WorldWideScience

Sample records for ambient ozone growth

  1. Interactive effects of ambient ozone and climate measured on growth of mature loblolly pine trees

    McLaughlin, S.B. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Downing, D.J. [Oak Ridge National Lab., TN (United States). Engineering Physics and Mathematics Div.

    1996-04-01

    The effects of ambient ozone on the growth of large trees were evaluated. A 6-year study was conducted at a site in eastern Tennessee where seasonal growth patterns of mature loblolly pine trees were analysed. Patterns of stem expansion and contraction of 34 trees were studied using serial measurements with dendrometer band systems. Soil moisture, soil fertility and stand density were varied. Levels of ozone, rainfall and temperature also varied. Results showed that ozone interacted with both soil moisture stress and high temperatures. It was concluded that relatively low levels of ambient ozone can significantly reduce growth of mature forest tress and interactions between ambient ozone and climate were important modifiers of future forest growth and function. 49 refs., 6 tabs., 4 figs.

  2. Interactive effects of ambient ozone and climate measured on growth of mature loblolly pine trees

    McLaughlin, S.B.; Downing, D.J.

    1995-02-01

    Analysis of the seasonal growth patterns of mature loblolly pine trees over the interval 1988-1993 has provided the first direct measurement of reductions of stem growth of large forest trees by ambient ozone. Patterns of stem expansion and contraction of 34 trees were examined in eastern Tennessee using serial measurements with sensitive dendrometer bind systems. Study sites varied in soil moisture, soil fertility, and stand density. Levels of ozone, rainfall, and temperature varied widely over the six year study interval. Regression analysis identified statistically and biologically significant influences of ozone on stem growth. Acting either individually or in interaction with high temperature and moisture stress, higher levels of ozone were associated with reduced stem expansion of individual trees within and across years. Observed responses to ozone were relatively rapid, differed widely among trees, and across years, and were significantly amplified by low soil moisture and high air temperatures. Both short term responses, clearly tied to changing stem water status, and longer term cumulative responses were identified. These data indicate that relatively low levels of ambient ozone can significantly reduce growth of mature forest trees and that interactions between ambient ozone and climate are likely to be important modifiers of future forest growth and function. Additional studies of mechanisms of short term response and inter species comparisons are clearly needed.

  3. Assessing plant response to ambient ozone: growth of young apple trees in open-top chambers and corresponding ambient air plots

    Open-top chambers (OTCs) and corresponding ambient air plots (AA) were used to assess the impact of ambient ozone on growth of newly planted apple trees at the Montague Field research center in Amherst, MA. Two-year-old apple trees (Malus domestica Borkh 'Rogers Red McIntosh') were planted in the ground in circular plots. Four of the plots were enclosed with OTCs where incoming air was charcoal-filtered (CF); four were enclosed with OTCs where incoming air was not charcoal-filtered (NF) and four were not enclosed, allowing access to ambient air conditions (AA). Conditions in both CF and NF OTCs resulted in increased tree growth and changed incidence of disease and arthropod pests, compared to trees in AA. As a result, we were not able to use the OTC method to assess the impact of ambient ozone on growth of young apple trees in Amherst, MA. - Capsule: Conditions in charcoal-filtered and non-filtered open-top chambers affected apple tree growth equally and prevented assessment of ambient ozone effects

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

    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

  5. Contribution of ambient ozone to Scots pine defoliation and reduced growth in the Central European forests: A Lithuanian case study

    The study aimed to explore if changes in crown defoliation and stem growth of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone (O3) concentration in central Europe. To meet this objective the study was performed in 3 Lithuanian national parks, close to the ICP integrated monitoring stations from which data on meteorology and pollution were provided. Contribution of peak O3 concentrations to the integrated impact of acidifying compounds and meteorological parameters on pine stem growth was found to be more significant than its contribution to the integrated impact of acidifying compounds and meteorological parameters on pine defoliation. Findings of the study provide statistical evidence that peak concentrations of ambient O3 can have a negative impact on pine tree crown defoliation and stem growth reduction under field conditions in central and northeastern Europe where the AOT40 values for forests are commonly below their phytotoxic levels. - Peak ozone concentrations is one of the key factors affecting Scots pine trees

  6. Evaluation of physiological, growth and yield responses of a tropical oil crop (Brassica campestris L. var. Kranti) under ambient ozone pollution at varying NPK levels

    A field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O3 concentration varied from 41.65 to 54.2 ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O3. - NPK level above recommended alleviates the adverse effects of ambient ozone on a tropical mustard cultivar

  7. Assessing the impact of ambient ozone on growth and yield of a rice (Oryza sativa L.) and a wheat (Triticum aestivum L.) cultivar grown in the Yangtze Delta, China, using three rates of application of ethylenediurea (EDU)

    Foliar applications of ethylenediurea (abbreviated as EDU) were made at 0, 150, 300 or 450 ppm to field-grown rice and wheat in the Yangtze Delta in China. Rice and wheat responded differently to ambient ozone and EDU applications. For wheat, some growth characteristics, such as yield, seed number per plant, seed set rate and harvest index, increased significantly at 300 ppm EDU treatment, while for rice no parameters measured were statistically different regarding EDU application. The reason may be that the wheat cultivar used may be more sensitive to ozone than the rice cultivar. EDU was effective in demonstrating ozone effects on the wheat cultivar, but not on the rice cultivar. Cultivar sensitivity might be an important consideration when assessing the effects of ambient ozone on plants. - Cultivar sensitivity should be considered when using protective chemical to assess the effects of ambient ozone on plants

  8. Bioindicator plants for ambient ozone in Central and Eastern Europe

    Sixteen species of native detector plants for ambient ozone have been identified for use in Central and Eastern Europe. They include the forbs Alchemilla sp., Astrantia major, Centuarea nigra, Centauria scabiosa, Impatiens parviflora, Lapsana communis, Rumex acetosa and Senecio subalpinus; the shrubs Corylus avellana, Cornus sanguinea and Sambucus racemosa; the trees Alnus incana, Pinus cembra and Sorbus aucuparia; and the vines Humulus lupulus and Parthenocissus quinquefolia. Sensitivity to ozone and symptoms have been verified under controlled exposure conditions. Under these conditions, symptom incidence, intensity and appearance often changed with time after removal from exposure chambers. Ozone sensitivity for four species: Astrantia major, Centuarea nigra, C. scabiosa and Humulus lupulus are reported here for the first time. The other 12 species have also been confirmed by others in Western Europe. It is recommended that these detector bioindicator species be used in conjunction with ozone monitors and passive samplers so that injury symptoms incidence can be used to give biological significance to monitored ambient ozone data. - Sixteen species of verified bioindicator plants for ambient ozone are available for use in Central and Eastern Europe

  9. Effects of a three-year exposure to ambient ozone on biomass allocation in poplar using ethylenediurea

    We examined the effect of ambient ozone on visible foliar injury, growth and biomass in field-grown poplar cuttings of an Oxford clone sensitive to ozone (Populus maximoviczii Henry × berolinensis Dippel) irrigated with ethylenediurea (EDU) or water for three years. EDU is used as an ozone protectant for plants. Protective effects of EDU on ozone visible injury were found. As a result, poplar trees grown under EDU treatment increased leaves, lateral branches and root density in the third year, although no significant enhancement of stem height and diameter was found. Ambient ozone (AOT40, 24.6 ppm h; diurnal hourly average, 40.3 ppb) may finally reduce carbon gain by reducing the number of branches, and thus sites for leaf formation, in ozone-sensitive poplar trees under not-limiting conditions. -- Highlights: •A fast-growing ozone-sensitive poplar clone was treated with the ozone protectant ethylenediurea (EDU) for three years. •Ambient ozone reduced allocation of biomass to leaves, roots and lateral branches. •Effects on stem length and diameter were not significant. •EDU protected from ozone visible foliar injury and reduction of biomass accumulation. -- Ozone reduced allocation of biomass to leaves, roots and lateral branches, but did not affect stem length and diameter

  10. The response of rice grain quality to ozone exposure during growth depends on ozone level and genotype

    The effects of ozone exposure during the cropping season on rice grain quality were investigated in chamber experiments employing four ozone treatments (charcoal filtered air, ambient, 2× ambient, and 2.5× ambient concentration) and six genotypes. The concentrations of protein and lipids in brown rice increased significantly in response to ozone, while starch concentration and thousand kernel mass decreased. Other parameters, including the concentrations of iron, zinc, phenolics, stickiness and geometrical traits did not exhibit significant treatment effects. Total brown rice yield, protein yield, and iron yield were negatively affected by ozone. Numerous genotypic differences occurred in the response to ozone, indicating the possibility of optimizing the grain quality in high ozone environments by breeding. It is concluded that although the concentrations of two important macronutrients, proteins and lipids, increased in ozone treated grains, the implications for human nutrition are negative due to losses in total grain, protein and iron yield. - Highlights: ► Exposure of rice plants to elevated ozone during growth led to altered grain quality. ► Protein and lipid concentration increased whereas starch concentration and thousand kernel weight decreased. ► Rice grain, protein and iron yield tended to decrease in plants exposed to high ozone. ► These effects were responsive to different ozone levels and showed genotypic differences. ► The overall effect of ozone o human nutrition is expected to be negative. - Ozone exposure during growth tends to increase the protein and lipid concentration in rice grains but decreases total grain and nutrient yields. These effects are dependent on ozone level and genotype.

  11. Association between ambient ozone and health outcomes in Prague

    Hůnová, I.; Malý, Marek; Řezáčová, J.; Braniš, M.

    2013-01-01

    Roč. 86, č. 1 (2013), s. 89-97. ISSN 0340-0131 Grant ostatní: GA MŠk(CZ) 2B08077; GA AV ČR(CZ) M100300904 Institutional research plan: CEZ:AV0Z10300504 Keywords : ambient ozone * cardiovascular diseases * hospital admissions * mortality * respiratory diseases Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.198, year: 2013

  12. Ambient Ozone and Emergency Department Visits for Cellulitis

    Mieczysław Szyszkowicz

    2010-11-01

    Full Text Available Objectives were to assess and estimate an association between exposure to ground-level ozone and emergency department (ED visits for cellulitis. All ED visits for cellulitis in Edmonton, Canada, in the period April 1992–March 2002 (N = 69,547 were examined. Case-crossover design was applied to estimate odds ratio (OR, and 95% confidence interval per one interquartile range (IQR increase in ozone concentration (IQR = 14.0 ppb. Delay of ED visit relating to exposure was probed using 0- to 5-day exposure lags. For all patients in the all months (January–December and lags 0 to 2 days, OR = 1.05 (1.02, 1.07. For male patients during the cold months (October-March: OR = 1.05 (1.02, 1.09 for lags 0 and 2 and OR = 1.06 (1.02, 1.10 for lag 3. For female patients in the warm months (April-September: OR = 1.12 (1.06, 1.18 for lags 1 and 2. Cellulitis developing on uncovered (more exposed skin was analyzed separately, observed effects being stronger. Cellulitis may be associated with exposure to ambient ground level ozone; the exposure may facilitate cellulitis infection and aggravate acute symptoms.

  13. Ambient ozone concentration and emergency department visits for panic attacks.

    Cho, Jaelim; Choi, Yoon Jung; Sohn, Jungwoo; Suh, Mina; Cho, Seong-Kyung; Ha, Kyoung Hwa; Kim, Changsoo; Shin, Dong Chun

    2015-03-01

    The effect of ambient air pollution on panic disorder in the general population has not yet been thoroughly elucidated, although the occurrence of panic disorder in workers exposed to organic solvents has been reported previously. We investigated the association of ambient air pollution with the risk of panic attack-related emergency department visits. Using health insurance claims, we collected data from emergency department visits for panic attacks in Seoul, Republic of Korea (2005-2009). Daily air pollutant concentrations were obtained using automatic monitoring system data. We conducted a time-series study using a generalized additive model with Poisson distribution, which included spline variables (date of visit, daily mean temperature, and relative humidity) and parametric variables (daily mean air pollutant concentration, national holiday, and day of the week). In addition to single lag models (lag1 to lag3), cumulative lag models (lag0-1 to lag0-3) were constructed using moving-average concentrations on the days leading up to the visit. The risk was expressed as relative risk (RR) per one standard deviation of each air pollutant and its 95% confidence interval (95% CI). A total of 2320 emergency department visits for panic attacks were observed during the study period. The adjusted RR of panic attack-related emergency department visits was 1.051 (95% CI, 1.014-1.090) for same-day exposure to ozone. In cumulative models, adjusted RRs were 1.068 (1.029-1.107) in lag0-2 and 1.074 (1.035-1.114) in lag0-3. The ambient ozone concentration was significantly associated with emergency department visits for panic attacks. PMID:25669697

  14. Ozone flux to vegetation and its relationship to plant response and ambient air quality standards

    Musselman, Robert C.; Massman, William J.

    The National Ambient Air Quality Standard (NAAQS) for ozone is based on occurrences of the maximum 8 h average ambient ozone concentration. However, biologists have recommended a cumulative ozone exposure parameter to protect vegetation. In this paper we propose a third alternative which uses quantifiable flux-based numerical parameters as a replacement for cumulative ambient parameters. Herein we discuss the concept of ozone flux as it relates to plant response and the NAAQS, and document information needed before a flux-based ozone NAAQS for vegetation can be implemented. Additional research is needed in techniques for determining plant uptake and in the quantification of plant defensive mechanisms to ozone. Models which include feedback mechanisms should be developed to relate ozone flux, loading, and detoxification with photosynthesis and plant productivity.

  15. Comparative analysis of seed transcriptomes of ambient ozone-fumigated 2 different rice cultivars

    Cho, Kyoungwon; Shibato, Junko; Kubo, Akihiro; Kohno, Yoshihisa; Satoh, Kouji; Kikuchi, Shoshi; Sarkar, Abhijit; Agrawal, Ganesh Kumar; Rakwal, Randeep

    2013-01-01

    High ozone (O3) concentrations not only damage plant life but also cause considerable losses in plant productivity. To screen for molecular factors usable as potential biomarkers to identify for O3-sensitive and -tolerant lines and design O3 tolerant crops, our project examines the effects of O3 on rice, using high-throughput omics approaches. In this study, we examined growth and yield parameters of 4 rice cultivars fumigated for a life-time with ambient air (mean O3: 31.4–32.7 ppb) or filte...

  16. Nocturnal stomatal conductance and ambient air quality standards for ozone

    Musselman, Robert C.; Minnick, Tamera J.

    Vegetation response to ozone depends on ozone conductance into leaves and the defensive action inside the leaf. Ozone parameters currently used for air quality standards do not incorporate conductance or defensive components. Nighttime flux has often been ignored in ozone metrics relating to plant response, since ozone concentration and conductance are considered to be minimal at night. However, ozone concentration can remain relatively high at night, particularly in mountainous areas. Although conductance is lower at night than during the day for most plants, nocturnal conductance can result in considerable ozone flux into plants. Further, plants can be more susceptible to ozone exposure at night than during the daytime, a result of lower plant defenses at night. Any ozone metric used to relate air quality to plant response should use a 24 h ozone exposure period to include the nighttime exposures. It should also incorporate plant defensive mechanisms or their surrogate.

  17. Modelling ambient ozone in an urban area using an objective model and geostatistical algorithms

    Moral, Francisco J.; Rebollo, Francisco J.; Valiente, Pablo; López, Fernando; Muñoz de la Peña, Arsenio

    2012-12-01

    Ground-level tropospheric ozone is one of the air pollutants of most concern. Ozone levels continue to exceed both target values and the long-term objectives established in EU legislation to protect human health and prevent damage to ecosystems, agricultural crops and materials. Researchers or decision-makers frequently need information about atmospheric pollution patterns in urbanized areas. The preparation of this type of information is a complex task, due to the influence of several factors and their variability over time. In this work, some results of urban ozone distribution patterns in the city of Badajoz, which is the largest (140,000 inhabitants) and most industrialized city in Extremadura region (southwest Spain) are shown. Twelve sampling campaigns, one per month, were carried out to measure ambient air ozone concentrations, during periods that were selected according to favourable conditions to ozone production, using an automatic portable analyzer. Later, to evaluate the overall ozone level at each sampling location during the time interval considered, the measured ozone data were analysed using a new methodology based on the formulation of the Rasch model. As a result, a measure of overall ozone level which consolidates the monthly ground-level ozone measurements was obtained, getting moreover information about the influence on the overall ozone level of each monthly ozone measure. Finally, overall ozone level at locations where no measurements were available was estimated with geostatistical techniques and hazard assessment maps based on the spatial distribution of ozone were also generated.

  18. Assessing the effects of ambient ozone in China on snap bean genotypes by using ethylenediurea (EDU)

    Four genotypes of snap bean (Phaseolus vulgaris L.) were selected to study the effects of ambient ozone concentration at a cropland area around Beijing by using 450 ppm of ethylenediurea (EDU) as a chemical protectant. During the growing season, the 8 h (9:00–17:00) average ozone concentration was very high, approximately 71.3 ppb, and AOT40 was 29.0 ppm.h. All genotypes showed foliar injury, but ozone-sensitive genotypes exhibited much more injury than ozone-tolerant ones. Compared with control, EDU significantly alleviated foliar injury, increased photosynthesis rate and chlorophyll a fluorescence, Vcmax and Jmax, and seed and pod weights in ozone-sensitive genotypes but not in ozone-tolerant genotypes. EDU did not significantly affect antioxidant contents in any of the genotypes. Therefore, EDU effectively protected sensitive genotypes from ambient ozone damage, while protection on ozone-tolerant genotypes was limited. EDU can be regarded as a useful tool in risk assessment of ambient ozone on food security. - Highlights: • The average O3 concentration (9–17 h) was 71 ppb from June to August in Beijing. • Four genotypes of snap bean (Phaseolus vulgaris L.) were selected. • EDU effectively protected sensitive genotypes from ambient O3 damage. • The protection of EDU on O3-tolerant genotypes was limited. • EDU can be regarded as a useful tool in risk assessment of ambient O3 on vegetation. - EDU protects sensitive snap bean genotypes from ambient O3

  19. 77 FR 51798 - First Draft Documents Related to the Review of the National Ambient Air Quality Standards for Ozone

    2012-08-27

    ... AGENCY First Draft Documents Related to the Review of the National Ambient Air Quality Standards for... of the Ozone National Ambient Air Quality Standards: First External Review Draft. The Agency is... titled, Policy Assessment for the Review of the Ozone National Ambient Air Quality Standards:...

  20. Constraining ozone-precursor responsiveness using ambient measurements

    This study develops probabilistic estimates of ozone (O3) sensitivities to precursoremissions by incorporating uncertainties in photochemical modeling and evaluating modelperformance based on ground-level observations of O3 and oxides of nitrogen (NOx).Uncertainties in model form...

  1. The Role of Ambient Ozone in Epidemiologic Studies of Heat-Related Mortality

    Reid, Colleen E.; Snowden, Jonathan M.; KONTGIS, Caitlin; Tager, Ira B.

    2012-01-01

    Background: A large and growing literature investigating the role of extreme heat on mortality has conceptualized the role of ambient ozone in various ways, sometimes treating it as a confounder, sometimes as an effect modifier, and sometimes as a co-exposure. Thus, there is a lack of consensus about the roles that temperature and ozone together play in causing mortality. Objectives: We applied directed acyclic graphs (DAGs) to the topic of heat-related mortality to graphically represent the ...

  2. Ambient ozone and emergency department visits due to lower respiratory condition

    Termeh Kousha; Brian Rowe

    2014-01-01

    Objectives: Ambient ozone (O3) exposure is associated with a variety of health conditions. The objective of this study was to examine the effect of increased daily concentrations of ozone on emergency department (ED) visits due to lower respiratory diseases (LRD), such as acute or chronic bronchitis, in Edmonton, Canada. Materials and Methods: Data concerning 10 years (1992-2002) were obtained from 5 Edmonton hospital Emergency Departments. Odds ratios (ORs) for ED visits associated with the ...

  3. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National 8-hour primary and secondary....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  4. 77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards

    2012-05-21

    ... Columbia EPA Environmental Protection Agency FR Federal Register NAAQS National Ambient Air Quality... ppm NAAQS set in 1997, but is set at a more protective level. \\2\\ See 73 FR 16436; March 27, 2008. For... 6, 2010. (See 75 FR 2938; January 19, 2010.) Because of the significant uncertainty the ozone...

  5. Moderate drought did not affect the effectiveness of ethylenediurea (EDU) in protecting Populus cathayana from ambient ozone.

    Xin, Yue; Yuan, Xiangyang; Shang, Bo; Manning, William J; Yang, Aizhen; Wang, Younian; Feng, Zhaozhong

    2016-11-01

    A field study was conducted to evaluate the effects of ambient ozone (O3) on an O3-sensitive poplar (Populus cathayana) by using ethylenediurea (EDU) as a chemical protectant under two soil water treatments (well-watered (WW) and moderate drought (MD, 50-60% of WW in volumetric soil water content). EDU was applied as foliar spray at 0, 300, 450, and 600ppm. Photosynthetic parameters, pigment contents, leaf nitrogen, antioxidant capacity, growth, and biomass were measured. The 8h (9:00-17:00) average ambient O3 concentration was 71.7ppb, and AOT40 was 29.2ppmh during the experimental period (9 June to 21 September), which was high enough to cause plant injury. MD had significantly negative effects on P. cathayana, as indicated by reduced photosynthesis, growth, and biomass, and higher MDA contents. On the other hand, EDU significantly increased photosynthesis rate, chlorophyll a fluorescence, Vcmax and Jmax, photosynthetic pigments, total antioxidant capacity, tree growth and biomass accumulation, and reduced lipid peroxidation, but there was no significant interaction between EDU and drought for most parameters, indicating that EDU can efficiently protect Populus cathayana against ambient O3 and the protection was not affected by soil water contents when soil water reached moderate drought level. Among all doses, EDU at 450ppm provided maximum protection. Comparison of EDU-treated and non-treated P. cathayana could be used as a biomarker system in risk assessment of the effects of ambient O3 on forest health. PMID:27424114

  6. Impact of Climate Change on Ambient Ozone Level and Mortality in Southeastern United States

    Montserrat Fuentes

    2010-07-01

    Full Text Available There is a growing interest in quantifying the health impacts of climate change. This paper examines the risks of future ozone levels on non-accidental mortality across 19 urban communities in Southeastern United States. We present a modeling framework that integrates data from climate model outputs, historical meteorology and ozone observations, and a health surveillance database. We first modeled present-day relationships between observed maximum daily 8-hour average ozone concentrations and meteorology measured during the year 2000. Future ozone concentrations for the period 2041 to 2050 were then projected using calibrated climate model output data from the North American Regional Climate Change Assessment Program. Daily community-level mortality counts for the period 1987 to 2000 were obtained from the National Mortality, Morbidity and Air Pollution Study. Controlling for temperature, dew-point temperature, and seasonality, relative risks associated with short-term exposure to ambient ozone during the summer months were estimated using a multi-site time series design. We estimated an increase of 0.43 ppb (95% PI: 0.14–0.75 in average ozone concentration during the 2040’s compared to 2000 due to climate change alone. This corresponds to a 0.01% increase in mortality rate and 45.2 (95% PI: 3.26–87.1 premature deaths in the study communities attributable to the increase in future ozone level.

  7. Ambient ozone and bacterium Streptococcus: A link between cellulitis and pharyngitis

    Giuseppe Valacchi

    2015-08-01

    Full Text Available Objectives: Ambient air pollution, as many publications indicate, may have associations with skin condition. The aim of this study has been to examine such common relations for cellulitis and pharyngitis. The hypothesis is that ambient ground-level ozone may help bacteria to penetrate skin or throat. Material and Methods: We used the emergency department (ED visits data in Edmonton, Canada for the period from 1992 (April to 2002 (March. We retrieved all the diagnosed ED visits for cellulitis and pharyngitis. Case-crossover design was used to study potential association between ozone and those visits. Conditional logistic regression was used to estimate odds ratios (OR and their 95% confidence intervals (95% CI. Results: The results are reported for the interquartile range (IQR = 17.9 ppb for 8 h maximum ozone. Positive and statistical significant results were obtained as follows: for lags from 0 to 3 (OR = 1.07, 95% CI: 1.03–1.12, lag 2; for lags from 0 to 6 days (OR = 1.08, 95% CI: 1.03–1.12, lag 3; for lags from 0 to 4 (OR = 1.06, 95% CI: 1.03–1.09, for lag 2 and 3. Conclusions: The findings suggest the response to exposure to ambient ground-level ozone for skin and pharyngitis considered separately and jointly.

  8. US Environmental Protection Agency's ozone epidemiology research program: A strategy for assessing the effects of ambient ozone exposure upon morbidity in exposed populations

    McDonnell, W.F.; Zenick, H.; Hayes, C.G.

    1993-01-01

    The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. In order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potential health benefits of improved air quality, the Health Effects Research Laboratory of the U.S. EPA has undertaken an Ozone Epidemiology Research Program. The three questions identified as being of most immediate importance involve the relationship of short-term ambient ozone exposure to acute respiratory illness, the relationship of recurrent exposure to chronic respiratory disease, and the relationship of recurrent exposure to development of acute respiratory illness. (Copyright (c) 1993 Air and Waste Management Association.)

  9. Ozone air pollution effects on tree-ring growth,{delta}{sup 13}C, visible foliar injury and leaf gas exchange in three ozone-sensitive woody plant species

    Novak, K. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland); Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Saurer, M. [Paul Scherrer Inst. Villigen (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Skelly, J.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology; Krauchi, N.; Schaub, M. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

    2007-07-15

    Species specific plant responses to tropospheric ozone pollution depend on a range of morphological, biochemical and physiological characteristics as well as environmental factors. The effects of ambient tropospheric ozone on annual tree-ring growth, {delta}{sup 13} C in the rings, leaf gas exchange and ozone-induced visible foliar injury in three ozone-sensitive woody plant species in southern Switzerland were assessed during the 2001 and 2002 growing seasons. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air and non-filtered air in open-top chambers, and to ambient air (AA) in open plots. The objective was to determine if a relationship exists between measurable ozone-induced effects at the leaf level and subsequent changes in annual tree-ring growth and {delta} {sup 13} C signatures. The visible foliar injury, early leaf senescence and premature leaf loss in all species was attributed to the ambient ozone exposures in the region. Ozone had pronounced negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular carbon dioxide concentrations increased in all species in response to ozone in 2002 only. The width and {delta}{sup 13} C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased {delta}{sup 13} C in all species, suggesting that the timing of ozone exposure and extent of leaf-level responses may be relevant in determining the sensitivity of tree productivity to ozone exposure. 48 refs., 4 tabs., 2 figs.

  10. Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance

    Lagerkvist, Birgitta Json; Bernard, Alfred; Blomberg, Anders; Bergstrom, Erik; Forsberg, Bertil; Holmstrom, Karin; Karp, Kjell; Lundstrom, Nils-Goran; Segerstedt, Bo; Svensson, Mona; Nordberg, Gunnar

    2004-01-01

    Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O3 exposure and swimming pool attendance. The measurements were made on 57 ...

  11. Simulation of ozone depletion using ambient irradiance supplemented with UV lamps.

    Díaz, S; Camilión, C; Escobar, J; Deferrari, G; Roy, S; Lacoste, K; Demers, S; Belzile, C; Ferreyra, G; Gianesella, S; Gosselin, M; Nozais, C; Pelletier, E; Schloss, I; Vernet, M

    2006-01-01

    In studies of the biological effects of UV radiation, ozone depletion can be mimicked by performing the study under ambient conditions and adding radiation with UV-B lamps. We evaluated this methodology at three different locations along a latitudinal gradient: Rimouski (Canada), Ubatuba (Brazil) and Ushuaia (Argentina). Experiments of the effect of potential ozone depletion on marine ecosystems were carried out in large outdoor enclosures (mesocosms). In all locations we simulated irradiances corresponding to 60% ozone depletion, which may produce a 130-1900% increase in 305 nm irradiance at noon, depending on site and season. Supplementation with a fixed percentage of ambient irradiance provides a better simulation of irradiance increase due to ozone depletion than supplementation with a fixed irradiance value, particularly near sunrise and sunset or under cloudy skies. Calculations performed for Ushuaia showed that, on very cloudy days, supplementation by the square-wave method may produce unrealistic irradiances. Differences between the spectra of the calculated supplementing irradiance and the lamp for a given site and date will be a function of the time of day and may become more or less pronounced according to the biological weighting function of the effect under study. PMID:17205620

  12. Ambient ozone and emergency department visits due to lower respiratory condition

    Termeh Kousha

    2014-02-01

    Full Text Available Objectives: Ambient ozone (O3 exposure is associated with a variety of health conditions. The objective of this study was to examine the effect of increased daily concentrations of ozone on emergency department (ED visits due to lower respiratory diseases (LRD, such as acute or chronic bronchitis, in Edmonton, Canada. Materials and Methods: Data concerning 10 years (1992-2002 were obtained from 5 Edmonton hospital Emergency Departments. Odds ratios (ORs for ED visits associated with the increased ozone levels were calculated employing a case-crossover technique with a time-stratified strategy to define controls. In the constructed conditional logistic regression models, adjustments were made for daily number of influenza ED visits and weather variables using natural splines. ORs and their 95% confidence intervals (95% CI were reported in relation to an increase in the interquartile range (IQR = 17.9 ppb of the ground-level ozone. Results: Overall, 48 252 ED visits due to LRD were identified, of which 53% were made by males. The presentations peaked in December (12% and February (11.7% and were the lowest in August (5.6%. Positive and statistically significant results were obtained for acute bronchitis: for same day (OR = 1.09, 95% CI: 1.05-1.13, lag 0 and for lag 2, lag 3-7 and 9 days; for chronic bronchitis: for lag 6, 7, and lag 9 days (OR = 1.11, 95% CI: 1.05-1.18, lag 9. For all ED visits for LRD, lag 0, lag 1, and lag 3-9 days showed positive and statistically significant associations (OR = 1.06, 95% CI: 1.03-1.09, lag 0. Conclusions: These findings support the hypothesis concerning positive associations between ozone and the ED visits due to LRD.

  13. Ameliorating effect of UV-B radiation on the response of Norway spruce and Scots pine to ambient ozone concentrations

    Elevated levels of both ozone and UV-B radiation are typical for high-altitude sites. Few studies have investigated their possible interaction on plants. This study reports interactive effects of O3 and UV-B radiation in four-year-old Norway spruce and Scots pine trees. The trees were cultivated in controlled environmental facilities under simulated climatic conditions recorded on Mt Wank, an Alpine mountain in Bavaria, and were exposed for one growing season to simulated ambient or twice-ambient ozone regimes at either near ambient or near zero UV-B radiation levels. Chlorotic mottling and yellowing of current year needles became obvious under twice-ambient O3 in both species at the onset of a high ozone episode in July. Development of chlorotic mottling in relation to accumulated ozone concentrations over a threshold of 40 nL L–1 was more pronounced with near zero rather than ambient UV-B radiation levels. In Norway spruce, photosynthetic parameters at ambient CO2 concentration, measured at the end of the experiment, were reduced in trees cultivated under twice-ambient O3, irrespective of the UV-B treatment. Effects on photosynthetic capacity and carboxylation efficiency were restricted to trees exposed to near zero levels of UV-B radiation, and twice-ambient O3. The data indicate that UV-B radiation, applied together with O3, ameliorates the detrimental effects of O3. The data also demonstrate that foliar symptoms develop more rapidly in Scots pine than in Norway spruce at higher accumulated ozone concentrations. (author)

  14. Estimating contribution of wildland fires to ambient ozone levels in National Parks in the Sierra Nevada, California

    Data from four continuous ozone and weather monitoring sites operated by the National Park Service in Sierra Nevada, California, are used to develop an ozone forecasting model and to estimate the contribution of wildland fires on ambient ozone levels. The analyses of weather and ozone data pointed to the transport of ozone precursors from the Central Valley as an important source of pollution in these National Parks. Comparisons of forecasted and observed values demonstrated that accurate forecasts of next-day hourly ozone levels may be achieved by using a time series model with historic averages, expected local weather and modeled PM values as explanatory variables. Results on fire smoke influence indicated occurrence of significant increases in average ozone levels with increasing fire activity. The overall effect on diurnal ozone values, however, was small when compared with the amount of variability attributed to sources other than fire. - We have demonstrated that it is possible to produce accurate forecasts of next-day hourly ozone levels in the Sierra Nevada, CA, during fire season.

  15. US Environmental Protection Agency's Ozone Epidemiology Research Program: A strategy for assessing the effects of ambient ozone exposure upon morbidity in exposed populations

    McDonnell, W.F.; Zenick, H.; Hayes, C.G. (Environmental Protection Agency, Research Triangle Park, NC (United States))

    1993-07-01

    The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. In order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potential health benefits of improved air quality, the Health Effects Research Laboratory of the U.S. EPA has undertaken an Ozone Epidemiology Research Program. The research strategy which will guide this scientific program is described in this paper. Criteria for selection of important research questions as well as issues which cut across all questions and study designs are discussed. In particular, this program emphasizes the study of effects which reflect morbidity in the population. The three questions identified as being of most immediate importance involve the relationship of short-term ambient ozone exposure to acute respiratory illness, the relationship of recurrent exposure to chronic respiratory disease, and the relationship of recurrent exposure to development of acute respiratory illness. Specific research approaches and initial projects to address these three questions are described.

  16. Does ozone exposure alter growth and carbon allocation of mycorrhizal plants

    Yoshida, L.C.; Gamon, J.A. (California State Univ., Los Angeles, CA (United States)); Andersen, C.P. (Environmental Protection Agency, Corvallis, OR (United States))

    1994-06-01

    Ozone is known to adversely affect plant growth. However, it is less clear how ozone affects belowground processes. This study tests the hypothesis that ozone alters growth and carbon allocation of vesicular arbuscular mycorrhizal (VAM) plants. Two ecotypes of Elymus glaucus (blue wild rye) were exposed to mycorrhizal inoculation and episodic ozone exposures simulating atmospheric conditions in the Los Angeles Basin. Preliminary results show that effects of ozone on growth were subtle. In both ecotypes, growth of aboveground biomass was not affected by ozone while root growth was decreased. In most treatments, mycorrhizal inoculation decreased growth of leaves and stems, but had no significant effect on root growth. Three-way ANOVA tests indicated interactive effects between ecotype, mycorrhiza and ozone. Further experimental work is needed to reveal the biological processes governing these responses.

  17. Tempo-Spatial Variations of Ambient Ozone-Mortality Associations in the USA: Results from the NMMAPS Data.

    Liu, Tao; Zeng, Weilin; Lin, Hualiang; Rutherford, Shannon; Xiao, Jianpeng; Li, Xing; Li, Zhihao; Qian, Zhengmin; Feng, Baixiang; Ma, Wenjun

    2016-01-01

    Although the health effects of ambient ozone have been widely assessed, their tempo-spatial variations remain unclear. We selected 20 communities (ten each from southern and northern USA) based on the US National Morbidity, Mortality, and Air Pollution Study (NMMAPS) dataset. A generalized linear model (GLM) was used to estimate the season-specific association between each 10 ppb (lag0-2 day average) increment in daily 8 h maximum ozone concentration and mortality in every community. The results showed that in the southern communities, a 10 ppb increment in ozone was linked to an increment of mortality of -0.07%, -0.17%, 0.40% and 0.27% in spring, summer, autumn and winter, respectively. For the northern communities, the excess risks (ERs) were 0.74%, 1.21%, 0.52% and -0.65% in the spring, summer, autumn and winter seasons, respectively. City-specific ozone-related mortality effects were positively related with latitude, but negatively related with seasonal average temperature in the spring, summer and autumn seasons. However, a reverse relationship was found in the winter. We concluded that there were different seasonal patterns of ozone effects on mortality between southern and northern US communities. Latitude and seasonal average temperature were identified as modifiers of the ambient ozone-related mortality risks. PMID:27571094

  18. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    2010-07-01

    ...-hour standards are codified in 40 CFR part 81. (c) EPA's authority under paragraph (b) of this section... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National 1-hour primary and secondary....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level...

  19. Evaluation and Comparison of Methods for Measuring Ozone and NO2 Concentrations in Ambient Air during DISCOVER-AQ

    Ambient evaluations of the various ozone and NO2 methods were conducted during field intensive studies as part of the NASA DISCOVER-AQ project conducted during July 2011 near Baltimore, MD; January – February 2013 in the San Juaquin valley, CA; September 2013 in Houston, TX...

  20. Ambient ozone phytotoxic potential over the Czech forests as assessed by AOT40

    Hunova I

    2012-06-01

    Full Text Available Ambient ozone (O3 represents one of the most prominent air pollution pro­blems in Europe. We present an analysis on O3 with respect to its phytotoxic potential over Czech forests between 1994 and 2008. The phytotoxic potential is estimated based on the exposure index AOT40 for forests calculated from real-time monitoring data at 24 rural sites. Our results indicate high phytotoxic potential for most of the Czech Republic (CR with considerable inter-annual and spatial variability. The highest AOT40 values were 38-39 ppm·h. The cri­tical level for forest protection (5 ppm·h was usually exceeded early in the growing season, generally in May. In years with meteorological conditions conducive to ozone formation, the critical level was exceeded by 5-7 folds as compared to years with non-conducive conditions; nevertheless, all sites consi­stently exceeded the critical level since 1994. In the extremely hot and dry year 2003, the critical level for forests was exceeded over 31 % of the Czech forested area. More research is needed to translate these exceedances into forest injury in the CR.

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

    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.

  2. Photosynthesis and growth response of almond to increased atmospheric ozone partial pressures

    Uniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, cv. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domstica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O3) partial pressures. The trees were planted in open-top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O3 partial pressures lasted from 1 June to 2 Nov. 1989. The mean 12-h [0800-2000 h Pacific Daylight Time (PDT)] O3 partial pressures measured in the open-top chambers during the experimental period were 0.038, 0.060, and 0.112 μPa Pa-1 O3 in the charcoal filtered, ambient, and ambient + O3 treatments, respectively. Leaf net CO2 assimilation, trunk cross-sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O3 partial pressures. Mission was unaffected by O3 and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O3 treatments. The results indicate that there are almond cultivars that are sensitive to O3 exposure

  3. Trends analyses of 30 years of ambient 8 hour ozone and precursor monitoring data in the South Central U.S.: progress and challenges.

    Sather, Mark E; Cavender, Kevin

    2016-07-13

    In the last 30 years ambient ozone concentrations have notably decreased in the South Central U.S. Yet, current ambient ozone concentrations measured over the past three years 2013-2015 in this area of the U.S. are not meeting the U.S. 2015 8 hour ozone standard of 70 parts per billion (ppb). This paper provides an update on long-term trends analyses of ambient 8 hour ozone and ozone precursor monitoring data collected over the past 30 years (1986-2015) in four South Central U.S. cities, following up on two previously published reviews of 20 and 25 year trends for these cities. All four cities have benefitted from national ozone precursor controls put in place during the 1990s and 2000s involving cleaner vehicles (vehicle fleet turnover/replacement over time), cleaner fuels, cleaner gasoline and diesel engines, and improved inspection/maintenance programs for existing vehicles. Additional ozone precursor emission controls specific to each city are detailed in this paper. The controls have resulted in impressive ambient ozone and ambient ozone precursor concentration reductions in the four South Central U.S. cities over the past 30 years, including 31-70% ambient nitrogen oxides (NOx) concentration declines from historical peaks to the present, 43-72% volatile organic compound (VOC) concentration declines from historical peaks to the present, a related 45-76% VOC reactivity decline for a subset of VOC species from historical peaks to the present, and an 18-38 ppb reduction in city 8 hour ozone design value concentrations. A new challenge for each of the four South Central U.S. cities will be meeting the U.S. 2015 8 hour ozone standard of 70 ppb. PMID:27282109

  4. Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion

    Bernacchi, Carl J., E-mail: bernacch@illinois.edu [Global Change and Photosynthesis Research Unit, United States Department of Agriculture Agricultural Research Service, Urbana, IL 61801 (United States); Institute for Genomic Biology and Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Leakey, Andrew D.B. [Institute for Genomic Biology and Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Kimball, Bruce A. [USDA-ARS US Arid-Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ 85238 (United States); Ort, Donald R. [Global Change and Photosynthesis Research Unit, United States Department of Agriculture Agricultural Research Service, Urbana, IL 61801 (United States); Institute for Genomic Biology and Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2011-06-15

    Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O{sub 3}]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O{sub 3}] on crop ecosystem energy fluxes and water use. Elevated [O{sub 3}] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 deg. C. - Highlights: > Globally, tropospheric ozone is currently and will likely continue to increase into the future. > We examine the impact of elevated ozone on water use by soybean at the SoyFACE research facility. > High ozone grown soybean had reduced rates of evapotranspiration and higher soil moisture. > Increases in ozone have the potential to impact the hydrologic cycle where these crops are grown. - Soybean grown in elevated concentrations of ozone is shown to evapotranspire less water compared with soybean canopies grown under current atmospheric conditions.

  5. Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion

    Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O3]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O3] on crop ecosystem energy fluxes and water use. Elevated [O3] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 deg. C. - Highlights: → Globally, tropospheric ozone is currently and will likely continue to increase into the future. → We examine the impact of elevated ozone on water use by soybean at the SoyFACE research facility. → High ozone grown soybean had reduced rates of evapotranspiration and higher soil moisture. → Increases in ozone have the potential to impact the hydrologic cycle where these crops are grown. - Soybean grown in elevated concentrations of ozone is shown to evapotranspire less water compared with soybean canopies grown under current atmospheric conditions.

  6. Effective interface passivation of a Ge/HfO2 gate stack using ozone pre-gate treatment and ozone ambient annealing

    The physical and electrical properties of a Ge/GeO2/HfO2/Al gate stack are investigated. A thin interfacial GeO2 layer (∼1 nm) is formed between Ge and HfO2 by dual ozone treatments, which passivates the Ge/high-k interface. Capacitors on p-type Ge substrates show very promising capacitance-voltage (C—V) characteristics by using in situ pre-gate ozone passivation and ozone ambient annealing after high-k deposition, indicating efficient passivation of the Ge/HfO2 interface. It is shown that the mid-gap interface state density atthe Ge/GeO2 interface is 6.4 × 1011 cm−2 · eV−1. In addition, the gate leakage current density of the Ge/GeO2/HfO2/Al gate stack passivated by the dual ozone treatments is reduced by about three orders of magnitude compared to that of a Ge/HfO2/Al gate stack without interface passivation. (semiconductor technology)

  7. Effective interface passivation of a Ge/HfO2 gate stack using ozone pre-gate treatment and ozone ambient annealing

    Zhao Mei; Liang Renrong; Wang Jing; Xu Jun

    2013-01-01

    The physical and electrical properties ofa Ge/GeO2/HfO2/A1 gate stack are investigated.A thin interfacial GeO2 layer (~ 1 nm) is formed between Ge and HfO2 by dual ozone treatments,which passivates the Ge/high-k interface.Capacitors on p-type Ge substrates show very promising capacitance-voltage (C-V) characteristics by using in situ pre-gate ozone passivation and ozone ambient annealing after high-k deposition,indicating efficient passivation of the Ge/HfO2 interface.It is shown that the mid-gap interface state density at the Ge/GeO2 interface is 6.4 × 101 1 cm-2.eV-1.In addition,the gate leakage current density of the Ge/GeO2/HfO2/Al gate stack passivated by the dual ozone treatments is reduced by about three orders of magnitude compared to that ofa Ge/HfO2/Al gate stack without interface passivation.

  8. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    2010-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  9. Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion.

    Bernacchi, Carl J; Leakey, Andrew D B; Kimball, Bruce A; Ort, Donald R

    2011-06-01

    Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O₃]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O₃] on crop ecosystem energy fluxes and water use. Elevated [O₃] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 °C. PMID:21477906

  10. Ozone generation in a kHz-pulsed He-O2 capillary dielectric barrier discharge operated in ambient air

    Sands, Brian L.; Ganguly, Biswa N.

    2013-12-01

    The generation of reactive oxygen species using nonequilibrium atmospheric pressure plasma jet devices has been a subject of recent interest due to their ability to generate localized concentrations from a compact source. To date, such studies with plasma jet devices have primarily utilized radio-frequency excitation. In this work, we characterize ozone generation in a kHz-pulsed capillary dielectric barrier discharge configuration comprised of an active discharge plasma jet operating in ambient air that is externally grounded. The plasma jet flow gas was composed of helium with an admixture of up to 5% oxygen. A unipolar voltage pulse train with a 20 ns pulse risetime was used to drive the discharge at repetition rates between 2-25 kHz. Using UVLED absorption spectroscopy centered at 255 nm near the Hartley-band absorption peak, ozone was detected over 1 cm from the capillary axis. We observed roughly linear scaling of ozone production with increasing pulse repetition rate up to a "turnover frequency," beyond which ozone production steadily dropped and discharge current and 777 nm O(5P→5S°) emission sharply increased. The turnover in ozone production occurred at higher pulse frequencies with increasing flow rate and decreasing applied voltage with a common energy density of 55 mJ/cm3 supplied to the discharge. The limiting energy density and peak ozone production both increased with increasing O2 admixture. The power dissipated in the discharge was obtained from circuit current and voltage measurements using a modified parallel plate dielectric barrier discharge circuit model and the volume-averaged ozone concentration was derived from a 2D ozone absorption measurement. From these measurements, the volume-averaged efficiency of ozone production was calculated to be 23 g/kWh at conditions for peak ozone production of 41 mg/h at 11 kV applied voltage, 3% O2, 2 l/min flow rate, and 13 kHz pulse repetition rate, with 1.79 W dissipated in the discharge.

  11. Responses of a tropical tree species to ozone: visible leaf injury, growth, and lipid peroxidation.

    Cassimiro, Jéssica C; Moraes, Regina M

    2016-04-01

    The Brazilian native tree species Astronium graveolens was indicated as sensitive to ozone in a fumigation experiment. Thus, the objective of this study was to evaluate how sensitive A. graveolens is to ozone under realistic conditions in the field. Eighteen saplings were exposed to ozone in a contaminated area and in a greenhouse with filtered air during two exposure periods of approximately 63 days each (March-May 2012 and September-October 2012). Leaf injury was analyzed by means of its incidence and severity, the leaf injury index (LII) and the progression of leaf abscission. These variables were monitored weekly, whereas growth and lipid peroxidation were monitored monthly. Plants exposed to ozone showed significant growth decrease and visible leaf injury increase, but lipid peroxidation and leaf abscission remained unchanged. These results indicated that plants subjected to ozone possibly diverted energy from growth to the production of antioxidants necessary to cope with ozone-induced oxidative stress. PMID:26780049

  12. A STUDY OF THE POTENTIAL WAYS IN WHICH OZONE COULD REDUCE ROOT GROWTH AND NODULATION OF SOYBEAN

    The possible mechanisms by which the ozone reduces root growth and nodulation of soybean were investigated. Ozone did not appreciably penetrate the plant growth substrates nor did it oxidize soil organic matter to form compounds inhibitory to Rhizobium. When ozone was excluded fr...

  13. Effects of ozone and sulfur dioxide on virus growth in mice.

    Fairchild, G A

    1977-01-01

    Inhalation of ozone and sulfur dioxide inhibited influenza virus growth in the nose of mice. Ozone inhalation caused the more pronounced inhibition of influenza virus growth: 0.6 ppm ozone for 3 hours post-virus exposure almost completely inhibited influenza virus growth in the nose, whereas sulfur dioxide (6 ppm for 7 days) causes only partial inhibition of influenza growth in the nose. Neither gas altered the propagation of influenza virus in the lungs of mice. Vesicular stomatitis virus (VSV) growth was either unaffected by exposure to ozone (0.9 ppm for 3 hours) or, when ozone exposure preceeded VSV exposure, the virus may have grown to slightly higher titer. The inhibitory effect of ozone and sulfur dioxide on influenza virus growth in nasal epithelium suggests a competitive interaction between the chemical inhalant, the virus, and host tissues, with net consequences for the pathogenesis of this disease. If the effcts of these inhalants are to be properly interpreted, they should be determined for all major regions of virus growth and inhalant deposition. PMID:189703

  14. STUDY OF THE INFLUENCE OF OZONE ON THE GROWTH PROCESSES OF MAIZE SEEDS

    Shevchenko A. A.

    2015-01-01

    Full Text Available Increasing the yield of crops is a global challenge substantiated by the scientists from all over the world. To achieve this goal, there are various ways, one of which is the ozonation of seeds before sowing. This method inhibits harmful microflora, which could be formed on the seed during the period of storage, and excites the chemical processes within the seed that can accelerate the process of growth. But despite the positive effect of ozone-air mixture of seeds and a variety of conducting research there is still no reliable data on the technological parameters of ozone effects on seed crops (e.g., corn. In this regard, we have conducted experimental studies to determine the effective parameters of the ozonation of corn seeds, such as the concentration of ozone in the ozone-air mixture, exposure time and binning after treatment. The influence of these parameters was assessed by changes in growth performance of seed, such as germination, germination and growth of strength. Just at the end of the pilot study we carried out a statistical analysis of the data, which allowed us to estimate the degree of influence of each independent parameter (ozone concentration, exposure time, binning after treatment for each dependent parameter (germination energy, germination, growth force. The data obtained is presented in the article

  15. Ambient ozone effects on gas exchange and total non-structural carbohydrate levels in cutleaf coneflower (Rudbeckia laciniata L.) growing in Great Smoky Mountains National Park

    Ozone-sensitive and -tolerant individuals of cutleaf coneflower (Rudbeckia laciniata L.) were compared for their gas exchange characteristics and total non-structural carbohydrates at Purchase Knob, a high elevation site in Great Smoky Mountains National Park, USA. Photosynthesis and stomatal conductance decreased with increased foliar stipple. Sensitive plants had lower photosynthetic rates for all leaves, except the very youngest and oldest when compared to tolerant plants. Stomatal conductance decreased with increasing leaf age, but no ozone-sensitivity differences were found. Lower leaves had less starch than upper ones, while leaves on sensitive plants had less than those on tolerant plants. These results show that ambient levels of ozone in Great Smoky Mountains National Park can adversely affect gas exchange, water use efficiency and leaf starch content in sensitive coneflower plants. Persistence of sensitive genotypes in the Park may be due to physiological recovery in low ozone years. - Highlights: ► Ozone-sensitive and -tolerant cutleaf coneflower (Rudbeckia laciniata L.) were compared. ► Net photosynthesis decreased with increased foliar stipple and leaf age. ► Sensitive plants with visible stipple had lower photosynthetic rates when compared to tolerant plants. ► Stomatal conductance did not differ between sensitivity types. ► Sensitive plants had lower leaf starch content than tolerant plants. - Ambient ozone may cause declines in gas exchange and starch in ozone-sensitive genotypes of cutleaf coneflower.

  16. Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water

    Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O3/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O3/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O3/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

  17. Spatial interpolation of ambient ozone concentrations from sparse monitoring points in Belgium.

    Hooyberghs, Jef; Mensink, Clemens; Dumont, Gerwin; Fierens, Frans

    2006-11-01

    Due to scientific interest on the one hand and political and regulatory obligations on the other hand the monitoring of ozone in the troposphere is an important issue. To this end, in Belgium as in many other countries, a fixed network of monitoring stations is operated. In order to estimate the ozone concentrations over the whole territory, a model is needed to spatially complement the sparse measurements. This paper describes the development of an interpolation scheme which is aimed at fast operational use. The model uses the population density as auxiliary data to remove a spatial trend due to titration by nitric oxide. The residuals are interpolated by kriging. As a benchmark the inverse distance weighting interpolation method is used with and without the detrending. The proposed model systematically improves the interpolation and makes a significant difference when estimating human exposure to ozone. It is generic in design, easy to implement and flexible to changes in the monitoring network. PMID:17075619

  18. Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees

    Olbrich, Maren; Knappe, Claudia; Wenig, Marion; Gerstner, Elke [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Kitao, Mitsutoshi; Matyssek, Rainer [Forest Botany, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Stich, Susanne [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Leuchner, Michael; Werner, Herbert [Bioclimatology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Schlink, Katja; Mueller-Starck, Gerhard [Section of Forest Genetics, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Scherb, Hagen [Institute of Biomathematics and Biometry, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Ernst, Dieter; Heller, Werner [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Bahnweg, Guenther, E-mail: bahnweg@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

  19. Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees

    In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

  20. Cardiac Effects of Seasonal Ambient Particulate Matter and Ozone Co-exposure in Rats

    BackgroundThe potential for seasonal differences in the physicochemical characteristics of ambient particulate matter (PM) to modify interactive effects with gaseous pollutants has not been thoroughly examined. The purpose of this study was to compare cardiac responses in conscio...

  1. Genotypic variation in growth and physiological responses of Finnish hybrid aspen (Populus tremuloides x P. tremula) to elevated tropospheric ozone concentration.

    Oksanen, E; Amores, G; Kokko, H; Amores, J M; Kärenlampi, L

    2001-10-01

    Saplings of six Finnish hybrid aspen (Populus tremuloides Michx. x P. tremula L.) clones were exposed to 0, 50, 100 and 150 ppb ozone (O3) for 32 days in a chamber experiment to determine differences in O3 sensitivity among genotypes. Based on the chamber experiment, three clones with intermediate sensitivity to O3 were selected for a free-air O3 enrichment experiment in which plants were exposed for 2 months to either ambient air (control) or air containing 1.3 x the ambient O3 concentration. We measured stem height and radial growth, number of leaves, dry mass and relative growth rate of leaves, stem and roots, visible leaf injuries, net photosynthesis and stomatal conductance of the clones. There was high clonal variation in susceptibility to O3 in the chamber experiment, indicated by foliar injuries and differential reductions in growth and net photosynthesis. In the free-air O3 enrichment experiment, ozone caused a shift in resource allocation toward stem height growth, thereby altering the shoot to root balance. In both experiments, low O3 concentrations tended to stimulate growth of most clones, whereas 100 and 150 ppb O3 in the chamber experiment impaired growth of most clones. However, growth of the most O3-tolerant clone was not significantly affected by any O3 treatment. PMID:11600339

  2. EPITHELIAL INJURY AND INTERSTITIAL FIBROSIS IN THE PROXIMAL ALVEOLAR REGIONS OF RATS CHRONICALLY EXPOSED TO A SIMULATED PATTERN OF URBAN AMBIENT OZONE

    Electron microscopic morphometry was used to study the development of lung injury during and after chronic (78 weeks) exposure to a pattern of ozone designed to simulate high urban ambient concentrations that occur in some environments. he dolly exposure regimen consisted of a 1 ...

  3. Southwestern Tropical Atlantic coral growth response to atmospheric circulation changes induced by ozone depletion in Antarctica

    Evangelista, H.; Wainer, I.; Sifeddine, A.; Corrège, T.; Cordeiro, R. C.; Lamounier, S.; Godiva, D.; Shen, C.-C.; Le Cornec, F.; Turcq, B.; Lazareth, C. E.; Hu, C.-Y.

    2015-08-01

    Climate changes induced by stratospheric ozone depletion over Antarctica have been recognized as an important consequence of the recently observed Southern Hemisphere atmospheric circulation. Here we present evidences that the Brazilian coast (Southwestern Atlantic) may have been impacted from both winds and sea surface temperature changes derived from this process. Skeleton analysis of massive coral species living in shallow waters off Brazil are very sensitive to air-sea interactions, and seem to record this impact. Growth rates of Brazilian corals show a trend reversal that fits the ozone depletion evolution, confirming that ozone impacts are far reaching and potentially affect coastal ecosystems in tropical environments.

  4. Host location behavior of Cotesia plutellae Kurdjumov (Hymenoptera: Braconidae) in ambient and moderately elevated ozone in field conditions

    In field O3-enrichment experiments increased herbivore densities have been reported, which could be due to negatively affected host location behavior of natural enemies. We addressed the impact of doubling background O3 on the host location of the parasitoid Cotesia plutellae by conducting 24-h trials in an open-air O3-fumigation system during two consecutive years. Two circles (radii 1.40 and 4.00 m) of Plutella xylostella-infested potted cabbage plants were placed in the O3 and ambient plots. Female wasps were released into each plot from the center, and observed 5 times over a 24-h period to assess their host location capability. Thereafter, plants were kept in laboratory conditions until larvae pupation to determine parasitism rates. No significant differences were detected between ambient and O3-enriched environments either in the number of wasps found in the field, or in the percentages of parasitized larvae. This suggests that moderately elevated O3 will not affect the behavior of this parasitoid. - Atmospheric ozone increases do not directly affect the biological control of the cabbage pest, Plutella xylostella

  5. Host location behavior of Cotesia plutellae Kurdjumov (Hymenoptera: Braconidae) in ambient and moderately elevated ozone in field conditions

    Pinto, D.M. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland)], E-mail: delia.pinto@uku.fi; Himanen, S.J. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Nissinen, A. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Agrifood Research Finland, Plant Protection, FIN-31600 Jokioinen (Finland); Nerg, A.-M.; Holopainen, J.K. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland)

    2008-11-15

    In field O{sub 3}-enrichment experiments increased herbivore densities have been reported, which could be due to negatively affected host location behavior of natural enemies. We addressed the impact of doubling background O{sub 3} on the host location of the parasitoid Cotesia plutellae by conducting 24-h trials in an open-air O{sub 3}-fumigation system during two consecutive years. Two circles (radii 1.40 and 4.00 m) of Plutella xylostella-infested potted cabbage plants were placed in the O{sub 3} and ambient plots. Female wasps were released into each plot from the center, and observed 5 times over a 24-h period to assess their host location capability. Thereafter, plants were kept in laboratory conditions until larvae pupation to determine parasitism rates. No significant differences were detected between ambient and O{sub 3}-enriched environments either in the number of wasps found in the field, or in the percentages of parasitized larvae. This suggests that moderately elevated O{sub 3} will not affect the behavior of this parasitoid. - Atmospheric ozone increases do not directly affect the biological control of the cabbage pest, Plutella xylostella.

  6. 78 FR 34964 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...

    2013-06-11

    ... Federal Register on June 6, 2013, (78 FR 34178) and is available at: http://www.epa.gov/air/ozonepollution... on June 6, 2013, (78 FR 34178) and is available at http://www.epa.gov/air/ozonepollution/actions.html... AGENCY 40 CFR Parts 50, 51, 70 and 71 Implementation of the 2008 National Ambient Air Quality...

  7. ambiental

    Roque Leal Salcedo

    2008-01-01

    Full Text Available El derecho internacional ambiental es un conocimiento de carácter transversal, que entre otras consideraciones refleja las preocupaciones de la sociedad por la implementación de un modelo de desarrollo sustentable para el respeto a las reglas del medio natural que garantizan la integridad y renovación de los sistemas naturales. El presente artículo enfoca esta visión a través del análisis de material documental revisado, entre ellos tratados internacionales que permiten distinguir el desarrollo del derecho internacional ambiental y el papel de Organización de las Naciones Unidas (ONU, en el propósito común del derecho individual y colectivo de disfrutar de una vida, un ambiente seguro, sano y ecológicamente equilibrado. En función a estas disertaciones las consideraciones finales exponen parte de la visión que ha estructurado la ONU y que representan un aporte considerable en el fomento de la conciencia mundial sobre la necesidad de establecer vínculos entre las naciones para el continuo desarrollo de esta rama del derecho.

  8. Effects of ozone on growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat (Triticum aestivum L.)

    Akhtar, Nahid [United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Yamaguchi, Masahiro; Inada, Hidetoshi; Hoshino, Daiki; Kondo, Taisuke [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Izuta, Takeshi, E-mail: izuta@cc.tuat.ac.j [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

    2010-05-15

    To clarify the effects of O{sub 3} on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O{sub 3} at 60 and 100 nl l{sup -1} (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O{sub 3}. Although there was no significant effect of O{sub 3} on stomatal diffusive conductance to H{sub 2}O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O{sub 3.} The sensitivity of growth, yield, yield components and leaf gas exchange rates to O{sub 3} was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O{sub 3} may detrimentally affect wheat production in Bangladesh. - The exposure to ambient levels of ozone decreases growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat.

  9. Effects of ozone on growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat (Triticum aestivum L.)

    To clarify the effects of O3 on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O3 at 60 and 100 nl l-1 (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O3. Although there was no significant effect of O3 on stomatal diffusive conductance to H2O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O3. The sensitivity of growth, yield, yield components and leaf gas exchange rates to O3 was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O3 may detrimentally affect wheat production in Bangladesh. - The exposure to ambient levels of ozone decreases growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat.

  10. Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, growth, and nutrient concentrations of young beech trees (Fagus sylvatica)

    Thomas, V.F.D. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)]. E-mail: vera.thomas@iap.ch; Braun, S. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland); Flueckiger, W. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)

    2006-09-15

    Beech seedlings were grown under different nitrogen fertilisation regimes (0, 20, 40, and 80 kg N ha{sup -1} yr{sup -1}) for three years and were fumigated with either charcoal-filtered (F) or ambient air (O{sub 3}). Nitrogen fertilisation increased leaf necroses, aphid infestations, and nutrient ratios in the leaves (N:P and N:K), as a result of decreased phosphorus and potassium concentrations. For plant growth, biomass accumulation, and starch concentrations, a positive nitrogen effect was found, but only for fertilisations of up to 40 kg N ha{sup -1} yr{sup -1}. The highest nitrogen load, however, reduced leaf area, leaf water content, growth, biomass accumulation, and starch concentrations, whereas soluble carbohydrate concentrations were enhanced. The ozone fumigation resulted in reduced leaf area, leaf water content, shoot growth, root biomass accumulation, and decreased starch, phosphorus, and potassium concentrations, increasing the N:P and N:K ratios. A combined effect of the two pollutants was detected for the leaf area and the shoot elongation, where ozone fumigation amplified the nitrogen effects. - The effects of nitrogen and ozone on growth, carbohydrate concentrations, and nutrients are mainly additive.

  11. Development of an ozone high sensitive sensor working at ambient temperature

    Hybrid SnO2/SWNTs thin layer were deposited by using sol-gel process. Such sensitive layers showed very high performances for O3 flow detection at ambient temperature. Limit sensitivity, lower than 21,5 ppb of O3 in air has been reached by using these hybrid layers. Compared to usefull metal oxide sensors, the main advantage of the use of such hybrid layers, is that these devices enable the detection of O3 traces at room temperature. The influence of sensor's working temperature is discussed and finally a reactional mechanism for the detection of O3 is proposed.

  12. Differential protection of ethylenediurea (EDU) against ambient ozone for five cultivars of tropical wheat

    The antiozonant EDU (ethylenediurea) was used to assess the impact of ambient O3 under field conditions on five cultivars of tropical wheat (Triticum aestivum L.). EDU solution (0 ppm and 400 ppm) was applied as soil drench (100 ml plant-1) 10 days after germination (DAG) at an interval of 12 days. EDU-treated plants showed significant increments in stomatal conductance, photosynthetic rate, variable fluorescence, total chlorophyll, ascorbic acid, proline and protein contents and protective enzymes (POX, SOD and APX) activities in HUW468, HUW510 and HUW234 cultivars, while, a reverse trend was observed for lipid peroxidation. EDU application restored grain yield significantly by maintaining higher levels of antioxidants, metabolites and enzymes in cultivars HUW468 and HUW510. Sonalika and PBW343 showed least response of measured parameters under EDU treatment suggesting their greater resistance to O3. EDU, thus proved its usefulness in screening suitable wheat cultivars for areas experiencing elevated concentrations of O3. - EDU successfully screened the sensitivity of tropical wheat cultivars to ambient O3 under natural field conditions.

  13. Differential protection of ethylenediurea (EDU) against ambient ozone for five cultivars of tropical wheat

    Singh, Shalini [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, S.B., E-mail: sbagrawal56@gmail.co [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, Madhoolika [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)

    2009-08-15

    The antiozonant EDU (ethylenediurea) was used to assess the impact of ambient O{sub 3} under field conditions on five cultivars of tropical wheat (Triticum aestivum L.). EDU solution (0 ppm and 400 ppm) was applied as soil drench (100 ml plant{sup -1}) 10 days after germination (DAG) at an interval of 12 days. EDU-treated plants showed significant increments in stomatal conductance, photosynthetic rate, variable fluorescence, total chlorophyll, ascorbic acid, proline and protein contents and protective enzymes (POX, SOD and APX) activities in HUW468, HUW510 and HUW234 cultivars, while, a reverse trend was observed for lipid peroxidation. EDU application restored grain yield significantly by maintaining higher levels of antioxidants, metabolites and enzymes in cultivars HUW468 and HUW510. Sonalika and PBW343 showed least response of measured parameters under EDU treatment suggesting their greater resistance to O{sub 3}. EDU, thus proved its usefulness in screening suitable wheat cultivars for areas experiencing elevated concentrations of O{sub 3}. - EDU successfully screened the sensitivity of tropical wheat cultivars to ambient O{sub 3} under natural field conditions.

  14. Physiological and foliar symptom response in the crowns of Prunus serotina, Fraxinus americana and Acer rubrum canopy trees to ambient ozone under forest conditions

    The crowns of five canopy dominant black cherry (Prunus serotina Ehrh.), five white ash (Fraxinus americana L.), and six red maple (Acer rubrum L.) trees on naturally differing environmental conditions were accessed with scaffold towers within a mixed hardwood forest stand in central Pennsylvania. Ambient ozone concentrations, meteorological parameters, leaf gas exchange and leaf water potential were measured at the sites during the growing seasons of 1998 and 1999. Visible ozone-induced foliar injury was assessed on leaves within the upper and lower crown branches of each tree. Ambient ozone exposures were sufficient to induce typical symptoms on cherry (0-5% total affected leaf area, LAA), whereas foliar injury was not observed on ash or maple. There was a positive correlation between increasing cumulative ozone uptake (U) and increasing percent of LAA for cherry grown under drier site conditions. The lower crown leaves of cherry showed more severe foliar injury than the upper crown leaves. No significant differences in predawn leaf water potential (ψL) were detected for all three species indicating no differing soil moisture conditions across the sites. Significant variation in stomatal conductance for water vapor (gwv) was found among species, soil moisture, time of day and sample date. When comparing cumulative ozone uptake and decreased photosynthetic activity (Pn), red maple was the only species to show higher gas exchange under mesic vs. drier soil conditions (P wv and Pn demonstrate the strong influence of heterogeneous environmental conditions within forest canopies. - Within the heterogeneous environment of a mature forest, many factors in addition to soil moisture play a significant role in determining exposure/response relationships to ozone

  15. EFFECTS OF OZONE ON SPORULATION, SPORE GERMINATION, AND GROWTH OF FOMES ANNOSUS

    Effects of ozone (O3) on certain cultural characteristics of Fomes annosus were investigated in exposure chamber studies. Growth rates of F. annosus decreased and conidial germ tubes were shorter and had fewer branches as O3 dosages increased. F. annosus conidial production was v...

  16. Did the Ambient Ozone Affect Stem Increment of Scots Pines (Pinus sylvestris L.) on Territories under Regional Pollution Load? Step III of Lithuanian Studies

    Algirdas Augustaitis; Ingrida Augustaitiene; Gintautas Cinga; Juozapas Mazeika; Romualdas Deltuvas; Romualdas Juknys; Adomas Vitas

    2007-01-01

    This study aimed to explore if changes in stem increment of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone concentration when the impact of tree dendrometric parameters (age, diameter) and crown defoliation are accounted for. More than 200 dominant and codominant trees from 12 pine stands, for which crown defoliation had been assessed since 1994, were chosen for increment boring and basal area increment computing. Stands are located in Lithuanian national parks...

  17. Ambient Ozone Control in a Photochemically Active Region: Short-Term Despiking or Long-Term Attainment?

    Ou, Jiamin; Yuan, Zibing; Zheng, Junyu; Huang, Zhijiong; Shao, Min; Li, Zekun; Huang, Xiaobo; Guo, Hai; Louie, Peter K K

    2016-06-01

    China has made significant progress decreasing the ambient concentrations of most air pollutants, but ozone (O3) is an exception. O3 mixing ratios during pollution episodes are far higher than the national standard in the Pearl River Delta (PRD), thus greater evidence-based control efforts are needed for O3 attainment. By using a validated O3 modeling system and the latest regional emission inventory, this study illustrates that control strategies for short-term O3 despiking and long-term attainment in the PRD may be contradictory. VOC-focused controls are more efficient for O3 despiking in urban and industrial areas, but significant NOx emission reductions and a subsequent transition to a NOx-limited regime are required for O3 attainment. By tracking O3 changes along the entire path toward long-term attainment, this study recommends to put a greater focus on NOx emission controls region-wide. Parallel VOC reductions around the Nansha port are necessary in summertime and should be extended to the urban and industrial areas in fall with a flexibility to be strengthened on days forecasted to have elevated O3. Contingent VOC-focused controls on top of regular NOx-focused controls would lay the groundwork for striking a balance between short-term despiking and long-term attainment of O3 concentrations in the PRD. PMID:27135547

  18. STUDY OF THE INFLUENCE OF OZONE ON THE GROWTH PROCESSES OF MAIZE SEEDS

    Shevchenko A. A.; Saprunova E. A.

    2015-01-01

    Increasing the yield of crops is a global challenge substantiated by the scientists from all over the world. To achieve this goal, there are various ways, one of which is the ozonation of seeds before sowing. This method inhibits harmful microflora, which could be formed on the seed during the period of storage, and excites the chemical processes within the seed that can accelerate the process of growth. But despite the positive effect of ozone-air mixture of seeds and a variety of conducting...

  19. Effect of increased carbon dioxide concentrations on stratospheric ozone

    During the past several years, much attention has been focused on the destruction of ozone by anthropogenic pollutants such as the nitrogen oxides and chlorofluoromethane. Little or no attention has been given to the influence on ozone of an increased carbon dioxide concentration for which a measurable growth has been observed. Increased carbon dioxide can directly affect ozone by perturbing atmospheric temperatures, which will alter ozone production, whose rate displays a fairly strong temperature dependence. This paper presents one-dimensional model results for the steady state ozone behavior when the CO2 concentration is twice its ambient level which account for coupling between chemistry and temperature. When the CO2 level doubled, the total ozone burden increased in relation to the ambient burden by 1.2--2.5%, depending on the vertical diffusion coefficient used. Above 30 km. In this region the relation variations were insensitive to the choice of diffusion coefficient. Below 30 km, ozone concentrations were smaller than the unperturbed values and were sensitive to the vertical diffusion profile in this region (10--30 km). Ozone decreases in the lower stratosphere because of a reduction in ozone-producing solar radiation, which results in smaller downward ozone fluxes from the region at 25--30 km relative to the flux values for the ambient atmosphere. These offsetting changes occurring in the upper and lower stratosphere act to minimize the variation in total ozone

  20. 75 FR 1566 - Public Hearings for Reconsideration of the 2008 National Ambient Air Quality Standards for Ozone

    2010-01-12

    ... the following Web site: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_fr.html for the addresses.../standards/ozone/s_o3_cr_fr.html . FOR FURTHER INFORMATION CONTACT: If you would like to speak at the public... proposal at http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_fr.html prior to the hearings....

  1. Influence of growth ambient on the surface and structural properties of vanadium oxide nanorods

    Tien, Li-Chia; Chen, Yu-Jyun

    2013-06-01

    The influence of growth ambient on the surface and structural properties of vanadium oxide nanorods have been studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS). The vanadium oxide nanorods, which were synthesized through an ambient controlled vapor transport process, exhibit different surface electronic properties depending upon the growth ambient. The Raman data indicates that the as-grown samples are orthorhombic V2O5 phase with a small variation of stoichiometry. Under highly oxidative conditions, nearly stoichiometry sample can be grown. If the samples were grown under less oxidizing conditions, an increase of structural disorder was observed. The observed V 2p core level spectra of both samples showed a single peak with chemical shifts corresponding to the V5+ and V4+. XPS results suggested that the highly oxidized vanadium ions (V5+) are gradually reduced to lower oxidation state (V4+) with the decreases of ambient oxygen levels during growth. The results clearly show that surface non-stoichiometry may be correlated with structural disorder of V2O5 nanorods. The growth ambient and post-annealing may influence the vanadium oxidation state and subsequent surface reactivity significantly.

  2. Evaluation of innovative air-monitoring technologies for the measurement of ambient concentrations of ozone and its precursors at the 1996 Summer Olympics

    Gamiles, Donald S.; Rodgers, Michael; Meeker, Charles; Olive, Brent S.; Simpson, Orman A.

    1997-05-01

    An open path Fourier transform IR spectrometer and an ultra- violet differential optical absorption spectrometer were used during the 1996 Atlanta Olympics games to monitor for ambient ozone and its precursors near the Olympic Village. Both systems were operated continuously before, during, and after the increase in Atlanta's population associated with the Summer games. The study utilized the massive changes in population patterns to observe and measure changes in local air quality due to an increased local population. A second goal of the program was to evaluate both open path instruments in continuous field use over a period of several weeks. The evaluation included the following criteria: instrumentation operability, system precision and accuracy, detection capability, and over-all ease of use. Both open path systems selected and measured ambient levels of ozone. A limited number of ozone precursors were detected. The study was sponsored by the Georgia Institute of Technology's Air Quality Laboratory, the US Department of Energy, and the US Environmental Protection Agency.

  3. Factors affecting the effects of EDU on growth and yield of field-grown bush beans (Phaseolus vulgaris L.), with varying degrees of sensitivity to ozone

    Elagoez, Vahram [Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003 (United States)]. E-mail: velagoz@nsm.umass.edu; Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003 (United States)

    2005-08-15

    The effects of foliar applications of ethylenediurea (EDU) on responses to ozone by field-grown bush bean (Phaseolus vulgaris L.) lines 'S156' (O{sub 3}-sensitive) and 'R123' (O{sub 3}-tolerant), and cultivars 'BBL 290' (O{sub 3}-sensitive) and 'BBL 274' (O{sub 3}-tolerant) were investigated during the 2001 and 2002 growing seasons. EDU was applied weekly to designated plants between primary leaf expansion and pod senescence. Results were compared with control plants at harvests made at pod maturation and pod senescence. In 2001, average hourly ambient O{sub 3} concentrations ranged between 41 and 59 ppb for a total of 303 h; in 2002, for 355 h. EDU applications prior to pod maturation significantly increased the number of marketable pods in 'R123', but not for the other cultivars. Harvests at pod senescence showed significant improvements in crop yield production in EDU-treated 'S156' plants, whereas for EDU-treated 'R123' plants significant reductions were determined in above-ground biomass and seed production. In contrast, results from 'BBL 290' and 'BBL 274' at both harvest points were inconclusive. Growth and reproductive responses of O{sub 3}-sensitive and O{sub 3}-tolerant bush bean plants to EDU applications varied, depending on developmental stages, duration of EDU applications, and fluctuations in ambient O{sub 3}. - Plant sensitivity to ozone, stage of plant development, number of applications of EDU and ambient ozone affect bean plant responses to EDU.

  4. Changes in the Community of Ectomycorrhizal Fungi and Increased Fine Root Number Under Adult Beech Trees Chronically Fumigated with Double Ambient Ozone Concentration

    Grebenc, Tine; Kraigher, Hojka

    2007-01-01

    Forest soils are an important but under-studied part of forest ecosystems. The effects of O3 on below-ground processes in a mature forest have only received limited attention so far. In our study, we have analysed the community of ectomycorrhizal fungi and beech fine root dynamics over two growing seasons (2003–2004) in a 70-year old mixed spruce-beech forest stand, in which two groups of five adult beech trees were either fumigated by 2 × ambient ozone concentration or used as control. The m...

  5. The Influence of Ozonization For DO, BOD and Bacterial Growth in The Liquid Waste From Tanning Leather Industry

    The research of ozonization influence of dissolved oxygen (DO), biological oxygen demand (BOD) and the bacterial growth in the liquid waste from tanning leather industry has been done. The objectives of this research was to studied the influence of ozonization for decomposition process of the organic compound in these waste by indicator of BOD decreased, increased of DO and decomposer bacterial growth. The ozonization was carried out by time variation 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195 and 210 minutes. Each samples of the waste has been ozonized keep in the sterile reaction tube for isolated of bacterial and the other keep in the bottle for BOD and DO measurement. These research results show that ozonization with 16.243 x 10-4 mg/second debit for 3 hours can decreased of BOD were 19.61 %, and ozonization for 3.5 hours can increased of DO were 82.5%. The other hand, 3 hours ozonization can decreased of kind of bacterial growth were 80 %. (author)

  6. Inhibitory effects of ambient levels of solar UV-A and UV-B radiation on growth of cucumber

    The influence of solar UV-A and UV-B radiation at Beltsville, Maryland, on growth and flavonoid content in four cultivars of Cucumis sativus L. (Ashley, Poinsett, Marketmore, and Salad Bush cucumber) was examined during the summers of 1994 and 1995. Plants were grown from seed in UV exclusion chambers consisting of UV-transmitting Plexiglas, lined with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or cellulose acetate to transmit UV-A and UV-B. Despite previously determined differences in sensitivity to supplemental UV-B radiation, all four cultivars responded similarly to UV-B exclusion treatment. After 19–21 days, the four cultivars grown in the absence of solar UV-B (polyester) had an average of 34, 55, and 40% greater biomass of leaves, stems, and roots, respectively, 27% greater stem height, and 35% greater leaf area than those grown under ambient UV-B (cellulose acetate). Plants protected from UV-A radiation as well (Llumar) showed an additional 14 and 22% average increase, respectively, in biomass of leaves and stems, and a 22 and 19% average increase, respectively, in stem elongation and leaf area over those grown under polyester. These findings demonstrate the extreme sensitivity of cucumber not only to present levels of UV-B but also to UV-A and suggest that even small changes in ozone depletion may have important biological consequences for certain plant species. (author)

  7. Ideas and perspectives: Southwestern tropical Atlantic coral growth response to atmospheric circulation changes induced by ozone depletion in Antarctica

    Evangelista, Heitor; Wainer, Ilana; Sifeddine, Abdelfettah; Corrège, Thierry; Cordeiro, Renato C.; Lamounier, Saulo; Godiva, Daniely; Shen, Chuan-Chou; Le Cornec, Florence; Turcq, Bruno; Lazareth, Claire E.; Hu, Ching-Yi

    2016-04-01

    Recent Southern Hemisphere (SH) atmospheric circulation, predominantly driven by stratospheric ozone depletion over Antarctica, has caused changes in climate across the extratropics. Here, we present evidence that the Brazilian coast (southwestern Atlantic) may have been impacted from both wind and sea-surface temperature changes derived from this process. Skeleton analysis of massive coral species living in shallow waters off Brazil are very sensitive to air-sea interactions, and seem to record this impact. Growth rates of Brazilian corals show a trend reversal that fits the ozone depletion evolution, confirming that ozone impacts are far reaching and potentially affect coastal ecosystems in tropical environments.

  8. Mycorrhizal status of an ozone-sensitive poplar clone treated with the antiozonant ethylene diurea

    Katanić, Marina; Paoletti, Elena; Orlović, Saša; Grebenc, Tine; Kraigher, Hojka

    2014-01-01

    The antiozonant ethylene diurea is proven to prevent growth reductions in forest trees induced by ozone. The community of mycorrhizal fungi could be useful indicator of environmental stress. In this study, response of mycorrhizal fungi and fine roots to a 4-year exposure to ambient ozone and treatment with antiozonant was investigated in ozone-sensitive poplar clone under field conditions. The community of ectomycorrhizal fungi and root length colonization with ectomycorrhizal, arbuscular myc...

  9. Growth, radiation use efficiency, and canopy reflectance of wheat and corn grown under elevated ozone and carbon dioxide atmosphere

    Estimates of increases in future agricultural production in response to increases in carbon dioxide (CO2) concentrations in the atmosphere are often based on the beneficial physiological effect of CO2 enrichment on plant growth, especially in Ca plants. However, these estimates fail to consider the negative impact of ozone (O3) air pollution on crop production. Increases in tropospheric concentrations of both gases, CO2 and O3, have been observed over the past century, and both are predicted to continue to increase at even higher rates in the near future to levels when they may have a significant impact on agricultural production. Field studies with wheat (Friticum aestivum L.) in 1991 and 1992, and corn (Zea mays L.) in 1991 were conducted using open-top chambers to mimic atmospheric concentrations of CO2 (~ 500 μL-1 CO2) and Oa (- 40 nL L-1 O3 above ambient air [O3] during 7 h day- 1, 5 days week-1) that are predicted to occur at the Earth's surface during the first half of the 21st century. Wheat and corn (C3 vs. C4) produced clearly different responses to CO2 enrichment, but similar responses to O3 exposure. In wheat, O3 exposure led to reduced grain yield, biomass, and radiation use efficiency (RUE, phytomass production per unit of energy received); in both years; but reduction in accumulated absorbed photosynthetically active radiation (AAPAR) was observed only in 1991. Conversely, CO2 enrichment produced greater grain yield, dry biomass, and RUE. With CO2 enrichment, the Oa-induced stress to wheat plants was apparently ameliorated since responses were equivalent to the control group (low O3 and ambient CO2) for all variables. In contrast, corn demonstrated no benefit to CO2 enrichment for measured variables, and corn grain yield was the only parameter negatively influenced by O3 exposure that is attributed to O3-induced damage during the flowering process. Additionally, no treatment differences were observed for leaf area index (LAI) as determined

  10. Photochemical model evaluation of the ground-level ozone impacts on ambient air quality and vegetation health in the Alberta oil sands region: Using present and future emission scenarios

    Vijayaraghavan, Krish; Cho, Sunny; Morris, Ralph; Spink, David; Jung, Jaegun; Pauls, Ron; Duffett, Katherine

    2016-09-01

    One of the potential environmental issues associated with oil sands development is increased ozone formation resulting from NOX and volatile organic compound emissions from bitumen extraction, processing and upgrading. To manage this issue in the Athabasca Oil Sands Region (AOSR) in northeast Alberta, a regional multi-stakeholder group, the Cumulative Environmental Management Association (CEMA), developed an Ozone Management Framework that includes a modelling based assessment component. In this paper, we describe how the Community Multi-scale Air Quality (CMAQ) model was applied to assess potential ground-level ozone formation and impacts on ambient air quality and vegetation health for three different ozone precursor cases in the AOSR. Statistical analysis methods were applied, and the CMAQ performance results met the U.S. EPA model performance goal at all sites. The modelled 4th highest daily maximum 8-h average ozone concentrations in the base and two future year scenarios did not exceed the Canada-wide standard of 65 ppb or the newer Canadian Ambient Air Quality Standards of 63 ppb in 2015 and 62 ppb in 2020. Modelled maximum 1-h ozone concentrations in the study were well below the Alberta Ambient Air Quality Objective of 82 ppb in all three cases. Several ozone vegetation exposure metrics were also evaluated to investigate the potential impact of ground-level ozone on vegetation. The chronic 3-months SUM60 exposure metric is within the CEMA baseline range (0-2000 ppb-hr) everywhere in the AOSR. The AOT40 ozone exposure metric predicted by CMAQ did not exceed the United Nations Economic Commission for Europe (UN/ECE) threshold of concern of 3000 ppb-hr in any of the cases but is just below the threshold in high-end future emissions scenario. In all three emission scenarios, the CMAQ predicted W126 ozone exposure metric is within the CEMA baseline threshold of 4000 ppb-hr. This study outlines the use of photochemical modelling of the impact of an industry (oil

  11. Linking changes in ozone to changes in emissions and meteorology

    Estimation of trends in ozone air quality is a complex problem because of the strong influence of meteorology on ozone and its precursors. In this paper we present a physically-consistent methodology to link changes in ozone to changes in precursor emissions in the presence of meteorological fluctuations. Time series ozone concentrations (O3), nitrogen oxides (NOx) and non-methane hydrocarbons (NMHC) measured from 1985 to 1993 in the Los Angeles Air Basin are first separated into different time scales using the Kolmogorov-Zurbenko (KZ) filter. Linear regression analysis is performed on meteorological variables and ozone and its precursors on each time scale. The downward trend in the daily hourly maxima of O3 is about twice that in the daily hourly mean O3. The results demonstrate that emission control programs implemented over Southern California were very effective in improving ambient ozone levels during a period of robust economic growth. (Author)

  12. Growth of β-Ga2O3 single crystals using vertical Bridgman method in ambient air

    Hoshikawa, K.; Ohba, E.; Kobayashi, T.; Yanagisawa, J.; Miyagawa, C.; Nakamura, Y.

    2016-08-01

    A new approach to β-Ga2O3 single crystal growth was studied, using the vertical Bridgman (VB) method in ambient air, while measuring the β-Ga2O3 melting temperature and investigating the effects of crucible composition and shape. β-Ga2O3 single crystals 25 mm in diameter were grown in platinum-rhodium alloy crucibles in ambient air, with no adhesion of the crystals to the crucible wall. Single crystal growth without a crystal seed was realized by (100) faceted growth with a growth direction perpendicular to the (100) faceted plane.

  13. Vertical and Horizontal Measurements of Ambient Ozone over a Gas and Oil Production Area using a UAV Platform

    Jensen, A.; Gowing, I.; Martin, R. S.

    2013-12-01

    During the 2013 wintertime Uintah Basin Ozone Study (UBOS13), an autonomous unmanned aerial vehicle (UAV) platform, coupled with an on-board UV ozone monitor, flew several spatial profiles near the location (Horse Pool) of other concentrated measurements by other co-investigators. The airframe, part of the Utah Water Research Laboratory's (UWRL) AggieAir UAV program, consisted of a custom-built, battery-operated plane with and 2.4 m (8 ft) wing span and a 12.7 cm x 12.7 cm x 30.5 cm payload bay with a carrying capacity of approximately 2.0 kg. With the current power system, the fully-loaded AggieAir UAV can fly for approximately 45 minutes at a nominal airspeed of 13.4 m/s (30 mph). The system can be operated either in manual control or be flown autonomously following preprogrammed waypoints via a built in GPS system. The AggieAir UAV systems were primarily designed for photographic and telemetry tracking projects. For the UBOS13 flights, a 2B Technologies Model 205 Ozone (O3) monitor was modified for minimal weight optimization, wrapped with lightweight insulation and secured into the UAV payload bay. Additionally, HOBO Model H08-001-02 shielded temperature/datalogger was secured to the exterior of the UAV from parallel thermal profile determination. During the study period, three demonstration flight profiles were obtained on February 17 and 18, 2013: two vertical 'curtain' profiles and a pair of 'stacked' horizontal profiles. As recorded by numerous ground-based monitoring sites, the ozone during the UAV test periods was characterized by initial trends of daytime O3 maximums over 130 ppb, followed by a meteorological front partially ventilating the Basin on the evening of Feb. 17th leading to decreased O3 minimums around 40 ppb. However, the ground level O3 rebuilt quickly to ground level maximums approaching 100 ppb. The vertical 'curtain' flown on the evening of Feb. 17th only reached a maximum elevation of about 2160 m ASL (600 m AGL) due to encountering

  14. Ozone affects growth and development of Pieris brassicae on the wild host plant Brassica nigra

    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

  15. Gas exchange and chlorophyll fluorescence of pea (Pisum sativum L.) plants in response to ambient ozone at a rural site in Egypt

    Egyptian pea cultivars (Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top chambers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009–2013) at a rural site in northern Egypt. Net photosynthetic rates (PN), stomatal conductance (gs), intercellular CO2 (Ci) and chlorophyll fluorescence were measured. Ozone (O3) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation. PN of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cultivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O3. The maximum impairment in PN was recorded in the cultivar Victory (46%) in 2013 when the highest O3 levels were recorded (90 nL L−1). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between PN and Ci, indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The PN vs. Ci curves were fitted to a non-rectangular hyperbolic model. The actual quantum yield (ΦPSII) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively. - Highlights: • Ozone (O3) concentrations recorded were within the ranges of phytotoxicity. • O3 has a clear influence on the physiological parameters. • O3 decreased Photosynthetic rates, chlorophyll fluorescence parameters. • The

  16. Effects of elevated carbon dioxide and ozone on the growth and yield of potatoes (Solanum tuberosum) grown in open-top chambers

    Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 μmol mol-1 CO2) and two ozone concentrations (ambient and an 8 h day -1 seasonal mean of 50 nmol mol-1 O3) between emergence and final harvest. Periodic non-destructive measurements were made and destructive harvests were carried out at three key developmental stages (24, 49 and 101 days after emergence) to establish effects on growth and tuber yield. Season-long exposure to elevated O3 reduced above-ground dry weight at final harvest by 8.4% (P2 and O3 for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO2 on plant height, leaf number or green leaf area ratio. However, destructive harvests at tuber initiation and 500 deg Cd after emergence showed that above-ground dry weight (8 and 7% respectively) and tuber yield (88 and 44%) were significantly increased (P-1 CO2 treatment. Responses to 550 and 680 μmol mol-1 CO2 were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO2 enrichment. Significant effects on the above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P2, particularly in the smaller size categories. The results show that the O3 treatment imposed was insufficient to reduce tuber yields and that, although elevated CO2 enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. (Author)

  17. Study of ozone gas formed in the industrial radiation process with cobalt-60 and its impact on the environment; Estudo sobre o gas ozonio formado no processo de irradiacao industrial com cobalto-60 e seu impacto no meio ambiente

    Uzueli, Daniel Henrique

    2013-07-01

    The radiation processing is present in various products such as foods, medical disposable, electrical cables, gems, among others. This process aims to improve the properties, sterilize or sanitize irradiated products. In industrial irradiators facilities, electromagnetic radiation (gamma and X-rays) or electrons before they interact with the products in processing, there are a layer of air. To interact with this air layer, it causes radiolytic effects on the molecules present in the ambient atmosphere, and the main interaction are with the oxygen molecules that have their bonds broken, separating them into two highly reactive atoms that recombine with the other molecule of oxygen to form ozone gas. In this work it was studied the formation, decay and dispersion of ozone in industrial gamma irradiators facilities that use cobalt-60 as a source of radiation. The monitoring of ozone concentration was performed by optical absorption method in a commercial monitor. (author)

  18. Future impacts of distributed power generation on ambient ozone and particulate matter concentrations in the San Joaquin Valley of California.

    Vutukuru, Satish; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald

    2011-12-01

    Distributed power generation-electricity generation that is produced by many small stationary power generators distributed throughout an urban air basin-has the potential to supply a significant portion of electricity in future years. As a result, distributed generation may lead to increased pollutant emissions within an urban air basin, which could adversely affect air quality. However, the use of combined heating and power with distributed generation may reduce the energy consumption for space heating and air conditioning, resulting in a net decrease of pollutant and greenhouse gas emissions. This work used a systematic approach based on land-use geographical information system data to determine the spatial and temporal distribution of distributed generation emissions in the San Joaquin Valley Air Basin of California and simulated the potential air quality impacts using state-of-the-art three-dimensional computer models. The evaluation of the potential market penetration of distributed generation focuses on the year 2023. In general, the air quality impacts of distributed generation were found to be small due to the restrictive 2007 California Air Resources Board air emission standards applied to all distributed generation units and due to the use of combined heating and power. Results suggest that if distributed generation units were allowed to emit at the current Best Available Control Technology standards (which are less restrictive than the 2007 California Air Resources Board standards), air quality impacts of distributed generation could compromise compliance with the federal 8-hr average ozone standard in the region. PMID:22263420

  19. Responses of selected birch (Betula pendula Roth) clones to ozone change over time.

    Oksanen, E.

    2003-06-01

    A long-term free air ozone fumigation experiment was conducted to study changes in physiological ozone responses during tree ontogeny and exposure time in ozone sensitive and tolerant clones of European white birch (Betula pendula Roth), originated from south and central Finland. The trees were grown in soil in natural microclimatic conditions under ambient ozone (control) and 1.4-1.7 x ambient (elevated) ozone from May 1996 to October 2001, and were measured for stem and foliage growth, net photosynthesis, stomatal conductance, stomatal density, visible injuries, foliar starch content and bud formation. After 6 years of exposure, the magnitude of ozone-induced growth reductions in the sensitive clone was 12-48% (significant difference), levels similar or greater than those reported earlier for 2- and 3-year-old saplings undergoing shorter exposures. In the tolerant clone, growth of these larger trees was reduced by 1-38% (significant difference in stem volume), although the saplings had previously been unaffected. In both clones, ozone stress led to significantly reduced leaf-level net photosynthesis but significantly increased stomatal conductance rates during the late summer, resulting in a lower carbon gain for bud formation and the onset of visible foliar injuries. Increasing ozone sensitivity with duration of exposure was explained by a change in growth form (relatively reduced foliage mass), a lower photosynthesis to stomatal conductance ratio during the late summer, and deleterious carry-over effects arising from the reduced number of over-wintering buds. PMID:12803615

  20. Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms

    We studied the effects of relatively low levels of O3 (40-50 ppb) and CO2-enrichment (+ 100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O3. However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO2 did not amend the detrimental effects of O3 on aboveground biomass. Elevated CO2 alone had only minor effects. An O3-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem. - Species- and parameter-specific differences found in O3 responses and CO2 amelioration in wild plants under competitive environment

  1. Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms

    Raemoe, Kaisa [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland)]. E-mail: kaisa.koivisto@helsinki.fi; Kanerva, Teri [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland); Nikula, Suvi [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland); Ojanperae, Katinka [MTT, Agrifood Research Finland, Environmental Research, 31600 Jokioinen (Finland); Manninen, Sirkku [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland)

    2006-11-15

    We studied the effects of relatively low levels of O{sub 3} (40-50 ppb) and CO{sub 2}-enrichment (+ 100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O{sub 3}. However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO{sub 2} did not amend the detrimental effects of O{sub 3} on aboveground biomass. Elevated CO{sub 2} alone had only minor effects. An O{sub 3}-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem. - Species- and parameter-specific differences found in O{sub 3} responses and CO{sub 2} amelioration in wild plants under competitive environment.

  2. Growth and nutritive quality of Poa pratensis as influenced by ozone and competition

    Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O3) stress. A phytometer-based approach was utilized to investigate O3 effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species (Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000-2002 to charcoal-filtered air + 25 ppb O3 (control) or non-filtered air + 50 ppb O3 (elevated O3). Biomass production was not affected by O3, but foliar injury symptoms were observed in May 2002. Early-season O3 exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O3 was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O3 exposure. - Early-season O3 exposure decreased nutritive quality of Poa pratensis, and nutritive quality response to O3 was not altered by interspecific competition

  3. Growth and nutritive quality of Poa pratensis as influenced by ozone and competition

    Bender, J. [Institute of Agroecology, Federal Agricultural Research Centre (FAL), Bundesallee 50, 38116 Braunschweig (Germany)]. E-mail: juergen.bender@fal.de; Muntifering, R.B. [Department of Animal Sciences, Auburn University, AL 36849 (United States); Lin, J.C. [Department of Animal Sciences, Auburn University, AL 36849 (United States); Weigel, H.J. [Institute of Agroecology, Federal Agricultural Research Centre (FAL), Bundesallee 50, 38116 Braunschweig (Germany)

    2006-07-15

    Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O{sub 3}) stress. A phytometer-based approach was utilized to investigate O{sub 3} effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species (Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000-2002 to charcoal-filtered air + 25 ppb O{sub 3} (control) or non-filtered air + 50 ppb O{sub 3} (elevated O{sub 3}). Biomass production was not affected by O{sub 3}, but foliar injury symptoms were observed in May 2002. Early-season O{sub 3} exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O{sub 3} was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O{sub 3} exposure. - Early-season O{sub 3} exposure decreased nutritive quality of Poa pratensis, and nutritive quality response to O{sub 3} was not altered by interspecific competition.

  4. Gas exchange and chlorophyll fluorescence of pea (Pisum sativum L.) plants in response to ambient ozone at a rural site in Egypt

    Ismail, I.M.; Basahi, J.M. [Air Pollution Laboratory (APL), Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, P. O. Box 80216, Jeddah 21589 (Saudi Arabia); Hassan, I.A., E-mail: ihassan_eg@yahoo.com [Air Pollution Laboratory (APL), Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, P. O. Box 80216, Jeddah 21589 (Saudi Arabia); Department of Botany, Faculty of Science, Alexandria University, 21526 El Shatby, Alexandria (Egypt)

    2014-11-01

    Egyptian pea cultivars (Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top chambers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009–2013) at a rural site in northern Egypt. Net photosynthetic rates (P{sub N}), stomatal conductance (g{sub s}), intercellular CO{sub 2} (C{sub i}) and chlorophyll fluorescence were measured. Ozone (O{sub 3}) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation. P{sub N} of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cultivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O{sub 3}. The maximum impairment in P{sub N} was recorded in the cultivar Victory (46%) in 2013 when the highest O{sub 3} levels were recorded (90 nL L{sup −1}). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between P{sub N} and C{sub i}, indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The P{sub N} vs. Ci curves were fitted to a non-rectangular hyperbolic model. The actual quantum yield (Φ{sub PSII}) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively. - Highlights: • Ozone (O{sub 3}) concentrations recorded were within the ranges of phytotoxicity. • O{sub 3} has a clear influence on the physiological

  5. The use of ambient air quality modeling to estimate individual and population exposure for human health research: a case study of ozone in the Northern Georgia Region of the United States.

    Bell, Michelle L

    2006-07-01

    Ambient monitors are commonly used to estimate exposure for epidemiological studies, and air quality modeling is infrequently applied. However air quality modeling systems have the potential to alleviate some, although not all, of the limitations of monitoring networks. To investigate this application, exposure estimates were generated for a case study high ozone episode in the Northern Georgia Region of the United States based on measurements and concentration estimates from an air quality modeling system. Hourly estimates for 2268 4-km by 4-km gridcells were generated in a domain that includes only eight ozone monitors. Individual and population-based ozone exposures were estimated using multiple approaches, including area-weighted average of modeled estimates, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. Results based on concentration fields from the air quality modeling system revealed spatial heterogeneity that was obscured by approaches based on the monitoring network. With some techniques, such as spatial interpolation, monitoring data alone was insufficient to estimate exposure for certain areas, especially for rural populations. For locations far from ozone monitors, the estimates from the nearest monitor approach tended to overestimate exposure, compared to modeled estimates. Counties in which one or more monitors were present had statistically higher population density and modeled ozone estimates than did counties without monitors (p-value <0.05). This work demonstrates the use of air quality modeling to generate higher spatial and temporal resolution exposure estimates, and compares the advantages of this approach to traditional methods that use monitoring data alone. The air quality modeling method faces its own limitations, such as the need to thoroughly evaluate concentration estimates and the use of ambient levels rather than personal exposure. PMID:16516968

  6. Fine root dynamics of mature European beech (Fagus sylvatica L.) as influenced by elevated ozone concentrations

    Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate. - Doubling of ozone concentrations in mature European beech affected the seasonal timing of fine root turnover rather than the turnover rate.

  7. Impacts of different plant functional types on ambient ozone predictions in the Seoul Metropolitan Areas (SMA, Korea

    H.-K. Kim

    2013-09-01

    isoprene and O3 prediction results, we explored the PFT area-loss artifact that occurs due to geographical disparity between the PFT and leaf area index distributions, and can cause increased bias in CMAQ O3. Thus, the PFT-loss artifact must be a source of limitation in the MEGAN biogenic emission modeling and the CTM O3 simulation results. Time changes of CMAQ O3 distributions with the different PFT scenarios suggest that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 10 ppb. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of representative PFT distributions becomes more critical for O3 air quality modeling (or forecasting in support of air quality decision-making and human health studies.

  8. Impacts of different plant functional types on ambient ozone predictions in the Seoul Metropolitan Areas (SMAs), Korea

    Kim, H.-K.; Woo, J.-H.; Park, R. S.; Song, C. H.; Kim, J.-H.; Ban, S.-J.; Park, J.-H.

    2014-07-01

    trees (BTs) are the most significant contributor, followed by needleleaf trees (NTs), shrub (SB), and herbaceous plants (HBs) to the total BVOCs. In addition, isoprene from BTs and terpene from NTs were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. A geographically weighted regression analysis with locally compensated ridge (LCR-GWR) with the different PFT data (δO3 vs. δPFTs) suggests that addition of BT, SB, and NT areas can contribute to O3 increase, whereas addition of an HB area contributes to O3 decrease in the domain. Assessment results of the simulated spatial and temporal changes of O3 distributions with the different PFT scenarios reveal that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 13 ppb. The simulated maximum 1 h O3 inter-deviations between different PFT scenarios have an asymmetric diurnal distribution pattern (low in the early morning, rising during the day, peaking at 05:00 p.m., and decreasing during the night) in the study domain. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of different PFT distribution data requires much caution when modeling (or forecasting) O3 air quality in complicated urban atmospheric conditions in terms of whether uncertainties in O3 prediction results are expected to be mild or severe.

  9. Impacts of different plant functional types on ambient ozone predictions in the Seoul Metropolitan Areas (SMA), Korea

    Kim, H.-K.; Woo, J.-H.; Park, R. S.; Song, C. H.; Kim, J.-H.; Ban, S.-J.; Park, J.-H.

    2013-09-01

    3 prediction results, we explored the PFT area-loss artifact that occurs due to geographical disparity between the PFT and leaf area index distributions, and can cause increased bias in CMAQ O3. Thus, the PFT-loss artifact must be a source of limitation in the MEGAN biogenic emission modeling and the CTM O3 simulation results. Time changes of CMAQ O3 distributions with the different PFT scenarios suggest that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 10 ppb. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of representative PFT distributions becomes more critical for O3 air quality modeling (or forecasting) in support of air quality decision-making and human health studies.

  10. Atmospheric nitrogen dioxide at ambient levels stimulates growth and development of horticultural plants

    Adam, S.E.H.; Shigeto, J. [Hiroshima Univ., Hiroshima (Japan). Dept. of Mathematical and Life Sciences; Sakamoto, A.; Takahashi, M.; Morikawa, H. [Hiroshima Univ., Hiroshima (Japan). Dept. of Mathematical and Life Sciences, Core Research for Evolutional Science and Technology

    2008-02-15

    Studies have demonstrated that ambient levels of atmospheric nitrogen dioxide (NO{sub 2}) can cause Nicotiana plumbaginifolia to double its biomass as well as its cell contents. This paper examined the influence of NO{sub 2} on lettuce, sunflower, cucumber, and pumpkin plants. Plants were grown in environments supplemented with stable isotope-labelled NO{sub 2} for approximately 6 weeks and irrigated with nitrates. Measured growth parameters included leaf number, internode number, stem length, number of flower buds, and root length. Results of the study demonstrated that the addition of NO{sub 2} doubled the aboveground and belowground biomass of sunflowers, while only the aboveground biomass of pumpkin, cucumbers, and lettuces was doubled. Levels of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also doubled in the lettuce samples. A mass spectrometry analysis showed that only a small percentage of total plant N was derived from NO{sub 2}. It was concluded that exogenous NO{sub 2} additions function as a signal rather than as a significant nutrient source in horticultural plants. 22 refs., 2 tabs., 1 fig.

  11. Atmospheric nitrogen dioxide at ambient levels stimulates growth and development of horticultural plants

    Studies have demonstrated that ambient levels of atmospheric nitrogen dioxide (NO2) can cause Nicotiana plumbaginifolia to double its biomass as well as its cell contents. This paper examined the influence of NO2 on lettuce, sunflower, cucumber, and pumpkin plants. Plants were grown in environments supplemented with stable isotope-labelled NO2 for approximately 6 weeks and irrigated with nitrates. Measured growth parameters included leaf number, internode number, stem length, number of flower buds, and root length. Results of the study demonstrated that the addition of NO2 doubled the aboveground and belowground biomass of sunflowers, while only the aboveground biomass of pumpkin, cucumbers, and lettuces was doubled. Levels of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also doubled in the lettuce samples. A mass spectrometry analysis showed that only a small percentage of total plant N was derived from NO2. It was concluded that exogenous NO2 additions function as a signal rather than as a significant nutrient source in horticultural plants. 22 refs., 2 tabs., 1 fig

  12. Effects of growth retardants and fumigations with ozone and sulfur dioxide on growth and flowering of Euphorbia pulcherrima Willd

    Cathey, H.M.; Heggestad, H.E.

    1973-01-01

    Eight cultivars of poinsettia, Euphorbia pulcherrima Willd., were evaluated for sensitivity to ..cap alpha..-cyclopropyl-..cap alpha.. (4-methoxyphenyl)-5-pyrimidine methanol (ancymidol) and protection from ozone and sulfur dioxide injury afforded by applications of ancymidol and (2-chloroethyl) trimethyl ammonium chloride (chlormequat). Foliar sprays of ancymidol were at least 80 to 500 times and the soil drench 1000 times more active than chlormequat in retarding stem elongation. The diam of the bracts was reduced, but branching increased more on plants treated with ancymidol than on untreated plants. The cv. Annette Hegg (AH) was more sensitive to ozone fumigations than was Eckespoint C-1' (C-1). Sulfur dioxide also caused more injury to AH than to C-1. Ancymidol and chlormequat reduced visible injury induced by ozone and sulfur dioxide.

  13. Use of AIRS, OMI, MLS, and TES Data in Assessing Forest Ecosystem Exposure to Ozone

    Spruce, Joseph P.

    2007-01-01

    Ground-level ozone at high levels poses health threats to exposed flora and fauna, including negative impacts to human health. While concern is common regarding depletion of ozone in the stratosphere, portions of the urban and rural United States periodically have high ambient levels of tropospheric ozone on the ground. Ozone pollution can cause a variety of impacts to susceptible vegetation (e.g., Ponderosa and Jeffrey pine species in the southwestern United States), such as stunted growth, alteration of growth form, needle or leaf chlorosis, and impaired ability to withstand drought-induced water stress. In addition, Southern Californian forests with high ozone exposures have been recently subject to multiyear droughts that have led to extensive forest overstory mortality from insect outbreaks and increased incidence of wildfires. Residual forests in these impacted areas may be more vulnerable to high ozone exposures and to other forest threats than ever before. NASA sensors collect a wealth of atmospheric data that have been used recently for mapping and monitoring regional tropospheric ozone levels. AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), MLS (Microwave Limb Sounder), and TES (Tropospheric Emission Spectrometer) data could be used to assess forest ecosystem exposure to ozone. Such NASA data hold promise for providing better or at least complementary synoptic information on ground-level ozone levels that Federal agency partners can use to assess forest health trends and to mitigate the threats as needed in compliance with Federal laws and mandates. NASA data products on ozone concentrations may be able to aid applications of DSTs (decision support tools) adopted by the USDA FS (U.S. Department of Agriculture Forest Service) and by the NPS (National Park Service), such as the Ozone Calculator, in which ground ozone estimates are employed to assess ozone impacts to forested vegetation.

  14. Effects of long-term open-field ozone exposure on leaf phenolics of European silver birch (Betula pendula Roth).

    Saleem, A; Loponen, J; Pihlaja, K; Oksanen, E

    2001-05-01

    The response of phenolic compounds as a result of long-term low open-field ozone exposure was studied in ozone-sensitive and ozone-tolerant clones of European silver birch (Betula pendula Roth). The saplings were exposed to 1.5-1.6 times the ambient (elevated) ozone and ambient air (as control) over three growing seasons from May 1996 until August 1998. Quantification by modified Folin-Ciocalteau assay showed a 16.2% increase in total phenolics in elevated ozone plants as compared to that in controls and a corresponding 9.9% increase of 10 phenolic compounds quantified by HPLC. Five nonflavonoids and five flavonoids showed 8.4% and 11.4% increases, respectively. The phenolic results indicated slightly higher ozone sensitivity of clone 5 as compared to clone 2. The most ozone-responsive phenolic compounds in clone 2 and clone 5 were (+)-catechin (CT), chlorogenic acid (CGA), 5-p-coumaroylquinic acid (5CQA), 3-p-coumaroylquinic acid (3CQA), myricetin galactopyranoside (MG), quercetin-3-O-glucuronopyranoside (QGR), and quercetin-3-O-arabinofuranoside (QA). Increased phenolic content in ozone-exposed plants was related to impaired growth and accelerated leaf senescence, indicated by enhanced autumn leaf yellowing and lower chlorophyll and Mg content. The change in carbon allocation towards defensive phenolics at the expense of growth was greater in the ozone-sensitive clone as compared to tolerant clone. PMID:11471939

  15. Impacts of Ozone-vegetation Interactions and Biogeochemical Feedbacks on Atmospheric Composition and Air Quality Under Climate Change

    Sadeke, M.; Tai, A. P. K.; Lombardozzi, D.; Val Martin, M.

    2015-12-01

    Surface ozone pollution is one of the major environmental concerns due to its damaging effects on human and vegetation. One of the largest uncertainties of future surface ozone prediction comes from its interaction with vegetation under a changing climate. Ozone can be modulated by vegetation through, e.g., biogenic emissions, dry deposition and transpiration. These processes are in turn affected by chronic exposure to ozone via lowered photosynthesis rate and stomatal conductance. Both ozone and vegetation growth are expected to be altered by climate change. To better understand these climate-ozone-vegetation interactions and possible feedbacks on ozone itself via vegetation, we implement an online ozone-vegetation scheme [Lombardozzi et al., 2015] into the Community Earth System Model (CESM) with active atmospheric chemistry, climate and land surface components. Previous overestimation of surface ozone in eastern US, Canada and Europe is shown to be reduced by >8 ppb, reflecting improved model-observation comparison. Simulated surface ozone is lower by 3.7 ppb on average globally. Such reductions (and improvements) in simulated ozone are caused mainly by lower isoprene emission arising from reduced leaf area index in response to chronic ozone exposure. Effects via transpiration are also potentially significant but require better characterization. Such findings suggest that ozone-vegetation interaction may substantially alter future ozone simulations, especially under changing climate and ambient CO2 levels, which would further modulate ozone-vegetation interactions. Inclusion of such interactions in Earth system models is thus necessary to give more realistic estimation and prediction of surface ozone. This is crucial for better policy formulation regarding air quality, land use and climate change mitigation. Reference list: Lombardozzi, D., et al. "The Influence of Chronic Ozone Exposure on Global Carbon and Water Cycles." Journal of Climate 28.1 (2015): 292-305.

  16. Increased Growth Factors Play a Role in Wound Healing Promoted by Noninvasive Oxygen-Ozone Therapy in Diabetic Patients with Foot Ulcers

    Jing Zhang

    2014-01-01

    Full Text Available Management of diabetic foot ulcers (DFUs is a great challenge for clinicians. Although the oxygen-ozone treatment improves the diabetic outcome, there are few clinical trials to verify the efficacy and illuminate the underlying mechanisms of oxygen-ozone treatment on DFUs. In the present study, a total of 50 type 2 diabetic patients complicated with DFUs, Wagner stage 2~4, were randomized into control group treated by standard therapy only and ozone group treated by standard therapy plus oxygen-ozone treatment. The therapeutic effects were graded into 4 levels from grade 0 (no change to grade 3 (wound healing. The wound sizes were measured at baseline and day 20, respectively. Tissue biopsies were performed at baseline and day 11. The expressions of vascular endothelial growth factor (VEGF, transforming growth factor-β (TGF-β, and platelet-derived growth factor (PDGF proteins in the pathologic specimens were determined by immunohistochemical examinations. The effective rate of ozone group was significantly higher than that of control group (92% versus 64%, P<0.05. The wound size reduction was significantly more in ozone group than in control group (P<0.001. After treatment, the expressions of VEGF, TGF-β, and PDGF proteins at day 11 were significantly higher in ozone group than in control group. Ozone therapy promotes the wound healing of DFUs via potential induction of VEGF, TGF-β, and PDGF at early stage of the treatment. (Clinical trial registry number is ChiCTR-TRC-14004415.

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

    Atkinson, Richard W.; Butland, Barbara K.; DIMITROULOPOULOU Chrysanthi; Heal, Mathew R.; Stedman, John R; Carslaw, Nicola; Jarvis, Deborah L; Heaviside, Clare; Vardoulakis, Sotiris; Walton, Heather; Anderson, H Ross

    2016-01-01

    Objectives 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. Methods Cohort studies published in peer-reviewed journals indexed in EMBASE an...

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

    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

    2016-01-01

    Objectives: 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. Methods: Cohort studies published in peer-reviewed journals indexed in EMBASE ...

  19. Growth of lithium silicate crystals inside porous silicon film and their exploitation for ozone detection

    Silicon dioxide was formed by oxidizing porous silicon film and annealed, in a next step, at 920 deg. C with lithium nitrate embedded in its structure. These operations have produced the two lithium silicates, Li2Si2O5 and Li2SiO3, as it has been confirmed by the X-ray diffraction measurements. At relative high temperature (230 deg. C), the experimental ionic conductivity of this achieved sample has doubled in presence of ozone flow. A comparison with other samples, prepared with varieties of metallic nitrates and by following the same experimental procedures as for the former one, has proved that the sample prepared with zirconium was also good for ozone detection

  20. Growth of lithium silicate crystals inside porous silicon film and their exploitation for ozone detection

    Ben Saad, K. [Centre de Recherches et des Technologies de l' Energie, Laboratoire de Nanomateriaux et des Systemes pour l' energie, BP 95, 2050 Hammam-Lif (Tunisia)], E-mail: BenSaadKhaled2005@yahoo.fr; Hamzaoui, H. [Centre de Recherches et des Technologies de l' Energie, Laboratoire des procedes chimique, BP 95, 2050 Hammam-Lif (Tunisia); Labidi, A. [Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, BP 51, La Marsa 2070, Tunis (Tunisia); Bessais, B. [Centre de Recherches et des Technologies de l' Energie, Laboratoire de Nanomateriaux et des Systemes pour l' energie, BP 95, 2050 Hammam-Lif (Tunisia)

    2008-04-30

    Silicon dioxide was formed by oxidizing porous silicon film and annealed, in a next step, at 920 deg. C with lithium nitrate embedded in its structure. These operations have produced the two lithium silicates, Li{sub 2}Si{sub 2}O{sub 5} and Li{sub 2}SiO{sub 3}, as it has been confirmed by the X-ray diffraction measurements. At relative high temperature (230 deg. C), the experimental ionic conductivity of this achieved sample has doubled in presence of ozone flow. A comparison with other samples, prepared with varieties of metallic nitrates and by following the same experimental procedures as for the former one, has proved that the sample prepared with zirconium was also good for ozone detection.

  1. Measurement of Ozone Production Sensor

    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.

  2. Chronic drought stress reduced but not protected Shantung maple (Acer truncatum Bunge) from adverse effects of ozone (O3) on growth and physiology in the suburb of Beijing, China

    A two-year experiment exposing Acer truncatum Bunge seedlings to elevated ozone (O3) concentrations above ambient air (AO) and drought stress (DS) was carried out using open-top chambers (OTCs) in a suburb of Beijing in north China in 2012–2013. The results suggested that AO and DS had both significantly reduced leaf mass area (LMA), stomatal conductance (Gs), light saturated photosynthetic rate (Asat) as well as above and below ground biomass at the end of the experiment. It appeared that while drought stress mitigated the expression of foliar injury, LMA, leaf photosynthetic pigments, height growth and basal diameter, due to limited carbon fixation, the O3 – induced reductions in Asat, Gs and total biomass were enhanced 23.7%. 15.5% and 8.1% respectively. These data suggest that when the whole plant was considered that drought under the conditions of this experiment did not protect the Shantung maple seedlings from the effects of O3. - Highlights: • The response of Acer truncatum Bunge to drought and ozone was investigated. • Drought could mitigate the foliage injury and leaf photosynthetic pigments. • The O3-induced reductions in Asat, Gs and total biomass were enhanced by drought. - Drought didn't protect Shantung maple from O3 effects but rather cause more reductions in biomass

  3. The role of Si interstitials in the migration and growth of Ge nanocrystallites under thermal annealing in an oxidizing ambient

    Chen, Kuan-Hung; Wang, Ching-Chi; George, Tom; Li, Pei-Wen

    2014-01-01

    We report a unique growth and migration behavior of Ge nanocrystallites mediated by the presence of Si interstitials under thermal annealing at 900°C within an H2O ambient. The Ge nanocrystallites were previously generated by the selective oxidation of SiGe nanopillars and appeared to be very sensitive to the presence of Si interstitials that come either from adjacent Si3N4 layers or from within the oxidized nanopillars. A cooperative mechanism is proposed, wherein the Si interstitials aid in...

  4. Ambient-condition growth of high-pressure phase centrosymmetric crystalline KDP microstructures for optical second harmonic generation.

    Ren, Yan; Zhao, Xian; Hagley, Edward W; Deng, Lu

    2016-08-01

    Noncentrosymmetric potassium dihydrogen phosphate (KH2PO4 or KDP) in the tetragonal crystal phase is arguably the most extensively studied nonlinear optical crystal in history. It has prolific applications ranging from simple laser pointers to laser inertial confinement fusion systems. Recently, type IV high-pressure KDP crystal sheets with a monoclinic crystal phase having centrosymmetric properties have been observed. However, it was found that this new crystal phase is highly unstable under ambient conditions. We report ambient-condition growth of one-dimensional, self-assembled, single-crystalline KDP hexagonal hollow/solid-core microstructures that have a molecular structure and symmetry identical to the type IV KDP monoclinic crystal that was previously found to exist only at extremely high pressures (>1.6 GPa). Furthermore, we report highly efficient bulk optical second harmonic generation (SHG) from these ambient condition-grown single-crystalline microstructures, even though they have a highly centrosymmetric crystal phase. However, fundamental physics dictates that a bulk optical medium with a significant second-order nonlinear susceptibility supporting SHG must have noncentrosymmetric properties. Laue diffraction analysis reveals a weak symmetry-breaking twin-crystal lattice that, in conjunction with tight confinement of the light field by the tubular structure, is attributed to the significant SHG even with sample volumes <0.001 mm(3). A robust polarization-preserving effect is also observed, raising the possibility of advanced optical technological applications. PMID:27574703

  5. The Importance of Ambient Temperature to Growth and the Induction of Flowering.

    McClung, C R; Lou, Ping; Hermand, Victor; Kim, Jin A

    2016-01-01

    Plant development is exquisitely sensitive to the environment. Light quantity, quality, and duration (photoperiod) have profound effects on vegetative morphology and flowering time. Recent studies have demonstrated that ambient temperature is a similarly potent stimulus influencing morphology and flowering. In Arabidopsis, ambient temperatures that are high, but not so high as to induce a heat stress response, confer morphological changes that resemble the shade avoidance syndrome. Similarly, these high but not stressful temperatures can accelerate flowering under short day conditions as effectively as exposure to long days. Photoperiodic flowering entails a series of external coincidences, in which environmental cycles of light and dark must coincide with an internal cycle in gene expression established by the endogenous circadian clock. It is evident that a similar model of external coincidence applies to the effects of elevated ambient temperature on both vegetative morphology and the vegetative to reproductive transition. Further study is imperative, because global warming is predicted to have major effects on the performance and distribution of wild species and strong adverse effects on crop yields. It is critical to understand temperature perception and response at a mechanistic level and to integrate this knowledge with our understanding of other environmental responses, including biotic and abiotic stresses, in order to improve crop production sufficiently to sustainably feed an expanding world population. PMID:27602044

  6. Ambient ozone effects on gas exchange and total non-structural carbohydrate levels in cutleaf coneflower (Rudbeckia laciniata L.) growing in Great Smoky Mountains National Park

    Ozone-sensitive and -tolerant individuals of the perennial herbaceous cutleaf coneflower (Rudbeckia laciniata L.) were compared for their gas exchange characteristics and total non-structural carbohydrates in the Great Smoky Mountains National Park USA. Net photosynthesis decreased with increased f...

  7. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    S. Chatani

    2014-04-01

    Full Text Available A regional air quality simulation framework including the Weather Research and Forecasting modelling system (WRF, the Community Multi-scale Air Quality modeling system (CMAQ, and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitorings, ozone zondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2, nitrogen oxides (NOx, and volatile organic compound (VOC emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around north eastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

  8. Combination of U.V.-B and ozone reduces pollen tube growth more than either stress alone

    The rate of in vitro Nicotiana tabacum L. “Bel-W3” pollen tube growth was reduced 62 and 44%, respectively, when pollen tubes were exposed to 120 ppb ozone (O3) for 3 hr or 300 μW/cm2 ultraviolet-B (u.v.-B) radiation for 30 min. Petunia hybrida Vilm. “White Cascade” pollen tube growth was reduced 34 and 59%, respectively, upon exposure to O3 or u.v.-B at the above doses. The combination of u.v.-B at 300 μW/cm2 for 30 min, followed by O3 at 120 ppb for 3 hr, reduced pollen tube growth by 79% for “Bel-W3” and 75% for “White Cascade”. The effect appeared to be additive, implying that different target areas may be affected by the two stressors. In the Northeast, plants are exposed to both u.v.-B and O3 during the normal growing season. This may result in an unexpectedly higher stress on the reproductive system than had been previously suspected based on these two stressors acting individually. (author)

  9. Hyaluronan Mediates Ozone-induced Airway Hyperresponsiveness in Mice*

    Garantziotis, Stavros; Li, Zhuowei; Potts, Erin N.; Kimata, Koji; Zhuo, Lisheng; Morgan, Daniel L.; Savani, Rashmin C.; Noble, Paul W.; Foster, W. Michael; Schwartz, David A; John W Hollingsworth

    2009-01-01

    Ozone is a common urban environmental air pollutant and significantly contributes to hospitalizations for respiratory illness. The mechanisms, which regulate ozone-induced bronchoconstriction, remain poorly understood. Hyaluronan was recently shown to play a central role in the response to noninfectious lung injury. Therefore, we hypothesized that hyaluronan contributes to airway hyperreactivity (AHR) after exposure to ambient ozone. Using an established model of ozone...

  10. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... and regulations: Ozone. Determination of Attainment. Effective March 12, 2010 EPA has determined the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air...

  11. Enhanced attached growth of microalgae Scenedesmus. LX1 through ambient bacterial pre-coating of cotton fiber carriers.

    Zhuang, Lin-Lan; Azimi, Yaldah; Yu, Dawei; Wang, Wen-Long; Wu, Yin-Hu; Dao, Guo-Hua; Hu, Hong-Ying

    2016-10-01

    The role of bacteria/extracellular polymeric substances (EPS) coated carriers on attached microalgae growth in suspended-solid phase photobioreactor (sspBR) was assessed in this study. The results showed that pre-coating cotton with ambient bacteria and their EPS improved the attached microalgal growth by as much as 230% in terms of attached microalgae density. Additionally, the single cell dry weight, chemical composition and oxygen evolving activity of attached microalgae were significantly affected by the presence of bacteria/EPS coating on the cotton carriers. The protein content of microalgae cells cultivated in the ssPBRs with carriers coated by bacteria and sterilized bacteria were on average 26% and 15% more than uncoated carriers, respectively. Through absorbing and immobilizing nutrients from the bulk medium, the bacteria/EPS coating provided the attached microalgae with nitrogen/phosphorus for protein synthesis, especially during the late stages of batch cultivation. PMID:27416514

  12. Final report, on-going key comparison BIPM.QM-K1: ozone at ambient level, comparison with DMDM, July 2015

    Viallon, J.; Moussay, P.; Wielgosz, R.; Bebic, J.; Norris, J. E.; Guenther, F.

    2016-01-01

    As part of the on-going key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the Directorate of Measures and Precious Metals (DMDM) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM), via a transfer standard maintained by the National Institute of Standards and Technology (NIST). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  13. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    Chatani, S.; Amann, M.; Goel, A.; Hao, J.; Klimont, Z.; Kumar, A.; Mishra, A.; Sharma, S.; Wang, S. X.; Wang, Y. X.; Zhao, B.

    2014-09-01

    A regional air quality simulation framework including the Weather Research and Forecasting modeling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitoring, ozonesondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compound (VOC) emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU) pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around northeastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

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

    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.

  15. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    S. Chatani; M. Amann; Goel, A.; J. Hao; Z. Klimont; Kumar, A.; Mishra, A.; S Sharma; Wang, S. X.; Wang, Y. X.; B. Zhao

    2014-01-01

    A regional air quality simulation framework including the Weather Research and Forecasting modelling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitorings, ozone zondes, and satellites obt...

  16. Corona Discharge Influences Ozone Concentrations Near Rats

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  17. Growth of YBa2(Cu, Co)4O8 single crystals under ambient pressure and their superconducting properties

    We report the growth of superconducting YBa2(Cu, Co)4O8 single crystals using KOH flux under ambient pressure and their superconducting properties. The average size of the YBa2(Cu, Co)4O8 single crystals is 0.3 x 0.3 x 0.2 mm3. The superconducting transition temperature (Tc) of the parent material is found to be 81 K, indicating a stoichiometric oxide superconductor. The Tc and the c-axis length of YBa2(Cu, Co)4O8 single crystals decrease systematically with increasing the Co-doping content. A comparison of the magnetic irreversibility with the flux-creep theory from the viewpoint of homogeneity/inhomogeneity is made. (author)

  18. Multi-morphological growth of nano-structured In2Se3 by ambient pressure triethylene glycol based solution syntheses

    In2Se3 nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized by a new, facile, ambient pressure triethylene glycol based solution chemical route using indium(III) chloride and selenium powder as precursors. The growing morphology, crystallization, chemical stoichiometry and light absorption property of the In2Se3 products synthesized were characterized by TEM, HRTEM, FESEM, XRD, EDX and UV–vis–NIR measurements. Multi-morphological growth of the nano-structured In2Se3 in triethylene glycol based solution syntheses with changed assisting agents and reaction styles was demonstrated. - Highlights: • Multimorphological growth of In2Se3 was demonstrated based on solution chemistry. • A new, facile, low cost and fast air pressure TEG based solution process was used. • Nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized. • Morphology, crystallization, stoichiometry and light absorption was characterized. • Solution growth of β-In2Se3 nanosheets was firstly reported by this submission

  19. Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours

    A. Laaksonen

    2004-11-01

    Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulfur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

  20. Impact of Experimentally Elevated Ozone on Seed Germination and Growth of Russian Pine (Pinus sylvestris) and Spruce (Picea spp.) Provenances

    Prozherina, Nadezda; Nakvasina, Elena; Oksanen, Elina

    2009-01-01

    The impact of elevated ozone concentrations on early ontogenetic stages of pine (Pinus sylvestris) and spruce (Picea abies, Picea obovata, P. abies X P. obovata) seedlings originating from different provenances in Russia were studied in the open-field ozone fumigation system located in Kuopio, Finla

  1. Ambient levels and temporal trends of VOCs, including carbonyl compounds, and ozone at Cabañeros National Park border, Spain

    Villanueva, Florentina; Tapia, Araceli; Notario, Alberto; Albaladejo, José; Martínez, Ernesto

    2014-03-01

    Concentration levels of 15 carbonyls, 17 VOCs and ozone were studied at Cabañeros National Park border, Spain, in an area mainly constituted by holm oaks (Quercus ilex) and cork oaks (Quercus suber), along with scrubland formations such as rock-rose and heather. The compounds were collected by means of diffusive samplers from August-November 2010 and February-August 2011. Carbonyl compounds, VOCs and O3 were analysed by HPLC with diode array UV-Vis detector, GC-FID and by UV-visible spectrophotometry, respectively. The most abundant carbonyls were hexanal, acetone-acrolein, formaldehyde and acetaldehyde. Seasonal variation was apparent with maximum values observed in summer months. Total carbonyl concentrations ranged from 2.8 to 19.7 μg m-3. Most VOCs studied (using chemically desorbable cartridges) were either not detected or were below their detection limits, however, a parallel sampling using thermally desorbable cartridges, from May 22 to June 19, revealed the presence of much more VOCs, identified using GC-MS. O3 concentration ranged from 27.2 to 90.5 μg m-3, reaching the maximum monthly mean concentration in March (84.4 μg m-3). The analysis of back trajectories indicates the transport of polluted air masses from remote areas, mainly from the Mediterranean basin that should contribute to the high levels of ozone observed.

  2. An exploratory analysis of the relationship between ambient ozone and particulate matter concentrations during early pregnancy and selected birth defects in Texas

    We performed an exploratory analysis of ozone (O3) and fine particulate matter (PM2.5) concentrations during early pregnancy and multiple types of birth defects. Data on births were obtained from the Texas Birth Defects Registry (TBDR) and the National Birth Defects Prevention Study (NBDPS) in Texas. Air pollution concentrations were previously determined by combining modeled air pollution concentrations with air monitoring data. The analysis generated hypotheses for future, confirmatory studies; although many of the observed associations were null. The hypotheses are provided by an observed association between O3 and craniosynostosis and inverse associations between PM2.5 and septal and obstructive heart defects in the TBDR. Associations with PM2.5 for septal heart defects and ventricular outflow tract obstructions were null using the NBDPS. Both the TBDR and the NBPDS had inverse associations between O3 and septal heart defects. Further research to confirm the observed associations is warranted. - Highlights: • Air pollution concentrations combined modeled air data and air monitoring data. • No associations were observed between the majority of birth defects and PM2.5 and O3. • Estimated associations between PM2.5 and certain heart defects varied by dataset. • Results were suggestive of an inverse association between O3 and septal heart defects. • Higher O3 concentrations may be associated with increased odds of craniosynostosis. - Although most observed associations between ozone and fine particulate matter concentrations and birth defects were null, some were present and warrant further consideration

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

    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

  4. A review of the literature on the effects of ambient air pollution on fetal growth

    A systematic review of the literature on the effects of air pollution on low birth weight (LBW) and its determinants, preterm delivery (PTD) and intrauterine growth restriction (IUGR), was conducted. Twelve epidemiologic investigations that addressed the impact of air pollution on four pregnancy outcomes were identified. Results were analyzed separately for each perinatal outcome because of differences in pathogenic mechanisms. Effects of air pollution were apparent on PTD and IUGR, but not on LBW. Most of the associations reported were rather small. The estimation of summary effects was not meaningful because of the heterogeneity of the effect estimates arising from differences in the measurements of outcome, exposure, and confounders and the small number of studies per outcome (four studies for PTD and six for IUGR). Current scientific knowledge on the impact of air pollution on fetal growth is still limited; thus, several issues should be examined further

  5. Elevated atmospheric carbon dioxide and ozone concentrations alter LAI through changes in phenology and leaf growth

    Leaves are critical for harvesting light energy, taking up carbon dioxide (CO2) and transpiring water for cooling. Changes in leaf growth, expansion or development can integrate across the plant canopy and growing season to significantly impact productivity, yield and plant-atmosphere fluxes. Althou...

  6. 环境空气中臭氧API评价探讨%Study on Air Ozone API Evaluation

    徐建平

    2012-01-01

    Air ozone API evaluation is considered that area of influence on ozone concentration exceed ambient air quality, ozone API correction on hours on ozone concentration exceed ambient air quality and Ozone average concentration exceed ambient air quality.%环境空气中臭氧API评价应考虑臭氧超标影响范围、臭氧超标小时数和超标平均浓度对臭氧API修正.

  7. Modeling of Stomatal Conductance for Estimating Ozone Uptake of Fagus crenata Under Experimentally Enhanced Free-air Ozone Exposure

    Hoshika, Yasutomo; Watanabe, Makoto; Inada, Naoki; KOIKE, Takayoshi

    2012-01-01

    We examined a performance of the multiplicative stomatal conductance model to estimate the stomatal ozone uptake for Fagus crenata. Parameterization of the model was carried out by in-situ measurements in a free-air ozone exposure experiment. The model performed fairly well under ambient conditions, with low ozone concentration. However, the model overestimated stomatal conductance under enhanced ozone condition due to ozone-induced stomatal closure. A revised model that included a parameter ...

  8. Effects of Ambient Humidity on Plant Growth Enhancement by Atmospheric Air Plasma Irradiation to Plant Seeds

    Sarinont, Thapanut; Amano, Takaaki; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Humidity is an important factor for plasma-bio applications because composition of species generated by atmospheric pressure plasmas significantly depends on the humidity. Here we have examined effects of humidity on the growth enhancement to study the mechanism. Experiments were carried out with a scalable DBD device. 10 seeds of Raphanus sativus L. were set for x = 5 mm and y = 3 mm below the electrodes. The humidity Hair was 10 - 90 %Rh. The ratio of length of plants with plasma irradiation to that of control increases from 1.2 for Hair = 10 %Rh to 2.5 for Hair = 50 %Rh. The ratio is 2.5 for Hair = 50-90 %Rh. This humidity dependence is similar to the humidity dependence of O2+-H2O,H3O*, NO2--H2Oand NO3--H2Odensities, whereas it is different from that of other species such as O3, NO, and so on. The similarity gives information on key species for the growth enhancement.

  9. Exposure-Relevant Ozone Chemistry in Occupied Spaces

    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. Effects of ozone on growth, net photosynthesis and yield of two African varieties of Vigna unguiculata.

    Tetteh, Rashied; Yamaguchi, Masahiro; Wada, Yoshiharu; Funada, Ryo; Izuta, Takeshi

    2015-01-01

    To assess the effects of O(3)on growth, net photosynthesis and yield of two African varieties of cowpea(Vigna unguiculata L.), Blackeye and Asontem were exposed as potted plants to air that was either filtered to remove O(3) (FA), non-filtered air (NF), non-filtered with added O3 of approximately 50 nL L(-1) (ppb) from 11:00 to 16:00 (NF + O(3)) for 88 days in open-top chambers. The mean O(3) concentration (11:00-16:00) during the exposure period had a range from 16 ppb in the FA treatment to 118 ppb in the NF + O(3) treatment. Net photosynthetic rate and leaf area per plant were significantly reduced by exposure to O(3), reducing the growth of both varieties. Exposure to O(3) significantly reduced the 100-seed weight and number of seeds per pod. As a result, cowpea yield was significantly reduced by long-term exposure to O(3), with no difference in sensitivity between the varieties. PMID:25463718

  11. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    S. Chatani; M. Amann; Goel, A.; J. Hao; Z. Klimont; Kumar, A.; Mishra, A.; S Sharma; Wang, S. X.; Wang, Y. X.; B. Zhao

    2014-01-01

    A regional air quality simulation framework including the Weather Research and Forecasting modeling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitoring, ozonesondes, and satellites obtained in 2010. The simul...

  12. In situ laser ablation plasma diagnostics in the film growth regime: Effects of ambient background gases

    The propagation of the laser-induced plasma formed by KrF irradiation of Y1Ba2Cu3O7 has been characterized in background pressures of oxygen and argon typically used for thin film growth. The ion current transmitted through the background gases was recorded along the normal to the irradiated pellet as a function of distance in order to measure the decreasing velocity and magnitude of the expanding plasma current due to collisional slowing and attenuation of the laser plume. The integrated ion charge delivered to a substrate at low pressures can be described by elastic scattering giving a general integral cross sections of σe[O2] = 3.2 x 10-16 cm2 and σe[Ar] = 2.7 x 10-16 cm2. At higher pressures, inelastic scattering leads to increased recombination and reactive conversion of ions indicated by increased fluorescence of all the species, which becomes dominated by fluorescence of YO and BaO. Spatially resolved fluorescence measurements indicate that the luminous boundary to the plasma follows a weak shock front which coincides with the ion flux propagation. The ion transmission is found to drop exponentially with distance and background pressure, in agreement with a simple scattering model which yields general scattering cross sections for ion-argon σi-Ar = 2.1 x 10-16 cm2 and ion-oxygen σi-O2 = 2.3 x 10-16 cm2 interactions in background pressures up to 300 mTorr. The general features of the plume deceleration are described in terms of a drag force model. 9 refs., 5 figs

  13. Use of the antiozonant ethylenediurea (EDU) in Italy: Verification of the effects of ambient ozone on crop plants and trees and investigation of EDU's mode of action

    Paoletti, Elena, E-mail: e.paoletti@ipp.cnr.i [IPP-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy); Contran, Nicla [Department of Biotechnology and Biology, University of Milano-Bicocca, Piazza della Scienza 1, Milan (Italy); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States); Ferrara, Anna M. [IPLA, Corso Casale 476, I-10128 Turin (Italy)

    2009-05-15

    Twenty-four experiments where EDU was used to protect plants from ozone (O{sub 3}) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O{sub 3}-caused visible injury and growth reductions in crop and forest species respectively. EDU was mainly applied as soil drench to crops and by stem injection or infusion into trees. Visible injury was delayed and reduced but not completely. In investigations on mode of action, EDU was quickly (<2 h) uptaken and translocated to the leaf apoplast where it persisted long (>8 days), as it cannot move via phloem. EDU did not enter cells, suggesting it does not directly affect cell metabolism. EDU delayed senescence, did not affect photosynthesis and foliar nitrogen content, and stimulated antioxidant responses to O{sub 3} exposure. Preliminary results suggest developing an effective soil application method for forest trees is warranted. - EDU was successful as a tool in determining ozone effects on vegetation in Italy, but while progress was made, its mode of action remains unresolved.

  14. Effect of Different Arbuscular Mycorrhizal Fungi on Growth and Physiology of Maize at Ambient and Low Temperature Regimes

    Xiaoying Chen

    2014-01-01

    Full Text Available The effect of four different arbuscular mycorrhizal fungi (AMF on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress.

  15. Ozone dose-response relationships for spring oilseed rape and broccoli

    De Bock, Maarten; Op de Beeck, Maarten; De Temmerman, Ludwig; Guisez, Yves; Ceulemans, Reinhart; Vandermeiren, Karine

    2011-03-01

    Tropospheric ozone is an important air pollutant with known detrimental effects for several crops. Ozone effects on seed yield, oil percentage, oil yield and 1000 seed weight were examined for spring oilseed rape ( Brassica napus cv. Ability). For broccoli ( Brassica oleracea L. cv. Italica cv. Monaco) the effects on fresh marketable weight and total dry weight were studied. Current ozone levels were compared with an increase of 20 and 40 ppb during 8 h per day, over the entire growing season. Oilseed rape seed yield was negatively correlated with ozone dose indices calculated from emergence until harvest. This resulted in an R2 of 0.24 and 0.26 ( p rape. The reduction of oilseed rape yield showed the highest correlation with the ozone uptake during the vegetative growth stage: when only the first 47 days after emergence were used to calculate POD 6, R2 values increased up to 0.476 or even 0.545 when the first 23 days were excluded. The highest ozone treatments, corresponding to the future ambient level by 2100 (IPCC, Meehl et al., 2007), led to a reduction of approximately 30% in oilseed rape seed yield in comparison to the current ozone concentrations. Oil percentage was also significantly reduced in response to ozone ( p < 0.001). As a consequence oil yield was even more severely affected by elevated ozone exposure compared to seed yield: critical levels for oil yield dropped to 3.2 ppm h and 3.9 mmol m -2. For broccoli the applied ozone doses had no effect on yield.

  16. Effects of ozone on growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat (Triticum aestivum L.).

    Akhtar, Nahid; Yamaguchi, Masahiro; Inada, Hidetoshi; Hoshino, Daiki; Kondo, Taisuke; Izuta, Takeshi

    2010-05-01

    To clarify the effects of O(3) on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O(3) at 60 and 100 nl l(-1) (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O(3). Although there was no significant effect of O(3) on stomatal diffusive conductance to H(2)O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O(3.) The sensitivity of growth, yield, yield components and leaf gas exchange rates to O(3) was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O(3) may detrimentally affect wheat production in Bangladesh. PMID:19962222

  17. Effects of elevated ozone on growth and yield of field-grown rice in Yangtze River Delta,China

    CHEN Zhan; WANG Xiaoke; FENG Zhaozhong; ZHENG Feixiang; DUAN Xiaonan; YANG Wenrui

    2008-01-01

    With rapid industrialization and urbanization in the Yangtze Delta,China,the tropospheric ozone concentration has increased to levels that induce orop yield loss.Rice,a widely grown crop in China,was investigated in field-established,open-top chambers.Four treatments were used:charcoal-filtered air (CF),non-charcoal-filtered air (NF),and charcoal-filtered air with two levels of additional ozone (O3-1 and O3-2).The AOT40s (accumulated hourly mean ozone concentration above 40 ppbv) were 0,0.91,23.24,and 39.28 ppmv.h for treatraent of CF,NF,O3-1,and O3-2,respectively.The rice height and biomass were reduced in the elevated ozone concentration.Less organic matter partitioning to roots under the elevated ozone significantly decreased rice root activity.The yield loss was 14.3% and 20.2% under O3-1 and O3-2 exposure,respectively.This was largely caused by a reduction in grain weight per panicle.

  18. Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

    In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac)2], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1 ± 0.01 nm/cycle within the wide ALD temperature window of 175–300 °C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure, refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnOx–Si interface. The resistivity of the SnOx films was calculated to be 0.3 Ω cm. Results of this work demonstrate the possibility of introducing Sn(acac)2 as tin precursor to deposit conducting ALD SnOx thin films on a silicon surface, with clean interface and no formation of undesired SiO2 or other interfacial reaction products, for transparent conducting oxide applications

  19. Ambient Air Pollution and Birth Weight in Full-Term Infants in Atlanta, 1994–2004

    Darrow, Lyndsey A.; Klein, Mitchel; Strickland, Matthew J; Mulholland, James A.; Tolbert, Paige E.

    2010-01-01

    Background An emerging body of evidence suggests that ambient levels of air pollution during pregnancy are associated with fetal growth. Objectives We examined relationships between birth weight and temporal variation in ambient levels of carbon monoxide, nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone, particulate matter ≤ 10 μm in diameter (PM10), ≤ 2.5 μm (PM2.5), 2.5 to 10 μm (PM2.5–10), and PM2.5 chemical component measurements for 406,627 full-term births occurring between 1994 and ...

  20. Plant Species Sensitivity Distributions for ozone exposure

    This study derived Species Sensitivity Distributions (SSD), representing a cumulative stressor-response distribution based on single-species sensitivity data, for ozone exposure on natural vegetation. SSDs were constructed for three species groups, i.e. trees, annual grassland and perennial grassland species, using species-specific exposure–response data. The SSDs were applied in two ways. First, critical levels were calculated for each species group and compared to current critical levels for ozone exposure. Second, spatially explicit estimates of the potentially affected fraction of plant species in Northwestern Europe were calculated, based on ambient ozone concentrations. We found that the SSD-based critical levels were lower than for the current critical levels for ozone exposure, with conventional critical levels for ozone relating to 8–20% affected plant species. Our study shows that the SSD concept can be successfully applied to both derive critical ozone levels and estimate the potentially affected species fraction of plant communities along specific ozone gradients. -- Highlights: ► Plant Species Sensitivity Distributions were derived for ozone exposure. ► Annual grassland species, as a species assemblage, tend to be most sensitive to ozone. ► Conventional critical levels for ozone relate to 8–20% affected plant species. ► The affected fraction of plant species for current ozone exposure in Northwestern Europe is estimated. -- Species Sensitivity Distributions offer opportunities in ozone risk assessment to both derive critical levels and estimate the affected fraction of a plant community

  1. Modeling the effect of temperature on ozone-related mortality

    Wilson, Ander; Rappold, Ana G.; Neas, Lucas M.; Reich, Brian J.

    2014-01-01

    Climate change is expected to alter the distribution of ambient ozone levels and temperatures which, in turn, may impact public health. Much research has focused on the effect of short-term ozone exposures on mortality and morbidity while controlling for temperature as a confounder, but less is known about the joint effects of ozone and temperature. The extent of the health effects of changing ozone levels and temperatures will depend on whether these effects are additive or synergistic. In t...

  2. Influence of Feeding Enzymatically Hydrolyzed Yeast Cell Wall on Growth Performance and Digestive Function of Feedlot Cattle during Periods of Elevated Ambient Temperature

    Salinas-Chavira, J.; Arzola, C.; González-Vizcarra, V.; Manríquez-Núñez, O. M.; Montaño-Gómez, M. F.; Navarrete-Reyes, J. D.; Raymundo, C.; Zinn, R. A.

    2015-01-01

    In experiment 1, eighty crossbred steers (239±15 kg) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h ...

  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

    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 O3 effects on leaf growth and visible injury is controversial. - Both biochemical and biophysical processes may regulate EDU action

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

    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...

  5. The effects of feed restriction and ambient temperature on growth and ascites mortality of broilers reared at high altitude.

    Ozkan, S; Takma, C; Yahav, S; Sögüt, B; Türkmut, L; Erturun, H; Cahaner, A

    2010-05-01

    The development of ascites was investigated in broilers at low versus high altitudes, cold versus normal ambient temperatures (AT), and 3 feeding regimens. One-day-old chicks obtained at sea level were reared at high altitude (highA; 1,720 m; n = 576) with 2 AT treatments, low AT from 3 wk onward at highA (highA/cold) and normal AT from 3 wk onward at highA (highA/norm), or at sea level (normal AT from 3 wk onward at low altitude, lowA/norm; n = 540). Under highA/cold, AT ranged between 16 to 17 degrees C in the fourth week, 17 to 19 degrees C in the fifth week, and 19 to 21 degrees C thereafter. Under highA/norm and lowA/norm, AT was 24 degrees C in the fourth week and ranged between 22 to 24 degrees C thereafter. Broilers in each condition were divided into 3 groups: feed restriction (FR) from 7 to 14 d, FR from 7 to 21 d, and ad libitum (AL). Ascites mortality and related parameters were recorded. Low mortality (0.4%) occurred under lowA/norm conditions. Under highA/norm, mortality was lower in females (8.6%) than in males (13.8%) and was not affected by the feeding regimen. The highA/cold treatment resulted in higher mortality but only in males; it was 44.2% among highA/cold AL-fed males and only about 26% under the FR regimens, suggesting that FR helped some males to better acclimatize to the highA/cold environment and avoid ascites. However, mortality was only 13.3% in AL-fed males at highA/norm and FR did not further reduce the incidence of ascites under these conditions. Thus, avoiding low AT in the poultry house by slight heating was more effective than FR in reducing ascites mortality at highA. Compared with FR from 7 to 14 d, FR from 7 to 21 d did not further reduce mortality and reduced growth. At 47 d, the majority of surviving broilers at highA had high levels of hematocrit and right ventricle:total ventricle weight ratio (>0.29), but they were healthy and reached approximately the same BW as their counterparts at low altitude. This finding may

  6. Ozone threat

    Ozone hole was first discovered in 1980. Thus 15 years even after the first warming, the world is no where near to the elimination of man made gases that threaten to destroy the ozone layer. Ozone depletion has become a matter of enormous threat which remains to be solved by the Scientists and intelligentia of the world. Ozone (O3) is a pungent poisonous gas. It forms a layer at a distance of about 15 miles above the earth's surface which helps shield living things from the sun shearing ultra violet light. If ozone is lost, more ultra violet light reaches the earth, which can lead to increasing rate of skin cancer, the death of micro organisms and the failure of crops and plants. It was in 1974 when it was discovered that Chlorofluorocarbons (CFCs) cold rise slowly to the upper atmosphere and destroy the earth's fragile ozone shield. Chlorofluorocarbons are commonly used as coolants (such as Freon) for home and automobile air conditioners and in the making of fast food containers. CFCs take about 100 years or more to reach he stratosphere to damage the ozone layers. In 1988, Scientists confirmed that upto 3% of the ozone layer over the more populated Northern Hemisphere has been destroyed. it is believed that for every 1% decrease in ozone, skin cancers are expected to rise 5 to 6 per cent due to the increase of ultraviolet light. Cases of cataracts and certain human immune system diseases are also expected to rise. (author)

  7. Einfluss von Ozon, CO2 und Trockenstress auf das Wachstum und die Pollenproduktion der Beifuß-Ambrosie (Ambrosia artemisiifolia)

    El Kelish, Amr; Winkler, J. Barbro; Lang, Hans; Holzinger, Andreas; Behrendt, Heidrun; Durner, Jörg; Kanter, Ulrike; Ernst, Dieter

    2014-01-01

    Climate change will affect the growth of plants and may also influence the production of pollen. The important factors influencing climate change are increased CO2 concentrations, drought and air pollution. Common ragweed pollen is known to be strongly allergenic, thereby affecting human health. In this study, common ragweed plants were grown over an entire vegetation period under conditions of twice the ambient level of CO2 (700 ppm) and ozone (80 ppm), respectively. Furthermore, the effect ...

  8. Ozone and cardiovascular injury

    Rainaldi Giuseppe

    2009-06-01

    and mortality 3. Most of the evidence comes from studies of ambient particles concentrations. However, in Europe and elsewhere, the air pollution profile has gradually changed toward a more pronounced photochemical component. Ozone is one of the most toxic components of the photochemical air pollution mixture. Indeed, the biological basis for these observations has not been elucidated. In the present review, the role of ozone as chemical molecule will be firstly considered. Secondly, pathogenetic mechanisms connecting the atmospheric ozone level and cardiovascular pathology will be examined. Thirdly, the literature relating hospitalization frequency, morbidity and mortality due to cardiovascular causes and ozone concentration will be studied. The correlation between ozone level and occurrence of acute myocardial infarction will be eventually discussed.

  9. Diferentes ambientes e Osmocote® na produção de mudas de tamarindeiro (Tamarindus indica Different ambient and Osmocote® for growth of tamarind (Tamarindus indica fruits seedlings

    Vander Mendonça

    2008-04-01

    Full Text Available Objetivou-se com este trabalho avaliar os efeitos de diferentes ambientes e doses de Osmocote® na produção de mudas de tamarindeiro (Tamarindus indica L. Um experimento foi instalado no Pomar da Universidade Federal de Lavras-MG, empregando-se delineamento experimental em blocos casualizados, em esquema fatorial 3 x 4, com quatro repetições e cinco plantas por parcela. Os tratamentos se constituíram dos diferentes ambientes de formação de mudas (casa de vegetação, telado e a céu aberto e de quatro doses de Osmocote®: 0; 3; 6 e 9 kg m-3 de substrato. Avaliaram-se a altura da muda (cm, comprimento da raiz (cm, número de folhas/planta, matéria seca da parte aérea (g, matéria seca da raiz (g e a matéria seca total (g. Os resultados demonstraram que o Osmocote® (15-10-10 pode ser recomendado para a formação de mudas de tamarindo, em doses de até 6,0 kg.m-3. O ambiente a céu aberto foi o que proporcionou melhor qualidade às mudas.This work aimed to evaluate the effect of ambient and Osmocote® (15-10-10 doses on the production of tamarind fruits seedlings. An experiment was carried out in a nursery at Universidade Federal de Lavras, Brazil, arranged in a randomized complete block outline and a 3x4 factorial scheme, with four replications and five plants per plot. The treatments were constituted by greenhouse, nursery and exposed sky, using different dosages of Osmocote® (15-10-10 were 0; 3; 6 e 9 kg m-3 of substrate. Seedling growth, height, number of leaves, aerial part, root and total dry matter were evaluated. The results showed that of Osmocote® (15-10-10 can be recommended for the formation of tamarind seedlings, at doses of until 6 kg m-3. Sky exposing was the one which provided better quality to the seedlings.

  10. Three days after a single exposure to ozone, the mechanism of airway hyperreactivity is dependent on substance P and nerve growth factor

    Verhein, Kirsten C.; Hazari, Mehdi S.; Moulton, Bart C; Jacoby, Isabella W.; Jacoby, David B.; Fryer, Allison D.

    2010-01-01

    Ozone causes persistent airway hyperreactivity in humans and animals. One day after ozone exposure, airway hyperreactivity is mediated by release of eosinophil major basic protein that inhibits neuronal M2 muscarinic receptors, resulting in increased acetylcholine release and increased smooth muscle contraction in guinea pigs. Three days after ozone, IL-1β, not eosinophils, mediates ozone-induced airway hyperreactivity, but the mechanism at this time point is largely unknown. IL-1β increases ...

  11. Ozone modeling

    Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO2), 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 NOx 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 NOx coordinates of the point, known as the NMOC/NOx ratio. Results obtained by the described model are presented

  12. Ozone decomposition

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    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. PMID:26109880

  13. Initial field evaluation of the Harvard active ozone sampler for personal ozone monitoring.

    Geyh, A S; Roberts, P T; Lurmann, F W; Schoell, B M; Avol, E L

    1999-01-01

    Assessing personal exposure to ozone has only been feasible recently with the introduction of passive ozone samplers. These devices are easy to use, but changes in air velocity across their collection surfaces can affect performance. The Harvard active ozone sampler (AS) was developed in response to problems with the passive methods. This active sampler has been tested extensively as a microenvironmental sampler. To test for personal sampling, 40 children attending summer day-camp in Riverside, California wore the active ozone sampler for approximately 2.6 h on July 19 and 21, 1994, when ozone concentrations were about 100 ppb and 140 ppb, respectively. The children spent 94-100% of the sampling period outside, staying within a well-defined area while participating in normal camp activities. Ambient ozone concentrations across this area were monitored by two UV photometric ozone monitors. The active sampler was worn in a small backpack that was also equipped with a passive ozone sampler. Device precision, reported as the percent difference between duplicate pairs of samplers, was +/- 3.7% and +/- 4.2% for the active and passive samplers, respectively. The active sampler measured, on average, 94.5 +/- 8.2% of the ambient ozone while the passive samplers measured, on average, 124.5 +/- 18.8%. The samplers were worn successfully for the entire sampling period by all participating children. PMID:10321353

  14. Ambient Space and Ambient Sensation

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...... aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness...

  15. Ozone as an ecotoxicological problem

    Mortensen, L. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark)

    1996-11-01

    Ozone is quantitatively the dominating oxidant in photochemical air pollution. Other compounds like hydrogen peroxide, aldehydes, formate, peroxyacetyl nitrate (PAN) and nitrogen dioxide are present too, and several of these are known to be phytotoxic, but under Danish conditions the concentration of these gases are without significance for direct effects on vegetation. Therefore, it is the effects of ozone on plant growth that will be described below. (EG) 65 refs.

  16. Experimental studies on ozonation of ethylenethiourea

    Xinyu Dong; Junwang Meng; Bo Yang; Yang Zhang; Jie Gan; Xi Shu; Jinian Shu

    2011-01-01

    The experimental study on ozonation of ethylenethiourea (ETU) is conducted. The reaction of gas-phase ETU with 0.63 × l06 mol/L ozone is carried out in a 200-L reaction chamber. The secondary organic aerosol (SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size (SMPS). The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days. The ozonation of dry ETU particles, ETU-contained water droplets and ETU aqueous solution is investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUVATOFMS). The formation of 2-imidazoline is observed in the ozonation of dry ETU particles and ETU-contained water droplets. The formation of 2-imidazoline and ethylenerea is observed in the ozonation of ETU aqueous solution.

  17. [Preliminary study on suitability of ozone sterilization in traditional Chinese medicine and its preparation].

    Hu, Yan-jun; Wang, Ya-qi; Wu, Zhen-feng; Lan, Ji-ping; Zhang, Li-guo; Yang, Ming

    2015-08-01

    Microbial contamination, growth and reproduction have a great influence on the quality of traditional Chinese medicine (TCM) and its preparation. TCM may be polluted by microbial in the production process due to ambient air, facilities and appliances and operating personnel, which affects the quality and efficacy of the final product. The GMP certification inspection standard of TCM manufacturing enterprises clearly established: "Sterilization methods of Chinese herbal medicine, intermediate products, finished products should follow the principle whether or not to change its quality", "TCM powder that used as medicine directly should follow the principle whether to do microbiological examinations". So it's particularly important for product quality, corporate energy consumption and its efficiency to choose the scientific and effective sterilization techniques and methods. Ozone is a kind of safe, environmentally friendly, efficient and no residue emerging sterilization technology. It has been widely applied in various fields of medical and health care and production and living. This paper mainly analyzed the ozone sterilization technology of TCM, aiming to explore the principle of ozone sterilization, the advantages, application status and existing problems and so on. The management regulations and implementation rules of ozone sterilization were summarized to make sterilization of Chinese medicine in the production, management, quality control and other aspects standardized, reasonable and scientific, and to provide the theoretical reference of the ozone sterilization technology for TCM and its preparation. PMID:26790281

  18. Ozone pollution and ozone biomonitoring in European cities Part II. Ozone-induced plant injury and its relationship with descriptors of ozone pollution

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

    2006-01-01

    Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic......-exposed sites. The tobacco plants were exposed to ambient air for biweekly periods at up to 100 biomonitoring sites from 2000 to 2002. Special emphasis was placed upon methodological standardisation of plant cultivation, field exposure and injury assessment. Ozone-induced leaf injury showed a clearly increasing...... gradient from northern and northwestern Europe to central and southern European locations. The strongest ozone impact occurred at the exposure sites in Lyon and Barcelona, while in Edinburgh, Sheffield, Copenhagen and Düsseldorf only weak to moderate ozone effects were registered. Between-site differences...

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

    Hofer, Nora; Alexou, Maria [Institute of Forest Botany and Tree Physiology, Chair of Tree Physiology, Albert-Ludwigs-University, Georges-Koehler-Allee 053/054, D-79110 Freiburg (Germany); Heerdt, Christian [Bioclimatology and Air Pollution Research, Department of Ecology, Technische Universitaet Muenchen, Life Science Center Weihenstephan, Am Hochanger 13, 85354 Freising (Germany); Loew, Markus [Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Werner, Herbert [Bioclimatology and Air Pollution Research, Department of Ecology, Technische Universitaet Muenchen, Life Science Center Weihenstephan, Am Hochanger 13, 85354 Freising (Germany); Matyssek, Rainer [Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Rennenberg, Heinz [Institute of Forest Botany and Tree Physiology, Chair of Tree Physiology, Albert-Ludwigs-University, Georges-Koehler-Allee 053/054, D-79110 Freiburg (Germany); Haberer, Kristine [Institute of Forest Botany and Tree Physiology, Chair of Tree Physiology, Albert-Ludwigs-University, Georges-Koehler-Allee 053/054, D-79110 Freiburg (Germany)], E-mail: kristine.haberer@biologie.uni-freiburg.de

    2008-07-15

    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{sub 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.

  20. US EPA Region 9 8-Hour Ozone Designated Areas

    U.S. Environmental Protection Agency — Polygon feature class of Nonattainment Areas for 2008 NAAQS 8 Hour Ozone. Nonattainment areas are geographic areas which have not met National Ambient Air Quality...

  1. US EPA Region 9 1-Hour Ozone NAAQS Designations

    U.S. Environmental Protection Agency — Esri polygon shapefile of 1-hour ozone designated areas in US EPA Region 9. Nonattainment areas are geographic areas which have not met National Ambient Air Quality...

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

    Rozema, Jelte [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands)]. E-mail: jelte.rozema@ecology.falw.vu.nl; Boelen, Peter [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands); Blokker, Peter [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands)

    2005-10-15

    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.

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

    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. Ozone and Pulmonary Innate Immunity

    Hollingsworth, John W.; Kleeberger, Steven R.; Foster, W. Michael

    2007-01-01

    Ambient ozone (O3) is a commonly encountered environmental air pollutant with considerable impact on public health. Many other inhaled environmental toxicants can substantially affect pulmonary immune responses. Therefore, it is of considerable interest to better understand the complex interaction between environmental airway irritants and immunologically based human disease. The innate immune system represents the first line of defense against microbial pathogens. Intact innate immunity requ...

  5. Ambient Sensors

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under th

  6. Det ambiente

    Schmidt, Ulrik

    Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...

  7. Ambient Sensors

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under the GNU LGPL licence version 3 or higher.

  8. Growth kinetics and long-term stability of CdS nanoparticles in aqueous solution under ambient conditions

    The ubiquity of naturally occurring nanoparticles in the aquatic environment is now widely accepted, but a better understanding of the conditions that promote their formation and persistence is needed. Using cadmium sulfide (CdS) as a model metal sulfide species, thiolate-capped CdS nanoparticles were prepared in the laboratory to evaluate how aquatic conditions influence metal sulfide nanoparticle growth and stability. This work examines CdS nanoparticle growth directly in aqueous solution at room temperature by utilizing the size-dependent spectroscopic properties of semiconductors detectable by UV/vis. CdS nanoparticle growth was governed by oriented attachment, a non-classical mechanism of crystallization in which small precursor nanoparticles coalesce to form larger nanoparticle products. Nanoparticle growth was slowed with increasing capping agent and decreasing ionic strength. In addition to examining the short-term (hours) growth of the nanoparticles, a long-term study was conducted in which cysteine-capped CdS nanoparticles were monitored over 3 weeks in solutions of various ionic strengths. The long-term study revealed an apparent shift from small nanoparticles to nanoparticles twice their original size, suggesting nanoparticle growth may continue through oriented attachment over longer time scales. High-ionic strength solutions resulted in salt-induced aggregation and eventual settling of nanoparticles within days, whereas low-ionic strength solutions were stable against settling over the course of the experiment. Sulfide recovery from cysteine-capped CdS nanoparticles as acid volatile sulfide was nearly quantitative after 2 weeks in fully oxygenated water, demonstrating significantly slowed oxidation of sulfide when complexed to Cd(II) within CdS nanoparticles. The nanoparticles were also shown to be resistant to oxidation by Fe(III) (hydr)oxide. This study illustrates that aggregation, rather than chemical oxidation, is likely more important to the

  9. Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains

    Nielsen, Birte Lindstrøm

    2012-01-01

    Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity...... in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and...... and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest...

  10. Multi-morphological growth of nano-structured In{sub 2}Se{sub 3} by ambient pressure triethylene glycol based solution syntheses

    Li, Tongfei; Wang, Jian; Lai, Junyun; Zheng, Xuerong; Liu, Weiyan; Ji, Junna [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Liu, Hui [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401 (China); Jin, Zhengguo, E-mail: zhgjin@tju.edu.cn [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-10-15

    In{sub 2}Se{sub 3} nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized by a new, facile, ambient pressure triethylene glycol based solution chemical route using indium(III) chloride and selenium powder as precursors. The growing morphology, crystallization, chemical stoichiometry and light absorption property of the In{sub 2}Se{sub 3} products synthesized were characterized by TEM, HRTEM, FESEM, XRD, EDX and UV–vis–NIR measurements. Multi-morphological growth of the nano-structured In{sub 2}Se{sub 3} in triethylene glycol based solution syntheses with changed assisting agents and reaction styles was demonstrated. - Highlights: • Multimorphological growth of In{sub 2}Se{sub 3} was demonstrated based on solution chemistry. • A new, facile, low cost and fast air pressure TEG based solution process was used. • Nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized. • Morphology, crystallization, stoichiometry and light absorption was characterized. • Solution growth of β-In{sub 2}Se{sub 3} nanosheets was firstly reported by this submission.

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

    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

  12. Det Ambiente

    Schmidt, Ulrik

    Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...

  13. Influence of Feeding Enzymatically Hydrolyzed Yeast Cell Wall on Growth Performance and Digestive Function of Feedlot Cattle during Periods of Elevated Ambient Temperature

    Salinas-Chavira, J.; Arzola, C.; González-Vizcarra, V.; Manríquez-Núñez, O. M.; Montaño-Gómez, M. F.; Navarrete-Reyes, J. D.; Raymundo, C.; Zinn, R. A.

    2015-01-01

    In experiment 1, eighty crossbred steers (239±15 kg) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h temperature humidity index averaged 80, EHY increased dry matter intake (DMI) (linear effect, p0.10) on carcass characteristics. In experiment 2, four Holstein steers (292±5 kg) with cannulas in the rumen and proximal duodenum were used in a 4×4 Latin Square design experiment to evaluate treatments effects on characteristics of ruminal and total tract digestion in steers. There were no treatment effects (p>0.10) on ruminal pH, total volatile fatty acid, molar proportions of acetate, butyrate, or estimated methane production. Supplemental EHY decreased ruminal molar proportion of acetate (p = 0.08), increased molar proportion of propionate (p = 0.09), and decreased acetate:propionate molar ratio (p = 0.07) and estimated ruminal methane production (p = 0.09). It is concluded that supplemental EHY may enhance DMI and ADG of feedlot steers during periods of high ambient temperature. Supplemental EHY may also enhance ruminal fiber digestion and decrease ruminal acetate:propionate molar ratios in feedlot steers fed steam-flaked corn-based finishing diets. PMID:26194225

  14. Effect of different arbuscular mycorrhizal fungi on growth and physiology of maize at ambient and low temperature regimes

    Chen, Xiaoying; Song, Fengbin; Liu, Fulai;

    2014-01-01

    The effect of four different arbuscular mycorrhizal fungi (AMF) on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a...

  15. Ozonation of sediments from an urban lake: an exploratory investigation

    F. A Lage Filho

    2011-09-01

    Full Text Available An exploratory investigation was conducted on the effects of application of ozone on the removal of organic and inorganic contaminants and the reduction of settleable solids in urban lake sediments. Homogenized sediment samples were treated in a batch reactor with an external recirculation loop and ozone feed from a Venturi injector. The ozone generating system was fed with ambient air with small footprint and operational simplicity. Ozone mass application (g/h and contact time (min were varied over wide ranges during testing. The effects of the ozone mass applied per unit time and the contact time on contaminant removal efficiencies were analyzed and a trade - off between the costs of ozonation and of solids treatment and disposal was proposed. The minimum ozone mass application required for total contaminant removal apparently depended on the type of organic contaminant present. An apparent influence of inorganic contaminant speciation on the removal efficiency was found and discussed.

  16. Growth of ponderosa pine seedlings as affected by air pollution

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

    The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

  17. Ozone depletion zone and ozone smog. Ozone chemistry fundamentals

    This book elucidates the fundamentals of the ozone theory. The knowledge verified through measurements is compiled, and the gaps in the knowledge of ozone are defined. While the knowledge of ozone appears to be well-established the gaps in the knowledge are responsible for uncertainties. Measurement methods for determination of the atmospheric concentration of ozone are described. Details are given about the basic processes of atmospheric ozone formation and ozone depletion and about the role of CFC. The factors which determine ozone concentrations in the southern hemisphere are described first because South Pole ozone formation processes, in spite of their complexity, are not as complex as North Pole ozone formation processes. The differences between these processes in the two polar regions are described. (orig.)

  18. Ambient Gestures

    Karam, Maria; Hare, Jonathon; Lewis, Paul; schraefel, m.c.

    2006-01-01

    We present Ambient Gestures, a novel gesture-based system designed to support ubiquitous ‘in the environment’ interactions with everyday computing technology. Hand gestures and audio feedback allow users to control computer applications without reliance on a graphical user interface, and without having to switch from the context of a non-computer task to the context of the computer. The Ambient Gestures system is composed of a vision recognition software application, a set of gestures to be p...

  19. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration

    McGrath, Justin M., E-mail: jmcgrath@illinois.ed [Department of Plant Biology, University of Illinois, Urbana-Champaign, 190 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States); Karnosky, David F., E-mail: karnosky@mtu.ed [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Ainsworth, Elizabeth A., E-mail: lisa.ainsworth@ars.usda.go [Department of Plant Biology, University of Illinois, Urbana-Champaign, 190 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States); USDA ARS Photosynthesis Research Unit, 147 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States)

    2010-04-15

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO{sub 2}]) and elevated ozone concentration ([O{sub 3}]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO{sub 2}] and [O{sub 3}] predicted for approx2050. The responses of two clones were compared during the first month of spring leaf out when CO{sub 2} fumigation had begun, but O{sub 3} fumigation had not. Trees in elevated [CO{sub 2}] plots showed a stimulation of leaf area index (36%), while trees in elevated [O{sub 3}] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO{sub 2}], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO{sub 2}]; however, the two clones responded differently to long-term growth at elevated [O{sub 3}]. The O{sub 3}-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O{sub 3}] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O{sub 3}] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O{sub 3}], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO{sub 2}] and suppressed by elevated [O{sub 3}] in aspen (Populus tremuloides).

  20. Substrate Utilization by an Oxalate-Consuming Spirillum Species in Relation to Its Growth in Ozonated Water

    van der Kooij, D.; Hijnen, W. A. M.

    1984-01-01

    The nutritional versatility of a vibrio-shaped, oxalate-utilizing isolate, strain NOX, obtained from tap water supplied with low concentrations of formate, glyoxylate, and oxalate, was determined by growth experiments with low-molecular-weight carbon compounds at high (grams per liter) and very low (micrograms per liter) concentrations. The organism, which was identified as a Spirillum species, appeared to be specialized in the utilization of a number of carboxylic acids. Yields of 2.9 × 106 ...

  1. Stem juice production of the C4 sugarcane (Saccharum officinarum)is enhanced by growth at double-ambient CO2 and high temperature

    Four sugarcane cultivars were grown for three months in sunlit greenhouses under [CO2] of 360 (ambient) and 720(doubled) ppm and at temperatures (T) of 1.5 (near ambient) and 6.0C higher than outside ambient T. Leaf area, stem juice, plant biomass, leaf CO2 exchange rate (CER) and activities of PEP ...

  2. The Antarctic Ozone Hole

    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…

  3. Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example

    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

  4. Effects of ambient background gases on YBCO plume propagation under film growth conditions: Spectroscopic, ion probe, and fast photographic studies

    The formation, composition, and propagation of KrF laser-produced plasmas from Y1Ba2Cu3O7-x have been studied with emphasis on topics relevant to film growth by pulsed-laser deposition. Spatially and temporally resolved, high-resolution optical absorption and emission spectroscopy, fast ion probes, and fast photography [obtained with a gated, image-intensified CCD array detector (ICCD)] are employed to investigate both emitting and non-emitting species in the laser plume as well as the overall shape and propagation of the laser plasma in background gases of oxygen and xenon. Transient optical absorption spectroscopy is applied to study the composition of the plume of ejected material from the dense layer near the target surface to distances of several centimeters. Optical absorption persists long after the decay of plasma fluorescence, indicating a slower component to plume transport. The absorption of YO formed by YBCO ablation in vacuum and by-yttrium ablation in oxygen is presented. Fast electric ion probes are utilized to measure velocities and total collected charge of the positive ions in the expanding YBCO laser plasma from near-threshold, vacuum conditions into the high fluence, background gas conditions utilized for thin-film growth. The exponential attenuation of the positive ion flux transmitted through 50--300 mTorr background oxygen is measured and used to define an attenuation coefficient. The showing of the laser plasma and formation of shock structures due to gas collisions is studied by ion probe measurements and fast ICCD photography. A comparison between shock wave propagation and drag models is presented to describe the arrival time and shape of the ion probe current waveform with distance. 11 refs, 11 figs

  5. In situ laser ablation plasma diagnostics in the film growth regime-effects of ambient background gases

    This paper reports on the propagation of the laser-induced plasma formed by KrF irradiation of Y1Ba2Cu3O7 characterized in background pressures of oxygen and argon typically used for thin film growth. The ion current transmitted through the background gases was recorded along the normal to the irradiated pellet as a function of distance in order to measure the decreasing velocity and magnitude of the expanding plasma current due to collisional slowing and attenuation of the laser plume. The integrated ion charge delivered to a substrate at low pressures can be described by elastic scattering giving a general integral cross sections of σc [O2] = 3.2 x 10-16 cm2 and σc [Ar] = 2.7 x 10-16 cm2. At higher pressures, inelastic scattering leads to increased recombination and reactive conversion of ions indicated by increased fluorescence of all the species, which becomes dominated by fluorescence of YO and BaO. Spatially resolved fluorescence measurements indicate that the luminous boundary to the plasma follows a weak shock front which coincides with the ion flux propagation. The ion transmission is found to drop exponentially with distance and background pressure, in agreement with a simple scattering model which yields general scattering cross sections for ion-argon σi-Ar = 2.1 x 10-16 cm2 and ion-oxygen σi-O2 = 2.3 x 10-16 cm2 interactions in background pressures up to 300 mTorr. The general features of the plume deceleration are described in terms of a drag force model alloys

  6. Estimating the Influence of Oil and Gas Emissions on Urban Ozone and Associated Health Risks

    Capps, S.; Nsanzineza, R.; Turner, M. D.; Henze, D. K.; Zhao, S.; Russell, M. G.; Hakami, A.; Milford, J. B.

    2015-12-01

    Tropospheric ozone (O3) degrades air quality, impacting human health and public welfare. The National Ambient Air Quality Standard (NAAQS) is designed to limit these impacts, but certain areas in the continental U.S. exceed this standard. Mitigating O3 NAAQS exceedances by designing emissions controls can be complicated in urban areas because of the long-range transport of ozone and its gaseous precursors as well as the complex mix of local emissions sources. Recent growth of unconventional oil and gas development near urban areas in Colorado, Texas, and the northeastern corridor has exacerbated this problem. To estimate the contribution of emissions from oil and gas development to urban O3 issues, we apply the CMAQ adjoint, which efficiently elucidates the relative influence of emissions sources on select concentration-based metrics. Specifically, the adjoint is used to calculate the spatially-specific relative contributions of emissions of oxides of nitrogen (NOx) and volatile organic compounds (VOCs) throughout the continental U.S. to O3 NAAQS exceedances and to ozone-related health risks in select urban areas. By evaluating these influences for different urban areas, including one in California that has been managing air quality with adjacent oil and gas development for a longer period of time, we are able to compare and contrast the emissions control strategies that may be more effective in particular regions. Additionally, the resulting relationships between emissions and concentrations provide a way to project ozone impacts when measurements provide refined estimates of emissions from this sector.

  7. Ambient intelligence

    Sanders, David; Gegov, Alexander

    2006-01-01

    This paper considers some history and the state of the art of Ambient Intelligence and from that seeks to identify new topics and future work. Ubiquitous computing, communications, human-centric computer interaction, embedded systems, context awareness, adaptive systems and distributed device networks are considered.

  8. Ambient intelligence

    Weber, W; Aarts, E

    2005-01-01

    Addresses ambient intelligence used to support human contacts and accompany an individual''s path through the complicated modern world, from applications that are imminent, since they use essentially existing technologies, to ambitious ideas whose realization is still far away, due to major unsolved technical challenges.

  9. Contribution of some ozone depleting substances (ODS) and greenhouse gases (GHGs) on total column ozone growth at Srinagar (34°N, 74.8°E), India

    Jana, P. K.; Saha, D. K.; Sarkar, D.

    2013-02-01

    A critical analysis has been made on the contribution of CFC-11, CFC-12, CFC-113, CH3Cl, CH3Br, CCl4, CH3CCl3, HCFCs, halons, WMO (World Meteorological Organization) minor constituents, CH4, N2O and water vapour to the variation of total column ozone (TCO) concentration at the station in Srinagar (34°N, 74.8°E), India from 1992 to 2003. With the implementation of Montreal Protocol, though the concentrations of CFC-11, CFC-113, CH3Cl, CH3Br, CCl4 and CH3CCl3 had decreased, the concentrations of CFC-12, HCFCs, halons, WMO minor constituents, CH4, N2O and water vapour had increased, as a result of which TCO had risen from 1992 to 2003 at the above station. The nature of yearly variations of concentrations of the above ozone depleting substances and GHGs as well as ozone has been presented. Possible explanations for build-up of TCO have also been offered.

  10. Influence of ambient and enhanced ultraviolet-B radiation on the plant growth and physiological properties in two contrasting populations of Hippophae rhamnoides

    Two contrasting sea buckthorn (Hippophae rhamnoides L.) populations from low and high altitude regions were employed to investigate the effects of prevailing and enhanced ultraviolet-B (UV-B) radiation on plant growth and physiological properties under a UVB-enhanced/exclusion system. The experimental design included three UV-B regimes, including excluded (-UVB), near-ambient (NA) and enhanced UV-B (+UVB) radiation. Compared with the control (-UVB), NA caused the formation of smaller but thicker plant leaves in both sea buckthorn populations, paralleled with significant increments of carotenoids and UV-absorbing compounds as well as improved water economy. NA also induced more biomass partition from shoot to root, but CO2 assimilation rate (A), photosynthetic area and biomass accumulation were unaffected. The low-altitude population seemed sensitive to +uvB, as indicated by the decreases in total biomass, A and ascorbic acid content (Asa, an antioxidant) compared with NA. However, little +UVB effect occurred on the high-altitude population, and we suggest that the higher tolerance of this population could be associated with its specific morphological and physiological characteristics, such as small but thick leaves and high-level of Asa content, as well as its greater physiological modification in response to NA, e.g., increases in protective compounds (carotenoids and UV-absorbing compounds) and improvement in water economy, in comparison to the low-altitude population, which form an effective adaptation strategy to enhanced UV-B stress

  11. The Pal pathway required for ambient pH adaptation regulates growth, conidiation, and osmotolerance of Beauveria bassiana in a pH-dependent manner.

    Zhu, Jing; Ying, Sheng-Hua; Feng, Ming-Guang

    2016-05-01

    The Pal/Rim pathway essential for fungal adaptation to ambient pH has been unexplored in Beauveria bassiana, a classic fungal entomopathogen. Here, we show the characterized Pal pathway comprising transcription factor PacC and upstream six Pal partners (PalA/B/C/F/H/I) in B. bassiana. Their coding genes were all transcribed most abundantly in standard wild-type culture under the alkaline condition of pH 9. Deletion of pacC or each pal gene resulted in a significant delay of culture acidification in a minimal broth (initial pH = 7.3). This delay concurred with altered accumulation levels of intra/extracellular organic acids and drastically depressed expression of some enzyme genes required for the syntheses of oxalic and lactic acids. Our deletion mutants except ΔpalI showed growth defects and maximal sensitivity to NaCl, KCl, LiCl, or sorbitol at pH 9, an alkaline condition leading to fragmented vacuoles in their hyphal cells exposed to osmotic stress. In these mutants, conidiation was significantly facilitated at pH 3 more than at pH 7 but suppressed slightly at pH 9. Mild virulence defects also occurred in the absence of pacC or any pal gene. These changes were restored by targeted gene complementation. Taken together, PacC and Pal partners regulate the growth, conidiation, and osmotolerance of B. bassiana in a pH-dependent manner, highlighting their vitality for the fungal pH response. PMID:26754817

  12. Ozone reaction with interior building materials: Influence of diurnal ozone variation, temperature and humidity

    Rim, Donghyun; Gall, Elliott T.; Maddalena, Randy L.; Nazaroff, William W.

    2016-01-01

    Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect health and comfort. Reactive uptake of ozone has been characterized for many building materials; however, scant information is available on how diurnal variation of ambient ozone influences ozone reaction with indoor surfaces. The primary objective of this study is to investigate ozone-surface reactions in response to a diurnally varying ozone exposure for three common building materials: ceiling tile, painted drywall, and carpet tile. A secondary objective is to examine the effects of air temperature and humidity. A third goal is to explore how conditioning of materials in an occupied office building might influence subsequent ozone-surface reactions. Experiments were performed at bench-scale with inlet ozone concentrations varied to simulate daytime (ozone elevated) and nighttime (ozone-free in these experiments) periods. To simulate office conditions, experiments were conducted at two temperatures (22 °C and 28 °C) and three relative humidity values (25%, 50%, 75%). Effects of indoor surface exposures were examined by placing material samples in an occupied office and repeating bench-scale characterization after exposure periods of 1 and 2 months. Deposition velocities were observed to be highest during the initial hour of ozone exposure with slow decrease in the subsequent hours of simulated daytime conditions. Daily-average ozone reaction probabilities for fresh materials are in the respective ranges of (1.7-2.7) × 10-5, (2.8-4.7) × 10-5, and (3.0-4.5) × 10-5 for ceiling tile, painted drywall, and carpet tile. The reaction probability decreases by 7%-47% across the three test materials after two 8-h periods of ozone exposure. Measurements with the samples from an occupied office reveal that deposition velocity can decrease or increase with time

  13. Theoretical modelling of Staphylococcus aureus growth in a cooked meat product kept at ambient temperature using temperature profiles of selected Mexican cities Modelagem teórica de crescimento de Staphylococcus aureus em um produto à base de carne cozida deixada à temperatura ambiente, usando perfis de temperatura de cidades do México

    Rosa Baeza

    2009-03-01

    Full Text Available A theoretical model is used to predict the growth of Staphylococcus aureus in a pasteurized meat product kept at ambient temperatures for several hours. For this purpose, the temperature profiles of some cities of Mexico were combined with literature data on the kinetics of S. aureus growth. As shown by theoretical predictions, if the food is kept at ambient temperature, the average daily temperature may not give accurate predictions.Um modelo teórico é utilizado para prever o crescimento de Staphylococcus aureus em um produto à base de carne (pasteurizado deixado por várias horas à temperatura ambiente. Para isso, perfis de temperatura de algumas cidades do México foram combinados com resultados de literatura sobre a cinética de crescimento de S. aureus. Como demonstrado por previsões teóricas, se o alimento é deixado à temperatura ambiente, a utilização da média diária da temperatura pode não dar previsões exatas.

  14. Effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid supplementation on growth performance, indices of ascites syndrome, and antioxidant capacity of broilers reared at low ambient temperature

    Yang, G. L.; Zhang, K. Y.; Ding, X. M.; Zheng, P.; Luo, Y. H.; Bai, S. P.; Wang, J. P.; Xuan, Y.; Su, Z. W.; Zeng, Q. F.

    2016-01-01

    This study examined the effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) supplementation on growth performance, antioxidant capacity, and ascites syndrome (AS) in broilers reared at low ambient temperature (LAT) from 7 to 28 days of age. Eight hundred 7-day-old broilers were randomly assigned to two ambient temperatures (LAT and normal ambient temperature [NAT]), four supplemental DL-HMTBA levels (0.17, 0.34, 0.51, and 0.68 %) of the basal diet in a 2 × 4 factorial arrangement (ten replicate pens; ten birds/pen). LAT and NAT indicate temperatures of 12-14 and 24-26 °C in two chambers, respectively, and broilers were reared at these temperatures from 7 to 28 days of age. LAT significantly decreased body weight gain (P recommended supplemental of DL-HMTBA level was 0.46 %.

  15. Secondary maxima in ozone profiles

    R. Lemoine

    2004-01-01

    International audience Ozone profiles from balloon soundings as well as SAGE II 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 seco...

  16. Ozone Hole Over Antarctica

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  17. Ozone disintegration kinetics in the reactor for tyres decomposition

    The results of theoretical and experimental research of ozone disintegration kinetics in the chemical reactor which is developed for decomposition of tyres in the ozone-air environment are presented. Analytical expression for dependence of ozone concentration in the reactor from time and from parameters of the task, such as volume speed of ozone-air mixture feed on a reactor input, concentration of ozone on the input to the reactor, volume speed of output of the used mixture, reactor size, and square of its internal surface is obtained. It is shown that at the same speed of ozone-air mixture pro rolling through the reactor, with growth of ozone concentration on the input, value of stationary concentration in the reactor grows, remaining always less than concentration on the input. It is also shown that at the same ozone concentration on the input, with growth of speed of ozone-air mixture pro rolling through the reactor, value of stationary ozone concentration in the reactor also grows, remaining always less than ozone concentration on the input. The ozone disintegration kinetics in the reactor in a wide range of speed of ozone-air mixture pro rolling through the reactor (0.15, 0.30, 0.45, 0.60 m3/hour) and various ozone concentration on the input (5, 10, 15, 20 g/m3) is experimentally studied. It is shown that experimental results with good accuracy coincide with the theoretical. Direct experiment showed the essential influence of the internal surface of the reactor on the ozone disintegration kinetics.

  18. Ambient intelligence

    Basten, Twan; de Groot, Harmke

    2007-01-01

    ""This book is truly an eye-opener as it is the first book that relates the dream scenarios of Ambient Intelligence quantitatively to the technical challenges and requirements of the huge distributed and interoperable embedded systems needed to implement AmI systems in the real world. This book is strongly recommended to a wide spectrum of engineers interested to embark in this rapidly emerging and fascinating technology."" (From the foreword by Hugo De Man, Professor K.U. Leuven and Senior Research Fellow IMEC)

  19. Tropospheric Ozone and Photochemical Smog

    Sillman, S.

    2003-12-01

    global background ozone can make the effects of local pollution events everywhere more acute, and can also cause ecological damage in remote locations that are otherwise unaffected by urban pollution. Ozone at the global scale is also related to greenhouse warming.This chapter provides an overview of photochemical smog at the urban and regional scale, focused primarily on ozone and including a summary of information about particulates. It includes the following topics: dynamics and extent of pollution events; health and ecological impacts; relation between ozone and precursor emissions, including hydrocarbons and nitrogen oxides (NOx); sources, composition, and fundamental properties of particulates; chemistry of ozone and related species; methods of interpretation based on ambient measurements; and the connection between air pollution events and the chemistry of the global troposphere. Because there are many similarities between the photochemistry of ozone during pollution events and the chemistry of the troposphere in general, this chapter will include some information about global tropospheric chemistry and the links between urban-scale and global-scale events. Additional treatment of the global troposphere is found in Volume 4 of this work. The chemistry of ozone formation discussed here is also related to topics discussed in greater detail elsewhere in this volume (see Chapters 9.10 and 9.12) and in Volume 4.

  20. Air pollution by ozone across Europe during summer 2010. Overview of exceedances of EC ozone threshold values for April-September 2010

    2011-06-15

    This report provides an evaluation of ground-level ozone pollution in Europe for April-September 2010, based on information submitted to the European Commission under Directive 2002/3/EC on ozone in ambient air. Since Members States have not yet finally validated the submitted data, the conclusions drawn in this report should be considered as preliminary. (Author)

  1. Air pollution by ozone across Europe during summer 2009. Overview of exceedances of EC ozone threshold values for April-September 2009

    2010-03-15

    This report provides an evaluation of ground-level ozone pollution in Europe for April-September 2009, based on information submitted to the European Commission under Directive 2002/3/EC on ozone in ambient air. Since Members States have not yet finally validated the submitted data, the conclusions drawn in this report should be considered as preliminary. (Author)

  2. Air pollution by ozone across Europe during summer 2008. Overview of exceedances of EC ozone threshold values for April-September 2008

    2009-07-01

    This report provides an evaluation of ground-level ozone pollution in Europe for April-September 2008, based on information submitted to the European Commission under Directive 2002/3/EC on ozone in ambient air. Since Members States have not yet finally validated the submitted data, the conclusions drawn in this report should be considered as preliminary. (au)

  3. Crescimento e qualidade de mudas de pinhão-manso produzidas em ambiente protegido Growth and quality of physic nut seedlings produced in greenhouse

    Janaina Paulino

    2011-01-01

    Full Text Available Devido ao recente Programa de Produção de Biocombustíveis do Brasil, o interesse comercial tem crescido em relação à produção de pinhão-manso (Jatropha curcas L.. Informações sobre esta cultura ainda são escassas, o que remete a necessidade de mais pesquisas que possam estabelecer condições de adaptabilidade desta cultura em diferentes condições. Neste contexto, realizou-se um experimento para estudar o crescimento e a qualidade das mudas de pinhão-manso, produzidas em ambiente protegido; as mudas foram monitoradas até o momento de serem transplantadas para o campo. Foi analisada a influência dos tipos e volumes de recipientes, juntamente com diferentes substratos e formas de adubação; o consumo de água também foi analisado durante o experimento. De acordo com os resultados, as melhores taxas de crescimento e qualidade de mudas até a condição de transplantio, foram obtidas com a combinação do substrato comercial, maior tubete e adubo de liberação lenta.There has been an increasing interest in the commercial production of physic nut (Jatropha curcas L. due to the recent Brazilian Program of Biofuel Production. Information on this crop is still scarce and more research is necessary to set the grounds of crop adaptability in different local conditions. An experiment was set up on this issue under greenhouse environment. Growth and quality of physic nut seedlings was monitored up to transplanting time. The influence of types and volumes of seedling containers was analysed along with different substrates and fertilization strategies. The water use was also detailed in the trial. Results showed the best achievements of growth rate and seedling quality, at appropriate transplanting time, were reached from the combination of the commercial substrate, largest containers and fertilizers of slow nutrient liberation.

  4. Quantifying the impact of current and future tropospheric ozone on tree biomass, growth, physiology and biochemistry: A quantitative meta-analysis

    The northern hemisphere temperate and boreal forests currently provide an important carbon sink; however, current tropospheric ozone concentrations ([O3]) and [O3] projected for later this century are toxic to trees and have the potential to reduce the carbon sink strength of these forests. This met...

  5. Leaf injury characteristics of grassland species exposed to ozone in relation to soil moisture condition and vapour pressure deficit

    A range of plant species typical of semi-natural grasslands were tested for their sensitivity to short-term ozone injury under normal and reduced irrigation, and in relationship to air vapour pressure deficit. Potted specimens of 24 herbs, legumes and grasses were exposed during two seasons to four O3 treatments in open-top chambers. The ozone treatments were: (a) charcoal-filtered air; (b) charcoal-filtered air plus ozone to match ambient levels; (c) charcoal-filtered air plus O3 to ambient levels 1.5 and (d) charcoal-filtered air with ozone added to twice ambient levels during selected episodes of 7–13 d. During these ozone episodes, half of the plants in each ozone treatment received reduced irrigation (dry treatment) while the rest was kept under full irrigation (wet treatment). Type and date of first occurrence of leaf injury were noted during individual growth periods. Plants were harvested three times per year, and the percentage of injured leaves was recorded. Depending on species, injury symptoms were expressed as flecking (O3-specific injury), leaf yellowing or anthocyanin formation. Carum carvi and most species of the Fabaceae family (Onobrychis sativa, Trifolium repens, Trifolium pratense) were found to be most responsive to O3, injury occurring after only a few days of exposure in treatment (b). An episodic reduction in irrigation tended to reduce the expression of O3-specific symptoms, but only in species for which a reduction in soil moisture potential and an associated reduction in stomatal conductance during the dry episodes were observed. In other species, the protection from O3 injury seemed to be of little importance. Using artificial neural networks the injury response of nine species was analysed in relation to Species, stomatal conductance, ozone as AOT40 (accumulated exposure above a threshold of 0.04 ppm for periods with global radiation ≥ 50 W m−2 (Fuhrer et al., 1997)), mean relative growth rate, air vapour pressure deficit and

  6. Antarctic Ozone Hole, 2000

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  7. Ozone mass transfer and kinetics experiments

    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.

  8. Ozone mass transfer and kinetics experiments

    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. Antarctic ozone depletion

    Antarctic ozone depletion is most severe during the southern hemisphere spring, when the local reduction in the column amount may be as much as 50 percent. The extent to which this ozone poor air contributes to the observed global ozone loss is a matter of debate, but there is some evidence that fragments of the 'ozone hole' can reach lower latitudes following its breakup in summer. Satellite data show the seasonal evolution of the ozone hole. A new dimension has been added to Antarctic ozone depletion with the advent of large volcanic eruptions such as that from Mount Pinatubo in 1991. (author). 5 refs., 1 fig

  10. Stratospheric ozone depletion

    The amount of stratospheric ozone and the reduction of the ozone layer vary according to seasons and latitudes. At present total and vertical ozone is monitored over all Austria. The mean monthly ozone levels between 1994 and 2000 are presented. Data on stratospheric ozone and UV-B radiation are published daily on the home page http: www.lebesministerium.at. The use of ozone depleting substances such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) is provided. Besides, the national measures taken to reduce their use. Figs. 2, Tables 2. (nevyjel)

  11. The Antarctic ozone hole

    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

  12. Tropospheric ozone and the environment II. Effects, modeling and control

    This was the sixth International Specialty Conference on ozone for the Air ampersand Waste Management Association since 1978 and the first to be held in the Southeast. Of the preceding five conferences, three were held in Houston, one in New England, and one in Los Angeles. The changing location continues to support the understanding that tropospheric ozone is a nationwide problem, requiring understanding and participation by representatives of all regions. Yet, questions such as the following continue to be raised over all aspects of the nation's efforts to control ozone. Are the existing primary and secondary National Ambient Air Quality Standards (NAAQS) for ozone the appropriate targets for the ozone control strategy, or should they be modified to more effectively accommodate new health or ecological effects information, or better fit statistical analyses of ozone modeling data? Are the modeling tools presently available adequate to predict ozone concentrations for future precursor emission trends? What ozones attainment strategy will be the best means of meeting the ozone standard? To best answer these and other questions there needs to be a continued sharing of information among researchers working on these and other questions. While answers to these questions will often be qualitative and location specific, they will help focus future research programs and assist in developing future regulatory strategies

  13. Contribution of some ozone depleting substances (ODS) and greenhouse gases (GHGs) on total column zone growth at Srinagar (34°N, 74.8°), India

    P K Jana; D K Saha; D Sarkar

    2013-02-01

    A critical analysis has been made on the contribution of CFC-11, CFC-12, CFC-113, CH2Cl, CH3Br, CCl4, CH3CCl3, HCFCs, halons, WMO (World Meteorological Organization) minor constituents, CH4, N2O and water vapour to the variation of total column ozone (TCO) concentration at the station in Srinagar (34°N, 74.8°E), India from 1992 to 2003. With the implementation of Montreal Protocol, though the concentrations of CFC-11, CFC-113, CH3Cl, CH3Br, CCl4 and CH3CCl3 had decreased, the concentrations of CFC-12, HCFCs, halons, WMO minor constituents, CH4, N2O and water vapour had increased, as a result of which TCO had risen from 1992 to 2003 at the above station. The nature of yearly variations of concentrations of the above ozone depleting substances and greenhouse gases as well as ozone has been presented. Possible explanations for build-up of TCO have also been offered.

  14. Effect of regular aerobic exercise with ozone exposure on peripheral leukocyte populations in Wistar male rats

    Afshar Jafari; Mohammad Ali Hosseinpour faizi; Fariba Askarian; Hassan Pourrazi

    2009-01-01

    • BACKGROUND: The immune system in endurance athletes may be at risk for deleterious effects of gasous pollutants such as ambient ozone. Therefore, this study was performed to assess the effect of regular aerobic exercise with ozone exposure on peripheral leukocytes populations in male Wistar rats.
    • METHODS: Twenty eight 8 weeks old rats were selected and randomly divided into four groups of ozone-u...

    • Rapid increases in tropospheric ozone production and export from China

      Verstraeten, Willem W.; Neu, Jessica L.; Williams, Jason E.; Bowman, Kevin W.; Worden, John R.; Boersma, K. Folkert

      2015-09-01

      Rapid population growth and industrialization have driven substantial increases in Asian ozone precursor emissions over the past decade, with highly uncertain impacts on regional and global tropospheric ozone levels. According to ozonesonde measurements, tropospheric ozone concentrations at two Asian sites have increased by 1 to 3% per year since 2000, an increase thought to contribute to positive trends in the ozone levels observed at North America’s West Coast. However, model estimates of the Asian contribution to North American ozone levels are not well-constrained by observations. Here we interpret Aura satellite measurements of tropospheric concentrations of ozone and its precursor NO2, along with its largest natural source, stratospheric ozone, using the TM5 global chemistry-transport model. We show that tropospheric ozone concentrations over China have increased by about 7% between 2005 and 2010 in response to two factors: a rise in Chinese emissions by about 21% and increased downward transport of stratospheric ozone. Furthermore, we find that transport from China of ozone and its precursors has offset about 43% of the 0.42 DU reduction in free-tropospheric ozone over the western United States that was expected between 2005 and 2010 as a result of emissions reductions associated with federal, state and local air quality policies. We conclude that global efforts may be required to address regional air quality and climate change.

    • OZONE UPTAKE OF DIFFERENT-SIZED BLACK CHERRY TREES IN HIGH- AND LOW-LIGHT ENVIRONMENTS

      Ozone uptake rates of different-sized black cherry trees located in both high and low light environments were calculated from measurements of ambient ozone concentration and stomatal conductance. he objective of the study was to determine how tree size and light conditions may di...

    • Ozone Trends Across the United States over a Period of Decreasing NOx and VOC Emissions

      In this work, we evaluate ambient ozone trends at urban, suburban, and rural monitoring sites across the United States over a period of decreasing NOx and VOC emissions (1998–2013). We find that decreasing ozone trends generally occur in the summer, in less urbanized areas,...

    • Prediction of lung function response for populations exposed to a wide range of ozone conditions

      Abstract Context: A human exposure-response (E-R) model that has previously been demonstrated to accurately predict population mean FEV1 response to ozone exposure has been proposed as the foundation for future risk assessments for ambient ozone. Objective: Fit the origi...

    • Ozone layer - climate change interactions. Influence on UV levels and UV related effects

      Kelfkens G; Bregman A; de Gruijl FR; van der Leun JC; Piquet A; van Oijen T; Gieskes WWC; van Loveren H; Velders GJM; Martens P; Slaper H; NOP; LPI; LLO

      2002-01-01

      Ozone in the atmosphere serves as a partially protective filter against the most harmful part of the solar UV-spectrum. Decreases in ozone lead to increases in ambient UV with a wide variety of adverse effects on human health, aquatic and terrestrial ecosystems and food chains. Human health effect

    • Ozone Layer Observations

      McPeters, Richard; Bhartia, P. K. (Technical Monitor)

      2002-01-01

      The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  1. Ozone layer tragedy

    A brief introduction is given on how the ozone layer formed and about the factors depleted ozone layer such as chloro bromo compounds and so on; then, it follows the processes which destroy the troposphere. The damaging effect of ultraviolet radiation is described. Finally,the action taken to reduce the depletion of ozone layer is presented

  2. Ambient air pollution and the fetus

    Kadriye Yurdakök

    2013-01-01

    There is a growing evidence on the hazards of ambient air pollution on fetal development. Several review articles have been published on the adverse fetal outcomes including low birth weight, preterm birth, small-for-gestational age, and congenital anomalies. Recent studies have linked ambient air pollution to gestational hypertension, and preeclampsia which may be related to the detrimental effect of ambient air pollution on placental growth and function. Short-term and long-term exposure to...

  3. Earth's ozone layer

    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

  4. Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield

    The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO2 and O3, alone and in combination. As compared to the plants grown in charcoal filtered air (ACO2), growth and yield of the plants increased under elevated CO2 (ECO2) and decreased under combination of ECO2 with elevated O3 (ECO2 + EO3), ambient O3 (ACO2 + AO3) and elevated O3 (EO3). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO3. Foliar starch and organic carbon contents increased under ECO2 and ECO2 + EO3 and reduced under EO3 and ACO2 + AO3. Foliar N content declined in all treatments compared to ACO2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO2 is not enough to counteract O3 impact, but elevated CO2 has potential to counteract the negative effects of future O3 level. -- Highlights: ► Elevated CO2 enhanced the growth and yield of palak. ► Ambient and elevated ozone reduced the growth and yield of the test plant. ► Elevated CO2 reduced negative effects of elevated O3 by reducing oxidative stress. ► Higher amelioration was recorded at elevated CO2 + O3 compared to ambient CO2 + O3. -- Predicted levels of CO2 have greater ameliorative potential against negative effects of elevated ozone compared to present day CO2 against ambient ozone

  5. Ozone pollution: rising concentrations despite French and EU efforts

    Ozone is the main indicator of photochemical pollution which is caused by a complex combination of primary pollutants formed by chemical reactions in the troposphere, in the presence of sunlight. These primary pollutants, otherwise known as precursors of ozone (nitrogen oxides, volatile organic compounds and carbon monoxide), are emitted both by natural sources and human activities. In urban areas, during the summer months, ozone is often the main cause of deterioration in air quality. Directive 2002/3/EC relating to ozone in ambient air entered into force on 9 September 2003, superseding the first ozone Directive (92/72/CE) of 21 September 1992. In the last 10 years, monitoring of ozone pollution has considerably progressed in France (the number of analysers has increased tenfold). Emissions of the ozone precursors fell significantly (-27%) between 1990 and 2000 in France as a result of combined efforts in all sectors of activity. However, between 1994 and 2002, ozone levels remained above the information threshold for the protection of human health and vegetation on average more than 100 days a year in rural areas and over 40 days a year in urban and peri-urban areas. Efforts undertaken both in France and other European countries aim to improve the situation and ensure compliance with the requirements of Directive 2002/3/EC. (author)

  6. Manifestation of solar activity processes in the Earth ozone layer

    Statistical analysis of total ozone and its vertical distribution was carried out on the base of data obtained by rocket soundings with the aim to reveal influence of solar activity. THe coherence between monthly mean total ozone data series for six latitudinal zones in the Northern Hemisphere and solar spots has weak but steady maxima for 9 and 13-15 years periods of oscillations. The value of coherence does not exceed 0.15 and growth to the higher latitudes. The analysis of ozone profiles for middle latitudes reveals the decrease in ozone concentration between 30-50 km for winter and increase for autumn. 20 refs.; 3 figs

  7. Ambient air pollution and low birthweight

    Pedersen, Marie; Giorgis-Allemand, Lise; Bernard, Claire;

    2013-01-01

    BACKGROUND: Ambient air pollution has been associated with restricted fetal growth, which is linked with adverse respiratory health in childhood. We assessed the effect of maternal exposure to low concentrations of ambient air pollution on birthweight. METHODS: We pooled data from 14 population...

  8. Measurement of Ground Level Ozone at Different Locations

    Yasmen A. Mustafa

    2012-01-01

    Full Text Available Problem statement: Ground level ozone is the most important index substance of photochemical smog. Photochemical smog is now observed in many urban and industrial centers around the world and it has become a common phenomenon in many large cities. Ozone is a most harmful pollutant for humans, in addition it plays an important role in damaging vegetation and materials. Therefore it becomes important to measure the ground level ozone at different locations especially in the center of cities. Approach: The ground level ozone concentration at different locations in Baghdad city was identified. Five different sites have been chosen to identify the ground level ozone concentration. Two sites were chosen as areas contained point source (power plant station in addition to high traffic load and the other three sites were chosen as areas containing heavy traffic only (line source. The measurement focuses on spring and fall because these periods display favorable meteorology to ozone formation. Results: During the research period the maximum values (peaks for ground level ozone concentration were observed in the fall: at Al-Za’afarania area 101ppb as an average, at Al-Dora 87 ppb as an average (which represent the point sources and at line source areas 48 ppb as an average. In spring, the peaks of ozone concentration observed to be at the same height, about 50 ppb for all sites. Conclusion: The results show that the effect of power plant stations in forming ozone is larger than traffic load. The comparison between the ground level ozone concentrations that measured during the research period in spring and fall and the Ambient Air Quality Standards (AAQS shows that: (1 No exceeded levels were observed in spring for all sites. (2 In the fall, the AAQS for ozone was exceeded in Al-Za’afarania area at 12: PM, 1: PM, 2: PM and 3: PM and in Al-Dora at 2: PM.

  9. In situ autumn ozone fumigation of mature Norway spruce - Effects on net photosynthesis

    Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2002-01-01

    Twelve cuvettes were installed on current year's twigs in the top of the canopy of a 35 years old Norway spruce stand in Denmark. From 10 to 16 hours, six of the cuvettes received 5-60 nl l(-1) ozone in addition to ambient air and six cuvettes received ambient air with a 40% reduced ozone...... was found that a mean increase in ozone concentration of 10 nl l(-1) reduced net photosynthesis with 7.4 %. This effect should be related to a pre-exposure during the season of AOT40 12.5 mul l(-1) h....

  10. Effect of ozone treatment on different cariogenic microorganisms in vitro.

    Fagrell, Tobias G; Dietz, Wolfram; Lingström, Peter; Steiniger, Frank; Norén, Jörgen G

    2008-01-01

    Ozone treatment has been presented and discussed in the literature, as one of the "new" ways to treat dental caries. The aim of this paper was to study the in vitro effect of ozone on some common oral microorganisms related to dental caries using scanning electron microscopy (SEM). The effect of ozone was tested on three different strains of mutans streptococci and one Lactobacillus strain. After exposure of bacteria to ozone treatment for 0 to 60 sec, cultivation on different chair side strips and agar plates took place. Preparation and performance of scanning electron analyses in a field emission scanning electron microscope at 10 kV was then carried out. It was found that gaseous ozone treatment for 20 seconds or more was effective to kill the different microorganisms in vitro. Treatment of 20, 40 and 60 seconds of ozone prevented the bacteria to grow on the different media. Treatment times shorter than 20 seconds resulted in varying results with a limited effect on bacterial growth for treatments of 5-10 sec, respectively. The difference between ozone-treated and untreated specimens was macroscopically readily discernable. None of the strains treated with ozone for 60 seconds showed any bacterial growth. Only samples with untreated bacteria could be found in the SEM analyses in form of large and high colonies. This study presents a clear result of the bactericide effect of ozon (in vitro) on four different strains of bacteria associated with dental caries. PMID:18973084