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1

Regional tree growth reductions due to ambient ozone: evidence from field experiments. [Populus deltoides; Robinia pseudoacacia  

Energy Technology Data Exchange (ETDEWEB)

Observations from extensive regions in Europe and North America suggest that many forests may be in early stages of ecosystem decline. The authors present experimental evidence from open-top chamber field studies indicating that ambient ozone at levels below the ambient air quality standard (235 ..mu..g m/sup -3/) causes significant reductions (19%) in the growth of sapling poplars (hybrid Populus). While ozone-induced reductions in growth have been observed under laboratory and greenhouse conditions, demonstration of this effect under field conditions is critical to the establishment of ozone standards. Growth reductions for Populus deltoides and Robinia pseudoacacia were not significant. Reductions in productivity and height growth occurred without visible symptoms of foliar injury and at ozone concentrations below current standards. If this invisible injury is typical in other tree species, the extent of ozone-induced forest damage may presently be greatly underestimated. Additional field studies on a regional basis are needed.

Wang, D.; Bormann, F.H.; Karnosky, D.F.

1986-11-01

2

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-02-01

3

Assessing plant response to ambient ozone: growth of ozone-sensitive loblolly pine seedlings treated with ethylenediurea or sodium erythorbate  

Energy Technology Data Exchange (ETDEWEB)

Ethylenediurea and sodium erythorbate increased growth of ozone-sensitive loblolly pine seedlings, after three growing seasons. - One-year-old seedlings from an ozone-sensitive half-sib family of loblolly pine (Pinus taeda L.) were transplanted into replicated plots in blocks in a large forest clearing near Nacogdoches, Texas. Seedlings were either non-treated (controls) or treated bi-weekly with foliar sprays of ethylenediurea (EDU), at 150, 300 or 450 ppm or sodium erythorbate (NaE), at 515, 1030, or 1545 ppm, for three growing seasons. Results from the final third year harvest indicated that both EDU and NaE increased all growth parameters, with significant differences only for EDU at 450 ppm. Both EDU and NaE would be useful for long-term studies on assessing the effects of ambient ozone on established native plants.

Manning, W.J.; Flagler, R.B.; Frenkel, M.A

2003-11-01

4

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

International Nuclear Information System (INIS)

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

2004-12-01

5

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

Energy Technology Data Exchange (ETDEWEB)

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.

Manning, W.J. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States)]. E-mail: wmanning@microbio.umass.edu; Cooley, D.R. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Tuttle, A.F. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Frenkel, M.A. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Bergweiler, C.J. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States)

2004-12-01

6

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

Energy Technology Data Exchange (ETDEWEB)

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.

Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Fernald Hall, 270 Stockbridge Rd., Amherst, MA 01003-9320 (United States)]. E-mail: wmanning@microbio.umass.edu

2005-10-15

7

Assessing the impact of ambient ozone on growth and productivity of two cultivars of wheat in India using three rates of application of ethylenediurea (EDU)  

Energy Technology Data Exchange (ETDEWEB)

Three rates of ethylenediurea were used to assess the impact of ambient ozone on growth and productivity of wheat (Triticum aestivum L) cultivars 'Malviya 533' (M 533) and 'Malviya 234' (M 234) at a suburban site near Varanasi, India, beginning in December. Wheat plants were treated with EDU at 0, 150, 300 and 450 ppm as soil drenches at 10-day intervals. EDU treatment affected plant growth, with effects varying with cultivar, age, and EDU concentration. Seed yield was improved for M 533 at 150 ppm EDU, while yield improved for M 234 at 300 and 450 ppm EDU. M 533 appears to be more resistant to ozone than M 234. Overall results confirmed that EDU is very useful in assessing the effect of ambient ozone in India. - EDU can be successfully used for assessing ozone injury to crops under ambient Indian conditions.

Tiwari, Supriya [Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, Madhoolika [Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherest, MA 01003-9298 (United States)]. E-mail: wmanning@microbio.umass.edu

2005-11-15

8

Assessing the impact of ambient ozone on growth and productivity of two cultivars of wheat in India using three rates of application of ethylenediurea (EDU)  

International Nuclear Information System (INIS)

Three rates of ethylenediurea were used to assess the impact of ambient ozone on growth and productivity of wheat (Triticum aestivum L) cultivars 'Malviya 533' (M 533) and 'Malviya 234' (M 234) at a suburban site near Varanasi, India, beginning in December. Wheat plants were treated with EDU at 0, 150, 300 and 450 ppm as soil drenches at 10-day intervals. EDU treatment affected plant growth, with effects varying with cultivar, age, and EDU concentration. Seed yield was improved for M 533 at 150 ppm EDU, while yield improved for M 234 at 300 and 450 ppm EDU. M 533 appears to be more resistant to ozone than M 234. Overall results confirmed that EDU is very useful in assessing the effect of ambient ozone in India. - EDU can be successfully used for assessing ozone injury to crops under ambient Indian conditions

2005-11-01

9

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

International Nuclear Information System (INIS)

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

2008-10-01

10

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

Energy Technology Data Exchange (ETDEWEB)

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 (O{sub 3}) 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 O{sub 3} 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 O{sub 3} 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.

Augustaitis, Algirdas [Lithuanian University of Agriculture, Forest Monitoring Laboratory, Studentu 13, LT-53362 Kaunas dstr. (Lithuania)], E-mail: algirdas.augustaitis@lzuu.lt; Bytnerowicz, Andrzej [USDA Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)

2008-10-15

11

INTERACTION OF SOIL MOISTURE STRESS AND AMBIENT OZONE ON GROWTH AND YIELDS OF SOYBEANS  

Science.gov (United States)

A field experiment was conducted in open-top chambers to determine how interactions of soil moisture stress and exposure to ozone may affect soybean yields. Cultivars Williams and Forrest were grown in 1982 and Williams & Corsoy in 1983. Five levels of O3-including charcoal-filte...

12

Assessing impacts of ambient ozone on selected crops; Schade aan gewassen door troposferisch ozon  

Energy Technology Data Exchange (ETDEWEB)

Tropospheric concentrations of the photochemical air pollutant ozone are steadily increasing in many industrialized countries. Plants of clover and bean were exposed to ambient air at four rural sites in the growing seasons of 1994 through 1996. The influence of ozone on visible injury, growth and yield was determined by comparing the response of plants treated with ethylene diurea (EDU) to that of untreated plants. EDU is an anti-oxidant that protects plants from ozone damage. A considerable degree of ozone-induced injury on both crop species has been observed at all sites. Injury varied between years and sites and the site-dependent pattern was similar for the species each year. Adverse effects of ozone on growth of clover and on pod yield in bean were observed each year. Concentrations of ambient ozone are sufficiently high to adversely affect yield of sensitive crops. 3 figs., 1 tab., 3 refs.

Tonneijck, A.E.G.; Van Dijk, C.J. [Afdeling Gewas- en Onkruidkunde, Instituut voor Agrobiologisch en Bodemvruchtbaarheidsonderzoek AB-DLO, Wageningen (Netherlands)

1997-03-01

13

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  

International Nuclear Information System (INIS)

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

2009-03-01

14

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)  

Energy Technology Data Exchange (ETDEWEB)

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.

Wang Xiaoke [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: wangxk@rcees.ac.cn; Zheng Qiwei [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Yao Fangfang [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Chen Zhan [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Feng Zhaozhong [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Manning, W.J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States)

2007-07-15

15

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.  

Science.gov (United States)

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 O(3) concentration varied from 41.65 to 54.2ppb 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 O(3). PMID:19070410

Singh, Poonam; Agrawal, Madhoolika; Agrawal, Shashi Bhushan

2009-03-01

16

The response of hybrid poplar to simulated ambient ozone episodes in open-top chambers  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the effect of ambient ozone episodes in southern Ontario on woody plants, this study looks at the growth and physiological responses of hybrid poplar (Populus deltoides x nigra) exposed to simulated ambient ozone episodes in open-top exposure chambers. The diurnal pattern of hourly ozone concentrations was designed to mimic ambient patterns. The effect of ozone episodes over a 32 day period on biomass accumulation was investigated. Repeated measurements were made of shoot height, shoot base diameter, leaf chlorophyll content and leaf net photosynthesis. Treatments were expressed as the desired peak concentration and the number of simulated ambient ozone episodes delivered. In the second two field seasons, the experimental design employed favored a larger number of treatments over the number of replications. Treatment was expressed as the cumulative dose of hourly ozone concentrations greater than 0.06 [mu]l 1[sup [minus]1]. On this basis, doses over the two seasons ranged from 0.08 to 9.88 [mu]l 1[sup [minus]1][center dot]h. The relationships between shoot height growth and biomass accumulation, and ozone dose were negative and linear. Ozone did not significantly affect plant development and shoot base diameter growth. Exposure to additional ozone appeared to suppress leaf chlorophyll content and leaf photosynthesis and resulted in accelerated aging of leaves. This research provided a useful protocol for studying the ozone response of hybrid poplar and demonstrated its sensitivity to ozone episodes under the climatic conditions of southern Ontario. All growth and physiological variables under study were affected but the development variables were not affected.

Dowsley, B.J.

1992-01-01

17

Measurements of cabin and ambient ozone on B747 airplanes  

Science.gov (United States)

In response to recent concerns over possibly high ozone levels in the cabins of aircraft flying in the stratosphere, simultaneous measurements of the cabin and ambient ozone levels have been made as part of the NASA Global Atmospheric Sampling Program. Examples of the data taken on commercially operated Boeing 747-100 and 747SP airplanes are given for selected flights, together with summary statistics of over 5600 observations. Cabin ozone levels vary with the ambient level and, for unmodified aircraft, are higher on the 747SP than on the 747-100. Modifications to the ventilation system of the 747SP reduced cabin ozone levels by varying amounts up to a factor of 14.

Nastrom, G. D.; Holdeman, J. D.; Perkins, P. J.

1980-01-01

18

Bioindicator plants for ambient ozone in Central and Eastern Europe  

International Nuclear Information System (INIS)

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

2004-07-01

19

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

International Nuclear Information System (INIS)

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

2013-09-01

20

Ambient levels of ozone reduce net photosynthesis in tree and crop species  

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted to measure the photosynthetic response of three crop and four tree species to realistic concentrations of ozone and (for tree species only) simulated acidic rain. The ozone concentrations were representative of those found in clean ambient air, in mildly to moderately polluted air such as occurs in much of the US during the summer, and in more heavily polluted air. However, the highest concentrations of ozone used were lower than those found regularly in the Los Angeles area. The mean pH of the simulated acid rain treatments ranged from more alkaline to much more acidic than the mean pH of precipitation in the US. Exposure to any increase in ozone reduced net photosynthesis in all species tested. In contrast, acidic rain had no negative effect on photosynthesis in tree species, and no interaction between ozone and acidic rain was observed. Ozone-induced reductions in photosynthesis were related to declines in growth or yield. Species with higher stomatal conductances and thus higher potential for pollutant uptake exhibited greater negative responses to similar ozone treatments. Since exposure to ozone concentrations typical of levels of the pollutant observed in the eastern half of the US reduced the rates of net photosynthesis of all species tested, reductions in net photosynthesis may be occurring over much of the eastern US. 31 references, 4 figures, 1 table.

Reich, P.B.; Amundson, R.G.

1985-11-01

 
 
 
 
21

Protection of plants from ambient ozone by applications of ethylenediurea (EDU): A meta-analytic review  

Energy Technology Data Exchange (ETDEWEB)

A meta-analysis was conducted to quantitatively assess the effects of ethylenediurea (EDU) on ozone (O{sub 3}) injury, growth, physiology and productivity of plants grown in ambient air conditions. Results indicated that EDU significantly reduced O{sub 3}-caused visible injury by 76%, and increased photosynthetic rate by 8%, above-ground biomass by 7% and crop yield by 15% in comparison with non-EDU treated plants, suggesting that ozone reduces growth and yield under current ambient conditions. EDU significantly ameliorated the biomass and yield of crops and grasses, but had no significant effect on tree growth with an exception of stem diameter. EDU applied as a soil drench at a concentration of 200-400 mg/L has the highest positive effect on crops grown in the field. Long-term research on full-grown tree species is needed. In conclusion, EDU is a powerful tool for assessing effects of ambient [O{sub 3}] on vegetation. - EDU effectively protect plants against ambient ozone.

Feng Zhaozhong, E-mail: zhzhfeng201@hotmail.co [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang Shuguang [Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Szantoi, Zoltan [School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611-0565 (United States); Chen Shuai; Wang Xiaoke [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

2010-10-15

22

Ambient hydrocarbon and ozone concentrations near a refinery. Final report  

Energy Technology Data Exchange (ETDEWEB)

An ambient air monitoring study to characterize airborne emissions from petroleum refineries was conducted near the Marathon oil refinery at Robinson, Illinois during June 17 - July 29, 1977. Ground-level sampling facilities and an airplane equipped with air pollutant monitoring instruments provided an integrated, three-dimensional monitoring network. Measurements made during the study included ozone, oxides of nitrogen, sulfur dioxide, methane, carbon monoxide, individual C2-C10 hydrocarbons, halocarbons, condensation nuclei, visual distance and various meteorological parameters.

Sexton, K.; Westberg, H.H.

1983-04-01

23

Compact automated ozone monitor for ambient air quality applications  

Energy Technology Data Exchange (ETDEWEB)

A compact, inexpensive, automated ozone monitor has been designed which may expect to see use in a wide variety of applications in the area of ambient air quality measurements. The monitor is based on a simple single-beam ultraviolet absorption photometer with a separate reference beam path. It is a novel design in that it is far smaller, lighter and cheaper than other ultraviolet absorption systems, while retaining the high performance the technique is known for. Another unique feature is the incorporation of a data logging capability. The instrument is capable of measuring down to 1 ppbv ozone with a precision of 0.3 ppbv and accuracy of 2%, with independent measurements made once every six seconds or faster. The instrument is well suited for unattended operation, and has excellent potential for use as an embedded unit. Several applications within the fields of indoor and outdoor air quality monitoring are foreseen, as well as use within ozone-generating equipment as a built-in safety monitor. Advantages over existing instruments for these applications include far smaller size and lower cost while maintaining high performance.

Bognar, J.A.; French, P.D.

1999-07-01

24

Response of green ash and white ash seedlings to ambient rain and ozone pollution in New Brunswick, New Jersey  

Energy Technology Data Exchange (ETDEWEB)

An experiment was conducted during the summers opf 1982-1984 at Cook College, New Brunswick, New Jersey, a site characterized by rainfall with an average pH of 4.2 and pollution episodes in which ozone exceeds 0.10 ppm. In 1982, two-year-old green ash (F. pennsylvanica) seedlings were grown in pots of unsterilized sandy loam in open top modules, half of which were supplied whith charcoal filtered air and half with ambient air. Within each module, half of the seedlings were protected during rain events by clear plastic umbrellas, and half were exposed to ambient rain. In 1983, the experimental design was modified. Green ash and white ash (F. americana) were used, and the ozone control was provided by weekly applications of a soil drench of 500 ppm ethylenediurea (EDU). Within each ozone treatment, half of the seedlings were protected during rain events by a plastic cover suspended over a wooden frame, and half were exposed to ambient rain. The white ash seedlings used in the 1983 experiment were maintained through the winter, and exposed to the same treatments in 1984. During the experiment, the amount of precipitation from each rain event was measured, and an equivalent amount of tap water was applied to the base of the seedlings not receiving ambient rain. From evidence accumulated over three years it is suggested that the growth of green and white ash is not, at least in the short term, adversely affected by ozone pollution or acid precipitation in New Brunswick, New Jersey. Although green ash foliage showed slight ozone injury one year and decreased chlorophyll content due to rain treatment in another year, these effects were not reflected in total growth. Ambient rain appeared to stimulate height growth and diameter growth of white ash.

Elliott, C.; Eberhardt, J.; Rebbeck, J.; Brennan, E.

1985-01-01

25

Chlorophyll content of soybean foliage in relation to seed yield and ambient ozone pollution  

Energy Technology Data Exchange (ETDEWEB)

A field test was conducted to determine if ozone pollution adversely affected the chlorophyll content and seed yield of soybean. Eight soybean cultivars were grown to maturity in test plots in central New Jersey; one-half of the plots was treated with an antioxidant (ethylene-diurea) to protect the plants from the effects of ambient ozone and one half was left untreated. Periodic chlorophyll measurements revealed no significant difference between EDU-treated and untreated plots during the major part of plant growth. The absence of a yield effect predicated on the normal chlorophyll contents was corroborated by actual total seed measurement. Our results did not support predictive models that forecast a significant yield reduction from a 7-h seasonal mean of 0.058 ppm 0/sub 3/, but agreed with results obtained previously in Maryland and Georgia.

Brennan, E.; Leone, I.; Greenhalgh, B.; Smith, G.

1987-12-01

26

Effects of increasing doses of sulfur dioxide and ambient ozone on tomatoes: plant growth, leaf injury, elemental composition, fruit yields, and quality  

Energy Technology Data Exchange (ETDEWEB)

Jet Star, an indeterminant tomato cultivar, was exposed to 0.011, 0.059, 0.118, 0.235, and 0.468 ppm SO/sub 2/ in open-top field chambers supplied with nonfiltered(NF) air and to 0.005, 0.113, and 0.466 ppm SO/sub 2/ in chambers with charcoal-filtered(CF) air. Treatments were given 5 hr/day, 5 days/wk, for a total of 57 days during July, August, and September. Ripe fruit yields were decreased 16% by O/sub 3/ in NF compared with CF air. The highest dose of SO/sub 2/ given in CF air reduced fruit yield by 18%. Ambient O/sub 3/ and the SO/sub 2/ treatments were additive in their effects on fruit yields. Significant reductions in fruit numbers were observed. Fruit quality was not measurably altered. A negative linear response for ripe fruit yield vs SO/sub 2/ exposure dose was demonstrated.

Heggestad, H.E.; Bennett, J.H.; Lee, E.H.; Douglass, L.W.

1986-01-01

27

Alternating measurement of ambient and cabin ozone concentrations in commercial jet aircraft.  

Science.gov (United States)

Ambient and cabin-air ozone concentrations were determined with an adapted commercial ozone analyzer installed in a KLM DC-10 from Amsterdam to Toronto and back. Cabin levels were detected directly and almost continuously; ambient levels were measured using a sampling system in which the ambient samples were converted to the cabin pressure at intervals of 13 min. A correlation is demonstrated between the ambient level, the cabin level, and the tropopause height. It was found that 70% of the ambient ozone concentration enters the cabin through the ventilation system, and about 50% of this concentration was measured 1.20 m above the cabin floor. For about 50% of the total flying time, the ozone level exceeded 200 parts per billion, by volume (ppb) in the cabin, with peak concentrations of about 600 ppb (TLV levels of 80--100 ppb apply in most IATA countries). Finally, medical and technical recommendations are made for future measurements. PMID:697666

van Heusden, S; Mans, L G

1978-09-01

28

Use of ethylenediurea to detect effects of ambient ozone on biomass production by clover cultivars  

Energy Technology Data Exchange (ETDEWEB)

Ozone-tolerant (NCR) and ozone-sensitive (NCS) clonal plants of ladino white clover (Trifolium repens) were grown in 15-liter pots filled with a peat/perlite artificial growing medium during the 1994 and 1995 growing seasons. All plants were exposed to ambient concentrations of ozone. Beginning the first day plants were in the field, and continuing at 7-day intervals until final harvests, each plant was sprayed with 300 ppm ethylenediurea (EDU). Foliar biomass harvests were made at 28-day intervals and dry weights of leaves/stems determined. Biomass weights for NCR were unaffected by EDU. EDU ameliorated the effects of ambient ozone on NCR plants, allowing detection of the effects of ozone on an ozone-sensitive clone of white clover.

Manning, W.; Johnson, M.; Frenkel, M. [Univ. of Massachusetts, Amherst, MA (United States)

1995-12-31

29

COTTON YIELD LOSSES AND AMBIENT OZONE CONCENTRATIONS IN CALIFORNIA'S SAN JOAQUIN VALLEY  

Science.gov (United States)

Based on controlled experiments and simulation modeling, ozone air pollution has been estimated to cause significant yield losses to cotton. he study reported here was conducted to verify losses for Acala cotton (Gossypium hirsutum L.'SJ2') along a gradient of ambient ozone (O3) ...

30

Field Testing of New Interference-Free Ambient Ozone Monitors  

Science.gov (United States)

Multibillion-dollar strategies control ambient air ozone (O3) levels in the U.S. so it is essential that the O3 measurements made for developing state implementation plans, assessing population risks, and determining compliance with regulations be accurate. The predominant U.S. regulatory method employed to monitor ambient O3 is ultraviolet (254 nm) photometry and many previous studies have demonstrated positive interferences associated with this technology. We evaluate two new humidity-controlled commercial instruments - a 2B Technology Model 211 ultraviolet O3 photometer that replaces its conventional MnO2 scrubber with gas-phase NO titration and a Teledyne-API Model 265E NO-O3 chemiluminescence monitor - both designed to minimize the aromatic organic, mercury, and water vapor interferences common to O3 photometers. New units were paired with conventional photometers sampling indoor, outdoor, and in-vehicle environments where populations spend most of their time. Overall, during the fixed-site monitor comparisons in Houston, TX, the three instruments were highly correlated (r2 ? 0.99) with regression slopes of 1.00 ± 0.01, and O3 averaged over the study period agreed within 1 ppb; however, U.S. O3 standard compliance depends on fourth highest annual daily maximum 8-hour O3 values, so urban monitors must measure accurately during typically hot, humid, and stagnant O3-conducive day conditions. Conventional photometers reported the highest values for the four highest 8-hour daily maxima during our three month late summer test period, with 8-hour average differences between the new and conventional monitors ranging up to 4 ppb. In paired 10-minute average sampling with a Model 211 in Durham, NC, conventional photometers generally exhibited modest positive interference bias (under 5 ppb) in 176 sampled residences, shops, malls, restaurants, offices, parks, roadways, and vehicles; however, in six percent of our samples indoor differences exceeded 10 ppb and in two 64 ppb and 174 ppb cases exceeded outdoor ambient O3 levels several-fold.

Ollison, W. M.; Capel, J.; Crow, W.; Johnson, T.; Spicer, C. W.

2013-05-01

31

GROWTH OF COTTON UNDER CHRONIC OZONE STRESS AT TWO LEVELS OF SOIL MOISTURE  

Science.gov (United States)

Recent field research has shown that ambient concentrations of ozone(O3) have the potential to reduce yield of a number of economically important crop species. Less emphasis has been placed on characterization of the effects of 03 on growth of the total plant that ultimately dete...

32

Measurement of ambient ozone using a nitrite-coated filter  

Energy Technology Data Exchange (ETDEWEB)

Recently the authors developed a coated filter for ozone collection that they used in a commercially available passive sampling device. Results from the ozone sampler validation tests are presented. The passive ozone sampler used in field and laboratory experiments consists of a badge clip supporting a barrel-shaped body which contains two coated glass fiber filters. The principal component of the coating is nitrite ion, which in the presence of ozone is oxidized to nitrate ion on the filter medium. After sample collection, the filters are extracted with ultrapure water and analyzed for nitrate ion by ion chromatography. The results from laboratory and field validation tests indicate excellent agreement between the passive method and standard ozone monitoring techniques. 22 refs., 6 figs.

Koutrakis, P.; Wolfson, J.M.; Bunyaviroch, A.; Froehlich, S.E.; Hirano, Koichiro; Mulik, J.D. (Harvard School of Public Health, Boston, MA (United States))

1993-02-01

33

Passive sampling of ambient ozone by solid phase microextraction with on-fiber derivatization  

International Nuclear Information System (INIS)

The solid phase microextraction (SPME) device with the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was used as a passive sampler for ambient ozone. Both O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and 1,2-di-(4-pyridyl)ethylene (DPE) were loaded onto the fiber before sampling. The SPME fiber assembly was then inserted into a PTFE tubing as a passive sampler. Known concentrations of ozone around the ambient ground level were generated by a calibrated ozone generator. Laboratory validations of the SPME passive sampler with the direct-reading ozone monitor were performed side-by-side in an exposure chamber at 25 deg. C. After exposures, pyriden-4-aldehyde was formed due to the reaction between DPE and ozone. Further on-fiber derivatizations between pyriden-4-aldehyde and PFBHA were followed and the derivatives, oximes, were then determined by portable gas chromatography with electron capture detector. The experimental sampling rate of the SPME ozone passive sampler was found to be 1.10 x 10-4 cm3 s-1 with detection limit of 58.8 ?g m-3 h-1. Field validations with both SPME device and the direct-reading ozone monitor were also performed. The correlations between the results from both methods were found to be consistent with r = 0.9837. Compared with other methods, the current designed sampler provides a convenient and sensitive tool for the exposure assessments of ozone

2008-03-10

34

40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment ENVIRONMENTAL...SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. P Appendix P to Part 50âInterpretation of the...

2010-07-01

35

Tabulations of ambient ozone data obtained by GASP airliners, March 1975 to December 1977  

Science.gov (United States)

Tabulations are given of GASP ambient ozone mean, standard deviation, median, 84th percentile, and 98th percentile values, by season, flight level, and geographical region. In addition, selected empirical probability variations are highlighted to illustrate the types of curves which might be appropriate in specific analyses of the tabulated data, and an example-case calculation is presented to illustrate how the tables can be used to estimate the frequency of commerical airline flights encountering high cabin ozone levels.

Nastrom, G. D.; Holdeman, J. D.

1980-09-01

36

Use of bioindicators and passive sampling devices to evaluate ambient ozone concentrations in north central Pennsylvania  

International Nuclear Information System (INIS)

Passive samplers and bioindicator plants detect ozone air pollution in north central Pennsylvania. - Ambient concentrations of tropospheric ozone and ozone-induced injury to black cherry (Prunus serotina) and common milkweed (Asclepias syriaca) were determined in north central Pennsylvania from 29 May to 5 September 2000 and from 28 May to 18 September 2001. Ogawa passive ozone samplers were utilized within openings at 15 forested sites of which six were co-located with TECO model 49 continuous ozone monitors. A significant positive correlation was observed between the Ogawa passive samplers and the TECO model 49 continuous ozone monitors for the 2000 (r=0.959) and 2001 (r=0.979) seasons. In addition, a significant positive correlation existed in 2000 and 2001 between ozone concentration and elevation (r=0.720) and (r=0.802), respectively. Classic ozone-induced symptoms were observed on black cherry and common milkweed. In 2000, initial injury was observed in early June, whereas for the 2001 season, initial injury was initially observed in late June. During both seasons, injury was noted at most sites by mid- to late-July. Soil moisture potential was measured for the 2001 season and a significant positive relationship (P<0.001) showed that injury to black cherry was a function of cumulative ozone concentrations and available soil moisture

2003-09-01

37

Colorimetric determination of ambient ozone using indigo blue droplet  

Directory of Open Access Journals (Sweden)

Full Text Available A simple and sensitive method based on a liquid droplet is described for the measurement of atmospheric ozone. A 30 µL drop of indigo blue solution is suspended in a flowing-air sampling stream. The ozone collected reacts with the indigo solution resulting in its decolorization. The colorimetric sensor is composed of two optical fibers and the source of monochromatic light was a red LED (625 nm. The calibration curve was constructed with ozone standard concentrations ranging from 37 - 123 ppbv. The detection limit achieved was 7.3 ppbv. The method considered here showed itself to be easy to apply with a fast response and a total analysis time of only 5 minutes.

Felix Erika P.

2006-01-01

38

Ozone National Ambient Air Quality Standards: Scope and Methods Plan for Welfare Risk and Exposure Assessment.  

Science.gov (United States)

The U.S. Environmental Protection Agency (EPA) is presently conducting a review of the national ambient air quality standards (NAAQS) for ozone. Sections 108 and 109 of the Clean Air Act (Act) govern the establishment and periodic review of the NAAQS. The...

2011-01-01

39

78 FR 44485 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...  

Science.gov (United States)

The EPA is announcing an extension of the public comment period on the Proposed Rule Regarding ``Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements'' (June 6, 2013). The EPA is extending the comment period that originally was scheduled to end on August 5, 2013. The extended comment period will close on September 4, 2013. The EPA is......

2013-07-24

40

Colorimetric determination of ambient ozone using indigo blue droplet  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Um método simples e sensível, baseado em uma gota líquida, é descrito para medida do ozônio atmosférico. Uma gota de 30 µL de solução de índigo azul é suspensa em uma corrente de ar para amostragem. O ozônio coletado reage com a solução de índigo azul, provocando seu descoramento. O sensor colorimét [...] rico é composto por duas fibras ópticas; a fonte de luz monocromática usada foi um LED vermelho (625 nm). A curva analítica foi construída com concentrações padrão de ozônio, na faixa de 37 a 123 ppbv. O limite de detecção alcançado foi 7,3 ppbv. O método considerado mostrou-se de fácil aplicação e resposta rápida, com um tempo total de análise de apenas 5 minutos. Abstract in english A simple and sensitive method based on a liquid droplet is described for the measurement of atmospheric ozone. A 30 µL drop of indigo blue solution is suspended in a flowing-air sampling stream. The ozone collected reacts with the indigo solution resulting in its decolorization. The colorimetric sen [...] sor is composed of two optical fibers and the source of monochromatic light was a red LED (625 nm). The calibration curve was constructed with ozone standard concentrations ranging from 37 - 123 ppbv. The detection limit achieved was 7.3 ppbv. The method considered here showed itself to be easy to apply with a fast response and a total analysis time of only 5 minutes.

Erika P., Felix; Arnaldo A., Cardoso.

 
 
 
 
41

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

Directory of Open Access Journals (Sweden)

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.

Montserrat Fuentes

2010-07-01

42

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

Science.gov (United States)

We assessed the effects of ambient tropospheric ozone on annual tree-ring growth, delta(13)C in the rings, leaf gas exchange and visible injury in three ozone-sensitive woody plant species in southern Switzerland. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air (CF) and non-filtered air (NF) in open-top chambers, and to ambient air (AA) in open plots during the 2001 and 2002 growing seasons. Ambient ozone exposures in the region were sufficient to cause visible foliar injury, early leaf senescence and premature leaf loss in all species. Ozone had significant 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 CO(2) concentrations increased in all species in response to ozone in 2002 only. The width and delta(13)C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Compared with CF seedlings, mean ring width in the AA and NF P. nigra seedlings was reduced by 52 and 46%, respectively, in 2002, whereas in V. lantana and F. excelsior, ring width showed no significant reductions in either year. Although delta(13)C was usually more negative in CF seedlings than in AA and NF seedlings, with the exception of F. excelsior in 2001, ozone effects on delta(13)C were significant only for V. lantana and P. nigra in 2001. Among species, P. nigra exhibited the greatest response to ozone for the measured parameters as well as the most severe foliar injury and was the only species to show a significant reduction in ring width in response to ozone exposure, despite significant negative ozone effects on leaf gas exchange and the development of visible foliar injury in V. lantana and F. excelsior. Thus, significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased delta(13)C in all species, indicating that the timing of ozone exposure and severity of leaf-level responses may be important in determining the sensitivity of tree productivity to ozone exposure. PMID:17403646

Novak, Kristopher; Cherubini, Paolo; Saurer, Matthias; Fuhrer, Jürg; Skelly, John M; Kräuchi, Norbert; Schaub, Marcus

2007-07-01

43

Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation  

International Nuclear Information System (INIS)

In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO3) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO3). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO3 caused, on average, a decrease of 10.2 m3 ha-1 yr-1 in European beech. - Ozone effects on tree growth and stem shape were investigated for Norway spruce and European beech; the study reveals species-specific reaction patterns in growth rate and allometry under ozone exposure.

2010-04-01

44

IJERPH | Free Full-Text | Impact of Climate Change on Ambient Ozone Level and Mortality in Southeastern United States  

...Impact of Climate Change on Ambient Ozone Level and Mortality in Southeastern United States There is a growing interest in quantifying the health impacts ... This paper examines the risks of future ozone levels on non-accidental mortality across 19 urban communities in Southeastern United States. We present ...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 ...

45

Growth parameters and resistance against Drechslera teres of spring barley (Hordeum vulgare L. cv. Scarlett) grown at elevated ozone and carbon dioxide concentrations.  

Science.gov (United States)

Spring barley ( Hordeum vulgare L. cv. Scarlett) was grown at two CO2 levels (400 vs. 700 ppm) combined with two ozone regimes (ambient vs. double ambient) in climate chambers for four weeks, beginning at seedling emergence. Elevated CO2 concentration significantly increased aboveground biomass, root biomass, and tiller number, whereas double ambient ozone significantly decreased these parameters. These ozone-induced reductions in growth parameters were strongly overridden by 700 ppm CO2. The elevated CO2 level increased C : N ratio of the leaf tissue and leaf starch content but decreased leaf protein levels. Exposure to double ambient ozone did not affect protein content and C : N ratio but dramatically increased leaf starch levels at 700 ppm CO2. Resistance against Drechslera teres (Sacc.) Shoemaker was increased in leaves grown at double ambient ozone but was less obvious at 700 ppm than at 400 ppm CO2. Constitutive activities of beta-1,3-glucanase and chitinase were significantly higher in leaves grown at double ambient ozone compared to ambient ozone levels. The sum of methanol-soluble and alkali-released cell wall-bound aromatic metabolites (i.e., C-glycosylflavones and several structurally unidentified metabolites) and lignin contents did not show any treatment-dependent differences. PMID:16388473

Plessl, M; Heller, W; Payer, H-D; Elstner, E F; Habermeyer, J; Heiser, I

2005-11-01

46

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

Science.gov (United States)

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

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

47

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  

Energy Technology Data Exchange (ETDEWEB)

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.

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

48

Effects of ozone and Fusarium root and crown rot on the growth and decline of Alfalfa, Medicago sativa L  

Energy Technology Data Exchange (ETDEWEB)

Research examined the reaction of several major alfalfa cultivars to ozone fumigations in chambers using ozone concentrations simulating ambient levels observed in Massachusetts. These cultivars were all shown to be susceptible in varying degrees to such ozone stress. Further experiments showed that ozone at these concentrations not only reduced growth, but also altered photoassimilate partitioning. Greatest weight reductions occurred in roots, followed by leaves, and then stems. Ozone-stressed plants produced fewer leaves which weighed less per unit area than control leaves. Classic and functional growth analyses were used to examine such parameters as net assimilation rate and relative growth rate. Ozone-stressed plants fixed dry matter less efficiently than control plants, in terms of both leaf area and existing dry matter. In a final study, alfalfa was grown in the presence of isolates of pathogenic Fusarium, or to soil from a diseased alfalfa field, and concurrently fumigated with ozone. There was no significant interaction between pathogen and air pollutant, but each stress significantly reduced alfalfa growth independently.

Cooley, D.R.

1986-01-01

49

On-line monitoring of ambient NMHC Ozone Precursors. The French Experience  

Energy Technology Data Exchange (ETDEWEB)

Non-methane hydrocarbons (NMHC) with up to 10 carbon atom number form the main part of volatile organic compounds (VOC) in urban areas. They play an important role in urban air quality since among these compounds some of them like benzene and 1,3- butadiene are proven carcinogens. Moreover, NMHC play an important role in the photochemical mechanism leading to the formation of excess ozone and other oxidants in the troposphere. This paper presents the French experience in the on-line monitoring of NMHC Ozone Precursors focused on the thirty-one VOC whose concentrations are recommended for measurement in the European directive relating to ozone in ambient air (EC 2002/3/CE directive). Concerning the BTEX compounds and more precisely the benzene which is the only one reglemented compound a brief presentation of the automatic French equipment will be made. Concerning the on-line monitoring, the implementation of automated monitoring systems was made in France step by step from the development of the equipment (on-line sampling with GC-FID analysis of the C2-C9 NMHC priority list) at the 'Ecole des Mines de Douai' (EMD, France) with emphasis on sampling optimisation and calibration method to the field implementation of the automated system at urban locations in northern France with the parallel development of a routine Quality Control (QC) procedure. This work was supported supported by the LCSQA (French Central Laboratory of Air Quality Monitoring). The four-year-successful routine experiences have indicated the suitability of the system for long periods (operating ratio: 88%). Finally, although there is no legal requirements concerning the monitoring of ozone precursors, the on-line measuring equipment was extended to four of the French Air Quality Monitoring Networks in 2001 through a national programme devoted to the monitoring of ozone precursors in ambient air and initiated by the French Ministry of Environment.

Locoge, N. [Departement Chimie et Environnement, Ecole des Mines de Douai, Douai (France)

2004-07-01

50

Tabulations of ambient ozone data obtained by GASP (Global Air Sampling Program) airliners, March 1975 to July 1979  

Science.gov (United States)

Tabulations are given of GASP ambient ozone mean, standard deviation, median, 84th percentile, and 98th percentile values, by month, flight level, and geographical region. These data are tabulated to conform to the temporal and spatial resolution required by FAA Advisory Circular 120-38 (monthly by 2000 ft in altitude by 5 deg in latitude) for climatological data used to show compliance with cabin ozone regulations. In addition seasonal x 10 deg latitude tabulations are included which are directly comparable to and supersede the interim GASP ambient ozone tabulations given in appendix B of FAA-EE-80-43 (NASA TM-81528). Selected probability variations are highlighted to illustrate the spatial and temporal variability of ambient ozone and to compare results from the coarse and fine grid analyses.

Jasperson, W. H.; Holdeman, J. D.

1984-01-01

51

40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

(a) This appendix explains the data handling conventions and computations necessary for determining whether the national 8-hour primary and secondary ambient air quality standards for ozone (O3 ) specified in § 50.15 are met at an ambient O3 air quality monitoring...

2013-07-01

52

A statistical modeling framework for projecting future ambient ozone and its health impact due to climate change  

Science.gov (United States)

The adverse health effects of ambient ozone are well established. Given the high sensitivity of ambient ozone concentrations to meteorological conditions, the impacts of future climate change on ozone concentrations and its associated health effects are of concern. We describe a statistical modeling framework for projecting future ozone levels and its health impacts under a changing climate. This is motivated by the continual effort to evaluate projection uncertainties to inform public health risk assessment. The proposed approach was applied to the 20-county Atlanta metropolitan area using regional climate model (RCM) simulations from the North American Regional Climate Change Assessment Program. Future ozone levels and ozone-related excesses in asthma emergency department (ED) visits were examined for the period 2041-2070. The computationally efficient approach allowed us to consider 8 sets of climate model outputs based on different combinations of 4 RCMs and 4 general circulation models. Compared to the historical period of 1999-2004, we found consistent projections across climate models of an average 11.5% higher ozone levels (range: 4.8%, 16.2%), and an average 8.3% (range: -7%-24%) higher number of ozone exceedance days. Assuming no change in the at-risk population, this corresponds to excess ozone-related ED visits ranging from 267 to 466 visits per year. Health impact projection uncertainty was driven predominantly by uncertainty in the health effect association and climate model variability. Calibrating climate simulations with historical observations reduced differences in projections across climate models.

Chang, Howard H.; Hao, Hua; Sarnat, Stefanie Ebelt

2014-06-01

53

Correlation of ambient inhalable bioaerosols with particulate matter and ozone: A two-year study  

International Nuclear Information System (INIS)

In this study, we have examined the relationships between the concentrations of ambient inhalable airborne fungi and pollen with PM1, PM2.5, ozone, organic carbon, selected trace metals (cadmium, copper, lead, and zinc), temperature, and relative humidity. The database was collected in Cincinnati, Ohio, USA, during two consecutive years. Measurements of all environmental variables were performed at the same site continuously 5 days a week except during winter months. The airborne concentrations of biological and non-biological pollutants ranged as follows: total fungi: 184-16 979 spores m-3; total pollen: 0-6692 pollen m-3; PM1: 6.70-65.38 ?g m-3; PM2.5: 5.04-45.02 ?g m-3; and ozone: 2.54-64.17 ppb. Higher levels of total inhalable fungi and particulate matter were found during fall and summer months. In contrast, total pollen concentration showed elevated levels in spring. Peak concentrations of ozone were observed during summer and beginning of fall. Our study concluded that several types of inhalable airborne fungi and pollen, particulate matter, and ozone could be positively correlated as a result of the atmospheric temperature influence. - Synergistic effects of these pollutants may increase incidence of respiratory health problem

2006-03-01

54

Effects of fluctuating levels of ozone or nitrogen dioxide alone and in sequence on plant growth and photosynthesis  

Energy Technology Data Exchange (ETDEWEB)

Radish plants were exposed daily to ozone or nitrogen dioxide or sequences of the two pollutants. The sequences involved different combinations of exposures. Ozone alone caused no significant effect on growth after 21 days and nitrogen dioxide alone early in the day caused a small growth increase. Increases in quantum yield of chlorophyll fluorescence and in photochemical quenching were observed in both treatments after six days of exposure. This indicated increased photosynthetic assimilation of carbon dioxide. In the case of ozone however, there was no increase in dry matter and it was assumed that the increased assimilation of carbon dioxide was offset by increased maintenance respiration. Exposures to nitrogen dioxide in sequence with ozone resulted in increasingly negative effects on growth. No visible necrotic injury was observed in any treatment. The lack of growth effects due to ozone alone, in contrast to the occurrence of growth effects in nitrogen oxide/ozone sequences indicates that exposures to other pollutants in ambient air must be taken into account in establishing standards of air quality to protect vegetation.

Mazarura, U.

1997-12-31

55

Ambient hydrocarbon and ozone concentrations near a refinery, Benicia, California, 1975. Final report  

Energy Technology Data Exchange (ETDEWEB)

As part of an effort to characterize airborne emissions from petroleum refineries, an ambient air monitoring study was conducted near the Exxon refinery at Benicia, California, during September 8-22, 1975. Ground-level sampling facilities and an airplane equipped with air pollutant monitoring instruments provided an integrated, three dimensional monitoring network. Measurements included ozone, oxides of nitrogen, methane, carbon monoxide, individual C2-C6 hydrocarbons, halocarbons, condensation. Increased concentrations of hydrocarbons, carbon monoxide, condensation nuclei and nitrogen oxides, as well as decreased ozone levels were observed less than five miles from the refinery. At distances greater than 5 miles, elevated condensation nuclei and hydrocarbons were still observed but no discernible differences from background could be detected in NOx, O3, and CO.

Sexton, K.; Westberg, H.

1980-02-01

56

Effects of an ambient level of ozone on primate nasal epithelial mucosubstances. Quantitative histochemistry.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite the absorption of inhaled oxidant gases by the nasal cavity, little effort has been made to characterize the effects of these oxidants on the nasal mucosa. This study defines the effects of ambient concentrations of ozone on the character and amount of mucosubstances in epithelium of nasal mucosa. Bonnet monkeys were exposed to 0.00 or 0.15 ppm O3 (8 hr/day) for 6 or 90 days, anesthetized, and exsanguinated. Nasal cavities were fixed with Karnovsky's fixative, decalcified, and process...

Harkema, J. R.; Plopper, C. G.; Hyde, D. M.; St George, J. A.; Dungworth, D. L.

1987-01-01

57

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 highe...

2012-01-01

58

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

Science.gov (United States)

This appendix explains the data handling conventions and computations necessary for determining whether the national 8-hour primary and secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone air quality monitoring...

2013-07-01

59

Radial diffusive sampler for the determination of 8-h ambient ozone concentrations  

Energy Technology Data Exchange (ETDEWEB)

The 8-h ozone radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers. All the parameters regarding the sampler characteristics were found to be consistent with the requirements of this protocol apart from the blank value, which must be evaluated and subtracted at each sampling. The nominal uptake rate was determined in laboratory conditions. However, the uptake rate depends on the mass uptake, temperature, humidity and on the combination of temperature and humidity. Based on laboratory experiments, an empirical model has been established which improved the agreement between the radial sampler and the reference method. This improvement was observed under several different meteorological and emission conditions of sampling. By using the model equation of uptake rate, the data quality objective of 30% for the expanded uncertainty included in the O{sub 3} European Directive, is easily attained. Therefore, the sampler represents an appropriate indicative method. - A passive sampler has been fully validated for monitoring 8-h ozone concentrations in ambient air.

Plaisance, H. [Laboratoire Central de Surveillance de la Qualite de l' Air - Ecole des Mines de Douai, Departement Chimie et Environnement, 941 rue Charles Bourseul, B.P. 838, 59508 Douai (France); Gerboles, M. [European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, Transport and Air Quality Unit, I-21020 Ispra (Italy)]. E-mail: michel.gerboles@jrc.it; Piechocki, A. [Laboratoire Central de Surveillance de la Qualite de l' Air - Ecole des Mines de Douai, Departement Chimie et Environnement, 941 rue Charles Bourseul, B.P. 838, 59508 Douai (France); Detimmerman, F. [European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, Transport and Air Quality Unit, I-21020 Ispra (Italy); Saeger, E. de [European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, Transport and Air Quality Unit, I-21020 Ispra (Italy)

2007-07-15

60

Radial diffusive sampler for the determination of 8-h ambient ozone concentrations  

International Nuclear Information System (INIS)

The 8-h ozone radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers. All the parameters regarding the sampler characteristics were found to be consistent with the requirements of this protocol apart from the blank value, which must be evaluated and subtracted at each sampling. The nominal uptake rate was determined in laboratory conditions. However, the uptake rate depends on the mass uptake, temperature, humidity and on the combination of temperature and humidity. Based on laboratory experiments, an empirical model has been established which improved the agreement between the radial sampler and the reference method. This improvement was observed under several different meteorological and emission conditions of sampling. By using the model equation of uptake rate, the data quality objective of 30% for the expanded uncertainty included in the O3 European Directive, is easily attained. Therefore, the sampler represents an appropriate indicative method. - A passive sampler has been fully validated for monitoring 8-h ozone concentrations in ambient air

2007-07-01

 
 
 
 
61

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

Directory of Open Access Journals (Sweden)

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.

Hunova I

2012-06-01

62

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone.  

Science.gov (United States)

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought. PMID:16793183

Braun, Sabine; Schindler, Christian; Rihm, Beat; Flückiger, Walter

2007-04-01

63

Relating ambient ozone concentrations to adverse biomass responses of white clover: A case study  

Energy Technology Data Exchange (ETDEWEB)

A white clover model system (consisting of O{sub 3} sensitive, NC-S and tolerant, NC-R clones) offers an opportunity to establish cause (temporally dynamic O{sub 3} exposures) and effect (temporally variable, chronic plant biomass responses) relationships under chamberless, ambient conditions on a regional scale. However, the understanding of the performance of the system (ambient O{sub 3} exposures and the responses of NC-S:NC-R) requires improvement. For example, there are residual carry-over effects in the biomass responses of NC-S:NC-R between successive harvests in a given growth season. However, there were no clear increasing or decreasing trends in these ratios from harvest to harvest during a given growth season. Based on observed differential, perhaps random variations in the biomass responses of NC-S:NC-R, one may conclude that growth regulating factors other than the ambient O{sub 3} were responsible for the observed variability. This is supported by the results of the linear regression analysis between the O{sub 3} exposure potentials (O{sub 3} flux) and the biomass responses of NC-S:NC-R. Future research must include not only site specific measurements of ambient O{sub 3} concentrations and the biomass responses of NC-S and NC-R, but also hourly horizontal windspeeds, air temperature, global radiation and relative humidity to derive more realistic and reliable numerical relationships of cause (O{sub 3} fluxes) and effect (NC-S:NC-R biomass). The resulting predictive models need to be of time series in their nature to account for the stochasticity of the underlying relationships.

Chevone, B. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Plant Pathology, Physiology and Weed Science; Heagle, A. [ARS, Raleigh, NC (United States). Dept. of Plant Pathology; Manning, W. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Microbiology; Varbanov, A.; Krupa, S. [Univ. of Minnesota, St. Paul, MN (United States)

1998-12-31

64

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

Science.gov (United States)

...referred to as area sources. Ozone is predominately...transported to an area from sources in nearby areas or from sources located hundreds...include areas that contribute to nearby violations...Ozone exposure also has been...

2012-05-21

65

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

International Nuclear Information System (INIS)

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)

2013-06-01

66

Characterization of ambient ozone and its precursors around a coking plant.  

Science.gov (United States)

The local-scale relationship between ambient ozone (O3) and its precursors was examined around a coking plant in northern China. The upwind, plant boundary, and downwind locations were selected for investigation during the summer and autumn seasons in 2012. It was found that propene, toluene, and benzene were the top three non-methane hydrocarbon (NMHC) species for O3 formation at plant boundary, while propene, toluene, and m/p-xylene were the top three NMHC species at downwind location. Isoprene was the dominant species for O3 formation at upwind location. It was also found that an O3 depressing process occurred at plant boundary as a result of high NO emissions. Both local photochemistry and transport led to O3 accumulation at the downwind locations. The variation of NMHC concentration during O3 polluted and non-polluted episodes was investigated, and it indicated that NMHC concentration was higher during non-polluted episodes than polluted episodes. The impacts of precursors on O3 formation under different meteorological conditions were also examined. PMID:24504669

Li, Guohao; Cheng, Shuiyuan; Li, Jianbing; Wei, Wei; Wen, Wei; Wang, Gang

2014-05-01

67

Effect of ozone pre-conditioning on quality and antioxidant capacity of papaya fruit during ambient storage.  

Science.gov (United States)

The objective of this study was to compare the physico-chemical characteristics and antioxidant activity of ozone-treated papaya fruit and untreated fruit. Freshly harvested papaya fruit were exposed continuously to ozone fumigation (0, 1.5, 2.5, 3.5 and 5ppm) for 96h prior to ambient storage at 25±3°C and 70±5% relative humidity (RH) for up to 14days. The fruit exposed to 2.5ppm ozone had higher levels of total soluble solids (25.0%), ascorbic acid content (12.4%), ?-carotene content (19.6%), lycopene content (52.1%), and antioxidant activity (30.9%), and also reduced weight loss (11.5%) at day 10 compared to the control. The sensory attributes of papaya treated with 2.5ppm ozone was superior in sweetness and overall acceptability. These results support the application of ozone as a non-thermal and safe food preservation technique for papaya which can benefit both the producers and consumers. PMID:24001808

Ali, Asgar; Ong, Mei Kying; Forney, Charles F

2014-01-01

68

Annual and seasonal trends of ambient ozone concentration and its impact on forest vegetation in Mercantour National Park (South-eastern France) over the 2000-2008 period.  

Science.gov (United States)

In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000-2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor's emissions from Europe have been reduced over the last 20 years. Decreases in annual averages, median, 25th and 98th percentiles and maxima values were found. The seasonal trend analysis for the high-lying stations showed a decreasing trend for the warm season, when main ozone production is the photochemistry, and an increase for the cold period, caused by a reduced ozone titration. Statistics on Arolla Pine reveal strong correlations between mottling intensity and the high ozone concentrations. Finally, decreases for the ozone concentrations, and associated statistics, AOT40 values and for the mottling intensity on conifers needles were observed. PMID:21074915

Sicard, Pierre; Dalstein-Richier, Laurence; Vas, Nicolas

2011-02-01

69

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

International Nuclear Information System (INIS)

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.

2011-06-01

70

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

71

Ozone  

Science.gov (United States)

Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above ... the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed ...

72

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

Science.gov (United States)

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.

Sands, Brian L.; Ganguly, Biswa N.

2013-12-01

73

Annual and seasonal trends of ambient ozone concentration and its impact on forest vegetation in Mercantour National Park (South-eastern France) over the 2000-2008 period  

Energy Technology Data Exchange (ETDEWEB)

In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000-2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor's emissions from Europe have been reduced over the last 20 years. Decreases in annual averages, median, 25th and 98th percentiles and maxima values were found. The seasonal trend analysis for the high-lying stations showed a decreasing trend for the warm season, when main ozone production is the photochemistry, and an increase for the cold period, caused by a reduced ozone titration. Statistics on Arolla Pine reveal strong correlations between mottling intensity and the high ozone concentrations. Finally, decreases for the ozone concentrations, and associated statistics, AOT40 values and for the mottling intensity on conifers needles were observed. - Trends of ambient ozone concentration, associated statistics and specific ozone-induced symptoms on conifers needles were studied in Mercantour National Park (South-eastern France) over the 2000-2008 period.

Sicard, Pierre, E-mail: pierre.sicard@acri-st.f [ACRI-ST, 260 route du Pin Montard, BP 234, 06904 Sophia Antipolis cedex (France); Dalstein-Richier, Laurence [ACRI-ST, 260 route du Pin Montard, BP 234, 06904 Sophia Antipolis cedex (France); Vas, Nicolas [G.I.E.F.S (Groupe International d' Etudes sur les Forets Sud-europeennes), 69 avenue des Hesperides, 06300 Nice (France)

2011-02-15

74

Scientific basis of the national ambient air quality standards for ozone: How do new discoveries and other concerns modify public health risks and expected benefits?  

Energy Technology Data Exchange (ETDEWEB)

The US EPA, in their recent review of the ozone NAAQS, acknowledged that substantial uncertainties exist with respect to the determination of public health risks due to ambient ozone. In particular, the uncertainties focus on considerable differences of opinion among scientists for the possible health effects at ozone levels near the new 8-hr. ozone National Air Quality Standard (NAAQS) of 0.08 ppm. Information on health or vegetation effects of low ambient ozone levels has been scarce, or extrapolated from studies using levels that are substantially above the new standard level. Uncertainties fall into three categories: (1) the extent of the adversity of public health endpoints; (2) the probability of adverse exposures; and (3) the impact of background levels on the achievability of the new standard. More specifically: (A) Public health effects of low ozone levels have thus far depended primarily on compromised pulmonary function as the biological endpoint of the greatest clinical significance. However, research data published after the standard was promulgated show that the ozone-induced effects represent more a physiological defense mechanism than an adverse effect of low ambient ozone concentrations. In light of these new findings, the alleged ozone action represents only a decline in pulmonary function test performance and not in the vital function of the lungs. This new interpretation not only eliminates the adverse character of pulmonary function decrements, but also largely modifies the proposed estimates of public health risks. (B) Public health risk assessments have indicated that even with compliance of the 1-hour ozone standard, the chances for US populations to encounter an adverse ozone exposure have been practically eliminated.

Vostal, J.J.; Heuss, J.M.; Paul, R.T.; Pezda, S.A.; Ball, J.C.; Wimette, H.J.

1999-07-01

75

What Causes Aerosol Growth and Ozone Production in Smoke Plumes?  

Science.gov (United States)

The growth of aerosol particles and production of ozone in smoke plumes is the result of a complex interaction between horizontal diffusion, gas-phase oxidation, coagulation, and mass transfer between phases. Models allow us to separate the effects of these processes and predict their impact on the global environment. We present the results of a new model of gas and aerosol chemistry applied to young biomass burning plumes. The model includes heterogeneous chemistry, kinetic mass transfer, coagulation and the formation of secondary organic and inorganic aerosol. Comparison with measurements from SAFARI 2000 (Hobbs et al., 2003, JGR, doi:10.1029/2002JD002352) suggests the baseline model underpredicts ozone formation and the growth of aerosol within the plume. We explore whether the model predictions can be improved by (1) including heterogeneous HONO production, and (2) adding in surrogates for the uncharacterized organic compounds emitted by the biomass burning. Including the heterogeneous reaction NO2 => HONO greatly improves the match for ozone, OH, and aerosol nitrate concentration, but only when the uptake coefficient approaches 10-3, which is over an order of magnitude higher than previously reported values (Stemmler et al., 2006, doi:10.1038/nature04603). Using the reaction NO2 => 0.5 HONO + 0.5 HNO3 with an uptake coefficient of 10-3 (the top of the range recommended by Jacob, 2000, Atm. Env.,34, 2131-2159) provides an even better match for aerosol nitrate, but produces less O3 and OH than the first reaction. Direct measurements of HONO and OH in young biomass plumes would help determine if this chemistry is taking place. We used two surrogates to model the uncharacterized compounds: long chain alkanes and monoterpenes, representing primary and secondary sources of condensable compounds respectively. Complete condensation of the long-chain alkanes can account for nearly all of the observed increase in organic carbon. However, the accommodation coefficient must be near 10-3 or the alkanes will condense too quickly or too slowly. This value is reasonable when compared to measured accommodation coefficients of organic vapors on organic films (Donaldson et al, 2005, Faraday Discuss, doi:10.1039/b418859d). Monoterpenes gradually increase condensed organic carbon even with accommodation coefficients of 0.1, but produced only 35% as much as the alkanes. Production of sulfate and total particulate matter is below observations in all simulations described above. Better characterization of the composition of the condensed organic matter as a function of downwind distance could help determine the source of the organic aerosol growth.

Alvarado, M. J.; Prinn, R. G.

2006-12-01

76

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone  

Energy Technology Data Exchange (ETDEWEB)

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought. - Epidemiological assessment of shoot growth suggests an ozone sensitivity of mature beech which is similar to seedlings.

Braun, Sabine [Institute for Applied Plant Biology, Sandgrubenstrasse 25, CH-4124 Schoenenbuch (Switzerland)]. E-mail: sabine.braun@iap.ch; Schindler, Christian [Institute for Social and Preventive Medicine, University of Basel, Steinengraben 49, CH-4051 Basel (Switzerland)]. E-mail: christian.schindler@unibas.ch; Rihm, Beat [Meteotest, Fabrikstrasse 14, CH-3012 Berne (Switzerland)]. E-mail: rihm@meteotest.ch; Flueckiger, Walter [Institute for Applied Plant Biology, Sandgrubenstrasse 25, CH-4124 Schoenenbuch (Switzerland)

2007-04-15

77

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone  

International Nuclear Information System (INIS)

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought. - Epidemiological assessment of shoot growth suggests an ozone sensitivity of mature beech which is similar to seedlings

2007-04-01

78

Measurement of ozone in ambient air with microsensors : on-site campaign  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone is actually one of the most important atmospheric pollutants in industrial countries. Measurement is well achieved by continuous monitors but a better information on ozone levels would be given by a denser monitoring network, made possible by using a lighter and cheaper technique like microsensors.Such sensors have been tested successfully in the laboratory. We have therefore undertaken a large on-site campaign, on air quality monitoring stations of the French Networks, to validate the ...

Zdanevitch, Isabelle; Moser, N.; Charpentier, C.; Moquet, A.; Borrel, H.

2004-01-01

79

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

Science.gov (United States)

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...

80

[Effects of elevated ozone on pinus armandii growth: a simulation study with open-top chamber].  

Science.gov (United States)

By using open-top chamber (OTC) and the techniques of dendrochronology, this paper studied the growth of Pinus armandii under elevated ozone, and explored the evolution dynamics and adaptation mechanisms of typical forest ecosystems to ozone enrichment. Elevated ozone inhibited the stem growth of P. armandii significantly, with the annual growth of the stem length and diameter reduced by 35.0% and 12.9%, respectively. The annual growth of tree-ring width and the annual ring cells number decreased by 11.5% and 54.1%, respectively, but no significant change was observed in the diameter of tracheid. At regional scale, the fluctuation of ozone concentration showed significant correlation with the variation of local vegetation growth (NDVI). PMID:24483064

Liu, Chang-Fu; Liu, Chen; He, Xing-Yuan; Ruan, Ya-Nan; Xu, Sheng; Chen, Zhen-Ju; Peng, Jun-Jie; Li, Teng

2013-10-01

 
 
 
 
81

Studies on the biological effects of ozone: 6. Production of transforming growth factor 1 by human blood after ozone treatment.  

Science.gov (United States)

After exposing human whole blood from normal volunteers to ozone concentrations ranging from 22 to 156 micrograms/ml, we have shown that, upon incubation of up to 8 hours, there is a significant release of transforming growth factor beta (TGF-beta 1). In comparison to TGF-beta 1, TGF-beta 2 production is not influenced by ozone concentrations. In line with our previous findings it appears that blood, in the presence of heparin and 5mM Ca,2+ allows a consistent production of tumor necrosis factor a (TNF alpha) and the release of low and non-hazardous levels of free hemoglobin. These data support the contention that autohemotherapy performed after treating blood with ozone followed by reinfusion into the donor, may represent a valuable therapeutic approach for achieving immunoregulatory effects. PMID:7660851

Bocci, V; Luzzi, E; Corradeschi, F; Silvestri, S

1994-01-01

82

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

International Nuclear Information System (INIS)

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.

2010-04-01

83

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

Energy Technology Data Exchange (ETDEWEB)

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 O{sub 3}/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 O{sub 3}/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O{sub 3}/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.

Anderson, J.; Wiseman, S.; Franz, E.; Jones, P.; Liber, K.; Giesy, J. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamal El-Din, M.; Marin, J. [Alberta Univ., Edmonton, AB (Canada)

2010-07-01

84

The impact of ambient ozone on mountain spruce forests in the Czech Republic as indicated by malondialdehyde  

Energy Technology Data Exchange (ETDEWEB)

Malondialdehyde (MDA), a product of lipid peroxidation and biomarker of oxidative stress, is measured over the long term in spruce Picea abies needles under real conditions in three Czech mountain border areas. The trends presented collate the MDA content in spruce needles with ambient ozone, temperature and precipitation as casual, and defoliation as a subsequent factor for the period 1994-2006. We have found the overall decreasing trends in MDA and defoliation. The highest MDA and defoliation are recorded in the Jizerske, the lowest in the Krusne hory Mts. Out of the examined variables the MDA is predicted best by mean temperature in vegetation season, median of O{sub 3} concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O{sub 3} exposure results in higher MDA contents in P. abies needles under real conditions has not been approved. - The assumption that higher ambient O{sub 3} exposure results in higher MDA in Picea abies needles has not been approved in our study under real conditions in three Czech mountain forest areas.

Hunova, Iva, E-mail: hunova@chmi.c [Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4-Komorany (Czech Republic); Novotny, Radek; Uhlirova, Hana [Forestry and Game Management Research Institute, Jiloviste Strnady (Czech Republic); Vrablik, Tomas; Horalek, Jan [Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4-Komorany (Czech Republic); Lomsky, Bohumir; Sramek, Vit [Forestry and Game Management Research Institute, Jiloviste Strnady (Czech Republic)

2010-07-15

85

The impact of ambient ozone on mountain spruce forests in the Czech Republic as indicated by malondialdehyde  

International Nuclear Information System (INIS)

Malondialdehyde (MDA), a product of lipid peroxidation and biomarker of oxidative stress, is measured over the long term in spruce Picea abies needles under real conditions in three Czech mountain border areas. The trends presented collate the MDA content in spruce needles with ambient ozone, temperature and precipitation as casual, and defoliation as a subsequent factor for the period 1994-2006. We have found the overall decreasing trends in MDA and defoliation. The highest MDA and defoliation are recorded in the Jizerske, the lowest in the Krusne hory Mts. Out of the examined variables the MDA is predicted best by mean temperature in vegetation season, median of O3 concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O3 exposure results in higher MDA contents in P. abies needles under real conditions has not been approved. - The assumption that higher ambient O3 exposure results in higher MDA in Picea abies needles has not been approved in our study under real conditions in three Czech mountain forest areas.

2010-07-01

86

A cumulative ozone uptake-response relationship for the growth of Norway spruce saplings  

International Nuclear Information System (INIS)

Norway spruce saplings [Picea abies (L.) Karst.] were exposed during four growing seasons to different ozone treatments in open-top chambers: charcoal filtered air (CF), non-filtered air (NF) and non-filtered air with extra ozone (NF+, 1.4xambient concentrations). The CF and NF+ ozone treatments were combined with phosphorous deficiency and drought stress treatments. The total biomass of the trees was harvested at different intervals during the experimental period. The ozone uptake to current-year needles of the Norway spruce saplings was estimated using a multiplicative stomatal conductance simulation model. There was a highly significant correlation between the reduction of total biomass and the estimated cumulative ozone uptake, which did not vary when different thresholds were applied for the rate of ozone uptake. The reduction of the total biomass was estimated to 1% per 10 mmol m-2 cumulated ozone uptake, on a projected needle area basis. - Growth reductions by Norway spruce saplings correlate with cumulative needle uptake of ozone

2004-02-01

87

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

International Nuclear Information System (INIS)

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

2008-11-01

88

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

89

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  

International Nuclear Information System (INIS)

The effects of foliar applications of ethylenediurea (EDU) on responses to ozone by field-grown bush bean (Phaseolus vulgaris L.) lines 'S156' (O3-sensitive) and 'R123' (O3-tolerant), and cultivars 'BBL 290' (O3-sensitive) and 'BBL 274' (O3-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 O3 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 O3-sensitive and O3-tolerant bush bean plants to EDU applications varied, depending on developmental stages, duration of EDU applications, and fluctuations in ambient O3. - Plant sensitivity to ozone, stage of plant development, number of applications of EDU and ambient ozone affect bean plant responses to EDU

2005-08-01

90

Use of TREGRO to simulate the effects of ozone on the growth of red spruce seedlings  

Energy Technology Data Exchange (ETDEWEB)

TREGRO, a model developed to simulate the growth of sapling red spruce (Picea rubens Sarg.), was parameterized to grow 2- to 3-yr-old seedlings. Results of the simulation compared favorably to actual growth of seedlings used in a field study of the effects of ozone and acidic precipitation on tree physiology and development. Furthermore, a 10-yr simulation produced a modeled tree that corresponded to saplings used in another field experiment. Additional simulations were conducted to compare predicted effects of ozone on seedling growth to those measured in controlled experiments. Based on the performance of the model, we believe TREGRO can be used effectively to simulate both seedling and sapling red spruce growth, and the potential effects of ozone on the development of the trees. 11 refs., 6 figs., 3 tabs.

Laurence, J.A.; Kohut, R.J.; Amundson, R.G. (Boyce Thompson Institute for Plant Research, Ithaca, NY (United States))

1993-08-01

91

Characterization of radicals and high-molecular weight species from alpha-pinene/ozone reaction and ambient aerosol samples  

Science.gov (United States)

Secondary organic aerosol formed during oxidation of different volatile organic compounds is composed from a number of final and intermediate reaction products. The final products include compounds in both low and high molecular weight range called also oligomer species. These compounds can be highly volatile, as well as being semi- or low-volatility compounds. This study characterized intermediate reactive radical products formed from previously often studied alpha-pinene/ozone reaction. In order to passivate those radical species nitrone spin traps were used. 5,5-dimethyl-4,5-dihydro-3H-pyrrole-N-oxide (DMPO), and 5-dietoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) traps were able to successfully trap oxygen- and carbon-centered radicals produced from alpha-pinene/ozone reaction. Electrospray ionization (ESI) in negative ion mode with mass spectrometry (MS) detection was used to scan spectra of formed spin trap adducts and the tandem mass spectrometry (MSn) to elucidate its structures as well as structures of captured radicals. The same method was applied to analyze radical species present in ambient PM2.5 samples. Few carbon- (alkyl) and oxygen- (alkoxyl) centered radicals were captured with DMPO and DEPMPO traps. The second part of this study was focused on high molecular weight (high-MW) species formed from the same reaction (alpha-pinene/ozone), but found also in fine particulate matter fractions of ambient samples. LC/MS/MS analysis of dimer species from chamber study revealed fragments that can originate from peroxide structures. Proposed reaction for these peroxide dimer formation is self reaction of two peroxyl radicals, followed by the loss of oxygen molecule. These findings emphasize the role of peroxyl (ROO) radicals in formation of high-MW products and are in line with the high O:C ratio results reported in other studies. Water soluble organic carbon (WSOC) extracts of three size fractions of the ambient aerosol, PM1--2.5, PM0.1--1, and PMaccounts for the largest WSOC content (from 37% to 47%), while the ultrafine particles in PMcontent (19% to 29%). Spectroscopic measurements (UV-VIS and fluorescence) confirmed structural similarities with aquatic fulvic and hulic acids. However, absorption and emission maxima were shifted to lower wavelengths compared to aquatic standards, indicating the presence of lower MW species and a lower degree of aromaticity. Results showed that the samples collected during September and especially in October had higher MW and higher percentage of aromatic carbon when compared with samples collected during summer months (July/August). Spectroscopy results were confirmed with ESI/MS analysis. That analysis also confirmed presence of four different classes of compounds in ambient aerosols: carboxylic acids, poly-carboxylic acids, organosulfates, and organonitrates.

Pavlovic, Jelica

92

Impact of ozone on the growth of birch (Betula pendula) saplings  

International Nuclear Information System (INIS)

Significant correlation was found between reductions of growth and daylight AOT40 for Betula pendula saplings. - Saplings of one half-sib family of birch, Betula pendula, were exposed to three levels of ozone in open-top chambers (OTCs) during two growing seasons 1997-1998. The ozone treatments were non-filtered air (NF, accumulated daylight AOT40 over the two growing seasons of 3.0 ?l l-1 h), non-filtered air with extra ozone (NF+, accumulated daylight AOT40 of 27.3 ?l l-1 h) and non-filtered air with additional extra ozone (NF++, accumulated daylight AOT40 of 120 ?l l-1 h). The birch saplings, including the roots, were harvested after the first and second growing seasons. After the first growing season, the NF++ treatment reduced the total wood biomass by 22%, relative to the NF treatment. There was no further reduction of the total wood biomass in the NF++ treatment after the second growing season. The root biomass was reduced by 30% after the first growing season. The shoot/root ratio, as well as the proportional biomass of leaves, were increased by ozone during both years. The ozone impact on the relative growth rate was estimated to -2% per 10 ?l l-1 h daylight AOT40 per growing season

2003-08-01

93

Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature  

International Nuclear Information System (INIS)

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO2 sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm-1) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag+, instead of Na+, Ca2+, or K+ ions, existing in the natural clinoptilolite form. The samples Ag/SiO2 and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

2010-12-15

94

Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature.  

Science.gov (United States)

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO(2) sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm(-1)) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag(+), instead of Na(+), Ca(2+), or K(+) ions, existing in the natural clinoptilolite form. The samples Ag/SiO(2) and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature. PMID:20810210

Nikolov, Penko; Genov, Krassimir; Konova, Petya; Milenova, Katya; Batakliev, Todor; Georgiev, Vladimir; Kumar, Narendra; Sarker, Dipak K; Pishev, Dimitar; Rakovsky, Slavcho

2010-12-15

95

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

Energy Technology Data Exchange (ETDEWEB)

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 ({psi}{sub L}) were detected for all three species indicating no differing soil moisture conditions across the sites. Significant variation in stomatal conductance for water vapor (g{sub wv}) was found among species, soil moisture, time of day and sample date. When comparing cumulative ozone uptake and decreased photosynthetic activity (P{sub n}), red maple was the only species to show higher gas exchange under mesic vs. drier soil conditions (P < 0.05). The inconsistent differences in gas exchange response within the same crowns of ash and the uncoupling relationship between g{sub wv} and P{sub n} 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.

Schaub, M. [Graduate Ecology Program, Pennsylvania State University, University Park, PA 16802 (United States); Skelly, J.M. [Department of Plant Pathology, Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: jms34@psu.edu; Zhang, J.W. [Penn State Institutes of the Environment, Pennsylvania State University, University Park, PA 16802 (United States); Ferdinand, J.A. [Penn State Institutes of the Environment, Pennsylvania State University, University Park, PA 16802 (United States); Savage, J.E. [Penn State Institutes of the Environment, Pennsylvania State University, University Park, PA 16802 (United States); Stevenson, R.E. [Department of Plant Pathology, Pennsylvania State University, University Park, PA 16802 (United States); Davis, D.D. [Department of Plant Pathology, Pennsylvania State University, University Park, PA 16802 (United States); Steiner, K.C. [School of Forest Resources, Pennsylvania State University, University Park, PA 16802 (United States)

2005-02-01

96

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

International Nuclear Information System (INIS)

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 (?L) 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

2005-02-01

97

The influence of ultraviolet-B radiation on growth, hydroxycinnamic acids and flavonoids of Deschampsia antarctica during Springtime ozone depletion in Antarctica.  

Science.gov (United States)

We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the growth, biomass production and phenylpropanoid concentrations of Deschampsia antarctica during the springtime ozone depletion season at Palmer Station, along the Antarctic Peninsula. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B either by 83% (reduced UV-B) or by 12% (near-ambient UV-B) over the 63 day experiment (7 November 1998-8 January 1999) when ozone depletion averaged 17%. Plants growing under near-ambient UV-B had 41% and 40% lower relative growth rates and net assimilation rates, respectively, than those under reduced UV-B. The former plants produced 50% less total biomass as a result of having 47% less aboveground biomass. The reduction in aboveground biomass was a result of a 29% lower leaf elongation rate resulting in shorter leaves and 59% less total leaf area in plants grown under reduced UV-B. p-Coumaric, caffeic and ferulic acids were the major hydroxycinnamic acids, and luteolin derivatives were the major flavonoids in both insoluble and soluble leaf extracts. Concentrations of insoluble p-coumaric and caffeic acid and soluble ferulic acids were 38%, 48% and 60% higher, respectively, under near-ambient UV-B than under reduced UV-B. There were no UV-B effects on concentrations of insoluble or soluble flavonoids. PMID:15689180

Ruhland, Christopher T; Xiong, Fusheng S; Clark, W Dennis; Day, Thomas A

2005-01-01

98

75 FR 51960 - Proposed Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard: New...  

Science.gov (United States)

...area's 1-hour ozone NAAQS classification should apply under the anti-backsliding...encryption, and be free of any defects or viruses. For additional...1-hour ozone designation and classification as of the effective date...8-hour ozone designation and classification status. In many...

2010-08-24

99

Development of an ozone high sensitive sensor working at ambient temperature  

Energy Technology Data Exchange (ETDEWEB)

Hybrid SnO{sub 2}/SWNTs thin layer were deposited by using sol-gel process. Such sensitive layers showed very high performances for O{sub 3} flow detection at ambient temperature. Limit sensitivity, lower than 21,5 ppb of O{sub 3} 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 O{sub 3} traces at room temperature. The influence of sensor's working temperature is discussed and finally a reactional mechanism for the detection of O{sub 3} is proposed.

Berger, F; Ghaddab, B; Sanchez, J B; Mavon, C, E-mail: fberger@univ-fcomte.fr [Laboratoire de Chimie-Physique et Rayonnements Alain Chambaudet UMR CEA-E4, UFR ST, La Bouloie, 16 route de Gray, 25030 Besancon Cedex (France)

2011-08-17

100

PHYSIOLOGICAL AND GROWTH RESPONSES OF DIFFERENTIALLY IRRIGATED COTTON TO OZONE (JOURNAL VERSION)  

Science.gov (United States)

The study was conducted to determine the physiological and growth responses of cotton (Gossypium hirsutum L.) to the interaction of ozone (O3) and drought stress. Cotton (cv SJ-2) was grown in open-top chambers in the field at three levels of soil water and exposed to charcoal-fi...

 
 
 
 
101

Bioassaying for ozone with pollen systems  

Energy Technology Data Exchange (ETDEWEB)

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Year-round pollen producion can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.

Feder, W.A.

1981-01-01

102

Reduction of stem growth and site dependency of leaf injury in Massachusetts black cherries exhibiting ozone symptoms  

Energy Technology Data Exchange (ETDEWEB)

Ozone symptomatic trees had a reduced stem growth and symptom expression was enhanced on moister and better growing stands. - Leaf ozone symptoms in natural ecosystems are increasingly reported but ozone effects on tree growth and the mediation of site conditions are still little documented. This study tests two hypotheses: (1) leaf injury in black cherry is associated with decline in radial growth, (2) symptoms are more prevalent on mesic sites. On sites supporting black cherry across Massachusetts, tree growth and leaf ozone injury were surveyed in 1996 using a randomized plot network established in the 1960s. Forty-seven percent of 120 trees sampled for ozone symptoms were symptomatic with generally low levels of injury. Over a 31-year period symptomatic trees had 28% lower stem growth rates than asymptomatic trees. Ozone symptom expression was enhanced in well growing stands on moister, cooler and more elevated sites. Ozone appeared to increase environmental stress and had a more pronounced effect on growth in better growing black cherry stands. This complicates management decisions as thinning increases growth and moisture availability.

Vollenweider, P.; Woodcock, H.; Kelty, M.J.; Hofer, R.-M

2003-10-01

103

Growth response of two varieties of slash-pine seedlings to chronic ozone exposures  

Energy Technology Data Exchange (ETDEWEB)

Two geographical varieties of Pinus elliottii (Engelm.) seedlings, elliottii and densa, were exposed continuously to two daily peak exposure profiles of ozone having 7-h seasonal means of 0.104 and 0.076 ppm and charcoal-filtered air over a 112-day period. The profiles represented a daily rise and decline of hourly ozone concentration. They were constructed with a daily hourly maximum, which for one profile (0.126 micro l/l) exceeded the current ozone standard daily; the standard was not exceeded for the other profile (0.094 micro l/l). Destructive harvests at 7-day intervals over the exposure period were employed to assess visible injury and to construct growth curves for stem diameter, plant height, top and root dry weight, and needle number and length.

Hogsett, W.E.; Plocher, M.; Wildman, V.; Tingey, D.T.; Bennett, J.P.

1985-01-01

104

Combined effects of ozone and water stress on alfalfa growth and yield (journal version)  

Energy Technology Data Exchange (ETDEWEB)

The interactive effects of ozone (O/sub 3/) and water stress on alfalfa were studied to determine how water stress could alter these functions, and to describe the cumulative effects of multiple-year exposures to O/sub 3/ on this perennial crop. Water stress reduced total seasonal yield about 10% in 1984 and 27% in 1985. Ozone significantly reduced yields in both years, and the interaction between O/sub 3/ and water stress was statistically significant in 1985 and for combined 1984 and 1985 years. Ozone dose-alfalfa yield loss functions were homogeneous between 1984 and 1985, and no evidence of a cumulative effect of multiple-year exposure to O/sub 3/ was found on top growth. However, crown (underground stem) weights were significantly reduced by O/sub 3/, suggesting that continued exposure to O/sub 3/ could shorten the productive life of alfalfa stands, in addition to its effect on yield.

Temple, P.J.; Benoit, L.F.; Lennox, R.W.; Reagan, C.A.; Taylor, O.C.

1988-01-01

105

Indirect prediction of surface ozone concentration by plant growth responses in East Asia using mini-open top chambers.  

Science.gov (United States)

We developed small and mobile open top chambers (mini-OTC) measuring 0.6 m (W)?×?0.6 m (D)?×?1.2 m (H) with an air duct of 0.6 m (W)?×?0.23 m (D)?×?1.2 m (H). The air duct can be filled with activated charcoal to blow charcoal filtered air (CF) into the chamber, as opposed to non-filtered ambient air (NF). Ozone sensitive radish Raphanus sativus cv. Red Chime and rosette pakchoi Brassica campestris var. rosularis cv. ATU171 were exposed to NF and CF in mini-OTCs at different locations in East Asia. A total of 29 exposure experiments were conducted at nine locations, Shanghai, China, Ha Noi, Vietnam, Lampang, Phitsanulok and Pathumtani, Thailand, and Hiratsuka, Kisai, Abiko and Akagi, Japan. Although no significant relationships between the mean concentrations of ambient O(3) during the experimental period and the growth responses were observed for either species, multiple linear regression analysis suggested a good relationship between the biomass responses in each species and the O(3) concentration, temperature, and relative humidity. The cumulative daily mean O(3) (ppb/day) could be indirectly predicted by NF/CF based on the dry weight ratio of biomass, mean air temperature, and relative air humidity. PMID:22752963

Kohno, Yoshihisa; Matsumura, Hideyuki; Miwa, Makoto; Yonekura, Tetsushi; Aihara, Keiji; Umponstira, Chanin; Le, Vo Thanh; Ngoc, Nguyen Thuy; Viet, Phanm Hung; Wei, Ma

2013-03-01

106

77 FR 34221 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards for Several...  

Science.gov (United States)

...both the primary and secondary NAAQS for ozone to a...the 0.08 ppm NAAQS set in 1997, but are set at a more protective...respiratory infections, medication use by asthmatics...and lung disease. The secondary ozone standard...

2012-06-11

107

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  

Energy Technology Data Exchange (ETDEWEB)

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.

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

108

Growth and production of buckwheat (Fagopyrum esculentum) treated with reduced, ambient, and enhanced UV-B radiation.  

Science.gov (United States)

The effect of enhanced UV-B radiation on buckwheat (Fagopyrum esculentum Moench. variety 'Darja'), an important high elevation crop, was studied in order to estimate its vulnerability in changing UV-B environment. Plants were grown in outdoor experiments from July to October under reduced and ambient UV-B levels, and an UV-B level simulating 17% ozone depletion in Ljubljana. During the development the following parameters were monitored: light saturated photosynthetic activity, transpiration, potential and effective photochemical efficiencies of photosystem II, the contents of photosynthetic pigments and methanol soluble UV-B absorbing compounds. At the end of the experiment, growth rate and production of seeds were estimated. In the following growth season the seeds collected from plants exposed to different UV-B treatments were tested for germination capacity. Total UV-B absorbing compounds during plant development were increased by UV-B radiation, photosynthetic pigments (chlorophyll a and b and carotenoids) decreased. Photosynthetic rate was lowered in an early stage of development. UV-B treatment resulted in the increase in the transpiration rate and consequently the decrease in water use efficiency (WUE). The disturbances in water economy and in photosynthesis affected the reproduction potential negatively; the production of seeds in plants cultivated under ambient and enhanced UV-B was 57 and 39% of the production of specimens treated with reduced UV-B, respectively. The germination of seeds collected from treated plants revealed on average about 95% success, independently of the treatment, but the time needed for germination was the shortest for seeds developed under enhanced UV-B level treatment. Enhanced UV-B radiation affected water relations and production of buckwheat, but not the potential of seeds for germination. PMID:11849980

Gaberscik, Alenka; Voncina, Meta; Trost, Tadeja; Germ, Mateja; Olof Björn, Lars

2002-02-01

109

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

International Nuclear Information System (INIS)

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

1994-09-07

110

Simultaneous cabin and ambient ozone measurements on two Boeing 747 airplanes. Volume 3: October 1978 - July 1979  

Science.gov (United States)

Measurements of ozone concentrations at cruise altitudes both outside and in the cabin of a Boeing 747SP and Boeing 747-100 airliners in routine commercial service are presented. Plotted and tabulated data are identified by route and are arranged chronologically for each airplane. These data were taken at 5- or 10-min intervals by automated instruments used in the NASA Global Atmospheric Sampling Program (GASP). All GASP cabin ozone data obtained from October 1978 to early July 1979 are presented.

Holdeman, J. D.; Jasperson, W. H.

1985-01-01

111

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

International Nuclear Information System (INIS)

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)

2007-01-01

112

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

International Nuclear Information System (INIS)

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

2011-04-01

113

Growth response of two varieties of slash pine seedlings to chronic ozone exposures  

Energy Technology Data Exchange (ETDEWEB)

Two geographical varieties of Pinus elliottii seedlings, elliottii and densa, were exposed continuously to two daily peak exposure profiles of ozone having 7 h (0900-1600) seasonal means of 0.104 and 0.076 p.p.m. or to charcoal-filtered air over a 112 d period. The profiles represented a daily rise and decline of hourly O/sub 3/ concentration. They were constructed with a daily hourly maxiumm which for one profile (0.126 ..mu..l/litre) exceeded the current O/sub 3/ standard daily; the standard was not exceeded for the other profile (0.094 ..mu..l/litre). Destructive harvests at 7 d intervals, over the exposure period were employed to assess visible injury and to construct growth curves for stem diameter plant height, top and root dry weight and needle number and length. The visible injury was slight, yet all the growth parameters decreased significantly with time and ozone concentration; root growth was the most severely impacted. The observed growth response and visible injury of the two varieties were similar. Seed germination was not affected by O/sub 3/ exposure. 22 references.

Hogsett, W.E.; Plocher, M.; Wildman, V.; Tingey D.T.; Bennett, J.P.

1985-01-01

114

Growth and production of buckwheat (Fagopyrum esculentum) treated with reduced, ambient, and enhanced UV-B radiation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The effect of enhanced UV-B radiation on buckwheat (Fagopyrum esculentum Moench. variety ‘Darja’), an important high elevation crop, was studied in order to estimate its vulnerability in changing UV-B environment. Plants were grown in outdoor experiments from July to October under reduced and ambient UV-B levels, and an UV-B level simulating 17% ozone depletion in Ljubljana. During the development the following parameters were monitored: light saturated photosynthetic activity, transpirat...

Gaberscik, Alenka; Voncina, Meta; Trost, Tadeja; Germ, Mateja; Bjo?rn, Lars Olof

2002-01-01

115

Ozone-induced expression of stress-related genes in arabidopsis thaliana  

Energy Technology Data Exchange (ETDEWEB)

Ozone is a major gaseous pollutant that is known to have detrimental effects on plant growth and metabolism. We have investigated the effects of ozone on Arabidopsis thaliana growth and the pattern of expression of several stress-related genes. A. thalina plants treated with either 150 or 300 parts per billion (ppb) ozone daily for 6 h exhibited reduced growth and leaf curling. Fresh and dry weights of ozone-treated plants were reduced 30 to 48% compared to ambient air controls. RNA blot analyses demonstrated that mRNA levels for glutathione S-transferase (GST), phenylalanine ammonia-lyase (PAL), a neutral peroxidase, and a cytosolic Cu/Zn superoxide dimutase (SOD) were higher in plants treated with 300 ppb ozone than in ambient air-treated controls. The mRNA levels of lipoxygenase and a catalase were not affected by ozone treatment. Of the transcripts examined, GST mRNA levels increased the most, showing a 26-fold induction 3 h after ozone treatment. The neutral peroxidase and SOD mRNA levels rose more slowly, with both reaching maximum levels corresponding to 5-fold and 3-fold induction, respectively, approximately 12 h after ozone treatment. These studies indicate that ozone-induced expression of stress-related genes in A. thaliana provides an excellent model system for investigating the molecular and genetic basis of ozone-induced responses in plants. 54 refs., 6 figs., 2 tabs.

Sharma, Y.K.; Davis, K.R. (Ohio State Univ., Columbus, OH (United States))

1994-08-01

116

Response of giant sequoia canopy foliage to elevated concentrations of atmospheric ozone.  

Science.gov (United States)

We examined the physiological response of foliage in the upper third of the canopy of 125-year-old giant sequoia (Sequoiadendron giganteum Buchholz.) trees to a 61-day exposure to 0.25x, 1x, 2x or 3x ambient ozone concentration. Four branch exposure chambers, one per ozone treatment, were installed on 1-m long secondary branches of each tree at a height of 34 m. No visible symptoms of foliar ozone damage were apparent throughout the 61-day exposure period and none of the ozone treatments affected branch growth. Despite the similarity in ozone concentrations in the branch chambers within a treatment, the trees exhibited different physiological responses to increasing ozone uptake. Differences in diurnal and seasonal patterns of g(s) among the trees led to a 2-fold greater ozone uptake in tree No. 2 compared with trees Nos. 1 and 3. Tree No. 3 had significantly higher CER and g(s) at 0.25x ambient ozone than trees Nos. 1 and 2, and g(s) and CER of tree No. 3 declined with increasing ozone uptake. The y-intercept of the regression for dark respiration versus ozone uptake was significantly lower for tree No. 2 than for trees Nos. 1 and 3. In the 0.25x and 1x ozone treatments, the chlorophyll concentration of current-year foliage of trees Nos. 1 and 2 was significantly higher than that of current-year foliage of tree No. 3. Chlorophyll concentration of current-year foliage on tree No. 1 did not decline with increasing ozone uptake. In all trees, total needle water potential decreased with increasing ozone uptake, but turgor was constant. Although tree No. 2 had the greatest ozone uptake, g(s) was highest and foliar chlorophyll concentration was lowest in tree No. 3 in the 0.25x and 1x ambient atmospheric ozone treatments. PMID:14871711

Grulke, N E; Miller, P R; Scioli, D

1996-06-01

117

Interaction of carbon dioxide and ozone on growth and physiology of C[sub 3] and C[sub 4] species  

Energy Technology Data Exchange (ETDEWEB)

Six native tree and grass species from the forests and prairies of the Midwestern US, differing in stomatal conductance and photosynthetic pathway, were exposed to both ambient and elevated levels of carbon dioxide (CO[sub 2]) and ozone (O[sub 3]). Treatments consisted of all combinations of 350 [mu]L L[sup [minus]1] and 650 [mu]L L[sup [minus]1] CO[sub 2], and < 10 nL L[sup [minus]1] and 100 nL L[sup [minus]1] O[sub 3]. At ambient CO[sub 2], elevated O[sub 3] decreased whole-plant growth in three of the six species after 100 days of exposure. However, this decrease was only significant (P < 0.05) for the C[sub 3] grass species, Agropyron smithii and the tree species Populus tremuloides. Growth losses also occurred for the C[sub 3] grass, Koeleria cristata (P = 0.07) in elevated O[sub 3]. For these three species the deleterious effects of elevated O[sub 3] on whole-plant growth were ameliorated by elevated CO[sub 2]. There were no significant treatment effects on whole-plant growth for the two C[sub 4] grasses, Bouteloua curtipendula, and Schizachyrium scoparium and the tree species Quercus rubra. Photosynthesis measured in high-light for Agrpyron smithii, Koeleria cristata, Populus tremuloides and Schizachyrium scoparium, was reduced significantly (P < 0.05) by elevated O[sub 3] at ambient but not elevated levels of CO[sub 2].

Volin, J.C.; Reich, P.B. (Univ. of Wisconsin, Madison (United States) Univ. of Minnesota, St. Paul (United States))

1993-06-01

118

Ozone Pollution  

Medline Plus

Full Text Available ... Global Access Sci Source. 2007 ; 6: 40. 3 . Medina-Ramón M, Schwartz J. Who is more vulnerable to die from ozone air pollution? Epidemiology. 2008; 19: 672-679. 4 . Thaller EI, Petronell SA, Hochman D, Howard S, Chhikara RS, Brooks EG. Moderate Increases in Ambient PM 2. ...

119

Ozone Pollution  

Medline Plus

Full Text Available ... 2008; 19: 672-679. 4 . Thaller EI, Petronell SA, Hochman D, Howard S, Chhikara RS, Brooks EG. Moderate ... 160-168. Lin S, Liu X, Le LH, Hwang SA. Chronic exposure to ambient ozone and asthma hospital ...

120

An operational assessment of the application of the relative reduction factors in the demonstration of attainment of the 8-hr ozone National Ambient Air Quality Standard.  

Science.gov (United States)

The U.S. Environmental Protection Agency in 1997 revised the 1-hr ozone (O3) National Ambient Air Quality Standard (NAAQS) to one based on an 8-hr average, resulting in potential nonattainment status for substantial portions of the eastern United States. The regulatory process provides for the development of a state implementation plan that includes a demonstration that the projected future O3 concentrations will be at or below the NAAQS based on photochemical modeling and analytical techniques. In this study, four photochemical modeling systems, based on two photochemical models, Community Model for Air Quality and the Comprehensive Air Quality Model with extensions, and two emissions processing models, Sparse Matrix Optimization Kernel for Emissions and Emissions Modeling System, were applied to the eastern United States, with emphasis on the northeastern Ozone Transport Region in terms of their response to oxides of nitrogen and volatile organic carbon-focused controls on the estimated design values. With the 8-hr O3 NAAQS set as a bright-line test, it was found that a given area could be termed as being in or out of attainment of the NAAQS depending upon the modeling system. This suggests the need to provide an estimate of model-to-model uncertainty in the relative reduction factor (RRF) for a better understanding of the uncertainty in projecting the status of an area's attainment. Results indicate that the model-to-model differences considered in this study introduce PMID:15373363

Sistla, G; Hogrefe, C; Hao, W; Ku, J Y; Zalewsky, E; Henry, R F; Civerolo, K

2004-08-01

 
 
 
 
121

No consistent effects of ozone exposure for one growth season on levels of polyamines in Picea abies  

Energy Technology Data Exchange (ETDEWEB)

It is well known that ozone is detrimental to plants, due to its action as a strong oxidant. Polyamines have been suggested as protecting against oxidative stress, and have been reported as being induced by ozone in plants. However, there is a paucity of data on tree species exposed to ozone for an extended period under field-like conditions. In the present investigation, mature spruce clones were exposed to ozone (200 or 400 {mu}g m{sup -3} air) in open-top chambers for an entire growth season at two localities in Norway, and levels of the polyamines putrescine, spermidine and spermine were measured. No consistent effects of ozone fumigation were found on levels of any of the polyamines; not for two clones showing visible injury (yellow needles), and not for four apparently healthy clones. Thus, there was no correlation between sensitivity or tolerance to ozone and polyamine content. However, there were significant differences in polyamine contents between clones and the two localities of exposure 18 refs, 3 figs

Olsen, J.E.; Jensen, E. [Tromsoe Univ. (Norway). Dept. of Plant Physiology and Microbiology

1998-07-01

122

Growth losses in Swiss forests caused by ozone: Epidemiological data analysis of stem increment of Fagus sylvatica L. and Picea abies Karst.  

Science.gov (United States)

The estimate of growth losses by ozone exposure of forest trees is a significant part in current C sequestration calculations and will also be important in future modeling. It is therefore important to know if the relationship between ozone flux and growth reduction of young trees, used to derive a Critical Level for ozone, is also valid for mature trees. Epidemiological analysis of stem increment data from Fagus sylvatica L. and Picea abies Karst. observed in Swiss forest plots was used to test this hypothesis. The results confirm the validity of the flux-response relationship at least for beech and therefore enable estimating forest growth losses by ozone on a country-wide scale. For Switzerland, these estimates amount to 19.5% growth reduction for deciduous forests, 6.6% for coniferous forests and 11.0% for all forested areas based on annual ozone stomatal uptake during the time period 1991-2011. PMID:24911370

Braun, Sabine; Schindler, Christian; Rihm, Beat

2014-09-01

123

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

International Nuclear Information System (INIS)

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O3) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppbv of O3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of ?13C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in ?15N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, ?15N, chlorophyll, leaf area, LMA and biomass occurred at ambient O3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

2005-03-01

124

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  

International Nuclear Information System (INIS)

Twenty-four experiments where EDU was used to protect plants from ozone (O3) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O3-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 (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 O3 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.

2009-05-01

125

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

Science.gov (United States)

In field O(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(3) on the host location of the parasitoid Cotesia plutellae by conducting 24-h trials in an open-air O(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(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(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(3) will not affect the behavior of this parasitoid. PMID:18207294

Pinto, D M; Himanen, S J; Nissinen, A; Nerg, A-M; Holopainen, J K

2008-11-01

126

Ozone decomposition on Ag/SiO{sub 2} and Ag/clinoptilolite catalysts at ambient temperature  

Energy Technology Data Exchange (ETDEWEB)

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO{sub 2} sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm{sup -1}) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag{sup +}, instead of Na{sup +}, Ca{sup 2+}, or K{sup +} ions, existing in the natural clinoptilolite form. The samples Ag/SiO{sub 2} and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

Nikolov, Penko, E-mail: penmail@mail.bg [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Genov, Krassimir; Konova, Petya [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Milenova, Katya; Batakliev, Todor; Georgiev, Vladimir [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Kumar, Narendra [Laboratory of Industrial Chemistry, Process Chemistry Centre, Abo Akademi University, Biskopsgatan 8, 20500 Abo/Turku (Finland); Sarker, Dipak K. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Pishev, Dimitar [University of Chemical Technology and Metallurgy, 1756 Sofia (Bulgaria); Rakovsky, Slavcho [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2010-12-15

127

Intercomparison of ultraviolet photometry and gas-phase titration techniques for ozone reference standards at ambient levels  

Science.gov (United States)

Intercomparison experiments were made between two independent techniques for ozone (O3) reference standards often used as the primary standards in air quality monitoring networks. These techniques include ultraviolet absorption photometry of O3 at the 253.7-nm Hg line and gas-phase titration of O3 with excess NO. For ultraviolet photometry, a well-designed and maintained standard reference photometer (SRP) built by the National Institute of Standards and Technology (USA) was employed. For gas-phase titration (GPT), an existing system was significantly modified by the National Institute for Environmental Studies (Japan) by using gravimetric NO/N2 standard gases, accurate flow measurement systems based on laminar flow elements, and two chemiluminescence NO detectors to minimize uncertainty in the measurements, which had previously been a major shortcoming of this method. Uncertainty in the improved GPT system was reduced to less than 0.4% above 100 nmol mol-1 O3 mole fraction. A series of comparison runs between the two methods over the course of 13 months from August 2004 to August 2005 showed a significant discrepancy, which cannot be explained by the measurement uncertainties attributed to either SRP or GPT in the range of 80-800 nmol mol-1 O3, where GPT was about 2% higher than SRP. This result indicates possible biases in the currently existing O3 reference standards and warrants further studies to identify and characterize possible sources of the systematic discrepancy.

Tanimoto, Hiroshi; Mukai, Hitoshi; Hashimoto, Shigeru; Norris, James E.

2006-08-01

128

A multi-variate statistical model integrating passive sampler and meteorology data to predict the frequency distributions of hourly ambient ozone (O3) concentrations  

International Nuclear Information System (INIS)

A statistical approach is described coupling passive ozone (O3) sampler data with climatological variables to mimic the frequency distributions of hourly ambient O3 concentrations obtained by continuous monitoring. - A multi-variate, non-linear statistical model is described to simulate passive O3 sampler data to mimic the hourly frequency distributions of continuous measurements using climatologic O3 indicators and passive sampler measurements. The main meteorological parameters identified by the model were, air temperature, relative humidity, solar radiation and wind speed, although other parameters were also considered. Together, air temperature, relative humidity and passive sampler data by themselves could explain 62.5-67.5% (R2) of the corresponding variability of the continuously measured O3 data. The final correlation coefficients (r) between the predicted hourly O3 concentrations from the passive sampler data and the true, continuous measurements were 0.819-0.854, with an accuracy of 92-94% for the predictive capability. With the addition of soil moisture data, the model can lead to the first order approximation of atmospheric O3 flux and plant stomatal uptake. Additionally, if such data are coupled to multi-point plant response measurements, meaningful cause-effect relationships can be derived in the future

2003-07-01

129

Foliar response and growth of apple trees following exposure to ozone and sulfur dioxide  

Energy Technology Data Exchange (ETDEWEB)

Three cultivars of greenhouse-grown apple trees (Malus domestica, Borkh.) were fumigated for single, 4-hour exposures with ozone (O/sub 3/) and/or sulfur dioxide (SO/sub 2/) at 0.40 and 0.80 ppm. Fumigations were performed in a plexiglass chamber situated within a controlled environment walk-in growth chamber. All 3 cultivars responded to treatments in a similar manner. When applied separately both gases induced characteristic foliar injury. In general, apple trees were more sensitive to 0.40 ppm O/sub 3/ than to 0.40 ppm SO/sub 2/; but they responded similarly to 0.80 ppm O/sub 3/ or SO/sub 2/. Foliar injury, leaf abscission, and shoot growth reduction were greatest when 0.80 ppm O/sub 3/ and 0.80 ppm SO/sub 2/ were combined. The data showed a less-than additive response when the 2 pollutants were combined; a response due, in part, to the high amount of injury induced by single pollutants at these concentrations. All O/sub 3/ and/or SO/sub 2/ fumigations resulted in stomatal closure.

Shertz, R.D.; Kender, W.J.; Musselman, R.C.

1980-01-01

130

Growth analysis of hybrid poplar cuttings fumigated with ozone and sulphur dioxide  

Energy Technology Data Exchange (ETDEWEB)

To measure the influence of air pollutants on the partitioning of photosynthate into leaves or stems and roots, softwood cuttings of a hybrid poplar clone (Populus deltoides Barr. x P. trichocarpa Torr. and Gray) were fumigated with either zero pollutants, 0-15 ppm ozone (O/sub 3/), 0.25 ppm sulphur dioxide (SO/sub 2/) or 0.15 ppm O/sub 3/ plus O.25 ppm SO/sub 2/ for 12 h a day for 7 weeks. Cuttings were harvested at 3- or 4-day intervals and leaf area and dry weights of leaves, stems and roots were determined. Relative growth rate (K/sub w/), relative leaf area expansion rates (K/sub A/) and relative leaf weight growth rates (K/sub L/) were calculated. Values for K/sub W/ and K/sub L/ were reduced from approximately 0.04 g g/sup -1/ day/sup -1/ for the control cuttings to near zero with the O/sub 3/ plus SO/sub 2/ gas fumigation. K/sub A/ was reduced from 0.04 cm/sup 2/ cm/sup -1/ day /sup -1/ for the control cuttings to zero for the O/sub 3/ plus SO/sub 2/ gas treatment. As K/sub W/ decreased among treatments, K/sub A/ and K/sub L/ decreased by a proportional amount. These results indicate that even though total biomass was reduced by air pollutants, the proportion of total available photosynthate used in leaf growth remained nearly constant.

Jensen, K.F.

1981-12-01

131

Substrate utilization by an oxalate-consuming spirillum species in relation to its growth in ozonated water.  

Science.gov (United States)

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 x 10 CFU/mug of oxalate C and 1.2 x 10 CFU/mug of acetate C were obtained from growth experiments in tap water supplied with various low amounts of either oxalate or acetate. A substrate saturation constant of 0.64 muM oxalate was calculated for strain NOX from the relationship between growth rate and concentration of added oxalate. Maximum colony counts of strain NOX grown in ozonated water (dosages of 2.0 to 3.2 mg of O(3) per liter) were 15 to 20 times larger than the maximum colony counts of strain NOX grown in water before ozonation. Based on the nutritional requirements of strain NOX, it was concluded that carboxylic acids were produced by ozonation. Oxalate concentrations were calculated from the maximum colony counts of strain NOX grown in samples of ozonated water in which a non-oxalate-utilizing strain of Pseudomonas fluorescens had already reached maximum growth. The oxalate concentrations obtained by this procedure ranged from 130 to 220 mug of C/liter. PMID:16346493

van der Kooij, D; Hijnen, W A

1984-03-01

132

Effects of varying environmental conditions on vegetation response to ozone exposure  

Energy Technology Data Exchange (ETDEWEB)

Developing an exposure-effects model for plant response to ozone exposure is a complex process. It is known that ozone must enter the plant through the stomata for an effect to occur. Therefore, ozone uptake is related not only to ambient ozone concentrations, but also to environmental factors which control stomatal movement. In addition, cellular factors within the plant can mitigate ozone impact and ultimately control plant response. This paper presents a review of the scientific literature on plant responses (e.g. visible foliar injury, reductions in growth or yield) to ozone exposures under varying environmental conditions known to affect stomatal aperture. The results of this effort show the importance of considering key environmental factors when developing exposure-effects models.

Zaleski, R.T.; Triemer, L.R.

1995-12-31

133

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

International Nuclear Information System (INIS)

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.

2009-10-01

134

Effects of ozone in ambient air on physiological parameters during senescence of flag leaves of spring wheat. [Triticum aestivum  

Energy Technology Data Exchange (ETDEWEB)

A spring wheat cultivar (Triticum aestivum, cv. Albis) was field-grown near Bern (Switzerland) in open-top chambers or non-chambered plots and exposed to O/sub 3/ daily during the growing period to study effects on physiological parameters associated with senescence of flag leaves. Seasonal 8-hr/d mean O/sub 3/-concentration used were 0.020 (charcoal-filtered, F), 0.035 (non-filtered, NF) and 0.103 ..mu..1/1 (O/sub 3/ added from 9am to 5pm, NF+O/sub 3/) inside, and 0.038 ..mu..1/1 outside the chambers. In leaves exposed to NF+O/sub 3/ chlorophyll loss started 10 d before anthesis and was more rapid than in leaves treated with F or NF. Adaxial and abaxial stomatal conductances were highest in the NF treatment, and about 15% and 80% lower in F and NF+O/sub 3/, respectively. Synthesis of ethylene and 1-aminocyclopropane-1-carboxylic acid (free and conjugated ACC) was stimulated in the F and NF treatment between 10 and 20 d after anthesis. Exposure to NF+O/sub 3/ led to strong inhibition of ethylene and ACC synthesis after anthesis. The results suggest that ambient levels of O/sub 3/ at this site have little effect on these parameters, but that chronic exposure to elevated O/sub 3/ levels is inhibitory to senescence processes of flag leaves, e.g. synthesis of ACC and ethylene.

Grandjean, A.; Fuhrer, J.

1987-08-01

135

Visible injury, crown condition, and growth responses of selected Italian forests in relation to ozone exposure  

International Nuclear Information System (INIS)

The impact of ozone on forest ecosystems in Italy is monitored within the CONECOFOR programme. Ozone levels are measured in 30 plots using passive samplers. Response parameters used are: crown condition (transparency), BAI (basal area increment), and visible symptoms on spontaneous vegetation. Levels of AOT40 are above the concentration-based critical level of 5 ppmh in all sites, but the evidence of impact on forest vegetation remains limited. Ozone is a predictor of crown transparency residuals in beech sites over two consecutive years, but the variance explained amounts to less than 10%. The relation between BAI reduction and ozone is even less certain. Transparency and BAI are more readily explainable in terms of ecological conditions of the site and climate fluctuations. The interpretation of visible symptoms is doubtful, and is conditioned by the prevailing ecological factors in the areas. - Despite considerable exceedance of internationally agreed exposure limits, evidence of ozone effects on selected Italian forest sites is limited.

2009-05-01

136

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

International Nuclear Information System (INIS)

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

2006-11-01

137

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

Science.gov (United States)

Plant functional type (PFT) distributions affect the results of biogenic emission modeling as well as O3 and PM simulations using chemistry-transport models (CTMs). This paper analyzes the variations of both surface biogenic VOC emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. Also, this paper attempts to provide important implications for biogenic emissions modeling studies for CTM simulations. MM5-MEGAN-SMOKE-CMAQ model simulations were implemented over the Seoul Metropolitan Areas in Korea to predict surface O3 concentrations for the period of 1 May to 31 June 2008. Starting from MEGAN biogenic emissions analysis with three different sources of PFT input data, US EPA CMAQ O3 simulation results were evaluated by surface O3 monitoring datasets and further considered on the basis of geospatial and statistical analyses. The three PFT datasets considered were "(1)KORPFT", developed with a region specific vegetation database; (2) CDP, adopted from US NCAR; and (3) MODIS, reclassified from the NASA Terra and Aqua combined land cover products. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BT) are the most significant contributor, followed by needleleaf trees (NT), shrub (SB), and herbaceous plants (HB) to the total biogenic volatile organic compounds (BVOCs). In addition, isoprene from BT and terpene from NT were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. Multiple regression analyses with the different PFT data (?O3 vs. ?PFTs) suggest that KORPFT can provide reasonable information to the framework of MEGAN biogenic emissions modeling and CTM O3 predictions. Analyses of the CMAQ performance statistics suggest that deviations of BT areas can significantly affect CMAQ isoprene and O3 predictions. From further evaluations of the 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.

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

2013-09-01

138

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

DEFF Research Database (Denmark)

The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded into the soil of an open-air experimental field for four growing seasons. The open-air ozone exposure field consists of eight circular plots of which four were fumigated with elevated ozone concentration (doubled ambient) and four were ambient controls. The results showed that E. vaginatum and S. papillosum can tolerate ozone better than expected. Elevated ozone concentration did not affect overall relative length growth of E. vaginatum or S. papillosum. The leaf cross-section area of E. vaginatum leaves was 8% bigger in the ozone treatment compared to that in the ambient control. Ultrastuctural variables did not show any significant treatment effect in E. vaginatum or in S. papillosum. Total chlorophyll (a + b) concentration tended to increase in early growing season under ozone exposure. During the first growing season, elevated ozone concentration decreased methanol-extractable, UV-absorbing compounds in E. vaginatum. The results suggest that E. vaginatum and S. papillosum are ozone tolerant plant species and are likely able to cope with expected increase in tropospheric ozone concentration

Mörsky, SK; Haapala, JK

2011-01-01

139

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

Directory of Open Access Journals (Sweden)

Full Text Available Plant functional type (PFT distributions affect the results of biogenic emission modeling as well as O3 and PM simulations using chemistry-transport models (CTMs. This paper analyzes the variations of both surface biogenic VOC emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. Also, this paper attempts to provide important implications for biogenic emissions modeling studies for CTM simulations. MM5-MEGAN-SMOKE-CMAQ model simulations were implemented over the Seoul Metropolitan Areas in Korea to predict surface O3 concentrations for the period of 1 May to 31 June 2008. Starting from MEGAN biogenic emissions analysis with three different sources of PFT input data, US EPA CMAQ O3 simulation results were evaluated by surface O3 monitoring datasets and further considered on the basis of geospatial and statistical analyses. The three PFT datasets considered were "(1KORPFT", developed with a region specific vegetation database; (2 CDP, adopted from US NCAR; and (3 MODIS, reclassified from the NASA Terra and Aqua combined land cover products. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BT are the most significant contributor, followed by needleleaf trees (NT, shrub (SB, and herbaceous plants (HB to the total biogenic volatile organic compounds (BVOCs. In addition, isoprene from BT and terpene from NT were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. Multiple regression analyses with the different PFT data (?O3 vs. ?PFTs suggest that KORPFT can provide reasonable information to the framework of MEGAN biogenic emissions modeling and CTM O3 predictions. Analyses of the CMAQ performance statistics suggest that deviations of BT areas can significantly affect CMAQ isoprene and O3 predictions. From further evaluations of the 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.

H.-K. Kim

2013-09-01

140

Effects of elevated carbon dioxide, ozone and water availability on spring wheat growth and yield  

Energy Technology Data Exchange (ETDEWEB)

Spring wheat (Triticum aestivum L. cv. Dragon) was exposed to elevated carbon dioxide (CO{sub 2}), alone (1995) or in combination with two levels of increased ozone (O{sub 3}) (1994) or increased irrigation (1996) during three successive growing seasons as part of the EU ESPACE-wheat programme and conducted in open-top chambers (OTCs) and ambient air (AA) plots at Ostad, 50 km north-east of Goeteborg, Sweden. Doubling the CO{sub 2} concentration had a positive effect on grain yield in all 3 years (+21, +7 and +11%, respectively), although only statistically significant in 1994. That year was characterised by a warm and dry summer in comparison with 1995 and 1996, in which the summers were more humid and typical for south-west Sweden. In 1994, the CO{sub 2}-induced increase in grain yield was associated with an increase in the duration of the green leaf area, a positive effect on straw yield and on the number of ears per square metre and a negative effect (-13%) on grain protein concentration. Harvest index was unaffected by the elevated CO{sub 2} concentration. The only statistically significant effect of elevated CO{sub 2} in 1995 was a decrease in the grain protein concentration (-11% in both CO{sub 2} concentrations), and in 1996 an increase (+ 21%) in the straw yield. In 1996 the soil water potential was less negative in elevated CO{sub 2}, which is likely to reflect a lower water consumption of these plants. Addition of extra O{sub 3} significantly affected the grain yield (-6 and -10%, respectively) and the 1000-grain weight negatively (-3 and -6%). Statistically significant interactions between CO{sub 2} and O{sub 3} were obtained for the number of ears per unit area and for the 1000-grain weight. The 1000-grain weight was negatively affected by O{sub 3} in low CO{sub 2}, but remained unaffected in the high CO{sub 2} treatment. There was a significant decrease (- 6%) in the grain protein concentration induced by elevated irrigation. The chambers, compared with AA plots, had a positive effect on plant development and on grain yield in all 3 years. (au)

Pleijel, H.; Danielsson, H.; Karlsson, P.-E.; Skaerby, L. [Swedish Environmental Research Institute (IVL), Goeteborg (Sweden); Gelang, J.; Younis, S.; Wallin, G.; Sellden, G. [Univ. of Goeteborg, Botanical Inst., (Sweden); Sild, E. [Estonian Agricultural Univ., Inst. of Zoology and Botany, Tartu (Estonia)

2000-07-01

 
 
 
 
141

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

Directory of Open Access Journals (Sweden)

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.

Vander Mendonça

2008-04-01

142

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 es [...] quema 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. Abstract in english 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.

Mendonça, Vander; Abreu, Nildo Antônio Arruda de; Souza, Henrique Antunes de; Teixeira, Glauco Antônio; Hafle, Oscar Mariano; Ramos, José Darlan.

143

Ambient air pollutant concentrations during pregnancy and the risk of fetal growth restriction  

Science.gov (United States)

Background Previous studies of air pollution and birth outcomes have not evaluated whether complicated pregnancies might be susceptible to the adverse effects of air pollution. We hypothesized that trimester mean pollutant concentrations would be associated with fetal growth restriction, with larger risks among complicated pregnancies. Methods We used a multiyear linked birth certificate and maternal/newborn hospital discharge dataset of singleton, term births to mothers residing in New Jersey at the time of birth, who were White (non-Hispanic), African American (non-Hispanic), or Hispanic. We defined very small for gestational age (VSGA) as a fetal growth ratio <0.75, small for gestational age (SGA) as ?0.75 and <0.85, and ‘reference’ births as ?0.85. Using polytomous logistic regression, we examined associations between mean pollutant concentrations during the 1st, 2nd, and 3rd trimesters and the risks of SGA/VSGA, as well as effect modification of these associations by several pregnancy complications. Results We found significantly increased risk of SGA associated with 1st and 3rd trimester PM2.5, and increased risk of VSGA associated with 1st, 2nd, and 3rd trimester NO2 concentrations. Pregnancies complicated by placental abruption and premature rupture of the membrane had ~2-5 fold greater excess risks of SGA/VSGA than pregnancies not complicated by these conditions, although these estimates were not statistically significant. Conclusions These findings suggest that ambient air pollution, perhaps specifically traffic emissions during early and late pregnancy and/or factors associated with residence near a roadway during pregnancy, may affect fetal growth. Further, pregnancy complications may increase susceptibility to these effects in late pregnancy.

Rich, David Q.; Demissie, Kitaw; Lu, Shou-En; Kamat, Leena; Wartenberg, Daniel; Rhoads, George G.

2014-01-01

144

Effect of Ozone and Simulated Acid Rain on Growth, Nitrogen Fixation and Peroxidase Activity in Faba Bean (Vicia faba L.) Plant  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Faba beans (Vicia faba L. CV. Giza 400) were exposed to ozone (100 ppb) and simulated acid rain (SAR) at pH 3, separately and combined over 2-weaks period while grown in climate controlled growth chambers. Ozone fumigation (O3) exposure was for 5 h day -1, whereas acid rain exposure was for 2 h per week. The results showed that exposure to high O3 concentration (100 ppb) decreased the number and weight of root nodules, suppressed nitrogenase...

Laila Ezzel-Arab Abdel Nasser

2002-01-01

145

Measurement of Ozone Production Sensor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, ca...

Cazorla, M.; Brune, W. H.

2010-01-01

146

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

International Nuclear Information System (INIS)

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

2008-02-01

147

Effect of ambient temperature in neonate aspic vipers: growth, locomotor performance and defensive behaviors.  

Science.gov (United States)

The impact of temperature during incubation and gestation has been tested in various reptiles; the postnatal period has been rarely investigated however. Three groups of newborn aspic vipers (Vipera aspis) were placed under contrasted thermal regimes during 7 months: (1) a cool 23°C constant regime, (2) a warm 28°C constant regime, and (3) an optimal regime with free-access to a wide range of temperatures. Later, all the snakes were placed under hibernation conditions (6°C) during 3 months. Finally all the snakes were placed in the optimal thermal regime during 2 additional months. The total duration of the experiment was of 12 months. Body mass and feeding rates were recorded weekly, body size was measured monthly. We also assessed locomotor performance and recorded several behavioral traits (e.g., defensive and predatory behaviors). As expected, snakes raised under cool temperatures exhibited low feeding rate, growth rate, body condition, and they exhibited poor locomotor performance; they also displayed marked defensive behaviors (e.g., high number of defensive bites) whilst hesitating during longer periods to bite a prey. Such behavioral effects were detected at the end of the experiment (i.e., 5 months after exposure to contrasted thermal treatments [3 months of hibernation plus 2 months of optimal regime]), revealing long term effects. Surprisingly, growth rate and locomotor performance were not different between the two other groups, warm constant 28°C versus optimal regimes (albeit several behavioral traits differed), suggesting that the access to a wide range of ambient temperatures was not a crucial factor. PMID:23580460

Aïdam, Aurélie; Michel, Catherine Louise; Bonnet, Xavier

2013-07-01

148

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

Energy Technology Data Exchange (ETDEWEB)

Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 {mu}mol mol{sup -1} CO{sub 2}) and two ozone concentrations (ambient and an 8 h day {sup -1} seasonal mean of 50 nmol mol{sup -1} O{sub 3}) 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 O{sub 3} reduced above-ground dry weight at final harvest by 8.4% (P<0.05), but did not affect tuber yields. There was no significant interaction between CO{sub 2} and O{sub 3} for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO{sub 2} 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<0.05) in the 550 {mu}mol mol{sup -1} CO{sub 2} treatment. Responses to 550 and 680 {mu}mol mol{sup -1} CO{sub 2} were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO{sub 2} enrichment. Significant effects on the above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P<0.05) under elevated CO{sub 2}, particularly in the smaller size categories. The results show that the O{sub 3} treatment imposed was insufficient to reduce tuber yields and that, although elevated CO{sub 2} enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. (Author)

Lawson, T.; Craigon, J.; Black, C.R.; Colls, J.J.; Tulloch, A.-M.; Landon, G. [Nottingham Univ., School of Biosciences, Loughborough (United Kingdom)

2001-07-01

149

Ultrastructure and some plasma membrane characteristics of ozone-exposed loblolly pine needles  

Energy Technology Data Exchange (ETDEWEB)

Tropospheric ozone, a phytotoxic air pollutant, causes reduced growth in many tree species. The objective was to determine changes in ultrastructure, the vanadate-sensitive ATPase activity of the plasma membrane, the fatty acids of plasma membrane phospholipids, visible injury, and growth in loblolly pine (Pinus taeda L.) needles exposed to different concentrations of ozone in open-top chambers. The treatments were charcoal filtered air (CF), nonfiltered air (NF), or NF-air with ozone added for 12 h daily at 1.5- or 2-fold ambient ozone concentrations from May to October, 1993. Visible injury was more severe in the high than in the low ozone treatments. Growth of needles of the first flush of 1993 was significantly reduced in the highest ozone treatment. Two types of ultrastructural injury, characterized as either acute of chronic, were observed in mesophyll cells under elevated ozone. The acute injury lead to cell collapse and death. The chronic injury, characterized by decreased chloroplast size and increased density of the stroma, was also found in the NF ozone treatment. Increased density of chloroplast stroma and swelling of thylakoids were transient symptoms, suggesting partial recovery as ozone concentrations decreased in fall. Ozone induced decreases in the specific activity of vanadate-sensitive ATPase of plasmalemma and in the degree of unsaturation in phospholipid fatty acids. The detected reduced needle growth, ultrastructural injury and perturbations in the function and composition of the plasma membrane indicate susceptibility of loblolly pine to ozone. Changes in the plasma membrane phospholipids may have contributed to the decrease in ATPase activity. Injury to the key enzyme of the plasma membrane can directly affect intracellular processes. In the long-term, decreased viability of needles can lead to reductions in loblolly pine productivity. (au) 37 refs.

Anttonen, S. [Univ. of Kuopio, Dept. of Ecology and Environmental Science, Kuopio (Finland); Sutinen, M.L. [The Finnish Forest Research Inst., Rovaniemi Research Station, Rovaniemi (Finland); Heagle, A.S. [North Carolina State Univ., USDA/ARS, Air Quality Research Program, and Dept. of Plant Pathology, Raleigh, NC (United States)

1996-11-01

150

Enhancement of growth, photosynthetic performance and yield by exclusion of ambient UV components in C3 and C4 plants.  

Science.gov (United States)

A field experiment was conducted under tropical climate for assessing the effect of ambient UV-B and UV-A by exclusion of UV components on the growth, photosynthetic performance and yield of C3 (cotton, wheat) and C4 (amaranthus, sorghum) plants. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (utilization of PAR assimilation and enhancement in reducing power in all the four plant species. Exclusion of UV-B in particular significantly enhanced the net photosynthetic rate, stomatal conductance and activity of Rubisco. Additional fixation of carbon due to exclusion of ambient UV-B was channeled towards yield as there was a decrease in the level of UV-B absorbing substances and an increase in soluble proteins in all the four plant species. The magnitude of the promotion in all the parameters studied was higher in dicots (cotton, amaranthus) compared to monocots (wheat, sorghum) after UV exclusion. The results indicated a suppressive action of ambient UV-B on growth and photosynthesis; dicots were more sensitive than monocots in this suppression while no great difference in sensitivity was found between C3 and C4 plants. Experiments indicated the suppressive action of ambient UV on carbon fixation and yield of C3 and C4 plants. Exclusion of solar UV-B will have agricultural benefits in both C3 and C4 plants under tropical climate. PMID:24041852

Kataria, Sunita; Guruprasad, K N; Ahuja, Sumedha; Singh, Bupinder

2013-10-01

151

Ozone and Eusarium: effects on the growth and development of a wilt-susceptible tomato and a wilt-resistant tomato  

Energy Technology Data Exchange (ETDEWEB)

Seedlings of tomato (Lycopersicon esculentum Mill.) cultivars Rutgers (Fusarium-susceptible) and Supersonic (Fusarium-resistant) were transplanted into 20 cm diam. pots of either steamed soil or steamed soil infested with Fusarium oxysporum f. sp. lycopersici (race 1) and grown for 45 days in 2 paired greenhouses. One contained charcoal-filtered air and the other filtered air plus ozone at 0.06-0.08 ppm for 6 hr/day 5 day/week. Slight to moderate white stippling was observed on the older leaves of all plants exposed to ozone. Fusarium wilt symptoms were noted in Rutgers plants grown in filtered air 14-18 days before they were noted in comparable plants exposed to ozone. Symptom expression and death of plants progressed more rapidly in filtered air. Ozone retarded growth and delayed wilt symptoms in Rutgers plants. Supersonic plants did not develop wilt symptoms, but fusarium significantly reduced (P=0.05) root and top dry weights of plants grown in filtered air. Plant height and root and top dry weights for Supersonic plants in Fusarium-infested soil were further significantly (P-0.05) reduced by ozone. Ozone and Fusarium, singly or together in an additive manner, significantly reduced the growth and development of a Fusarium-resistant tomato.

Manning, W.J.; Vardaro, P.M.

1976-01-01

152

Ozone Pollution  

Medline Plus

Full Text Available ... ozone? How Ozone Pollution Harms Your Health Premature death Immediate breathing problems Cardiovascular effects Long-term exposure ... 8 How Ozone Pollution Harms Your Health Premature death . Breathing ozone can shorten your life. Strong evidence ...

153

COMBINED EFFECTS OF OZONE AND WATER STRESS ON ALFALFA GROWTH AND YIELD (JOURNAL VERSION)  

Science.gov (United States)

The interactive effects of ozone (O3) and water stress on alfalfa were studied to determine how water stress could alter these functions, and to describe the cumulative effects of multiple-year exposures to O3 on this perennial crop. Water stress reduced total seasonal yield abou...

154

Measurement of ozone production sensor  

Directory of Open Access Journals (Sweden)

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 residence 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.

M. Cazorla

2009-12-01

155

Influence of low concentrations of ozone on growth, biomass partitioning and leaf senescence in young hybrid poplar plants  

Energy Technology Data Exchange (ETDEWEB)

Chronic exposure to low concentrations of ozone (O3) reduced growth and dry matter accumulation and increased leaf senescence in hybrid poplar Populus deltoides x trichocarpa. Plants were grown in controlled environment chambers and for 10 weeks were exposed daily for 5.5 h to 0.025, 0.050, 0.085 or 0.125 l liter O3. No treatment effects were observed during the first 6 weeks of exposure, except for accelerated leaf senesence in the highest O3 treatment. In contrast, during the final 4 weeks elevated O3 treatments resulted in reduced relative height and diameter growth rates as well as increased leaf senescence. By the end of the study O3 exposure had resulted in decreased plant height and diameter and number of leaves per plant, and in decreased leaf, stem, root and total dry mass per plant. Dry weights of plants in the 0.125 and 0.085 l liter treatments were 10-15% lower than in the 0.025 and 0.050 l liter treatments. Ozone treatments had no effect on partitioning of dry matter. The effects of O3 were linear with respect to treatment concentration.

Reich, P.B.; Lassoie, J.P.

1985-01-01

156

EFFECTS OF SIMULATED ACIDIC RAIN APPLIED ALONE AND IN COMBINATION WITH AMBIENT RAIN ON GROWTH AND YIELD OF FIELD-GROWN SNAP BEAN  

Science.gov (United States)

Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four...

157

Restoration of normoxia by ozone therapy may control neoplastic growth: a review and a working hypothesis.  

Science.gov (United States)

In contrast to normal tissues, tumors thrive in hypoxic environments. This appears to be because they can metastasize and secrete angiopoietins for enhancing neoangiogenesis and further tumor spread. Thus, during chronic ischemia, normal tissues tend to die, while neoplasms tend to grow. During the past two decades, it has been shown in arteriopathic patients that ozonated autohemotherapy is therapeutically useful because it increases oxygen delivery in hypoxic tissues, leading to normoxia. Although several oxygenation approaches have been tested, none is able to restore normoxia permanently in patients with cancer. We postulate that a prolonged cycle of ozonated autohemotherapy may correct tumor hypoxia, lead to less aggressive tumor behavior, and represent a valid adjuvant during or after chemo- or radiotherapy. Moreover, it may re-equilibrate the chronic oxidative stress and reduce fatigue. PMID:15865491

Bocci, Velio; Larini, Alessandra; Micheli, Vanna

2005-04-01

158

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

International Nuclear Information System (INIS)

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

2008-04-30

159

Final report of the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with NMC, A*STAR, May 2013  

Science.gov (United States)

As part of the on-going key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Singapore maintained by the National Metrology Centre, A*STAR (NMC, A*STAR) 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).

Viallon, Joële; Moussay, Philippe; Wielgosz, Robert; Li, Hou; Hui, Wendy Liu; Norris, James E.; Guenther, Frank

2014-01-01

160

Final report of the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with NPL (May 2013)  

Science.gov (United States)

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of the United Kingdom maintained by the National Physical Laboratory (NPL) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). 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).

Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Sweeney, Bryan; Quincey, Paul

2014-01-01

 
 
 
 
161

Final report of the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with JRC (October 2013)  

Science.gov (United States)

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of the European Commission maintained by the Joint Research Centre (JRC) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). 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).

Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Lagler, Friedrich

2014-01-01

162

Final report of the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with NIST (February 2013)  

Science.gov (United States)

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the National Institute of Standards and Technology (NIST) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). 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).

Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Norris, James E.; Guenther, Franck

2014-01-01

163

Radial diffusive samplers for determination of 8-h concentration of BTEX, acetone, ethanol and ozone in ambient air during a sea breeze event  

Science.gov (United States)

The radial diffusive sampler Radiello ® filled with Carbograph 4 was evaluated for monitoring BTEX, ethanol and acetone concentrations for 8-hour exposure time. The sampling rates were first evaluated in an exposure chamber under standard conditions. Benzene and toluene showed the highest sampling rates with satisfactory standard deviations. Ethylbenzene and xylenes showed medium sampling rates but higher standard deviations that can be attributed to a low affinity of these compounds with the adsorbent medium for short sampling time. Acetone has a fair result because of the increase of its partial pressure in the vicinity of the adsorbent surface in the course of sampling. The Carbograph 4 adsorbent does not seem to be suitable for sampling ethanol, likely because of its high volatility. The influences of three environmental factors (temperature (T), relative humidity (RH) and concentration level (C)) on the sampling rates were also evaluated, following a fractional factorial design at two factor levels (low and high). Results were only investigated on benzene, toluene and acetone. Temperature and relative humidity are found to be the most important factors leading to variability of the benzene and toluene sampling rates. The applicability of the sampler for 8-hour sampling was demonstrated by the results of a measurement campaign carried out during a sea breeze event. Mapping of benzene, toluene and acetone concentrations showed the highest concentrations in the industrial zone following the wind direction coming from the North. Nevertheless, the sea breeze tends to reduce the spread of the industrial plumes. On the contrary, the ozone map presents the lowest concentrations at the same industrial area indicating a net consumption of ozone. The highest ozone concentrations were found in the southeastern zone suggesting a local ozone formation.

Roukos, Joelle; Locoge, Nadine; Sacco, Paolo; Plaisance, Hervé

2011-01-01

164

Relative effects of elevated background ozone concentrations and peak episodes on senescence and above-ground growth in four populations of Anthoxanthum odoratum L  

International Nuclear Information System (INIS)

Four populations of Anthoxanthum odoratum from North Wales, UK, were exposed to the following combinations of mean background and peak concentrations of ozone for 12 weeks in solardomes: LL (14.3 ppb, 18.9 ppb, respectively), LH (14.8 ppb, 52.3 ppb), HL (28.9 ppb, 35.7 ppb) and HH (30.5 ppb, 72.1 ppb). Elevated ozone rapidly induced premature senescence, with effect increasing in the order: LL 12 values (accumulated between 8am and 8pm) were very different at 10.6 ppm h and 4.1 ppm h, respectively. Overall, linear correlations between whole plant senescence were stronger for AOT0 than for AOT40. Intraspecific variation in the senescence response to the different profiles was observed after 11 weeks of exposure. Effects on growth and tillering were less pronounced than effects on senescence. - Elevated background ozone concentrations induce premature senescence to a greater extent than peak episodes

2009-02-01

165

Ozone Pollution  

Medline Plus

Full Text Available Home > 2013 > Health Risks > Ozone Pollution Health Risks Ozone Pollution Particle Pollution Focusing on Children Disparities Protect Yourself Infographic ... the current research on ozone pollution in February 2013. 23 The EPA had engaged a panel of ...

166

Ozone Pollution  

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Full Text Available ... higher ozone readings and more frequent high ozone days. Sunlight and heat create conditions that increase the ... Fortunately, these cities had significantly fewer unhealthy ozone days than they had a decade ago thanks to ...

167

Ozone Pollution  

Medline Plus

Full Text Available ... come in contact with sunlight, they react and form ozone smog. The essential raw ingredients for ozone ... present under the right conditions, they react to form ozone. And because the reaction takes place in ...

168

Ozone Pollution  

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Full Text Available ... Ozone Come From? Who is at risk from breathing ozone? How Ozone Pollution Harms Your Health Premature death Immediate breathing problems Cardiovascular effects Long-term exposure risks EPA ...

169

Ozone Pollution  

Medline Plus

Full Text Available ... Health Risks > Ozone Pollution Health Risks Ozone Pollution Particle Pollution Focusing on Children Disparities Protect Yourself Infographic ... BP. Association of Low-Level Ozone and Fine Particles with Respiratory Symptoms in Children with Asthma. JAMA . ...

170

Ozone Pollution  

Medline Plus

Full Text Available ... contributed to higher ozone readings and more frequent high ozone days. Sunlight and heat create conditions that increase the risk of high ozone levels. Fortunately, these cities had significantly fewer ...

171

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

Science.gov (United States)

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.

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

2014-04-01

172

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

Directory of Open Access Journals (Sweden)

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.

S. Chatani

2014-04-01

173

Effects of low levels of ozone and sulfur dioxide on growth and physiology of hybrid poplar and soybean  

Energy Technology Data Exchange (ETDEWEB)

Laboratory and field tests were conducted to assess the effects of low levels (< 0.15 ..mu..l l/sup -1/) of O/sub 3/ and/or SO/sub 2/ on plant growth and physiology. A new technique was used to expose unenclosed soybean (Glycine max cv Hark) and hybrid poplar (Populus deltoides x trichocarpa) plants in the field with low levels of these two pollutants. Results of field studies indicated that: there were no significant interactions between the pollutants; exposure to low concentrations of either pollutant had negative, linear effects on plant growth and productivity; O/sub 3/ was approximately three times as phytotoxic as SO/sub 2/ on a concentration or dosage basis; and plant growth and productivity were significantly affected by levels of O/sub 3/ which are frequently found in ambient air, while effects of ambient levels of SO/sub 2/ were minimal. Results of these studies suggest that vegetation growing in areas that experience elevated O/sub 3/ levels probably suffer deleterious effects of such exposure. Low level O/sub 3/ pollution is widespread and therefore, this scenario has potentially far-reaching implications. In contrast, the lesser effects of low levels of SO/sub 2/ suggests that concern over this pollutant should be largely directed at sensitive species, areas of high concentrations, potential interactions, and/or as a contributing factor to acid precipitation.

Reich, P.B.

1983-01-01

174

Quantitative constraints on the 17O-excess (?17O) signature of surface ozone: Ambient measurements from 50°N to 50°S using the nitrite-coated filter technique  

Science.gov (United States)

The unique and distinctive 17O-excess (?17O) of ozone (O3) provides a conservative tracer for oxidative processes in both modern and paleo-atmospheres and has acted as the primary driver of theoretical and experimental research into non-mass-dependent fractionation (NMDF) for over three decades. However, due to the inherent complexity of extracting O3 from ambient air, the existing observational dataset for tropospheric O3 isotopic composition remains quite small. Recent analytical developments have provided a robust and reliable means for determining ?17O(O3)trans., the transferrable ?17O signature of ozone in the troposphere (Vicars et al., 2012). We have employed this new methodology in a systematic investigation of the spatial and seasonal features of ?17O(O3)trans. in two separate field campaigns: a weekly sampling effort at our laboratory in Grenoble, France (45°N) throughout 2012 (n = 47) and a four-week campaign onboard the Research Vessel (R/V) Polarstern along a latitudinal transect from 50°S to 50°N in the Atlantic Ocean (n = 30). The bulk 17O-excess of ozone, denoted ?17O(O3)bulk, exhibited mean (±1?) values of 26.2 ± 1.3‰ (?17O(O3)trans. = 39.3 ± 2.0‰) and 25.9 ± 1.1‰ (?17O(O3)trans. = 38.8 ± 1.6‰) for the Grenoble and R/V Polarstern collections, respectively. This range of values is in excellent quantitative agreement with the two previous studies of ozone triple-isotope composition, which have yielded mean (±1?) ?17O(O3)bulk values of 25.4 ± 9.0‰ (n = 89). However, the magnitude of variability detected in the present study is much smaller than that formerly reported. In fact, the standard deviation of ?17O(O3)bulk in each new dataset is lower than the uncertainty previously estimated for the filter technique (±1.7‰), indicating a low level of natural spatial and temporal variation in the 17O-excess of surface ozone. For instance, no clear temporal pattern in ?17O(O3) is evident in the annual record from Grenoble despite dramatic seasonal variations in ozone and atmospheric reactive nitrogen (NOx = NO + NO2) concentrations. However, a small but statistically significant difference is distinguishable in the R/V Polarstern record when comparing samples collected in the Southern and Northern Hemispheres, which possessed average ?17O(O3)bulk values of 25.2 ± 1.0‰ and 26.5 ± 0.7‰, respectively. The implications of these results are discussed in the context of the tropospheric ozone budget and the use of oxygen isotope ratios of secondary atmospheric species to derive information regarding oxidation pathways from modern and paleo-atmospheres.

Vicars, William C.; Savarino, Joël

2014-06-01

175

Effects of ozone exposures on epicuticular wax of ponderosa pine needles  

International Nuclear Information System (INIS)

Two-year-old ponderosa pine (Pinus ponderosa L.) seedlings were exposed during the 1989 and 1990 growing seasons to ozone in open-top chambers placed in a forested location at Shirley Meadow, Greenhorn Mountain Range, Sierra Nevada. The ozone treatments were as follows: charcoal-filtered air (CF); charcoal-filtered air with addition of ambient concentrations of ozone (CF + O_3); and charcoal-filtered air with addition of doubled concentrations of ozone (CF + 2 x O_3). Ozone effects on ponderosa pine seedlings progressed and accumulated over two seasons of exposure. Throughout the first season, increased visible injury and accelerated senescence of the foliage were noted. Subsequently, during the second season of ozone exposure, various physiological and biochemical changes in the foliage took place. All these changes led to reduced growth and biomass of the seedlings. Epistomatal waxes of needles from the CA + 2 x O_3 treatment had an occluded appearance. This phenomenon may be caused by earlier phenological development of needles from the high-ozone treatments and disturbed development and synthesis of waxes. It may also be caused by chemical degradation of waxes by exposures to high ozone concentrations. (orig.)

1994-01-01

176

Biogenic Growth of Alloys and Core-Shell Nanostructures Using Urease as a Nanoreactor at Ambient Conditions  

Science.gov (United States)

Biomineralization is an extremely efficient biologically guided process towards the advancement of nano-bio integrated materials. As a prime module of the natural world, enzymes are expected to play a major role in biogenic growth of inorganic nanostructures. Although there have been developments in designing enzyme-responsive nanoparticle systems or generation of inorganic nanostructures in an enzyme-stimulated environment, reports regarding action of enzymes as reducing agents themselves for the growth of inorganic nanoparticles still remains elusive. Here we present a mechanistic investigation towards the synthesis of metal and metallic alloy nanoparticles using a commonly investigated enzyme, Jack bean urease (JBU), as a reducing as well as stabilizing agent under physiological conditions. The catalytic functionality of urease was taken advantage of towards the development of metal-ZnO core-shell nanocomposites, making urease an ideal bionanoreactor for synthesizing higher order nanostructures such as alloys and core- shell under ambient conditions.

Sharma, Bhagwati; Mandani, Sonam; Sarma, Tridib K.

2013-01-01

177

Exposure-Relevant Ozone Chemistry in Occupied Spaces  

Energy Technology Data Exchange (ETDEWEB)

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 byproduct yield) were explored. In Chapter 5, the reaction of ozone with permethrin, a residual insecticide used in aircraft cabins, to form phosgene is investigated. A derivatization technique was developed to detect phosgene at low levels, and chamber experiments were conducted with permethrin-coated cabin materials. It was determined that phosgene formation, if it occurs in the aircraft cabin, is not likely to exceed the relevant, health-based phosgene exposure guidelines.

Coleman, Beverly Kaye

2009-04-01

178

Ozone Watch  

Science.gov (United States)

This is the Ozone Hole Watch web site, where you can check on the latest status of the ozone layer over the South Pole. Satellite instruments monitor the ozone layer, and their data is used to create the images that depict the amount of ozone. The web site also contains links for classroom activities and instructional materials.

National Aeronautics and Space Administration (NASA)

179

EFFECTS OF CARBON DIOXIDE AND OZONE ON GROWTH AND BIOMASS ALLOCATION IN PINUS PONDEROSA  

Science.gov (United States)

The future productivity of forests will be affected by combinations of elevated atmospheric CO2 and O3. Because productivity of forests will, in part, be determined by growth of young trees, we evaluated shoot growth and biomass responses of Pinus ponderosa seedlings exposed to ...

180

Long-term prediction of fish growth under varying ambient temperature using a multiscale dynamic model  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Feed composition has a large impact on the growth of animals, particularly marine fish. We have developed a quantitative dynamic model that can predict the growth and body composition of marine fish for a given feed composition over a timespan of several months. The model takes into consideration the effects of environmental factors, particularly temperature, on growth, and it incorporates detailed kinetics describing the main metabolic processes (protein, lipid, and central metabolism known to play major roles in growth and body composition. Results For validation, we compared our model's predictions with the results of several experimental studies. We showed that the model gives reliable predictions of growth, nutrient utilization (including amino acid retention, and body composition over a timespan of several months, longer than most of the previously developed predictive models. Conclusion We demonstrate that, despite the difficulties involved, multiscale models in biology can yield reasonable and useful results. The model predictions are reliable over several timescales and in the presence of strong temperature fluctuations, which are crucial factors for modeling marine organism growth. The model provides important improvements over existing models.

Radde Nicole

2009-11-01

 
 
 
 
181

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone  

Energy Technology Data Exchange (ETDEWEB)

Radish and marigold plants were exposed to 0.3 ppM of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and /or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/ and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 2/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present. 8 references, 2 tables.

Reinert, R.A.; Sanders, J.S.

1982-02-01

182

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone  

Energy Technology Data Exchange (ETDEWEB)

Radish and marigold plants were exposed to 0.3 ppm of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and/or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 3/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present.

Reinert, R.A.; Sanders, J.S.

1982-02-01

183

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

International Nuclear Information System (INIS)

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)

2010-01-01

184

The 2003 Antarctic Ozone Hole  

Science.gov (United States)

TOMS provides dramatic visual evidence of the annual growth and decay of the Antarctic ozone hole. The ozone losses over Antarctica result from reactions with the products of man-made chlorine and bromine compounds. Because of the tilt of the Earths axis, continuous darkness falls at the South Pole from March 21 to September 21. The dark region in the middle of the July 1 total ozone picture is polar night, where TOMS cannot make measurements. Ozone losses are in blue. Beginning in August, returning sunlight reaches the edges of Antarctica providing chlorine and bromine compounds with energy to rapidly destroy ozone. By mid September, the ozone loss peaks, creating an ozone hole over Antarctic. For more information see www.gsfc.nasa.gov-topstory-2003-1208toms.html

Shirah, Greg; Newman, Paul

2004-09-07

185

Measurement of survace ozone over New Dehli  

Science.gov (United States)

The measurement of surface ozone concentration is important for understanding and predicting photo chemical air pollution in u ban areas. In the troposphere ozone is ar green house gas trapping the long wave length radiation in 9.6 ?m band. Surface ozone is a secondary pollutant its concentration in lower troposphere depends upon its precursors (CO, CH4, Non methane hydrocarbons, NO ) as well as weather and transport phenomenon. Ozone is a oxidizing agent increasing concentration of which can modulate the oxidizing efficiency of troposphere and may have significant consequences for the chemistry of atmosphere and climate. The regular information of its ground level concentrations is needed for setting ambient air quality objectives and understanding air pollution effects on human and vegetation health also. The measurements of surface ozone is being carried out in National Physical laboratory since 1997. The measurements showed that on a number of days the surface ozone values exceeds WHO ambient ozone air quality standards in summer season as well as in the months of October and November. In the annual variation of surface ozone two maxima (April and October) and two minima ( December and monsoon months) were observed . The increase of night time ozone concentrations has been observed predominantly in winter season. This may be correlated due to mixing of the remnant day time boundary layer ozone by mechanical turbulence produced by wind shear. The high nocturnal ozone has also been observed during thunderstorms. In the present paper observations and results obtained will be described.

Arya, B.; Jain, S.; Kumar, A.

186

Evaluation of the anti-oxidant ethylene diurea (EDU) as a protectant against ozone effects on crops (Growth chamber trials)  

Energy Technology Data Exchange (ETDEWEB)

A field study conducted during the summer of 2000 showed that when the antioxidant ethylene diurea (EDU) was applied to crops there was an increase in several parameters. The authors designed a series of controlled-environment trials to test the following: were the effects of EDU the result of EDU-mediated protection against ozone (O{sub 3}) or were they from the plant growth promoting effects of EDU independent of O{sub 3}. The three major objectives were: (1) to modify an existing gas exposure system to expose plants to O{sub 3} and to test the stability and reliability of the system, (2) to perform O{sub 3} exposure trials using wheat, barley, field pea and canola to observe the effects of O{sub 3}, and (3) to test whether the effects of EDU could be attributed to protection against O{sub 3} injury or to the plant growth promoting effects independent of O{sub 3}. The modification to the gas exposure system involved the installation of an O{sub 3} delivery system and a monitoring system. Stability of the system was tested using radish plants. The symptoms of O{sub 3} injury on radish leaves began after two weeks of exposure. It appeared as mottled bleached areas which became red. Mottled chlorotic areas appeared on wheat and barley, which led to complete chlorosis, necrosis and eventually abscission. After two weeks of exposure, field pea developed tendril curl, and canola plants displayed no visible signs of injury from O{sub 3} exposure. The results of the study indicated that the effects of EDU can be species- and cultivar-specific. 15 refs., 11 tabs., 8 figs.

Archambault, D.J.; Li, X. [Alberta Research Council, Vegreville, AB (Canada). Environmental Technologies

2003-02-01

187

Effects of ozone on the growth of radish plants at different temperatures  

Energy Technology Data Exchange (ETDEWEB)

The temperature in a natural-light .Phitetron was set to 20/sup 0/C/ 13/sup 0/C, 25/sup 0/C/18/sup 0/C, and 30/sup 0/C/23/sup 0/C (daytime/nighttime), and the specimen plant was exposed to 0.1-ppm O/sub 3/ for four hours a day during the period of seven days. Thereafter, the leaf area was measured, and the dry weight of each plant organ was measured fro growth analysis. The dry growth per individual plant was reduced by 20% or more at 25/18/sup 0/C and 30/23/sup 0/C. The results of analysis suggests that the growth reduction is attributable to a reduction in net assimilation rate. At 20/13/sup 0/C, the influence of O/sub 3/ was not observed. The influence on net photosynthetic rate was studied from values of gas exchange measurement on the leaf. It has been revealed that the photosynthetic rate reduction caused by exposure to O/sub 3/ is 10% at 25/18/sup 0/C and 13% at 30/23/sup 0/C and is nearly negligible at 20/13/sup 0/C. Low growth under high temperature seems due to the fact that O/sub 3/ hinders net photosynthesis. (1 fig, 4 tabs, 21 refs)

Izuta, Takeshi; Funada, Shu; Ohashi, Takeshi; Miyake, Hiroshi; Totsuka, Tsumugu

1988-08-20

188

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  

Energy Technology Data Exchange (ETDEWEB)

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.

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

189

Intraspecific variations in growth, yield and photosynthesis of sorghum varieties to ambient UV (280-400 nm) radiation.  

Science.gov (United States)

A field study was conducted to investigate the impact of ambient solar UV on the various growth, physiological and yield parameters of four sorghum (Sorghum bicolor L.) varieties-Indore-12, Indore-26, CSV-23 and Indore-27 by excluding either UV-B (leaf weight of flag leaf, biomass accumulation, yield parameters and harvest index in all the sorghum varieties. Chlorophyll b was significantly enhanced and chlorophyll a increased to a lesser extent, UV-B absorbing substances and chlorophyll a/b ratio were significantly decreased by the exclusion of solar UV. The enhancement in the vegetative growth and yield by UV exclusion might be linked to the remarkable increase in rate of photosynthesis in sorghum varieties. The magnitude of the response was high in I-26 and I-27 as compared to CSV-23 and I-12 after exclusion of solar UV. All the varieties of sorghum had a negative cumulative stress response index (CSRI), the sensitivity of the sorghum varieties was in the following sequence I-12>CSV-23>I-26>I-27. Thus I-27 was the most sensitive and I-12 the least sensitive variety to present level of solar UV radiation. The differences in UV sensitivity identified among sorghum varieties might be useful in breeding programs for increased tolerance to UV-B radiation. PMID:23017902

Kataria, Sunita; Guruprasad, K N

2012-11-01

190

On the influence of the ambient environment on the fatigue crack growth process in steels  

International Nuclear Information System (INIS)

A comparison of the crack opening and fatigue crack growth characteristics of three tempered martensitic steels; a modified 4135, 2 1/4Cr 1Mo and a modified 9Cr 1Mo; in air and in vacuum (3 x 105torr) has been carried out. In vacuum, roughness-induced closure is responsible for closure in the near-threshold region and the level of closure is independent of ??. The presence of oxygen in the environment (50% relative humidity) can increase the overall closure level by as much as 50% in the case of 4135 and 2 1/4Cr 1Mo steels, but does not contribute significantly to closure in the case of the 9Cr 1Mo steel. Roughness-induced closure increases increasing the tempering temperature, but the extent of the environmental effect on closure in a given alloy is a lot less dependent on the tempering temperature. Rewelding is not responsible for the high threshold levels found in vacuum. Oxide film rupture and as well as hydrogen embrittlement increase the crack growth rate in air compared to the observed in vacuum. (Author)

1987-10-19

191

A study of the growth and decay of cigarette smoke NOx in ambient air under controlled conditions  

Energy Technology Data Exchange (ETDEWEB)

The amount of NO{sub 2} and NO produced by the machine smoking of cigarettes was determined for 15 commercial Canadian brands. Average yield of NO was 1.44 {mu}moles or about 13% of the average reported for American cigarettes. Levels of NO{sub 2} were all less than 12% of NO and were probably due to the oxidation of NO. In order to assess the contribution of tobacco smoke to levels of NO in ambient air, 5 brands of cigarettes were smoked in a 27 cubic meter controlled environment room. Ventilation conditions were either 2.5 or 5.0 air changes per hour (ACH) and each experiment was replicated 3 times for a total of 30 experiments. Ventilation rates of 0.3 and 1.5 ACH were also selected in a second series of experiments in which only one brand of cigarette was smoked. Least squares estimates for the effective ventilation rates were obtained in the usual manner after linearizing the decay portion of the NO time curve. In each of the experiments, the regression explained at least 95% of the variation in the levels of NO with time. Loss of NO due to factors other than ventilation appeared to be constant within experimental error and averaged 2.22 ACH. Equilibrium values for NO were grossly underestimated when results from currently accepted procedures for smoke analysis were used in modeling the growth and decay of NO. Goodness-of-fit was improved when equilibrium values were estimated based on observed levels in ambient air.

Rickert, W.S.; Robinson, J.C. (Labstat Inc., Kitchener, Ontario (Canada)); Collishaw, N.E. (Environmental Health Centre, Health and Welfare Canada, Ottawa, Ontario (Canada))

1987-01-01

192

Ozone Pollution  

Medline Plus

Full Text Available ... studies have confirmed that ozone harms people at levels currently found in the United States. In the ... ultraviolet radiation. However, ozone air pollution at ground level where we can breathe it (in the troposphere) ...

193

Ozone Pollution  

Medline Plus

Full Text Available ... A, Schwartz J. The Effect of Ozone and PM10 on Hospital Admissions for Pneumonia and Chronic Obstructive ... A, Schwartz J. The Effect of Ozone and PM10 on Hospital Admissions for Pneumonia and Chronic Obstructive ...

194

Ozone Pollution  

Medline Plus

Full Text Available ... Report Card Widget Or Enter Your Zip Code: Ozone Pollution It may be hard to imagine that pollution could be invisible, but ozone is. The most widespread pollutant in the U.S. ...

195

Ozone Pollution  

Medline Plus

Full Text Available ... Premature death Immediate breathing problems Cardiovascular effects Long-term exposure risks EPA finds ozone causes harm Get ... provided evidence of the impact of even short-term exposure to ozone on healthy, active adults in ...

196

Ozone Pollution  

Medline Plus

Full Text Available ... even when other pollutants also exist. 12 Even low levels of ozone may be deadly. A large study ... subjects performing light exercise while exposed to a low level of ozone. Toxicol Ind Health . 1995; 11: 369- ...

197

Ozone Pollution  

Medline Plus

Full Text Available ... of Ozone and PM10 on Hospital Admissions for Pneumonia and Chronic Obstructive Pulmonary Disease: a national multicity ... of Ozone and PM10 on Hospital Admissions for Pneumonia and Chronic Obstructive Pulmonary Disease: a national multicity ...

198

Ozone Pollution  

Medline Plus

Full Text Available ... to ozone levels in their community. 21 This research provides increasing evidence that ozone may harm newborns. ... your body’s response to other pollutants. For example, research warns that breathing sulfur dioxide and nitrogen oxide— ...

199

Ozone Pollution  

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Full Text Available ... to the effects of breathing ozone: children and teens; 2 anyone 65 and older; 3 people who ... genes were more likely to develop asthma as adolescents in response to the variations in ozone levels ...

200

Ozone Pollution  

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Full Text Available ... shields us from much of the sun’s ultraviolet radiation. However, ozone air pollution at ground level where ... linked exposures to high ozone levels for as little as one hour to a particular type of ...

 
 
 
 
201

Ozone Pollution  

Medline Plus

Full Text Available ... breathing problems Cardiovascular effects Long-term exposure risks EPA finds ozone causes harm Get the Flash Player ... percent lower than the U.S. Environmental Protection Agency (EPA) currently considers safe. Researchers found that ozone at ...

202

Ozone Pollution  

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Full Text Available ... of the most dangerous. Scientists have studied the effects of ozone on health for decades. Hundreds of ... Your Health Premature death Immediate breathing problems Cardiovascular effects Long-term exposure risks EPA finds ozone causes ...

203

Ozone Pollution  

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Full Text Available ... the stratosphere) shields us from much of the sun’s ultraviolet radiation. However, ozone air pollution at ground ... sources. When these gases come in contact with sunlight, they react and form ozone smog. The essential ...

204

Ozone Pollution  

Medline Plus

Full Text Available ... death Immediate breathing problems Cardiovascular effects Long-term exposure risks EPA finds ozone causes harm Get the ... evidence of the impact of even short-term exposure to ozone on healthy, active adults in a ...

205

Organometallic chemical vapor deposition: The roles of precursor design and growth ambient in film properties  

International Nuclear Information System (INIS)

Examples of chemical control in CVD of metallic and ceramic films are highlighted. Specific attention is paid to the complexity of precursor design. The effect of reactor environment on growth chemistry is investigated. Examples where reducing or oxidizing atmosphere provide a high level of control over deposit composition are outlined. The system examined centers on yttrium and yttria. These materials are, in general, desired less for their optical or electronic properties and more for their structural properties. Thus, the rigid purity demands of the microelectronics industry are somewhat relaxed. Nevertheless, critical attention must be paid to the issues of vapor pressure and decomposition profile. Where sufficient data is available to justify it, some explanation of the issues relevant to vapor pressure is presented

1994-12-02

206

ESTIMATION OF INDIVIDUAL OZONE EXPOSURES USING MICROENVIRONMENT MEASUREMENTS  

Science.gov (United States)

Estimates of an individual's ozone exposure were generated for a panel of 51 asthmatic study subjects using ambient ozone concentrations, the relationships observed between the ambient concentrations and the concentrations found in each of two broad classes of environments and kn...

207

Hafnium silicate formation by ultra-violet/ozone oxidation of hafnium silicide  

International Nuclear Information System (INIS)

We report the room temperature growth of hafnium silicate by ultra-violet/ozone oxidation of hafnium silicide. Hafnium silicide was deposited by magnetron sputtering on hydrogen terminated (1 0 0) Si. The film was then exposed to UV radiation while in an O2 ambient. Hafnium silicate films are obtained with no detectable SiOx interfacial layer as characterized by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy

2003-02-03

208

Ozone Pollution  

Medline Plus

Full Text Available ... 2010-2012 compared to 2009-2011. Of the 25 metro areas most polluted by ozone, 22 had ... in the 2013 report. Twenty-two of the 25 most ozone-polluted cities had more high ozone ...

209

Ozone Pollution  

Medline Plus

Full Text Available ... of the deadly impact of ozone in large studies conducted cities across the U.S., in Europe and in Asia. Researchers repeatedly found that the risk of premature death increased with higher levels of ozone. 9 . 10 11 . Newer research has confirmed that ozone increased the risk of premature death ...

210

Ozone Pollution  

Medline Plus

Full Text Available ... can breathe it (in the troposphere) causes serious health problems. Where Does Ozone Come From? Ozone develops in the atmosphere from gases that come out of tailpipes, smokestacks and many other sources. When these gases come in contact with sunlight, they react and form ozone smog. The essential ...

211

Plant Species Sensitivity Distributions for ozone exposure  

International Nuclear Information System (INIS)

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

2013-07-01

212

High ambient temperature alleviates the inflammatory response and growth depression in pigs challenged with Escherichia coli lipopolysaccharide.  

Science.gov (United States)

Pig production has increased in hot climate countries over recent years, but the effect of exposure to high temperatures on the health status of farm animals has not been investigated thoroughly. It is not clear how the ambient temperature (Ta) might influence responses to inflammatory challenge in pigs. The aim of the present study was to evaluate the effects of high Ta on performance and physiological parameters of growing pigs, subjected to repeated administration of Escherichia coli lipopolysaccharide (LPS). Thirty-seven pigs, each fitted with a jugular catheter, were assigned to one of two Ta conditions: thermo-neutral (TN, 24?°C) or high (HT, 30?°C). After a 14-day adaptation period, and a 7-day measurement period, pigs were administered five repeated injections of LPS at 48?h intervals. Irrespective of Ta, the LPS challenge reduced feed consumption and increased plasma pro-inflammatory cytokines, haptoglobin and cortisol. However, the extent of these responses was greater in pigs at TN than HT. In both groups, plasma thyroxine and triiodothyronine concentrations decreased, following the first LPS injection and thereafter returned to baseline, which occurred faster at HT than at TN. Moreover, the LPS challenge decreased growth and feed efficiency in pigs kept at TN, which was not observed in pigs kept at HT. The results suggest a greater capacity of pigs to limit the physiological and metabolic disturbances caused by inflammatory challenge, when kept at HT, compared to TN. PMID:24792207

Campos, Paulo H R F; Merlot, Elodie; Damon, Marie; Noblet, Jean; Le Floc'h, Nathalie

2014-06-01

213

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

Science.gov (United States)

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.

Chen, Xiaoying; Song, Fengbin; Liu, Fulai; Tian, Chunjie; Liu, Shengqun; Xu, Hongwen; Zhu, Xiancan

2014-01-01

214

Ozone measurement systems: associated instrumentation and calibration  

Directory of Open Access Journals (Sweden)

Full Text Available The harmful effects produced by ozone have lead to a vast regulation to define and establish the quality goals of ambient air, based on common methods and criteria. The surveillance nets of atmospheric pollution are worldwide extended systems and the applied technology for the ozone measurement is nowadays quite standardized. The aim of this paper is to give a general view of the most common systems used in the ozone measurement in ambient air from a practical point of view. The used instrumentation and the usual calibration methods will be described.

J. Bellido

2006-01-01

215

Effects of ozone on the sporulation, germination, and pathogenicity of Botrytis cinerea  

Energy Technology Data Exchange (ETDEWEB)

Studies were initiated to determine if Botrytis cinerea conidia remain viable when grown in vivo and in vitro in the presence of ambient ozone levels and whether ozonized conidia retain pathogenicity. Experimental materials and methods used are described.

Krause, C.R.; Weidensaul, T.C.

1978-02-01

216

Crescimento de Aegla manuinflata (Decapoda, Anomura, Aeglidae) em ambiente natural / Growth of Aegla manuinflata (Decapoda, Anomura, Aeglidae) in natural environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O presente trabalho teve como objetivo avaliar o crescimento de Aegla manuinflata Bond-Buckup & Santos, 2009 em ambiente natural. Para isso foram realizadas coletas mensais de abril de 2006 a maio de 2007 no arroio Passo Taquara, no município de São Pedro do Sul, Rio Grande do Sul, Brasil. Os organi [...] smos foram coletados utilizando armadilhas plásticas e puçá. Os espécimes foram sexados e tiveram mensurado o comprimento do cefalotórax (CC), em seguida foram devolvidos ao córrego. O crescimento foi avaliado utilizando o modelo de von Bertalanffy. As curvas de crescimento do cefalotórax, estimadas para machos e fêmeas, são descritas pelas seguintes equações Ct = 28,00 [1 - e-0,0047(t+10,63)] e Ct = 25,16 [1 - e-0,0051(t+17,65)], respectivamente. Os machos atingem tamanhos maiores que as fêmeas. A longevidade foi estimada em três anos para os machos e dois anos e meio para as fêmeas. Abstract in english The aim of this work was to evaluate the growth of Aegla manuinflata Bond-Buckup & Santos, 2009 in natural environment. Samplings were monthly performed, from April/2006 to May/2007, in a tributary of Ibicuí-Mirim River, which belongs to the Uruguay River basin, at São Pedro do Sul municipality, sta [...] te of Rio Grande do Sul, Brazil. Traps and dip nets were used to collect the animals. The specimens were sexed and had their cephalothoracic length (CL) measured, using a digital caliper with 0.01 mm precision. The growth was evaluated using the von Bertalanffy model. The growth curves in length (mm), for the data obtained through the modal progression, are described by the equations: Ct = 28.00 [1 - e-0.0047(t+10.63)] for males and Ct = 25.16 [1 - e-0.0051(t+17.65)] for females. The maximum estimated age for males was three years and for females was two years and six months.

Trevisan, André; Santos, Sandro.

217

Adjustments of net photosynthesis in Solanum tuberosum in response to reciprocal changes in ambient and elevated growth CO{sub 2} partial pressures  

Energy Technology Data Exchange (ETDEWEB)

Single leaf photosynthetic rates and various leaf components of potato (Solanum tuberosum L.) were studied 1-3 days after reciprocally transferring plants between the ambient and elevated growth CO{sub 2} treatments. Plants were raised from individual tuber sections in controlled environment chambers at either ambient (36 Pa) or elevated (72 Pa) CO{sub 2}. One half of the plants in each growth CO{sub 2} treatment were transferred to the opposite CO{sub 2} treatment 34 days after sowing (DAS). Net photosynthesis (P{sub n}) rates and various leaf components were then measured 34, 35 and 37 DAS at both 36 and 72 Pa CO{sub 2}. Three-day means of single leaf P{sub n} rates, leaf starch, glucose, initial and total Rubisco activity, Rubisco protein, chlorophyll (a+b), chlorophyll (a/b), {alpha}-amino N, and nitrate levers differed significantly in the continuous ambient and elevated CO{sub 2} treatments. Acclimation of single leaf P{sub n} rates was partially to completely reversed 3 days after elevated CO{sub 2}-grown plants were shifted to ambient CO{sub 2} whereas there was little evidence of photosynthetic acclimation 3 days after ambient CO{sub 2}-grown plants were shifted to elevated CO{sub 2}. In a four-way comparison of the 36, 72, 36 to 72 (shifted up) and 72 to 36 (shifted down) Pa CO{sub 2} treatments 37 DAS, leaf starch soluble carbohydrates, Rubisco protein and nitrate were the only photosynthetic factors that differed significantly. Simple and multiple regression analyses suggested that negative changes of P{sub n} in response to growth CO{sub 2} treatment were most closely correlated with increased leaf starch levels. (au)

Sicher, R.C.; Bunce, J.A. [USDA Agricultural Res. Service, Climate Stress Lab., Beltsville, MD (United States)

2001-07-01

218

Ozone Climatology  

Science.gov (United States)

The primary role of models in the assessment process is to predict changes to ozone. It is crucial therefore that the ability of the models to reproduce the actual distribution of ozone be tested. Historically, maps of the ozone column (latitude by month) have been used for this purpose. In MM I a climatology was developed for the vertical distribution of ozone for 15-60 km, based on SBUV data for 1979-80. SBUV profiles are reported with vertical resolution of approx. 5 km, but the true resolution is lower, approx. 8 km above the ozone maximum and approx. 15 km for 10-25 km. The climatology was considered valid to about 20-30% at 20 km and to 50% at 15 km. Comparisons were made with models in mixing ratio (ppm), which emphasizes the middle and upper stratosphere. A new ozone climatology was developed for the vertical distribution of ozone for MM II. Our goal was to develop a product that could be used to evaluate models in the lower stratosphere, the region where most of the ozone column resides and where most of the ozone loss is occurring, as well as the middle and upper stratosphere.

Logan, Jennifer A.; McPeters, Richard D.

1999-01-01

219

Effects of ozone on yield of two field-grown barley cultivars  

Energy Technology Data Exchange (ETDEWEB)

Barley Hordeum vulgare L. is grown in some regions of the USA with potentially phytotoxic concentrations of ozone (O/sub 3/), yet relatively little is known of the growth and yield responses of this crop species to O/sub 3/. A two-year study was conducted in the Central Valley of California to determine yield responses of two cultivars of spring barley grown in open-top chambers to a gradient of O/sub 3/ concentrations. Ozone concentrations were maintained in chambers in proportion to ambient levels. Exposure levels ranged from charcoal-filtered air to twice ambient concentrations. Results indicated that neither Poco, grown in 1982, not CM-72, used in 1983, was injured or reduced in growth by the relatively low ambient O/sub 3/ concentrations (0.03-0.05 ..mu..l liter/sup -1/) found in late winter or spring in the Central Valley. Twice ambient concentrations of O/sub 3/ also had no effect on the growth and yield of these cultivars. These results suggest that the threshold for an effect of O/sub 3/ on the yield of these cultivars of spring barley is above a seasonal 7 h (0900-1600) mean of 0.06 ..mu..l liter/sup -1/.

Temple, P.J.; Taylor, O.C.; Benoit, L.F.

1985-01-01

220

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

Energy Technology Data Exchange (ETDEWEB)

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

Paoletti, Elena [IPP-CNR, Via Madonna del Piano 10, Sesto Fiorentino, I-50019 Florence (Italy)], E-mail: e.paoletti@ipp.cnr.it; Contran, Nicla [Department of Environmental Sciences, 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); Castagna, Antonella; Ranieri, Annamaria [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, Pisa (Italy); Tagliaferro, Francesco [IPLA, Corso Casale 476, I-10128 Turin (Italy)

2008-10-15

 
 
 
 
221

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

International Nuclear Information System (INIS)

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

2008-10-01

222

Ozone contamination in aircraft cabins: Results from GASP data and analyses  

Science.gov (United States)

The global atmospheric sampling program pertaining to the problem of ozone contamination in commercial airplane cabins is described. Specifically, analyses of GASP data have: confirmed the occurrence of high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; defined ambient ozone climatology at commercial airplane cruise altitudes, including tabulation of encounter frequency data which were not available before GASP; and outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data, and verified these procedures against cabin measurements.

Holdeman, J. D.; Nastrom, G. D.

1981-01-01

223

Ozone contamination in aircraft cabins - Results from GASP data and analyses  

Science.gov (United States)

The paper reviews results from the NASA Global Atmospheric Sampling Program (GASP) pertaining to the problem of ozone contamination in commercial aircraft cabins. Specifically, analyses of GASP data have (1) confirmed the high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; (2) defined ambient ozone climatology at commercial aircraft cruise altitudes, including tabulation of encounter frequency data; and (3) outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data and verified these procedures against cabin measurements.

Holdeman, J. D.; Nastrom, G. D.

1981-01-01

224

Ozone Pollution  

Medline Plus

Full Text Available ... city in the nation to install an air quality warning flag system on the beach. 8 How Ozone Pollution Harms Your Health Premature death . Breathing ozone can shorten your life. Strong evidence exists of the deadly impact of ...

225

Ozone Pollution  

Medline Plus

Full Text Available ... developmental harm —U.S. Environmental Protection Agency, Integrated Science Assessment for Ozone and Related Photochemical Oxidants , 2013. EPA/ ... References 1 . U.S. Environmental Protection Agency. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report) . ...

226

Ozone Pollution  

Medline Plus

Full Text Available ... exists of the deadly impact of ozone in large studies conducted cities across the U.S., in Europe ... low levels of ozone may be deadly. A large study of 48 U.S. cities looked at the ...

227

Ozone Pollution  

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Full Text Available ... and developmental harm —U.S. Environmental Protection Agency, Integrated Science Assessment for Ozone and Related Photochemical Oxidants , 2013. ... 076F. References 1 . U.S. Environmental Protection Agency. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final ...

228

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

Science.gov (United States)

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O(3)) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb(v) of O(3) (NF +). The photochemical maximal efficiency, Fv/Fm, decreased in NF + plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of delta(13)C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF + treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in delta(15)N were found in all species during the second year when exposed in the NF + OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, delta(15)N, chlorophyll, leaf area, LMA and biomass occurred at ambient O(3) concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF + treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. PMID:15589656

Ribas, Angela; Peñuelas, Josep; Elvira, Susana; Gimeno, Benjamín S

2005-03-01

229

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

International Nuclear Information System (INIS)

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

2004-09-01

230

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 crescimen...

Rosa Baeza; Cristina Rossler; Diana Mielnicki; María Clara Zamora; Jorge Chirife

2009-01-01

231

Effect of ozone on the in vitro synthesis and release of inflammatory mediators and growth factors by alveolar macrophages derived from patients with chronic bronchopulmonary inflammation; Wirkung von Ozon auf die in vitro-Bildung und -Freisetzung von Entzuendungsmediatoren und Wachstumsfaktoren durch Alveolarmakrophagen bei Patienten mit chronisch bronchopulmonalen Entzuendungen  

Energy Technology Data Exchange (ETDEWEB)

The effect of ozone exposure on cytokine release was studied in alveolar macrophages (AM) from patients with chronic inflammatory lung disease. AM of 87 patients entered 99 exposure experiments (13 at 150 {mu}g, 32 at 300 {mu}g, 16 at 700 {mu}g, and 38 at 1000 {mu}g ozone/m{sup 3}). AM were exposed in a biphasic system consisting of membrane-culture insert of high porosity (transwell). AM were directly exposed to ozone for 1 h, followed by 4 h of culture covered with serum-free medium. The parameters were determined in culture supernatant by ELISA (interleukin (IL) 1{alpha}, {beta}, IL6, IL8, TNF{alpha}), by bioassay (TNF{alpha}), and by enzyme assay (LDH). By increased LHD activities in culture supernatants of ozone exposed AM, a significant cytotoxic effect was identified for ozone concentrations equal to or higher than 300 {mu}g/m{sup 3}. Spontaneous release of IL1{alpha}, {beta} and IL8 slightly increased after ozone exposure (p<0,05 at 150 {mu}g ozone). TNF was released in reduced quantities (p<0,05 at 300 {mu}g; p<0,01 at 1000 {mu}g ozone/m{sup 3}). Patients with chronic bronchitis, fibrosis, and sarcoidosis differed significantly in basic cytokine release of IL1{alpha}, IL1{beta}, IL8, and TNF, with sarcoidosis patients showing the highest levels of cytokines measured. Nevertheless, the ozone induced changes for the various cytokines were not significantly different between the above patient groups. The most obvious effect of ozone could be observed after additional stimulation of AMs with LPS. LPS induced secretion of TNF and IL6 were shown to be strongly inhibited by ozone, even at ambient concentrations (150 and 300 {mu}g/m{sup 3}). Little effect was seen regarding IL8, IL1{alpha}, and {beta}. The murine macrophage cell line J774A.1, which proved to respond to LPS stimulation in a similar reduction of TNF release after ozone exposure, was used as a model to study LPS receptor binding. After ozone exposure at 300 {mu}g/m{sup 3} LPS-FITC binding was reduced significantly demonstrating impaired receptor function, whereas detection of receptor by monoclonal anti-CD14-antibody was not altered significantly. In conclusion, ozone impairs macrophage functions even at ambient concentrations, which might interfere with host defence mechanisms. Some, but not all patients might therefore risk of aggravation of their respective disease. Response to ozone seemed to be influenced rather by the individual`s conditions than by the underlying disease. (orig.) [Deutsch] Unter der Fragestellung, ob und wie Ozon die Freisetzung von Entzuendungsmediatoren aus Alveolarmakrophagen (AM) bei Patienten mit chronisch entzuendlichen Lungenerkrankungen beeinflussen kann, wurden im Projekt die AM von 87 Patienten in 99 in vitro Expositionsexperimenten untersucht (13 bei 150 {mu}g, 32 bei 300 {mu}g, 16 bei 700 {mu}g und 38 bei 1000 {mu}g Ozon/m{sup 3}). Die AM wurden in Transwell-Membrankulturgefaessen exponiert und waren apikal der Gasphase 1 Stunde direkt ausgesetzt. Die Befeuchtung erfolgte kapillar von unten durch die poroese Membran hindurch. Nach weiteren 4 Stunden Kultur mit Medium bedeckt, wurden die Parameter im Kulturueberstand gemessen. Eine signifikant toxische Wirkung ist anhand der erhoehten LDH-Aktivitaet im Kulturueberstand der ozonexponierten AM ab 300 {mu}g/m{sup 3} nachweisbar. Von Patient zu Patient gab es fuer die einzelnen Parameter eine grosse individuelle Variabilitaet bezueglich Richtung und Hoehe der Ozonantwort. Die spontane Freisetzung von IL1 {alpha} und {beta} sowie IL8 zeigt im Mittel eine diskrete Zunahme nach Ozon (p<0,05 bei 150 {mu}g), waehrend fuer TNF zumeist eine Hemmung festzustellen ist (p<0,05 bei 300 {mu}g; p<0,01 bei 1000 {mu}g Ozon). Die Patientengruppen Sarkoidose, Fibrose und Bronchitis unterscheiden sich in ihrer Basisfreisetzung, wobei die AM von Sakroidosepatienten fuer die untersuchten Zytokine die hoechsten Sekretionsraten aufweisen. Die ozonbedingte Sekretionsaenderung zeigt keine signifikanten Unterschiede in Hoehe und Auslenkung zwischen den Patientengruppen. Der staerkst

Muley, T.; Segraefe, P.; Ebert, W. [Thoraxklinik Heidelberg (Germany). Abt. Klinische Chemie und Bakteriologie; Wiebel, M.; Schulz, V. [Thoraxklinik Heidelberg (Germany). Innere Medizin und Pneumologie

1997-10-01

232

Impact of ozone on understory plants of the aspen zone  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to learn how ozone might affect the growth and reproduction of understory species of the aspen community, and thereby influence its stability and composition. Plants of 15 representative species of the aspen community were grown in chambers and fumigated 4 hours each day, 5 days per week throughout their growing seasons. These included: Achillea millifolium, Chenopodium album, Chenopodium fremontii, Cruciferae sp., Descurainia pinnata, Descurainia sp., Geranium fremontii, Isatis tinctoria, Ligusticum porteri, Lepidium virginicum, Madia glomerata, Polygonum aviculare, Polygonum douglasii, Phacelia heterophylla, Viola italica. Plants were exposed to 30 pphm, 15 pphm, ambient air reaching 5-7 pphm for 2 hours per day, and filtered air. The study was repeated for 3 seasons. Ambient air caused a significant reduction of total plant weight only of Lepidium virginicum. Six species produced fruit and seeds. At 15 pphm, seed production by Madia glomerata and Polygonum douglasii was significantly reduced. At 30 pphm, seed production was also reduced in Polygonum aviculare and Lepidium virginicum. The two most significant conclusions to emerge from the study were first that several species were more sensitive to ozone than might have been suspected. Second, this sensitivity varied sufficiently that major shifts in community composition would be probable following only a year or two of exposure. More tolerant species have no doubt already become dominant over more sensitive species in natural plant communities exposed to elevated ozone concentrations. It must be stressed that the species studied did not necessarily represent the most ozone sensitive members of the community, or the most tolerant.

Harward, M.R.; Treshow, M.

1971-01-01

233

Intraspecific variation in sensitivity to ambient ultraviolet-B radiation in growth and yield characteristics of eight soybean cultivars grown under field conditions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The present study was conducted with eight cultivars of soybean (Glycine max) to determine the effect of exclusion of solar UV-B on the vegetative growth (plant height, leaf area, no. of nodes), UV absorbing compounds (implicated in UV protection) and crop yield (No. of pods and seed weight) and to [...] determine the cultivar difference in their sensitivity to ambient UV-B. Exclusion of solar UV-B enhanced the vegetative growth and yield of all the soybean cultivars. The results showed a significant inverse association between the enhancement in vegetative growth and number of pods among the cultivars tested, indicating differences in the carbon partitioning amongst the cultivars by the way of exclusion of solar UV-B. NRC-7, Pusa-24 and JS-335 showed maximum promotion in vegetative growth and less enhancement in crop yield after solar UV-B exclusion. Kalitur, JS71-05, Hardee, PK-472 and PK-1029 showed improved performance both in terms of number of pods/plant and seed weight after solar UV-B exclusion. An enhancement in the crop yield by exclusion of solar UV-B indicated poor response of the cultivar to the ambient solar UV-B; these cultivars would be more suitable at latitudes, which received less UV-B. According to UV-SI, sensitivity of eight Indian soybean cultivars to ambient level of UV-B (280-320 nm) radiation had the following descending order; PK-472 > JS-335 > Hardee > Kalitur > JS71-05 > Pusa-24 > NRC-7 > PK-1029. These findings suggest the way to select the best-suited cultivar for particular latitude.

Baroniya, Sanjay S.; Kataria, Sunita; Pandey, G.P.; Guruprasad, Kadur N..

234

Ozone modeling  

International Nuclear Information System (INIS)

Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO_2), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NO_x concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NO_x coordinates of the point, known as the NMOC/NO_x ratio. Results obtained by the described model are presented

1994-07-01

235

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

DEFF Research Database (Denmark)

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 fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 268C), one (HC; 168C to 268C) or no (CC; 168C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating 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 ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Nielsen, Birte Lindstrøm

2012-01-01

236

Ozone uptake by citrus trees exposed to a range of ozone concentrations  

Science.gov (United States)

The Citrus genus includes a large number of species and varieties widely cultivated in the Central Valley of California and in many other countries having similar Mediterranean climates. In the summer, orchards in California experience high levels of tropospheric ozone, formed by reactions of volatile organic compounds (VOC) with oxides of nitrogen (NO x). Citrus trees may improve air quality in the orchard environment by taking up ozone through stomatal and non-stomatal mechanisms, but they may ultimately be detrimental to regional air quality by emitting biogenic VOC (BVOC) that oxidize to form ozone and secondary organic aerosol downwind of the site of emission. BVOC also play a key role in removing ozone through gas-phase chemical reactions in the intercellular spaces of the leaves and in ambient air outside the plants. Ozone is known to oxidize leaf tissues after entering stomata, resulting in decreased carbon assimilation and crop yield. To characterize ozone deposition and BVOC emissions for lemon ( Citrus limon), mandarin ( Citrus reticulata), and orange ( Citrus sinensis), we designed branch enclosures that allowed direct measurement of fluxes under different physiological conditions in a controlled greenhouse environment. Average ozone uptake was up to 11 nmol s -1 m -2 of leaf. At low concentrations of ozone (40 ppb), measured ozone deposition was higher than expected ozone deposition modeled on the basis of stomatal aperture and ozone concentration. Our results were in better agreement with modeled values when we included non-stomatal ozone loss by reaction with gas-phase BVOC emitted from the citrus plants. At high ozone concentrations (160 ppb), the measured ozone deposition was lower than modeled, and we speculate that this indicates ozone accumulation in the leaf mesophyll.

Fares, Silvano; Park, Jeong-Hoo; Ormeno, Elena; Gentner, Drew R.; McKay, Megan; Loreto, Francesco; Karlik, John; Goldstein, Allen H.

2010-09-01

237

Inhibitory effects of ambient levels of solar UV-A and UV-B radiation in growth of cv. New Red Fire lettuce  

Energy Technology Data Exchange (ETDEWEB)

The influence of solar UV-A and UV-B radiation at Beltsville, MD, USA, on growth of Lactuca sativa L. (cv. New Red Fire lettuce) was examined during early summer of 1996 and 1997. Plants were grown from seed in plastic window boxes covered with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or tefzel (1996) or teflon (1997) to transmit UV-A and UV-B radiation. After 31-34 days, plants grown in the absence of solar UV-B radiation (polyester) had 63 and 57% greater fresh weight and dry weight of tops, respectively, and 57, 72 and 47% greater dry weight of leaves, stems and roots, respectively, as compared to those grown under ambient UV-B (tefzel or teflon). Plants protected from UV-A radiation as well (Llumar) showed an additional 43 and 35% increase, respectively, in fresh and dry weight of tops and a 33 and 33% increase, respectively, in dry weight of leaves and stems, but no difference in root biomass over those grown under polyester. Excluding ambient UV-B (polyester) significantly reduced the UV absorbance of leaf extracts at 270, 300 and 330 nm (presumptive flavonoids) and the concentration of anthocyantins at 550 nm as compared to those of leaf extract from plants grown under ambient UV-A and UV-B. Additional removal of ambient UV-A (Llumar) reduced the concentration of anthocyanins, but had no further effect on UV absorbance at 270, 300 or 330 nm. These findings provide evidence that UV-B radiation is more important than UV-A radiation for flavonoid induction in this red-pigmented lettuce cultivar. Although previous workers have obtained decreases in lettuce yield under enhanced UV-B, this is the first evidence for inhibitory effects of solar UV-A and UV-B radiation on lettuce growth. (au) 34 refs.

Krizek, D.T.; Britz, S.J.; Mirecki, R.M. [Climate Stress Laboratory, Beltsville, MD (United States)

1998-05-01

238

Ozone Depletion  

Science.gov (United States)

Discussion of holes in the stratospheric ozone layer usually revolves around investigations of the thickness of the layer near the South Pole. This online activity allows users to study the thickness of the ozone layer over any location on Earth to see how it has changed over time. This is done by plotting historical data from the Total Ozone Mapping Spectrometer (TOMS) Program, which has been in operation since 1978. Users are allowed to select their own location on Earth and the period over which they plot the data. A link to TOMS datasets is provided.

Pratte, John

239

Ozone layer  

Energy Technology Data Exchange (ETDEWEB)

Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.

Mintzer, I.M.; Miller, A.S.

1987-12-01

240

Characterization of ozone episodes in urban air  

International Nuclear Information System (INIS)

The study was directed toward analysis and quantitation of some of the factors that precede the development of ozone episodes in an urban setting. Measurements of pollution and meteorological data were collected in Chicago during August and early September for 54 consecutive days in 1976 and 39 consecutive days in 1977. During these periods, regular measurements were made of the ozone-forming potential of ambient air. Rise in ozone levels was related to passage of a weather front. A method was developed and tested for measuring the ozone-forming potential of ambient air. A rough association was observed between this measurement and O3(max) 3 and 4 days later for the same frontal system

1979-01-01

 
 
 
 
241

Ozone as an ecotoxicological problem  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1996-11-01

242

Effects of long-term ozone exposure and soil-moisture deficit on growth of a ladino clover-tall fescue pasture  

Energy Technology Data Exchange (ETDEWEB)

Most field studies relating seasonal ozone (O3) exposure to crop yield have been performed in the absence of plant moisture stress. The authors examined the response of a mixture of ladino clover and tall fescue to chronic doses of O3 at two soil-moisture levels over two growing seasons. The soil-moisture treatments, obtained by differential irrigation, were well-watered or water-stressed. A soil-moisture deficit occurred intermittently in water-stressed plots during both seasons. Shoots were harvested when plants reached a height of 20-25 cm. Total forage yield in the water stressed plots was 12-14% less than that in the well-watered plots. Clover was much more sensitive than fescue to O3. The decrease in total forage yield and decreased quality caused by decreased growth of clover suggest a need for ladino clover lines that are tolerant to O3.

Heagle, A.S.; Rebbeck, J.; Shafer, S.R.; Blum, U.; Heck, W.W.

1988-01-01

243

Ozone Pollution  

Medline Plus

Full Text Available ... pollutants. For example, research warns that breathing sulfur dioxide and nitrogen oxide—two pollutants common in the ... FD. Birth outcomes and prenatal exposure to ozone, carbon monoxide, and particulate matter: Results from the Children's ...

244

Ozone Pollution  

Medline Plus

Full Text Available ... 1095; Alexeeff SE, Litonjua AA, Suh H, Sparrow D, Vokonas PS, Schwartz J. Ozone exposure and lung function: Effect modified by obesity and airways hyperresponsiveness in the ...

245

Ozone Pollution  

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Full Text Available ... Air Agencies U. S. Environmental Protection Agency sites: Clean School Bus USA Information for Citizens and Communities National ... Smart links footer - Homepage Key Findings Ozone Pollution Year Round Particle Short Term Particle Cleanest Cities People ...

246

Ozone Pollution  

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Full Text Available ... healthy, active adults in a study published in 2008. Testing the breathing capacity of these outdoor workers ... vulnerable to die from ozone air pollution? Epidemiology. 2008; 19: 672-679. 4 . Thaller EI, Petronell SA, ...

247

Ozone Pollution  

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Full Text Available ... Short-term effect of concentrations of fine particulate matter on hospital admissions due to cardiovascular and respiratory ... prenatal exposure to ozone, carbon monoxide, and particulate matter: Results from the Children's Health Study. Environ Health ...

248

Ozone Pollution  

Medline Plus

Full Text Available ... The essential raw ingredients for ozone come from nitrogen oxides (NOx), hydrocarbons, also called volatile organic compounds ( ... example, research warns that breathing sulfur dioxide and nitrogen oxide—two pollutants common in the eastern U.S.— ...

249

Ozone Pollution  

Medline Plus

Full Text Available ... They are produced primarily when fossil fuels like gasoline, oil or coal are burned or when some ... or driving your car. Lawn mower exhaust and gasoline vapors are VOCs that could turn into ozone ...

250

Ozone Pollution  

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Full Text Available ... research, Galveston became the first city in the nation to install an air quality warning flag system ... 13 Immediate breathing problems . Many areas in the United States produce enough ozone during the summer months ...

251

Ozone Pollution  

Medline Plus

Full Text Available ... Photochemical Oxidants , 2013. EPA/600/R-10/076F. References 1 . U.S. Environmental Protection Agency. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final ...

252

Ozone Pollution  

Medline Plus

Full Text Available ... 360: 1085-1095; Alexeeff SE, Litonjua AA, Suh H, Sparrow D, Vokonas PS, Schwartz J. Ozone exposure ... with Asthma. JAMA .2003; 290:1859-1867; Desqueyroux H, Pujet JC, Prosper M, Squinazi F, Momas I. ...

253

Ozone Pollution  

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Full Text Available ... data from their long-term Southern California Children’s Health Study found that some children with certain genes were more likely to develop asthma as adolescents in response to the variations in ozone levels ...

254

Ozone Pollution  

Medline Plus

Full Text Available ... J. Short-term effect of concentrations of fine particulate matter on hospital admissions due to cardiovascular and ... and prenatal exposure to ozone, carbon monoxide, and particulate matter: Results from the Children's Health Study. Environ ...

255

Ozone Pollution  

Medline Plus

Full Text Available ... SE, Litonjua AA, Suh H, Sparrow D, Vokonas PS, Schwartz J. Ozone exposure and lung function: Effect ... Health . 2010; 124: 28-36; Middleton N, Yiallouros P, Kleanthous S, Kolokotroni O, Schwartz J, et al. A ...

256

Ozone Pollution  

Medline Plus

Full Text Available ... 2007 ; 6: 40. 3 . Medina-Ramón M, Schwartz J. Who is more vulnerable to die from ozone ... Associated With Lung Function Decreases in Beach Lifeguards. J Occp Environ Med. 2008; 50: 202-211. Sawyer ...

257

Ozone Pollution  

Medline Plus

Full Text Available ... J. Short-term effect of concentrations of fine particulate matter on hospital admissions due to cardiovascular and respiratory ... and prenatal exposure to ozone, carbon monoxide, and particulate matter: Results from the Children's Health Study. Environ Health ...

258

Ozone Pollution  

Medline Plus

Full Text Available ... molecule of three oxygen atoms. Ozone attacks lung tissue by reacting chemically with it. To learn more, ... number does not include people who live in adjacent counties in metropolitan areas where no monitors exist. ...

259

Ozone Pollution  

Medline Plus

Full Text Available ... more vulnerable to die from ozone air pollution? Epidemiology. 2008; 19: 672-679. 4 . Thaller EI, Petronell ... the National Morbidity, Mortality, and Air Pollution Study. Epidemiology. 2005; 16:436-445. Levy JI, Chermerynski SM, ...

260

Ozone Pollution  

Medline Plus

Full Text Available ... increase the response to allergens in people with allergies. A large study published in 2009 found that ... likely to suffer from hay fever and respiratory allergies when ozone and PM2.5 levels were high. ...

 
 
 
 
261

Ozone Pollution  

Medline Plus

Full Text Available ... al., 2008. 9 . Bell ML, McDermott A, Zeger SL, Samet JM, Dominici F. Ozone and short-term ... TW, Lau TS, Yu TS, Neller A, Wong SL, Tam W, Pang SW. Air pollution and hospital ...

262

Ozone Pollution  

Medline Plus

Full Text Available ... nation to install an air quality warning flag system on the beach. 8 How Ozone Pollution Harms ... failure) May cause harm to the central nervous system May cause reproductive and developmental harm —U.S. Environmental ...

263

Ozone Pollution  

Medline Plus

Full Text Available ... chemicals, like solvents, evaporate. NOx is emitted from power plants, motor vehicles and other sources of high- ... nation to install an air quality warning flag system on the beach. 8 How Ozone Pollution Harms ...

264

Fast response cavity enhanced ozone monitor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone is an important atmospheric gas due to its role in air quality and radiative forcing. A new method for sensitive, rapid monitoring of ambient ozone has been developed using a compact platform and relatively inexpensive components. Based on Incoherent Broadband Cavity Enhanced Absorption Spectroscopy (IBB-CEAS), the device utilizes an optical cavity of just 14.5 cm and moderately high reflectivity mirrors (R = 99.3%). Performance of the instrument has been validated...

Gomez, A. L.; Rosen, E. P.

2012-01-01

265

Fast response cavity enhanced ozone monitor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone is an important atmospheric gas due to its role in air quality and radiative forcing. A new method for sensitive, rapid monitoring of ambient ozone has been developed using a compact platform and relatively inexpensive components. Based on incoherent broadband cavity enhanced absorption spectroscopy (IBB-CEAS), the device utilizes an optical cavity of just 14.5 cm and 99.3% reflective mirrors. Performance of the instrument has been validated against direct absorption measurements in a s...

Gomez, A. L.; Rosen, E. P.

2013-01-01

266

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

International Nuclear Information System (INIS)

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 O3), 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

2008-07-01

267

Ozone, Tropospheric  

Science.gov (United States)

In the early part of the 20th century, ground-based and balloon-borne measurements discovered that most of atmosphere's ozone is located in the stratosphere with highest concentrations located between 15 and 30 km (9,3 and 18.6 miles). For a long time, it was believed that tropospheric ozone originated from the stratosphere and that most of it was destroyed by contact with the earth's surface. Ozone, O3, was known to be produced by the photo-dissociation of molecular oxygen, O2, a process that can only occur at wavelengths shorter than 242 nm. Because such short-wave-length radiation is present only in the stratosphere, no tropospheric ozone production is possible by this mechanism. In the 1940s, however, it became obvious that production of ozone was also taking place in the troposphere. The overall reaction mechanism was eventually identified by Arie Haagen-Smit of the California Institute of Technology, in highly polluted southern California. The copious emissions from the numerous cars driven there as a result of the mass migration to Los Angeles after World War 2 created the new unpleasant phenomenon of photochemical smog, the primary component of which is ozone. These high levels of ozone were injuring vegetable crops, causing women's nylons to run, and generating increasing respiratory and eye-irritation problems for the populace. Our knowledge of tropospheric ozone increased dramatically in the early 1950s as monitoring stations and search centers were established throughout southern California to see what could be done to combat this threat to human health and the environment.

Fishman, Jack

1995-01-01

268

Ambient Space and Ambient Sensation  

DEFF Research Database (Denmark)

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, dehierarchization, ubiquity and the production of unfocused sensations in contrast to the conventional notion of the aesthetic experience as a focused contemplation of a stationary object.

Schmidt, Ulrik

269

Effect of an ozone injury retardant chemical on isozyme profiles from alfalfa callus in vitro  

Energy Technology Data Exchange (ETDEWEB)

Plant ozone injury retardant N-(2-(2-oxo-1-imidazolidinyl)-ethyl)-N'-phenylurea (EDU or ethylenediurea) at 1.0 ppm inhibited growth of callus of alfalfa cultivars Williamsburg (ozone-sensitive) and MSB-CW5An2 (ozone-insensitive) germplasm of Medicago sativa. The presence of EDU (0.1 ppm)in the growth medium increased the number of protein and peroxidase isozyme bands in alfalfa cultivar Williamsburg stem callus and ozone modified their intensities. Protein profiles of MSB stem callus from media containing EDU or exposed to ozone were unchanged. Marked differences were observed between the peroxidase profiles of ozonated and control ozone-insensitive stem callus from media containing EDU. Protein profiles of ozonated ozone-sensitive leaf callus differed slightly from controls. The peroxidase profile of ozonated ozone-sensitive leaf callus was not altered when its growth medium contained EDU, but when it was absent, changes were observed in these profiles.

Rier, J.P. Jr.; Sood, V.K.; Whitaker, A.; Watson, C.

1983-01-01

270

Ambient atmosphere bonding of titanium foil to a transparent conductive oxide and anodic growth of titanium dioxide nanotubes  

Energy Technology Data Exchange (ETDEWEB)

Titania nanotubes were fabricated by anodization of titanium foil bonded to fluorine-doped tin oxide-coated glass (FTO) by an adhesion layer of low-melting-temperature metals. The bonding layer characteristics depended on pressure and ambient environment. The bonding composition is similar to lead-free solder and the addition of antimony improved wetting further. This process presents a rapid, low-cost method for obtaining high-quality, anodizable Ti foil on FTO. (author)

Perez-Blanco, Jonathan M. [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States); Barber, Greg D. [Department of Chemistry and Materials Research Institute, Materials Research Institute and Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, PA 16802 (United States)

2008-09-15

271

Ozone fact sheet: the ozone layer  

Energy Technology Data Exchange (ETDEWEB)

The fact sheets deal with such topics as: protection of the ozone layer; what the ozone layer is; what is happening to Canada's ozone layer; ozone-destroying chemicals; ozone depletion over Canada; the polar regions and ozone loss; the impacts of Arctic ozone thinning; research; the impacts of ozone loss; actions to protect the ozone layer; reducing ozone-destroying chemicals; progress in reducing ozone-destroying chemicals; what you can do. Canada has played a key role in protecting the ozone layer, and our nation was instrumental in the development of the Montreal protocol, which is the international agreement to reduce ozone-destroying chemicals. As well, Canada is a world leader in the scientific research which guides international effort to protect the fragile skies. The production of industrial chemicals once a major threat to the earth's ozone layer has been greatly reduced, and levels of some of those chemicals are beginning to decline in the lower atmosphere. The ozone layer is expected to eventually recover, if efforts are maintained by all nations to reduce ozone-destroying chemicals. It will probably be more than a decade before major signs of a recovery are seen, and at least the year 2050 before any substantial recovery occurs. The ozone layer is still thinning, especially at the earth's poles. Mid-latitude areas such as southern Canada and the U.S. are still experiencing ozone thinning.

NONE

1999-07-01

272

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

International Nuclear Information System (INIS)

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

2005-10-01

273

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

274

Effects of ozone on crops in north-west Pakistan  

International Nuclear Information System (INIS)

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

2013-03-01

275

Ozone-induced increase in bean leaf maintenance respiration  

Energy Technology Data Exchange (ETDEWEB)

Rates of respiration by unifoliate leaves of pinto bean (Phaseolus vulgaris) plants, exposed to low levels of ozone, were partitioned into growth and maintenance components using a popular model of plant respiration. The mode can be written as R/W = G/sub R/(dW/dt)/W + m, where R/W is the leaf specific respiration rate, (dW/dt)/W is the leaf specific growth rate, G/sub R/ is the growth coefficient, and m is the maintenance coefficient. In controlled environment growth chamber experiments, plants were treated with one of two levels of ozone: 90 parts per billion (p.p.b., i.e., nl liter/sup -1/), for 6 h d/sup -1/ (+ ozone), or less than 15 p.p.b. (-ozone). The growth coefficient was not affected by ozone. The maintenance coefficient, however, was 10-15% larger in leaves of plants from the + ozone treatment, compared to the-ozone treatment. This difference in the maintenance coefficient was statistically significant. Open-top field chamber experiments were also conducted. As in the growth chamber experiments, ozone dose did not affect the growth coefficient, but increases in ozone resulted in significant increases in the maintenance coefficient. The results of these experiments suggest that one reason ozone inhibits plant growth and productivity is that maintenance respiration increases, probably in order to repair injury.

Amthor, J.S.

1987-01-01

276

Stratospheric ozone  

Directory of Open Access Journals (Sweden)

Full Text Available Stratospheric ozone acquired a huge importance two decades ago because of the discovery of strong anomalies above the Antarctica due to gases of anthropogenic origin. From that date, stratosphere has become one of the research lines receiving more funding. A result, an important progress in the development of observational techniques, the understanding of the dynamics of the polar regions and, above all, in understanding of the chemical interactions among the species that influence the chemical-radiative balance of ozone. In this article a general revision is made of the distribution of the ozone in the stratosphere, the mechanisms that determine its equilibrium, the gases that contribute to its destruction, the present situation and the forecast of the health state of the layer.

M. Gil

2006-01-01

277

Ozone Pollution  

Medline Plus

Full Text Available ... Air Agencies U. S. Environmental Protection Agency sites: Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: ...

278

Ozone depletion zone and ozone smog. Ozone chemistry fundamentals  

International Nuclear Information System (INIS)

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.)

1994-01-01

279

Performance of pine sawflies under elevated tropospheric ozone.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Concentration of the phytotoxic air pollutant, ozone (O3) is continually increasing in the lower layer of the troposphere. The purpose of this study was to compare performance of pine sawflies on Scots pine seedlings in ambient and future levels of ozone. Scots pine seedlings were grown in field fumigation system where the ozone doses in fumigated plots were 1.5–1.6 times the ambient level. Larvae of the European pine sawfly (Neodiprion sertifer) and Gilpinia pallida were reared on the foli...

Lyytika?inen, Pa?ivi; Kainulainen, Pirjo; Nerg, Anne; Neuvonen, Seppo; Virtanen, Tarmo; Holopainen, Jarmo K.

1996-01-01

280

Ozone Pollution  

Medline Plus

Full Text Available ... Ethel Help Judy Fight for Healthier Air Outdoor Air Pollution Causes Cancer Deaths Smart links footer - Homepage Key ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

 
 
 
 
281

Ozone Pollution  

Medline Plus

Full Text Available ... Source. 2007 ; 6: 40. 3 . Medina-Ramón M, Schwartz J. Who is more vulnerable to die from ... 66: 217-222; Medina-Ramón M, Zanobetti A, Schwartz J. The Effect of Ozone and PM10 on ...

282

Ozone Pollution  

Medline Plus

Full Text Available ... F, Faustini A, Biggeri A, Bisanti L, et al. Susceptibility factors to ozone-related mortality: A population- ... 2009;109: 567-574. 8 . Thaller EI, et al., 2008. 9 . Bell ML, McDermott A, Zeger SL, ...

283

Ozone Depletion  

Science.gov (United States)

This three step Flash animation begins by showing how the layers of the atmosphere screen out harmful ultraviolet radiation. The electromagnetic spectrum is displayed and different types of radiation are shown emitted from different portions of the spectrum. The second and third stages show ozone formation and destruction respectively.

Hall, Prentice

284

Ozone Pollution  

Medline Plus

Full Text Available ... based case-crossover analysis. Am J Respir Crit Care Med . 2010; 182: 376-384; Jerrett M, Burnett RT, Pope CA III, Ito K, Thurston G, Krewski D, Shi Y, Calle E, Thun M. Long-term ozone exposure and mortality. N Engl J Med . ...

285

Ozone Pollution  

Medline Plus

Full Text Available ... enough ozone during the summer months to cause health problems that can be felt right away. Immediate problems—in addition to increased risk ... Childhood Respiratory Allergies in the United States. Environ Health Perspect. 2009; 117:140-147. 23 . U.S. EPA., ... right margin ad Mobile App Download the FREE State ...

286

Ozone Pollution  

Medline Plus

Full Text Available ... Thun M. Long-term ozone exposure and mortality. N Engl J Med . 2009;360: 1085-1095; Alexeeff ... Spain. Public Health . 2010; 124: 28-36; Middleton N, Yiallouros P, Kleanthous S, Kolokotroni O, Schwartz J, et ...

287

Ozone Pollution  

Medline Plus

Full Text Available ... displacement in the association of ozone with mortality: an analysis of 48 cities in the United States. Am J Respir Crit Care Med 2008; 177:184-189; Katsouyanni K, Samet JM, Anderson HR, Atkinson R, Le Tertre A, et al. ...

288

Ozone Pollution  

Medline Plus

Full Text Available ... much of the sun’s ultraviolet radiation. However, ozone air pollution at ground level where we can breathe it ( ... PJ, Chen L, Rowe BH, Coates F. Outdoor air pollution and emergency department visits for asthma among children ...

289

Ozone Pollution  

Medline Plus

Full Text Available ... 2007; 132: 1890-1897; McDonnell WF, Stewart PW, Smith MV. Prediction of ozone-induced lung function responses ... Action Press Materials Press Releases News Stories Blogs Web Banners Infographic Contact Information American Lung Association 1301 ...

290

Tropopause Ozone  

Science.gov (United States)

The tropopause, however defined, is meant to describe the boundary between the well mixed troposphere and the stably stratified stratosphere. Ozone abundances in the vicinity of the tropopause exhibit large variations with latitude and season, being controlled by a combination of large-scale transport like the Brewer-Dobson circulation, small-scale turbulent mixing unresolved by global models, and photochemistry. A clear, instantaneous, 3-D definition of the tropopause is needed for diagnostics that separate stratosphere from troposphere, e.g., strat-trop exchange fluxes. In the UCI CTM, we define the stratosphere-troposphere boundary with what is effectively an age-of-air tracer: a tracer emitted uniformly from the surface with a uniform e-fold of 90 days (designated e90). Where the abundance of e90 falls below about 70% of the mass-median value (i.e., 33 days-old), we define as the stratosphere. With this diagnostic of the mixing barrier between stratosphere and troposphere the CTM with EC IFS forecast meteorology is able to match much of the observed seasonal cycle of the tropopause pressure and ozone abundance. With the CTM we examine the importance of chemistry vs. transport in controlling tropopause ozone. For example, we note that photolysis of molecular oxygen in the upper troposphere contributes significantly to tropopause ozone in the tropics and sub-tropics.

Prather, M.; Zhu, X.; Hsu, J.; Neu, J.; Tang, Q.

2009-04-01

291

Ozone and aircraft operations  

Science.gov (United States)

The cabin ozone problem is discussed. Cabin ozone in terms of health effects, the characteristics of ozone encounters by aircraft, a brief history of studies to define the problem, corrective actions taken, and possible future courses of action are examined. It is suggested that such actions include avoiding high ozone concentrations by applying ozone forecasting in flight planning procedures.

Perkins, P. J.

1981-12-01

292

The Antarctic Ozone Hole  

Science.gov (United States)

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…

Jones, Anna E.

2008-01-01

293

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

International Nuclear Information System (INIS)

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 lifetime of many metal sulfide nanoparticles in the aquatic environment.

2011-01-01

294

PREDICTING THE REGIONAL IMPACT OF OZONE AND PRECIPITATION ON THE GROWTH OF LOBLOLLY PINE AND YELLOW-POPLAR USING LINKED TREGRO AND ZELIG MODELS  

Science.gov (United States)

To simulate the long-term effects of ozone on forests in the US, we linked TREGRO, a mechanistic model of an individual tree, to ZELIG, a forest stand model, to examine the response of forests to 5 ozone exposure regimes (0 to 100 ppm-hr SUM06 per year) in 100 year simulations. ...

295

Ozone tolerance of European larch (Larix decidua Mill.)  

International Nuclear Information System (INIS)

Larix decidua has been classified as a tree species ''highly sensitive'' to ozone. However, in Austria its main distribution is at altitudes where the recommended limits for ozone concentrations for sensitive plants are strongly exceeded for long periods. Long-term fumigation of twigs of a mature larch tree with ambient or double ambient air ozone concentrations did not cause any visible damage or negative influence on the gas exchange. However very high exposure of 1200 ppb ozone led to acute damage in long shoot needles with high gas exchange rates in the sun, but led only to small damages on shaded long shoots. Needles on short shoots neither developed visible damages nor were their capabilities for photosynthesis and stomatal regulation reduced, nor did they exhibit signs of premature senescence. According to the results of this investigation, European larch should be classified as ''intermediate'' or even as ''less sensitive'' to ozone. (orig.)

1993-04-01

296

EFFECTS OF INCREASING DOSES OF SULFUR DIOXIDE AND AMBIENT OZONE ON TOMATOES: PLANT GROWTH, LEAF INJURY, ELEMENTAL COMPOSITION, FRUIT YIELDS, AND QUALITY  

Science.gov (United States)

Jet star, an indeterminant tomato cultivar, was exposed to 0.011, 0.059, 0.118, 0.235, and 0.468 ppm SO2 in open-top field chambers supplied with nonfiltered(NF) air and to 0.005, 0.113, and 0.466 ppm SO2 in chambers with charcoal-filtered(CF) air. Treatments were given 5 hr/day,...

297

Monitoring of ozone in selected forest ecosystems in Southern Carpathian and Romanian Intensive Monitoring Network (level II).  

Science.gov (United States)

In the Romanian forest ecosystems, the first measurements of ambient ozone (O(3)) concentrations started in 1997 in 6 of 26 locations established in a trans-Carpathian Network. Furthermore, three additional ozone and other phytotoxic pollutant (NO(x), SO(2) and NH(3)) monitoring networks were installed in 2000 in Retezat (11 locations) and during 2006-2009 in Bucegi-Piatra Craiului (22 locations) LTER Sites. Since 2007, in four Intensive Forest Monitoring plots (level II), measurements of ozone concentrations were developed. Measurements were made using the Ogawa® passive sampler system during the growing season (April to October). In the Bucegi LTER Site, the seasonal means of 42.5-47.2 ppb in 2006 and 2008 were higher than those determined in the Carpathian Network in the 1997-1999 period (39.0-42.0 ppb), while the 2009 mean of 40.0 ppb was in the range of these values. The O(3) levels were slightly higher than those measured in Retezat LTER Site. In the Intensive Forest Monitoring Network (level II), no significant differences in ozone concentrations between individual core plots were noticed. The seasonal means for each plot range between 36.8 and 49.8 ppb in 2008. An influence of ozone concentrations on crown condition and tree volume growth was not determined. PMID:22531931

Silaghi, Diana; Badea, Ovidiu

2012-05-01

298

Ozone and Your Health  

Science.gov (United States)

... and Your Health Particle Pollution Public Health Issues Ozone and Your Health Breathing in ground-level ozone can be harmful to your health. How can ozone affect my health? If you have asthma, bronchitis, ...

299

EFFECT OF OZONE ON DIESEL EXHAUST PARTICLE TOXICITY  

Science.gov (United States)

Ambient particulate matter (PM) concentrations have been associated with mortality and morbidity. Diesel exhaust particles (DEP) are present in ambient urban air PM. Coexisting with DEP (and PM) is ozone (O(3)), which has the potential to react with some components of DEP. Some r...

300

A passive sampler for atmospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

A simple, cost-effective passive sampler has been developed for the determination of atmospheric ozone. This passive sampler is based on a colorant which fades upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Direct, on-site measurements are possible, and no chemical analyses are needed. Sampler design and validation studies have been carried out and included quantitative determination of color change vs exposure time (1-8 days), color change vs. ozone concentration (30-350 ppb), and response to changes in sampler configuration that modify the passive sampling rate. With indigo carmine as the colorant, the detection limits are 30 ppb. day and 120 ppb. day using a plastic grid and Teflon filter, respectively, as diffusion barriers. Interferences from nitrogen dioxide, formaldehyde and peroxyacetyl nitrate are 15, 4 and 16%, respectively, thus resulting in a negligible bias when measuring ozone in ambient air.

Grosjean, D.; Hisham, M.W.M. (DGA, Inc., Ventura, CA (United States))

1992-02-01

 
 
 
 
301

A passive sampler for atmospheric ozone  

International Nuclear Information System (INIS)

A simple, cost-effective passive sampler has been developed for the determination of atmospheric ozone. This passive sampler is based on a colorant which fades upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Direct, on-site measurements are possible, and no chemical analyses are needed. Sampler design and validation studies have been carried out and included quantitative determination of color change vs exposure time (1-8 days), color change vs. ozone concentration (30-350 ppb), and response to changes in sampler configuration that modify the passive sampling rate. With indigo carmine as the colorant, the detection limits are 30 ppb. day and 120 ppb. day using a plastic grid and Teflon filter, respectively, as diffusion barriers. Interferences from nitrogen dioxide, formaldehyde and peroxyacetyl nitrate are 15, 4 and 16%, respectively, thus resulting in a negligible bias when measuring ozone in ambient air

1992-01-01

302

Effect of foliage surface wetness on the deposition of ozone  

Energy Technology Data Exchange (ETDEWEB)

This study investigated the influence of foliage surface wetness on the deposition of ozone onto vegetation. Outdoor data, above and within a deciduous forest canopy, showed ozone deposition was affected by solar radiation, wind speed and ambient ozone concentration. Ozone deposition deep in the canopy was small compared to the upper canopy, because of the larger biological sink for ozone in the upper canopy. Substantial ozone deposition occurred while the forest canopy remained wet with either dew or rain water, nighttime and daytime. The ozone deposition onto hypostomatous red maple (Acer rubrum) and amphistomatous hybrid poplar (Populus deltoides tricocarpa) leaves was determined under controlled conditions. The ozone deposition onto wet maple leaves increased after water spraying. Nighttime measurements demonstrated that the enhanced deposition onto wet maple leaves was largely controlled by the chemistry of the solution on leaves. Small ozone deposition reductions were measured after poplar leaves became wet during daytime conditions. Little deposition was detected onto wet poplar leaves during the night, indicating that leaf water chemistry was less important as an ozone sink for poplar leaves. Water from poplar leaves offered little ozone sink whereas water from maple leaves was more effective in scavenging ozone. Data from outdoor and indoor experiments were incorporated in a one-dimensional model to further investigate the contribution of foliage wetness (dew) on the deposition of ozone onto vegetation. The model assumed that the deposition can be found from the ratio of the ozone concentration gradient and the sum of resistances to the transfer along the source-to-sink pathway. The modeled and measured deposition velocities compared reasonably well when the forest remained either dry or wet with dew. The indoor and outdoor studies demonstrate foliage wetness is an important factor in determining the ozone deposition to natural vegetated surfaces.

Fuentes, J.D.

1992-01-01

303

Ozone Pollution  

Medline Plus

Full Text Available ... EI, Petronell SA, Hochman D, Howard S, Chhikara RS, Brooks EG. Moderate Increases in Ambient PM 2.5 ... Environ Res. 2002; 89:29-37; Burnett RT, Brook JR, Yung WT, Dales RE, Krewski D. Association ...

304

Ozone Pollution  

Medline Plus

Full Text Available ... Air Agencies U. S. Environmental Protection Agency sites: Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: Act Locally What You Can Do News from ...

305

Ozone Pollution  

Medline Plus

Full Text Available ... city in the nation to install an air quality warning flag system on the beach. 8 How ... Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: Act Locally What You ...

306

Ozone Pollution  

Science.gov (United States)

... Level Air Pollution on Respiratory Health of Adults Suffering from Moderate to Severe Asthma. Environ Res. 2002; ... of ambient air pollution during early pregnancy on fetal ultrasonic measurements during mid-pregnancy. Environ Health Perspect . ...

307

Ozone Pollution  

Medline Plus

Full Text Available ... Level Air Pollution on Respiratory Health of Adults Suffering from Moderate to Severe Asthma. Environ Res. 2002; ... of ambient air pollution during early pregnancy on fetal ultrasonic measurements during mid-pregnancy. Environ Health Perspect . ...

308

Stratospheric ozone depletion  

Energy Technology Data Exchange (ETDEWEB)

This bulletin describes stratospheric ozone depletion as a set of environmental indicators designed to provide a profile of the state of Canada's environment. Causes and solutions to the problem of ozone depletion are outlined, including Canada's Ozone-Depleting Substances Regulations, 1998 and Canada's Federal Halocarbon Regulations applying to all federal facilities which went into effect in July 1999. Ozone depletion over the poles, causes, a possible link between stratospheric ozone loss and climate change, new supplies of ozone-depleting substances, global atmospheric concentrations of ozone-depleting substance and stratospheric ozone levels are described.

NONE

1999-07-01

309

Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters / Crescimento de Crassostrea gasar cultivada em ambientes marinho e estuarino em águas brasileiras  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi avaliar o crescimento da ostra-do-mangue Crassostrea gasar cultivada em ambiente marinho e estuarino. As ostras foram cultivadas por 11 meses em sistema de espinhel, em dois locais de estudo - São Francisco do Sul e Florianópolis -, em Santa Catarina. A concentração de [...] clorofila-?, a temperatura e a salinidade da água foram registradas semanalmente. As ostras foram medidas mensalmente (tamanho da concha e ganho de peso) para avaliar o crescimento. No final do período de cultivo, os pesos médios de carne úmida, carne seca e concha foram determinados, bem como a distribuição das ostras por classes de tamanho. Seis modelos não lineares (logístico, exponencial, Gompertz, Brody, Richards e Von Bertalanffy) foram ajustados aos dados de crescimento das ostras. As médias finais de tamanho da concha foram maiores em São Francisco do Sul do que em Florianópolis. Além disso, as ostras cultivadas em São Francisco do Sul apresentaram distribuição mais uniforme nas classes de tamanho do que aquelas cultivadas em Florianópolis. Os maiores valores médios de peso de carne úmida e peso de concha foram observados em São Francisco do Sul, enquanto o peso da carne seca não diferiu entre os locais. O ambiente estuarino é mais promissor para o cultivo de ostras. Abstract in english The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites - São Francisco do Sul and Florianópolis -, in the state of Santa Catarina, Southe [...] rn Brazil. Water chlorophyll-? concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy) were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters.

Gustavo Ruschel, Lopes; Carlos Henrique Araujo de Miranda, Gomes; Cláudio Rudolfo, Tureck; Claudio Manuel Rodrigues de, Melo.

310

Study on Variation of Lipids during Different Growth Phases of Living Cyanobacteria Using Easy Ambient Sonic-Spray Ionization Mass Spectrometry.  

Science.gov (United States)

Lipids are important components of cell membranes and thylakoids in cyanobacteria, and they play vital roles in various biological activities. Real-time tracing of the variation of membrane lipids can provide insights of the physiological status of cyanobacterial cells. In this work, easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was utilized to investigate the changes of acidic lipids in unicellular (Synechocystis 6803, Synechococcus 7002) and filamentous (Anabaena 7120) cyanobacteria during different growth phases. A sqdX mutant with a reduced synthesis of sulfoquinovosyl diacylglycerol (SQDG) was constructed to verify the acquired data of EASI-MS. Principal component analysis (PCA) was performed to compare the acquired data, enabling the discrimination of different species of cyanobacteria in day-to-day analysis. The results showed that the three representative cyanobacteria and their growth status can be easily determined on the basis of the lipids components detected by EASI-MS. Very interestingly, significant decreases of the ratios of SQDG/PG and dramatic changes of the unsaturation level of lipids were observed in different culture times in these cyanobacteria, and these two unique characters can be used describe the aging of cyanobacteria. PMID:24945367

Liu, Yiqun; Zhang, Jialing; Nie, Honggang; Dong, Chunxia; Li, Ze; Zheng, Zhenggao; Bai, Yu; Liu, Huwei; Zhao, Jindong

2014-07-15

311

Enxertia, produção e qualidade de tomateiros cultivados em ambiente protegido Grafting, production and quality of tomato growth in protected environment  

Directory of Open Access Journals (Sweden)

Full Text Available Com o objetivo de verificar os efeitos da enxertia na produção e qualidade de tomateiros cultivados em ambiente protegido, conduziu-se um experimento em Viçosa, Minas Gerais (MG. Seis tratamentos foram avaliados no delineamento em blocos casualizados, com três repetições, resultantes da combinação de duas cultivares de tomate 'Débora' e 'Sta. Clara', enxertadas sobre os porta-enxertos 'Anchor T' e 'BGH 3472', além das duas cultivares de pés francos. A enxertia foi realizada por encostia. Os tratamentos enxertados com 'BGH 3472' e os pés francos Débora e Sta. Clara apresentaram as maiores produtividades comerciais. Não houve variação no teor de SST dos frutos, e o pH da polpa dos frutos foi menor nas combinações 'Anchor T'/Sta. Clara e 'BGH 3472'/Débora. Observou-se maior ATT nos frutos de Débora e menor nos frutos de Sta. Clara. A relação SST/ATT foi maior nos frutos da combinação 'Anchor T'/Sta. Clara, comparados aos frutos das combinações 'BGH 3472'/Débora e 'Anchor T'/Débora.In order to check the effects of grafting in the production and quality of tomato grown in unheated greenhouse, an experiment was conducted in Viçosa, Minas Gerais State, Brazil. Six treatments were evaluated in randomized block design with three replications, resulting from the combination of two tomato cultivars Débora and Sta. Clara, grafted on two rootstocks 'Anchor T' and 'BGH 3472' in addition of the two ungrafted cultivars. The grafting method utilized was used. The treatments with the rootstock 'BGH 3472' and the cultivars 'Débora' and 'Sta. Clara' presented greatest commercial yields. There was no change in the content of SST. Fruit pH was smaller at the combinations 'Anchor T'/Sta.Clara and 'BGH 3472'/Débora Clara. It was observed greater ATT in the pulp of the fruits of Débora and smaller in the fruits of Sta. Clara. SST/ATT ratio was greater in fruits of the combination 'Anchor T'/Sta.Clara when compared with the fruits of the combinations between BGH 3472/Débora and BGH and 'Anchor T'/Débora.

Rodolfo Araujo Loos

2009-02-01

312

Enxertia, produção e qualidade de tomateiros cultivados em ambiente protegido / Grafting, production and quality of tomato growth in protected environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com o objetivo de verificar os efeitos da enxertia na produção e qualidade de tomateiros cultivados em ambiente protegido, conduziu-se um experimento em Viçosa, Minas Gerais (MG). Seis tratamentos foram avaliados no delineamento em blocos casualizados, com três repetições, resultantes da combinação [...] de duas cultivares de tomate 'Débora' e 'Sta. Clara', enxertadas sobre os porta-enxertos 'Anchor T' e 'BGH 3472', além das duas cultivares de pés francos. A enxertia foi realizada por encostia. Os tratamentos enxertados com 'BGH 3472' e os pés francos Débora e Sta. Clara apresentaram as maiores produtividades comerciais. Não houve variação no teor de SST dos frutos, e o pH da polpa dos frutos foi menor nas combinações 'Anchor T'/Sta. Clara e 'BGH 3472'/Débora. Observou-se maior ATT nos frutos de Débora e menor nos frutos de Sta. Clara. A relação SST/ATT foi maior nos frutos da combinação 'Anchor T'/Sta. Clara, comparados aos frutos das combinações 'BGH 3472'/Débora e 'Anchor T'/Débora. Abstract in english In order to check the effects of grafting in the production and quality of tomato grown in unheated greenhouse, an experiment was conducted in Viçosa, Minas Gerais State, Brazil. Six treatments were evaluated in randomized block design with three replications, resulting from the combination of two t [...] omato cultivars Débora and Sta. Clara, grafted on two rootstocks 'Anchor T' and 'BGH 3472' in addition of the two ungrafted cultivars. The grafting method utilized was used. The treatments with the rootstock 'BGH 3472' and the cultivars 'Débora' and 'Sta. Clara' presented greatest commercial yields. There was no change in the content of SST. Fruit pH was smaller at the combinations 'Anchor T'/Sta.Clara and 'BGH 3472'/Débora Clara. It was observed greater ATT in the pulp of the fruits of Débora and smaller in the fruits of Sta. Clara. SST/ATT ratio was greater in fruits of the combination 'Anchor T'/Sta.Clara when compared with the fruits of the combinations between BGH 3472/Débora and BGH and 'Anchor T'/Débora.

Loos, Rodolfo Araujo; Caliman, Fabiano Ricardo Brunele; Silva, Derly José Henriques da.

313

The crustal structure in north Tibet revealed by joint inversion of receiver functions and ambient noise tomography: implications for the growth of the Tibetan Plateau  

Science.gov (United States)

Northern Tibet is bounded by the Kunlun Fault in the north with the East Kunlun-Qaidam block. The conjunction region is at a nascent stage of plateau growth resulting from the collision between Indian and Eurasian plate starting ~50 million years ago, which is one of best areas to study the growth mechanism of the Tibetan Plateau. In this study, by investigating the crustal structure, we aim to address two questions: (1) whether the Tibetan plateau is growing northward and (2) if so, what is the growth mechanism, crustal shortening or channel flow. To construct the crustal velocity structures in northern Tibet and its surrounding regions, we analyze continuous ambient noise data collected from several seismic arrays, including the Northeast Tibet Seismic Experiment (NETS), A Seismic Collaborative Experiment in Northeastern Tibet (ASCENT) and Chinese provincial networks operating during 2007 and 2010, totaling ~280 stations and ~33 000 inter-station paths, and then generate Rayleigh phase velocity maps at 10-60 sec periods using ambient noise tomography. We also obtain receiver functions for each station from teleseismic events. A 3-D Vsv model is constructed from joint inversion of receiver functions and surface wave dispersion curves using a Bayesian Monte Carlo method. The large number of stations and high dense of ray path coverage adopted in our study results in a model with a lateral resolution reaching 50-100 km, which helps to reveal the detailed distribution of mid-crustal low velocity zones (LVZs). Our 3D model reveals strong LVZs at the middle crust between 20 and 40 km across northern Tibet with broad features similar to previous ambient noise tomography but with more details showing significant west-east variations of LVZs along the Kunlun Fault. In the west part, LVZs are confined to regions of the Kunlun Fault and the eastern Kunlun Mountain but do not appear beneath the Qaidam Basin; while in the east part beyond the east boundary of the Qaidam Basin, LVZs are observed to extend and penetrate northward into the East Kunlun and Qinling Orogens over ~100 km beyond the Kunlun Fault. The strong contrast of the distribution of LVZs in the west and east parts of the study region mainly results from the distinct tectonic units neighboring northern Tibet with a strong crust of the Qaidam Basin in the west blocking the penetration of LVZs but a probably weak crust in the Qinling Mountains allowing the flow of LVZs. Comparable mid-crustal LVZs are also observed in the northwest Qilian Orogen. There is no obvious connection between the LVZs beneath the Qilian Orogen and those in northern Tibet, which probably suggests different generation mechanisms and sources for LVZs. The distribution and extent of LVZs in our model provide new constraints in understanding and distinguishing the existing models of the Tibetan growth.

Jiang, C.; Yang, Y.; Zheng, Y.

2013-12-01

314

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

1984-01-01

315

Ambient surfactantless synthesis, growth mechanism, and size-dependent electrocatalytic behavior of high-quality, single crystalline palladium nanowires.  

Science.gov (United States)

In this report, we utilize the U-tube double diffusion device as a reliable, environmentally friendly method for the size-controlled synthesis of high-quality, single crystalline Pd nanowires. The nanowires grown in 200 and 15 nm polycarbonate template pores maintain diameters of 270 ± 45 nm and 45 ± 9 nm, respectively, and could be isolated either as individual nanowires or as ordered free-standing arrays. The growth mechanism of these nanowires has been extensively explored, and we have carried out characterization of the isolated nanowires, free-standing nanowire arrays, and cross sections of the filled template in order to determine that a unique two-step growth process predominates within the template pores. Moreover, as-prepared submicrometer and nanosized wires were studied by comparison with ultrathin 2 nm Pd nanowires in order to elucidate the size-dependent trend in oxygen reduction reaction (ORR) electrocatalysis. Subsequently, the desired platinum monolayer overcoating was reliably deposited onto the surface of the Pd nanowires by Cu underpotential deposition (UPD) followed by galvanic displacement of the Cu adatoms. The specific and platinum mass activity of the core-shell catalysts was found to increase from 0.40 mA/cm(2) and 1.01 A/mg to 0.74 mA/cm(2) and 1.74 A/mg as the diameter was decreased from the submicrometer size regime to the ultrathin nanometer range. PMID:21875051

Koenigsmann, Christopher; Santulli, Alexander C; Sutter, Eli; Wong, Stanislaus S

2011-09-27

316

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

International Nuclear Information System (INIS)

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

1991-09-16

317

EFFECT OF AN OZONE INJURY RETARDANT CHEMICAL ON ISOZYME PROFILES FROM ALFALFA CALLUS IN VITRO  

Science.gov (United States)

Plant ozone injury retardant (EDU or ethylenediurea) at 1.0 ppm inhibited growth of callus of alfalfa cultivars Williamsburg (ozone-sensitive) and MSB-CW5An2(ozone-insensitive) germplasm of Medicago sative. The presence of EDU(0.1 ppm) in growth medium increased the number of pro...

318

Salud y medio ambiente: Health and environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Motivado por la importancia del control del medio ambiente se realiza un panel con los estudiantes de la especialidad de Tecnología de la Salud en el municipio de Matanzas, con el objetivo de fomentar en estos una conciencia ambientalista y de esta forma sensibilizar a los mismos, para ser defensore [...] s en la protección del medio ambiente y así elevar el conocimiento en cuanto a materia ambiental. Desde el triunfo revolucionario en 1959, la protección del medio ambiente y el uso racional de los recursos naturales ha sido objetivo estratégico nacional. Y en medio de la difícil situación económica actual, los esfuerzos por encausar la recuperación económica y la protección ambiental con un enfoque integral, constituyen un importante desafío para los cubanos. La contaminación de ríos y arroyos por contaminantes químicos se ha convertido en uno de los problemas ambientales más graves de nuestra sociedad. El ozono es un contaminante que produce afectaciones a la salud. La explotación forestal debe ser realizada sobre la base de garantizar la repoblación. Son diversos los factores que determinan el crecimiento elevado de la población en los países subdesarrollados. La concentración de la población, la industria y el transporte automotor en zonas urbanas ha producido un desequilibrio ecológico con grave afectación a la higiene del ambiente. Cuba, a pesar de ser un país subdesarrollado, el crecimiento económico y la industrialización han llevado aparejadas medidas consecuentes para la protección del ambiente y el desarrollo sostenible. Los riesgos como consecuencia de los fenómenos naturales o provocados por las actividades humanas están íntimamente relacionados con la naturaleza de los mismos. En todos los casos se hacen necesario priorizar los servicios de saneamiento básico esenciales para garantizar la salud de la población . Abstract in english Due to the importance of the environmental control, we carried out a debate with the students of the specialty of Health Technologies in the municipality of Matanzas with the objective of forming an environmental awareness and inducing them to be defenders of the environmental protection, and also r [...] aising their knowledge on the environmental matters. Since the triumph of the Cuban revolution in 1959, environmental protection and rational use of the natural resources have been a national strategic objective. Inserted in the current difficult economic situation, the efforts for achieving the economic recuperation and environmental protection through an integral approach are an important challenge for Cubans. Rivers and brooks contamination by chemical substances has become one of the most serious environmental problems in our society. Ozone is a contaminant producing health affections. Forestal exploitation should be carried on the bases of warranting repopulation. Several factors determine a high growth of population in the underdeveloped countries. The concentration of population, industries and auto transport in urban areas has produced an ecological disequilibrium with serious damage of the environmental hygiene. Although Cuba is an underdeveloped country, the economic growth and industrialization have been led together with tenacious measures to protect the environment and a sustainable development. Risks due to natural phenomena or caused by human activity are tightly related with their nature. In all the cases it is necessary to pay an especial attention to the services and measures guarantying the population health.

Jesús, Méndez Martínez; Arelis, Alberto Palenzuela; Ernesto, Morales Santana.

319

Ozonation reduces sludge production and improves denitrification.  

Science.gov (United States)

The effectiveness of partial ozonation of return activated sludge for enhancing denitrification and waste sludge minimization were examined. A pair of nitrifying sequencing batch reactors was operated in either aerobic or alternating anoxic/aerobic conditions, with one control and one ozonated reactor in each set. The amount of solids produced decreased with the ozone dose. Biomass in the anoxic/aerobic reactor was easier to destroy (up to 25% of the initial excess sludge) than in the aerobic (10%) one, generating approximately twice as much soluble COD by cell lysis. Denitrification rate improved up to 60% due to additional carbon released by ozonation. Nitrification rates deteriorated much more in the aerobic than in the alternating reactor, possibly as a result of direct destruction of nitrifying autotrophs as well as competition created by growth of heterotrophs receiving the additional COD. Overall, ozonation provided the expected benefits in denitrification and had less impact on nitrification in the alternating reactors. PMID:17188735

Dytczak, Magdalena A; Londry, Kathleen L; Siegrist, Hansruedi; Oleszkiewicz, Jan A

2007-02-01

320

A versatile low-pressure ozone source  

International Nuclear Information System (INIS)

A low-pressure source for pure ozone has been developed and successfully tested in the growth of oxide superconductor thin films. Ozone is selectively adsorbed on silica gel at a temperature of -77 degree C from an O3/O2 gas mixture stream containing 8 wt% O3, produced by a commercial ozone generator. Since only O3 is trapped, no further purification steps are required. Ozone/gel loading factors below 10% (wt/wt) ensure the safe storage of O3 over prolonged periods. Pure O3 is extracted from the silica gel trap, in which the O3 vapor pressure is maintained at around 10 mTorr, by applying a dynamic vacuum. Films of Ba2YCu3O7-? with Tc above 86 K have been grown in situ by molecular beam epitaxy techniques using this ozone source

1991-01-01

 
 
 
 
321

Impacts of ozone on trees and crops; Impacts de l'ozone sur les arbres et les recoltes  

Energy Technology Data Exchange (ETDEWEB)

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

Felzer, B.S.; Cronina, T.; Melillo, J.M. [The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA (United States); Reilly, J.M.; Xiaodong, Wang [Joint Program on the Science and Policy of Global Change, Massachusetts Institute of Technology, Cambridge, MA (United States)

2007-10-15

322

Secondary maxima in ozone profiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone profiles from balloon soundings as well as SAGEII ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is connected t...

Lemoine, R.

2004-01-01

323

Secondary maxima in ozone profiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 secondary maxima is related to...

Lemoine, R.

2004-01-01

324

Group 11 - Ozone Layer  

Science.gov (United States)

BACKGROUND Investigate the issues of the ozone layer. TASK - What is the ozone layer and where is it found? What is happening to it? What is causing that? Where is the hole located? What is ozones chemical make up? Who is currently studying this? Where? What has already been done to preserve the ozone layer? ...

Mecham, Mrs.

2006-11-30

325

The pathobiology of ozone-induced damage.  

Science.gov (United States)

Ozone remains one of the three most important air pollutants worldwide, yet little direct documented evidence of its genotoxicity exists. The interest in the pathology of ozone exposure and the molecular events that underlie its course stems from DNA damage caused by oxygen stress including hydroxyl radicals, superoxide, singlet oxygen, and hydrogen peroxide. Although the tissue damage associated with ozone inhalation occurs at both the conducting airway and the alveolus, the cellular and mechanistic processes underlying these events are less well understood. Ozone leads to the oxidative decomposition of polyunsaturated fatty acids. Ozone also depresses DNA replication in V79 Chinese hamster lung fibroblasts in a dose-dependent fashion (concentration, 1-10 ppm), which indicates that ozone or its reaction products may interact directly with DNA and inhibit replication. Ozone also linearizes circular DNA and induces ozone-sensitive mutant and pneumocytes to repair its DNA. DNA adducts have been implicated in aging, cellular transformation, mutagenesis, carcinogenesis, and cell death; DNA adducts are products of free radical damage. These events are all common in ozone exposure. Finally, DNA-binding proteins are potent positive and negative regulators, enhancers, or silencers of gene expression. Part of their action may be related to their ability to initiate the binding sequence of DNA transcription proteins and thus form complexes. Alteration of DNA-binding sites by ozone adducts may effect mRNA transcription due to altered binding by DNA-binding proteins. This altered transcription has been shown to effect growth factors involved in collagen and matrix regulation. The present review will address some of the complexities involved in ozone exposure.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2185706

Steinberg, J J; Gleeson, J L; Gil, D

1990-01-01

326

Secondary maxima in ozone profiles  

Directory of Open Access Journals (Sweden)

Full Text Available Ozone profiles from balloon soundings as well as SAGEII ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is connected to ozone variability and trend at Uccle and account for a large part of the total ozone and lower stratospheric ozone variability.

R. Lemoine

2004-01-01

327

Observations of ozone formation in power plant plumes and implications for ozone control strategies  

Energy Technology Data Exchange (ETDEWEB)

Data taken in aircraft transects of emissions plumes from rural US coal-fired power plants were used to confirm and quantify the nonlinear dependence of tropospheric ozone formation on plume NOx (NO plus NO{sub 2}) concentration, which is determined by plant NOx emission rate and atmospheric dispersion. The ambient availability of reactive volatile organic compounds, principally biogenic isoprene, was also found to modular ozone production rate and yield in these rural plumes. Differences of a factor of 2 or greater in plume ozone formation rates and yields as a function of NOx and volatile organic compound concentrations were consistently observed. These large differences suggest that consideration of power plant NOx emission rates and geographic locations in current and future US ozone control strategies could substantially enhance the efficacy of NOx reductions from these sources. 18 refs., 4 figs.

Ryerson, T.B.; Trainer, M.; Holloway, J.S.; Parrish, D.D.; Huey, L.G.; Sueper, D.T.; Frost, G.J.; Donnelly, S.G.; Schauffler, S.; Atlas, E.L.; Kuster, W.C.; Goldan, P.D.; Huebler, G.; Meagher, J.F.; Fehsenfeld, F.C. [NOAA, Boulder, CO (USA). Aeronomy Lab.

2001-04-27

328

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

Directory of Open Access Journals (Sweden)

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.

Janaina Paulino

2011-01-01

329

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

Energy Technology Data Exchange (ETDEWEB)

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)

2009-07-01

330

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

Energy Technology Data Exchange (ETDEWEB)

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)

2011-06-15

331

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

Energy Technology Data Exchange (ETDEWEB)

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)

2010-03-15

332

Effect of an ozone injury-retardant chemical on isozyme profiles from alfalfa callus in vitro  

Energy Technology Data Exchange (ETDEWEB)

Plant ozone injury retardant (EDU or ethylenediurea) at 1.0 ppm inhibited growth of callus of alfalfa cultivars Williamsburg (ozone-sensitive) and MSB-CW5An2(ozone-insensitive) germplasm of Medicago sative. The presence of EDU(0.1 ppm) in growth medium increased the number of protein and peroxidase isozyme bands in alfalfa cultivar stem callus and ozone modified their intensities. Protein profiles of MSB stem callus from media containing EDU or exposed to ozone were unchanged. Marked differences were observed between the peroxidase profiles of ozonated and control ozone-insensitive stem callus from media containing EDU. Protein profiles of ozonated ozone-insensitive leaf callus differed slightly from controls.

Rier, J.P.; Sood, V.K.; Whitaker, A.; Watson, C.

1983-01-01

333

Chlorofluorocarbons and environmental conservation of ozone layer; Furon to ozon so kankyo  

Energy Technology Data Exchange (ETDEWEB)

Effect of ozone depletion on environment caused by chlorofluorocarbons, its present situation, problems and future are discussed. Ozone layer protects the livings of the earth shading the ultraviolet rays of sun, warms up the earth by absorbing the ultraviolet rays from the sun and makes raise the atmospheric temperature by absorbing the infrared rays from the earth. This ozone layer which plays an important role in the atmosphere is getting depleted by chlorofluorocarbons that are now widely used as air conditioning, refrigerants of refrigerators, cleaning solvents, heat resistant materials and so forth. The chemical process related to the depletion of ozone layer are ozone formation reaction, ozone depletion chain reaction, reaction related to aerosols and so forth, and total ozone distribution observed from satellite sensor data is calculated. Increase in harmful ultraviolet rays caused by the depletion of ozone layer causes harm to human health such as increase in skin cancer, increase in cataract and so on, and also causes damage to plant growth and so forth. Besides, global warming is thought to be caused by the depletion of ozone layer, and it is the situation for thinking about alternative energy for chlorofluorocarbons. 13 refs., 8 figs., 3 tabs.

Nakane, H. [National Inst. for Environmental Studies, Tsukuba (Japan)

1994-09-01

334

Procedures for estimating the frequency of commercial airline flights encountering high cabin ozone levels  

Science.gov (United States)

Three analytical problems in estimating the frequency at which commercial airline flights will encounter high cabin ozone levels are formulated and solved: namely, estimating flight-segment mean levels, estimating maximum-per-flight levels, and estimating the maximum average level over a specified flight interval. For each problem, solution procedures are given for different levels of input information - from complete cabin ozone data, which provides a direct solution, to limited ozone information, such as ambient ozone means and standard deviations, with which several assumptions are necessary to obtain the required estimates. Each procedure is illustrated by an example case calculation that uses simultaneous cabin and ambient ozone data obtained by the NASA Global Atmospheric Sampling Program. Critical assumptions are discussed and evaluated, and the several solutions for each problem are compared. Example calculations are also performed to illustrate how variations in lattitude, altitude, season, retention ratio, flight duration, and cabin ozone limits affect the estimated probabilities.

Holdeman, J. D.

1979-01-01

335

On the impact of temperature on tropospheric ozone concentration levels in urban environments  

Science.gov (United States)

The influence of temperature on tropospheric ozone (O3) concentrations in urban and photochemically polluted areas in the greater Athens region are investigated in the present study. Hourly values of the ambient air temperature used for studying the urban heat island effect in Athens were recorded at twenty-three experimental stations while ozone concentration values were measured at three of the above-mentioned stations and for a period of two years (1996-1997). The linear correlation between ozone concentration and air temperature values as well as the temporal variation of temperature and ozone concentration, for the above-mentioned experimental stations, were calculated and analysed. Moreover, a neural network approach was used for investigating the impact of temperature on the ozone concentration values over the greater Athens area. The neural network model used ambient air temperature as one of its input parameters and it was found that temperature is a predominant parameter, affecting considerably the ozone concentration values.

Stathopoulou, E.; Mihalakakou, G.; Santamouris, M.; Bagiorgas, H. S.

2008-06-01

336

The Antarctic ozone hole  

International Nuclear Information System (INIS)

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

2008-07-01

337

Ozone and the Atmosphere  

Science.gov (United States)

This web site, hosted by NASA, discusses the chemical composition and evolution of Earth's atmosphere, focusing on the protective layer of ozone in the stratosphere. The destructive properties of tropospheric ozone are also presented. Diagrams and animation sequences are used to visually depict the delicate structure of the ozone molecule and the chemical reactions involved in its formation and destruction. Ozone destroying pollutants were first identified in 1973. Since that time there has been a considerable amount of controversy surrounding the subject of ozone depletion. More than 20 years of ozone-related scientific studies, international meetings, and global industrial agreements are summarized in the last section of this site.

Center, Distributed A.; Nasa

338

Antarctic ozone depletion  

International Nuclear Information System (INIS)

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

1993-05-20

339

Stratospheric ozone depletion  

International Nuclear Information System (INIS)

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)

2002-01-01

340

Measurement of Ozone Precursor Volatile Organic Compounds (VOCs)  

Energy Technology Data Exchange (ETDEWEB)

Proceedings of the International Expert Meeting. A number of international experts were invited to present the state-of-the-art of specific aspects of the measurement of ozone precursor volatile organic compounds, such as adsorptive and canister sampling, thermal desorption, hydrocarbon analysis by gas chromatography, formaldehyde analysis by liquid chromatography, (inter)calibration, quality assurance, and measurement networks. Individual expert contributions are presented in part 2 of this report: Analytical Methods and QA/QC for Ozone Precursor VOCs. Part 1 comprises Introduction, Summary and Conclusions of the Expert Meeting/workshop. Part 3 is about Monitoring Networks for Ozone Precursor VOCs and Part 4 are papers on Methods and Concentration levels of Ozone Precursor VOCs in European Countries. Part 5 contains the Annex, including the minutes and the text of the Directive 2002/3/EC of the European Parliament and of the Council of 12 February 2002 relating to ozone in ambient air.

Larsen, B.R. (ed.)

2004-07-01

 
 
 
 
341

Effects of acid fog and ozone on conifers. Final report  

Energy Technology Data Exchange (ETDEWEB)

This study evaluated the effects of acidic fog (pH 2.0, 3.0, or 4.0) on the physiological, biochemical, and growth responses of two coniferous tree species (Pinus ponderosa and Abies concolor), and determined if exposure to acidic fog predisposed the tree seedlings to the phytotoxic effects of ozone (O{sub 3}). Results provide evidence that the growth and metabolic responses of two coniferous tree species could be altered by multiple applications of acidic fog, and by exposure to ambient O{sub 3}. In general, the alterations were slight to modest, which may be attributed to the low degree of stress severity, and the slow rate of tree growth. The findings indicate that exposure to acidic fog followed by O{sub 3} does not cause detectable changes in conifer seedling growth within a single-growing season. Nevertheless, it is clear that acidic fog and O{sub 3} cause temporal alterations in seedling physiology and biochemistry.

Bytnerowicz, A.; Olszyk, D.M.; Takemoto, B.K.; McCool, P.M.; Musselman, R.C.

1989-05-01

342

Long term ozone trends in the Lake Michigan airshed  

Energy Technology Data Exchange (ETDEWEB)

Emissions-related improvements in ambient ozone are difficult to detect, because ozone changes are dominated by short-term variations due to meteorological fluctuations. Rao and Zurbenko (RZ) have developed a statistical filtering method to separate a time-series of ozone air quality data into its short-term, seasonal, and long-term components. The resulting long-term ozone trend has most meteorological influences removed and thus can reasonably be attributed to emissions changes. In this paper, the authors use the RZ method to derive long-term, emissions-related ozone trends from data collected at five ozone monitoring sites near Lake Michigan. They compare trends in peak daily 8-hour averages of ozone to trends in peak daily 1-hour averages, for the period 1980--95. Temperature is employed as a surrogate for all meteorological influences on ozone. Ozone data for these sites are available only for the monitoring period April 15 to October 15 each year. The results indicate that three sites have statistically significant trends, averaging an annual reduction of 1.12% for 8-hour ozone averages. The 1-hour trends for these sites averaged an annual reduction of 1.07%. The two remaining sites indicated a trend in both 1- and 8-hour ozone averages that was either marginal or not statistically significant. These results are comparable with RZ-derived ozone trends for Lake Michigan shoreline sites as calculated by others. However, the available 6-month data sets used here did not allow a complete verification of the RZ method for these sites because plots and correlations could not be compared with its theoretical assumptions which are based on year-round data sets.

Smith, B.E.; Adamski, W.J. [Wisconsin Dept. of Natural Resources, Madison, WI (United States). Bureau of Air Management

1997-12-31

343

An assessment of ground-level ozone concentrations in the Athabasca oil sands region  

International Nuclear Information System (INIS)

Syncrude and Suncor have plans to develop new oil sands leases and to increase crude oil and bitumen recovery in the Athabasca oil sands region. A first air quality assessment was prepared as part of the Alberta Energy and Utilities Board application, in order to evaluate the emissions and potential impacts associated with the development. The Pembina Institute raised several issues with respect to potential future changes in ambient ozone levels as a result of the Aurora Mine operations. In response to these concerns, another more rigorous assessment was conducted to predict future ground-level ozone concentrations in the Fort McMurray area. This report includes: (1) ambient air quality guidelines for ozone, (2) emissions inventory for dispersion modelling, (3) dispersion modelling methodology, and (4) predicted ambient ozone concentrations. Ground level ozone (O3) concentrations result from anthropogenically produced ozone, and from naturally occurring ozone. Ozone is not directly emitted to the atmosphere from industrial sources, but is formed as a result of chemical reactions between NOx and VOCs, which are emitted from industrial sources within the Athabasca oil sands region. NOx and VOC emissions associated with the Aurora Mine operation are predicted to increase hourly average ozone concentrations in the Fort McMurray area by only 0.001 ppm. 17 refs., 18 tabs., 5 figs

1997-01-01

344

An assessment of ground-level ozone concentrations in the Athabasca oil sands region  

Energy Technology Data Exchange (ETDEWEB)

Syncrude and Suncor have plans to develop new oil sands leases and to increase crude oil and bitumen recovery in the Athabasca oil sands region. A first air quality assessment was prepared as part of the Alberta Energy and Utilities Board application, in order to evaluate the emissions and potential impacts associated with the development. The Pembina Institute raised several issues with respect to potential future changes in ambient ozone levels as a result of the Aurora Mine operations. In response to these concerns, another more rigorous assessment was conducted to predict future ground-level ozone concentrations in the Fort McMurray area. This report includes: (1) ambient air quality guidelines for ozone, (2) emissions inventory for dispersion modelling, (3) dispersion modelling methodology, and (4) predicted ambient ozone concentrations. Ground level ozone (O{sub 3}) concentrations result from anthropogenically produced ozone, and from naturally occurring ozone. Ozone is not directly emitted to the atmosphere from industrial sources, but is formed as a result of chemical reactions between NO{sub x} and VOCs, which are emitted from industrial sources within the Athabasca oil sands region. NO{sub x} and VOC emissions associated with the Aurora Mine operation are predicted to increase hourly average ozone concentrations in the Fort McMurray area by only 0.001 ppm. 17 refs., 18 tabs., 5 figs.

NONE

1997-01-01

345

Probing stratospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

This paper is a review of research and present knowledge on ozone layer losses during the winter in the Arctic and Antarctic. Heterogeneous chemical reactions in polar stratospheric clouds and sulfate aerosols are discussed. Methods for determining actual ozone losses are discussed, with particular emphasis on the Arctic ozone layer.

Rodriguez, J.M. (Atmospheric and Environmental Research Inc., Cambridge, MA (United States))

1993-08-27

346

Beneficial effects of CO2 enrichment to field-grown soybeans under ozone stress  

International Nuclear Information System (INIS)

Damage from gaseous air pollution [e.g. ozone (O3) and sulfur dioxide (SO2)] on crops in the US has been estimated to exceed several billion dollars annually. Atmospheric carbon dioxide (CO2) concentrations have increased from about 290 ppm in the late 1800's to current levels of 350 ppm. The combined effects of increased CO2 and O3 stress have not been studied under field conditions. The present study was conducted to determine the interactive effects of CO2 enrichment and O3 stress on the growth and physiology of 'Clark' soybean, testing the hypothesis that elevated CO2 will ameliorate the effects of O3 stress. Experiments with soybeans in open-top field chambers showed that increasing CO2levels to 400 parts per million (ppm) negated current ambient ozone harmful effects on soybean yields. When ambient O3 levels were doubled, it was necessary to increase the atmospheric CO2 concentration to 500 ppm to negate O3 damage. Rising CO2 counteracts O3 pollution. Reduced stomatal conductance and decreased photosynthesis appear to reverse the CO2 stimulation

1991-05-01

347

The origin of ozone  

Directory of Open Access Journals (Sweden)

Full Text Available Highest atmospheric ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson circulation. This is considered the main mechanism to generate mid- and high latitude ozone. By applying the climate-chemistry models E39/C and MAECHAM4/CHEM, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analysed, by incorporating a diagnostics ('marked ozone origin tracers' into the models, which allows to identify the origin of ozone. In most regions the simulated local ozone concentration is dominated by local ozone production, i.e. less than 50% of the ozone at higher latitudes of the stratosphere is produced in the tropics, which conflicts with the idea that the tropics are the global source for stratospheric ozone. Although episodic stratospheric intrusions occur basically everywhere, the main ozone stratosphere-to-troposphere exchange is connected to exchange processes at the sub-tropical jet-stream. The simulated tropospheric influx of ozone amounts to 420 Tg per year, and originates in the Northern Hemisphere from the extra-tropical stratosphere, whereas in the Southern Hemisphere a re-circulation of tropical tropospheric ozone contributes most to the influx of ozone into the troposphere. In the model E39/C, the upper troposphere of both hemispheres is clearly dominated by tropical tropospheric ozone (40%–50% except for northern summer hemisphere, where the tropospheric contribution (from the tropics as well as from the Northern Hemisphere does not exceed 20%.

V. Grewe

2006-01-01

348

Responses of Tree Seedlings to a Changing Atmosphere: Effects of Carbon Dioxide, Nitrogen Dioxide, and Ozone  

Science.gov (United States)

Human activities have caused changes in the chemical composition of the atmosphere: the concentrations of carbon dioxide (CO2), nitrogen dioxide (NO2), and ozone (O3) have increased and are expected to continue increasing in the future. These gases have the potential to alter plant physiological processes, change growth rates, C:N, and carbon storage potential. The responses of tree seedlings to these changes will have a profound impact on the species composition and carbon storage potential of forests in the future. Others have found CO2 tends to increase plant growth and O3 to decrease it. NO2, if assimilated by plants, can be a source of nutrient nitrogen, but is also an oxidant with the potential to damage cell membranes and decrease growth. The objectives of this study were to determine the single and combined effects of CO2, NO2, and O3 on sugar maple, eastern hemlock, and two clones of trembling aspen. The trees were fumigated for two growing seasons with elevated (40ppb) or ambient NO2, elevated (560ppm) or ambient CO2, elevated (100 ppb 5 days/week) or ambient O3, and with or without additional soil nitrate (30 kg ha-1 yr-1) to simulate ecosystems with and without nitrogen limitation. We found that elevated CO2 increased total biomass of both maples and hemlocks. Further, the CO2 growth effect was most striking when combined with elevated O2; elevated CO2 eliminated the growth decrease induced by O3 especially when nitrogen was limited. Elevated NO2 had no effect on maple seedlings, but, similar to CO2, eliminated the decrease in growth under O3 on hemlock seedlings. The two aspen clones differed in their resistance to ozone. The non-resistant clone exhibited growth responses similar to maple. However, the resistant clone did not exhibit a growth response under any gas treatment regardless of soil nitrogen status. The variation in responses among species, within clones of the same species, and between fumigations was large in this study and suggests species level responses and exposure trials to combined gases will be necessary to parameterize future forest production models.

Eller, A. S.; Sparks, J. P.

2008-12-01

349

Overview of ozone bleaching  

Energy Technology Data Exchange (ETDEWEB)

The potential impact of the pulp and paper industry on the environment may be reduced by replacing chlorine-based bleaching reagents with ozone. The reactivity of ozone coupled with the heterogeneity of pulp allows many types of reactions to occur during pulp bleaching. Ozone cleaves the aromatic rings and side chain double bonds in lignin in Criegee-type mechanisms. Activated carbon-hydrogen bonds are fragmented in lignin side chains, as well as Cl carbons of {beta}-glycosides, by way of a 1,3 dipolar insertion forming a hydrotrioxide intermediate. Ozone also attacks carbohydrates at acetal oxygens, depolymerizing at the glycosidic bond. Unsaturated sites are ozonated before aliphatic sites resulting in a predominance of lignin reactions over carbohydrate reactions until lignin is substantially removed from the pulp. Important factors in the successful application of ozone bleaching include minimizing ozone decomposition and other secondary reactions, reducing exposure of cellulose to high concentrations of ozone and radicals, and promoting uniform exposure of ozone to lignin. The quantity of chlorinated organic compounds in effluents can be drastically reduced by replacing chlorine-based bleaching reagents with ozone; less organochlorine is formed and there can be greater recycle of bleach plant wastes back to the recovery cycle. Recycling of bleach plant waste also reduces total organic loading in the effluent. The toxicity of ozone filtrates is variable compared to conventional filtrates and depends on several parameters including bleaching conditions, biological treatment, and target organisms.

Sonnenberg, L.B. [Institute of Paper Science and Technology, Atlanta, GA (United States)

1995-12-31

350

Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes  

Directory of Open Access Journals (Sweden)

Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based on ozone concentration with others based on ozone flux models.

Gerardo Merola

2011-02-01

351

Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes  

Directory of Open Access Journals (Sweden)

Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based on ozone concentration with others based on ozone flux models.

Massimo Fagnano

352

Ozone studies in the Paso del Norte region  

Science.gov (United States)

The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results obtained from this photolysis study demonstrate that the local ground level ozone formation is not only influenced by the strong solar radiation and changing aerosol makeup, but also by other heterogeneous factors and reactions. In addition, this research provided good evidence that the ground level ozone precursor regime in El Paso during the ozone episode of June 2006 was mostly VOC-limited. Much of this estimation was derived from measurements of local ambient VOC/NOx ratios. This finding shows that at least during June 2006, the non-linear surface ozone production increased during weekends compared to workdays in a habitually VOC-limited regime. The seasonal variations of columnar ozone as measured by a Multi-filter Rotating Shadowband instrument installed at the UTEP campus are analyzed for the first time for this region and results are presented. This investigation has addressed the problem of ground-level ozone formation in the Paso del Norte region. Urban ozone is a complex problem with many aspects that are not fully understood. In this investigation, a range of techniques has been used to address the study of local surface ozone episodes with the purpose of acquiring new insights and knowledge that will help understand and remediate the diverse atmospheric pollution events that affect this bi-national region recurrently. Innovative techniques were developed and used, ranging from the use of local ambient atmospheric pollution data to the utilization of complex modeling techniques to achieve the best possible computer results. Finally, the influence of ground level ozone concentrations in admissions to hospitals for this region due to respiratory diseases is analyzed. The comprehensive results obtained in this work will help to better understand ozone formation in the Paso del Norte Region for future policy regulation implementations.

Becerra-Davila, Fernando

353

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

International Nuclear Information System (INIS)

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

2013-03-01

354

Influenza virus infection, ozone exposure, and fibrogenesis  

Energy Technology Data Exchange (ETDEWEB)

Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage.

Jakab, G.J.; Bassett, D.J. (Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (USA))

1990-05-01

355

Ethylenediurea (EDU): A research tool for assessment and verification of the effects of ground level ozone on plants under natural conditions  

International Nuclear Information System (INIS)

Ethylenediurea (EDU) has been widely used to prevent ozone (O3) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O3 and in the presence of O3 before initiating multiple applications to prevent O3 injury. EDU can be used to verify foliar O3 symptoms in the field, and to screen plants for sensitivity to O3 under ambient conditions. Despite considerable research, the mode of action of EDU remains elusive. Additional research on the mode of action of EDU in suppressing O3 injury in plants may also be helpful in understanding the mode of action of O3 in causing injury in plants. - EDU is a verified and effective tool for the assessment of the effects of ozone on plants.

2011-12-01

356

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

DEFF Research Database (Denmark)

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 concentration. The experiment was conducted during 70 days during the autumn. Our system could not detect any ozone effects on dark respiration, but eventually effects on dark respiration could be masked in signal noise. An inhibition of daily net photosynthesis in ozone treated shoots was apparent, and it is 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.

Mikkelsen, Teis Nørgaard

2002-01-01

357

Effects of ozone and sulfur dioxide on soybeans  

Energy Technology Data Exchange (ETDEWEB)

Ambient ozone concentrations at three rural upper-midwestern sites were characterized based upon four years of continuous monitoring. Examination of annual and diurnal fluctuations and individual events revealed a relationship between ozone and temperature, solar radiation, oxides of nitrogen, and stratospheric incursion. Ambient sulfur dioxide concentrations near a large point source in central Minnesota were characterized based upon four years of monitoring during the summer months. Fumigation events were rare, and the concentrations during the events were low. The mean annual concentration of sulfur dioxide was approximately 0.4 ppB. Soybeans were grown in ambient plots and in open-top field chambers which were either filtered or unfiltered to remove pollutants from the incoming air. The results indicated that the programmed ozone and/or sulfur dioxide treatments did not consistently reduce yield, however, they did cause changes in foliar chlorophyll and sulfur concentrations. The 1980 unfiltered ambient air containing high concentrations of ozone caused a yield reduction of approximately four percent compared to soybeans grown in chambers with filtered air.

Pratt, G.C.

1982-01-01

358

Reduction in soybean seed yields by ozone air pollution  

Energy Technology Data Exchange (ETDEWEB)

The National Crop Loss Assessment Network (NCLAN) determined that soybeans were more sensitive to ozone than other major agricultural crops, including corn, wheat, and cotton. The estimated production losses for soybeans at ambient levels of ozone ranged from 7.9 to 18.6 percent compared to 0.6 to 3.1 percent for corn. The research on soybeans was conducted in Illinois, North Carolina, Maryland, and New York. The loss estimates were obtained from field experiments using open-top chambers with charcoal-filtered (CF) air, nonfiltered (NF) air, and NF air with the addition of two or more increments of ozone. However, New Jersey scientists in two recent reports question the validity of the NCLAN results since the utilization of a different method to assess the impact of exposure of ambient O/sub 3/ on soybeans failed to show significant yield losses.

Heggestad, H.E.

1988-08-01

359

Ozone chemistry in aqueous solution : ozone decomposition and stabilisation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone is used in many applications in the industry as an oxidising agent for example for bleaching and sterilisation. The decomposition of ozone in aqueous solutions is complex, and is affected by many properties such as, pH, temperature and substances present in the water. Additives can either accelerate the decomposition rate of ozone or have a stabilising effect of the ozone decay. By controlling the decomposition of ozone it is possible to increase the oxidative capacity of ozone. In this...

Eriksson, Margareta

2005-01-01

360

Ozone carcinogenesis in vitro and its co-carcinogenesis with radiation  

International Nuclear Information System (INIS)

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

1988-01-01

 
 
 
 
361

COTTON YIELD RESPONSES TO OZONE AS MEDIATED BY SOIL MOISTURE AND EVAPOTRANSPIRATION  

Science.gov (United States)

Cotton (Gossypium hirsutum L. cv. 'SJ-2'), grown in open-top chambers in the Central Valley of California, was exposed to 6 ozone (O3) treatments ranging from charcoal-filtered (CF) to ambient plus 0.10 ppm O3 (1981) or twice ambient O3 concentrations (1982) for the entire growin...

362

Biological effects of ozone  

Energy Technology Data Exchange (ETDEWEB)

Tropospheric ozone, a classic anthropogenic air pollutant, is going to remain a troublesome byproduct of contemporary civilization for many decades. We have known for some time that the hydrocarbons and nitrogen oxides from motor vehicles, together with actinic radiation, account for local and regional photochemistry leading to prolonged afternoon ozone peaks. We also now know that agricultural burning and intensive animal husbandry elevate regional and mesoscale concentrations of ozone and its precursors, and that remote background levels of ozone have been rising steadily throughout this century. The changes we will have to make in emission controls to appreciably reduce current tropospheric ozone levels will have profound effects on our transportation systems, consumer products, and lifestyles. As a society, we will have to make difficult choices about the levels of ozone-associated health, welfare, and natural system damage we will tolerate, or conversely, how much we are willing to pay for controls which can minimize the damage.

Lippmann, M. (New York Univ. Medical Center, Tuxedo, NY (USA))

1989-09-01

363

Ozone therapy in periodontics.  

Science.gov (United States)

Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics. PMID:22574088

Gupta, G; Mansi, B

2012-02-22

364

Effects of exercise on mice exposed to ozone.  

Science.gov (United States)

The effects of exercise on response to ambient levels of ozone exposure were studied by using a sensitive indicator of the pulmonary effect of ozone, viz., the elevation of reduced glutathione levels in the lungs. Mice were exposed to 0.2, 0.5, or 1.0 ppm ozone for 3 hr daily for 4 days. For exercise study, animals were placed in a rotating cage in which they were alternately exercised and rested every 15 min during exposure periods. The susceptibility of mice to the pulmonary effects of ozone was found to be approximately tripled by concurrent exercise. The results indicate the importance of exercise in the evaluation of health hazards from photochemical smog. PMID:686847

Fukase, O; Watanabe, H; Isomura, K

1978-01-01

365

Ozone generating technology. Ozone hassei gijutsu  

Energy Technology Data Exchange (ETDEWEB)

This paper summarizes an ozone generating technology using silent discharge. The ozone generating device comprises a power supply, a generation container, a material gas feeding device, and a cooling device. A silent discharge with the higher the frequency can use lower discharge voltage to derive the required discharge power. In order to derive voltage and current wave forms suitable for ozone generation, a calculation was performed on ratios of discharge duration to non-discharge duration with respect to three kinds of application wave forms, using one cycle of the applied wave form as one. As a result, it was found that a current-type inverter is a suitable power supply for ozone generation. The material feeding device feeds dry air very low in dew point and suitable for ozone generation, by passing the compressed air generated by a compressor through a freezing dryer and a heatless dryer. The cooling water uses pure water to prevent contamination of the generation container, and circulates by means of a cooling water circulating device. Tests on a prototype 100 g/h-O3 generator verified generation of ozone with satisfactory concentration and efficiency. 4 figs., 1 tab.

Nakano, Y.; Toda, M.; Suwahara, H. (Meidensha Corp., Tokyo (Japan))

1993-07-01

366

Airborne measurements of ozone levels over central Israel  

Energy Technology Data Exchange (ETDEWEB)

Elevated ozone levels have until recently been regarded as mainly an urban pollution problem, first identified with the so-called `Los-Angeles photochemical smog`. However, it is now becoming evident that even higher ozone mixing ratios may be found at rural areas tens of kilometres downwind of urban pollution sources. Recent studies at rural sites both in Israel and in the US. have reported ozone levels exceeding national ambient air quality standards (120 ppbv). Measurements performed (1988-1991) at a rural site in central Israel, some 50 kilometres west of the highly urbanized coastal region, have shown that during the afternoon hours the area was often under the influence of ozone levels that occasionally exceeded 150 ppbv. Analysis of the air mass back trajectories arriving at the rural site showed that only those air parcels originating over the Tel-Aviv metropolitan area (with a population of around 2.5 million) caused elevated ozone mixing ratios at the rural site. The above hypothesis was further supported by the fact that parallel to the increase of ozone at the rural site, elevated carbon monoxide (1 ppmv), isobutane (50 pptv), benzene (50 pptv) and tetrachloroethane (100 pptv) levels were also observed. The study showed a significant correlation (R{sup 2} > 0.8) between the ozone mixing ratio and the NO{sub y} ( sum of all nitrogen oxide compounds excluding N{sub 2}O) concentrations and that between 8 to 12 ozone molecules were present for each NO{sub y} molecule. It appears that significant amounts of precursors emitted in the Tel-Aviv metropolitan area are carried inland under the westerly wind flows and have the potential of producing high ozone concentrations. This article presents the results of an attempt to better quantize the ozone levels over central inland Israel by performing airborne measurements

Peleg, M.; Luria, M.; Sachi, Y.; Matveev, V. [The Fredy and Nadine Herrmann Graduate School of Applied Sciences, Jerusalem (Israel). Environmental Sciences Division

1995-12-31

367

Desempenho e orientação do crescimento do pepino japonês em ambiente protegido / Performance and growth conduction of Japanese cucumber in protected environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliou-se a produção de pepino japonês Tsuyataro, com diferentes métodos de orientação do crescimento das hastes, a partir do controle de brotações laterais das hastes e do número de hastes por planta, realizados através da poda. O trabalho foi desenvolvido no período de outubro a dezembro de 2010, [...] em ambiente protegido em Tangará da Serra-MT, adotando-se o delineamento em blocos casualizados, distribuídos em esquema fatorial 2x3. O primeiro fator foi constituído de desbrota, ou seja, realização ou não da retirada dos ramos laterais das hastes e o segundo fator foi constituído pelo controle do número de hastes por planta: uma, duas e três hastes/planta, em cinco repetições. Foram avaliadas as características número de frutos total e comercial; taxa de frutos comerciais, comprimento, diâmetro, relação comprimento/diâmetro do fruto, produtividade total e comercial de frutos por planta; e massa média dos frutos do pepino. A condução da haste principal sem a retirada dos ramos laterais foi o tratamento que apresentou superioridade com relação ao número de frutos total e comercial por planta (19,4 e 16,0), e também maior produtividade total e comercial de frutos (4.235,8 e 3.438,3 g/planta). Já a poda das brotações laterais promoveu aumento no comprimento, diâmetro e na massa média dos frutos do pepino de 24,5 para 25,1 cm; 3,4 para 3,5 cm e 212,1 para 228,3 g/fruto, respectivamente. Abstract in english The production of the Japanese cucumber Tsuyataro was evaluated using methods of stems growth conduction, controlling the lateral buds and number of stems per plant, through pruning. The research was carried out from October to December 2010, in a protected environment in Tangará da Serra, Mato Gros [...] so state, Brazil, using a randomized blocks design, with five replications, in a factorial scheme (2x3). The first factor was the pruning, i.e., removal or not of lateral stems and the second factor was constituted of the control of number of stems: one, two and three stems per plant, with five replications. We evaluated the following characteristics: total and marketable number of fruits, commercial fruits rate, fruit length, fruit diameter, fruit length/diameter ratio, total and marketable yield of fruit per plant and fruit average weight. The treatment with conduction of the main stem without removal of lateral buds had better performance on total and marketable number of fruits per plant (19.4 and 16.0) and higher total and marketable yield of fruits (4,235.8 and 3,438.3 g per plant). The pruning of lateral buds provided increase in length, diameter and average mass of cucumber fruits of 24.5 to 25.1 cm; 3.4 to 3.5 cm and 212.1 to 228.3 g per fruit, respectively.

Santi, Adalberto; Scaramuzza, Walcylene LMP; Soares, Danilo MJ; Scaramuzza, José Fernando; Dallacort, Rivanildo; Krause, Willian; Tieppo, Rafael Cesar.

368

Performances of diffusion tubes for the measurement of ozone, nitrogen dioxide and sulfur dioxide in ambient air; Performances des tubes a diffusion pour la mesure de l'ozone, du dioxyde d'azote et du dioxyde de soufre dans l'air ambiant  

Energy Technology Data Exchange (ETDEWEB)

Diffusion tube is a simple device of measurement often used, in particular by networks of air quality monitoring, to analyse the spatial distribution of a pollutant on a city. It constitutes a good complement to the continuous monitoring with monitors. This article presents methods using diffusion tubes for the measurements of O{sub 3}, NO{sub 2} and SO{sub 2} in ambient air. Performances of these tubes: detection limit, accuracy, repeatability, and estimation of the error of measures are evaluated and discussed. With the long sampling times (in our study two weeks for SO{sub 2} and NO{sub 2}, and one week for O{sub 3}), these samplers present sufficiently low detection limits (DL < 5 {mu}g.m{sup -3}) to perform measurements of these three pollutants in ambient air. These methods give good repeatability (RSD{sub mean} {approx_equal} 5 %) for NO{sub 2} and O{sub 3}, and medium for SO{sub 2} (RSD{sub mean} {approx_equal} 12 %). Then diffusion tubes are validated on site by comparing their measures to those of the continuous monitors (techniques of reference). The good linearity has been checked between the tubes responses and the contents measured by monitors, the corresponding correlation coefficients are close to 0.9 for the three pollutants. The analysis of measure differences obtained between these two techniques has allowed to estimate errors of measures of diffusion tubes ({+-} 5 {mu}g.m{sup -3} for NO{sub 2}, {+-} 6 {mu}g/m{sup 3} for SO{sub 2} and {+-} 15 {mu}g.m{sup -3} for O{sub 3}). It seems us important to take into consideration these errors for interpretation of map air pollution levels obtained with diffusion tubes. (authors)

Garcia-Fouque, S.; Plansance, H.; Houdret, J.L.; Mathe, F.; Galloo, J.C.; Guillermo, R. [Ecole des Mines de Douai, 59 (France). Dept. Chimie et Environnement

1999-09-01

369

Quality of measurements of ozone precursors  

Energy Technology Data Exchange (ETDEWEB)

The results of measurements of ozone precursors in ambient air may be used for various purposes: analysis of trends in precursor levels; judging the efficiency of emission reduction strategies; checking consistency of emission inventories; source apportionment and assessment of emission factors; and the study of ozone formation processes. It is evident that only reliable measurement results will lead to reliable conclusions in any of these cases. If it is assumed that measurements performed are representative for one or more of the above measurement purposes by appropriate selection of measurement locations and periods, then the reliability of the measurement result is largely based on the following elements: standardization of measurement procedures, including 'ongoing' quality control, standardization of requirements and tests for method validation; standardization of requirements and methods for instrument testing and approval; establishment and maintenance of traceability of measurement results to (inter)nationally accepted measurement standards; regular proficiency testing / interlaboratory comparisons to ensure comparability of measurement results. In this paper, mechanisms and tools for establishment and maintenance of traceability of measurement results of ozone precursors in ambient air are described.

Hafkenscheid, T. [NMi van Swinden Laboratory, Delft (Netherlands)

2004-07-01

370

The origin of ozone  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Highest ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson Circulation. This is thought to be the main mechanism, how mid- and high latitude ozone is generated. By applying the climate-chemistry model E39/C, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analyz...

Grewe, V.

2005-01-01

371

Stratospheric ozone depletion  

Energy Technology Data Exchange (ETDEWEB)

This bibliography focuses solely on stratospheric ozone depletion. Global climate change, a related issue, is not within its scope. The first section contains an overview of stratospheric ozone issues. The second section, entitled 'science', discusses atmospheric chemistry and dynamics, specifically trace gas emissions and ozone/UVB levels. The third section contains citations relating to risk assessment for humans and other organisms. Section IV includes information on domestic and international public policy. The fifth section outlines research on substitutes and alternatives for ozone-depletion substances. Worldwide participants in the Montreal Protocol are listed in the Appendix.

1989-05-01

372

SMM mesospheric ozone measurements  

Science.gov (United States)

The main objective was to understand the secular and seasonal behavior of ozone in the lower mesosphere, 50 to 70 km. This altitude region is important in understanding the factors which determine ozone behavior. A secondary objective is the study of stratospheric ozone in the polar regions. Use is made of results from the SBUV satellite borne instrument. In the Arctic the interaction between chlorine compounds and low molecular weight hydrocarbons is studied. More than 30,000 profiles were obtained using the UVSP instrument on the SMM spacecraft. Several orbits of ozone data per day were obtained allowing study of the current rise in solar activity from the minimum until the present. Analysis of Nimbus 7 SBUV data in Antarctic spring indicates that ozone is depleted within the polar vortex relative to ozone outside the vortex. This depletion confirms the picture of ozone loss at altitudes where polar stratospheric clouds exist. In addition, there is ozone loss above the cloud level indicating that there is another mechanism in addition to ozone loss initiated by heterogeneous chlorine reactions on cloud particles.

Aikin, A. C.

1990-01-01

373

Understanding ozone plant chemistry  

Energy Technology Data Exchange (ETDEWEB)

Ozone is rarely out of the news these days. Depletion of ozone in the stratosphere and the biological consequences of enhanced fluxes of UV radiation to the Earth's surface have, together with the greenhouse effect, brought global air pollution firmly into the international political arena. At the same time, there is concern about high levels of ozone in the lower atmosphere and its effects on plant productivity and human health. This article examines the biochemical pathways of ozone reactions in plants, with particular emphasis on reactions with unsaturated hydrocarbons. 3 refs.

Hewitt, N.; Terry, G. (Lancaster Univ. (United Kingdom))

1992-10-01

374

Responses of sensitive and tolerant bush beans (Phaseolus vulgaris L.) to ozone in open-top chambers are influenced by phenotypic differences, morphological characteristics, and the chamber environment  

International Nuclear Information System (INIS)

Responses of bush bean (Phaseolus vulgaris L.) lines 'S156' (O3-sensitive) and 'R123' (O3-tolerant), and cultivars 'BBL 290' (O3-sensitive) and 'BBL 274' (O3-tolerant) to ambient ozone (O3) were investigated during the 2001 and 2002 growing seasons. Seedlings were grown in pots inside open-top chambers (OTCs), with charcoal filtered (CF) and non-filtered (NF) ambient air, and in non-chambered ambient air (AA) plots. Growth parameters from individual plants were evaluated after harvests at the end of vegetative (V4) and reproductive (R10) growth phases. Results at V4 indicated that CF did not provide additional benefits over NF in 'S156' in 2001 and 2002. In contrast, exposure to CF significantly impaired the growth of 'R123'. At the end of R10, 'S156' produced more pods, most of which remained immature, and contained fewer seeds or were more frequently aborted, whereas pods produced in 'R123' reached pod maturation and senescence more consistently. Despite increased seed weights inside the OTCs, as observed in 'S156', differences between the two lines were insignificant when grown outside OTCs. Results from the 'BBL 290'/'BBL 274' pair, especially at V4 phase, remained inconclusive. Plant morphological characteristics, variabilities in environmental conditions, and 'chamber effects' inside OTCs were influential in determining plant response to ambient O3. - Phenotypic differences, morphological characteristics, and 'chamber effects' inside OTCs are equally influential in determining the responses of beans to O3

2005-08-01

375

Ozonation of sediments from an urban lake: an exploratory investigation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

F. A, Lage Filho; L. R. F, Carvalho; M. L. A, Lopes.

376

Influence of urban ozone in the measurements of the total ozone column in Mexico City  

Energy Technology Data Exchange (ETDEWEB)

In this paper we examine measurements of the thickness of the total ozone column between 1986 and 1989 in Mexico City. We consider the contribution of the surface ozone in measurement of the total ozone column made with the Dobson Spectrophotometer located at the Solar Radiation Laboratory (National University), in the southwest of Mexico City. We consider different depths of the mixing layer depending on the season and we compare our results with those reported for Mauna Loa in Hawaii and Poona in India, at the same latitude as Mexico City. In conclusion we confirm that in highly polluted areas the surface ozone has an important effect on measurements of the total ozone column. [Spanish] En este trabajo se examinan las mediciones del grosor de la columna total de ozono entre 1986 y 1989 en la Ciudad de Mexico. En esta revision se considera la contribucion del ozono superficial a las mediciones efectuadas con el Espectrofotometro Dobson instalado en el Laboratorio de Radiacion Solar de la UNAM al suroeste de la Ciudad de Mexico. Consideramos diferentes capas de mezcla para el ozono dependiendo del periodo estacional y comparamos los resultados obtenidos con los valores de las mediciones reportadas para Mauna Loa en Hawai y Poona en la India, ambos a latitudes similares a la de la Ciudad de Mexico. Nuestra conclusion es que en regiones urbanas con alta contaminacion ambiental, el ozono superficial afecta apreciablemente las mediciones del grosor de la columna total de ozono.

Juarez, A.; Gay, C. [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico); Bravo, J. L. [Instituto de Geofisica, UNAM, Mexico, D.F. (Mexico)

1995-01-01

377

Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere  

International Nuclear Information System (INIS)

A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O3: non-filtered (NF) ambient air or NF+ 40 ppb O3 (NF+). During O3 exposure, soil sampling was performed at two dates according to different plant growth stages. O3 exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O3 concentrations may influence the dynamic of decomposition processes and the turnover of nutrients. - Ozone reduced the individual densities of enchytraeids, collembolans and soil mites in the rhizosphere of winter wheat indirectly via the plant-soil-system.

2009-12-01

378

Spontaneous Growth of ZnCO3 Nanowires on ZnO Nanostructures in Normal Ambient Environment: Unstable ZnO Nanostructures  

Energy Technology Data Exchange (ETDEWEB)

ZnO nanowires, one of the most investigated nanostructures that promise numerous applications in nanophotonics, opto-electronics, and energy, are generally thought to be highly stable under ambient conditions because of their oxide nature. Here, we report that ZnO nanowires are actually extremely unstable even in normal ambient environment (70% RH, and {approx}350 ppm CO{sub 2}) because of atmospheric corrosion. When placed on an oxide substrate (e.g., glass slide) and exposed in air, ZnO nanowires tend to react with airborne moisture and CO{sub 2} to form amorphous ZnCO{sub 3} thin films and nanowires. The factors that specially affect the corrosion of ZnO nanowires in a laboratory environment include CO{sub 2}, humidity, and substrates. Our results suggest that a CO{sub 2}{sup -} and/or moisture-free environment are required in order for optimal applications of ZnO nanowires.

Pan, Z.; Tao, J.; Zhu, Y.; Huang, J.-F.; Paranthaman, M.P.

2009-12-09

379

Factors Affecting the Association between Ambient Concentrations and Personal Exposures to Particles and Gases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Results from air pollution exposure assessment studies suggest that ambient fine particles [particulate matter with aerodynamic diameter ? 2.5 ?g (PM2.5)], but not ambient gases, are strong proxies of corresponding personal exposures. For particles, the strength of the personal–ambient association can differ by particle component and level of home ventilation. For gases, however, such as ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), the impact of home ventilation on perso...

Sarnat, Stefanie Ebelt; Coull, Brent Andrew; Schwartz, Joel David; Gold, Diane R.; Suh Macintosh, Helen H.

2005-01-01

380

Factors Affecting the Association between Ambient Concentrations and Personal Exposures to Particles and Gases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Results from air pollution exposure assessment studies suggest that ambient fine particles [particulate matter with aerodynamic diameter ? 2.5 ?g (PM2.5)], but not ambient gases, are strong proxies of corresponding personal exposures. For particles, the strength of the personal–ambient association can differ by particle component and level of home ventilation. For gases, however, such as ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), the impact of home ventilation on perso...

Sarnat, Stefanie Ebelt; Coull, Brent A.; Schwartz, Joel; Gold, Diane R.; Suh, Helen H.

2006-01-01

 
 
 
 
381

Assessment of ambient air quality in Eski?ehir, Turkey.  

Science.gov (United States)

This paper presents an assessment of air quality of the city Eski?ehir, located 230 km southwest to the capital of Turkey. Only five of the major air pollutants, most studied worldwide and available for the region, were considered for the assessment. Available sulphur dioxide (SO(2)), particulate matter (PM), nitrogen dioxide (NO(2)), ozone (O(3)), and non-methane volatile organic carbons (NMVOCs) data from local emission inventory studies provided relative source contributions of the selected pollutants to the region. The contributions of these typical pollution parameters, selected for characterizing such an urban atmosphere, were compared with the data established for other cities in the nation and world countries. Additionally, regional ambient SO(2) and PM concentrations, determined by semi-automatic monitoring at two sites, were gathered from the National Ambient Air Monitoring Network (NAAMN). Regional data for ambient NO(2) (as a precursor of ozone as VOCs) and ozone concentrations, through the application of the passive sampling method, were provided by the still ongoing local air quality monitoring studies conducted at six different sites, as representatives of either the traffic-dense-, or coal/natural gas burning residential-, or industrial/rural-localities of the city. Passively sampled ozone data at a single rural site were also verified with the data from a continuous automatic ozone monitoring system located at that site. Effects of variations in seasonal-activities, newly established railway system, and switching to natural gas usage on the temporal changes of air quality were all considered for the assessment. Based on the comparisons with the national [AQCR (Air Quality Control Regulation). Ministry of Environment (MOE), Ankara. Official Newspaper 19269; 1986.] and a number of international [WHO (World Health Organization). Guidelines for Air Quality. Geneva; 2000. Downloaded in January 2006, website: http://www.who.int/peh/; EU (European Union). Council Directive 1999/30/EC relating to limit values for sulfur dioxide, nitrogen dioxide and lead in ambient air. Of J Eur Communities L 163: 14-30; 29.6.1999; EU (European Union). Council Directive 2002/3/EC relating to ozone in ambient air. Of J Eur Communities. L 67: 14-30; 9.3.2002.; USEPA (U.S. Environmental Protection Agency). National Ambient Air Quality Standards (NAAQS). Downloaded in January 2006, website: http://www.epa.gov/ttn/naaqs/] ambient air standards, among all the pollutants studied, only the annual average SO(2) concentration was found to exceed one specific limit value (EU limit for protection of the ecosystem). A part of the data (VOC/NO(x) ratio), for determining the effects of photochemical interactions, indicated that VOC-limited regime was prevailing throughout the city. PMID:18291527

Ozden, O; Dö?ero?lu, T; Kara, S

2008-07-01

382

Ozone-induced signaling in Arabidopsis thaliana  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tropospheric ozone (O3) is one of the most common air pollutants in industrialized countries, and an increasing problem in rapidly industrialising and developing countries in Asia, Africa and South America. Elevated concentrations of tropospheric O3 can lead to decrease in photosynthesis rate and therefore affect the normal metabolism, growth and seed production. Acute and high O3 episodes can lead to extensive damage leading to dead tissue in plants. Thus, O3 derived growth defects can lead ...

Ahlfors, Reetta

2008-01-01

383

Aspects of UV-absorption spectroscopy on ozone in effluents of plasma jets operated in air  

International Nuclear Information System (INIS)

Cold plasmas operating under atmospheric conditions have been in the focus of scientific attention not only due to their use in plasma medicine. Many of these plasma sources most notably produce ozone. This work presents a detailed ozone analysis on an atmospheric-pressure plasma jet operated in ambient air using ultraviolet (UV) absorption spectroscopy. A special focus is placed on the question whether other species are involved, or is the absorption signal due to ozone. For this, the wavelength dependence of the optical depth was measured and compared with the theoretical optical depth including the cross section of ozone. The results show that in the case of a MHz frequency driven atmospheric-pressure argon plasma jet the absorption signal in the UV range is solely due to ozone. Furthermore, this finding is verified by spectroscopic measurements in the IR spectral range. Additional space-resolved ozone density measurements are performed in the effluent of this jet with small oxygen admixtures by means of UV absorption spectroscopy. A funnel-shaped spatial ozone profile is found for all investigated oxygen admixtures. The highest ozone density develops on the effluent axis and in close vicinity to the jet nozzle. The maximal detected value is 1.5 × 1016 cm-3 for an oxygen admixture of 1%. In order to compare the results with non-space-resolved ozone detection methods the ozone net production rate is calculated.

2012-09-26

384

Greenhouse gases and recovery of the Earth's ozone layer  

Science.gov (United States)

A numerical two-dimension zonally average interactive dynamical radiative-photochemical model of the atmosphere is used for investigation the role of the greenhouse gases CO2, CH4, and N2O in the recovery of the Earth's ozone layer after reduction of anthropogenic discharges in the atmosphere of chlorine and bromine compounds. The model allows calculating self-consistently diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of types I and II. The scenarios of future changes of the greenhouse gases and chlorine and bromine species are taken from Climate Change 1995. The calculations show that expected cooling of the stratosphere caused by the increasing of the greenhouse gases, particularly CO2, enhances the ozone concentration in the stratosphere due to a weakness of the efficiencies of all catalytic cycles of the ozone destruction caused by temperature dependencies of photochemical reactions. The result of this effect is a significant acceleration of the ozone layer recovery after reduction of anthropogenic discharges in the atmosphere of chlorine and bromine species. On the other hand, the cooling of the stratosphere intensifies a formation of the polar stratospheric clouds in the lower stratosphere in the Polar Regions. Heterogeneous reactions on the polar stratospheric clouds, which are the key processes in the destruction of the ozone layer at the high latitudes, lead to more intensive ozone depletion here, which causes a delay of the ozone layer recovery. The calculations show that this effect is weaker than the first one so that the global ozone will recover faster under conditions of continuing anthropogenic growth of the greenhouse gases. The model predicts in this case that the annual average global ozone will reach its undisturbed level of 1980 by about 2040. If the growth of the greenhouse gases is stopped, the global ozone will reach this level only in the end of the 21st century.

Dyominov, I. G.; Zadorozhny, A. M.

385

Effect of ambient-level gas-phase peroxides on foliar injury, growth, and net photosynthesis in Japanese radish (Raphanus sativus)  

Energy Technology Data Exchange (ETDEWEB)

To investigate the effects of ambient-level gas-phase peroxides concurrent with O{sub 3} on foliar injury, photosynthesis, and biomass in herbaceous plants, we exposed Japanese radish (Raphanus sativus) to clean air, 50 ppb O{sub 3}, 100 ppb O{sub 3}, and 2-3 ppb peroxides + 50 ppb O{sub 3} in outdoor chambers. Compared with exposure to 100 ppb O{sub 3}, exposure to 2-3 ppb peroxides + 50 ppb O{sub 3} induced greater damage in foliar injury, net photosynthetic rates and biomass; the pattern of foliar injury and the cause of net photosynthetic rate reduction also differed from those occurring with O{sub 3} exposure alone. These results indicate for the first time that sub-ppb peroxides + 50 ppb O{sub 3} can cause more severe damage to plants than 100 ppb O{sub 3}, and that not only O{sub 3}, but also peroxides, could be contributing to the herbaceous plant damage and forest decline observed in Japan's air-polluted urban and remote mountains areas. - Ambient-level gas-phase peroxides coexisted with 50 ppb O{sub 3} may contribute to the herbaceous plants damage and forest decline observed in Japan.

Chen Xuan, E-mail: xuan66chen@yahoo.co.j [Chinese Research Academy of Environmental Science, No.8, Dayangfang, Anwai, Chaoyang District, Beijing 100012 (China); Aoki, Masatoshi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu-shi, Tokyo 183-8509 (Japan); Takami, Akinori [National Institute for Environmental Studies, Onogawa 16-2, Tsukuba-shi, Ibaraki 305-8506 (Japan); Chai Fahe [Chinese Research Academy of Environmental Science, No.8, Dayangfang, Anwai, Chaoyang District, Beijing 100012 (China); Hatakeyama, Shiro [Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu-shi, Tokyo 183-8509 (Japan)

2010-05-15

386

Decrease of ozone above Antarctica  

Energy Technology Data Exchange (ETDEWEB)

Total ozone levels over Antarctica have declined by about 50% over the past decade, principally during spring seasons. This unanticipated change in the total ozone column has initiated a great deal of research into the dynamics and chemistry of the Antarctic atmosphere. Observations of ozone are reviewed. Models to explain the change in ozone abundances are described. The current status of the evidence supporting various theories of the behaviour of ozone in the Antarctic are summarized. 3 figs., 5 refs.

Kelder, H.

1988-11-01

387

A miniaturized kit for ozone biomonitoring  

Energy Technology Data Exchange (ETDEWEB)

A new miniaturized kit based on very young supersensitive tobacco Bel-W3 plantlets, which can be easily used to detect phytotoxic levels of ozone in ambient air in large scale surveys, is described. It has been developed in laboratory as well as field studies. The optimal sampling time is 5-7 d. The advantages of the kit are its user-friendliness, low cost, and reliability. The kit may be integrated by a passive sampling tube set and may be also proposed for educational programs. 6 refs., 2 figs.

Lorenzini, G. [The University, Pisa (Italy)

1994-07-01

388

On the Size of the Antarctic Ozone Hole  

Science.gov (United States)

The Antarctic ozone hole is a region of extremely large ozone depletion that is roughly centered over the South Pole. Since 1979, the area coverage of the ozone hole has grown from near zero size to over 24 Million sq km. In the 8-year period from 1981 to 1989, the area expanded by 18 Million sq km. During the last 5 years, the hole has been observed to exceed 25 Million sq km over brief periods. In the spring of 2002, the size of the ozone hole barely reached 20 Million sq km for only a couple of days. We will review these size observations, the size trends, and the interannual variability of the size. The area is derived from the area enclosed by the 220 DU total ozone contour. We will discuss the rationale for the choice of 220 DU: 1) it is located near the steep gradient between southern mid-latitudes and the polar region, and 2) 220 DU is a value that is lower than the pre-1979 ozone observations over Antarctica during the spring period. The phenomenal growth of the ozone hole was directly caused by the increases of chlorine and bromine compounds in the stratosphere. In this talk, we will show the relationship of the ozone hole's size to the interannual variability of Antarctic spring temperatures. In addition, we will show the relationship of these same temperatures to planetary-scale wave forcings.

Newman, Paul A.; Nash, Eric R.; Kawa, S. Randolph

2002-01-01

389

Dynamical modes associated with the Antarctic ozone hole  

Directory of Open Access Journals (Sweden)

Full Text Available Generalized Maximum Covariance Analysis (GMCA has been developed and applied to diagnosing the dynamical modes associated with variations in the Antarctic spring ozone hole. GMCA is used to identify the most important patterns of co-variability between interannual ozone mixing ratio variations in the Antarctic region and temperature, zonal, meridional and vertical velocities between 100 and 10 hPa in the same region. The most important two pairs of GMCA time coefficients show large year-to-year variations and trends, which are connected with the growth of the Antarctic Ozone Hole and the increase of ozone depleting substances. The associated spatial patterns of ozone variations may be characterized as being quasi-symmetric and asymmetric about the pole. These patterns of ozone variations are associated with comparable patterns of variations of temperature and winds through most of the vertical domain.

The year 2000 is shown to be dominated by the asymmetric mode, whereas the adjacent year 2001 is dominated by the quasi-symmetric mode. A case study, focusing on the asymmetric differences between these two years, shows the magnitude of the ozone mixing ratio, temperature and zonal wind differences to be in the range of 2 e-6, 10°C and 10 m/s, respectively. Budget calculations show that transport processes contribute substantially to the ozone and temperature changes in the middle stratosphere over the Antarctic continent. However, both radiative and chemical processes also play important roles in the changes.

B. C. Weare

2009-02-01

390

Dynamical modes associated with the Antarctic ozone hole  

Directory of Open Access Journals (Sweden)

Full Text Available Generalized Maximum Covariance Analysis (GMCA has been developed and applied to diagnosing the dynamical modes associated with variations in the Antarctic spring ozone hole. GMCA is used to identify the most important patterns of co-variability between interannual ozone mixing ratio variations in the Antarctic region and temperature, zonal, meridional and vertical velocities between 100 and 10 hPa in the same region. The most important two pairs of GMCA time coefficients show large year-to-year variations and trends, which are connected with the growth of the Antarctic Ozone Hole and the increase of ozone depleting substances. The associated spatial patterns of ozone variations may be characterized as being quasi-symmetric and asymmetric about the pole. These patterns of ozone variations are associated with comparable patterns of variations of temperature and winds through most of the vertical domain.

The year 2000 is shown to be dominated by the asymmetric mode, whereas the adjacent year 2001 is dominated by the quasi-symmetric mode. A case study, focusing on the asymmetric differences between these two years, shows the magnitude of the ozone mixing ratio, temperature and zonal wind differences to be in the range of 2 e–6 kg/kg, 10°C and 10 m/s, respectively. Budget calculations show that transport processes contribute substantially to the ozone and temperature changes in the middle stratosphere over the Antarctic continent. However, both radiative and chemical processes also play important roles in the changes.

B. C. Weare

2009-08-01