year time span of this experiment has allowed for a realistic and mechanistic understanding of above ground responses of the aspen genotypes to eCO2, eO3 and the interaction effects of eCO2 and eO3. Even so, treatment influences to the below ground, including carbon allocation to roots and associated mycorrhizal symbionts, and rhizosphere dynamics are just beginning to be understood. We hypothesized that mycorrhizal fungal responses to eCO2, eO3, and the interaction effects of eCO2+eO3 are conditioned by the degree of response of their aspen hosts. We intend to describe the molecular mechanisms of an important critical interaction between host and fungus using microarray analysis of expression profiles, as well as metabolic profiling of aspen roots and their associated mycorrhizal partner, the arbuscular mycorrhizal fungus (AMF) Glomus intraradices, under eCO2, eO3 and eCO2+eO3. We present evidence that host-derived factors, expressed in response to eCO2+eO3, trigger responses in Glomus leading to the partitioning or metabolic shift in lipid biosynthesis that is associated with reduced extraradical hyphae growth and altered lipid metabolism. We then scale these lower-level responses to give better insight to fungal intraradical and extraradical allocation of biomass and fungal and root lipid and carbohydrate content in association with aspen genotype responses to the imposed treatments. By

  11. Ozone acts alone and synergistically with ionizing radiation to induce in vitro neoplastic transformation

    Energy Technology Data Exchange (ETDEWEB)

    Borek, C; Zaider, M; Ong, A; Mason, H; Witz, G

    1986-09-01

    Ozone, a major chemical oxidant in the atmosphere, is an environmental air pollutant whose ability to act as a direct carcinogen is unclear. Using in vitro transformation, a technique which permits the study of oncogenesis in the absence of host specific effects, it is reported for the first time that ozone (5 p.p.m. for 5 min) induces neoplastic transformation in vitro in both primary hamster embryo cells and mouse fibroblast cultures (C3H/10-1/2). Exposure of the hamster and mouse cells to ozone also results in enhanced levels of free radical-mediated lipid peroxidation products. The carcinogenic interaction between ozone and ionizing radiation is also reported. Exposure of the cells to 3 or 4 Gy of ..gamma..-rays, 2 h prior to O/sub 3/ treatment, results in markedly enhanced rates of transformation, statistically consistent with a synergistic interaction between the agents. The results demonstrate that O/sub 3/ acts as a direct carcinogen and co-carcinogen on susceptible cells, therefore having important consequences for public health.

  12. Perinatal Exposure to Environmental Tobacco Smoke (ETS Enhances Susceptibility to Viral and Secondary Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Jocelyn A. Claude

    2012-10-01

    Full Text Available Studies suggest childhood exposure to environmental tobacco smoke (ETS leads to increased incidence of infections of the lower respiratory tract. The objective of this study was to determine whether perinatal exposure to ETS increases the incidence, morbidity and severity of respiratory influenza infection and whether a secondary bacterial challenge at the peak of a pre-existing viral infection creates an enhanced host-pathogen susceptibility to an opportunistic infection. Timed-pregnant female Balb/c mice were exposed to either ETS for 6 h/day, 7 d/week beginning on gestation day 14 and continuing with the neonates to 6 weeks of age. Control animals were exposed to filtered air (FA. At the end of exposure, mice were intranasally inoculated with a murine-adapted influenza A. One week later, an intranasal inoculation of S. aureus bacteria was administered. The respective treatment groups were: bacteria only, virus only or virus+bacteria for both FA and ETS-exposed animals for a total of six treatment groups. Animal behavior and body weights were documented daily following infection. Mice were necropsied 1-day post-bacterial infection. Bronchoalveolar lavage fluid (BALF cell analysis demonstrated perinatal exposure to ETS, compared to FA, leads to delayed but enhanced clinical symptoms and enhanced total cell influx into the lungs associated with viral infection followed by bacterial challenge. Viral infection significantly increases the number of neutrophils entering the lungs following bacterial challenge with either FA or ETS exposure, while the influx of lymphocytes and monocytes is significantly enhanced only by perinatal ETS exposure. There is a significant increase in peribronchiolar inflammation following viral infection in pups exposed to ETS compared with pups exposed to FA, but no change is noted in the degree of lung injury between FA and ETS-exposed animals following bacterial challenge. The data suggests perinatal exposure to ETS

  13. Enhanced UV-B radiation alleviates the adverse effects of summer drought in two Mediterranean pines under field conditions [ozone depletion

    International Nuclear Information System (INIS)

    Petropoulou, Y.; Kyparissis, A.; Nikolopoulos, D.; Manetas, Y.

    1995-01-01

    The effects of enhanced UV-B (290-320 nm) radiation on two native Mediterranean pines (Pinus pinea L., Pinus halepensis Mill.) were recorded during a one-year field study. Plants received ambient or ambient plus supplemental UV-B radiation (simulating a 15% stratospheric ozone depletion over Patras. Greece, 38.3°N. 29.1°E) and only natural precipitation, i.e. they were simultaneously exposed to other natural stresses. particularly water stress during summer. Supplemental UV-B irradiation started in early February, 1993 and up to late June, no effects were observed on growth and photochemical efficiency of photosystem II, as measured by chlorophy II fluorescence induction. Water stress during the summer was manifested in the control plants as a decline in the ratio of variable to maximum fluorescence (F v /F m ), the apparent photon yield for oxygen evolution (φ I ) and the photosynthetic capacity at 5% CO 2 (P m ). In addition, a partial needle loss was evident. Under supplemental UV-B radiation, however, the decreases in F v /F m , φ i , and P m . as well as needle losses were significantly less. Soon after the first heavy autumn rains. photosynthetic parameters in both control and UV-B treated plants recovered to similar values. but the transient summer superiority of UV-B irradiated plants resulted in a significant increase in their dry weight measured at plant harvest. during late January. 1994. Plant height. UV-B absorbing compounds, photosynthetic pigments and relative water content measured at late spring. late summer and at plant harvest, were not significantly affected by supplemental UV-B radiation. The results indicate that enhanced UV-B radiation may be beneficial for Mediterranean pines through a partial alleviation of the adverse effects of summer drought. (author)

  14. Enhancing consumer liking of low salt tomato soup over repeated exposure by herb and spice seasonings.

    Science.gov (United States)

    Ghawi, Sameer Khalil; Rowland, Ian; Methven, Lisa

    2014-10-01

    There is strong evidence for the link between high dietary sodium and increased risk of cardiovascular disease which drives the need to reduce salt content in foods. In this study, herb and spice blends were used to enhance consumer acceptability of a low salt tomato soup (0.26% w/w). Subjects (n = 148) scored their liking of tomato soup samples over 5 consecutive days. The first and last days were pre-and post-exposure visits where all participants rated three tomato soup samples; standard, low salt and low salt with added herbs and spices. The middle 3 days were the repeated exposure phase where participants were divided into three balanced groups; consuming the standard soup, the low salt soup, or the low salt soup with added herbs and spices. Reducing salt in the tomato soup led to a significant decline in consumer acceptability, and incorporating herbs and spices did not lead to an immediate enhancement in liking. However, inclusion of herbs and spices enhanced the perception of the salty taste of the low salt soup to the same level as the standard. Repeated exposure to the herbs and spice-modified soup led to a significant increase in the overall liking and liking of flavour, texture and aftertaste of the soup, whereas no changes in liking were observed for the standard and low salt tomato soups over repeated exposure. Moreover, a positive trend in increasing the post-exposure liking of the herbs and spices soup was observed. The findings suggest that the use of herbs and spices is a useful approach to reduce salt content in foods; however, herbs and spices should be chosen carefully to complement the food as large contrasts in flavour can polarise consumer liking. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Cationic peptide exposure enhances pulsed-electric-field-mediated membrane disruption.

    Science.gov (United States)

    Kennedy, Stephen M; Aiken, Erik J; Beres, Kaytlyn A; Hahn, Adam R; Kamin, Samantha J; Hagness, Susan C; Booske, John H; Murphy, William L

    2014-01-01

    The use of pulsed electric fields (PEFs) to irreversibly electroporate cells is a promising approach for destroying undesirable cells. This approach may gain enhanced applicability if the intensity of the PEF required to electrically disrupt cell membranes can be reduced via exposure to a molecular deliverable. This will be particularly impactful if that reduced PEF minimally influences cells that are not exposed to the deliverable. We hypothesized that the introduction of charged molecules to the cell surfaces would create regions of enhanced transmembrane electric potential in the vicinity of each charged molecule, thereby lowering the PEF intensity required to disrupt the plasma membranes. This study will therefore examine if exposure to cationic peptides can enhance a PEF's ability to disrupt plasma membranes. We exposed leukemia cells to 40 μs PEFs in media containing varying concentrations of a cationic peptide, polyarginine. We observed the internalization of a membrane integrity indicator, propidium iodide (PI), in real time. Based on an individual cell's PI fluorescence versus time signature, we were able to determine the relative degree of membrane disruption. When using 1-2 kV/cm, exposure to >50 μg/ml of polyarginine resulted in immediate and high levels of PI uptake, indicating severe membrane disruption, whereas in the absence of peptide, cells predominantly exhibited signatures indicative of no membrane disruption. Additionally, PI entered cells through the anode-facing membrane when exposed to cationic peptide, which was theoretically expected. Exposure to cationic peptides reduced the PEF intensity required to induce rapid and irreversible membrane disruption. Critically, peptide exposure reduced the PEF intensities required to elicit irreversible membrane disruption at normally sub-electroporation intensities. We believe that these cationic peptides, when coupled with current advancements in cell targeting techniques will be useful tools in

  16. Issues in Stratospheric Ozone Depletion.

    Science.gov (United States)

    Lloyd, Steven Andrew

    Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

  17. Secondary maxima in ozone profiles

    Directory of Open Access Journals (Sweden)

    R. Lemoine

    2004-01-01

    Full Text Available Ozone profiles from balloon soundings as well as SAGEII ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is connected to ozone variability and trend at Uccle and account for a large part of the total ozone and lower stratospheric ozone variability.

  18. Subchronic JP-8 jet fuel exposure enhances vulnerability to noise-induced hearing loss in rats.

    Science.gov (United States)

    Fechter, L D; Fisher, J W; Chapman, G D; Mokashi, V P; Ortiz, P A; Reboulet, J E; Stubbs, J E; Lear, A M; McInturf, S M; Prues, S L; Gearhart, C A; Fulton, S; Mattie, D R

    2012-01-01

    Both laboratory and epidemiological studies published over the past two decades have identified the risk of excess hearing loss when specific chemical contaminants are present along with noise. The objective of this study was to evaluate the potency of JP-8 jet fuel to enhance noise-induced hearing loss (NIHL) using inhalation exposure to fuel and simultaneous exposure to either continuous or intermittent noise exposure over a 4-wk exposure period using both male and female Fischer 344 rats. In the initial study, male (n = 5) and female (n = 5) rats received inhalation exposure to JP-8 fuel for 6 h/d, 5 d/wk for 4 wk at concentrations of 200, 750, or 1500 mg/m³. Parallel groups of rats also received nondamaging noise (constant octave band noise at 85 dB(lin)) in combination with the fuel, noise alone (75, 85, or 95 dB), or no exposure to fuel or noise. Significant concentration-related impairment of auditory function measured by distortion product otoacoustic emissions (DPOAE) and compound action potential (CAP) threshold was seen in rats exposed to combined JP-8 plus noise exposure when JP-8 levels of 1500 mg/m³ were presented with trends toward impairment seen with 750 mg/m³ JP-8 + noise. JP-8 alone exerted no significant effect on auditory function. In addition, noise was able to disrupt the DPOAE and increase auditory thresholds only when noise exposure was at 95 dB. In a subsequent study, male (n = 5 per group) and female (n = 5 per group) rats received 1000 mg/m³ JP-8 for 6 h/d, 5 d/wk for 4 wk with and without exposure to 102 dB octave band noise that was present for 15 min out of each hour (total noise duration 90 min). Comparisons were made to rats receiving only noise, and thosereceiving no experimental treatment. Significant impairment of auditory thresholds especially for high-frequency tones was identified in the male rats receiving combined treatment. This study provides a basis for estimating excessive hearing loss under

  19. Adrenal-derived stress hormones modulate ozone-induced ...

    Science.gov (United States)

    Ozone-induced systemic effects are modulated through activation of the neuro-hormonal stress response pathway. Adrenal demedullation (DEMED)or bilateral total adrenalectomy (ADREX) inhibits systemic and pulmonary effect of acute ozone exposure. To understand the influence of adrenal-derived stress hormones in mediating ozone-induced lung injury/inflammation, we assessed global gene expression (mRNA sequencing) and selected proteins in lung tissues from male Wistar-Kyoto rats that underwent DEMED, ADREX, or sham surgery (SHAM)prior to their exposure to air or ozone (1 ppm),4 h/day for 1 or 2days. Ozone exposure significantly changed the expression of over 2300 genes in lungs of SHAM rats, and these changes were markedly reduced in DEMED and ADREX rats. SHAM surgery but not DEMED or ADREX resulted in activation of multiple ozone-responsive pathways, including glucocorticoid, acute phase response, NRF2, and Pl3K-AKT.Predicted targets from sequencing data showed a similarity between transcriptional changes induced by ozone and adrenergic and steroidal modulation of effects in SHAM but not ADREX rats. Ozone-induced Increases in lung 116 in SHAM rats coincided with neutrophilic Inflammation, but were diminished in DEMED and ADREX rats. Although ozone exposure in SHAM rats did not significantly alter mRNA expression of lfny and 11-4, the IL-4 protein and ratio of IL-4 to IFNy (IL-4/IFNy) proteins increased suggesting a tendency for a Th2 response. This did not occur

  20. Destruction of enzymatic activities of corn and soybean leaves exposed to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Leffler, H R; Cherry, J H

    1974-01-01

    Experiments were conducted to determine the effects of a single ozone exposure on selected enzymatic activities and chlorophyll contents of corn and soybean seedlings. Both nitrite reductase activity and chlorophyll content of the seedlings were found to be quite sensitive to ozonation and were seen to decrease as much as 50% after exposure to 80 parts per hundred million (pphm) ozone. After exposure to lower levels of ozone, less-pronounced decreases were observed. Nitrate reductase activity was reduced only after exposure to seedling leaf tissues to high concentrations of ozone. These results are discussed in relation to the concept of a two-phase response to oxidant exposure. The first phase is at the chloroplast level and is quite sensitive to the low as well as the high concentrations of ozone; the second is at the cellular level and is relatively resistant to all but the highest ozone concentrations. 27 references, 2 tables.

  1. Characterization of a Newly Developed Contrast Enhancement Material for G-line Exposure

    Science.gov (United States)

    Nakase, Makoto; Niki, Hirokazu; Satoh, Takashi; Kumagae, Akitoshi

    1987-02-01

    The bleaching characteristics for a contrast enhancement layer (CEL) material were succesfully described by parameters A, B and C; these were used for the modeling of a positive photoresist exposure. As a result, it was clarified that both the A and C values should be large, but the B value must be as small as possible. According to the obtained information, a new CEL material was proposed, which consists of the diazonium compound and the alkyl modified phenol resin. Using the composed CEL material, a submicron resist pattern with a steep profile was obtained. Furthermore, it was found that the development latitude increases, but that the exposure latitude does not change upon using the CEL.

  2. Enhancement of exposure to radon progeny as a consequence of passive smoking

    International Nuclear Information System (INIS)

    Moghissi, A.A.; Seiler, M.C.

    1989-01-01

    Among indoor air pollutants, radon and tobacco smoke take dominant positions. Because radon decay products have a relatively short residence time in air, the extent of the equilibrium between radon and its daughter products is linearly proportional to the carcinogenic risk, at least at low exposure levels. The relevant factor is the equilibrium factor F. This paper discusses the enhancement of radon exposure as a result of the presence of particulate matter originating from tobacco smoke. The presence of tobacco smoke provides a mechanism for radon progeny to be attached to inhalable particles and to remain in indoor air for a prolonged time. The results of our study indicate a significant increase in F as a consequence of passive smoking. These modeling efforts are consistent with the experimental data reported previously

  3. The Antarctic ozone hole

    International Nuclear Information System (INIS)

    Jones, Anna E

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For the historical perspective, the events leading up to the discovery of the 'hole' are presented, as well as the response from the international community and the measures taken to protect the ozone layer now and into the future

  4. Effects of moderately enhanced levels of ozone on the acyl lipid composition and dynamical properties of plasma membranes isolated from garden pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Hellgren, Lars; Sellden, G.; Sandelius, A.S.

    2001-01-01

    Plasma membranes were isolated from leaves of 16-day-old garden pea, Pisum sativum L., that had been grown in the absence or presence of 65 nl l(-1) ozone for 4 days prior to membrane isolation, Plasma membranes from ozone-fumigated plants contained significantly more acyl lipids per protein than....../stigmasterol and lipid/protein ratios, and suggesting that ozone-fumigated pea plants may be more susceptible to freezing injuries....... lipids, as well as in PC and PE, The amount of free sterols per protein was unaltered, but the percentage of campesterol increased, concomitant with a decrease in stigmasterol, The dynamical properties of the isolated plasma membranes were assessed using Laurdan fluorescence spectroscopy, which monitors...

  5. Radioactivity levels in Indian coal and some technologically enhanced exposure to natural radiation environment of India

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Mishra, U.C.

    1988-01-01

    The summary of results of gamma-spectrometric measurements of natural radioactivity levels in coal from mines, coal, fly-ash, slag and soil samples from thermal power plants in India are presented. These constitute the sources of technologic ally enhanced exposures to natural radiation. Brief description of sampling and measurement procedure is given. Radiation dose to the population from coal fired power plants for electricity generation have been calculated using the model developed by UNSCEAR and ORNL reports with correction for local population density. (author). 13 refs., 7 tabs., 8 figs

  6. The key role of extinction learning in anxiety disorders: behavioral strategies to enhance exposure-based treatments.

    Science.gov (United States)

    Pittig, Andre; van den Berg, Linda; Vervliet, Bram

    2016-01-01

    Extinction learning is a major mechanism for fear reduction by means of exposure. Current research targets innovative strategies to enhance fear extinction and thereby optimize exposure-based treatments for anxiety disorders. This selective review updates novel behavioral strategies that may provide cutting-edge clinical implications. Recent studies provide further support for two types of enhancement strategies. Procedural enhancement strategies implemented during extinction training translate to how exposure exercises may be conducted to optimize fear extinction. These strategies mostly focus on a maximized violation of dysfunctional threat expectancies and on reducing context and stimulus specificity of extinction learning. Flanking enhancement strategies target periods before and after extinction training and inform optimal preparation and post-processing of exposure exercises. These flanking strategies focus on the enhancement of learning in general, memory (re-)consolidation, and memory retrieval. Behavioral strategies to enhance fear extinction may provide powerful clinical applications to further maximize the efficacy of exposure-based interventions. However, future replications, mechanistic examinations, and translational studies are warranted to verify long-term effects and naturalistic utility. Future directions also comprise the interplay of optimized fear extinction with (avoidance) behavior and motivational antecedents of exposure.

  7. Chronic ozone exposure alters the secondary metabolite profile, antioxidant potential, anti-inflammatory property, and quality of red pepper fruit from Capsicum baccatum.

    Science.gov (United States)

    Bortolin, Rafael Calixto; Caregnato, Fernanda Freitas; Divan Junior, Armando Molina; Zanotto-Filho, Alfeu; Moresco, Karla Suzana; Rios, Alessandro de Oliveira; Salvi, Aguisson de Oliveira; Ortmann, Caroline Flach; de Carvalho, Pâmela; Reginatto, Flávio Henrique; Gelain, Daniel Pens; Moreira, José Cláudio Fonseca

    2016-07-01

    Tropospheric ozone (O3) background concentrations have increased since pre-industrial times, reaching phytotoxic concentrations in many regions globally. However, the effect of high O3 concentrations on quality of fruit and vegetables remains unknown. Here, we evaluated whether O3 pollution alters the quality of Capsicum baccatum peppers by changing the secondary compound profiles and biological activity of the fruit. C. baccatum pepper plants were exposed to ozone for 62 days in an open-top chamber at a mean O3 concentration of 171.6µg/m(3). Capsaicin levels decreased by 50% in the pericarp, but remained unchanged in the seeds. In contrast, the total carotenoid content increased by 52.8% in the pericarp. The content of total phenolic compounds increased by 17% in the pericarp. The total antioxidant potential decreased by 87% in seeds of O3-treated plants. The seeds contributed more than the pericarp to the total radical-trapping antioxidant potential and total antioxidant reactivity. O3 treatment impaired the ferric-reducing antioxidant power of the seeds and reduced NO(•)-scavenging activity in the pericarp. However, O3 treatment increased ferrous ion-chelating activity and hydroxyl radical-scavenging activity in the pericarp. Our results confirm that O3 alters the secondary metabolite profile of C. baccatum pepper fruits and, consequently, their biological activity profile. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Ozone mass transfer and kinetics experiments

    International Nuclear Information System (INIS)

    Bollyky, L.J.; Beary, M.M.

    1981-12-01

    Experiments were conducted at the Hanford Site to determine the most efficient pH and temperature levels for the destruction of complexants in Hanford high-level defense waste. These complexants enhance migration of radionuclides in the soil and inhibit the growth of crystals in the evaporator-crystallizer. Ozone mass transfer and kinetics tests have been outlined for the determination of critical mass transfer and kinetics parameters of the ozone-complexant reaction

  9. Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures.

    Science.gov (United States)

    Allen, Michael Todd; Miller, Daniel P

    2016-01-01

    Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from conditioned stimulus (CS) or unconditioned stimulus (US) alone pre-exposures (Holloway et al., 2012). US alone pre-exposures disrupt subsequent conditioned response (CR) acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al. (2012) reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioral Inhibition (AMBI). Sixty-six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI) individuals exhibited enhanced proactive interference as compared to non-inhibited (NI) individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible

  10. Perinatal exposure to methoxychlor enhances adult cognitive responses and hippocampal neurogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Mariangela eMartini

    2014-06-01

    Full Text Available During perinatal life, sex steroids, such as estradiol, have marked effects on the development and function of the nervous system. Environmental estrogens or xenoestrogens are man-made chemicals, which animal and human population encounter in the environment and which are able to disrupt the functioning of the endocrine system. Scientific interest in the effects of exposure to xenoestrogens has focused more on fertility and reproductive behaviors, while the effects on cognitive behaviors have received less attention. Therefore, the present study explored whether the organochlorine insecticide Methoxychlor (MXC, with known xenoestrogens properties, administered during the perinatal period (from gestational day 11 to postnatal day 8 to pregnant-lactating females, at an environmentally relevant dose (20µg/kg (body weight/day, would also affect learning and memory functions depending on the hippocampus of male and female offspring mice in adulthood. When tested in adulthood, MXC perinatal exposure led to an increase in anxiety-like behavior and in short-term spatial working memory in both sexes. Emotional learning was also assessed using a contextual fear paradigm and MXC treated male and female mice showed an enhanced freezing behavior compared to controls. These results were correlated with an increased survival of adult generated cells in the adult hippocampus. In conclusion, our results show that perinatal exposure to an environmentally relevant dose of MXC has an organizational effect on hippocampus-dependent memory and emotional behaviors.

  11. Interaction between ozone and airborne particulate matter in office air

    DEFF Research Database (Denmark)

    Mølhave, Lars; Kjærgaard, Søren K.; Sigsgaard, Torben

    2005-01-01

    This study investigated the hypotheses that humans are affected by air pollution caused by ozone and house dust, that the effect of simultaneous exposure to ozone and dust in the air is larger than the effect of these two pollutants individually, and that the effects can be measured as release of...

  12. A passive sampler for atmospheric ozone

    International Nuclear Information System (INIS)

    Grosjean, D.; Hisham, M.W.M.

    1992-01-01

    A simple, cost-effective passive sampler has been developed for the determination of atmospheric ozone. This passive sampler is based on a colorant which fades upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Direct, on-site measurements are possible, and no chemical analyses are needed. Sampler design and validation studies have been carried out and included quantitative determination of color change vs exposure time (1-8 days), color change vs. ozone concentration (30-350 ppb), and response to changes in sampler configuration that modify the passive sampling rate. With indigo carmine as the colorant, the detection limits are 30 ppb. day and 120 ppb. day using a plastic grid and Teflon filter, respectively, as diffusion barriers. Interferences from nitrogen dioxide, formaldehyde and peroxyacetyl nitrate are 15, 4 and 16%, respectively, thus resulting in a negligible bias when measuring ozone in ambient air

  13. Modeling ozone bioindicator injury with microscale and landscape-scale explanatory variables: A logistic regression approach

    Science.gov (United States)

    John W. Coulston

    2011-01-01

    Tropospheric ozone occurs at phytotoxic levels in the United States (Lefohn and Pinkerton 1988). Several plant species, including commercially important timber species, are sensitive to elevated ozone levels. Exposure to elevated ozone can cause growth reduction and foliar injury and make trees more susceptible to secondary stressors such as insects and pathogens (...

  14. Ozone and sulphur dioxide effects on leaf water potential of Petunia

    Energy Technology Data Exchange (ETDEWEB)

    Elkiey, T.; Ormrod, D.P.

    1979-01-01

    Three cultivars of Petunia hydrida Vilm., of differing ozone visible injury sensitivity, were exposed to 40 parts per hundred million (pphm) ozone and/or 80 pphm SO/sub 2/ for 4 h to study the relationships of leaf water potential, pollutant exposure, and cultivar sensitivity. Ozone substantially decreased leaf water potential in cv White Cascade but not in cv Capri or White Magic. Sulphur dioxide did not affect leaf water potential but delayed ozone-induced changes. Cultivar sensitivity to ozone-induced changes in leaf water potential was not related to cultivar sensitivity to ozone-induced visible injury.

  15. Ozone Antimicrobial Efficacy

    Science.gov (United States)

    Ozone is a potent germicide that has been used extensively for water purification. In Europe, 90 percent of the municipal water systems are treated with ozone, and in France, ozone has been used to treat drinking water since 1903. However, there is limited information on the bioc...

  16. Advanced treatment of biotreated textile industry wastewater with ozone, virgin/ozonated granular activated carbon and their combination.

    Science.gov (United States)

    Arslan-Alaton, Idil; Seremet, Ozden

    2004-01-01

    Biotreated textile wastewater (CODo = 248 mg L(-1); TOCo = 58 mg L(-1); A620 = 0.007 cm(-1); A525 = 0.181 cm(-1); A436 = 0.198 cm(-1)) was subjected to advanced treatment with ozonation, granular activated carbon (GAC) adsorption in serial and simultaneous applications. Experiments were conducted to investigate the effects of applied ozone dose, ozone absorption rate, specific ozone absorption efficiency, GAC dose, and reaction pH on the treatment performance of the selected tertiary treatment scheme. In separate experiments, the impact of virgin GAC ozonation on its adsorptive capacity for biotreated and biotreated + ozonated textile effluent was also investigated. Ozonation appeared to be more effective for decolorization (kd = 0.15 min(-1) at pH = 3), whereas GAC adsorption yielded higher COD removal rates (54% at pH = 3). It was also found that GAC addition (4 g/L) at pH = 7 and 9 enhanced the COD abatement rate of the ozonation process significantly and that the sequential application of ozonation (at pH = 3-11, 675 mg L(-1) O3) followed by GAC adsorption (at pH = 3-7, 10 g L(-1) GAC) resulted in the highest treatment performances both in terms of color and COD reduction. Simultaneous application of GAC and ozone at acidic and alkaline pH seriously inhibited COD abatement rates as a consequence of competitive adsorption and partial oxidation of textile components and GAC. It could also be established that ozone absorption efficiency decreased after color removal was complete. Ozonation of biotreated textile wastewater with 113 mg L(-1) ozone resulted in an appreciable enhancement of GAC adsorptive capacity in terms of residual color removal. Ozonation of GAC at relatively low doses (= 10.8 mg/g GAC) did not improve its overall adsorption capacity.

  17. Ozone injury increases infection of geranium leaves by Botrytis cinerea

    Energy Technology Data Exchange (ETDEWEB)

    Manning, W.J.; Feder, W.A.; Perkins, I.

    1970-04-01

    Detached and attached, inoculated and noninoculated, ozone-injured and noninjured leaves from the lower, middle, and terminal regions of plants of geranium cultivars Enchantress and White Mountain were observed for infection by Botrytis cinerea. Previous exposure to ozone did not appreciably influence the susceptibility of leaves of either geranium cultivar to infection by B. cinerea, unless there was visible ozone injury. Ozone-injured, necrotic tissues on older attached and detached geranium leaves of both cultivars served as infection courts for B. cinerea. 14 references, 1 table.

  18. Earth's ozone layer

    International Nuclear Information System (INIS)

    Lasa, J.

    1991-01-01

    The paper contain the actual results of investigations of the influence of the human activity on the Earth's ozone layer. History of the ozone measurements and of the changes in its concentrations within the last few years are given. The influence of the trace gases on both local and global ozone concentrations are discussed. The probable changes of the ozone concentrations are presented on the basis of the modelling investigations. The effect of a decrease in global ozone concentration on human health and on biosphere are also presented. (author). 33 refs, 36 figs, 5 tabs

  19. Urban Summertime Ozone of China: Peak Ozone Hour and Nighttime Mixing

    Science.gov (United States)

    Qu, H.; Wang, Y.; Zhang, R.

    2017-12-01

    We investigate the observed diurnal cycle of summertime ozone in the cities of China using a regional chemical transport model. The simulated daytime ozone is in general agreement with the observations. Model simulations suggest that the ozone peak time and peak concentration are a function of NOx (NO + NO2) and volatile organic compound (VOC) emissions. The differences between simulated and observed ozone peak time and peak concentration in some regions can be applied to understand biases in the emission inventories. For example, the VOCs emissions are underestimated over the Pearl River Delta (PRD) region, and either NOx emissions are underestimated or VOC emissions are overestimated over the Yangtze River Delta (YRD) regions. In contrast to the general good daytime ozone simulations, the simulated nighttime ozone has a large low bias of up to 40 ppbv. Nighttime ozone in urban areas is sensitive to the nocturnal boundary-layer mixing, and enhanced nighttime mixing (from the surface to 200-500 m) is necessary for the model to reproduce the observed level of ozone.

  20. Music exposure improves spatial cognition by enhancing the BDNF level of dorsal hippocampal subregions in the developing rats.

    Science.gov (United States)

    Xing, Yingshou; Chen, Wenxi; Wang, Yanran; Jing, Wei; Gao, Shan; Guo, Daqing; Xia, Yang; Yao, Dezhong

    2016-03-01

    Previous research has shown that dorsal hippocampus plays an important role in spatial memory process. Music exposure can enhance brain-derived neurotrophic factor (BDNF) expression level in dorsal hippocampus (DH) and thus enhance spatial cognition ability. But whether music experience may affect different subregions of DH in the same degree remains unclear. Here, we studied the effects of exposure to Mozart K.448 on learning behavior in developing rats using the classical Morris water maze task. The results showed that early music exposure could enhance significantly learning performance of the rats in the water maze test. Meanwhile, the BDNF/TrkB level of dorsal hippocampus CA3 (dCA3) and dentate gyrus (dDG) was significantly enhanced in rats exposed to Mozart music as compared to those without music exposure. In contrast, the BDNF/TrkB level of dorsal hippocampus CA1 (dCA1) was not affected. The results suggest that the spatial memory improvement by music exposure in rats may be associated with the enhanced BDNF/TrkB level of dCA3 and dDG. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

    DEFF Research Database (Denmark)

    Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

    2013-01-01

    . The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality......Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings...

  2. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

    International Nuclear Information System (INIS)

    Pasqualini, Stefania; Tedeschini, Emma; Frenguelli, Giuseppe; Wopfner, Nicole; Ferreira, Fatima; D'Amato, Gennaro; Ederli, Luisa

    2011-01-01

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O 3 ) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O 3 fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O 3 fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O 3 , determined from the mRNA levels of the major allergens. We conclude that O 3 can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: → O 3 reduces the viability of ragweed pollen. → ROS and allergens of ragweed pollen were not affected by O 3 exposure. → O 3 enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. → O 3 increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

  3. Repeated nicotine exposure enhances reward-related learning in the rat.

    Science.gov (United States)

    Olausson, Peter; Jentsch, J David; Taylor, Jane R

    2003-07-01

    Repeated exposure to addictive drugs causes neuroadaptive changes in cortico-limbic-striatal circuits that may underlie alterations in incentive-motivational processes and reward-related learning. Such drug-induced alterations may be relevant to drug addiction because enhanced incentive motivation and increased control over behavior by drug-associated stimuli may contribute to aspects of compulsive drug-seeking and drug-taking behaviors. This study investigated the consequences of repeated nicotine treatment on the acquisition and performance of Pavlovian discriminative approach behavior, a measure of reward-related learning, in male rats. Water-restricted rats were trained to associate a compound conditioned stimulus (tone+light) with the availability of water (the unconditioned stimulus) in 15 consecutive daily sessions. In separate experiments, rats were repeatedly treated with nicotine (0.35 mg/kg, s.c.) either (1) prior to the onset of training, (2) after each daily training session was completed (ie postsession injections), or (3) received nicotine both before the onset of training as well as after each daily training session. In this study, all nicotine treatment schedules increased Pavlovian discriminative approach behavior and, thus, prior repeated exposure to nicotine, repeated postsession nicotine injections, or both, facilitated reward-related learning.

  4. Exposure to Acute Stress Enhances Decision-Making Competence: Evidence for the Role of DHEA

    Science.gov (United States)

    Shields, Grant S.; Lam, Jovian C. W.; Trainor, Brian C.; Yonelinas, Andrew P.

    2016-01-01

    Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol. PMID:26874561

  5. Enhanced Deformation of Azobenzene-Modified Liquid Crystal Polymers under Dual Wavelength Exposure: A Photophysical Model

    Science.gov (United States)

    Liu, Ling; Onck, Patrick R.

    2017-08-01

    Azobenzene-embedded liquid crystal polymers can undergo mechanical deformation in response to ultraviolet (UV) light. The natural rodlike trans state azobenzene absorbs UV light and isomerizes to a bentlike cis state, which disturbs the order of the polymer network, leading to an anisotropic deformation. The current consensus is that the magnitude of the photoinduced deformation is related to the statistical building up of molecules in the cis state. However, a recent experimental study [Liu and Broer, Nat. Commun. 6 8334 (2015)., 10.1038/ncomms9334] shows that a drastic (fourfold) increase of the photoinduced deformation can be generated by exposing the samples simultaneously to 365 nm (UV) and 455 nm (visible) light. To elucidate the physical mechanism that drives this increase, we develop a two-light attenuation model and an optomechanical constitutive relation that not only accounts for the statistical accumulation of cis azobenzenes, but also for the dynamic trans-cis-trans oscillatory isomerization process. Our experimentally calibrated model predicts that the optimal single-wavelength exposure is 395 nm light, a pronounced shift towards the visible spectrum. In addition, we identify a range of optimal combinations of two-wavelength lights that generate a favorable response for a given amount of injected energy. Our model provides mechanistic insight into the different (multi)wavelength exposures used in experiments and, at the same time, opens new avenues towards enhanced, multiwavelength optomechanical behavior.

  6. Exposure to acute stress enhances decision-making competence: Evidence for the role of DHEA.

    Science.gov (United States)

    Shields, Grant S; Lam, Jovian C W; Trainor, Brian C; Yonelinas, Andrew P

    2016-05-01

    Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Exposure to odors of rivals enhances sexual motivation in male giant pandas.

    Directory of Open Access Journals (Sweden)

    Xiaoxing Bian

    Full Text Available Males will alter their mating behavior to cope with the presence of their competitors. Even exposure to odors from potential competitors can greatly increase male ejaculate expenditure in a variety of animals including insects, fishes, birds and rodents. Major efforts have been made to examine males' plastic responses to sperm competition and its fitness benefits. However, the effects of competitor absence on male's sexual motivation and behaviors remain unclear, which has been proposed to be one of the causes for the poor sexual performance of some captive mammals. This study revealed that sexual motivation can be greatly enhanced in captive male giant pandas (Ailuropoda melanoleuca by exposure to chemosensory cues from either one or three conspecifics males. It had been shown that potential rivals' odors increased males' chemosensory investigation behavior, as well as their observing, following and sniffing behaviors towards estrous females. Behaviors changed regardless of the number of rivals (one or three. Our results demonstrate the effects of potential competition on male giant pandas' sexual motivation and behavioral coping strategy. We anticipate that our research will provide a fresh insight into the mechanisms underlying poor sexual performance in male captive mammals, and valuable information for the practical management and ex situ conservation of endangered species.

  8. Shelf life characteristics of bread produced from ozonated wheat flour.

    Science.gov (United States)

    Obadi, Mohammed; Zhu, Ke-Xue; Peng, Wei; Sulieman, Abdellatif A; Mahdi, Amer Ali; Mohammed, Khalid; Zhou, Hui-Ming

    2017-11-13

    The objective of this work was to study the effect of ozone treatment on the quality of bread and its shelf life. Flour was treated with ozone gas a rate of 5 L/min for 5, 15, 25, 35, and 45 min. Baking studies showed that bread made from flour treated with ozone for 15 min exhibited improved quality properties (in terms of specific volume, bread color, and crumb cell numbers). Exposure to ozone for shorter times did not cause obvious changes in the major volatile compounds of bread. A shelf life tests showed that ozone gas treatment influenced the extent of starch crystallinity. The relative starch crystallinity of bread made from flour treated with ozone for 15 min was lower than the control value, as were the hardness, springiness, and cohesiveness. Microscopic examination of crumb structure revealed remarkable differences between control and treated breads. Although ozone is a naturally occurring substance found in the atmosphere, ozone can also be produced synthetically. Recently, ozone has come to be regarded as a new treatment for flour. Especially in countries where the chlorination is forbidden, ozone treatment may be of a great interest if it were associated with significant and reliable changes in flour. Ozone treatment of wheat flour tends to improve bread shelf life and quality in terms of physiochemical, baking properties, X-ray diffraction data, volatile compound levels, crumb structure, and textural characteristics. Given such findings, desirable shelf life and bread qualities may be achieved when ozone is used as a flour oxidant prior to bread baking. Analyses of the effects of ozone gas on treatment of flour on bread shelf life and quality would aid the production of high quality and extend the shelf life of bread. © 2017 Wiley Periodicals, Inc.

  9. Racial isolation and exposure to airborne particulate matter and ozone in understudied US populations: Environmental justice applications of downscaled numerical model output.

    Science.gov (United States)

    Bravo, Mercedes A; Anthopolos, Rebecca; Bell, Michelle L; Miranda, Marie Lynn

    2016-01-01

    Researchers and policymakers are increasingly focused on combined exposures to social and environmental stressors, especially given how often these stressors tend to co-locate. Such exposures are equally relevant in urban and rural areas and may accrue disproportionately to particular communities or specific subpopulations. To estimate relationships between racial isolation (RI), a measure of the extent to which minority racial/ethnic group members are exposed to only one another, and long-term particulate matter with an aerodynamic diameter of poverty. RI is associated with higher 5year estimated PM2.5 concentrations in urban, suburban, and rural census tracts, adding to evidence that segregation is broadly associated with disparate air pollution exposures. Disproportionate burdens to adverse exposures such as air pollution may be a pathway to racial/ethnic disparities in health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Elevated CO{sub 2} does not ameliorate effects of ozone on carbon allocation in Pinus halepensis and Betula pendula in symbiosis with Paxillus involutus

    Energy Technology Data Exchange (ETDEWEB)

    Kytoeviita, M.M. [Oulu Univ., Dept. of Biology, Oulu (Finland); Pelloux, J.; Fontaine, V.; Botton, B.; Dizengremel, P. [Univ. Henri Poincare-Nancy, Lab. de Biologie Forestiere Associe INRA, Vandoeuvre-les-Nancy (France)

    1999-07-01

    The effect of 700 {mu}mol CO{sub 2} mol{sup -1}, 200 nmol ozone mol{sup -1} and a combination of the two on carbon allocation was examined in Pinus halepensis co-cultured with Betula pendula in symbiosis with the ectomycorrhizal fungus Paxillus involutus. The results show that under low nutrient and ozone levels, elevated CO{sub 2} has no effect on the growth of B. pendula or P. halepensis seedlings nor on net carbon partitioning between plant parts. Elevated CO{sub 2} did not enhance the growth of the fungus in symbiosis with the birch. On the other hand, ozone had a strong negative effect on the growth of the birch, which corresponded with the significantly reduced growth rates of the fungus. Exposure to elevated CO{sub 2} did not ameliorate the negative effects of ozone on birch; in contrast, it acted as an additional stress factor. Neither ozone nor CO{sub 2} had significant effects on biomass accumulation in the pine seedlings. Ozone stimulated the spread of mycorrhizal infection from the birch seedlings to neighbouring pines and had no statistically significant effects on phosphoenolpyruvate carboxylase (PEPC) or ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity in the pine needles or on PEPC activity in pine roots. (au)

  11. Vaccination Enhances Early Immune Responses in White Shrimp Litopenaeus vannamei after Secondary Exposure to Vibrio alginolyticus

    Science.gov (United States)

    Lin, Yong-Chin; Chen, Jiann-Chu; Morni, Wan Zabidii W.; Putra, Dedi Fazriansyah; Huang, Chien-Lun; Li, Chang-Che; Hsieh, Jen-Fang

    2013-01-01

    Background Recent work suggested that the presence of specific memory or some form of adaptive immunity occurs in insects and shrimp. Hypervariable pattern recognition molecules, known as Down syndrome cell adhesion molecules, are able to mount specific recognition, and immune priming in invertebrates. In the present study, we attempted to understand the immune response pattern of white shrimp Litopenaeus vannamei which received primary (PE) and secondary exposure (SE) to Vibrio alginolyticus. Methodology Immune parameters and proliferation of haematopoietic tissues (HPTs) of shrimp which had received PE and SE to V. alginolyticus were measured. In the PE trial, the immune parameters and proliferation of HPTs of shrimp that received heat-killed V. alginolyticus (HVa) and formalin-inactivated V. alginolyticus (FVa) were measured. Mortality, immune parameters and proliferation of HPTs of 7-day-HVa-PE shrimp (shrimp that received primary exposure to HVa after 7 days) and 7-day-FVa-PE shrimp (shrimp that received primary exposure to FVa after 7 days) following SE to live V. alginolyticus (LVa) were measured. Phagocytic activity and clearance efficiency were examined for the 7∼35-day-HVa-PE and FVa-PE shrimp. Results HVa-receiving shrimp showed an earlier increase in the immune response on day 1, whereas FVa-receiving shrimp showed a late increase in the immune response on day 5. The 7-day-FVa-PE shrimp showed enhancement of immunity when encountering SE to LVa, whereas 7-day-HVa-PE shrimp showed a minor enhancement in immunity. 7-day-FVa-PE shrimp showed higher proliferation and an HPT mitotic index. Both phagocytic activity and clearance maintained higher for both HVa-PE and FVa-PE shrimp after 28 days. Conclusions HVa- and FVa-receiving shrimp showed the bacteria agglutinated prior to being phagocytised. FVa functions as a vaccine, whereas HVa functions as an inducer and can be used as an immune adjuvant. A combined mixture of FVa and HVa can serve as a

  12. Oxygen vacancies enabled enhancement of catalytic property of Al reduced anatase TiO{sub 2} in the decomposition of high concentration ozone

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yanhua; Zhang, Xiaolei [Shanghai Institute of Technology, Shanghai 200235 (China); Chen, Li [East China Normal University, Shanghai 200062 (China); Wang, Xiaorui [Shanghai Institute of Technology, Shanghai 200235 (China); Zhang, Na, E-mail: nzhang@sit.edu.cn [Shanghai Institute of Technology, Shanghai 200235 (China); Liu, Yufeng [Shanghai Institute of Technology, Shanghai 200235 (China); Fang, Yongzheng, E-mail: fyz1003@sina.com [Shanghai Institute of Technology, Shanghai 200235 (China)

    2017-06-15

    The catalytic decomposition of gaseous ozone (O{sub 3}) is investigated using anatase TiO{sub 2} (A-TiO{sub 2}) and Aluminum-reduced A-TiO{sub 2} (ARA-TiO{sub 2}) at high concentration and high relative humidity (RH) without light illumination. Compared with the pristine A-TiO{sub 2}, the ARA-TiO{sub 2} sample possesses a unique crystalline core-amorphous shell structure. It is proved to be an excellent solar energy “capture” for solar thermal collectors due to lots of oxygen vacancies. The results indicate that the overall decomposition efficiency of O{sub 3} without any light irradiation has been greatly improved from 4.8% on A-TiO{sub 2} to 100% on ARA-TiO{sub 2} under the RH=100% condition. The ozone conversion over T500/ARA-TiO{sub 2} catalyst is still maintained at 95% after a 72 h test under the reaction condition of 18.5 g/m{sup 3} ozone initial concentration, and RH=90%. The results can be explained that T500/ARA-TiO{sub 2} possesses the largest amorphous contour, the lowest crystallinity, the most surface-active Ti{sup 3+}/T{sup i4+}couples, and the most oxygen vacancies. This result opens a new door to widen the application of TiO{sub 2} in the thermal-catalytic field. - Graphical abstract: The anatase-TiO{sub 2} with various oxidation states and oxygen vacancies have been obtained by aluminum-reduction, and the decomposition efficiency of O{sub 3} has been greatly improved from 4.8% to 100% without irradiation under the RH=100% condition. - Highlights: • The decomposition of gaseous ozone over Al reduced TiO2 (ARA-TiO{sub 2}) is firstly reported. • The decomposition efficiency is up to 100% without any light irradiation on ARA-TiO{sub 2} under RH=100% condition. • The ozone conversion is maintained at 95% after a 72 h test, when C{sub inlet}=18.5 g/m{sup 3} and RH=90%.

  13. Effects of mineral nutrients on ozone susceptibility of Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Craker, L.E.

    1971-01-01

    Susceptibility of Lemna minor L. to ozone injury was influenced by the mineral nutrients available to the Lemna plants. Additional nitrogen or additional iron in the nutrient media respectively enhanced or reduced chlorophyll loss of Lemna plants fumigated with ozone. Lemna plants growing on a nutrient medium lacking copper had significantly less injury from ozone fumigation than Lemna plants growing on a complete nutrient medium. There were apparent interactions among phosphorus and potassium nutrient levels in determing the Lemna plant's susceptibility to ozone.

  14. Stratospheric ozone transboundary transport to upper troposphere North Africa

    CSIR Research Space (South Africa)

    Ture, K

    2011-09-01

    Full Text Available will identify the causes and sources of MOZAIC ozone enhancements at upper tropospheric North Africa (20-350 N). In addition the paper will address the modes of transport of ozone rich airmass sampled by MOZAIC at mid latitude and North Africa....

  15. The stratospheric ozone and the ozone layer

    International Nuclear Information System (INIS)

    Zea Mazo, Jorge Anibal; Leon Aristizabal Gloria Esperanza; Eslava Ramirez Jesus Antonio

    2000-01-01

    An overview is presented of the principal characteristics of the stratospheric ozone in the Earth's atmosphere, with particular emphasis on the tropics and the ozone hole over the poles. Some effects produced in the atmosphere as a consequence of the different human activities will be described, and some data on stratospheric ozone will be shown. We point out the existence of a nucleus of least ozone in the tropics, stretching from South America to central Africa, with annual mean values less than 240 DU, a value lower than in the middle latitudes and close to the mean values at the South Pole. The existence of such a minimum is confirmed by mean values from measurements made on satellites or with earthbound instruments, for different sectors in Colombia, like Medellin, Bogota and Leticia

  16. Exposure to Experimental Preeclampsia in Mice Enhances the Vascular Response to Future Injury

    Science.gov (United States)

    Pruthi, Dafina; Khankin, Eliyahu V.; Blanton, Robert M.; Aronovitz, Mark; Burke, Suzanne D.; McCurley, Amy; Karumanchi, S. Ananth; Jaffe, Iris Z.

    2015-01-01

    Cardiovascular disease (CVD) remains the leading killer of women in developed nations. One gender-specific risk factor is preeclampsia (PE), a syndrome of hypertension and proteinuria that complicates 5% of pregnancies. Although PE resolves after delivery, exposed women are at increased long term risk of premature CVD and mortality. Preexisting CVD risk factors are associated with increased risk of developing PE but whether PE merely uncovers risk or contributes directly to future CVD remains a critical unanswered question. A mouse PE model was used to test the hypothesis that PE causes an enhanced vascular response to future vessel injury. A PE-like state was induced in pregnant CD1 mice by overexpressing soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating anti-angiogenic protein that induces hypertension and glomerular disease resembling human PE. Two months post-partum, sFlt-1 levels and blood pressure normalized and cardiac size and function by echocardiography and renal histology were indistinguishable in PE-exposed compared to control mice. Mice were then challenged with unilateral carotid injury. PE-exposed mice had significantly enhanced vascular remodeling with increased vascular smooth muscle cell proliferation (180% increase, P<0.01) and vessel fibrosis (216% increase, P<0.001) compared to control pregnancy. In the contralateral uninjured vessel, there was no difference in remodeling after exposure to PE. These data support a new model in which vessels exposed to PE retain a persistently enhanced vascular response to injury despite resolution of PE after delivery. This new paradigm may contribute to the substantially increased risk of CVD in woman exposed to PE. PMID:25712723

  17. Ozone impedes the ability of a herbivore to find its host

    International Nuclear Information System (INIS)

    Fuentes, Jose D; Zenker, John; Roulston, T’ai H

    2013-01-01

    Plant-emitted hydrocarbons mediate several key interactions between plants and insects. They enhance the ability of pollinators and herbivores to locate suitable host plants, and parasitoids to locate herbivores. While plant volatiles provide strong chemical signals, these signals are potentially degraded by exposure to pollutants such as ozone, which has increased in the troposphere and is projected to continue to increase over the coming decades. Despite the potential broad ecological significance of reduced plant signaling effectiveness, few studies have examined behavioral responses of insects to their hosts in polluted environments. Here, we use a laboratory study to test the effect of ozone concentration gradients on the ability of the striped cucumber beetle (Acalymma vittatum) to locate flowers of its host plant, Cucurbita foetidissima. Y-tube experiments showed that ozone mixing ratios below 80 parts per billion (ppb) resulted in beetles moving toward their host plant, but levels above 80 ppb resulted in beetles moving randomly with respect to host location. There was no evidence that beetles avoided polluted air directly. The results show that ozone pollution has great potential to perniciously alter key interactions between plants and animals. (letter)

  18. Ozone impedes the ability of a herbivore to find its host

    Science.gov (United States)

    Fuentes, Jose D.; Roulston, T.'ai H.; Zenker, John

    2013-03-01

    Plant-emitted hydrocarbons mediate several key interactions between plants and insects. They enhance the ability of pollinators and herbivores to locate suitable host plants, and parasitoids to locate herbivores. While plant volatiles provide strong chemical signals, these signals are potentially degraded by exposure to pollutants such as ozone, which has increased in the troposphere and is projected to continue to increase over the coming decades. Despite the potential broad ecological significance of reduced plant signaling effectiveness, few studies have examined behavioral responses of insects to their hosts in polluted environments. Here, we use a laboratory study to test the effect of ozone concentration gradients on the ability of the striped cucumber beetle (Acalymma vittatum) to locate flowers of its host plant, Cucurbita foetidissima. Y-tube experiments showed that ozone mixing ratios below 80 parts per billion (ppb) resulted in beetles moving toward their host plant, but levels above 80 ppb resulted in beetles moving randomly with respect to host location. There was no evidence that beetles avoided polluted air directly. The results show that ozone pollution has great potential to perniciously alter key interactions between plants and animals.

  19. A Global Ozone Climatology from Ozone Soundings via Trajectory Mapping: A Stratospheric Perspective

    Science.gov (United States)

    Liu, J. J.; Tarasick, D. W.; Fioletov, V. E.; McLinden, C.; Zhao, T.; Gong, S.; Sioris, G.; Jin, J. J.; Liu, G.; Moeini, O.

    2013-01-01

    as the spring ozone maximum over the Canadian Arctic. It also covers higher latitudes than current satellite data. The climatology shows clearly the depletion of ozone from the 1970s to the mid 1990s and ozone recovery in the 2000s. When this climatology is used as the upper boundary condition in an Environment Canada operational chemical forecast model, the forecast is improved in the vicinity of the upper tropospherelower stratosphere region. As this ozone climatology is neither dependent on a priori data or photochemical modeling, it provides independent information and insight that can supplement satellite data and model simulations and enhance our understanding of stratospheric ozone.

  20. New Directions: Ozone-initiated reaction products indoors may be more harmful than ozone itself

    Science.gov (United States)

    Weschler, Charles J.

    2004-10-01

    Epidemiological studies have found associations between ozone concentrations measured at outdoor monitoring stations and certain adverse health outcomes. As a recent example, Gent et al. (2003, Journal of the American Medical Association 290, 1859-1867) have observed an association between ozone levels and respiratory symptoms as well as the use of maintenance medication by 271 asthmatic children living in Connecticut and the Springfield area of Massachusetts. In another example, Gilliland et al. (2001, Epidemiology 12, 43-54) detected an association between short-term increases in ozone levels and increased absences among 4th grade students from 12 southern California communities during the period from January to June 1996. Although children may spend a significant amount of time outdoors, especially during periods when ozone levels are elevated, they spend a much larger fraction of their time indoors. I hypothesize that exposure to the products of ozone-initiated indoor chemistry is more directly responsible for the health effects observed in the cited epidemiological studies than is exposure to outdoor ozone itself.

  1. Ozone therapy in periodontics.

    Science.gov (United States)

    Gupta, G; Mansi, B

    2012-02-22

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics.

  2. Ozone distribution in remote ecologically vulnerable terrain of the southern Sierra Nevada, CA

    International Nuclear Information System (INIS)

    Panek, Jeanne; Saah, David; Esperanza, Annie; Bytnerowicz, Andrzej; Fraczek, Witold; Cisneros, Ricardo

    2013-01-01

    Ozone concentration spatial patterns remain largely uncharacterized across the extensive wilderness areas of the Sierra Nevada, CA, despite being downwind of major pollution sources. These natural areas, including four national parks and four national forests, contain forest species that are susceptible to ozone injury. Forests stressed by ozone are also more vulnerable to other agents of mortality, including insects, pathogens, climate change, and ultimately fire. Here we analyze three years of passive ozone monitor data from the southern Sierra Nevada and interpolate landscape-scale spatial and temporal patterns during the summer-through-fall high ozone concentration period. Segmentation analysis revealed three types of ozone exposure sub-regions: high, low, and variable. Consistently high ozone exposure regions are expected to be most vulnerable to forest mortality. One high exposure sub-region has been documented elsewhere as being further vulnerable to increased drought and fire potential. Identifying such hot-spots of forest vulnerability has utility for prioritizing management. -- Highlights: •Three years of passive ozone sampler data over 49,000 km 2 were analyzed spatially. •Spatial and temporal ozone patterns were mapped across the Sierra Nevada, CA. •Sub-regions of consistently high, low and variable ozone exposure were identified. •The 1700–2400 m elevation band delineated a distinct break in ozone concentration. •This approach has utility for prioritizing management across vulnerable landscapes. -- A passive ozone sampler network in combination with spatial analysis techniques was used to characterize landscape-scale ozone patterns and dynamics, identifying regions of consistently high and low ozone exposure for forest management prioritization

  3. Reuse of sewage sludge as a catalyst in ozonation – Efficiency for the removal of oxalic acid and the control of bromate formation

    International Nuclear Information System (INIS)

    Wen, Gang; Pan, Zhi-Hui; Ma, Jun; Liu, Zheng-Qian; Zhao, Lei; Li, Jun-Jing

    2012-01-01

    Highlights: ► Sewage sludge was converted into catalyst (SBC) and characterized. ► SBC can enhance oxalic acid degradation in ozonation. ► Surface reaction mechanism is responsible for enhancement of ozonation by SBC. ► SBC can control the formation of bromate in ozonation. ► Several combined reasons for the control of bromate formation are proposed. - Abstract: Sewage derived sludge is produced with an annual amount increase of 2% all over the world and it is an urgent issue to be addressed by human being. In the present study, sludge was converted into sludge-based catalyst (SBC) with ZnCl 2 as activation agent and characterized by several methods (e.g., scanning electron microscope, X-ray photoelectron spectroscope and Fourier transform infrared spectroscope). Then it was used as a catalyst to enhance the removal of refractory organic matter, oxalic acid, and to control the formation of bromate (BrO 3 − ) in bench semi-continuous ozonation experiments. The effects of various operating parameters on the control of BrO 3 − formation were investigated. Furthermore, the mechanism for the enhancement of organic matter removal and the control of BrO 3 − formation was discussed as well. Results indicate that the combination of SBC with ozone shows a strong synergistic effect, resulting in a notable improvement on oxalic acid removal. A crucial surface reaction mechanism for the enhancement of organic matter removal is proposed on the basis of negative effect of higher pH and no inhibition effect of tert-butanol. The control for BrO 3 − formation was demonstrated and the reason for its control in the process of O 3 /SBC is the combined effect of SBC reductive properties, ozone exposure decrease and hydrogen peroxide concentration increase.

  4. Induction of enhanced acoustic startle response by noise exposure: dependence on exposure conditions and testing parameters and possible relevance to hyperacusis.

    Directory of Open Access Journals (Sweden)

    Rony H Salloum

    Full Text Available There has been a recent surge of interest in the development of animal models of hyperacusis, a condition in which tolerance to sounds of moderate and high intensities is diminished. The reasons for this decreased tolerance are likely multifactorial, but some major factors that contribute to hyperacusis are increased loudness perception and heightened sensitivity and/or responsiveness to sound. Increased sound sensitivity is a symptom that sometimes develops in human subjects after acoustic insult and has recently been demonstrated in animals as evidenced by enhancement of the acoustic startle reflex following acoustic over-exposure. However, different laboratories have obtained conflicting results in this regard, with some studies reporting enhanced startle, others reporting weakened startle, and still others reporting little, if any, change in the amplitude of the acoustic startle reflex following noise exposure. In an effort to gain insight into these discrepancies, we conducted measures of acoustic startle responses (ASR in animals exposed to different levels of sound, and repeated such measures on consecutive days using a range of different startle stimuli. Since many studies combine measures of acoustic startle with measures of gap detection, we also tested ASR in two different acoustic contexts, one in which the startle amplitudes were tested in isolation, the other in which startle amplitudes were measured in the context of the gap detection test. The results reveal that the emergence of chronic hyperacusis-like enhancements of startle following noise exposure is highly reproducible but is dependent on the post-exposure thresholds, the time when the measures are performed and the context in which the ASR measures are obtained. These findings could explain many of the discrepancies that exist across studies and suggest guidelines for inducing in animals enhancements of the startle reflex that may be related to hyperacusis.

  5. Foreign and Domestic Contributions to Springtime Ozone Pollution over China

    Science.gov (United States)

    Ni, R.; Lin, J.; Yan, Y.; Lin, W.; Chen, H.

    2017-12-01

    Ozone is a critical air pollutant that damages human health and vegetation. Previous studies for the United States and Europe have shown large influences of foreign emissions on domestic ozone levels, whereas the relative contributions of foreign versus domestic emissions are much less clear for China. Here, we use a global-regional two-way coupled model system based on GEOS-Chem to quantify the contributions to springtime ozone over China from anthropogenic emissions in major source regions across the globe. Our results indicate considerable influences of foreign anthropogenic pollution on China's ozone pollution. Together, foreign anthropogenic emissions enhance springtime surface ozone over China by 3 12 ppb. Of all ozone over China produced by global anthropogenic emissions, foreign emissions contribute 40% near the surface, and the contribution increases with altitude until a value of 80% in the upper troposphere. Impact from Japan and Korea is 1 2 ppb over east coastal regions, and negligible in inland. Anthropogenic emissions of South and South-East Asia increase ozone over Tibet and the Yunnan-Guizhou Plateau by up to 5 ppb, and their contribution increases with height due to strong vertical transport. Pollution from North America and Europe mainly accompanies strong westerly winds and frequent cyclonic activities that are favorable to long-range transport. European anthropogenic pollution enhances surface ozone by 1 3 ppb over West and North China. Despite a much longer transport distance, the contribution from North America is greater than European contribution due to the nearly doubled amount of anthropogenic NMVOC emissions. The high percentage contribution of foreign anthropogenic emissions to China's ozone pollution can be partly explained by excessive domestic NOx emissions that suppress ozone production efficiency and even destroy ozone. Our study is relevant to Chinese ozone pollution control and global environmental protection collaboration.

  6. Short-term exposure to oleandrin enhances responses to IL-8 by increasing cell surface IL-8 receptors

    Science.gov (United States)

    Raviprakash, Nune; Manna, Sunil Kumar

    2014-01-01

    BACKGROUND AND PURPOSE One of the first steps in host defence is the migration of leukocytes. IL-8 and its receptors are a chemokine system essential to such migration. Up-regulation of these receptors would be a viable strategy to treat dysfunctional host defence. Here, we studied the effects of the plant glycoside oleandrin on responses to IL-8 in a human monocytic cell line. EXPERIMENTAL APPROACH U937 cells were incubated with oleandrin (1-200 ng mL−1) for either 1 h (pulse) or for 24 h (non-pulse). Apoptosis; activation of NF-κB, AP-1 and NFAT; calcineurin activity and IL-8 receptors (CXCR1 and CXCR2) were measured using Western blotting, RT-PCR and reporter gene assays. KEY RESULTS Pulse exposure to oleandrin did not induce apoptosis or cytoxicity as observed after non-pulse exposure. Pulse exposure enhanced activation of NF-κB induced by IL-8 but not that induced by TNF-α, IL-1, EGF or LPS. Exposure to other apoptosis-inducing compounds (azadirachtin, resveratrol, thiadiazolidine, or benzofuran) did not enhance activation of NF-κB. Pulse exposure to oleandrin increased expression of IL-8 receptors and chemotaxis, release of enzymes and activation of NF-κB, NFAT and AP-1 along with increased IL-8-mediated calcineurin activation, and wound healing. Pulse exposure increased numbers of cell surface IL-8 receptors. CONCLUSIONS AND IMPLICATIONS Short-term (1 h; pulse) exposure to a toxic glycoside oleandrin, enhanced biological responses to IL-8 in monocytic cells, without cytoxicity. Pulse exposure to oleandrin could provide a viable therapy for those conditions where leukocyte migration is defective. PMID:24172227

  7. SMM mesospheric ozone measurements

    Science.gov (United States)

    Aikin, A. C.

    1990-01-01

    The main objective was to understand the secular and seasonal behavior of ozone in the lower mesosphere, 50 to 70 km. This altitude region is important in understanding the factors which determine ozone behavior. A secondary objective is the study of stratospheric ozone in the polar regions. Use is made of results from the SBUV satellite borne instrument. In the Arctic the interaction between chlorine compounds and low molecular weight hydrocarbons is studied. More than 30,000 profiles were obtained using the UVSP instrument on the SMM spacecraft. Several orbits of ozone data per day were obtained allowing study of the current rise in solar activity from the minimum until the present. Analysis of Nimbus 7 SBUV data in Antarctic spring indicates that ozone is depleted within the polar vortex relative to ozone outside the vortex. This depletion confirms the picture of ozone loss at altitudes where polar stratospheric clouds exist. In addition, there is ozone loss above the cloud level indicating that there is another mechanism in addition to ozone loss initiated by heterogeneous chlorine reactions on cloud particles.

  8. Enhancement of natural radiation and population exposures due to the activity of large steelworks

    Energy Technology Data Exchange (ETDEWEB)

    Niewiadomski, T; Godek, J; Jasinska, M; Wasiolek, P [Institute of Nuclear Physics, Krakow (Poland)

    1984-09-01

    Radionuclide releases and resulting population exposures from large industrial plants have recently become a subject of some public concern. Methods for assessing these effects were developed and, as an example, a complex of large steelworks located in the vicinity of the city of Krakow was investigated. The following critical pathways were considered: atmospheric release, and use of fly ash for production of building materials. For assessing annual average radionuclide concentrations in air and in soil around the works, a computer program was developed while other mathematical methods were applied to the assessment of maximum individual effective dose equivalent commitments (EDEC) due to inhalation, ingestion, and external gamma radiation. In order to acquire data for calculations many samples of raw materials, coal, ash, and dust were analysed as to their radionuclide concentration. The total individual EDEC at the place of maximum immission was estimated to be about 100 ..mu..Sv a/sup -1/ (i.e., about 6% of the natural exposure in this region), this being mainly due to ingestion (ca. 65 ..mu..Sv a/sup -1/) and to gamma radiation (ca. 30 ..mu..Sv a/sup -1/). The enhancement of dose rates over the ponds and of radioactivity concentration of liquid discharges from the ponds was found to be negligible. Dose rates in houses built entirely of fly ash were estimated to be higher than those in red-brick houses by not more than 0.2 ..mu..Sv a/sup -1/. The collective EDEC from the operational discharge of the steelworks is less than 11 man Sv a/sup -1/ and that of use of fly-ash prefabricated elements will be in the future less than 45 man Sv a/sup -1/.

  9. Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example

    Energy Technology Data Exchange (ETDEWEB)

    Paoletti, Elena [Institut Plant Protection (IPP), National Council Research (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy)], E-mail: e.paoletti@ipp.cnr.it; Ferrara, Anna Maria [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Calatayud, Vicent; Cervero, Julia [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Giannetti, Fabio [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Sanz, Maria Jose [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States)

    2009-03-15

    Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300 ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30 ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation. - An Italian population of the deciduous shrub Hibiscus syriacus, a common ornamental species in temperate zones, is recommended as ozone bioindicator.

  10. Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example

    International Nuclear Information System (INIS)

    Paoletti, Elena; Ferrara, Anna Maria; Calatayud, Vicent; Cervero, Julia; Giannetti, Fabio; Sanz, Maria Jose; Manning, William J.

    2009-01-01

    Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300 ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30 ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation. - An Italian population of the deciduous shrub Hibiscus syriacus, a common ornamental species in temperate zones, is recommended as ozone bioindicator

  11. Thermoluminescence as a tool for monitoring ozone-stressed plants

    Energy Technology Data Exchange (ETDEWEB)

    Skotnica, J.; Gilbert, M.; Weingart, I.; Wilhelm, C

    2003-05-01

    Thermoluminescence parameters are more sensitive to ozone than fluorescence parameters (F{sub 0}, F{sub M}, F{sub v}/F{sub M}). - The effect of ozone (6 h, various concentrations from 0 to 350 ppb) on barley (Hordeum vulgare L., cv. Bomi) and tomato (Lycopersicon esculentum L., cv. Yellow Cherry) leaves was investigated in parallel by thermoluminescence (TL) and fluorescence (FL) methods. Several significant changes were found in TL glow curves measured after excitation by one single turnover flash at +2 deg. C in the temperature range from 2 to 170 deg. C immediately after ozone exposure. Contrary to TL, ozone induced only negligible changes in FL parameters F{sub 0}, F{sub M} and F{sub v}/F{sub M}. Measurements done 24 h after ozone exposure showed partial recovery of ozone-induced changes. The extent of recovery was not the same in different parts of TL curves. Fluorescence parameters were not significantly changed. The results demonstrate that TL parameters are more sensitive to ozone than conventially used FL parameters F{sub 0}, F{sub M} and F{sub v}/F{sub M}. Moreover, TL measurements seem to give information not only about the PSII electron transport, but also about the extent of oxidative damage and membrane lipid peroxidation. It is concluded, that TL can be a highly informative tool for monitoring the impact of ozone on plants.

  12. Modulations of stratospheric ozone by volcanic eruptions

    Science.gov (United States)

    Blanchette, Christian; Mcconnell, John C.

    1994-01-01

    We have used a time series of aerosol surface based on the measurements of Hofmann to investigate the modulation of total column ozone caused by the perturbation to gas phase chemistry by the reaction N2O5(gas) + H2O(aero) yields 2HNO3(gas) on the surface of stratospheric aerosols. We have tested a range of values for its reaction probability, gamma = 0.02, 0.13, and 0.26 which we compared to unperturbed homogeneous chemistry. Our analysis spans a period from Jan. 1974 to Oct. 1994. The results suggest that if lower values of gamma are the norm then we would expect larger ozone losses for highly enhanced aerosol content that for larger values of gamma. The ozone layer is more sensitive to the magnitude of the reaction probability under background conditions than during volcanically active periods. For most conditions, the conversion of NO2 to HNO3 is saturated for reaction probability in the range of laboratory measurements, but is only absolutely saturated following major volcanic eruptions when the heterogeneous loss dominates the losses of N2O5. The ozone loss due to this heterogeneous reaction increases with the increasing chlorine load. Total ozone losses calculated are comparable to ozone losses reported from TOMS and Dobson data.

  13. Ozone decomposition kinetics on alumina: effects of ozone partial pressure, relative humidity and repeated oxidation cycles

    Directory of Open Access Journals (Sweden)

    R. C. Sullivan

    2004-01-01

    Full Text Available The room temperature kinetics of gas-phase ozone loss via heterogeneous interactions with thin alumina films has been studied in real-time using 254nm absorption spectroscopy to monitor ozone concentrations. The films were prepared from dispersions of fine alumina powder in methanol and their surface areas were determined by an in situ procedure using adsorption of krypton at 77K. The alumina was found to lose reactivity with increasing ozone exposure. However, some of the lost reactivity could be recovered over timescales of days in an environment free of water, ozone and carbon dioxide. From multiple exposures of ozone to the same film, it was found that the number of active sites is large, greater than 1.4x1014 active sites per cm2 of surface area or comparable to the total number of surface sites. The films maintain some reactivity at this point, which is consistent with there being some degree of active site regeneration during the experiment and with ozone loss being catalytic to some degree. The initial uptake coefficients on fresh films were found to be inversely dependent on the ozone concentration, varying from roughly 10-6 for ozone concentrations of 1014 molecules/cm3 to 10-5 at 1013 molecules/cm3. The initial uptake coefficients were not dependent on the relative humidity, up to 75%, within the precision of the experiment. The reaction mechanism is discussed, as well as the implications these results have for assessing the effect of mineral dust on atmospheric oxidant levels.

  14. Ozone co-exposure modifies cardiac responses to fine and ultrafine ambient particulate matter in mice: concordance of electrocardiogram and mechanical responses

    Science.gov (United States)

    BackgroundStudies have shown a relationship between air pollution and increased risk of cardiovascular morbidity and mortality. Due to the complexity of ambient air pollution composition, recent studies have examined the effects of co-exposure, particularly particulate matter (PM...

  15. Efficient catalytic ozonation by ruthenium nanoparticles supported on SiO2 or TiO2: Towards the use of a non-woven fiber paper as original support

    KAUST Repository

    Biard, Pierre-François

    2015-12-24

    This work focuses on the use of Ru(0) nanoparticles as heterogeneous catalyst for ozone decomposition and radical production. In a first set of experiments, the nanoparticles have been deposited on two inorganic supports (TiO2 or SiO2) by a wet impregnation approach. This study confirmed the high potential of Ru nanoparticles as active species for ozone decomposition at pH 3, since the ozone half-life time decreases by a factor 20-25, compared to the reference experiment carried out without any catalyst. The enhancement of the ozone decomposition kinetics provided an improved radical production and a higher transient radical concentration in a shorten ozone exposure. Consequently, lower oxidant dosage and contact time would be necessary. Thus, very significant atrazine consumption kinetics enhancements were measured. In a second set of experiments, a non-woven fiber paper composed of a TiO2/SiO2/zeolite mixture has been evaluated as an original support for ruthenium nanoparticles. Even if lower ozone decomposition kinetics was observed compared to TiO2 or SiO2, this support would be a promising alternative to inorganic powders to avoid the catalyst recovery step and to design reactors such as tubular reactors. A new numerical procedure is presented for the evaluation of the transient HO° concentration and of the Rct.

  16. The Ecophysiology Of A Pinus Ponderosa Ecosystem Exposed To High Tropospheric Ozone: Implications For Stomatal And Non-Stomatal Ozone Fluxes

    Science.gov (United States)

    Fares, S.; McKay, M.; Goldstein, A.

    2008-12-01

    Ecosystems remove ozone from the troposphere through both stomatal and non-stomatal deposition. The portion of ozone taken up through stomata has an oxidative effect causing damage. We used a multi-year dataset to assess the physiological controls over ozone deposition. Environmental parameters, CO2 and ozone fluxes were measured continuously from January 2001 to December 2006 above a ponderosa pine plantation near Blodgett Forest, Georgetown, California. We studied the dynamic of NEE (Net Ecosystem Exchange, -838 g C m-2 yr-1) and water evapotranspiration on an annual and daily basis. These processes are tightly coupled to stomatal aperture which also controlled ozone fluxes. High levels of ozone concentrations (~ 100 ppb) were observed during the spring-summer period, with corresponding high levels of ozone fluxes (~ 30 μmol m-2 h-1). During the summer season, a large portion of the total ozone flux was due to non-stomatal processes, and we propose that a plant physiological control, releasing BVOC (Biogenic Volatile Organic Compounds), is mainly responsible. We analyzed the correlations of common ozone exposure metrics based on accumulation of concentrations (AOT40 and SUM0) with ozone fluxes (total, stomatal and non-stomatal). Stomatal flux showed poorer correlation with ozone concentrations than non-stomatal flux during summer and fall seasons, which largely corresponded to the growing period. We therefore suggest that AOT40 and SUM0 are poor predictors of ozone damage and that a physiologically based metric would be more effective.

  17. Ultraviolet-B- and ozone-induced biochemical changes in antioxidant enzymes of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Rao, M.V.; Paliyath, G.; Ormrod, D.P.

    1996-01-01

    Earlier studies with Arabidopsis thaliana exposed to ultraviolet B (UV-B) and ozone (O 3 ) have indicated the differential responses of superoxide dismutase and glutathione reductase. In this study, we have investigated whether A. thaliana genotype Landsberg erecta and its flavonoid-deficient mutant transparent testa (tt5) is capable of metabolizing UV-B- and O 3 -induced activated oxygen species by invoking similar antioxidant enzymes. UV-B exposure preferentially enhanced guaiacol-peroxidases, ascorbate peroxidase, and peroxidases specific to coniferyl alcohol and modified the substrate affinity of ascorbate peroxidase. O 3 exposure enhanced superoxide dismutase, peroxidases, glutathione reductase, and ascorbate peroxidase to a similar degree and modified the substrate affinity of both glutathione reductase and ascorbate peroxidase. Both UV-B and O 3 exposure enhanced similar Cu,Zn-superoxide dismutase isoforms. New isoforms of peroxidases and ascorbate peroxidase were synthesized in tt5 plants irradiated with UV-B. UV-B radiation, in contrast to O 3 , enhanced the activation oxygen species by increasing membrane-localized NADPH-oxidase activity and decreasing catalase activities. These results collectively suggest that (a) UV-B exposure preferentially induces peroxidase-related enzymes, whereas O 3 exposure invokes the enzymes of superoxide dismutase/ascorbate-glutathione cycle, and (b) in contrast to O 3 , UV-B exposure generated activated oxygen species by increasing NADPH-oxidase activity. 10 figs., 4 tabs

  18. A Critical Test of Self-Enhancement, Exposure, and Self-Categorization Explanations for First- and Third-Person Perceptions

    Science.gov (United States)

    Reid, Scott A.; Byrne, Sahara; Brundidge, Jennifer S.; Shoham, Mirit D.; Marlow, Mikaela L.

    2007-01-01

    The third-person perception is the tendency for people to believe that others are more influenced by media content than themselves (W. P. Davison, 1983). The current study provides a critical test of self-enhancement, exposure, and self-categorization explanations for first- (i.e., self more influenced than others) and third-person perceptions.…

  19. Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    J. W. Greenslade

    2017-09-01

    Full Text Available Stratosphere-to-troposphere transport (STT provides an important natural source of ozone to the upper troposphere, but the characteristics of STT events in the Southern Hemisphere extratropics and their contribution to the regional tropospheric ozone budget remain poorly constrained. Here, we develop a quantitative method to identify STT events from ozonesonde profiles. Using this method we estimate the seasonality of STT events and quantify the ozone transported across the tropopause over Davis (69° S, 2006–2013, Macquarie Island (54° S, 2004–2013, and Melbourne (38° S, 2004–2013. STT seasonality is determined by two distinct methods: a Fourier bandpass filter of the vertical ozone profile and an analysis of the Brunt–Väisälä frequency. Using a bandpass filter on 7–9 years of ozone profiles from each site provides clear detection of STT events, with maximum occurrences during summer and minimum during winter for all three sites. The majority of tropospheric ozone enhancements owing to STT events occur within 2.5 and 3 km of the tropopause at Davis and Macquarie Island respectively. Events are more spread out at Melbourne, occurring frequently up to 6 km from the tropopause. The mean fraction of total tropospheric ozone attributed to STT during STT events is  ∼ 1. 0–3. 5 % at each site; however, during individual events, over 10 % of tropospheric ozone may be directly transported from the stratosphere. The cause of STTs is determined to be largely due to synoptic low-pressure frontal systems, determined using coincident ERA-Interim reanalysis meteorological data. Ozone enhancements can also be caused by biomass burning plumes transported from Africa and South America, which are apparent during austral winter and spring and are determined using satellite measurements of CO. To provide regional context for the ozonesonde observations, we use the GEOS-Chem chemical transport model, which is too coarsely

  20. Soil bacterial consortia and previous exposure enhance the biodegradation of sulfonamides from pig manure.

    Science.gov (United States)

    Islas-Espinoza, Marina; Reid, Brian J; Wexler, Margaret; Bond, Philip L

    2012-07-01

    Persistence or degradation of synthetic antibiotics in soil is crucial in assessing their environmental risks. Microbial catabolic activity in a sandy loamy soil with pig manure using 12C- and 14C-labelled sulfamethazine (SMZ) respirometry showed that SMZ was not readily degradable. But after 100 days, degradation in sulfadiazine-exposed manure was 9.2%, far greater than soil and organic manure (0.5% and 0.11%, respectively, p library from the treatment with highest degradation showed that most bacteria belonged to α, β and γ classes of Proteobacteria, Firmicutes, Bacteroidetes and Acidobacteria. Proteobacteria (α, β and γ), Firmicutes and Bacteroidetes which were the most abundant classes on day 1 also decreased most following prolonged exposure. From the matrix showing the highest degradation rate, 17 SMZ-resistant isolates biodegraded low levels of 14C-labelled SMZ when each species was incubated separately (0.2-1.5%) but biodegradation was enhanced when the four isolates with the highest biodegradation were incubated in a consortium (Bacillus licheniformis, Pseudomonas putida, Alcaligenes sp. and Aquamicrobium defluvium as per 16S rRNA gene sequencing), removing up to 7.8% of SMZ after 20 days. One of these species (B. licheniformis) was a known livestock and occasional human pathogen. Despite an environmental role of these species in sulfonamide bioremediation, the possibility of horizontal transfer of pathogenicity and resistance genes should caution against an indiscriminate use of these species as sulfonamide degraders.

  1. Global Ozone Distribution relevant to Human Health: Metrics and present day levels from the Tropospheric Ozone Assessment Report (TOAR)

    Science.gov (United States)

    Fleming, Z. L.; Doherty, R. M.; von Schneidemesser, E.; Cooper, O. R.; Malley, C.; Colette, A.; Xu, X.; Pinto, J. P.; Simpson, D.; Schultz, M. G.; Hamad, S.; Moola, R.; Solberg, S.; Feng, Z.

    2017-12-01

    Using stations from the TOAR surface ozone database, this study quantifies present-day global and regional distributions of five ozone metrics relevant for both short-term and long-term human exposure. These metrics were explored at ozone monitoring sites globally, and re-classified for this project as urban or non-urban using population densities and night-time lights. National surface ozone limit values are usually related to an annual number of exceedances of daily maximum 8-hour running mean (MDA8), with many countries not even having any ozone limit values. A discussion and comparison of exceedances in the different ozone metrics, their locations and the seasonality of exceedances provides clues as to the regions that potentially have more serious ozone health implications. Present day ozone levels (2010-2014) have been compared globally and show definite geographical differences (see Figure showing the annual 4th highest MDA8 for present day ozone for all non-urban stations). Higher ozone levels are seen in western compared to eastern US, and between southern and northern Europe, and generally higher levels in east Asia. The metrics reflective of peak concentrations show highest values in western North America, southern Europe and East Asia. A number of the metrics show similar distributions of North-South gradients, most prominent across Europe and Japan. The interquartile range of the regional ozone metrics was largest in East Asia, higher for urban stations in Asia but higher for non-urban stations in Europe and North America. With over 3000 monitoring stations included in this analysis and despite the higher densities of monitoring stations in Europe, north America and East Asia, this study provides the most comprehensive global picture to date of surface ozone levels in terms of health-relevant metrics.

  2. Co-exposure to nickel and cobalt chloride enhances cytotoxicity and oxidative stress in human lung epithelial cells

    International Nuclear Information System (INIS)

    Patel, Eshan; Lynch, Christine; Ruff, Victoria; Reynolds, Mindy

    2012-01-01

    Nickel and cobalt are heavy metals found in land, water, and air that can enter the body primarily through the respiratory tract and accumulate to toxic levels. Nickel compounds are known to be carcinogenic to humans and animals, while cobalt compounds produce tumors in animals and are probably carcinogenic to humans. People working in industrial and manufacturing settings have an increased risk of exposure to these metals. The cytotoxicity of nickel and cobalt has individually been demonstrated; however, the underlying mechanisms of co-exposure to these heavy metals have not been explored. In this study, we investigated the effect of exposure of H460 human lung epithelial cells to nickel and cobalt, both alone and in combination, on cell survival, apoptotic mechanisms, and the generation of reactive oxygen species and double strand breaks. For simultaneous exposure, cells were exposed to a constant dose of 150 μM cobalt or nickel, which was found to be relatively nontoxic in single exposure experiments. We demonstrated that cells exposed simultaneously to cobalt and nickel exhibit a dose-dependent decrease in survival compared to the cells exposed to a single metal. The decrease in survival was the result of enhanced caspase 3 and 7 activation and cleavage of poly (ADP-ribose) polymerase. Co-exposure increased the production of ROS and the formation of double strand breaks. Pretreatment with N-acetyl cysteine alleviated the toxic responses. Collectively, this study demonstrates that co-exposure to cobalt and nickel is significantly more toxic than single exposure and that toxicity is related to the formation of ROS and DSB. -- Highlights: ► Decreased survival following simultaneous exposure to NiCl 2 and CoCl 2 . ► Enhanced caspase and PARP cleavage following co-exposure. ► Increased formation of ROS in dual exposed cells. ► N-acetyl cysteine pretreatment decreases Co and Ni toxicity. ► Co-exposure to Ni and Co enhances the formation of double strand

  3. Factors affecting ozone removal rates in a simulated aircraft cabin environment

    DEFF Research Database (Denmark)

    Tamas, Gyöngyi; Weschler, Charles J.; Bako-Biro, Zsolt

    2006-01-01

    of people, soiled T-shirts, aircraft seats and a used HEPA filter, we have been able in the course of 24 experiments to isolate the contributions of these and other factors to the removal of ozone from the cabin air. In the case of this simulated aircraft, people were responsible for almost 60% of the ozone...... present, the measured ratio of ozone's concentration in the cabin versus that outside the cabin was 0.15-0.21, smaller than levels reported in the literature. The results reinforce the conclusion that the optimal way to reduce people's exposure to both ozone and ozone oxidation products is to efficiently...

  4. Mass spectrometric investigation of the isotopes of ozone in the laboratory and the stratosphere

    International Nuclear Information System (INIS)

    Mauersberger, K.; Morton, J.; Schueler, B.

    1991-01-01

    During the last few years information on the isotope anomalies of ozone has substantially increased. Whenever ozone is formed in a gas phase reaction, an enhancement in its heavy isotopes is found of magnitude 12-14% ( 50 O 3 ) above the statistically expected values. The mass-independent enhancement decreases toward higher pressures and also shows a pronounced temperature dependence. Toward lower temperatures the enhancement becomes less. Studies of all possible ozone isotopes have shown that molecular symmetry plays a major role. Even large enhancements, above the laboratory results, have been occasionally measured in the stratosphere using a number of different experimental techniques. A correlation between very high heavy ozone enhancement (> 30%) and high solar activity may exist. The behavior of ozone isotopes will provide information about the ozone formation process

  5. Pollution Control Using Ozone

    DEFF Research Database (Denmark)

    2017-01-01

    This invention relates to a method for cleaning air comprising one or more pollutants, the method comprising contacting the air with thermal decompositions products of ozone.......This invention relates to a method for cleaning air comprising one or more pollutants, the method comprising contacting the air with thermal decompositions products of ozone....

  6. The pollution by ozone

    International Nuclear Information System (INIS)

    1997-09-01

    Air pollution by ozone is increasing in spite of several points to reduce it. If the process of ozone formation are complex, the sources of this pollution are well known: first, mobile sources with automobiles (49%), boats , trains and planes (13%), then are following paints and solvents(18%), thermal power plants(11%), and finally industry processing with 5%. (N.C.)

  7. Observations of ozone formation in power plant plumes and implications for ozone control strategies

    Energy Technology Data Exchange (ETDEWEB)

    Ryerson, T.B.; Trainer, M.; Holloway, J.S.; Parrish, D.D.; Huey, L.G.; Sueper, D.T.; Frost, G.J.; Donnelly, S.G.; Schauffler, S.; Atlas, E.L.; Kuster, W.C.; Goldan, P.D.; Huebler, G.; Meagher, J.F.; Fehsenfeld, F.C. [NOAA, Boulder, CO (USA). Aeronomy Lab.

    2001-04-27

    Data taken in aircraft transects of emissions plumes from rural US coal-fired power plants were used to confirm and quantify the nonlinear dependence of tropospheric ozone formation on plume NOx (NO plus NO{sub 2}) concentration, which is determined by plant NOx emission rate and atmospheric dispersion. The ambient availability of reactive volatile organic compounds, principally biogenic isoprene, was also found to modular ozone production rate and yield in these rural plumes. Differences of a factor of 2 or greater in plume ozone formation rates and yields as a function of NOx and volatile organic compound concentrations were consistently observed. These large differences suggest that consideration of power plant NOx emission rates and geographic locations in current and future US ozone control strategies could substantially enhance the efficacy of NOx reductions from these sources. 18 refs., 4 figs.

  8. Forests and ozone: productivity, carbon storage, and feedbacks.

    Science.gov (United States)

    Wang, Bin; Shugart, Herman H; Shuman, Jacquelyn K; Lerdau, Manuel T

    2016-02-22

    Tropospheric ozone is a serious air-pollutant, with large impacts on plant function. This study demonstrates that tropospheric ozone, although it damages plant metabolism, does not necessarily reduce ecosystem processes such as productivity or carbon sequestration because of diversity change and compensatory processes at the community scale ameliorate negative impacts at the individual level. This study assesses the impact of ozone on forest composition and ecosystem dynamics with an individual-based gap model that includes basic physiology as well as species-specific metabolic properties. Elevated tropospheric ozone leads to no reduction of forest productivity and carbon stock and to increased isoprene emissions, which result from enhanced dominance by isoprene-emitting species (which tolerate ozone stress better than non-emitters). This study suggests that tropospheric ozone may not diminish forest carbon sequestration capacity. This study also suggests that, because of the often positive relationship between isoprene emission and ozone formation, there is a positive feedback loop between forest communities and ozone, which further aggravates ozone pollution.

  9. Spatio-temporal observations of the tertiary ozone maximum

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2009-07-01

    Full Text Available We present spatio-temporal distributions of the tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  10. Nicotiana tabacum as model for ozone - plant surface reactions

    Science.gov (United States)

    Jud, Werner; Fischer, Lukas; Wohlfahrt, Georg; Tissier, Alain; Canaval, Eva; Hansel, Armin

    2015-04-01

    Elevated tropospheric ozone concentrations are considered a toxic threat to plants, responsible for global crop losses with associated economic costs of several billion dollars per year. The ensuing injuries have been related to the uptake of ozone through the stomatal pores and oxidative effects damaging the internal leaf tissue. A striking question of current research is the environment and plant specific partitioning of ozone loss between gas phase, stomatal or plant surface sink terms. Here we show results from ozone fumigation experiments using various Nicotiana Tabacum varieties, whose surfaces are covered with different amounts of unsaturated diterpenoids exuded by their glandular trichomes. Exposure to elevated ozone levels (50 to 150 ppbv) for 5 to 15 hours in an exceptionally clean cuvette system did neither result in a reduction of photosynthesis nor caused any visible leaf damage. Both these ozone induced stress effects have been observed previously in ozone fumigation experiments with the ozone sensitive tobacco line Bel-W3. In our case ozone fumigation was accompanied by a continuous release of oxygenated volatile organic compounds, which could be clearly associated to their condensed phase precursors for the first time. Gas phase reactions of ozone were avoided by choosing a high enough gas exchange rate of the plant cuvette system. In the case of the Ambalema variety, that is known to exude only the diterpenoid cis-abienol, ozone fumigation experiments yield the volatiles formaldehyde and methyl vinyl ketone (MVK). The latter could be unequivocally separated from isomeric methacrolein (MACR) by the aid of a Selective Reagent Ion Time-of-Flight Mass Spectrometer (SRI-ToF-MS), which was switched every six minutes from H3O+ to NO+ primary ion mode and vice versa. Consistent with the picture of an ozone protection mechanism caused by reactive diterpenoids at the leaf surface are the results from dark-light experiments. The ozone loss obtained from the

  11. Estonian total ozone climatology

    Directory of Open Access Journals (Sweden)

    K. Eerme

    Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

  12. Relative impacts of worldwide tropospheric ozone changes and regional emission modifications on European surface-ozone levels

    International Nuclear Information System (INIS)

    Szopa, S.; Hauglustaine, D.A.

    2007-01-01

    Multi-scale models were applied to assess the surface ozone changes in 2030. Several emission scenarios are considered, ranging from (a) a pessimistic anthropogenic emission increase to (b) an optimistic decrease of emissions, and including (c) a realistic scenario that assumes the implementation of control legislations [CLE]. The two extreme scenarios lead respectively to homogeneous global increase and decrease of surface ozone, whereas low and inhomogeneous changes associated with a slight global increase of ozone are found for the CLE scenario. Over western Europe, for the CLE scenario, the benefit of European emission reduction is significantly counterbalanced by increasing global ozone levels. Considering warmer conditions over Europe and future emission modifications, the human health exposure to surface ozone is found to be significantly worsened. (authors)

  13. Ozone as an air pollutant

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    1996-01-01

    A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995.......A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995....

  14. On the link between martian total ozone and potential vorticity

    Science.gov (United States)

    Holmes, James A.; Lewis, Stephen R.; Patel, Manish R.

    2017-01-01

    We demonstrate for the first time that total ozone in the martian atmosphere is highly correlated with the dynamical tracer, potential vorticity, under certain conditions. The degree of correlation is investigated using a Mars global circulation model including a photochemical model. Potential vorticity is the quantity of choice to explore the dynamical nature of polar vortices because it contains information on winds and temperature in a single scalar variable. The correlation is found to display a distinct seasonal variation, with a strong positive correlation in both northern and southern winter at poleward latitudes in the northern and southern hemisphere respectively. The identified strong correlation implies variations in polar total ozone during winter are predominantly controlled by dynamical processes in these spatio-temporal regions. The weak correlation in northern and southern summer is due to the dominance of photochemical reactions resulting from extended exposure to sunlight. The total ozone/potential vorticity correlation is slightly weaker in southern winter due to topographical variations and the preference for ozone to accumulate in Hellas basin. In northern winter, total ozone can be used to track the polar vortex edge. The ozone/potential vorticity ratio is calculated for both northern and southern winter on Mars for the first time. Using the strong correlation in total ozone and potential vorticity in northern winter inside the polar vortex, it is shown that potential vorticity can be used as a proxy to deduce the distribution of total ozone where satellites cannot observe for the majority of northern winter. Where total ozone observations are available on the fringes of northern winter at poleward latitudes, the strong relationship of total ozone and potential vorticity implies that total ozone anomalies in the surf zone of the northern polar vortex can potentially be used to determine the origin of potential vorticity filaments.

  15. Ozone pollution affects flower numbers and timing in a simulated BAP priority calcareous grassland community

    International Nuclear Information System (INIS)

    Hayes, Felicity; Williamson, Jennifer; Mills, Gina

    2012-01-01

    Mesocosms representing the BAP Priority habitat ‘Calcareous Grassland’ were exposed to eight ozone profiles for twelve-weeks in two consecutive years. Half of the mesocosms received a reduced watering regime during the exposure periods. Numbers and timing of flowering in the second exposure period were related to ozone concentration and phytotoxic ozone dose (accumulated stomatal flux). For Lotus corniculatus, ozone accelerated the timing of the maximum number of flowers. An increase in mean ozone concentration from 30 ppb to 70 ppb corresponded with an advance in the timing of maximum flowering by six days. A significant reduction in flower numbers with increasing ozone was found for Campanula rotundifolia and Scabiosa columbaria and the relationship with ozone was stronger for those that were well-watered than for those with reduced watering. These changes in flowering timing and numbers could have large ecological impacts, affecting plant pollination and the food supply of nectar feeding insects. - Highlights: ► An increase in ozone accelerated timing of maximum flowering in Lotus corniculatus. ► Ozone reduced flower numbers in Campanula rotundifolia and Scabiosa columbaria. ► Reduced water availability did not protect most species from the effects of ozone. - Increased tropospheric ozone affected timing of flowering and maximum flower numbers in calcareous grassland mesocosms.

  16. Responses of Surface Ozone Air Quality to Anthropogenic Nitrogen Deposition

    Science.gov (United States)

    Zhang, L.; Zhao, Y.; Tai, A. P. K.; Chen, Y.; Pan, Y.

    2017-12-01

    Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth's surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface-atmosphere exchange. We combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by addition of atmospheric deposited nitrogen: emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a-1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index (LAI) in the model), could increase surface ozone from increased biogenic VOC emissions, but could also decrease ozone due to higher ozone dry deposition velocities. Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations show general increases over the globe (up to 1.5-2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5-1.0 ppbv decreases over the eastern US, Western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate and land use driven surface ozone changes at regional scales, and partly offset the surface ozone reductions due to land use changes reported in previous studies. Our study emphasizes the complexity of biosphere-atmosphere interactions, which can have important

  17. Ozone affects growth and development of Pieris brassicae on the wild host plant Brassica nigra

    International Nuclear Information System (INIS)

    Khaling, Eliezer; Papazian, Stefano; Poelman, Erik H.; Holopainen, Jarmo K.; Albrectsen, Benedicte R.; Blande, James D.

    2015-01-01

    When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools. - Highlights: • We examined the effects of ozone on Pieris brassicae performance and preference. • We studied ozone and herbivore induced changes in the metabolome of Brassica nigra. • The performance of P. brassicae did not correlate with preference of ozonated plants. • Ozone and herbivore-feeding stress changes the phytochemical pools of B. nigra. - Ozone indirectly reduces herbivore performance, which is associated with change in phytochemical pools, but does not correlate with host plant preference

  18. Ozone and infection of geranium flowers by Botrytis cinerea

    Energy Technology Data Exchange (ETDEWEB)

    Manning, W.J.; Feder, W.A.; Perkins, I.

    1970-01-01

    Flowering plants of geranium cultivars were exposed to 0.2, 0.35, and 0.55 ppm ozone for 4-hr periods at 20/sup 0/C in a greenhouse fumigation chamber. Three fully-opened flower heads were sprayed with a spore suspension of Botrytis cinerea at 2000, 1000, or 500 spores/ml immediately before exposure to ozone began. Sterile distilled water was sprayed on noninoculated flower heads. All flowers were examined for evidence of infection 24 hr after the end of the ozone-exposure periods. All flower heads were then removed and placed in wet, loosely tied plastic bags and incubated at 20/sup 0/C for 72 hr, with examination at 24-hr intervals for evidence of infection. Ozone at 0.2 ppm did not injure the plants or prevent or inhibit flower infection by B. cinerea at all inoculum levels. Natural infection also occurred on some noninoculated flowers. Ozone at 0.35 ppm did not injure the plants or prevent infection, but did inhibit pathogenesis at the 500-spore/ml inoculum level and on noninoculated flowers. Ozone at 0.55 ppm caused moderate injury on all plants. Ozone at this level did not prevent infection, but did restrict pathogenesis on all inoculated and noninoculated flowers.

  19. OZONE ABSORPTION IN RAW WATERS

    Directory of Open Access Journals (Sweden)

    LJILJANA TAKIĆ

    2008-03-01

    Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

  20. Ozone, greenhouse effect. Ozone, effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Aviam, A.M.; Arthaut, R.

    1992-12-01

    This file is made of eight general papers on environment (climates under observation, research on photo-oxidizing pollution, scientific aspects of stratospheric ozone layer, urban engineering and environment, glory of public gardens, earths not very natural, darwinism and society, economical data on environment). (A.B.). refs., 3 tabs.

  1. Automatic programmable air ozonizer

    International Nuclear Information System (INIS)

    Gubarev, S.P.; Klosovsky, A.V.; Opaleva, G.P.; Taran, V.S.; Zolototrubova, M.I.

    2015-01-01

    In this paper we describe a compact, economical, easy to manage auto air ozonator developed at the Institute of Plasma Physics of the NSC KIPT. It is designed for sanitation, disinfection of premises and cleaning the air from foreign odors. A distinctive feature of the developed device is the generation of a given concentration of ozone, approximately 0.7 maximum allowable concentration (MAC), and automatic maintenance of a specified level. This allows people to be inside the processed premises during operation. The microprocessor controller to control the operation of the ozonator was developed

  2. Enhancement of intrinsic antitumor activity in spore-endotoxin mixtures of Bacillus thuringiensis by exposure to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Zamola, B; Karminski-Zamola, G; Fuks, Z; Kubovic, M [Zagreb Univ. (Yugoslavia); Wrishcer, M [Institut Rudjer Boskovic, Zagreb (Yugoslavia)

    1985-03-01

    Irradiation of spore-endotoxin mixtures from Bacillus thuringiensis cultures at 254 nm (60 ..mu..W cm/sup -2/) enhances their intrinsic antitumor potency as well as that of either component. The extent of enhancement depends on the length of exposure (optimum: 35 min) and may thus be due to photochemical changes of the endotoxin protein or/and to photoproduction of additional compounds with antitumor activity. Antitumor effects, expressed as survival rates of C57BL/6 mice inoculated with Lewis' mouse lung carcinoma and subjected to treatments 24 h later, depended on the number of doses of preparations administered (mixture, separated components).

  3. Co-exposure to nickel and cobalt chloride enhances cytotoxicity and oxidative stress in human lung epithelial cells.

    Science.gov (United States)

    Patel, Eshan; Lynch, Christine; Ruff, Victoria; Reynolds, Mindy

    2012-02-01

    Nickel and cobalt are heavy metals found in land, water, and air that can enter the body primarily through the respiratory tract and accumulate to toxic levels. Nickel compounds are known to be carcinogenic to humans and animals, while cobalt compounds produce tumors in animals and are probably carcinogenic to humans. People working in industrial and manufacturing settings have an increased risk of exposure to these metals. The cytotoxicity of nickel and cobalt has individually been demonstrated; however, the underlying mechanisms of co-exposure to these heavy metals have not been explored. In this study, we investigated the effect of exposure of H460 human lung epithelial cells to nickel and cobalt, both alone and in combination, on cell survival, apoptotic mechanisms, and the generation of reactive oxygen species and double strand breaks. For simultaneous exposure, cells were exposed to a constant dose of 150 μM cobalt or nickel, which was found to be relatively nontoxic in single exposure experiments. We demonstrated that cells exposed simultaneously to cobalt and nickel exhibit a dose-dependent decrease in survival compared to the cells exposed to a single metal. The decrease in survival was the result of enhanced caspase 3 and 7 activation and cleavage of poly (ADP-ribose) polymerase. Co-exposure increased the production of ROS and the formation of double strand breaks. Pretreatment with N-acetyl cysteine alleviated the toxic responses. Collectively, this study demonstrates that co-exposure to cobalt and nickel is significantly more toxic than single exposure and that toxicity is related to the formation of ROS and DSB. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Effect of ozone and histamine on airway permeability to horseradish peroxidase in guinea pigs

    International Nuclear Information System (INIS)

    Miller, P.D.; Gordon, T.; Warnick, M.; Amdur, M.O.

    1986-01-01

    Airway permeability was studied in groups of male guinea pigs at 2, 8, and 24 h after a 1-h exposure to 1 ppm ozone or at 2 h after a 1-h exposure to filtered air (control). Intratracheal administration of 2 mg horseradish peroxidase (HRP) was followed by blood sampling at 5-min intervals up to 30 min. The rate of appearance of HRP in plasma was significantly higher at 2 and 8 h after ozone exposure than that found in animals examined 2 h after air exposure or 24 h after ozone exposure. A dose of 0.12 mg/kg of subcutaneous histamine given after the 15 min blood sample significantly increased the already elevated permeability seen at 2 h post ozone, but had no effect on animals exposed to filtered air 2 h earlier or to ozone 24 h earlier. No difference was seen in the amount of subcutaneous radiolabeled histamine in the lungs of animals exposed 2 h earlier either to air or to ozone. These data indicate that a short-term exposure to ozone produced a reversible increase in respiratory epithelial permeability to HRP in guinea pigs. The potentiation of this increased permeability by histamine may be another manifestation of ozone-induced hyperreactivity

  5. Ozone sonde cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    H. Vömel

    2010-04-01

    Full Text Available Laboratory measurements of the Electrochemical Concentration Cell (ECC ozone sonde cell current using ozone free air as well as defined amounts of ozone reveal that background current measurements during sonde preparation are neither constant as a function of time, nor constant as a function of ozone concentration. Using a background current, measured at a defined timed after exposure to high ozone may often overestimate the real background, leading to artificially low ozone concentrations in the upper tropical troposphere, and may frequently lead to operator dependent uncertainties. Based on these laboratory measurements an improved cell current to partial pressure conversion is proposed, which removes operator dependent variability in the background reading and possible artifacts in this measurement. Data from the Central Equatorial Pacific Experiment (CEPEX have been reprocessed using the improved background treatment based on these laboratory measurements. In the reprocessed data set near-zero ozone events no longer occur. At Samoa, Fiji, Tahiti, and San Cristóbal, nearly all near-zero ozone concentrations occur in soundings with larger background currents. To a large extent, these events are no longer observed in the reprocessed data set using the improved background treatment.

  6. Double dose: High family conflict enhances the effect of media violence exposure on adolescents’ aggression

    NARCIS (Netherlands)

    Fikkers, K.M.; Piotrowski, J.T.; Weeda, W.D.; Vossen, H.G.M.; Valkenburg, P.M.

    2013-01-01

    We investigated how exposure to media violence and family conflict affects adolescents’ subsequent aggressive behavior. We expected a double dose effect, meaning that high media violence exposure would lead to higher levels of aggression for adolescents in high conflict families compared to low

  7. A randomized noninferiority trial of standard versus enhanced risk reduction and adherence counseling for individuals receiving post-exposure prophylaxis following sexual exposures to HIV.

    Science.gov (United States)

    Roland, Michelle E; Neilands, Torsten B; Krone, Melissa R; Coates, Thomas J; Franses, Karena; Chesney, Margaret A; Kahn, James S; Martin, Jeffrey N

    2011-07-01

    The National HIV/AIDS Strategy proposes to scale-up post-exposure prophylaxis (PEP). Intensive risk reduction and adherence counseling appear to be effective but are resource intensive. Identifying simpler interventions that maximize the HIV prevention potential of PEP is critical. A randomized noninferiority study comparing 2 (standard) or 5 (enhanced) risk reduction counseling sessions was performed. Adherence counseling was provided in the enhanced arm. We measured changes in unprotected sexual intercourse acts at 12 months, compared with baseline; HIV acquisition; and PEP adherence. Outcomes were stratified by degree of baseline risk. We enrolled 457 individuals reporting unprotected intercourse within 72 h with an HIV-infected or at-risk partner. Participants were 96% male and 71% white. There were 1.8 and 2.3 fewer unprotected sex acts in the standard and enhanced groups. The maximum potential risk difference, reflected by the upper bound of the 95% confidence interval, was 3.9 acts. The difference in the riskier subset may have been as many as 19.6 acts. The incidence of HIV seroconversion was 2.9% and 2.6% among persons randomized to standard and enhanced counseling, respectively, with a maximum potential difference of 3.4%. The absolute and maximal HIV seroconversion incidence was 9.9% and 20.4% greater in the riskier group randomized to standard, compared with enhanced, counseling. Adherence outcomes were similar, with noninferiority in the lower risk group and concerning differences among the higher-risk group. Risk assessment is critical at PEP initiation. Standard counseling is only noninferior for individuals with lower baseline risk; thus, enhanced counseling should be targeted to individuals at higher risk. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.

  8. Lidar Measurements of Tropospheric Ozone in the Arctic

    Directory of Open Access Journals (Sweden)

    Seabrook Jeffrey

    2016-01-01

    Full Text Available This paper reports on differential absorption lidar (DIAL measurements of tropospheric ozone in the Canadian Arctic during springtime. Measurements at Eureka Weather Station revealed that mountains have a significant effect on the vertical structure of ozone above Ellesmere Island. Ozone depletion events were observed when air that had spent significant time near to the frozen surface of the Arctic Ocean reached Eureka. This air arrived at Eureka by flowing over the surrounding mountains. Surface level ozone depletions were not observed during periods when the flow of air from over the sea ice was blocked by mountains. In the case of blocking there was an enhancement in the amount of ozone near the surface as air from the mid troposphere descended in the lee of the mountains. Three case studies will be shown in the presentation, while one is described in this paper.

  9. Comparative study of ozonized olive oil and ozonized sunflower oil

    Directory of Open Access Journals (Sweden)

    Díaz Maritza F.

    2006-01-01

    Full Text Available In this study the ozonized olive and sunflower oils are chemical and microbiologically compared. These oils were introduced into a reactor with bubbling ozone gas in a water bath at room temperature until they were solidified. The peroxide, acidity and iodine values along with antimicrobial activity were determined. Ozonization effects on the fatty acid composition of these oils were analyzed using Gas-Liquid Chromatographic Technique. An increase in peroxidation and acidity values was observed in both oils but they were higher in ozonized sunflower oil. Iodine value was zero in ozonized olive oil whereas in ozonized sunflower was 8.8 g Iodine per 100 g. The antimicrobial activity was similar for both ozonized oils except for Minimum Bactericidal Concentrations of Pseudomona aeruginosa. Composition of fatty acids in both ozonized oils showed gradual decrease in unsaturated fatty acids (C18:1, C18:2 with gradual increase in ozone doses.

  10. Co-exposure to an ortho-substituted PCB (PCB 153) and methylmercury enhances developmental neurotoxic effects

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, C.; Fredriksson, A.; Eriksson, P. [Dept. Environment. Toxicol., Uppsala Univ. (Sweden)

    2004-09-15

    In our environment there are innumerable hazardous contaminants. Many of these compounds are the well-known persistent organic pollutants (POPs) like PCB and DDT. Another persistent agent in our environment is methylmercury (MeHg). These agents are known to be neurotoxic in laboratory animals and humans. Fetuses and neonates are known to be high-risk groups for exposure to these agents. A naturally occurring circumstance is the exposure to a combination of different persistent compounds. The knowledge of interaction between different toxic agents during development is sparse. In several studies we have shown that low-dose exposure of environmental toxic agents such as PCBs, DDT, BFRs (brominated flame retardants) as well as well-known neurotoxic agents such as nicotine, organophosphorous compounds and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), during the ''BGS'', in neonatal mice can lead to disruption of the adult brain function, and to an increased susceptibility to toxic agents as adults. Our studies concerning developmental neurotoxic effects after neonatal exposure to single PCB congeners have shown that some orthosubstituted PCBs (such as PCB 28, PCB 52, PCB 153) and some co-planar PCBs (such as PCB 77, PCB 126, PCB 169) cause derangement of adult behaviour that can worsen with age. Furthermore, the cholinergic receptors in the brain were also found to be affected8. Just recently we have seen that neonatal co-exposure to an ortho-substituted PCB, 2,2',5,5'-tetrachlorobiphenyl (PCB 52), together with a brominated flame retardant, 2,2',4,4',5-pentabromodiphenylether (PBDE 99), can enhance developmental neurotoxic effects when the exposure occurs during a critical stage of neonatal brain development. The present study was carried out in order to see whether PCB and MeHg could interact to cause enhanced developmental neurotoxic effects on spontaneous behaviour and habituation capability when given to neonatal mice.

  11. Male Sexual Behavior and Pheromone Emission Is Enhanced by Exposure to Guava Fruit Volatiles in Anastrepha fraterculus.

    Directory of Open Access Journals (Sweden)

    Guillermo E Bachmann

    Full Text Available Plant chemicals can affect reproductive strategies of tephritid fruit flies by influencing sex pheromone communication and increasing male mating competitiveness.We explored whether exposure of Anastrepha fraterculus males to guava fruit volatiles and to a synthetic blend of volatile compounds released by this fruit affects the sexual performance of wild and laboratory flies. By means of bioassays and pheromone collection we investigated the mechanism underlying this phenomenon.Guava volatile exposure enhanced male mating success and positively affected male calling behavior and pheromone release in laboratory and wild males. Changes in male behavior appear to be particularly important during the initial phase of the sexual activity period, when most of the mating pairs are formed. Exposure of laboratory males to a subset of guava fruit volatiles enhanced mating success, showing that the response to the fruit might be mimicked artificially.Volatiles of guava seem to influence male mating success through an enhancement of chemical and physical signals related to the communication between sexes. This finding has important implications for the management of this pest species through the Sterile Insect Technique. We discuss the possibility of using artificial blends to improve the sexual competitiveness of sterile males.

  12. Male Sexual Behavior and Pheromone Emission Is Enhanced by Exposure to Guava Fruit Volatiles in Anastrepha fraterculus

    Science.gov (United States)

    Bachmann, Guillermo E.; Segura, Diego F.; Devescovi, Francisco; Juárez, M. Laura; Ruiz, M. Josefina; Vera, M. Teresa; Cladera, Jorge L.; Fernández, Patricia C.

    2015-01-01

    Background Plant chemicals can affect reproductive strategies of tephritid fruit flies by influencing sex pheromone communication and increasing male mating competitiveness. Objective and Methodology We explored whether exposure of Anastrepha fraterculus males to guava fruit volatiles and to a synthetic blend of volatile compounds released by this fruit affects the sexual performance of wild and laboratory flies. By means of bioassays and pheromone collection we investigated the mechanism underlying this phenomenon. Results Guava volatile exposure enhanced male mating success and positively affected male calling behavior and pheromone release in laboratory and wild males. Changes in male behavior appear to be particularly important during the initial phase of the sexual activity period, when most of the mating pairs are formed. Exposure of laboratory males to a subset of guava fruit volatiles enhanced mating success, showing that the response to the fruit might be mimicked artificially. Conclusions Volatiles of guava seem to influence male mating success through an enhancement of chemical and physical signals related to the communication between sexes. This finding has important implications for the management of this pest species through the Sterile Insect Technique. We discuss the possibility of using artificial blends to improve the sexual competitiveness of sterile males. PMID:25923584

  13. Addressing Ozone Layer Depletion

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  14. Ozone Therapy in Dentistry

    Science.gov (United States)

    Domb, William C

    2014-01-01

    Summary The 21st century dental practice is quite dynamic. New treatment protocols and new materials are being developed at a rapid pace. Ozone dental therapy falls into the category of new treatment protocols in dentistry, yet ozone is not new at all. Ozone therapy is already a major treatment modality in Europe, South America and a number of other countries. What is provided here will not be an exhaustive scientific treatise so much as a brief general introduction into what dentists are now doing with ozone therapies and the numerous oral/systemic links that make this subject so important for physicians so that, ultimately, they may serve their patients more effectively and productively. PMID:25363268

  15. 2001 Ozone Design Value

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the...

  16. Exposure Estimation and Interpretation of Occupational Risk: Enhanced Information for the Occupational Risk Manager

    Science.gov (United States)

    Waters, Martha; McKernan, Lauralynn; Maier, Andrew; Jayjock, Michael; Schaeffer, Val; Brosseau, Lisa

    2015-01-01

    The fundamental goal of this article is to describe, define, and analyze the components of the risk characterization process for occupational exposures. Current methods are described for the probabilistic characterization of exposure, including newer techniques that have increasing applications for assessing data from occupational exposure scenarios. In addition, since the probability of health effects reflects variability in the exposure estimate as well as the dose-response curve—the integrated considerations of variability surrounding both components of the risk characterization provide greater information to the occupational hygienist. Probabilistic tools provide a more informed view of exposure as compared to use of discrete point estimates for these inputs to the risk characterization process. Active use of such tools for exposure and risk assessment will lead to a scientifically supported worker health protection program. Understanding the bases for an occupational risk assessment, focusing on important sources of variability and uncertainty enables characterizing occupational risk in terms of a probability, rather than a binary decision of acceptable risk or unacceptable risk. A critical review of existing methods highlights several conclusions: (1) exposure estimates and the dose-response are impacted by both variability and uncertainty and a well-developed risk characterization reflects and communicates this consideration; (2) occupational risk is probabilistic in nature and most accurately considered as a distribution, not a point estimate; and (3) occupational hygienists have a variety of tools available to incorporate concepts of risk characterization into occupational health and practice. PMID:26302336

  17. Enhanced removal of ethanolamine from secondary system of nuclear power plant wastewater by novel hybrid nano zero-valent iron and pressurized ozone initiated oxidation process.

    Science.gov (United States)

    Lee, Son Dong; Mallampati, Srinivasa Reddy; Lee, Byoung Ho

    2017-07-01

    Monoethanolamine (shortly ethanolamine (ETA)), usually used as a corrosion inhibitor, is a contaminant of wastewater from the secondary cooling system of nuclear power plants (NPPs) and is not readily biodegradable. We conducted various experiments, including treatments with nano zero-valent iron (nZVI), nano-iron/calcium, and calcium oxide (nFe/Ca/CaO) with ozone (O 3 ) or hydrogen peroxide (H 2 O 2 ) to reduce the concentration of ETA and to decrease the chemical demand of oxygen (COD) of these wastewaters. During this study, wastewater with ETA concentration of 7465 mg L -1 and COD of 6920 mg L -1 was used. As a result, the ETA concentration was reduced to 5 mg L -1 (a decrease of almost 100%) and COD was reduced to 2260 mg L -1 , a reduction of 67%, using doses of 26.8 mM of nZVI and 1.5 mM of H 2 O 2 at pH 3 for 3 h. Further treatment for 48 h allowed a decrease of COD by almost 97%. Some mechanistic considerations are proposed in order to explain the degradation pathway. The developed hybrid nano zero-valent iron-initiated oxidation process with H 2 O 2 is promising in the treatment of ETA-contaminated wastewaters.

  18. Impacts of stratospheric sulfate geoengineering on tropospheric ozone

    Science.gov (United States)

    Xia, Lili; Nowack, Peer J.; Tilmes, Simone; Robock, Alan

    2017-10-01

    A range of solar radiation management (SRM) techniques has been proposed to counter anthropogenic climate change. Here, we examine the potential effects of stratospheric sulfate aerosols and solar insolation reduction on tropospheric ozone and ozone at Earth's surface. Ozone is a key air pollutant, which can produce respiratory diseases and crop damage. Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosols and solar dimming on atmospheric ozone concentrations. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations, while sulfate injection decreases it. A fundamental difference between the two geoengineering schemes is the importance of heterogeneous reactions in the photochemical ozone balance with larger stratospheric sulfate abundance, resulting in increased ozone depletion in mid- and high latitudes. This reduces the net transport of stratospheric ozone into the troposphere and thus is a key driver of the overall decrease in surface ozone. At the same time, the change in stratospheric ozone alters the tropospheric photochemical environment due to enhanced ultraviolet radiation. A shared factor among both SRM scenarios is decreased chemical ozone loss due to reduced tropospheric humidity. Under insolation reduction, this is the dominant factor giving rise to the global surface ozone increase. Regionally, both surface ozone increases and decreases are found for both scenarios; that is, SRM would affect regions of the world differently in terms of air pollution. In conclusion

  19. Impacts of stratospheric sulfate geoengineering on tropospheric ozone

    Directory of Open Access Journals (Sweden)

    L. Xia

    2017-10-01

    Full Text Available A range of solar radiation management (SRM techniques has been proposed to counter anthropogenic climate change. Here, we examine the potential effects of stratospheric sulfate aerosols and solar insolation reduction on tropospheric ozone and ozone at Earth's surface. Ozone is a key air pollutant, which can produce respiratory diseases and crop damage. Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosols and solar dimming on atmospheric ozone concentrations. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations, while sulfate injection decreases it. A fundamental difference between the two geoengineering schemes is the importance of heterogeneous reactions in the photochemical ozone balance with larger stratospheric sulfate abundance, resulting in increased ozone depletion in mid- and high latitudes. This reduces the net transport of stratospheric ozone into the troposphere and thus is a key driver of the overall decrease in surface ozone. At the same time, the change in stratospheric ozone alters the tropospheric photochemical environment due to enhanced ultraviolet radiation. A shared factor among both SRM scenarios is decreased chemical ozone loss due to reduced tropospheric humidity. Under insolation reduction, this is the dominant factor giving rise to the global surface ozone increase. Regionally, both surface ozone increases and decreases are found for both scenarios; that is, SRM would affect regions of the world differently in terms of air

  20. The ozone backlash

    International Nuclear Information System (INIS)

    Taubes, G.

    1993-01-01

    While evidence for the role of chlorofluorocarbons in ozone depletion grows stronger, researchers have recently been subjected to vocal public criticism of their theories-and their motives. Their understanding of the mechanisms of ozone destruction-especially the annual ozone hole that appears in the Antarctic-has grown stronger, yet everywhere they go these days, they seem to be confronted by critics attacking their theories as baseless. For instance, Rush Limbaugh, the conservative political talk-show host and now-best-selling author of The Way Things Ought to Be, regularly insists that the theory of ozone depletion by CFCs is a hoax: bladerdash and poppycock. Zoologist Dixy Lee Ray, former governor of the state of Washington and former head of the Atomic Energy Commission, makes the same argument in her book, Trashing the Planet. The Wall Street Journal and National Review have run commentaries by S. Fred Singer, a former chief scientists for the Department of Transportation, purporting to shoot holes in the theory of ozone depletion. Even the June issue of Omni, a magazine with a circulation of more than 1 million that publishes a mixture of science and science fiction, printed a feature article claiming to expose ozone research as a politically motivated scam

  1. Ozone depletion calculations

    International Nuclear Information System (INIS)

    Luther, F.M.; Chang, J.S.; Wuebbles, D.J.; Penner, J.E.

    1992-01-01

    Models of stratospheric chemistry have been primarily directed toward an understanding of the behavior of stratospheric ozone. Initially this interest reflected the diagnostic role of ozone in the understanding of atmospheric transport processes. More recently, interest in stratospheric ozone has arisen from concern that human activities might affect the amount of stratospheric ozone, thereby affecting the ultraviolet radiation reaching the earth's surface and perhaps also affecting the climate with various potentially severe consequences for human welfare. This concern has inspired a substantial effort to develop both diagnostic and prognostic models of stratospheric ozone. During the past decade, several chemical agents have been determined to have potentially significant impacts on stratospheric ozone if they are released to the atmosphere in large quantities. These include oxides of nitrogen, oxides of hydrogen, chlorofluorocarbons, bromine compounds, fluorine compounds and carbon dioxide. In order to assess the potential impact of the perturbations caused by these chemicals, mathematical models have been developed to handle the complex coupling between chemical, radiative, and dynamical processes. Basic concepts in stratospheric modeling are reviewed

  2. Laboratory studies of immersion and deposition mode ice nucleation of ozone aged mineral dust particles

    Directory of Open Access Journals (Sweden)

    Z. A. Kanji

    2013-09-01

    Full Text Available Ice nucleation in the atmosphere is central to the understanding the microphysical properties of mixed-phase and cirrus clouds. Ambient conditions such as temperature (T and relative humidity (RH, as well as aerosol properties such as chemical composition and mixing state play an important role in predicting ice formation in the troposphere. Previous field studies have reported the absence of sulfate and organic compounds on mineral dust ice crystal residuals sampled at mountain top stations or aircraft based measurements despite the long-range transport mineral dust is subjected to. We present laboratory studies of ice nucleation for immersion and deposition mode on ozone aged mineral dust particles for 233 T ns are reported and observed to increase as a function of decreasing temperature. We present first results that demonstrate enhancement of the ice nucleation ability of aged mineral dust particles in both the deposition and immersion mode due to ageing. We also present the first results to show a suppression of heterogeneous ice nucleation activity without the condensation of a coating of (inorganic material. In immersion mode, low ozone exposed Ka particles showed enhanced ice activity requiring a median freezing temperature of 1.5 K warmer than that of untreated Ka, whereas high ozone exposed ATD particles showed suppressed ice nucleation requiring a median freezing temperature of 3 K colder than that of untreated ATD. In deposition mode, low exposure Ka had ice active fractions of an order of magnitude higher than untreated Ka, whereas high ozone exposed ATD had ice active fractions up to a factor of 4 lower than untreated ATD. From our results, we derive and present parameterizations in terms of ns(T that can be used in models to predict ice nuclei concentrations based on available aerosol surface area.

  3. Double Dose: High Family Conflict Enhances the Effect of Media Violence Exposure on Adolescents’ Aggression

    Directory of Open Access Journals (Sweden)

    Patti M. Valkenburg

    2013-07-01

    Full Text Available We investigated how exposure to media violence and family conflict affects adolescents’ subsequent aggressive behavior. We expected a double dose effect, meaning that high media violence exposure would lead to higher levels of aggression for adolescents in high conflict families compared to low conflict families. A total of 499 adolescents (aged 10 to 14, 48% girls participated in a two-wave longitudinal survey (4-month interval. Survey questions assessed their exposure to violence on television and in electronic games, family conflict, and aggressive behavior. Analyses revealed a significant interaction between media violence and family conflict. In families with higher conflict, higher media violence exposure was related to increased subsequent aggression. This study is the first to show a double dose effect of media violence and family conflict on adolescents’ aggression. These findings underscore the important role of the family in shaping the effects of adolescents’ media use on their social development.

  4. Yohimbine Enhancement of Exposure Therapy for Social Anxiety Disorder: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Smits, J.A.J.; Rosenfield, D.; Davis, M.L.; Julian, K.; Handelsman, P.R.; Otto, M.W.; Tuerk, P.; Shiekh, M.; Rosenfield, B.; Hofmann, S.G.; Powers, M.B.

    2014-01-01

    Background Preclinical and clinical trials suggest that yohimbine may augment extinction learning without significant side effects. However, previous clinical trials have only examined adults with specific phobias. Yohimbine has not yet been investigated in the augmentation of exposure therapy for

  5. Occurrence of ozone anomalies over cloudy areas in TOMS version-7 level-2 data

    Directory of Open Access Journals (Sweden)

    X. Liu

    2003-01-01

    Full Text Available This study investigates anomalous ozone distributions over cloudy areas in Nimbus-7 (N7 and Earth-Probe (EP TOMS version-7 data and analyzes the causes for ozone anomaly formation. A 5°-longitude by 5°-latitude region is defined to contain a Positive Ozone Anomaly (POA or Negative Ozone Anomaly (NOA if the correlation coefficient between total ozone and reflectivity is > 0.5 or -0.5. The average fractions of ozone anomalies among all cloud fields are 31.8 ± 7.7% and 35.8 ± 7.7% in the N7 and EP TOMS data, respectively. Some ozone anomalies are caused by ozone retrieval errors, and others are caused by actual geophysical phenomena. Large cloud-height errors are found in the TOMS version-7 algorithm in comparison to the Temperature Humidity Infrared Radiometer (THIR cloud data. On average, cloud-top pressures are overestimated by ~200 hPa (THIR cloud-top pressure 200 hPa for high-altitude clouds and underestimated by ~150 hPa for low-altitude clouds (THIR cloud-top pressure > 750 hPa. Most tropical NOAs result from negative errors induced by large cloud-height errors, and most tropical POAs are caused by positive errors due to intra-cloud ozone absorption enhancement. However, positive and negative errors offset each other, reducing the ozone anomaly occurrence in TOMS data. Large ozone/reflectivity slopes for mid-latitude POAs show seasonal variation consistent with total ozone fluctuation, indicating that they result mainly from synoptic and planetary wave disturbances. POAs with an occurrence fraction of 30--60% occur in regions of marine stratocumulus off the west coast of South Africa and off the west coast of South America. Both fractions and ozone/reflectivity slopes of these POAs show seasonal variations consistent with that in the tropospheric ozone. About half the ozone/reflectivity slope can be explained by ozone retrieval errors over clear and cloudy areas. The remaining slope may result from there being more ozone production

  6. Photochemical oxidants injury in rice plants. III. Effect of ozone on physiological activities in rice plants

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H; Saka, H

    1978-01-01

    Experiments were made to determine the effect of photochemical oxidants on physiological activities of rice plants. Rice plants were fumigated with ozone at concentrations of 0.12-0.20 ppm for 2-3 hr to investigate acute injury and at 0.05 and 0.09 ppm for daily exposure from 3.0 leaf stage to assess the effect of ozone on growth. It was observed that malondialdehyde produced by disruption of the components of the membrane increased in the leaves exposed to ozone. Ozone reduced the RuBP-carboxylase activity in both young and old leaves 12-24 hr after fumigation. In the young leaves the activity of this enzyme recovered to some extent after 48 hr, but it did not show any recovery in the old leaves. On the other hand, ozone remarkably increased the peroxidase activity and slightly increased acid phosphatase in all leaves. Abnormally high ethylene evolution and oxygen uptake were detected in leaves soon after ozone fumigation. In general, high molecular protein and chlorophyll contents in the detached leaves decreased with incubation in dark, particularly in the old ones. These phenomena were more accelerated by ozone fumigation. Kinetin and benzimidazole showed significant effects on chlorophyll retention in ozone-exposed leaves. Reduction of plant growth and photosynthetic rate was recognized even in low concentration of ozone in daily exposure at 0.05 and 0.09 ppm. From these results it was postulated that ozone may cause the senescence of leaves in rice plants.

  7. Trends in Surface Level Ozone Observations from Human-health Relevant Metrics: Results from the Tropospheric Ozone Assessment Report (TOAR)

    Science.gov (United States)

    Fleming, Z. L.; von Schneidemesser, E.; Doherty, R. M.; Malley, C.; Cooper, O. R.; Pinto, J. P.; Colette, A.; Xu, X.; Simpson, D.; Schultz, M.; Hamad, S.; Moola, R.; Solberg, S.; Feng, Z.

    2017-12-01

    Ozone is an air pollutant formed in the atmosphere from precursor species (NOx, VOCs, CH4, CO) that is detrimental to human health and ecosystems. The global Tropospheric Ozone Assessment Report (TOAR) initiative has assembled a global database of surface ozone observations and generated ozone exposure metrics at thousands of measurement sites around the world. This talk will present results from the assessment focused on those indicators most relevant to human health. Specifically, the trends in ozone, comparing different time periods and patterns across regions and among metrics will be addressed. In addition, the fraction of population exposed to high ozone levels and how this has changed between 2000 and 2014 will also be discussed. The core time period analyzed for trends was 2000-2014, selected to include a greater number of sites in East Asia. Negative trends were most commonly observed at many US and some European sites, whereas many sites in East Asia showed positive trends, while sites in Japan showed more of a mix of positive and negative trends. More than half of the sites showed a common direction and significance in the trends for all five human-health relevant metrics. The peak ozone metrics indicate a reduction in exposure to peak levels of ozone related to photochemical episodes in Europe and the US. A considerable number of European countries and states within the US have shown a decrease in population-weighted ozone over time. The 2000-2014 results will be augmented and compared to the trend analysis for additional time periods that cover a greater number of years, but by necessity are based on fewer sites. Trends are found to be statistically significant at a larger fraction of sites with longer time series, compared to the shorter (2000-2014) time series.

  8. The impacts of surface ozone pollution on winter wheat productivity in China – An econometric approach

    International Nuclear Information System (INIS)

    Yi, Fujin; Jiang, Fei; Zhong, Funing; Zhou, Xun; Ding, Aijun

    2016-01-01

    The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply. - Highlights: • We examine the impacts of the surface ozone exposure on winter wheat yield in China. • An econometric method is used to measure the ozone impacts. • The results conclude that surface ozone is harmful to winter wheat yield in China. • We confirm that stress conditions such as drought and air particles can mitigate the adverse effect of ozone. - Surface ozone pollution is harmful to winter wheat yield in China by considering socio-economic determinants, weather, and other stress conditions like drought and air particles.

  9. Fractal and variability analysis of simulations in ozone level due to oxides of nitrogen and sulphur

    Science.gov (United States)

    Bhardwaj, Rashmi; Pruthi, Dimple

    2017-10-01

    Air pollution refers to the release of pollutants into the air. These pollutants are detrimental to human the planet as a whole. Apart from causing respiratory infections and pulmonary disorders, rising levels of Nitrogen Dioxide is worsening ozone pollution. Formation of Ground-level ozone involves nitrogen oxides and volatile gases in the sunlight. Volatile gases are emitted from vehicles primarily. Ozone is harmful gas and its exposure can trigger serious health effects as it damages lung tissues. In order to decrease the level of ozone, level of oxides leading to ozone formation has to be dealt with. This paper deals with the simulations in ozone due to oxides of nitrogen and sulphur. The data from Central Pollution Control Board shows positive correlation for ozone with oxides of sulphur and nitrogen for RK Puram, Delhi in India where high concentration of ozone has been found. The correlation between ozone and sulphur, nitrogen oxides is moderate during summer while weak during winters. Ozone with nitrogen and sulphur dioxide follow persistent behavior as Hurst exponent is between 0.5 and 1. The fractal dimension for Sulphur dioxide is 1.4957 indicating the Brownian motion. The behavior of ozone is unpredictable as index of predictability is close to zero.

  10. Climate-driven ground-level ozone extreme in the fall over the Southeast United States.

    Science.gov (United States)

    Zhang, Yuzhong; Wang, Yuhang

    2016-09-06

    Ground-level ozone is adverse to human and vegetation health. High ground-level ozone concentrations usually occur over the United States in the summer, often referred to as the ozone season. However, observed monthly mean ozone concentrations in the southeastern United States were higher in October than July in 2010. The October ozone average in 2010 reached that of July in the past three decades (1980-2010). Our analysis shows that this extreme October ozone in 2010 over the Southeast is due in part to a dry and warm weather condition, which enhances photochemical production, air stagnation, and fire emissions. Observational evidence and modeling analysis also indicate that another significant contributor is enhanced emissions of biogenic isoprene, a major ozone precursor, from water-stressed plants under a dry and warm condition. The latter finding is corroborated by recent laboratory and field studies. This climate-induced biogenic control also explains the puzzling fact that the two extremes of high October ozone both occurred in the 2000s when anthropogenic emissions were lower than the 1980s and 1990s, in contrast to the observed decreasing trend of July ozone in the region. The occurrences of a drying and warming fall, projected by climate models, will likely lead to more active photochemistry, enhanced biogenic isoprene and fire emissions, an extension of the ozone season from summer to fall, and an increase of secondary organic aerosols in the Southeast, posing challenges to regional air quality management.

  11. Particulate matter air pollution may offset ozone damage to global crop production

    Science.gov (United States)

    Schiferl, Luke D.; Heald, Colette L.

    2018-04-01

    Ensuring global food security requires a comprehensive understanding of environmental pressures on food production, including the impacts of air quality. Surface ozone damages plants and decreases crop production; this effect has been extensively studied. In contrast, the presence of particulate matter (PM) in the atmosphere can be beneficial to crops given that enhanced light scattering leads to a more even and efficient distribution of photons which can outweigh total incoming radiation loss. This study quantifies the impacts of ozone and PM on the global production of maize, rice, and wheat in 2010 and 2050. We show that accounting for the growing season of these crops is an important factor in determining their air pollution exposure. We find that the effect of PM can offset much, if not all, of the reduction in yield associated with ozone damage. Assuming maximum sensitivity to PM, the current (2010) global net impact of air quality on crop production varies by crop (+5.6, -3.7, and +4.5 % for maize, wheat, and rice, respectively). Future emissions scenarios indicate that attempts to improve air quality can result in a net negative effect on crop production in areas dominated by the PM effect. However, we caution that the uncertainty in this assessment is large, due to the uncertainty associated with crop response to changes in diffuse radiation; this highlights that a more detailed physiological study of this response for common cultivars is crucial.

  12. Particulate matter air pollution may offset ozone damage to global crop production

    Directory of Open Access Journals (Sweden)

    L. D. Schiferl

    2018-04-01

    Full Text Available Ensuring global food security requires a comprehensive understanding of environmental pressures on food production, including the impacts of air quality. Surface ozone damages plants and decreases crop production; this effect has been extensively studied. In contrast, the presence of particulate matter (PM in the atmosphere can be beneficial to crops given that enhanced light scattering leads to a more even and efficient distribution of photons which can outweigh total incoming radiation loss. This study quantifies the impacts of ozone and PM on the global production of maize, rice, and wheat in 2010 and 2050. We show that accounting for the growing season of these crops is an important factor in determining their air pollution exposure. We find that the effect of PM can offset much, if not all, of the reduction in yield associated with ozone damage. Assuming maximum sensitivity to PM, the current (2010 global net impact of air quality on crop production varies by crop (+5.6, −3.7, and +4.5 % for maize, wheat, and rice, respectively. Future emissions scenarios indicate that attempts to improve air quality can result in a net negative effect on crop production in areas dominated by the PM effect. However, we caution that the uncertainty in this assessment is large, due to the uncertainty associated with crop response to changes in diffuse radiation; this highlights that a more detailed physiological study of this response for common cultivars is crucial.

  13. Ozone modeling within plasmas for ozone sensor applications

    OpenAIRE

    Arshak, Khalil; Forde, Edward; Guiney, Ivor

    2007-01-01

    peer-reviewed Ozone (03) is potentially hazardous to human health and accurate prediction and measurement of this gas is essential in addressing its associated health risks. This paper presents theory to predict the levels of ozone concentration emittedfrom a dielectric barrier discharge (DBD) plasma for ozone sensing applications. This is done by postulating the kinetic model for ozone generation, with a DBD plasma at atmospheric pressure in air, in the form of a set of rate equations....

  14. Analysis of European ozone trends in the period 1995-2014

    Science.gov (United States)

    Yan, Yingying; Pozzer, Andrea; Ojha, Narendra; Lin, Jintai; Lelieveld, Jos

    2018-04-01

    Surface-based measurements from the EMEP and Airbase networks are used to estimate the changes in surface ozone levels during the 1995-2014 period over Europe. We find significant ozone enhancements (0.20-0.59 µg m-3 yr-1 for the annual means; P-value climate model EMAC, the importance of anthropogenic emissions changes in determining these changes over background sites are investigated. The EMAC model is found to successfully capture the observed temporal variability in mean ozone concentrations, as well as the contrast in the trends of 95th and 5th percentile ozone over Europe. Sensitivity simulations and statistical analysis show that a decrease in European anthropogenic emissions had contrasting effects on surface ozone trends between the 95th and 5th percentile levels and that background ozone levels have been influenced by hemispheric transport, while climate variability generally regulated the inter-annual variations of surface ozone in Europe.

  15. CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

    Science.gov (United States)

    This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

  16. Natural zeolite reactivity towards ozone: The role of compensating cations

    International Nuclear Information System (INIS)

    Valdés, Héctor; Alejandro, Serguei; Zaror, Claudio A.

    2012-01-01

    Highlights: ► Chemical and thermal treatment enhances catalytic activity of natural zeolite. ► Modified natural zeolite exhibits high stability after thermal treatment. ► Reducing the compensating cation content leads to an increase on ozone abatement. ► Surface active atomic oxygen was detected using the DRIFT technique. ► The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L −1 ). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH 3 -TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  17. Coincident Observations of Surface Ozone and NMVOCs over Abu Dhabi

    Science.gov (United States)

    Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Tarasick, David; Davies, Jonathan; Riemer, Daniel; Apel, Eric

    2016-07-01

    The vertical profiles of ozone are measured coincidently with non-methane volatile organic compounds (NMVOCs) at the meteorological site located at the Abu Dhabi international airport (latitude 24.45N; longitude 54.22E) during the years 2012 - 2014. Some of the profiles show elevated surface ozone >95 ppbv during the winter months (December, January and February). The ground-level NMVOCs obtained from the gas chromatography-flame ionization detection/mass spectrometry system also show elevated values of acetylene, ethane, propane, butane, pentane, benzene, and toluene. NMVOCs and ozone abundances in other seasons are much lower than the values in winter season. NMVOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption, and serve as precursor of ozone. Transport sources contribute a substantial portion of the NMVOC burden to the urban atmosphere in developed regions. Abu Dhabi is located at the edge of the Arabian Gulf and is highly affected by emissions from petrochemical industries in the neighboring Gulf region. The preliminary results indicate that wintertime enhancement in ozone is associated with large values of NMVOCs at Abu Dhabi. The domestic production of surface ozone is estimated from the combination of oxygen recombination and NMVOCs and compared with the data. It is estimated that about 40-50% of ozone in Abu Dhabi is transported from the neighbouring petrochemical industries. We will present ozone sounding and NMVOCs data and our model estimates of surface ozone, including a discussion on the high levels of the tropospheric ozone responsible for contaminating the air quality in the UAE. This work is supported by National Research Foundation, UAE.

  18. Natural zeolite reactivity towards ozone: The role of compensating cations

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, Hector, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologias Limpias (F. Ingenieria), Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, Concepcion (Chile); Alejandro, Serguei; Zaror, Claudio A. [Departamento de Ingenieria Quimica (F. Ingenieria), Universidad de Concepcion, Concepcion (Chile)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Chemical and thermal treatment enhances catalytic activity of natural zeolite. Black-Right-Pointing-Pointer Modified natural zeolite exhibits high stability after thermal treatment. Black-Right-Pointing-Pointer Reducing the compensating cation content leads to an increase on ozone abatement. Black-Right-Pointing-Pointer Surface active atomic oxygen was detected using the DRIFT technique. Black-Right-Pointing-Pointer The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L{sup -1}). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH{sub 3}-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  19. Ozone-depleting Substances (ODS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

  20. Air Quality Guide for Ozone

    Science.gov (United States)

    GO! Local Air Quality Conditions Zip Code: State : My Current Location Air Quality Guide for Ozone Ground-level ozone is one of our nation’s most common air pollutants. Use the chart below to help reduce ...

  1. Enhancing graphical literacy skills in the high school science classroom via authentic, intensive data collection and graphical representation exposure

    Science.gov (United States)

    Palmeri, Anthony

    This research project was developed to provide extensive practice and exposure to data collection and data representation in a high school science classroom. The student population engaged in this study included 40 high school sophomores enrolled in two microbiology classes. Laboratory investigations and activities were deliberately designed to include quantitative data collection that necessitated organization and graphical representation. These activities were embedded into the curriculum and conducted in conjunction with the normal and expected course content, rather than as a separate entity. It was expected that routine practice with graph construction and interpretation would result in improved competency when graphing data and proficiency in analyzing graphs. To objectively test the effectiveness in achieving this goal, a pre-test and post-test that included graph construction, interpretation, interpolation, extrapolation, and analysis was administered. Based on the results of a paired T-Test, graphical literacy was significantly enhanced by extensive practice and exposure to data representation.

  2. Self-esteem threat combined with exposure to thin media images leads to body image compensatory self-enhancement.

    Science.gov (United States)

    Jarry, Josée L; Kossert, Amy L

    2007-03-01

    This study examined the effect of a self-esteem threat combined with exposure to thin images on body image (BI) satisfaction and investment. Female participants (N=94) received a self-esteem threat consisting of false failure feedback or received false success feedback on an intellectual task allegedly highly predictive of academic and professional success. They then viewed media images featuring thin models or products. After viewing thin models, women who had received failure feedback declared themselves more satisfied about their appearance and less invested in it than did women who had received success feedback. These results suggest that exposure to the thin ideal may inspire women experiencing self-esteem threats to use appearance as an alternative source of worth, thus maintaining their global esteem through BI compensatory self-enhancement. Potential long-term implications of this strategy, such as a paradoxical increase in BI investment and the development of eating pathology, are discussed.

  3. Seasonal and diurnal gas exchange differences in ozone-sensitive common milkweed (Asclepias syriaca L.) in relation to ozone uptake.

    Science.gov (United States)

    Bergweiler, Chris; Manning, William J; Chevone, Boris I

    2008-03-01

    Stomatal conductance and net photosynthesis of common milkweed (Asclepias syriaca L.) plants in two different soil moisture regimes were directly quantified and subsequently modeled over an entire growing season. Direct measurements captured the dynamic response of stomatal conductance to changing environmental conditions throughout the day, as well as declining gas exchange and carbon assimilation throughout the growth period beyond an early summer maximum. This phenomenon was observed in plants grown both with and without supplemental soil moisture, the latter of which should theoretically mitigate against harmful physiological effects caused by exposure to ozone. Seasonally declining rates of stomatal conductance were found to be substantial and incorporated into models, making them less susceptible to the overestimations of effective exposure that are an inherent source of error in ozone exposure indices. The species-specific evidence presented here supports the integration of dynamic physiological processes into flux-based modeling approaches for the prediction of ozone injury in vegetation.

  4. Tropospheric Ozone Assessment Report: Database and Metrics Data of Global Surface Ozone Observations

    Directory of Open Access Journals (Sweden)

    Martin G. Schultz

    2017-10-01

    Full Text Available In support of the first Tropospheric Ozone Assessment Report (TOAR a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone data products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues, which are part of this special feature. Cooperation among many data centers and individual researchers worldwide made it possible to build the world's largest collection of 'in-situ' hourly surface ozone data covering the period from 1970 to 2015. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allows for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone and they enable TOAR to perform the first, globally consistent analysis of present-day ozone concentrations and recent ozone changes with relevance to health, agriculture, and climate. Considerable effort was made to harmonize and synthesize data formats and metadata information from various networks and individual data submissions. Extensive quality control was applied to identify questionable and erroneous data, including changes in apparent instrument offsets or calibrations. Such data were excluded from TOAR data products. Limitations of 'a posteriori' data quality assurance are discussed. As a result of the work presented here, global coverage of surface ozone data for scientific analysis has been significantly extended. Yet, large gaps remain in the surface

  5. Self-enhancing effects of exposure to thin-body images.

    Science.gov (United States)

    Joshi, Ramona; Herman, C Peter; Polivy, Janet

    2004-04-01

    This study examines the effect of thin-body media images on mood, self-esteem, and self-image ratings of restrained and unrestrained eaters. A secondary purpose was to examine whether these effects were influenced by exposure duration. Under the guise of a perception study, participants were exposed to thin-body or control advertisements (e.g., perfume bottles) for either 7 or 150 ms and then completed a questionnaire packet. Restrained eaters reported more favorable self-image and social self-esteem (but not appearance self-esteem) scores after exposure to thin-body images than after exposure to control advertisements. The self-image and social self-esteem scores of unrestrained eaters were unaffected by advertisement type, but their appearance self-esteem scores were lower after exposure to thin-body advertisements. No differences were found for mood ratings and total self-esteem. We discuss restraint status as a moderator of the effects of thin-body images on women's body image. Copyright 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 333-341, 2004.

  6. Sugammadex-Enhanced Neuronal Apoptosis following Neonatal Sevoflurane Exposure in Mice

    Directory of Open Access Journals (Sweden)

    Maiko Satomoto

    2016-01-01

    Full Text Available In rodents, neonatal sevoflurane exposure induces neonatal apoptosis in the brain and results in learning deficits. Sugammadex is a new selective neuromuscular blockade (NMB binding agent that anesthesiologists can use to achieve immediate reversal of an NMB with few side effects. Given its molecular weight of 2178, sugammadex is thought to be unable to pass through the blood brain barrier (BBB. Volatile anesthetics can influence BBB opening and integrity. Therefore, we investigated whether the intraperitoneal administration of sugammadex could exacerbate neuronal damage following neonatal 2% sevoflurane exposure via changes in BBB integrity. Cleaved caspase-3 immunoblotting was used to detect apoptosis, and the ultrastructure of the BBB was examined by transmission electron microscopy. Exposure to 2% sevoflurane for 6 h resulted in BBB ultrastructural abnormalities in the hippocampus of neonatal mice. Sugammadex alone without sevoflurane did not induce apoptosis. The coadministration of sugammadex with sevoflurane to neonatal mice caused a significant increase (150% in neuroapoptosis in the brain compared with 2% sevoflurane. In neonatal anesthesia, sugammadex could influence neurotoxicity together with sevoflurane. Exposure to 2% sevoflurane for 6 h resulted in BBB ultrastructural abnormalities in the hippocampus of neonatal mice.

  7. Enhancing Exposure and Response Prevention for OCD: A Couple-Based Approach

    Science.gov (United States)

    Abramowitz, Jonathan S.; Baucom, Donald H.; Wheaton, Michael G.; Boeding, Sara; Fabricant, Laura E.; Paprocki, Christine; Fischer, Melanie S.

    2013-01-01

    The effectiveness of individual therapy by exposure and response prevention (ERP) for obsessive-compulsive disorder (OCD) is well established, yet not all patients respond well, and some show relapse on discontinuation. This article begins by providing an overview of the personal and interpersonal experiences of OCD, focusing on interpersonal…

  8. Pharmacological enhancement of exposure-based treatment in PTSD: a qualitative review

    NARCIS (Netherlands)

    Kleine, R.A. de; Rothbaum, B.O.; Minnen, A. van

    2013-01-01

    There is a good amount of evidence that exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD). Notwithstanding its efficacy, there is room for improvement, since a large proportion of patients does not benefit from treatment. Recently, an interesting new direction in

  9. Dark exposure of petunia cuttings strongly improves adventitious root formation and enhances carbohydrate availability during rooting in the light.

    Science.gov (United States)

    Klopotek, Yvonne; Haensch, Klaus-Thomas; Hause, Bettina; Hajirezaei, Mohammad-Reza; Druege, Uwe

    2010-05-01

    The effect of temporary dark exposure on adventitious root formation (ARF) in Petuniaxhybrida 'Mitchell' cuttings was investigated. Histological and metabolic changes in the cuttings during the dark treatment and subsequent rooting in the light were recorded. Excised cuttings were exposed to the dark for seven days at 10 degrees C followed by a nine-day rooting period in perlite or were rooted immediately for 16 days in a climate chamber at 22/20 degrees C (day/night) and a photosynthetic photon flux density (PPFD) of 100micromolm(-2)s(-1). Dark exposure prior to rooting increased, accelerated and synchronized ARF. The rooting period was reduced from 16 days (non-treated cuttings) to 9 days (treated cuttings). Under optimum conditions, despite the reduced rooting period, dark-exposed cuttings produced a higher number and length of roots than non-treated cuttings. An increase in temperature to 20 degrees C during the dark treatment or extending the cold dark exposure to 14 days caused a similar enhancement of root development compared to non-treated cuttings. Root meristem formation had already started during the dark treatment and was enhanced during the subsequent rooting period. Levels of soluble sugars (glucose, fructose and sucrose) and starch in leaf and basal stem tissues significantly decreased during the seven days of dark exposure. This depletion was, however, compensated during rooting after 6 and 24h for soluble sugars in leaves and the basal stem, respectively, whereas the sucrose level in the basal stem was already increased at 6h. The association of higher carbohydrate levels with improved rooting in previously dark-exposed versus non-treated cuttings indicates that increased post-darkness carbohydrate availability and allocation towards the stem base contribute to ARF under the influence of dark treatment and provide energy for cell growth subject to a rising sink intensity in the base of the cutting. Copyright 2009 Elsevier GmbH. All rights reserved.

  10. The biological effects of ozone on representative members of five groups of animal viruses

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, D.C.; Zee, Y.C.; Osebold, J.W.

    1982-04-01

    In an effort to establish the biological relevance of the reactions of ozone with soluble proteins and lipid bilayer membrane systems, representative viruses from five major virus groups were exposed to moderate concentrations of ozone. The virus suspensions were exposed at 37/sup 0/C to 0.00, 0.16, and 0.64 ppm ozone in the gas phase. The ozone reacted with the virus suspensions as a thin film of fluid on the surface of a rotating culture bottle as the gas was drawn through the bottle at a flow rate of 2 liters/min. The three enveloped viruses tested exhibited different susceptibilities to ozone inactivation which correlated with their thermolability in the absence of ozone. The order of susceptibility to ozone inactivation of the enveloped viruses was vesicular stomatitis virus (VSV) (Rhabdoviridae) > influenza A virus (WSN strain) (Orthomyxoviridae) > infectious bovine rhinotracheitis virus (IBRV) (Herpesviridae). The inactivation reactions of the enveloped viruses with ozone showed pseudo-first-order kinetics. A simple reaction model was used to derive a reaction rate expression from which rate constrants and reaction stoichiometry were estimated. In contrast to the enveloped viruses, the two nonenveloped viruses examined were relatively resistant to ozone inactivation. Polio virus type I (Picornaviridae) was found to be completely resistant to ozone inactivation after 60 hr exposure to either ozone concentration, while infectious canine hepatitis virus (Adenoviridae) showed only slight inactivation after exposure to 0.64 ppm ozone for 66 hr. The significance of these results with regard to the reactions of ozone with cell membranes and other components is discussed.

  11. Monitoring ambient ozone with a passive measurement technique method, field results and strategy

    NARCIS (Netherlands)

    Scheeren, BA; Adema, EH

    1996-01-01

    A low-cost, accurate and sensitive passive measurement method for ozone has been developed and tested. The method is based on the reaction of ozone with indigo carmine which results in colourless reaction products which are detected spectrophotometrically after exposure. Coated glass filters are

  12. CARRY-OVER EFFECTS OF OZONE ON ROOT GROWTH AND CARBOHYDRATE CONCENTRATIONS OF PONDEROSA PINE SEEDLINGS

    Science.gov (United States)

    Ozone exposure decreases belowground carbon allocation and root growth of plants;however,the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood.To evaluate the potential for plant compensation,we followed the prog...