WorldWideScience
1

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

2

Effects of ambient ozone on first-year growth and physiology of black cherry (Prunus serotina Ehrh. ) seedlings  

Energy Technology Data Exchange (ETDEWEB)

Black cherry seedlings of two open-pollinated families were exposed to ambient ozone in open plots (100%) and plots receiving non-filtered (95%), half-filtered (60%) and full-filtered (40%) concentrations via open-top chambers between early June and late-September 1992 in a replicated field experiment in central Pennsylvania. Seasonal 24-hour ambient ozone concentration averaged 34 ppb with a peak 1-hour concentration of 110 ppb. Foliar symptoms of ozone damage (adaxial stipple) occurred most prominently in open and non-filtered plots and differed between families. Net photosynthetic rate for both families was significantly lower in open and non-filtered plots compared with half- and full-filtered plots on most dates, while ozone concentration had no consistent effect on leaf conductance or dark respiration. Leaf conductance of the ozone sensitive family was significantly greater than the ozone tolerant family on most dates. First-year height and diameter growth were significantly lower in open and non-filtered plots compared with half- and full-filtered plots for both families.

Kolb, T.E.; Skelly, J.M.; Steiner, K.C.; Dunn, K. (Northern Arizona Univ., Flagstaff (United States) Pennsylvania State Univ., University Park (United States))

1993-06-01

3

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

Science.gov (United States)

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(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(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(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. PMID:18378053

Augustaitis, Algirdas; Bytnerowicz, Andrzej

2008-10-01

4

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

International Nuclear Information System (INIS)

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

5

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

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

6

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

7

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...

8

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

9

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  

Energy Technology Data Exchange (ETDEWEB)

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{sub 3} 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 O{sub 3}. - NPK level above recommended alleviates the adverse effects of ambient ozone on a tropical mustard cultivar.

Singh, Poonam [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, Madhoolika [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)], E-mail: madhoo58@yahoo.com; Agrawal, Shashi Bhushan [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)

2009-03-15

10

Impact of ambient and elevated levels of ozone on growth, reproductive development and yield of two cultivars of rice ( Oryza sativa L.)  

Energy Technology Data Exchange (ETDEWEB)

Tow locally grown high yielding varieties of rice (Oryza sativa L. var Malviya dhan 36 and var shivani), were transplanted within the open top chambers (OTCs) at the age of 20 days. five different experimental plots were designed as open plot (OP), non-filtered chamber (NFCs), NFCs with 10 ppb ozone (O{sub 3}), NFCs with 30 ppb O{sub 3} and filtered chamber (FCs) to assess the impact of ambient and elevated levels of O{sub 3} on rice. Twelve hourly monitoring of O{sub 3} and measurements of meteorological variables were done at experimental site during the growth period of rice plants. Morphological, reproductive, physico logical and biochemical parameters were assessed to evaluate the responses of rice cultivars to ambient and elevated levels of O{sub 3}. (Author)

Agrawal, S. B.; Abhijit, S.

2009-07-01

11

Impact of ambient and elevated levels of ozone on growth, reproductive development and yield of two cultivars of rice ( Oryza sativa L.)  

International Nuclear Information System (INIS)

Tow locally grown high yielding varieties of rice (Oryza sativa L. var Malviya dhan 36 and var shivani), were transplanted within the open top chambers (OTCs) at the age of 20 days. five different experimental plots were designed as open plot (OP), non-filtered chamber (NFCs), NFCs with 10 ppb ozone (O3), NFCs with 30 ppb O3 and filtered chamber (FCs) to assess the impact of ambient and elevated levels of O3 on rice. Twelve hourly monitoring of O3 and measurements of meteorological variables were done at experimental site during the growth period of rice plants. Morphological, reproductive, physico logical and biochemical parameters were assessed to evaluate the responses of rice cultivars to ambient and elevated levels of O3. (Author)

12

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

13

Sensitivity of four hardwood species to ambient ozone in north central Pennsylvania  

Energy Technology Data Exchange (ETDEWEB)

Studies were performed to determine the injury growth response of four native species to ambient ozone on three ridgetop sites of the Allegheny Plateau of north central Pennsylvania. Open-top chambers were established at each site and seedlings of black cherry (Prunus serotina Ehrh.), yellow poplar (Liriodendron tulipifera L.), red oak (Quercus rubra L.), and red maple (Acer rubrum L.) were exposed to ambient air or to charcoal filtered air containing approximately 95, 60 or 40% of ambient ozone in randomized, complete blocks in 1988 and 1989. Black cherry seedlings were also exposed in 1990. Ozone was greatest in 1988 at all sites, and total ozone during the 3-year study was greatest at the westernmost sites. Foliar stipple injury of black cherry and yellow poplar were correlated positively with ozone within and among sites throughout the study. Premature leaf abscission of both species was significantly greater with higher ozone levels at one site in 1988 and 1989. Ozone stipple was not observed on red maple and red oak seedlings. Ambient ozone did not significantly decrease height, basal diameter, or leaf surface area of any species. Possible explanations for temporal and spatial ozone variation and subsequent plant response are discussed. 36 refs., 5 figs., 7 tabs.

Simini, M.; Skelly, J.M.; Davis, D.D.; Savage, J.E.; Comrie, A.C. (Pennsylvania State Univ., Pennsylvania Park, PA (United States))

1992-01-01

14

Long-term exposure to twice-ambient ozone (O3) affects carbon sink strength, allocation and stem growth in adult central European forest trees  

Science.gov (United States)

Amongst air pollutants, ground-level ozone (O3) is potentially the most detrimental to vegetation. Spreading globally, enhanced O3 levels are predicted to increase, in particular, in rapidly developing countries and, thus, O3 must now be considered in climate change scenarios and post-Kyoto policies. Here, we present an appraisal of a unique 8-year free-air O3 fumigation experiment on adult European beech (Fagus sylvatica) and Noway spruce (Picea abies), ecologically and economically important, late-succession tree species in Central Europe. For the first time, whole-plant canopies of naturally grown, 60 to 70 years old forest trees were exposed to twice-ambient O3 levels for a total of eight years. Throughout the study period, enhanced O3 uptake in the elevated O3 treatment affected net C fixation and distinctly weakened the whole-stem growth in beech. In contrast, adult spruce at the same site did not display decline in stem biomass development. Those findings corroborate species-specific sensitivities to O3 reported from previous chamber studies on juvenile beech and spruce trees. Carbon allocation of adult trees, as a mechanistical basis of growth processes, was investigated through stable isotope tracer experiments using 13C depleted CO2 at the canopy level. To this end, a novel free-air CO2 exposure system, named tubeFACE, was developed, which employed micro-porous PVC tubes hanging through the canopy of adult trees. In a 19-day 13CO2/12CO2 labeling experiment, CO2 with a ?13C of -46.9 ‰ was continuously released into the canopy to increase [CO2] by 100 µmol mol-1, resulting in a reduction in ?13C of about 8 ‰. Subsequently, C allocation to respiratory pools of various tree organs was studied. Similar to the reduced stem growth in beech, elevated O3 significantly reduced allocation of labeled C to stem respiration, whereas in spruce such a reduction was not found. Hence, our study underlines the need to understand O3 risks by species, so that modeling approaches merely based on tree performance in general do not appear to be satisfactory in prognosticating consequences of climate change. The empirical assessment proved enhanced ground-level O3 regimes as constituents of climate change with relevance for carbon-budgeting and, hence, the Kyoto process.

Grams, T. E.; Matyssek, R.

2009-12-01

15

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

International Nuclear Information System (INIS)

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

16

Bioindicator plants for ambient ozone in Central and Eastern Europe  

Energy Technology Data Exchange (ETDEWEB)

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.

Manning, W.J.; Godzik, B

2004-07-01

17

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

18

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

Science.gov (United States)

...the Review of the Ozone National Ambient Air Quality Standards...the Review of the Ozone National Ambient Air Quality Standards...commercial forests and urban trees, additional...the Review of the Ozone National Ambient Air Quality...

2012-08-27

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

20

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

Science.gov (United States)

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. PMID:23807179

Hoshika, Yasutomo; Pecori, Francesco; Conese, Ilaria; Bardelli, Tommaso; Marchi, Enrico; Manning, William J; Badea, Ovidiu; Paoletti, Elena

2013-09-01

21

Association between ambient ozone and health outcomes in Prague.  

Czech Academy of Sciences Publication Activity Database

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

H?nová, I.; Malý, Marek; ?ezá?ová, J.; Braniš, M.

2013-01-01

22

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

International Nuclear Information System (INIS)

A meta-analysis was conducted to quantitatively assess the effects of ethylenediurea (EDU) on ozone (O3) injury, growth, physiology and productivity of plants grown in ambient air conditions. Results indicated that EDU significantly reduced O3-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 [O3] on vegetation. - EDU effectively protect plants against ambient ozone.

23

Bioindicator plants for ambient ozone in Central and Eastern Europe.  

Science.gov (United States)

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. PMID:15046838

Manning, W J; Godzik, B

2004-07-01

24

Foliar ozone injury and radial growth of ponderosa pine  

Energy Technology Data Exchange (ETDEWEB)

Foliar injury symptoms and stem diameter growth were measured on well-watered and drought-stressed ponderosa pine seedlings at the end of each of three years of exposure to three levels of ozone: charcoal-filtered air, nonfiltered air, and nonfiltered air plus 1.5 times ambient ozone. Ozone injury indices were constructed by adding percent chlorotic mottle and percent necrosis for each needle age class. Seedlings grown in nonfiltered air plus 1.5 times ambient ozone developed severe foliar injury after two years of exposure and were the only seedlings with significant reductions in radial growth after three seasons of exposure to a mean seasonal ozone concentration of 88 ppB. Foliage that had developed over 30% chlorotic mottle by September of the second year had abscised by September of the following year. Reduction in radial growth was significantly correlated with the amount of foliar injury in well-watered trees, and the best-fit regression equation occurred when percent necrosis was weighted by a factor of four. Regressions between foliar injury indices and radial growth in drought-stressed trees were not significant, nor were regressions between radial growth and foliar injury among well-watered trees with only one year of premature needle abscission. The low correlation between foliar injury and radial growth in well-watered trees and the lack of a significant regression in drought-stressed trees suggest that detection of reductions in stem diameter growth of ponderosa pine in the field in response to ozone injury could be difficult, except for severely injured trees with fewer than two years of foliar retention. 28 refs., 2 figs., 2 tabs.

Temple, P.J. (California Univ., Riverside, CA (United States)); Miller, P.R. (U.S. Forest Service, Riverside, CA (United States))

1994-01-01

25

Ambient Ozone and Emergency Department Visits for Cellulitis  

Directory of Open Access Journals (Sweden)

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

Mieczys?aw Szyszkowicz

2010-11-01

26

Ambient ozone concentration and emergency department visits for panic attacks.  

Science.gov (United States)

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

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

2015-03-01

27

A re-examination of ambient air ozone monitor interferences.  

Science.gov (United States)

Attaining the National Ambient Air Quality Standard (NAAQS) for ozone (O3) could cost billions of dollars nationwide. Attainment of the NAAQS is judged on O3 measurements made by the Federal Reference Method (FRM), ethylene chemiluminescence, or a Federal Equivalent Method (FEM), predominantly ultraviolet (UV) absorption. Starting in the 1980s, FRM monitors were replaced by FEMs so that today virtually all monitoring in the United States uses the UV methodology. This report summarizes a laboratory and collocated ambient air monitoring study of interferences in O3 monitors. Potential interferences examined in the laboratory included water vapor, mercury, o-nitrophenol, naphthalene, p-tolualdehyde, and mixed reaction products from smog chamber simulations of urban atmospheric photochemistry. UV absorption O3 monitors modified for humidity equilibration were also collocated with UV FEM O3 monitors at six sites in Houston, TX, during the 2007 summer O3 season. The results suggest that humidity and interfering species can positively bias (overestimate) O3 measured by FEM monitors used to determine compliance with the O3 standards. The results also suggest that humidity equilibration can mitigate this bias. PMID:21141429

Spicer, Chester W; Joseph, Darrell W; Ollison, Will M

2010-11-01

28

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

Science.gov (United States)

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

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

2012-12-01

29

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

30

A preliminary study on the effects of ozone exposure on growth of the tomato seedlings  

OpenAIRE

A study was conducted to evaluate the consequence of application of ozone for a diminutive period repeatedly on tomato seedlings to enhance their biomass. To study the kinetics of these stress-induced growths in more detail we used short pulses (2 min) of ozone (O3) exposure at high concentrations as elicitor. The seedlings treated with different concentration of ozone (0.1, 0.2, 0.3, 0.4 ppm) are referred to as T1, T2, T3 and T4 seedlings respectively. The seedlings treated with ambient air...

Sudhakar, N.; Nagendra-prasad, D.; Mohan, N.; Murugesan, K.

2008-01-01

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

Silver birch and climate change: variable growth and carbon allocation responses to elevated concentrations of carbon dioxide and ozone  

International Nuclear Information System (INIS)

The effects of elevated concentrations of carbon dioxide and ozone were studied on growth, biomass allocation and leaf area of field-grown ozone-tolerant (Clone 4) and ozone-sensitive (Clone 80) European silver birch trees. Seven-year old trees of both types were exposed for three years to outside and chamber control, (1) twice ambient ozone, (2) twice ambient carbon dioxide, and (3) twice ambient carbon dioxide and twice ambient ozone. No effect on biomass allocation was observed when results of the two clones were analyzed together. Total leaf area showed an increase, and leaf abscission appeared delayed in response to elevated carbon dioxide. Elevated ozone caused the dry mass of roots, branches and mean leaf size to decrease, and autumnal leaf abscission occurred earlier than usual in both clones. In general. the effects of elevated ozone were small, however, the interaction between elevated carbon dioxide and elevated oxygen were significant. When results from the two clones were analyzed separately, stem diameter, volume growth and total biomass of Clone 80 increased when exposed to elevated concentrations of carbon dioxide; elevated concentrations of ozone appeared to have no effect. In Clone 4 elevated ozone caused significant decrease in root and branch biomass, but the effects of elevated carbon dioxide were minimal. Responses to elevated ozone exposure were observed only under ambient carbon dioxide conditions. This response is believed to reflect the great response is believed to reflect the greater quantity of carbohydrates available for detoxification and repair under elevated carbon dioxide conditions. Alternatively, the response may be due to decreased stomatal conductance, thus decreased ozone uptake under elevated carbon dioxide conditions. 45 refs., 6 tabs., 4 figs

33

Silver birch and climate change: variable growth and carbon allocation responses to elevated concentrations of carbon dioxide and ozone  

Energy Technology Data Exchange (ETDEWEB)

The effects of elevated concentrations of carbon dioxide and ozone were studied on growth, biomass allocation and leaf area of field-grown ozone-tolerant (Clone 4) and ozone-sensitive (Clone 80) European silver birch trees. Seven-year old trees of both types were exposed for three years to outside and chamber control, (1) twice ambient ozone, (2) twice ambient carbon dioxide, and (3) twice ambient carbon dioxide and twice ambient ozone. No effect on biomass allocation was observed when results of the two clones were analyzed together. Total leaf area showed an increase, and leaf abscission appeared delayed in response to elevated carbon dioxide. Elevated ozone caused the dry mass of roots, branches and mean leaf size to decrease, and autumnal leaf abscission occurred earlier than usual in both clones. In general. the effects of elevated ozone were small, however, the interaction between elevated carbon dioxide and elevated oxygen were significant. When results from the two clones were analyzed separately, stem diameter, volume growth and total biomass of Clone 80 increased when exposed to elevated concentrations of carbon dioxide; elevated concentrations of ozone appeared to have no effect. In Clone 4 elevated ozone caused significant decrease in root and branch biomass, but the effects of elevated carbon dioxide were minimal. Responses to elevated ozone exposure were observed only under ambient carbon dioxide conditions. This response is believed to reflect the greater quantity of carbohydrates available for detoxification and repair under elevated carbon dioxide conditions. Alternatively, the response may be due to decreased stomatal conductance, thus decreased ozone uptake under elevated carbon dioxide conditions. 45 refs., 6 tabs., 4 figs.

Riikonen, J.; Holopainen, T.; Oksanen, E. [University of Kuopio (Finland); Lindsberg, M-M.; Lappi, J.; Peltonen, P.; Vapaavuori, E. [Finnish Forest Research Institute, Suonenjoki Research Station (Finland)

2004-11-01

34

U.S. EPA'S OZONE EPIDEMIOLOGY RESEARCH PROGRAM: A STRATEGY FOR ASSESSING THE EFFECTS OF AMBIENT OZONE EXPOSURE UPON MORBIDITY IN EXPOSED POPULATIONS  

Science.gov (United States)

The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. n order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potenti...

35

Coupled model identifies effect of ozone stress on vegetative growth  

Science.gov (United States)

An intricate feedback system ties together the activity of vegetation and tropospheric ozone. Ground level ozone, drawn from the atmosphere through dry deposition, stresses plants, inhibiting their growth. Plants, in turn, release biogenic volatile organic compounds (VOCs), chemicals that can either enhance or inhibit the deposition of ozone depending on the availability of another class of chemicals, nitrous oxides. Adding to important vegetative processes such as photosynthesis or evapotranspiration, biogenic aerosols can also increase or decrease ozone formation by modulating heat waves. Therefore, understanding the bidirectional interaction between ozone and vegetative growth is important for accurately representing the climate.

Schultz, Colin

2012-10-01

36

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 ozonesure assessments of ozone

37

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

Science.gov (United States)

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 degrees 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) cm(3) s(-1) with detection limit of 58.8 microg 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. PMID:18291125

Lee, I-Su; Tsai, Shih-Wei

2008-03-10

38

Ambient Trend Analysis of Ozone and Particulate Matter in Central California  

Science.gov (United States)

Ambient trends of ozone and PM2.5 were analyzed for recent decades in three major air basins of central California: San Francisco Bay Area (SFBA), Sacramento area, and the San Joaquin Valley (SJV). All three air basins have been designated as in nonattainment of the federal 8-hour ozone and 24-hour PM2.5 standards. All three regions have rigorous, but similar emission reduction programs that have reduced anthropogenic emissions 40 to 50 percent from 1990 to 2010. We have looked at ambient trends of various ozone and PM2.5 metrics including the mean, the maximum, selected percentiles, the number of exceedances of standards, and the number of exceedances of some selected thresholds. In order to assess the true impacts of the region's emission controls on ambient pollutant levels, the trends were adjusted based on meteorological conditions. We compared the cumulative distributions of pollutant concentrations in different decades using percentile-percentile (p-p) plots. The p-p plots showed that for both ozone and PM2.5, the highest percentiles of pollutant levels were reduced by the greatest proportions for all three regions. The selected lowest percentiles for PM remained relatively unchanged, whereas the selected lowest percentiles for ozone increased. Plotting the tails of the cumulative distributions showed how small reductions in peak concentrations can lead to large reductions in exceedances and instances of exposure. These results suggest that, in general, peak ozone exposure has decreased in all three regions, but exposure to moderate ozone concentrations has increased, at least in some areas of the regions. PM exposure has been reduced for all locations, with exposure to the highest concentrations dropping considerably. The health effects of the PM trends show benefits for all areas of the regions. The health effects of the ozone trends depend on the relative health impact from different parts of the ozone distribution.

Fairley, D.; Beaver, S.; Tanrikulu, S.

2011-12-01

39

Heated stainless steel tube for ozone removal in the ambient air measurements of mono- and sesquiterpenes  

Science.gov (United States)

Heated stainless steel inlets were optimized for the ozone removal and for the measurements of mono- and sesquiterpenes in ambient air. Five different inlets were used with different flows, temperatures and ozone and biogenic volatile organic compound (BVOC) concentrations. Both ozone removal capacities and recoveries of BVOCs were determined. Ozone and BVOCs were flushed through the inlet and recoveries were measured by an ozone monitor and adsorbent tube sampling of BVOCs with subsequent analysis with thermal desorption - gas chromatograph (GC) - mass spectrometer (MS). Recovery tests of BVOCs were conducted both with zero air and with ozone rich air. Inlets were optimized especially for online-GC and adsorbent tube measurements of mono- and sesquiterpenes. The results of this study show that it was possible to remove ozone without removing most VOCs with this set-up. Setting the temperature, stainless steel grade and flow correctly for different inlet lengths was found to have a crucial role. The results show that the ozone removal capacity increases with increasing temperature and inlet length. Stainless steel grade 316 was found to be more efficient than grade 304 with respect to ozone removal. Based only on the ozone removal capacity, the longest possible stainless steel inlet with heating would be the optimum solution. However, the recoveries of studied compounds had to be considered too. Of the tested set-ups, a 3 m inlet (¼ in. grade 304) heated to 120 °C with a flow of 1 or 2 l min-1 was found to give the best results with respect to the ozone removal efficiency and compound recovery. This inlet was removing ozone efficiently for at least 4 months when used for ambient air sampling at a rural forested site with a flow of 1 l min-1 (˜170 m3 of air flushed through the tube). A heated (140 °C) 1 m inlet (¼ in. grade 304 or ? in. grade 316) was able to remove ozone with a constant flow of 0.8-1 l min-1 for about two weeks (˜18 m3 of air) and had acceptable recoveries for all other studied compounds except for linalool. This inlet was found to be suitable also for ozone removal in adsorbent tube sampling when the flow is low (0.1 l min-1).

Hellén, H.; Kuronen, P.; Hakola, H.

2012-09-01

40

Serum clara cell protein: a sensitive biomarker of increased lung epithelium permeability caused by ambient ozone.  

OpenAIRE

Ozone in ambient air may cause various effects on human health, including decreased lung function, asthma exacerbation, and even premature mortality. These effects have been evidenced using various clinical indicators that, although sensitive, do not specifically evaluate the O(3)-increased lung epithelium permeability. In the present study, we assessed the acute effects of ambient O(3) on the pulmonary epithelium by a new approach relying on the assay in serum of the lung-specific Clara cell...

Broeckaert, F.; Arsalane, K.; Hermans, C.; Bergamaschi, E.; Brustolin, A.; Mutti, A.; Bernard, A.

2000-01-01

41

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.

42

Modeling the effects of ozone on soybean growth and yield.  

Science.gov (United States)

A simple mechanistic model was developed based on an existing growth model in order to address the mechanisms of the effects of ozone on growth and yield of soybean [Glycine max. (L.) Merr. 'Davis'] and interacting effects of other environmental stresses. The model simulates daily growth of soybean plants using environmental data including shortwave radiation, temperature, precipitation, irrigation and ozone concentration. Leaf growth, dry matter accumulation, water budget, nitrogen input and seed growth linked to senescence and abscission of leaves are described in the model. The effects of ozone are modeled as reduced photosynthate production and accelerated senescence. The model was applied to the open-top chamber experiments in which soybean plants were exposed to ozone under two levels of soil moisture regimes. After calibrating the model to the growth data and seed yield, goodness-of-fit of the model was tested. The model fitted well for top dry weight in the vegetative growth phase and also at maturity. The effect of ozone on seen yield was also described satisfactorily by the model. The simulation showed apparent interaction between the effect of ozone and soil moisture stress on the seed yield. The model revealed that further work is needed concerning the effect of ozone on the senescence process and the consequences of alteration of canopy microclimate by the open-top chambers. PMID:15092277

Kobayashi, K; Miller, J E; Flagler, R B; Heck, W W

1990-01-01

43

Response of different-aged black cherry trees to ambient ozone exposure  

Energy Technology Data Exchange (ETDEWEB)

Black cherry (Prunus serotina Ehrh.) is a valuable commercial timber species which is also highly sensitive to ozone relative to other eastern deciduous tree species. Studies of ozone effects on forest trees have been restricted mostly to experiments using small seedlings under controlled conditions. Yet, mature trees may differ from seedlings in physiology, morphology, and exposure to air pollutants. An experiment was conducted in 1993 to determine differences in ozone uptake and foliar injury symptoms between open-ground seedlings, forest saplings, and mature forest trees of black cherry in northcentral Pennsylvania. Seedlings grew under the highest ozone concentrations and also had greater seasonal ozone uptake due to higher rates of stomatal conductance. However, because of their indeterminate growth habit, seedlings had lower cumulative ozone uptake per leaf lifespan than saplings or mature trees, both of which had determinate shoot growth. Although greater initially for seedlings, foliar injury was nearly identical between size classes by the end of the growing season. Leaves in the lower crown of larger trees had lower ozone uptake than leaves in the upper crown, but exhibited more foliar injury symptoms. Lower crown leaves received more effective exposure to ozone because of their thinner leaves and had less available photosynthate for repair or replacement of damaged tissue.

Fredericksen, T.S.; Joyce, B.J.; Kouterick, K.B.; Kolb, T.E.; Skelly, J.M.; Steiner, K.C.; Savage, J.E.; Snyder, K.R. (Pennyslvania State Univ., Univ. Park, PA (United States))

1994-06-01

44

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

Energy Technology Data Exchange (ETDEWEB)

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{sup -4} cm{sup 3} s{sup -1} with detection limit of 58.8 {mu}g m{sup -3} h{sup -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.

Lee, I-S. [Institute of Environmental Health, College of Public Health, National Taiwan University, No. 17, Xuzhou Road, Taipei 100, Taiwan (China); Tsai, S.-W. [Institute of Environmental Health, College of Public Health, National Taiwan University, No. 17, Xuzhou Road, Taipei 100, Taiwan (China)], E-mail: shihweitsai@ntu.edu.tw

2008-03-10

45

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

46

Effect of ozone on growth and assimilate partitioning in parsley  

Energy Technology Data Exchange (ETDEWEB)

Parsley (Petroselinum crispum (Mill.) Nym. cv. Banquet) incurred leaf injury, reduced growth, and altered assimilate partitioning after exposures to 20 pphm ozone. Total plant dry weight and root dry weight were decreased 23% and 43% respectively, with little effect on leaves. The relative growth rate of fumigated plants was reduced after the initial ozone exposure but leveled off at a steady state above that of the control plants when plant dry weights reached about 4.5 g. Ozone appeared to have its greatest effect on growth during initial exposures. 15 references, 3 figures, 1 table.

Oshima, R.J.; Bennett, J.P.; Braegelmann, P.K.

1978-05-01

47

Salicylic acid - a potential biomarker of tobacco Bel-W3 cell death developed as a response to ground level ozone under ambient conditions.  

Science.gov (United States)

Salicylic acid content and benzoic acid 2-hydroxylase (BA2H) activity were investigated in tobacco Bel-W3 and Bel-B leaves after exposure to tropospheric ozone in the conditions of ambient air. Plants were exposed in accordance with a standard methodology for ozone biomonitoring, in a three-year experiment. Free salicylic acid (SA), conjugated with glucose (SAG), and as a product of the BA2H activity was quantified with HPLC. In order to evaluate ozone injuries of leaves, an open source image analysis software was employed. Plants exposure to ambient ozone resulted in enhanced BA2H activity and intensified salicylic acid biosynthesis in leaves of Bel-W3 cultivar showing visible ozone injuries. The BA2H activity significantly correlated with SAG for ozone-exposed Bel-W3 plants. Both injuries and salicylic acid biosynthesis rate depended on the growth phase of leaves and nearly linear correlation between SA content and injuries was found for particular leaves of Bel-W3. PMID:22695522

Drzewiecka, Kinga; Borowiak, Klaudia; Bandurska, Hanna; Golinski, P

2012-06-01

48

Modeling the effects of reformulated gasoline usages on ambient concentrations of ozone and five air toxics  

International Nuclear Information System (INIS)

The use of reformulated gasolines to reduce motor-vehicle-related hydrocarbon emissions has been mandated by the 1990 Clean Air Act Amendments for nine severely polluted urban areas. Using a version of the Urban Airshed Model that includes explicit representation of five motor-vehicle-related air toxics, the effects of reformulated gasoline usage on ambient ozone and toxics concentrations were simulated. Simulations were conducted for two urban areas. Baltimore-Washington and Houston, for the year 1995. Additional simulation were conducted for Baltimore-Washington including winter and 1999 scenarios. In the Baltimore-Washington areas, the 1995 Federal reformulated gasoline scenario produce reductions of 1.1 percent in simulated peak ozone and 2.7 percent in the areal extent of simulated ozone exceedances. Simulated ozone reductions were much smaller in Houston. In the reformulated gasoline simulations, secondary formulation of formaldehyde and acetaldehyde was reduced, and decreases in ambient benzene and polycyclic organic matter (POM) concentrations were simulated. Larger reductions in ozone and toxics concentrations were simulated for reformulated gasolines meeting California Phase II standards than for those meeting Federal standards. The effects of reductions in motor-vehicle-related nitrogen oxides (NOx) emissions, alone and in combination with hydrocarbon reductions, were also examined

49

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

50

Relationship between summertime ambient ozone levels and emergency department visits for asthma in central New Jersey  

Energy Technology Data Exchange (ETDEWEB)

The 5-year retrospective study of the association between temperature and emergency department (ED) visits for asthma with mean ambient ozone levels between 10:00 and 15:00 was conducted in central New Jersey during the summer months. An association was identified in each of the years (1986-1990). Between 8 and 34% of the total variance in ED visits for asthma was explained by the two environmental variables in the step-wise multiple regression analysis. ED visits occurred 28% more frequently when the mean ozone levels were >0.06 ppm than when they were < 0.06 ppm. This result was statistically significant in a covariance analysis. An evaluation of the effects of ozone on asthmatics reported in the literature was completed to determine if, as proposed by Bates, the results from different types of studies were coherent among the health metrics. A consistency in the magnitude of reported effects and the time lag between exposure and response for four different health indices (symptom reports, decrements in expiratory flow, ED visits, and hospital admissions) was identified and indicates a coherence between ozone and respiratory response to ozone exposure. This supports a proposition that ozone adversely affects asthmatics at levels below the current U.S. standard. 34 refs., 1 fig., 4 tabs.

Weisel, C.P.; Cody, R.P.; Lioy, P.J. [Rutgers Univ., Piscataway, NJ (United States)

1995-03-01

51

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

52

The effect of different atmospheric ozone partial pressures on photosynthesis and growth of nine fruit and nut tree species.  

Science.gov (United States)

Nursery stock of peach (Prunus persica L. Batsch, cv. O'Henry), nectarine (P. persica L. Batsch, cv. Fantasia), plum (P. salicina Lindel., cv. Casselman), apricot (P. armeniaca L., cv. Tilton), almond (P. dulcis Mill., cv. Nonpareil), prune (P. domestica L., cv. Improved French), cherry (P. avium L., cv. Bing), oriental pear (Pyrus pyrifolia Rehd., cv. 20th Century), and apple (Malus pumula Mill., cv. Granny Smith) were planted in open-top chambers on April 1, 1988 at the University of California's Kearney Agricultural Center located in the San Joaquin Valley (30 degrees 40' N 119 degrees 40' W). Trees were exposed to three atmospheric ozone partial pressures (charcoal-filtered air (C), ambient air (A), or ambient air + ozone (T)) from August 1 to November 17, 1988. The mean 12-h (0800 to 2000 h) ozone partial pressures measured in open-top chambers during the experimental period were 0.030, 0.051, and 0.117 microPa Pa(-1) in the C, A and T treatments, respectively. Leaf net CO(2) assimilation rate decreased linearly with increasing 12-h mean ozone partial pressure for the almond, plum, apricot, prune, pear, and apple cultivars. Stomatal conductances of apricot, apple, almond, and plum decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, and pear decreased linearly with increasing ozone partial pressure. Net CO(2) assimilation rate, stomatal conductance, and trunk growth of cherry, peach and nectarine were unaffected by the ozone treatments. Reduced leaf gas exchange probably contributed to ozone-induced growth reduction of the susceptible species and cultivars. Several of the commercial fruit tree species and cultivars studied were relatively tolerant to the ozone treatments. PMID:14972900

Retzlaff, W A; Williams, L E; DeJong, T M

1991-01-01

53

Long-term ambient ozone concentration and the incidence of asthma in nonsmoking adults: The Ahsmog study  

Energy Technology Data Exchange (ETDEWEB)

The authors conducted a prospective study of a cohort of 3091 nonsmokers, ages 27 to 87 years, to evaluate the association between long-term ambient ozone exposure and development of adult-onset asthma. Over a 15-year period, 3.2% of males and 4.3% of females reported new doctor diagnoses of asthma. For males, they observed a significant relationship between report of doctor diagnosis of asthma and 20-year mean 8-h average ambient ozone concentration. The authors observed no such relationship for females. Other variables significantly related to development of asthma were a history of ever-smoking for males, and for females, number of years worked with a smoker, age, and a history of childhood pneumonia or bronchitis. Addition of other pollutants to the models did not diminish the relationship between ozone and asthma for males. These data suggest that long-term exposure to ambient ozone is associated with development of asthma in adult males.

McDonnell, W.F. [Environmental Protection Agency, Research Triangle Park, NC (United States). National Health and Environmental Effects Research Lab.; Abbey, D.E.; Nishino, N. [Loma Linda Univ., CA (United States). School of Public Health; Lebowitz, M.D. [Univ. of Arizona Coll. of Medicine, Tucson, AZ (United States).

1999-02-01

54

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

55

Did the ambient ozone affect stem increment of Scots Pines (Pinus sylvestris L.) on territories under regional pollution load? Step III of Lithuanian studies.  

Science.gov (United States)

This study aimed to explore if changes in stem increment of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone concentration when the impact of tree dendrometric parameters (age, diameter) and crown defoliation are accounted for. More than 200 dominant and codominant trees from 12 pine stands, for which crown defoliation had been assessed since 1994, were chosen for increment boring and basal area increment computing. Stands are located in Lithuanian national parks, where since 1994-95 Integrated Monitoring Stations have been operating. Findings of the study provide statistical evidence that peak concentrations of ambient ozone (O3) can have a negative impact on pine tree stem growth under field conditions where O3 exposure is below phytotoxic levels. PMID:17450281

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

2007-01-01

56

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

57

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

Energy Technology Data Exchange (ETDEWEB)

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

Preisler, Haiganoush K., E-mail: hpreisler@fs.fed.u [USDA Forest Service, Pacific Southwest Research Station, 800 Buchanan St, Albany, CA 94710 (United States); Zhong Shiyuan, E-mail: zhongs@msu.ed [Department of Geography, Michigan State University, 116 Geography Building, East Lansing, MI 48824-1117 (United States); Esperanza, Annie, E-mail: annie_esperanza@nps.go [Sequoia and Kings Canyon National Parks, 47050 Generals Highway Three Rivers, CA 93271 (United States); Brown, Timothy J., E-mail: tim.brown@dri.ed [Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89521-10095 (United States); Bytnerowicz, Andrzej, E-mail: abytnerowicz@fs.fed.u [USDA Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States); Tarnay, Leland, E-mail: Leland_Tarnay@nps.go [Yosemite National Park, El Portal, CA 95318 (United States)

2010-03-15

58

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

International Nuclear Information System (INIS)

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

59

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

Directory of Open Access Journals (Sweden)

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

S. Deb Roy

2009-07-01

60

CHANGES IN PULMONARY FUNCTION AND AIRWAY REACTIVITY DUE TO PROLONGED EXPOSURE TO TYPICAL AMBIENT OZONE (O3) LEVELS  

Science.gov (United States)

Daily ambient ozone levels between 0.08 and 0.12 ppm for periods exceeding 6 hours often occur in many urban, suburban, and rural areas of the United States and Europe. Substantial decrements in pulmonary functions, moderate to severe respiratory symptoms, and increased airway re...

61

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-07-01

62

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

63

Ambient ozone in forests of the Central and Eastern European mountains  

Energy Technology Data Exchange (ETDEWEB)

Ambient ozone (O{sub 3}) concentrations in the forested areas of the Central and Eastern European (CEE) mountains measured on passive sampler networks and in several locations equipped with active monitors are reviewed. Some areas of the Carpathian Mountains, especially in Romania and parts of Poland, as well as the Sumava and Brdy Mountains in the Czech Republic are characterized by low European background concentrations of the pollutant (summer season means {approx}30 ppb). Other parts of the Carpathians, especially the western part of the range (Slovakia, the Czech Republic and Poland), some of the Eastern (Ukraine) and Southern (Romania) Carpathians and the Jizerske Mountains have high O{sub 3} levels with peak values >100 ppb and seasonal means {approx}50 ppb. Large portions of the CEE mountain forests experience O{sub 3} exposures that are above levels recommended for protection of forest and natural vegetation. Continuation of monitoring efforts with a combination of active monitors and passive samplers is needed for developing risk assessment scenarios for forests and other natural areas of the CEE Region. - Ozone concentrations in Central and Eastern European mountain ranges are elevated and phytotoxic to sensitive vegetation.

Bytnerowicz, A.; Godzik, B.; Grodzinska, K.; Fraczek, W.; Musselman, R.; Manning, W.; Badea, O.; Popescu, F.; Fleischer, P

2004-07-01

64

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

International Nuclear Information System (INIS)

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

65

Growth of northeast arctic cod in relation to ambient temperature  

OpenAIRE

In the present study temperature related changes in horizontal distribution are described and the influence of temperature on the growth of Northeast Arctic cod is interpreted. Data from acoustic-and bottom trawl surveys in the Barents Sea each February 1988-1995 has been used to relate mean length at age to the ambient winter temperature. Mean lengths at age increased with increasing temperature for ages greater than 2 years. Individual mean growth between age 1 and age 4 was significantly h...

Michalsen, Kathrine; Ottersen, Geir; Nakken, Odd

1996-01-01

66

The role of elevated ozone on growth, yield and seed quality amongst six cultivars of mung bean.  

Science.gov (United States)

Tropospheric ozone (O3) can be deleterious to plants by decreasing crop yield and quality. Present study was conducted on six cultivars of mung bean (HUM-1, HUM-2, HUM-6, HUM-23, HUM-24 and HUM-26) grown under ambient O3 (NFC) and elevated O3 levels (ambient+10 ppb; NFC+) in open top chambers (OTCs) for two consecutive years. Ozone monitoring data showed high mean ambient concentration of O3 at the experimental site, which was above the threshold value of 40 ppb. Ozone exposure induced symptoms of foliar injury and also depicted accumulation of reactive oxygen species (ROS) which led to increased membrane damage vis-a-vis solute leakage. Root/shoot allometric coefficient (k), yield and seed quality showed negative response to O3. Differential response of mung bean cultivars against elevated O3 was assessed by comparing the levels of antioxidants, metabolites, growth, total biomass and yield. Cultivar HUM-1 showed maximum sensitivity towards O3 as compared to other cultivars. Findings of present study emphasized the possibility of selection of suitable O3 resistant cultivars for the areas experiencing high concentrations of O3. PMID:25450946

Chaudhary, Nivedita; Agrawal, S B

2015-01-01

67

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

68

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. - Soywhere 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.

69

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)

70

Ozone detection by differential absorption spectroscopy at ambient pressure with a 9.6 µm pulsed quantum-cascade laser  

OpenAIRE

We report direct absorption spectroscopic detection of ozone at ambient pressure with a pulsed, DFB quantum-cascade laser (QCL) tuned within 1044–1050 cm-1 by temperature scanning. Wavelength calibration curves were derived from FTIR and CO2 spectra and interpreted with respect to the heat transfer from the heterostructure to the sink. The laser linewidth (~0.13 cm-1 FWHM) was found to decrease with temperature, probably as a result of operation at constant current. Spurious spectral featur...

Jime?nez, R.; Taslakov, M.; Simeonov, V.; Calpini, B.; Jeanneret, F.; Hofstetter, Daniel; Beck, Mattias; Faist, Je?ro?me; Den Bergh, H.

2008-01-01

71

Estimated Acute Effects of Ambient Ozone and Nitrogen Dioxide on Mortality in the Pearl River Delta of Southern China  

OpenAIRE

Background and objectives: Epidemiologic studies have attributed adverse health effects to air pollution; however, controversy remains regarding the relationship between ambient oxidants [ozone (O3) and nitrogen dioxide (NO2)] and mortality, especially in Asia. We conducted a four-city time-series study to investigate acute effects of O3 and NO2 in the Pearl River Delta (PRD) of southern China, using data from 2006 through 2008.

Tao, Yebin; Huang, Wei; Huang, Xiaoliang; Zhong, Liuju; Lu, Shou-en; Li, Yi; Dai, Lingzhen; Zhang, Yuanhang; Zhu, Tong

2011-01-01

72

Impacts of summer ozone exposure on the growth and overwintering of UK upland vegetation  

Science.gov (United States)

The effects of ozone exposure on species of an upland grassland were assessed. Thirty-three species from Snowdonia, North Wales, UK, were exposed for 10 weeks to a weekly episodic ozone regime in solardomes representing predicted future concentrations. Two solardomes were used as controls, with ozone added to charcoal-filtered air to give a continuous ozone concentration of 30 ppb (O 3(30)). A weekly episodic ozone regime was applied to two other solardomes, with concentrations rising for 8 h per day to 80 ppb on day 1, 100 ppb on days 2 and 3, and 80 ppb on day 4; ozone concentrations remained at 30 ppb at all other times (O 3(30+peaks)). The control and background ozone concentrations of 30 ppb were maintained throughout the night as well as during the daytime. During exposure to the episodic ozone regime, some species were sensitive to ozone and showed ozone-specific leaf injury symptoms (e.g . Carex echinata) and/or premature senescence (e.g. Festuca rubra) and/or changes in above-ground biomass (e.g. Armeria maritima), whereas other species (e.g Holcus lanatus and Carex demissa) showed no effects. Some species, although showing no effects during the 10-week ozone exposure, showed carry-over effects on biomass the following spring, after a winter period of ambient ozone exposure (e.g. Galium saxatile, Nardus stricta and Saxifraga stellaris). The carry-over effects shown in this study indicate the potential ecological impact of ozone on semi-natural vegetation species and indicate the importance of longer-term studies on the effects of ozone on plants.

Hayes, Felicity; Mills, Gina; Williams, Philip; Harmens, Harry; Büker, Patrick

73

Multi-year evaluation of ambient volatile organic compounds: temporal variation, ozone formation, meteorological parameters, and sources.  

Science.gov (United States)

The multi-year characteristics of ambient volatile organic compounds (VOCs) and their source contribution in a selected metropolitan (Seoul) and rural (Seokmolee) areas in Korea were investigated to provide the framework for development and implementation of ambient VOC control strategies. For Seoul, none of the three VOC groups exhibited any significant trend in their ambient concentrations, whereas for Seokmolee, they all showed a generally decreasing trend between 2005 and 2008 and an increasing trend after 2008. Two paraffinic (ethane and propane) and two olefin (ethylene and propylene) hydrocarbons displayed higher concentrations during the cold season than warm season, while the other target VOCs did not exhibit any significant trends. Ethylene and toluene were the first and second largest contributors to ozone formation, respectively, whereas several other VOCs displayed photochemical ozone formation potential values less than 0.01 ppb. For both areas, there was a significant negative correlation between ambient temperature and the selected VOC group concentrations. In contrast, a significant positive correlation was observed between relative humidity and the three VOC group concentrations, while no significant correlation was observed between wind speed and VOC group concentrations. For Seoul, the combination of vehicle exhaust and gasoline/solvent evaporation was the greatest source of VOCs, followed by liquid natural gas (LNG) and liquid petroleum gas (LPG). However, combination of LNG and LPG was the greatest source of VOCs at Seokmolee, followed by the combination of vehicle exhaust and gasoline evaporation, and then biogenic sources. PMID:25632908

Kim, Ku H; Chun, Ho-Hwan; Jo, Wan K

2015-02-01

74

Ozone Pollution  

Medline Plus

Full Text Available ... rising temperatures create conditions favorable to forming ozone. Communities will need more help to reduce ozone pollution ... Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: ...

75

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

OpenAIRE

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 an...

Montserrat Fuentes; Chang, Howard H.; Jingwen Zhou

2010-01-01

76

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  

International Nuclear Information System (INIS)

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.

77

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

International Nuclear Information System (INIS)

Spruce saplings were grown under different nitrogen fertilization regimes in eight chamberless fumigation systems, which were fumigated with either charcoal-filtered (F) or ambient air (O3). After the third growing season trees were harvested for biomass and non-structural carbohydrate analysis. Nitrogen had an overall positive effect on the investigated plant parameters, resulting in increased shoot elongation, biomass production, fine root soluble carbohydrate concentrations, and also slightly increased starch concentrations of stems and roots. Only needle starch concentrations and fine root sugar alcohol concentrations were decreased. Ozone fumigation resulted in needle discolorations and affected most parameters negatively, including decreased shoot elongation and decreased starch concentrations in roots, stems, and needles. In fine roots, however, soluble carbohydrate concentrations remained unaffected or increased by ozone fumigation. The only significant interaction was an antagonistic effect on root starch concentrations, where higher nitrogen levels alleviated the negative impact of ozone. - Simultaneous ozone fumigation and nitrogen fertilization have no synergistic impacts on carbohydrate concentrations, biomass, or growth of Picea abies saplings

78

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-10-15

79

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

80

77 FR 8197 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...  

Science.gov (United States)

...Ozone Design Value Classification Table Translation to 8-Hour Design Values for the...subpart 2 classification table to mean consecutive 365-day periods,\\25\\ and we would...quality during the most recent three full consecutive ozone seasons, and the most...

2012-02-14

81

Responses of Fraxinus excelsior L. seedlings to ambient ozone exposure in urban and mountain areas based on physiological characteristics and antioxidant activity.  

Science.gov (United States)

Effects of ozone on the sensitive tree species Fraxinus excelsior L. exposed to ambient air were investigated. The dynamics of photosynthesis, transpiration, stomatal conductance and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in three-year-old ash seedlings were studied during a four-month period (June-September). Seedlings were exposed to ambient ozone in an urban (the Central City Park of Sofia - Borisova Gradina) and a mountain (Plana Mountain) area in Bulgaria. The sites were located near climate monitoring stations, providing data on ozone concentrations and meteorological parameters. Ozone exposure at the mountain site (AOT40) was more than two times higher compared to the urban site. Significantly higher values of sun radiation, transpiration, stomatal conductance and enzyme activity at the mountain site were also observed. At the urban site higher values of temperature and air humidity were registered. Effects of the measured variables on ash seedlings were complex and interdependent. No direct effect of ozone concentration in ambient air on the leaf physiology and biochemistry could be proved. However, intensified SOD and CAT activity in the presence of elevated ozone suggested antioxidant reaction in response to ozone uptake. PMID:23760537

Parvanova, Petya; Tzvetkova, Nikolina; Bratanova-Doncheva, Svetla; Chipev, Nesho; Fikova, Radka; Donev, Evgeni

2013-07-01

82

Relationship between boundary layer heights and growth rates with ground-level ozone in Houston, Texas  

Science.gov (United States)

Measurements and predictions of ambient ozone (O3), planetary boundary layer (PBL) height, the surface energy budget, wind speed, and other meteorological parameters were made near downtown Houston, Texas, and were used to investigate meteorological controls on elevated levels of ground-level O3. Days during the study period (1 April 2009 to 31 December 2010 for measurements and 15 April 2009 to 17 October 2009 for modeled) were classified into low (LO3) and high ozone (HO3) days. The majority of observed high HO3 days occurred in a postfrontal environment. Observations showed there is not a significant difference in daily maximum PBL heights on HO3 and LO3 days. Modeling results showed large differences between maximum PBL heights on HO3 and LO3 days. Nighttime and early morning observed and modeled PBL heights are consistently lower on HO3 days than on LO3 days. The observed spring LO3 days had the most rapid early morning PBL growth (~350 m h-1) while the fall HO3 group had the slowest (~200 m h-1). The predicted maximum average hourly morning PBL growth rates were greater on HO3 (624 m h-1) days than LO3 days (361 m h-1). Observed turbulent mixing parameters were up to 2-3 times weaker on HO3 days, which indicate large-scale subsidence associated with high-pressure systems (leading to clear skies and weak winds) substantially suppresses mixing. Lower surface layer ventilation coefficients were present in the morning on HO3 days in the spring and fall, which promotes the accumulation of O3 precursors near the surface.

Haman, C. L.; Couzo, E.; Flynn, J. H.; Vizuete, W.; Heffron, B.; Lefer, B. L.

2014-05-01

83

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

Science.gov (United States)

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(3) concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O(3) exposure results in higher MDA contents in P. abies needles under real conditions has not been approved. PMID:20466470

H?nová, Iva; Novotný, Radek; Uhlírová, Hana; Vráblík, Tomás; Horálek, Jan; Lomský, Bohumír; Srámek, Vít

2010-07-01

84

OZONE DECREASES SPRING ROOT GROWTH AND ROOT CARBOHYDRATE CONTENT IN PONDEROSA PINE THE YEAR FOLLOWING EXPOSURE  

Science.gov (United States)

Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. he hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. eedling...

85

77 FR 30160 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...  

Science.gov (United States)

...Ozone Design Value Classification Table Translation to 8-Hour Design Values for the 2008...subpart 2 classification table to mean consecutive 365-day periods,\\15\\ and we would...evaluation of monitoring data from 3 consecutive calendar years running from...

2012-05-21

86

Cultivar specific variations in antioxidative defense system, genome and proteome of two tropical rice cultivars against ambient and elevated ozone.  

Science.gov (United States)

For the past few decades continuous increase in the levels of tropospheric ozone (O3) concentrations is posing to be a threat for agricultural productivity. Two high yielding tropical rice cultivars (Malviya dhan 36 and Shivani) were evaluated against different concentrations of O3 under field conditions. Experimental design included filtered chambers, non-filtered chambers having ambient O3 and 10 and 20ppb elevated O3 above the ambient. Study was conducted to assess differential response if any in induction of antioxidative defense system, genome stability, leaf proteome, yield and quality of the product in both the test cultivars. Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR) were induced under ambient and elevated levels of O3. Native polyacrylamide gel electrophoresis (PAGE) of SOD, CAT and POD also displayed increased enzymatic activity along with associated alterations in specific isoforms. Ascorbic acid, thiols and phenolics were also stimulated at ambient and elevated O3. Structural alterations in DNA of rice plants due to O3 affecting its genome template stability (GTS) was examined using RAPD technique. 2-D PAGE revealed 25 differential spots in Malviya dhan 36 and 36 spots in Shivani after O3 treatment with reductions in RuBisCO subunits. Reductions in yield and change in the quality of grains were also noticed. PMID:25682587

Sarkar, Abhijit; Singh, Aditya Abha; Agrawal, Shashi Bhushan; Ahmad, Altaf; Rai, Shashi Pandey

2015-05-01

87

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

International Nuclear Information System (INIS)

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

88

PILOT STUDY: International Comparison CCQM-P28: Ozone at ambient level  

Science.gov (United States)

We report a pilot study organized within the Consultative Committee for Amount of Substance (CCQM), in which the ozone reference standards of 23 institutes have been compared to one common reference, the BIPM ozone reference standard, in a series of bilateral comparisons carried out between July 2003 and February 2005. The BIPM, which maintains as its reference standard a standard reference photometer (SRP) developed by the National Institute of Standards and Technology (NIST, United States), served as pilot laboratory. A total of 25 instruments were compared to the common reference standard, either directly (16 comparisons) or via a transfer standard (9 comparisons). The comparisons were made over the ozone mole fraction range 0 nmol/mol to 500 nmol/mol. Two reference methods for measuring ozone mole fractions in synthetic air were compared, thanks to the participation of two institutes maintaining a gas-phase titration system with traceability of measurements to primary gas standards of NO and NO2, while the 23 other instruments were based on UV absorption. In the first instance, each comparison was characterized by the two parameters of a linear equation, as well as their related uncertainties, computed with generalized least-squares regression software. Analysis of these results using the Birge ratio indicated an underestimation of the uncertainties associated with the measurement results of some of the ozone standards, particularly the NIST SRPs. As a final result of the pilot study, the difference from the reference value (BIPM-SRP27 measurement result) and its related uncertainty were calculated for each ozone standard at the two nominal ozone mole fractions of 80 nmol/mol and 420 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM.

Viallon, Joële; Moussay, Philippe; Esler, Michael; Wielgosz, Robert; Bremser, Wolfram; Novák, Jirí; Vokoun, Miroslav; Botha, Angelique; Janse Van Rensburg, Mellisa; Zellweger, Christoph; Goldthorp, Sandra; Borowiak, Annette; Lagler, Friedrich; Walden, Jari; Malgeri, Ettore; Sassi, Maria Paola; Morillo Gomez, Pilar; Fernandez Patier, Rosalia; Galan Madruga, David; Woo, Jin-Chun; Doo Kim, Yong; Macé, Tatiana; Sutour, Christophe; Surget, Ana; Niederhauser, Bernhard; Schwaller, Daniel; Frigy, Beata; Györgyné Váraljai, Irén; Hashimoto, Shigeru; Mukai, Hitoshi; Tanimoto, Hiroshi; Ahleson, Hans Peter; Egeløv, Axel; Ladegard, Nils; Marsteen, Leif; Tørnkvist, Kjersti; Guenther, Franklin R.; Norris, James E.; Hafkenscheid, Theo L.; Van Rijn, Martin M.; Quincey, Paul; Sweeney, Bryan; Langer, Sarka; Magnusson, Bertil; Bastian, Juliana; Stummer, Volker; Fröhlich, Marina; Wolf, Andreas; Konopelko, Leonid A.; Kustikov, Yuri A.; Rumyanstev, Dmitry V.

2006-01-01

89

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

International Nuclear Information System (INIS)

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

90

COMBINED OZONE AND ACTIVE OXYGEN TREATMENT OF TOMATOES AND BANANAS DELAYS RIPENING AND REDUCES QUALITY DETERIORATION AND MICROBIAL GROWTH  

Science.gov (United States)

Green bananas and mature tomatoes were subjected to a combination of ozone and active oxygen or ambient air (control) treatment at 10 'C for up to 25 days. Visual observation revealed that bananas stored in the active oxygen and ozone chamber remained greener than those stored in the control chambe...

91

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

Energy Technology Data Exchange (ETDEWEB)

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{sup -2} cumulated ozone uptake, on a projected needle area basis. - Growth reductions by Norway spruce saplings correlate with cumulative needle uptake of ozone.

Karlsson, P.E.; Medin, E.L.; Ottosson, S.; Sellden, G.; Wallin, G.; Pleijel, H.; Skaerby, L

2004-02-01

92

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

93

Effects of ozone on growth, lipid metabolism, and sporulation of fungi. [Colletotrichum lindemuthianum; Alternaria oleraceae  

Energy Technology Data Exchange (ETDEWEB)

Fumigations with ozone at concentrations of 10 pphm or more for 4 hr repeated daily for 4 days suppressed radial growth and spore production of Colletotrichum lindemuthianum, the most sensitive species studied. Neither radial nor mass growth of Alternaria oleraceae, a more tolerant species, was inhibited by 60 pphm ozone, although spore production was significantly accelerated. Since ozone did not affect spore viability, the inoculum potential was greatly enhanced. Histological effects of ozone included loss of pigmentation in C. lindemuthianum and abundant formation of light-refractive globules in the hyphae. Chemical analyses of mycelial mats showed an average 28% decrease in neutral lipid content of ozone-fumigated cultures. No differences were detectable in fatty acid composition of fumigated cultures. While some lipids may have leaked into the substrate, it was suspected that ozone penetrated into vital sites within the cell-oxidizing sulfhydryl groups, thereby suppressing lipid synthesis. The actual degree of suppression in fumigated hyphae may have been greater than indicated, since much of the mycelia analyzed grew within the substrate and was not directly subjected to ozone. 14 references.

Treshow, M.; Harner, F.M.; Price, H.E.; Kormelink, J.R.

1969-09-01

94

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

Science.gov (United States)

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

95

Ozone Dosage Effect on C6 Cell Growth: in Vitro and in Vivo Tests.  

Science.gov (United States)

C6 rat glioma cells are one of the most aggressive carcinogenic tumors, due to high mortality rate in human beings and animals. The current treatment for this illness includes surgery and radio and chemotherapy, showing relapse in patients treat with those therapies. Since the ozone was found an effective bioreactive agent to inhibit growth of several carcinoma cells in vitro and in vivo. In this research, therapeutic peritoneum insufflation of ozone/oxygen dissolved in the physiological solution of NaCl 0.9% was dosage for fifteen days on different groups of female mice with and advanced stage C6 tumor (n=6). The first of them was the control group which had not treatment, the second group was dosage with oxygen every second day, the third group was dosage with ozone every second day, and finally the fourth group was dosage with ozone dissolved every fifth day. The size of the tumor was higher in both groups dosed by ozone; nevertheless tumor activity measured by microPET was 98% less in the fourth group compared with the control group. That proves that the ozone provokes an increase in the tumor volume even though the decrease of the cell activity. Those results were confirmed by hydroperoxides quantification, cholesterol and triglycerides. Double Bond Index (DB-Index), which is a method that determines the quantity of double bonds in an organic sample, to confirm the variation of active sites in the ozone reaction. PMID:25353336

Pérez, Arizbeth; Santos Cuevas, Clara L; Chairez, Isaac; Poznyak, Tatyana; Ordaz-Rosado, David; García-Becerra, Rocío; Romero Piña, Mario E

2014-10-27

96

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

97

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

98

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-09-15

99

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

International Nuclear Information System (INIS)

Beech seedlings were grown under different nitrogen fertilisation regimes (0, 20, 40, and 80 kg N ha-1 yr-1) for three years and were fumigated with either charcoal-filtered (F) or ambient air (O3). Nitrogen fertilisation increased leaf necroses, aphid infestations, and nutrient ratios in the leaves (N:P and N:K), as a result of decreased phosphorus and potassium concentrations. For plant growth, biomass accumulation, and starch concentrations, a positive nitrogen effect was found, but only for fertilisations of up to 40 kg N ha-1 yr-1. The highest nitrogen load, however, reduced leaf area, leaf water content, growth, biomass accumulation, and starch concentrations, whereas soluble carbohydrate concentrations were enhanced. The ozone fumigation resulted in reduced leaf area, leaf water content, shoot growth, root biomass accumulation, and decreased starch, phosphorus, and potassium concentrations, increasing the N:P and N:K ratios. A combined effect of the two pollutants was detected for the leaf area and the shoot elongation, where ozone fumigation amplified the nitrogen effects. - The effects of nitrogen and ozone on growth, carbohydrate concentrations, and nutrients are mainly additive

100

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

International Nuclear Information System (INIS)

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

101

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-05-15

102

Growth response to a changing environment-Impacts of tropospheric ozone dose on photosynthesis of Norway spruce forests in Austria  

Science.gov (United States)

Tropospheric ozone is an important air pollutant, although plants have active defense strategies (e.g. antioxidants), the cumulative ozone dose may lead to chronic damages to plant tissues. Ozone enters into plants through stomata and reacts with other chemicals to create toxic compounds. This affects plant photosynthesis and may reduce CO2 fixation, and consequently growth. Open top cambers (OTC) are usually used to study the effects of elevated ozone levels on photosynthesis; whereas field studies with on site occurring ozone levels are rare. A recent modelling study on Norway spruce stands in Austria exhibited trends in model errors indicating that an increase in ozone dose leads to a reduction in volume increment. This study aims to explore how different ozone doses affect photosynthesis under field conditions and may translate into growth response for 12 stands of Norway spruce, distributed along an ozone concentration gradient across Austria. A LI-6400xt photosynthesis system was utilized to collect physiological parameters including net photosynthesis, stomata conductance, internal CO2 concentration, transpiration, etc. Chlorophyll fluorescence data was collected by using a PEA chlorophyll fluorescence meter, and chlorophyll content was measured. Morphological characteristics and soil samples were also analyzed. Ozone dose to leaf tissue was calculated from external ozone concentration, the conductance of the stomata to ozone, the leaf area index and the time span of the day when ozone uptake takes place. Our results confirm that increasing cumulative ozone dose reduces maximum assimilation rate and carboxylation efficiency under field conditions. Our final goal is to quantify how far this ozone induced reduction in assimilation power ultimately translates into a growth reduction of Norway spruce in Austria.

Liu, Xiaozhen; Pietsch, Stephan; Hasenauer, Hubert

2010-05-01

103

Use of passive ambient ozone (O3) samplers in vegetation effects assessment  

Science.gov (United States)

A stochastistic, Weibull probability model was developed and verified to simulate the underlying frequency distributions of hourly ozone (O3) concentrations (exposure dynamics) using the single, weekly mean values obtained from a passive (sodium nitrite absorbent) sampler. The simulation was based on the data derived from a co-located continuous monitor. Although at the moment the model output may be considered as being specific to the elevation and location of the study site, the results were extremely good. This effort for the approximation of the O3 exposure dynamics can be extended to other sites with similar data sets and in developing a generalized understanding of the stochastic O3 exposure-plant response relationships, conferring measurable benefits to the future use of passive O3 samplers, in the absence of continuous monitoring. Copyright ?? 2000 Elsevier Science Ltd.

Krupa, S.; Nosal, M.; Peterson, D.L.

2001-01-01

104

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...

105

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 unde 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

106

Effect of increased carbon dioxide concentrations on stratospheric ozone  

International Nuclear Information System (INIS)

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

107

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

International Nuclear Information System (INIS)

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

108

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

109

Effects of ambient and acute partial pressures of ozone on leaf net CO sub 2 assimilation of field-grown Vitis vinifera L  

Energy Technology Data Exchange (ETDEWEB)

Mature, field-grown Vitis vinifera L. grapevines grown in open-top chambers were exposed to either charcoal-filtered air or ambient ozone partial pressures throughout the growing season. Individual leaves also were exposed to ozone partial pressures of 0.2, 0.4, or 0.6 micropascals per pascal for 5 hours. No visual ozone damage was found on leaves exposed to any of the treatments. Chronic exposure to ambient O{sub 3} partial pressures reduced net CO{sub 2} assimilation rate (A) between 5 and 13% at various times throughout the season when compared to the filtered treatment. Exposure of leaves to 0.2 micropascals per pascal O{sub 3} for 5 hours had no significant effect on A; however, A was reduced 84% for leaves exposed to 0.6 micropascals per pascal O{sub 3} when compared to the controls after 5 hours. Intercellular CO{sub 2} partial pressure (c{sub i}) was lower for leaves exposed to 0.2 micropascals per pascal O{sub 3} when compared to the controls, while c{sub i} of the leaves treated with 0.6 micropascals per pascal of O{sub 3} increased during the fumigation. The long-term effects of ambient O{sub 3} and short-term exposure to acute levels of O{sub 3} reduced grape leaf photosynthesis due to a reduction in both stomatal and mesophyll conductances.

Roper, T.R.; Williams, L.E. (Univ. of California, Davis (USA) Kearney Agricultural Center, Parlier, CA (USA))

1989-12-01

110

Association between lifetime ambient ozone exposure and pulmonary function in college freshmen--results of a pilot study.  

Science.gov (United States)

Human health effects due to chronic exposure to ozone (O3) have not been established due to problems with exposure assignment and the use of measures of lung function which may not reflect the site of O3 toxicity in the lung. We investigated the feasibility of retrospective assessment of O3 exposure-relevant covariates and derived lifetime "effective exposure" to ozone. Mid- and end-expiratory flows (FEF25-75%, FEF75%) were regressed against effective exposure and ecological lifetime exposure. A convenience sample of 130 UC Berkeley freshmen, ages 17-21, participated twice in the same tests (residential history, questionnaire, pulmonary function), 5-7 days apart. Students had to be lifelong residents of Northern (SF) or Southern (LA) California. Monthly ambient O3 concentrations (OZ) were assigned based on the lifetime residential history. An "effective time" (T) spent in OZ environments was derived for each residence and age stratum (0-2, 3-5, 6-11, 12+) with the use of questions about "total time spent outdoors" and time spent in "moderate" and/or "heavy" activity. Effective exposure was calculated over the lifetime (OZ x T) of each subject. Ozone metrics used were 8-hr averages (10 AM-6 PM) and "hours above 60 ppb." FEF25-75% and FEF75% decreased with both effective exposure and ecologic assignment of O3 exposure. For a 20 ppb increase (interquartile range) in 8-hr O3, FEF75% decreased 334 ml/sec (95%Cl:11-657 ml/sec), which corresponds to 14% (1.0-28.3%) of the population mean FEF75%. The corresponding effect on FEF25-75% was -420 ml/sec (95%Cl: +46 to -886, P = 0.08) or 7.2% of the mean. Use of time-activity data to define exposure had no impact on estimates. Negative confounding factors were region (SF vs LA), gender, and ethnicity. Lifetime 8-hr average O3 concentrations ranged from 16 to 74 ppb with little overlap between regions. There was no evidence for different O3 effects across regions. Effects were independent of lifetime mean PM10, NO2, temperature, or humidity. Effects on FEV1 tended to be negative whereas those for FVC, although negative in some models, where inconsistent and small. The strong relationship of lifetime ambient O3 on mid- and end-expiratory flows of college freshmen and the lack of association with FEV1 and FVC are consistent with biologic models of chronic effects of O3 in the small airways. Since the present study was designed as a pilot study, these findings have to be confirmed in a larger sample that is representative of the target population. PMID:9012368

Künzli, N; Lurmann, F; Segal, M; Ngo, L; Balmes, J; Tager, I B

1997-01-01

111

The effects of tropospheric ozone and elevated carbon dioxide on potato (Solanum tuberosum L. cv. Bintje) growth and yield.  

Science.gov (United States)

An open-top chamber experiment with field grown potato (Solanum tuberosum L. cv. Bintje) was performed in the south-west of Sweden in 1998. The experiment was aimed to investigate individual and interactive impacts of elevated ozone (O(3)) and carbon dioxide (CO(2)) on potato growth and yield. Treatments were ambient and elevated CO(2) with or without the addition of 20 nmol mol(-1) O(3). In addition, plants were grown in ambient air plots. Plants grown in elevated CO(2) and O(3) had a reduced tuber yield, compared to control, by 2% and 8%, respectively. These effects were, however, not statistically significant. Elevated CO(2) caused a significantly larger number of tubers of lower average size, while elevated O(3) induced significantly lower tuber dry matter content. The number of tuber initials (tubers <15 mm) found at harvest was significantly lower in elevated O(3). Visible O(3) leaf injury appeared earlier and the number of yellow leaves 89 days after emergence was significantly larger in elevated O(3). In elevated CO(2), haulm dry weight was significantly (15%) lower at harvest and the haulm/tuber ratio was significantly reduced. There were significant interactive effects of O(3) and CO(2) on the final number of leaves and on stem height. Plants in elevated CO(2) reached final stem height earlier than in the other treatments. In summary, it was concluded: (a) that anticipated future O(3) levels are likely to have a negative impact on potato growth, although tuber yield effects may be hard to demonstrate experimentally in this plant due to large variation; (b) that whether any possible beneficial effect of elevated CO(2) on the magnitude of tuber yield will be expressed, depend on the climatic conditions prevailing; and (c) that potato growth responses to CO(2) and O(3) are not simply additive. PMID:12812743

Persson, K; Danielsson, H; Selldén, G; Pleijel, H

2003-07-01

112

Modulation of ozone toxicity with changes in ambient temperature in the unanesthetized, unrestrained rat  

Energy Technology Data Exchange (ETDEWEB)

Previous studies from this laboratory have demonstrated an attenuating effect of moderate decreases in body core temperature (T{sub co}) on the toxic response to xenobiotic agents. This study examined an additional modulating effect induced by changes in ambient temperature (T{sub a}). Male Fischer 344 rats were implanted with radiometry transmitters that permitted continuous monitoring of T{sub co}, activity, and electrocardiogram (ECG); heart rate (HR) was derived from the ECG signal. Animals were divided into nine treatment groups and continuously exposed to one of three concentrations of O{sub 3} for 48 hrs while maintained at one of three T{sub a}'s. O{sub 3} exposure led to hypothermia and bradycardia at all three T{sub a}'s. Decreases in T{sub co} and HR ranged from 1.5C and 75 bpm in the high T{sub a} group to 6.1C and 250 bpm in the low T{sub a} group. The only lethalities occurred in the high O{sub 3}-low T{sub a} group. Following O{sub 3} exposure, rats were anesthetized with urethane, intubated, and their lungs were lavaged with warm saline. The number of cells/ml in lavage fluid increased proportionally with decreases in T{sub a} and increases in O{sub 3} concentration. Cellular debris and the ratio of white cells/alveolar macrophages increased with increases in O{sub 3}. These results demonstrate the profound impact of T{sub a} on T{sub co} and the subsequent toxic response in the conscious, unrestrained rat exposed to O{sub 3}.

Watkinson, W.P.; Wiester, M.J. (Environmental Protection Agency, Research Triangle Park, NC (United States))

1991-03-15

113

EFFECTS OF ACIDITY OF SIMULATED RAIN AND ITS JOINT ACTION WITH AMBIENT OZONE ON MEASURES OF BIOMASS AND YIELD IN SOYBEAN  

Science.gov (United States)

An experiment was performed to determine whether the presence of ozone modified the effects of acidity of simulated rain on growth and yield of soybean. Beeson, a type II cultivar, was grown in field chambers and exposed to simulated rain at 3 levels of acidity. Each level was ap...

114

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

115

Growth of EuBa 2Cu 3O 7- ? films under an ozone atmosphere  

Science.gov (United States)

We have investigated the dependence of the crystallinity and the superconducting characteristics in the EuBa 2Cu 3O 7- ? (EuBCO) thin films on oxygen content. The EuBCO films were grown using a pulsed laser deposition (PLD) under an oxygen and an ozone atmosphere on (1 0 0) SrTiO 3 substrates. The c-axis length of as-grown EuBCO films under the oxygen atmosphere was longer than that of the bulk. The c-axis length of in situ annealed EuBCO films was shortened as compared with the as-grown EuBCO films. Additionally, the surface resistance ( Rs) of the in situ 3 and 6 h annealed EuBCO films was lower than that of as-grown EuBCO films. However, the surface resistance of in situ annealed more than 24 h EuBCO films was not lower than that of in situ 6 h EuBCO films. The c-axis length of the as-grown EuBCO films grown under an ozone atmosphere showed 1.170 nm. It must be noted that the lowest surface resistance of EuBCO films was obtained by EuBCO films grown under the ozone atmosphere without any in situ annealing. We found that the growth of EuBCO films under the ozone atmosphere was good to dope oxygen in the films.

Miura, M.; Mukaida, M.; Saito, A.; Ichinose, A.; Horii, S.; Kita, R.; Yoshida, Y.; Matsumoto, K.; Koike, K.; Ohshima, S.

2005-10-01

116

Impact of experimentally elevated ozone on seed germination and growth of Russian pine (Pinus sylvestris) and spruce (Picea spp.) provenances.  

Science.gov (United States)

The impact of elevated ozone concentrations on early ontogenetic stages of pine (Pinus sylvestris) and spruce (Picea abies, Picea obovata, P. abies x P. obovata) seedlings originating from different provenances in Russia were studied in the open-field ozone fumigation system located in Kuopio, Finland, over a span of 2 y. The AOT40 value (accumulated ozone dose over the threshold 40 ppb during daylight hours) was 11 ppm hr per growing season, which was 1.4 times higher than the ambient air concentration. The plants were measured for germination rate; shoot increment; needle length; and dry mass of needles, shoots, and roots. Significant differences between pine and spruce provenance response to ozone were found in all parameters. Ozone stress immediately reduced the germination rate of Northern pine provenances, whereas biomass reductions became evident during the second year of the exposure in all pine provenances. Spruce species were more tolerant to elevated ozone concentrations. Our results indicate that seedling development is vulnerable to increasing ozone concentrations and that attention must be paid to the provenance selection. PMID:20175444

Prozherina, Nadezda; Nakvasina, Elena; Oksanen, Elina

2009-12-01

117

The 1996 Paso del Norte Ozone Study: analysis of meteorological and air quality data that influence local ozone concentrations.  

Science.gov (United States)

The 1996 Paso del Norte Ozone Study and subsequent data analyses were implemented to develop an understanding of the chemical and physical processes which lead to high concentrations of ozone in the Paso del Norte study area which includes El Paso County, Texas, Sunland Park, New Mexico, and Ciudad Juárez, Mexico. Both the data and data analysis results are being used to support photochemical grid modeling. El Paso County and Sunland Park fail to meet the National Ambient Air Quality Standard (NAAQS) for ozone, and neighboring Ciudad Juárez fails to meet the Mexican ambient standard for ozone. This paper summarizes the measurement campaigns of the 1996 Paso del Norte Ozone Study and the findings and conclusions that arose from subsequent data analyses. Data analyses showed that high ozone concentrations resulted from a combination of conditions, including high surface temperatures, strong sunlight with few clouds, light surface winds and high concentrations of ozone precursors at ground level in the morning, and slow convective boundary layer (CBL) growth. Synoptic-scale meteorological conditions observed during high ozone episodes included an aloft high-pressure system and aloft warming. Aloft carryover of ozone and ozone precursors did not significantly contribute to high concentrations of ozone at the surface. PMID:11516142

MacDonal, C P; Roberts, P T; Main, H H; Dye, T S; Coe, D L; Yarbrough, J

2001-08-10

118

MODEL FOR PREDICTING THE INFLUENCE OF MOISTURE STRESS ON CROP LOSSES CAUSED BY OZONE  

Science.gov (United States)

Estimates of crop losses caused by ambient ozone are usually based on results from fumigation experiments performed on adequately watered crops. However, drought frequently affects crop growth, and moisture stress has been found to retard the appearance of ozone injury. To evalua...

119

Short- and long-term effects of ambient ozone and fine particulate matter on the respiratory health of chronic obstructive pulmonary disease subjects.  

Science.gov (United States)

To date, no study has evaluated the short- and long-term effects air pollution exposure on emphysematous subjects who have undergone lung volume reduction surgery (LVRS). Data from the National Emphysema Treatment Trial study (1998-2003) included 1,218 subjects, aged 39 to 84. Daily values of ambient fine particulate matter (aerodynamic diameter ozone were obtained. Mixed-effects models tested the association between short- and long-term pollutant concentrations and changes in pulmonary function. Cumulative air pollution exposure was strongly associated with worsened respiratory function and symptoms. Mean PM2.5 was associated with poorer lung function. Lagged exposures were poorly associated with respiratory health outcomes. There were detrimental respiratory and pulmonary effects observed in response to even low levels of ambient air pollutants among study participants. These results are indicative that exposures even below those of air quality standards may still pose significant risks to severe chronic obstructive pulmonary disease (COPD) subjects. PMID:25136856

Kariisa, Mbabazi; Foraker, Randi; Pennell, Michael; Buckley, Timothy; Diaz, Philip; Criner, Gerard J; Wilkins, J R

2015-01-01

120

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

Science.gov (United States)

...ppm), daily maximum 8-hour average. (b) The 8-hour primary...quality monitoring site when the average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to...

2010-07-01

121

ACUTE EFFECTS OF OZONE ON HEART RATE AND BODY TEMPERATURE IN THE UNANESTHETIZED, UNRESTRAINED RAT MAINTAINED AT DIFFERENT AMBIENT TEMPERATURES  

Science.gov (United States)

The present studies were conducted to investigate the concentration-response characteristics of acute ozone (O3) exposure on the cardiovascular and thermoregulatory function of the unanesthetized, unrestrained rat, and to examine the modulating effects produced by changes in ambi...

122

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

123

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

124

Effects of ozone and simulated acid rain on birch seedling growth and formation of ectomycorrhizae.  

Science.gov (United States)

Four-week-old paper birch (Betula papyrifera Marsh.) seedlings, inoculated or non-inoculated with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker & Couch and grown in steamed or non-steamed soil, were exposed to ozone (O(3)) and/or simulated acid rain (SAR). Plants were exposed to O(3) for 7 h per day on 5 days per week for 12 weeks. O(3) concentrations were maintained between 0.06 and 0.08 ppm. SAR was applied 10 min per day on 2 days per week. O(3), SAR, soil regime and mycorrhizal treatment did not significantly affect any of the measured variables. Interactions between O(3) and SAR, SAR and mycorrhizal treatment, soil regime and mycorrhizal treatment and ozone and soil regime had significant effects. Treatment of seedlings with pH 3.5 SAR caused increases in growth which were more apparent in birch exposed to O(3). Mucorrhizal treatment caused increased growth in non-steamed soil, while growth appeared to decrease in steamed soil. Birch seedlings grew much better in steamed soil. The implications of increased growth in steamed soil may demonstrate the importance of looking at the secondary effects of pollutants on soil-borne organisms. PMID:15092618

Keane, K D; Manning, W J

1988-01-01

125

Crack growth in ASME SA-105 grade 2 steel in hydrogen at ambient temperature  

Science.gov (United States)

Cyclic-load crack growth measurements were performed on ASME SA-105 Grade 2 steel specimens exposed to 10,000- and 15,000-psi hydrogen and to 5000-psi helium, all at ambient temperatures. The cyclic-load crack growth rate was found to be faster in high-pressure hydrogen than in helium. Cyclic-load crack growth rates in this steel were not reduced by preloading in air to a stress intensity of 1.5 times the cyclic K sub max in hydrogen. There are indications that holding under load in hydrogen, and loading and unloading in helium retards hydrogen-accelerated cyclic-load crack growth. Cyclic frequency and R (ratio of K sub min/k sub max) were important variables determining crack growth rate. The crack growth rate increased as a logarithm of the cycle duration and decreased with increasing R.

Walter, R. J.

1975-01-01

126

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 publicat-city studies further suggested publication bias.

127

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

OpenAIRE

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

128

Ozone uptake rates of different-sized black cherry trees in high-and low-light environments  

Energy Technology Data Exchange (ETDEWEB)

Ozone uptake of different-sized black cherry trees from high- and low-light environments was calculated from measurements of ambient ozone concentration and stomatal conductance. The objective of the study was to determine how tree size and light conditions may differentially affect ozone exposure and uptake in a tree known to be highly sensitive to injury from ozone. Instantaneous ozone uptake rates were measured to be highest in high-light environment, while low rates of uptake were measured in forest seedlings and saplings in the forest understorey. Ozone uptake was also higher in the sunlit upper crown and lower in the shaded lower crown. The cumulative ozone uptake was lower for open-grown seedlings and saplings than for canopy trees; this was attributed to their indeterminate pattern of growth. It has been suggested that plants of indeterminate growth allocate more resources to replacement of damaged leaves,hence the lower cumulative ozone uptake. 19 refs.

Fredericksen, T. S. [Pennsylvania State Univ., University Park, PA (United States). Environmental Resources Research Inst.; Skelly, J. M.; Steiner, K. C.; Kolb, T. E.; Joyce, B. J. [Pennsylvania State Univ., University Park, PA (United States). School of Forest Resources; Kouterick, K. B.; Savage, J. E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology

1996-12-31

129

Plant and environment interactions: Growth and yield response of commercial bearing-age {open_quote}Casselman{close_quote} plum trees to various ozone partial pressures  

Energy Technology Data Exchange (ETDEWEB)

Nursery stock of plum (Prunus salicina Lindel., cv. Casselman) was planted 1 Apr. 1988 in an experimental orchard at the Univ. of California Kearney Agricultural Center near Fresno, CA. Trees in this study were enclosed in open-top fumigation chambers on 1 May 1989, and exposed to three atmospheric ozone partial pressures (charcoal filtered air, ambient air, and ambient air + ozone) during the 1989 through 1992 growing seasons (typically 1 Apr. - 1 Nov.). A nonchamber treatment plot was used to assess chamber effects on tree performance. This study details the results of the exposures during the initial commercial bearing period (1991 through 1993) in this orchard. The mean 12-h (0800-2000 h Pacific Daylight Time [PDT]) ozone partial pressures during the experimental periods in the charcoal filtered, ambient, ambient + ozone, and nonchamber treatments averaged 0.031, 0.048, 0.091, and 0.056 {mu}Pa Pa{sup {minus}1} in 1991 and 1992, respectively. Fruit number per tree decreased as atmospheric ozone partial pressure increased from the charcoal filtered to ambient + ozone treatment, significantly affecting yield. Yield of plum trees averaged 23.6, 19.8, 13.7, and 17.9 kg tree{sup {minus}1} in 1991 and 1992 in the charcoal filtered, ambient, ambient + ozone, and nonchamber treatments, respectively. Only one out of the five original treatment plots was exposed to ozone treatments during the 1993 growing season. Yield of plum trees in this single replicate in 1993 was reduced by increased atmospheric ozone partial pressure. Yield of plum trees in the four remaining unexposed treatment plots in 1993 was 16.7, 17.9, and 16.0 kg tree{sup {minus}1} in the previous charcoal filtered, ambient, and ambient + ozone treatments respectively. The similarity in yield of the post-chamber treatments indicates that a change in air quality in the current growing season can affect yield of Casselman plum trees. 26 refs., 6 figs., 4 tabs.

Retzlaff, W.A.; Williams, L.E. [Univ. of California, Parlier, CA (United States); DeJong, T.M. [Univ. of California, Davis, CA (United States)

1997-05-01

130

Linking changes in ozone to changes in emissions and meteorology  

International Nuclear Information System (INIS)

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

131

Modeling the numerical relationships between chronic ambient sulphur dioxide exposures and tree growth  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model to determine the long-term adverse effects of sulphur dioxide (SO{sub 2}) on plant growth and productivity was presented. An exponential growth curve model was developed for pine trees from data collected from five sampling locations near a sulphur recovery sour gas processing plant emitting sulphur gases. The model was based on the mean annual basal area increment for 40 trees from each sampling location. The average age of trees at each location was 34-35 years. A multivariate nonlinear polynomial Fourier (MPF) regression model was used which showed the relationship between ambient SO{sub 2} exposures and basal area increment growth in lodgepole jack pine trees in the West Whitecourt study area. The proposed model captured the actual effects of the episodicity of SO{sub 2} exposures on radial tree growth. It was able to assess the effects of changes in ambient SO{sub 2} air quality on incremental tree growth. 26 refs., 2 tabs., 3 figs.

Legge, A.H. [Biosphere Solutions, Calgary, AB (Canada); Nosal, M. [Calgary Univ., AB (Canada); Krupa, S.V. [Minnesota Univ., St. Paul, MN (United States). Dept. of Plant Pathology

1996-04-01

132

The relationship of ambient ozone and PM(2.5) levels and asthma emergency department visits: possible influence of gender and ethnicity.  

Science.gov (United States)

ABSTRACT An investigation of the relationship of air pollution and emergency department (ED) visits for asthma was an opportunity to assess environmental risks for asthma exacerbations in an urban population. A total of 6,979 individuals with a primary discharge diagnosis of asthma presented to 1 of 6 EDs in the Pittsburgh, Pennsylvania, area between 2002 and 2005. Using a case-crossover methodology, which controls for the effects of subject-specific covariates such as gender and race, a 2.5% increase was observed in asthma ED visits for each 10 ppb increase in the 1-hour maximum ozone level on day 2 (odds ratio [OR] = 1.025, p ambient air pollution, or a differential effect of pollution by race. PMID:22524651

Glad, Jo Ann; Brink, LuAnn Lynn; Talbott, Evelyn O; Lee, Pei Chen; Xu, Xiaohui; Saul, Melissa; Rager, Judith

2012-01-01

133

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

134

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

135

Evaluating the response of two high yielding Indian rice cultivars against ambient and elevated levels of ozone by using open top chambers.  

Science.gov (United States)

A continuous increase in the background level of tropospheric ozone (O(3)) has become a major challenge for present and future agricultural productivity at worldwide. Present study was designed to assess the impact of ambient (present) and elevated (future) concentrations of O(3) on two cultivars of Indian rice (Oryza sativa L. cvs Malviya dhan 36 and Shivani). Shoot and root lengths, number of leaves and total leaf area were severely affected by both ambient and elevated concentrations of O(3). Photosynthetic rate, stomatal conductance and photosynthetic efficiency (F(v)/F(m)) were also reduced by O(3) with more drastic effects under elevated levels of O(3). Leaf proteome showed reduction of some major proteins due to O(3). Pollen viability, viable florets plant(-1) and economic yield also showed significant negative impact under O(3)-exposure in both the test cultivars. The experimental findings depict that both the cultivars of rice demonstrate differential response against O(3), and it may help the plant breeders in selection of resistant cultivars for the area having higher concentrations of O(3). PMID:21788100

Sarkar, Abhijit; Agrawal, S B

2012-03-01

136

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

Science.gov (United States)

During the 2013 wintertime Uintah Basin Ozone Study (UBOS13), an autonomous unmanned aerial vehicle (UAV) platform, coupled with an on-board UV ozone monitor, flew several spatial profiles near the location (Horse Pool) of other concentrated measurements by other co-investigators. The airframe, part of the Utah Water Research Laboratory's (UWRL) AggieAir UAV program, consisted of a custom-built, battery-operated plane with and 2.4 m (8 ft) wing span and a 12.7 cm x 12.7 cm x 30.5 cm payload bay with a carrying capacity of approximately 2.0 kg. With the current power system, the fully-loaded AggieAir UAV can fly for approximately 45 minutes at a nominal airspeed of 13.4 m/s (30 mph). The system can be operated either in manual control or be flown autonomously following preprogrammed waypoints via a built in GPS system. The AggieAir UAV systems were primarily designed for photographic and telemetry tracking projects. For the UBOS13 flights, a 2B Technologies Model 205 Ozone (O3) monitor was modified for minimal weight optimization, wrapped with lightweight insulation and secured into the UAV payload bay. Additionally, HOBO Model H08-001-02 shielded temperature/datalogger was secured to the exterior of the UAV from parallel thermal profile determination. During the study period, three demonstration flight profiles were obtained on February 17 and 18, 2013: two vertical 'curtain' profiles and a pair of 'stacked' horizontal profiles. As recorded by numerous ground-based monitoring sites, the ozone during the UAV test periods was characterized by initial trends of daytime O3 maximums over 130 ppb, followed by a meteorological front partially ventilating the Basin on the evening of Feb. 17th leading to decreased O3 minimums around 40 ppb. However, the ground level O3 rebuilt quickly to ground level maximums approaching 100 ppb. The vertical 'curtain' flown on the evening of Feb. 17th only reached a maximum elevation of about 2160 m ASL (600 m AGL) due to encountering upper level excessive winds as the low pressure front approached. However the flight was still able to capture a temperature profile indicating a well-mixed atmosphere below about 300 m AGL, sealed by a definitive inversion layer extending to the top of the measurement profile. The measured O3 profile went from about 140 ppb near the ground to around 60 ppb at the start of the inversion layer, and then remained essentially constant until the top of the elevation profile. The vertical profile late in the morning of the following day (after the front had passed), showed nearly straight vertical profiles of temperature (?2°C) and ozone (35-50 ppb) up to approximately 2400 m ASL (820 m AGL). The stacked horizontal profiles (1650 and 1750 m ASL) flown immediately after the vertical flight of Feb. 17th showed some differences on the horizontal scale, but it was unclear if these differences were associated with terrain differences (topography dropped rapidly to the south) or locational differences in precursor sources. The UAV measured ozone compared favorably to nearby co-investigators (NOAA/ESRL CSD TOPAZ Lidar and CU/INSTAAR tethered balloon).

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

2013-12-01

137

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

Science.gov (United States)

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

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

2014-03-01

138

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

Science.gov (United States)

When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools. PMID:25645061

Khaling, Eliezer; Papazian, Stefano; Poelman, Erik H; Holopainen, Jarmo K; Albrectsen, Benedicte R; Blande, James D

2015-04-01

139

Effects of substrate and ambient gas on epitaxial growth indium oxide thin films  

International Nuclear Information System (INIS)

Indium oxide thin films were grown by pulsed electron beam deposition method at 500 °C on c-cut sapphire and (0 0 1) oriented LaAlO3 single crystal substrates in oxygen or argon gas. The effects of ambient gas and substrate symmetry on the growth of indium oxide thin films were studied. Stoichiometric In2O3 films are formed in oxygen, while oxygen deficient In2O2.5 films are grown in argon, with In metallic nanoclusters embedded in a In2O3 matrix (nanocomposite films). In both cases, epitaxial In2O3 films having the bixbyite phase were grown with various orientation relationships, depending upon the substrate symmetry and gas ambient (oxygen or argon). Domain matching epitaxy was used to describe the precise in-plane epitaxial film–substrate relationships. The differences in film texture were correlated to the differences in growth conditions, while the differences in the film properties were correlated to the film oxygen composition.

140

Effects of substrate and ambient gas on epitaxial growth indium oxide thin films  

Energy Technology Data Exchange (ETDEWEB)

Indium oxide thin films were grown by pulsed electron beam deposition method at 500 °C on c-cut sapphire and (0 0 1) oriented LaAlO{sub 3} single crystal substrates in oxygen or argon gas. The effects of ambient gas and substrate symmetry on the growth of indium oxide thin films were studied. Stoichiometric In{sub 2}O{sub 3} films are formed in oxygen, while oxygen deficient In{sub 2}O{sub 2.5} films are grown in argon, with In metallic nanoclusters embedded in a In{sub 2}O{sub 3} matrix (nanocomposite films). In both cases, epitaxial In{sub 2}O{sub 3} films having the bixbyite phase were grown with various orientation relationships, depending upon the substrate symmetry and gas ambient (oxygen or argon). Domain matching epitaxy was used to describe the precise in-plane epitaxial film–substrate relationships. The differences in film texture were correlated to the differences in growth conditions, while the differences in the film properties were correlated to the film oxygen composition.

Nistor, M. [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), Atomistilor Str. 109, L22 P.O. Box. MG-36, 077125 Bucharest-Magurele (Romania); Seiler, W. [PIMM, UMR CNRS 8006 Arts et Métiers ParisTech, 151 Boulevard de l’Hopital, 75013 Paris (France); Hebert, C. [Sorbonne Universités, UPMC Univ Paris 06, UMR 7588, INSP, F-75005 Paris (France); CNRS, UMR 7588, INSP, F-75005 Paris (France); Matei, E. [National Institute of Materials Physics (NIMP), Atomistilor Str. 105 bis, P.O. Box MG-7, 077125 Magurele-Ilfov (Romania); Perrière, J., E-mail: jacques.perriere@insp.jussieu.fr [Sorbonne Universités, UPMC Univ Paris 06, UMR 7588, INSP, F-75005 Paris (France); CNRS, UMR 7588, INSP, F-75005 Paris (France)

2014-07-01

141

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

Science.gov (United States)

Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 mumol mol-1 CO2) and two ozone concentrations (ambient and an 8 h day-1 seasonal mean of 50 nmol mol-1 O3) between emergence and final harvest. Periodic non-destructive measurements were made and destructive harvests were carried out at three key developmental stages (24, 49 and 101 days after emergence) to establish effects on growth and tuber yield. Season-long exposure to elevated O3 reduced above-ground dry weight at final harvest by 8.4% (P < 0.05), but did not affect tuber yields. There was no significant interaction between CO2 and O3 for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO2 on plant height, leaf number or green leaf area ratio. However, destructive harvests at tuber initiation and 500 degrees 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 mumol mol-1 CO2 treatment. Responses to 550 and 680 mumol mol-1 CO2 were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO2 enrichment. Significant effects on above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P < 0.05) under elevated CO2, particularly in the smaller size categories. The results show that the O3 treatment imposed was insufficient to reduce tuber yields and that, although elevated CO2 enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. PMID:11202753

Lawson, T; Craigon, J; Black, C R; Colls, J J; Tulloch, A M; Landon, G

2001-01-01

142

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

International Nuclear Information System (INIS)

Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 ?mol mol-1 CO2) and two ozone concentrations (ambient and an 8 h day -1 seasonal mean of 50 nmol mol-1 O3) between emergence and final harvest. Periodic non-destructive measurements were made and destructive harvests were carried out at three key developmental stages (24, 49 and 101 days after emergence) to establish effects on growth and tuber yield. Season-long exposure to elevated O3 reduced above-ground dry weight at final harvest by 8.4% (P2 and O3 for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO2 on plant height, leaf number or green leaf area ratio. However, destructive harvests at tuber initiation and 500 deg Cd after emergence showed that above-ground dry weight (8 and 7% respectively) and tuber yield (88 and 44%) were significantly increased (P-1 CO2 treatment. Responses to 550 and 680 ?mol mol-1 CO2 were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO2 enrichment. Significant effects2 enrichment. Significant effects on the above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P2, particularly in the smaller size categories. The results show that the O3 treatment imposed was insufficient to reduce tuber yields and that, although elevated CO2 enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. (Author)

143

Growth rates of nucleation mode particles in Hyytiälä during 2003?2009: variation with particle size, season, data analysis method and ambient conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the lifetime of these particles and their ability to become climatically relevant. Diameter growth rates (GR of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS, a Balanced Scanning Mobility Analyzer (BSMA and an Air Ion Spectrometer (AIS. Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5–3 nm, 3–7 nm and 7–20 nm were 1.9 nm h?1, 3.8 nm h?1, and 4.3 nm h?1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25%, 19%, and 8%, respectively. For the smallest particles (1.5–3 nm the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the uncertainty in the growth rate related to the analysis method, with relative uncertainty of 16%, was similar to that related to the instruments. The growth rates of 7–20 nm particles showed positive correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations of organic precursors.

M. Kulmala

2011-12-01

144

Nucleation mode growth rates in Hyytiälä during 2003–2009: variation with particle size, season, data analysis method and ambient conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the life time of these particles and their ability to become climatically relevant. Diameter growth rates (GR of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS, a Balanced Scanning Mobility Analyser (BSMA and an Air Ion Spectrometer (AIS. Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5–3 nm, 3–7 nm and 7–20 nm were 1.9 nm h?1, 3.8 nm h?1, and 4.3 nm h?1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25 %, 19 %, and 8 %, respectively. For the smallest particles (1.5–3 nm the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the main uncertainty of the growth rate was related to the analysis method, as the values obtained with the two methods had a median difference of 35 %. The growth rates of 7–20 nm particles showed correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations and O3-oxidation of organic precursors.

T. Yli-Juuti

2011-07-01

145

Nucleation mode growth rates in Hyytiälä during 2003-2009: variation with particle size, season, data analysis method and ambient conditions  

Science.gov (United States)

The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the life time of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003-2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS), a Balanced Scanning Mobility Analyser (BSMA) and an Air Ion Spectrometer (AIS). Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5-3 nm, 3-7 nm and 7-20 nm were 1.9 nm h-1, 3.8 nm h-1, and 4.3 nm h-1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25 %, 19 %, and 8 %, respectively. For the smallest particles (1.5-3 nm) the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the main uncertainty of the growth rate was related to the analysis method, as the values obtained with the two methods had a median difference of 35 %. The growth rates of 7-20 nm particles showed correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations and O3-oxidation of organic precursors.

Yli-Juuti, T.; Nieminen, T.; Hirsikko, A.; Aalto, P. P.; Asmi, E.; Hõrrak, U.; Manninen, H. E.; Patokoski, J.; Dal Maso, M.; Petäjä, T.; Rinne, J.; Kulmala, M.; Riipinen, I.

2011-07-01

146

Growth rates of nucleation mode particles in Hyytiälä during 2003-2009: variation with particle size, season, data analysis method and ambient conditions  

Science.gov (United States)

The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the lifetime of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003-2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS), a Balanced Scanning Mobility Analyzer (BSMA) and an Air Ion Spectrometer (AIS). Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5-3 nm, 3-7 nm and 7-20 nm were 1.9 nm h-1, 3.8 nm h-1, and 4.3 nm h-1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25%, 19%, and 8%, respectively. For the smallest particles (1.5-3 nm) the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the uncertainty in the growth rate related to the analysis method, with relative uncertainty of 16%, was similar to that related to the instruments. The growth rates of 7-20 nm particles showed positive correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations of organic precursors.

Yli-Juuti, T.; Nieminen, T.; Hirsikko, A.; Aalto, P. P.; Asmi, E.; Hõrrak, U.; Manninen, H. E.; Patokoski, J.; Dal Maso, M.; Petäjä, T.; Rinne, J.; Kulmala, M.; Riipinen, I.

2011-12-01

147

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

Energy Technology Data Exchange (ETDEWEB)

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

Uzueli, Daniel Henrique

2013-07-01

148

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.

149

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

Science.gov (United States)

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

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

2011-12-01

150

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

151

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-07-15

152

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

International Nuclear Information System (INIS)

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

153

Evaluation and calibration of Aeroqual series 500 portable gas sensors for accurate measurement of ambient ozone and nitrogen dioxide  

Science.gov (United States)

Low-power, and relatively low-cost, gas sensors have potential to improve understanding of intra-urban air pollution variation by enabling data capture over wider networks than is possible with 'traditional' reference analysers. We evaluated an Aeroqual Ltd. Series 500 semiconducting metal oxide O3 and an electrochemical NO2 sensor against UK national network reference analysers for more than 2 months at an urban background site in central Edinburgh. Hourly-average Aeroqual O3 sensor observations were highly correlated (R2 = 0.91) and of similar magnitude to observations from the UV-absorption reference O3 analyser. The Aeroqual NO2 sensor observations correlated poorly with the reference chemiluminescence NO2 analyser (R2 = 0.02), but the deviations between Aeroqual and reference analyser values ([NO2]Aeroq - [NO2]ref) were highly significantly correlated with concurrent Aeroqual O3 sensor observations [O3]Aeroq. This permitted effective linear calibration of the [NO2]Aeroq data, evaluated using 'hold out' subsets of the data (R2 ? 0.85). These field observations under temperate environmental conditions suggest that the Aeroqual Series 500 NO2 and O3 monitors have good potential to be useful ambient air monitoring instruments in urban environments provided that the O3 and NO2 gas sensors are calibrated against reference analysers and deployed in parallel.

Lin, C.; Gillespie, J.; Schuder, M. D.; Duberstein, W.; Beverland, I. J.; Heal, M. R.

2015-01-01

154

Ozone/biotic disease interactions: molecular biomarkers as a new experimental tool.  

Science.gov (United States)

Current climate change scenarios predict a further increase of tropospheric ozone which is well known to inhibit plant photosynthesis and growth processes. Ozone can also predispose plants to enhanced biotic attack, as proposed in particular for necrotrophic fungi, root-rot fungi and bark beetles. However, at present it does not seem possible to predict whether increased ambient ozone will lead to a higher or lower disease likelihood in particular plant-pathogen systems. It has been stated repeatedly in the literature that periods of high ambient ozone are essentially non-coincident with infection periods of most fungal pathogens. This implies minimal interactive risks. However, it now appears that the various ozone-induced metabolic changes can persist in plants over days or months. Visible ozone symptoms also may be greatly delayed. Certain stress transcripts, proteins and metabolites have been developed as ozone biomarkers in controlled exposure experiments, but these biomarkers remain to be examined on field sites. A simple epidemiological scenario based on 'memory' time spans of ozone effects is proposed as a tool to make ozone-plant disease interactions more predictable. PMID:15092927

Sandermann, H

2000-06-01

155

Effects of salinity and ozone, individually and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties  

International Nuclear Information System (INIS)

Plants exposed to ozone, under high salinity conditions, further decline in growth. - The aim of this study was to determine the effects of ozone and salinity, singly and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties. Chickpea plants were grown in non-saline and saline conditions, with and without a repeated exposure to ozone. Salinity at a concentration of 30 mM NaCl caused a substantial reduction in plant height, number of leaves and the dry weights of the leaves, stems and roots. Biomass allocation to the leaves increased, predominantly at the expense of the roots. Ozone at a concentration of 85 nmol mol-1 for 6 h per day for 25 days reduced plant height and dry weights but had no effect on leaf number. The results show substantial effects of salinity and ozone on chickpea growth and ion concentrations. When ozonated plants are grown in the presence of salinity, further reductions in growth occur

156

Effects of salinity and ozone, individually and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties  

Energy Technology Data Exchange (ETDEWEB)

Plants exposed to ozone, under high salinity conditions, further decline in growth. - The aim of this study was to determine the effects of ozone and salinity, singly and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties. Chickpea plants were grown in non-saline and saline conditions, with and without a repeated exposure to ozone. Salinity at a concentration of 30 mM NaCl caused a substantial reduction in plant height, number of leaves and the dry weights of the leaves, stems and roots. Biomass allocation to the leaves increased, predominantly at the expense of the roots. Ozone at a concentration of 85 nmol mol{sup -1} for 6 h per day for 25 days reduced plant height and dry weights but had no effect on leaf number. The results show substantial effects of salinity and ozone on chickpea growth and ion concentrations. When ozonated plants are grown in the presence of salinity, further reductions in growth occur.

Welfare, Karen; Yeo, A.R.; Flowers, T.J

2002-12-01

157

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

158

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

Science.gov (United States)

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

Spruce, Joseph P.

2007-01-01

159

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-03-01

160

Tropospheric ozone increases over the southern Africa region: bellwether for rapid growth in Southern Hemisphere pollution?  

Science.gov (United States)

Increases in free-tropospheric (FT) ozone based on ozonesonde records from the early 1990s through 2008 over two subtropical stations, Irene (near Pretoria, South Africa) and Réunion (21° S, 55° E; ~2800 km NE of Irene in the Indian Ocean), have been reported. Over Irene a large increase in the urban-influenced boundary layer (BL, 1.5-4 km) was also observed during the 18-year period, equivalent to 30% decade-1. Here we show that the Irene BL trend is at least partly due to a gradual change in the sonde launch times from early morning to the midday period. The FT ozone profiles over Irene in 1990-2007 are re-examined, filling in a 1995-1999 gap with ozone profiles taken during the Measurements of Ozone by Airbus In-service Aircraft (MOZAIC) project over nearby Johannesburg. A multivariate regression model that accounts for the annual ozone cycle, El Niño-Southern Oscillation (ENSO) and possible tropopause changes was applied to monthly averaged Irene data from 4 to 11 km and to 1992-2011 Réunion sonde data from 4 to 15 km. Statistically significant trends appear predominantly in the middle and upper troposphere (UT; 4-11 km over Irene, 4-15 km over Réunion) in winter (June-August), with increases ~1 ppbv yr-1 over Irene and ~2 ppbv yr-1 over Réunion. These changes are equivalent to ~25 and 35-45% decade-1, respectively. Both stations also display smaller positive trends in summer, with a 45% decade-1 ozone increase near the tropopause over Réunion in December. To explain the ozone increases, we investigated a time series of dynamical markers, e.g., potential vorticity (PV) at 330-350 K. PV affects UT ozone over Irene in November-December but displays little relationship with ozone over Réunion. A more likely reason for wintertime FT ozone increases over Irene and Réunion appears to be long-range transport of growing pollution in the Southern Hemisphere. The ozone increases are consistent with trajectory origins of air parcels sampled by the sondes and with recent NOx emissions trends estimated for Africa, South America and Madagascar. For Réunion trajectories also point to sources from the eastern Indian Ocean and Asia.

Thompson, A. M.; Balashov, N. V.; Witte, J. C.; Coetzee, J. G. R.; Thouret, V.; Posny, F.

2014-09-01

161

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

Science.gov (United States)

Plant functional type (PFT) distributions affect the results of biogenic emission modeling as well as O3 and particulate matter (PM) simulations using chemistry-transport models (CTMs). This paper analyzes the variations of both surface biogenic volatile organic compound (BVOC) emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. The Fifth-Generation NCAR/Pennsylvania State Meso-scale Model (MM5)/the Model of Emissions of Gases and Aerosols from Nature (MEGAN)/the Sparse Matrix Operator Kernel Emissions (SMOKE)/the Community Multiscale Air Quality (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 a performance check of CTM predictions, we consecutively assessed the effects of PFT area deviations on the MEGAN BVOC and CTM O3 predictions, and we further considered the basis of geospatial and statistical analyses. The three PFT data sets considered were (1) the Korean PFT, developed with Korea-specific vegetation database; (2) the CDP PFT, adopted from the community data portal (CDP) of US National Center for Atmospheric Research in the United States (NCAR); (3) MODIS PFT, reclassified from the NASA Terra and Aqua combined land cover products. Although the CMAQ performance check reveals that all of the three different PFT data sets are applicable choices for regulatory modeling practice, noticeable primary data (i.e., PFT and Leaf Area Index (LAI)) was observed to be missing in many geographic locations. Based on the assessed effect of such missing data on CMAQ O3 predictions, we found that this missing data can cause spatially increased bias in CMAQ O3. Thus, it must be resolved in the near future to obtain more accurate biogenic emission and chemistry transport modeling results. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BTs) are the most significant contributor, followed by needleleaf trees (NTs), shrub (SB), and herbaceous plants (HBs) to the total BVOCs. In addition, isoprene from BTs and terpene from NTs were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. A geographically weighted regression analysis with locally compensated ridge (LCR-GWR) with the different PFT data (?O3 vs. ?PFTs) suggests that addition of BT, SB, and NT areas can contribute to O3 increase, whereas addition of an HB area contributes to O3 decrease in the domain. Assessment results of the simulated spatial and temporal changes of O3 distributions with the different PFT scenarios reveal that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 13 ppb. The simulated maximum 1 h O3 inter-deviations between different PFT scenarios have an asymmetric diurnal distribution pattern (low in the early morning, rising during the day, peaking at 05:00 p.m., and decreasing during the night) in the study domain. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of different PFT distribution data requires much caution when modeling (or forecasting) O3 air quality in complicated urban atmospheric conditions in terms of whether uncertainties in O3 prediction results are expected to be mild or severe.

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

2014-07-01

162

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

163

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-02-15

164

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

165

Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis Mill. when subject to ozone stress  

OpenAIRE

We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable...

Incla?n, R.; Gimeno, B. S.; Pen?uelas, Josep; Gerant, D.; Quejido, A.

2011-01-01

166

Role of Nerve Growth Factor in Ozone-Induced Neural Responses in Early Postnatal Airway Development  

Science.gov (United States)

Airway neural plasticity contributes to the process of airway remodeling in response to airway irritants. However, the mechanisms of neural remodeling in the airways during the early postnatal period, when responses to airway irritation may be most sensitive, have not been characterized. This study used a rat model to examine a possible mechanism of ozone (O3)-induced neural hyperresponsiveness during a critical period of developmental, postnatal day (PD) 6, that may be mediated by the neurotrophin nerve growth factor (NGF), resulting in an enhanced release of inflammatory neuropeptide substance P (SP) from airway nerves. Rat pups between PD6–PD28 were killed 24 hours after exposure to O3 (2 ppm, 3 hours) or filtered air (FA), to establish a timeline of NGF synthesis, or else they were exposed to O3 or NGF on PD6 or PD21 and re-exposed to O3 on PD28, and killed on PD29. Measurement endpoints included NGF mRNA in tracheal epithelial cells, NGF protein in bronchoalveolar lavage fluid, airway SP–nerve fiber density (NFD), and SP-positive airway neurons in vagal ganglia. Acute exposure to O3 increased NGF in bronchoalveolar lavage fluid on PD10 and PD15, and mRNA expression in epithelial cells on PD6, compared with FA controls. NGF protein and mRNA expression in the O3–PD6/O3–PD28 groups were significantly higher than in the O3–PD21/O3–PD28 and O3–PD6/FA–PD28 groups. NGF–PD6/O3–PD28 increased the SP innervation of airway smooth muscle and SP-positive sensory neurons, compared with the NGF–PD21/O3–PD28 or NGF–PD6/FA–PD28 groups. NGF enhanced sensory innervation, which may mediate acute responses or prolong sensitivity to O3 during early life. The model may be relevant in O3 responses during early childhood. PMID:21075861

Hunter, Dawn D.; Carrell-Jacks, Lynnsey A.; Batchelor, Tom P.; Dey, Richard D.

2011-01-01

167

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

168

Real-time instrument for ambient monitoring of hydrogen sulfide, dimethyl sulfide, and other reduced organosulfur species using ozone chemiluminescent detection  

Energy Technology Data Exchange (ETDEWEB)

The chemiluminescent reactions of H/sup 2/S and other gaseous sulfides with ozone at 298/sup 0/K have been investigated, with the aim of developing a simple, selective, real-time monitor for these naturally emitted compounds. A commercial chemiluminescent ozone monitor has been adapted, for detection of the ozone/sulfide chemiluminescence between 300 and 400 nm wavelenght. Excess ozone was supplied to the reaction chamber from an electrical discharge ozone source. Response to dimethyl sulfide was enhanced by the use of air in the ozone source rather than oxygen. This effect was found to be caused by the presence of oxides of nitrogen produced in the ozonizer; a similar enhancement was not observed for the other sulfide compounds studied. Observed chemiluminescence signal decreased in the order CH/sub 3/SH > CH/sub 3/SCH/sub 3/ > H/sub 2/S > thiophene, with detection limits of 0.1, 0.3, 4, and 12 ppb respectively, at an instrument time constant of 60 sec. Calibration plots were linear at low sulfide concentrations, and showed less-than-first order dependence on sulfide at higher concentrations. A very small signal from ethylene was the only interference found from several compounds tested; sample air humidity has a small but significant effect on the instrument response.

Kelly, T. J.; Phillips, M. F.; Tanner, R. L.; Gaffney, J. S.

1982-01-01

169

Epithelial injury and interstitial fibrosis in the proximal alveolar regions of rats chronically exposed to a simulated pattern of urban ambient ozone.  

Science.gov (United States)

Electron microscopic morphometry was used to study the development of lung injury during and after chronic (78 weeks) exposure to a pattern of ozone (O3) designed to simulate high urban ambient concentrations that occur in some environments. The daily exposure regimen consisted of a 13-hr background of 0.06 ppm, an exposure peak that rose from 0.06 to 0.25 ppm, and returned to the background level over a 9-hr period, and 2-hr downtime for maintenance. Rats were exposed for 1, 3, 13, and 78 weeks. Additional groups of rats exposed for 13 or 78 weeks were allowed to recover in filtered clean air for 6 or 17 weeks, respectively. Rats exposed to filtered air for the same lengths of time were used as controls. Samples from proximal alveolar regions and terminal bronchioles were obtained by microdissection. Analysis of the proximal alveolar region revealed a biphasic response. Acute tissue reactions after 1 week of exposure included epithelial inflammation, interstitial edema, interstitial cell hypertrophy, and influx of macrophages. These responses subsided after 3 weeks of exposure. Progressive epithelial and interstitial tissue responses developed with prolonged exposure and included epithelial hyperplasia, fibroblast proliferation, and interstitial matrix accumulation. The epithelial responses involved both type I and type II epithelial cells. Alveolar type I cells increased in number, became thicker, and covered a smaller average surface area. These changes persisted throughout the entire exposure and did not change during the recovery period, indicating the sensitivity of these cells to injury. The main response of type II epithelial cells was cell proliferation. The accumulation of interstitial matrix after chronic exposure consisted of deposition of both increased amounts of basement membrane and collagen fibers. Interstitial matrix accumulation underwent partial recovery during follow-up periods in air; however, the thickening of the basement membrane did not resolve. Analysis of terminal bronchioles showed that short-term exposure to O3 caused a loss of ciliated cells and differentiation of preciliated and Clara cells. The bronchiolar cell population stabilized on continued exposure; however, chronic exposure resulted in structural changes, suggesting injury to both ciliated and Clara cells. We conclude that chronic exposure to low levels of O3 causes epithelial inflammation and interstitial fibrosis in the proximal alveolar region and bronchiolar epithelial cell injury. PMID:1641858

Chang, L Y; Huang, Y; Stockstill, B L; Graham, J A; Grose, E C; Menache, M G; Miller, F J; Costa, D L; Crapo, J D

1992-08-01

170

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...

171

Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide  

International Nuclear Information System (INIS)

In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests

172

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

Science.gov (United States)

...for Ozone 1. General This appendix...contained in the “Guideline for Interpretation...for incomplete sampling. In general, the average...for incomplete sampling. The term “missing...used here in the general sense...

2010-07-01

173

Ozone Pollution  

Medline Plus

Full Text Available ... Report Card Widget Or Enter Your Zip Code: Ozone Pollution More than 4 in 10 people in ... areas with unhealthful levels of ozone. What Is Ozone? Ozone is a molecule of three oxygen atoms. ...

174

Bioassaying for ozone with pollen systems.  

OpenAIRE

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. Tube growth rates in the presence of a range of ozone dosages, of pollen populations exhibiting differing ozone sensitivity can be measured and different grow...

Feder, W. A.

1981-01-01

175

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

176

Role of Nerve Growth Factor in Ozone-Induced Neural Responses in Early Postnatal Airway Development  

OpenAIRE

Airway neural plasticity contributes to the process of airway remodeling in response to airway irritants. However, the mechanisms of neural remodeling in the airways during the early postnatal period, when responses to airway irritation may be most sensitive, have not been characterized. This study used a rat model to examine a possible mechanism of ozone (O3)-induced neural hyperresponsiveness during a critical period of developmental, postnatal day (PD) 6, that may be mediated by the neurot...

Hunter, Dawn D.; Carrell-jacks, Lynnsey A.; Batchelor, Tom P.; Dey, Richard D.

2011-01-01

177

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

OpenAIRE

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 activity and strongly induce...

Laila Ezzel-Arab Abdel Nasser

2002-01-01

178

Ozone measurement systems: associated instrumentation and calibration  

OpenAIRE

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 instrume...

Bellido, J.

2006-01-01

179

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

OpenAIRE

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 cont...

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

2014-01-01

180

Growth of catalyst-free high-quality ZnO nanowires by thermal evaporation under air ambient  

OpenAIRE

ZnO nanowires have been successfully fabricated on Si substrate by simple thermal evaporation of Zn powder under air ambient without any catalyst. Morphology and structure analyses indicated that ZnO nanowires had high purity and perfect crystallinity. The diameter of ZnO nanowires was 40 to 100 nm, and the length was about several tens of micrometers. The prepared ZnO nanowires exhibited a hexagonal wurtzite crystal structure. The growth of the ZnO nanostructure was explained by the vapor-so...

Liu, Ping; Li, Yanbin; Guo, Yanqing; Zhang, Zhenhua

2012-01-01

181

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

Science.gov (United States)

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production. PMID:24086640

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

2013-01-01

182

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. PMID:24018831

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

2013-01-01

183

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. PMID:24018831

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

2013-01-01

184

Chronic exposure of Rutilus rutilus caspicus fingerlings to ambient copper: Effects on food intake, growth performance, biochemistry and stress resistance.  

Science.gov (United States)

An 8-week trial was conducted to investigate the effect of ambient copper (Cu) on growth performance, physiological characteristics and stress resistance of Caspian roach, Rutilus rutilus caspicus. Fish were exposed to 0 (control), 0.02, 0.04 and 0.06 ppm Cu, and their food intake and growth performance were fortnightly recorded. Also, serum cortisol, glucose, alanine aminotransferase (ALT) and sodium (Na) levels were determined after 2 and 8 weeks exposure to ambient Cu. At the end of trial, serum total protein, albumin, globulin and albumin-globulin ratio (A:G) levels, whole body proximate composition and stress tolerance of the fish were measured. Results showed that Cu exposure resulted in a significant suppression in food intake after 2 weeks, which was eliminated after 4 weeks in 0.02 ppm groups and after 6 weeks in 0.04 and 0.06 ppm groups. Cu exposure brought about an inferior growth that recovered in line with the experiment progression, following a dose-dependent manner. Cu-exposed fish showed a dose-dependent increase in serum cortisol, glucose and ALT as well as decrease in serum Na, after 2 weeks. These parameters showed a full recovery in 0.02 ppm group and a partial recovery in 0.04 and 0.06 ppm groups, at the 8th week. Significant suppression in serum total protein, albumin, globulin and A:G levels and whole body dry matter, lipid and protein levels as well as stress resistance was observed in 0.04 and 0.06 ppm groups. It is concluded that Cu exposure could adversely affect growth performance, physiological characteristics and stress resistance of Caspian roach, which might affect its ecological features. PMID:24105068

Hoseini, Seyyed Morteza; Rajabiesterabadi, Hamid; Kordrostami, Sara

2013-10-01

185

MEASUREMENTS OF THE PRODUCTS OF ATMOSPHERIC PHOTOCHEMICAL REACTIONS IN LABORATORY STUDIES AND IN AMBIENT AIR-RELATIONSHIPS BETWEEN OZONE AND OTHER PRODUCTS  

Science.gov (United States)

Many inorganic and organic gaseous and aerosol products are formed in the atmosphere from atmospheric photochemical reactions. The mechanisms of formation, types of products identified, smog chamber studies, and ambient air concentrations and distributions are considered in this ...

186

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

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

2014-09-01

187

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 ...

188

Ozone Pollution  

Medline Plus

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 ...

189

Ozone Pollution  

Medline Plus

Full Text Available ... for ozone levels. These people live where the monitored air quality places them at risk for premature ... frequent high ozone days. Sunlight and heat create conditions that increase the risk of high ozone levels. ...

190

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

191

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

192

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

193

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

194

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

195

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 + O3); and charcoal-filtered air with addition of doubled concentrations of ozone (CF + 2 x O3). 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 O3 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.)

196

Biaxial Fatigue Crack Growth Behavior in Aluminum Alloy 5083-H116 Under Ambient Laboratory and Saltwater Environments  

Science.gov (United States)

Crack growth of aluminum alloy 5083 was investigated when subjected to the in-plane biaxial tension-tension fatigue with stress ratio of 0.5 under ambient laboratory and saltwater environments. Cruciform specimens with a center hole, containing a notch and precrack at 45° to the specimen's arms, were tested in a biaxial fatigue test machine. Two biaxiality ratios, ? = 1 and ? = 1.5, were studied. For ? = 1, crack propagated along a straight line collinearly with the precrack, while for ? = 1.5 case, the crack path was curved and non-collinear with the precrack. Uniaxial fatigue tests were also conducted. Crack growth rates were faster under the biaxiality fatigue in comparison to uniaxial fatigue at a given crack driving force (?K I or ?G) in both environments. Further, an increase in biaxiality ratio increased the crack growth rate, i.e., faster for ? = 1.5 case than ? = 1 case. Both biaxial fatigue and saltwater environment showed detrimental effects on the fatigue crack growth resistance of 5083, and its combination is highly detrimental when compared to uniaxial fatigue.

Perel, V. Y.; Misak, H. E.; Mall, S.; Jain, V. K.

2015-02-01

197

Biaxial Fatigue Crack Growth Behavior in Aluminum Alloy 5083-H116 Under Ambient Laboratory and Saltwater Environments  

Science.gov (United States)

Crack growth of aluminum alloy 5083 was investigated when subjected to the in-plane biaxial tension-tension fatigue with stress ratio of 0.5 under ambient laboratory and saltwater environments. Cruciform specimens with a center hole, containing a notch and precrack at 45° to the specimen's arms, were tested in a biaxial fatigue test machine. Two biaxiality ratios, ? = 1 and ? = 1.5, were studied. For ? = 1, crack propagated along a straight line collinearly with the precrack, while for ? = 1.5 case, the crack path was curved and non-collinear with the precrack. Uniaxial fatigue tests were also conducted. Crack growth rates were faster under the biaxiality fatigue in comparison to uniaxial fatigue at a given crack driving force (? K I or ? G) in both environments. Further, an increase in biaxiality ratio increased the crack growth rate, i.e., faster for ? = 1.5 case than ? = 1 case. Both biaxial fatigue and saltwater environment showed detrimental effects on the fatigue crack growth resistance of 5083, and its combination is highly detrimental when compared to uniaxial fatigue.

Perel, V. Y.; Misak, H. E.; Mall, S.; Jain, V. K.

2015-04-01

198

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

199

Foliar injury, leaf gas exchange and biomass responses of black cherry (Prunus serotina Ehrh.) half-sibling families to ozone exposure.  

Science.gov (United States)

Open pollinated families of black cherry seedlings were studied to determine genotypic differences in foliar ozone injury and leaf gas exchange in 1994 and growth response following three growing seasons. An O(3)-sensitive half-sibling family (R-12) and an O(3)-tolerant half-sibling family (MO-7) planted in natural soil were studied along with generic nursery stock (NS) seedlings. Ozone exposure treatments were provided through open top chambers and consisted of 50, 75, and 97% of ambient ozone, and open plots from May 9 to August 26, 1994. Ambient ozone concentrations reached an hourly peak of 88 ppb with 7-hour averages ranging from 39 to 46 ppb. Seedlings in the 50 and 75% of ambient chambers were never exposed to greater than 80 ppb O(3). Visible foliar ozone injury (stipple) was significantly higher for R-12 seedlings than MO-7 seedlings and increased with increasing ozone exposures. For the chamber treatments averaged over all families, there was no significant difference in stomatal conductance and net photosynthetic rates, but there was a significant decrease in root biomass, and a significant decrease in root/shoot ratio between the 50 and 97% of ambient chambers. Stomatal conductance and net photosynthetic rates were significantly different between families with R-12 seedlings generally greater than MO-7 seedlings. The R-12 seedlings had a 7.5 mmol m(-2) increase in ozone uptake compared to MO-7, and at the same cumulative O(3) exposure R-12 exhibited 40.9% stippled leaf area, whereas MO-7 had 9.2% stippled leaf area. Significant differences were observed in stem volume growth and total final biomass between the open-top chambers and open plots. Although R-12 had the most severe foliar ozone injury, this family had significantly greater stem volume growth and total final biomass than MO-7 and NS seedlings. Root:shoot ratio was not significantly different between MO-7 and R-12 seedlings. PMID:15093015

Kouterick, K B; Skelly, J M; Fredericksen, T S; Steiner, K C; Kolb, T E; Ferdinand, J A

2000-01-01

200

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

OpenAIRE

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

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

2014-01-01

201

Growth of North-east Arctic cod (Gadus morhua L.) in relation to ambient temperature  

OpenAIRE

Temperature related changes in horizontal distribution of North-east Arctic cod are described and the influence of temperature on the growth is interpreted. By using data from acoustic and bottom trawl surveys in the Barents Sea conducted in February1988–1995, mean length at age is related to the winter temperature. Mean lengths at age increased with increasing temperature for cod of age 2–6. Mean individual growth was highest for year classes experiencing high temperatures. Due to the se...

Michalsen, Kathrine; Ottersen, Geir; Nakken, Odd

1998-01-01

202

Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress  

Energy Technology Data Exchange (ETDEWEB)

Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

Lee, E.H. (Climate Stress Laboratory, USDA, ARS, Beltsville, MD (United States))

1991-01-01

203

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

Energy Technology Data Exchange (ETDEWEB)

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

Sanz, J., E-mail: j.sanz@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Bermejo, V., E-mail: victoria.bermejo@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Muntifering, R., E-mail: muntirb@auburn.ed [Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Gonzalez-Fernandez, I., E-mail: ignacio.gonzalez@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Gimeno, B.S., E-mail: benjamin.gimeno@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Elvira, S., E-mail: susana.elvira@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Alonso, R., E-mail: rocio.alonso@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain)

2011-02-15

204

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

Energy Technology Data Exchange (ETDEWEB)

The presence of UV-absorptive substances in the epidermal cells of leaves is thought to protect mesophyll tissues from the harmful effects of UV-B radiation. We examined the influence of short-term UV-B exposures on UV-absorptive (330 nm) sinapates and flavonols, and on shoot growth of the Arabidopsis wild type ecotype Landsberg erecta and two mutants, tt4, deficient in chalcone synthase, and tt5, deficient inchalcone/flavonone isomerase. Sequential ozone exposures were used to determine the effects of oxidative stress. The levels of sinapates and flavonols on a leaf fresh weight basis increased substantially in the wild type and sinapates increased in the tt4 mutant, in vegetative, vegetative/reproductive transitional and reproductive stage plants in response to short-term (ei h) UV-B radiation. When UV-B was discontinued the levels generally decreased to pre-exposure levels after 48 h in vegetative/reproductive but not in reproductive plants. Exposure to ozone before or after UV-B treatment did not consistently affect the levels of the UV-absorptive compounds. Dry matter accumulation was less affected by UV-B at the vegetative and reproductive stages than at the vegetative/reproductive stage. At the vegatative/reproductive stage, shoot growth of all 3 genotypes was retarded by UV-B. Growth was not retarded by short-term ozone exposure alone but when exposure to ozone followed UV-B exposure, growth was reduced in all genotypes. Leaf cupping appeared on tt5 plants exposed to UV-B. (au) (25 refs.)

Ormrod, D.P. [Univ. of Guelph, Dept. of HorticulturalScience, Guelph, On (Canada); Landry, L.G.; Conklin, P.L.; Thomson, B. [Cornell Univ., Institute for Plant Research, Ithaca, NY (United States)

1995-05-01

205

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

Science.gov (United States)

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

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

2014-07-01

206

Ozone Pollution  

Medline Plus

Full Text Available ... 22 had worse ozone problems. Weather played a factor. The warmer summers in 2010 and 2012 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 ...

207

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)

208

Five years of growth of soybean at elevated CO2 and ozone, an overview  

Science.gov (United States)

SoyFACE is the first FACE experiment to focus on a seed legume and on corn and the first to explore the interactions of both e[CO2] and e[O3] on the growth and development of an arable crop. The intent of the SoyFACE experiment is to orchestrate a coordinated and comprehensive investigation of the i...

209

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

Science.gov (United States)

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

210

Effects of low levels of ozone on growth of crimson clover and annual ryegrass  

Energy Technology Data Exchange (ETDEWEB)

Studies have been conducted on short term exposure of plants to broad ranges of O/sub 3/ concentration. Our purpose was to investigate long term exposure of plants to O/sub 3/ levels that were below those normally causing visible injury. Annual ryegrass (Lolium multiflorum Lam.) and crimson clover (Trifolium incarnatum L.) were grown for 6 weeks in chambers within a greenhouse and fumigated for 8 hours/day with 0.03 and 0.09 ppM O/sub 3/ in air. Treated plants showed less growth and yield than the controls despite the absence of visible injury. Both total dry weight and leaf area of treated plants were as much as 22% lower than the controls, but percent dry weight was significantly higher. Root growth was impaired the most, followed by stems and leaves, respectively, as evidenced by a lower root/shoot ratio and a slightly higher leaf weight ratio with O/sub 3/ treatment. Both species showed significantly lower specific leaf areas and leaf area ratios in O/sub 3/ compared to the control, but higher net assimilation rates led to relative growth rates which were unaffected. It was concluded that although the relative size of the leaf system was very sensitive to prolonged exposure to low O/sub 3/, compensation in growth parameters occurred to counteract the stress response.

Bennett, J.P. (Univ. of California, Davis); Runeckles, V.C.

1977-01-01

211

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

Directory of Open Access Journals (Sweden)

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

A. Laaksonen

2004-11-01

212

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

213

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

International Nuclear Information System (INIS)

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

214

On the growth-speed of the ambient noise cross-correlation function and its application  

Science.gov (United States)

Retrieving the Empirical Green's function (EGF) between two receivers by cross-correlating continuous records is now a well-recognized technique and the derived EGFs have been applied to various fields of seismology. In the common operation of noise cross-correlation, it is known that the signal-to-noise ratio (SNR) of cross-correlation functions (CCF) is generally increasing with the total correlation time. However, little attention has been given to a more quantitative description on how the noise-derived CCFs are developing with time. In this study, we analyze the CCF growth-speed quantitatively, and discuss its potential applications. In theory, the noise-derived CCF can be approximately composed of two parts, the time-independent term, which is related to the Green's function, and the time-dependent term, which is the product of unrelated noise sources, and its contribution in the CCF is decreasing with the total correlation time. Defining the final CCF, the one derived from all the available data, as the reference CCF, we may quantify the strength of unrelated noise sources using the rms of the waveform residual between a target CCF and the reference one. Since the rms is dropping with the growing correlation time of the target CCF, we may relate the rms to the CCF growth-speed when it is scaled by a properly defined time-dependent term. We evaluate the growth-speed for realistic CCF data set derived from the vertical component continuous seismic data recorded at 45 and 17 broadband stations in Taiwan and Korea, respectively. To remove the effects of temporal variations of the noises strength, the growing target CCFs are taken from a randomly daily CCF stack. Assuming the CCF with infinite correlation time is "noise-free", we may evaluate the "noises" strength in the CCFs at any given correlation time with the growth-speed. Instead of using an empirically defined SNR, the estimated "noise" strength provides a quantitative measure for the EGF quality. Such analysis could be used in any given time window in the CCF trace as well. In Taiwan, we have noted that the noise excitations in the frequency band of short period secondary microseism (3-7 seconds) is highly correlated with the water depth of the surrounding ocean, and its signature is clearly shown in the resulting CCFs. Interestingly, such correlations do not exist in the CCF growth-speed, which remains nearly constant through the evaluation of any station pairs, implying that the spatial distribution of the unrelated noises is relatively homogenous, unlike the apparent bathymetry-dependent "signal" sources. On the contrary, in Korea the CCF strength of 3-7 seconds is proportional to the growth-speed. Thus, the growth-speed does reveal additional information about the noise source which is inaccessible through the analysis of the common 'signal' of CCFs.

Chen, Y.; Gung, Y.; Chiao, L.

2013-12-01

215

MOVPE growth of improved nonequilibium MCT device structures for near-ambient-temperature heterodyne detectors  

Science.gov (United States)

Cadmium mercury telluride (Hg1-xCdxTe or MCT) non- equilibrium detector structures which allow room temperature operation have been grown by metal-organic vapor phase epitaxy (MOVPE). These devices suppress the auger generation by reducing the intrinsic electron and hole concentrations in the active region of the device. The MCT characteristics in this region should then be determined by the extrinsic doping concentration. In order to minimize the remaining generation processes within this so called (pi) -region, it is best formed from low acceptor doped (low X1015 cm-3) MCT, with as low a trap density as possible. The p+(pi) n+ device structure which is required to achieve the non-equilibrium phenomena requires stringent control on acceptor and donor doping, as well as composition. Acceptor doping studies with trisdimethylamino arsine (DMAAs) have been performed using GaAs and CdZnTe substrates. Minority carrier lifetime results have been obtained which are near rotatively limited and comparable to As-doped, Hg-rich liquid phase epitaxy (LPE) grown layers on CdZnTe substrates. Ambient temperature, auger-suppressed devices have levels of 1/f noise which currently limit their use in imaging applications. However, they are of great interest in other applications such as approximately equals 10 micrometer negative luminescence emitter devices and heterodyne detection of 10.6 micrometer infrared (IR) radiation from carbon-dioxide lasers. Reduction in the series resistances has been achieved by utilizing a device design with a n+ MCT common which should improve the frequency response of these devices. Another design modification, predicted to reduce the leakage current, has been the introduction of low doped, wide band gap regions either side of the (pi) -region. In practice these structures have produced over an order of magnitude improvement in the leakage current characteristics.

Maxey, C. D.; Jones, C. L.; Metcalfe, N. E.; Catchpole, R. A.; Gordon, Neil J.; White, A. M.; Elliot, C. T.

1997-10-01

216

A new predictive dynamic model describing the effect of the ambient temperature and the convective heat transfer coefficient on bacterial growth  

OpenAIRE

In this study, predictive microbiology and food engineering were combined in order to develop a new analytical model predicting the bacterial growth under dynamic temperature conditions. The proposed model associates a simplified primary bacterial growth model without lag, the secondary Ratkowsky "square root" model and a simplified two-parameter heat transfer model regarding an infinite slab. The model takes into consideration the product thickness, its thermal properties, the ambient air te...

Ben Yaghlene, Hana; Legue?rinel, Ivan; Hamdi, Moktar; Mafart, Pierre

2009-01-01

217

Antarctic Ozone  

Science.gov (United States)

This site provides near real time and historical data related to the extent of the ozone depletion in Antarctica. These graphs and plots can be used by students to determine differences in different seasons and allow substantial practice in reading graphs. The Ozone Hole Area graph provides a look at the extent of the Ozone hole in sq.km. over the past two years by month. The near real time data at this site includes ozone soundings from Neumayer Station; ozone soundings from South Pole Station; TIROS Operational Vertical Sounder (TOVS) (Satellite Picture); mean stratospheric temperatures; and ozone related links from the Norwegian Institute for Air Research (NILU) 2003. Historical data includes ozone soundings from Neumayer Station; ozone soundings of Georg Forster Station; timeseries of ozone partial pressure since 1985; and TOVS archive.

218

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

Science.gov (United States)

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

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

2015-01-01

219

Ozone dose-response relationships for spring oilseed rape and broccoli  

Science.gov (United States)

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

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

2011-03-01

220

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

Science.gov (United States)

A two-year experiment exposing Acer truncatum Bunge seedlings to elevated ozone (O3) concentrations above ambient air (AO) and drought stress (DS) was carried out using open-top chambers (OTCs) in a suburb of Beijing in north China in 2012-2013. The results suggested that AO and DS had both significantly reduced leaf mass area (LMA), stomatal conductance (Gs), light saturated photosynthetic rate (Asat) as well as above and below ground biomass at the end of the experiment. It appeared that while drought stress mitigated the expression of foliar injury, LMA, leaf photosynthetic pigments, height growth and basal diameter, due to limited carbon fixation, the O3 - induced reductions in Asat, Gs and total biomass were enhanced 23.7%. 15.5% and 8.1% respectively. These data suggest that when the whole plant was considered that drought under the conditions of this experiment did not protect the Shantung maple seedlings from the effects of O3. PMID:25765971

Li, Li; Manning, William J; Tong, Lei; Wang, Xiaoke

2015-06-01

221

Ozone Pollution  

Medline Plus

Full Text Available ... Card Widget Or Enter Your Zip Code: Ozone Pollution More than 4 in 10 people in the ... Communities will need more help to reduce ozone pollution in the warmer temperatures expected from the changing ...

222

Ozone Pollution  

Medline Plus

Full Text Available ... polluted by ozone, 22 had worse ozone problems. Weather played a factor. The warmer summers in 2010 ... pollution in the warmer temperatures expected from the changing climate. Los Angeles remained the city with the ...

223

Ozone Pollution  

Medline Plus

Full Text Available ... What Needs to Be Done Methodology and Acknowledgements Report Card Widget Or Enter Your Zip Code: Ozone ... slightly more unhealthy days than in the 2013 report. Twenty-two of the 25 most ozone-polluted ...

224

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

225

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

Science.gov (United States)

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

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

2010-05-01

226

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

International Nuclear Information System (INIS)

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

227

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

Energy Technology Data Exchange (ETDEWEB)

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

Kannan Selvaraj, Sathees [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Feinerman, Alan [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Takoudis, Christos G., E-mail: takoudis@uic.edu [Departments of Bioengineering and Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)

2014-01-15

228

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

229

Atmospheric ozone  

Science.gov (United States)

The book contains papers given during the All-Union Atmospheric Ozone Conference (Suzdal', October 1988). Papers are presented on the instruments and methodology for measuring atmospheric ozone; results of measurements of ozone, other atmospheric gases, and aerosol; measurements of ozone and of trace gases in the Antarctic; the chemistry and the radiation regime in the ozonosphere; and modeling the ozonosphere. Particular attention is given to reactions between ozone and heterogeneous components of the atmosphere and to changes in tropospheric ozone. It is shown that periods of seismic activity (in particular, earthquakes with values of M not less than 3.5) coincide with short-term (1-2-days long) increases in the atmospheric ozone content.

Kokin, G. A.

230

Atmospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

The book contains papers given during the All-Union Atmospheric Ozone Conference (Suzdal', October 1988). Papers are presented on the instruments and methodology for measuring atmospheric ozone; results of measurements of ozone, other atmospheric gases, and aerosol; measurements of ozone and of trace gases in the Antarctic; the chemistry and the radiation regime in the ozonosphere; and modeling the ozonosphere. Particular attention is given to reactions between ozone and heterogeneous components of the atmosphere and to changes in tropospheric ozone. It is shown that periods of seismic activity (in particular, earthquakes with values of M not less than 3.5) coincide with short-term (1-2-days long) increases in the atmospheric ozone content.

Kokin, G.A.

1990-01-01

231

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

232

Modeling the effect of temperature on ozone-related mortality  

OpenAIRE

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

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

2014-01-01

233

Variation in the relationship between ozone exposure and crop yield as derived from simple models of crop growth and ozone impact  

Science.gov (United States)

Causes of variation in O 3 dose-crop yield loss relationship ( D-R) were studied with the models of crop growth and O 3 effects. In the growth model, biomass accumulation was assumed to be proportional to solar radiation intercepted by the plant leaves. The O 3 impact was modeled as a linear function of the O 3 concentration less the background O 3. The models were combined to give analytical expressions of D-R between mean O 3 concentration ( overlineQ) and relative yield loss. The effects of O 3 on canopy photosynthesis and leaf abscission in reproductive growth were addressed. The O 3 impact on photosynthesis was modeled as a reduced canopy light-use efficiency (LUE). The resultant yield loss was proportional to overlineQ with the modification ( M) due to the fluctuations in O 3 and a weighting factor ( w), and to the correlation between them. The weighting factor is defined as daily biomass accumulation in the background O 3. If the sensitivity of canopy LUE is much higher during reproductive growth, the D-R was further modified by the ratio of weighted sum of O 3 during reproductive growth to that through a whole season. The D-R for the O 3 effect on leaf abscission was a hyperbolic function of overlineQ with modifications by M. The above analysis thus identified fluctuations in O 3 and the weighting factor as possible causes of the variation in the D-R.

Kobayashi, Kazuhiko

234

Ozone, antioxidant spray and meloidogyne hapla effects on tobacco  

Science.gov (United States)

The relationship between ozone and the northern root-knot nematode on tobacco was investigated. Seedlings of tobacco ( Nicotiana tabacum L.) cv. Virginia 115 were inoculated and not inoculated with root-knot ( Meloidogyne hapla (Chitwood) prior to transplanting to a field plot. One-half the plants were sprayed at weekly intervals with an antioxidant, EDU at the rate of 1 kg ha -1 to protect against oxidant injury. O 3 concentrations in excess of 80 ppb were recorded 14 times during the summer of 1982. Ambient ozone inhibited growth and yield of tobacco inoculated and not inoculated with M. hapla. Tobacco inoculated with nematode alone developed significantly more ozone injury than other treatments indicating that tobacco infected with M. hapla is more susceptible to ambient O 3. Significantly 20% more galls developed on plants with nematode inoculation compared to plants with nematode inoculation + EDU indicating that EDU indirectly reduced gall development in tobacco. Plants protected with EDU also showed an increase in dry weight of shoot, root and biomass.

Bisessar, S.; Palmer, K. T.

235

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

Science.gov (United States)

An understanding of the genetic determinants of keystone symbiotic relationships is essential to elucidating adaptive mechanisms influencing higher-order processes, including shifts in community composition following environmental perturbations. The Aspen FACE project offers a unique opportunity to address adaptive processes with an imposed three way interaction experiment composed of the atmospheric pollutant ozone (eO3), elevated CO2 (eCO2) fumigations, five Populus tremuloides (aspen) genotypes, and both arbuscular mycorrhizal and ectomycorrhizal fungal interactions. The 10 year time span of this experiment has allowed for a realistic and mechanistic understanding of above ground responses of the aspen genotypes to eCO2, eO3 and the interaction effects of eCO2 and eO3. Even so, treatment influences to the below ground, including carbon allocation to roots and associated mycorrhizal symbionts, and rhizosphere dynamics are just beginning to be understood. We hypothesized that mycorrhizal fungal responses to eCO2, eO3, and the interaction effects of eCO2+eO3 are conditioned by the degree of response of their aspen hosts. We intend to describe the molecular mechanisms of an important critical interaction between host and fungus using microarray analysis of expression profiles, as well as metabolic profiling of aspen roots and their associated mycorrhizal partner, the arbuscular mycorrhizal fungus (AMF) Glomus intraradices, under eCO2, eO3 and eCO2+eO3. We present evidence that host-derived factors, expressed in response to eCO2+eO3, trigger responses in Glomus leading to the partitioning or metabolic shift in lipid biosynthesis that is associated with reduced extraradical hyphae growth and altered lipid metabolism. We then scale these lower-level responses to give better insight to fungal intraradical and extraradical allocation of biomass and fungal and root lipid and carbohydrate content in association with aspen genotype responses to the imposed treatments. By evaluating microarray data of more than 2300 genes that are regulated (out of 25,000) in aspen mycorrhizal roots, the eCO2 responsive and eO3 tolerant aspen ecotype 271 demonstrated upregulation for antioxidant genes under eCO2+eO3 conditions. We found decreased expression of both neutral and acid invertase genes indicating that the availability of carbohydrate to the fungus is reduced. We also found an increase in plant amino acid transporters under eO3 and eCO2+eO3 that partitions more nitrogen to the plant from mycorrhizal roots and triggers the fungus into an N-starvation and lipid storage mode. This observation is supported by down-regulation of genes involved in nitrogen utilization in Glomus and the enrichment of hyphal 15N content, as well as an increase in the AMF marker storage lipid (neutral fatty acid 16:1w5c)in the root. The up-regulation of pathways involved in the formation of triglycerides that can be taken up by the fungus may be a critical step for changes in Glomus lipid metabolism. Also, in support of the above findings, is the rather high expression of genes involved in iron sequestration by aspen clone 271 when exposed to both eO3 and eCO2+eO3 fumigation. Iron is needed for both fatty acid (FA) desaturases and fatty acid synthase. Under eCO2+eO3, we found down-regulation of FA desaturases in Glomus, suggesting reduced levels of iron could be a potential signal for the fungus to go into storage mode and reduced growth of extraradical hyphae into the soil.

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

2008-12-01

236

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

237

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.

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

238

Use of a single-tree simulation model to predict effects of ozone and drought on growth of a white fir tree.  

Science.gov (United States)

A physiologically based, single-tree simulation model, TREGRO, was parameterized with existing phenological, allometric, and growth data and used to predict effects of ozone and drought on growth of a 53-year-old white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) tree following a 3-year model simulation. Multiple experimental simulations were conducted to assess the individual and interactive effects of ozone (O(3)) exposure and drought on growth of white fir. The effects of O(3) were imposed as reductions in carbon (C) assimilation of 0, 2.5, 5, 10, and 20%. Drought was imposed as 0, 10, 25, and 50% reductions in total annual precipitation. The results of the simulations were compared with the effects of O(3) on white fir seedlings grown in the presence and absence of ozone in open-top chambers and with a field survey of white fir trees subjected to a gradient of O(3). In the O(3) simulations, an O(3)-induced reduction in C assimilation of 2.5% reduced total tree biomass and branch total nonstructural carbohydrate (TNC) content by simulation experiments, such small reductions would probably not be detectable in the field. Results from both an open-top chamber experiment and a field survey indicated that reductions in C assimilation of white fir growing in elevated O(3) were much greater than 2.5%, but were not statistically different from control values. A simulated O(3) reduction in C assimilation of >/= 10% reduced total tree biomass by 7% and branch TNC by 55%. Results from the field survey indicated that branch elongation was reduced in response to increased O(3) concentration, corroborating the simulated response of reduced C allocation to the branches of white fir. Although simulated reductions in total annual precipitation of >/= 25% reduced final tree biomass, the simulated reductions also reduced O(3) uptake and therefore reduced the O(3) response of white fir. However, a combination of low amounts of O(3) (2.5% reduction in C assimilation) and drought (25% reduction in annual precipitation) synergistically reduced C gain of white fir more than either stress individually. Our simulations predict that moderate drought (no more than a 25% reduction in total annual precipitation) may not ameliorate the response of white fir to O(3) and that moderate amounts of atmospheric O(3) and drought could be more detrimental to white fir than either stress singly. PMID:12651472

Retzlaff, W. A.; Arthur, M. A.; Grulke, N. E.; Weinstein, D. A.; Gollands, B.

2000-02-01

239

Ozone and cardiovascular injury  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Air pollution is increasingly recognized as an important and modifiable determinant of cardiovascular diseases in urban communities. The potential detrimental effects are both acute and chronic having a strong impact on morbidity and mortality. The acute exposure to pollutants has been linked to adverse cardiovascular events such as myocardial infarction, heart failure and life-threatening arrhythmias. The long-terms effects are related to the lifetime risk of death from cardiac causes. The WHO estimates that air pollution is responsible for 3 million premature deaths each year. The evidence supporting these data is very strong nonetheless, epidemiologic and observational data have the main limitation of imprecise measurements. Moreover, the lack of clinical experimental models makes it difficult to demonstrate the individual risk. The other limitation is related to the lack of a clear mechanism explaining the effects of pollution on cardiovascular mortality. In the present review we will explore the epidemiological, clinical and experimental evidence of the effects of ozone on cardiovascular diseases. The pathophysiologic consequences of air pollutant exposures have been extensively investigated in pulmonary systems, and it is clear that some of the major components of air pollution (e.g. ozone and particulate matter can initiate and exacerbate lung disease in humans 1. It is possible that pulmonary oxidant stress mediated by particulate matter and/or ozone (O3 exposure can result in downstream perturbations in the cardiovasculature, as the pulmonary and cardiovascular systems are intricately associated, and it is well documented that specific environmental toxins (such as tobacco smoke 2 introduced through the lungs can initiate and/or accelerate cardiovascular disease development. Indeed, several epidemiologic studies have proved that there is an association between PM and O3 and the increased incidence of cardiovascular morbidity and mortality 3. Most of the evidence comes from studies of ambient particles concentrations. However, in Europe and elsewhere, the air pollution profile has gradually changed toward a more pronounced photochemical component. Ozone is one of the most toxic components of the photochemical air pollution mixture. Indeed, the biological basis for these observations has not been elucidated. In the present review, the role of ozone as chemical molecule will be firstly considered. Secondly, pathogenetic mechanisms connecting the atmospheric ozone level and cardiovascular pathology will be examined. Thirdly, the literature relating hospitalization frequency, morbidity and mortality due to cardiovascular causes and ozone concentration will be studied. The correlation between ozone level and occurrence of acute myocardial infarction will be eventually discussed.

Rainaldi Giuseppe

2009-06-01

240

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

International Nuclear Information System (INIS)

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 flavonoiimportant 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)

241

Ozone and increased nitrogen supply effects on the yield and nutritive quality of Trifolium subterraneum  

Science.gov (United States)

The influence of ambient ozone (O 3) concentrations and nitrogen (N) fertilization, singly and in combination, on the growth and nutritive quality of Trifolium subterraneum was assessed. This is an important O 3-sensitive species of great pastoral value in Mediterranean areas. Plant material was enclosed in open-top chambers (OTCs). Three O 3 levels were established: Filtered air with O 3 concentrations below 15 ppb (CFA), non-filtered air with O 3 concentrations in the range of ambient levels (NFA), and non-filtered air supplemented with 40 ppb O 3 over ambient levels (NFA+). Similarly, three N levels were defined: 5, 15 and 30 kg ha -1. The increase in O 3 exposure induced a reduction of the clover aerial green biomass and an increase of senescent biomass. Ozone effects were more adverse in the root system, inducing an impairment of the aerial/subterranean biomass ratio. Compared with the CFA treatment, nutritive quality of aerial biomass was 10 and 20% lower for NFA and NFA+ treatments, respectively, due to increased concentrations of acid detergent fiber, neutral detergent fiber and lignin. The latter effect appears to be related to senescence acceleration. The increment in N supplementation enhanced the increase of ADF concentrations in those plants simultaneously exposed to ambient and above-ambient O 3 concentrations, and reduced the incremental rate of foliar senescence induced by the pollutant.

Sanz, J.; Muntifering, R. B.; Bermejo, V.; Gimeno, B. S.; Elvira, S.

242

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

243

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

OpenAIRE

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

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

2010-01-01

244

Ozone fumigation results in accelerated growth and persistent changes in the antioxidant system of Brassica oleracea L. var. capitata f. alba.  

Science.gov (United States)

The growth response and antioxidant capacity of Brassica oleracea var. capitata f. alba plants treated with 70ppb of ozone was examined. Four week old cabbage seedlings were fumigated with O3 for 3 days before being transplanted into the growing field. The effect of O3 treatment was determined directly after fumigation and over the course of field cultivation. Plants subjected to O3 treatment had an increased diameter of rosettes and number of leaves after 3 and 7 weeks in agriculture, respectively. In addition, the vast majority of fumigated plants reached marketable quality faster than control plants, indicating a positive role of episodes of increased O3 concentrations during vegetation on growth and yielding. Our analysis revealed that by fumigating juvenile white cabbage plants with moderate doses of O3 the activity of catalases (CAT) and peroxidases was elevated. The activity of the examined enzymes was not affected directly after fumigation, but it increased after several weeks in the experimental field. Increased CAT activity was accompanied by changes in 2 out of the 3 CAT genes CAT1 and CAT2, where CAT2 seemed to be responsible for the induced CAT activity. The biosynthesis of low-molecular stress protectants - tocopherols and the glucosinolate (GLS) sinigrin was transiently affected by ozone. ?-Tocopherol (?-toc) content significantly increased directly after fumigation, but after 3 weeks of vegetation in the field its concentration reached values similar to control. The biosynthesis of ?-tocopherol (?-toc) and sinigrin seemed to be upregulated in fumigated plants. However, the response was delayed; no differences were registered directly after treatment, but 3 weeks after transplanting the concentration of sinigrin and ?-toc was elevated. PMID:23773692

Rozp?dek, Piotr; ?lesak, Ireneusz; Cebula, Stanis?aw; Waligórski, Piotr; Dziurka, Micha?; Skoczowski, Andrzej; Miszalski, Zbigniew

2013-09-15

245

Ozone Pollution  

Science.gov (United States)

In class, students are introduced to atmospheric composition and how this can be altered by human activities. As an example, ozone is introduced as an air pollutant, mostly due to human activities. Computer models are used to illustrate the formation of ozone and demonstrate the factors that affect the concentration of ozone in the troposphere (using the SmogCity2 simulation game). The health hazards of ozone pollution are deliberated on, and the concept of 'ozone alert day' introduced. As class example, the instructor obtains data from http://airnow.gov/ to investigate the relationship between ozone pollution in Kansas City and the season. The result of the investigation is reported in a sample mini-journal paper. The students' assignment is to select a city of choice in the United States, and use data to investigate the relationship between ozone pollution and any of the following: season, human population industrialization, city location, or asthma. This activity gives students practice in using data to investigate an air pollution problem and communicate their result to others in a standard format. Each student will report the result of their investigation in a mini-journal paper, with a relevant title, and the following sub-sections: an abstract, introduction, methods, results, discussion and references. Guided by a grading rubric, this activity helps student to learn how to a write technical paper.

Omowumi Alabi

246

Ozone decomposition  

Directory of Open Access Journals (Sweden)

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

Batakliev Todor

2014-06-01

247

Ozone modeling  

International Nuclear Information System (INIS)

Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO2), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NOx concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NOx coordinates of the point, known as the NMOC/NOx ratio. Results obtained by the described model are presented

248

Effect of Ambient Temperature and Light Intensity on Growth Performance and Carcass Characteristics of Heavy Broiler Chickens at 56 Days of Age  

OpenAIRE

The effects of ambient temperature, light intensity and their interaction on growth performance and carcass characteristics of broilers were investigated in 2 trials. The experiment was consisted of a factorial arrangement of treatments in a randomized complete block design. The 9 treatments consisted of 3 levels (Low = 15.6, Moderate = 21.1, High = 26.7oC) of temperatures from d 21-56 d of age and 3 levels (0.5, 3.0, 20 lx) of light intensities from 8-56 d of age at 50% RH. Five hundred and ...

Collier, S. D.; Purswell, J. L.; Olanrewaju, H. A.; Branton, S. L.

2010-01-01

249

New ozone depleting chemical found  

Science.gov (United States)

Scientists in Australia say they have discovered another chemical that is depleting the ozone in the upper atmosphere. They say it is not controlled by the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, and has an as-yet unknown source."The rapid growth of halon-1202 comes as a surprise to us," says Paul Frasier, an atmospheric scientist with Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO).

Showstack, Randy

250

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

251

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

252

Ozone Pollution  

Medline Plus

Full Text Available ... What You Can Do News from the American Lung Association New Ozone Standards Will Save Lives, Protect ... Releases News Stories Web Banners Contact Information American Lung Association 55 W. Wacker Drive, Suite 1150 Chicago, ...

253

Ozone Pollution  

Medline Plus

Full Text Available ... Cities » 25 Cleanest Cities for Ozone 1 Complete names for all these metropolitan areas can be found ... the FREE State of the Air® App Protect your health and download the American Lung Association’s free ...

254

The Ozone  

Science.gov (United States)

This site is a joint effort of NOAA Research and the College of Education at the University of South Alabama. The goal of the site is to provide middle school science students and teachers with research and investigation experiences using on-line resources. In this unit students investigate ozone as a gas and a major component of the Earth's atmosphere. Students use information to explain ozone depletion, the harmful effects of ozone at ground level, and look at the economics of passing ozone-related laws. Parts of the unit include gathering information from other websites, applying the data gathered, and performing enrichment exercises. This site contains a downloadable teachers guide, student guide, and all activity sheets to make the unit complete.

255

Ozone Pollution  

Science.gov (United States)

... Save Lives Protect Yourself from Lethal Wildfire Smoke Smart links footer - Homepage Key Findings Ozone Pollution Year Round Particle Short Term Particle Cleanest Cities People at Risk Protect Yourself Methodology City Rankings ...

256

Ozone Pollution  

Medline Plus

Full Text Available ... Save Lives Protect Yourself from Lethal Wildfire Smoke Smart links footer - Homepage Key Findings Ozone Pollution Year Round Particle Short Term Particle Cleanest Cities People at Risk Protect Yourself Methodology City Rankings ...

257

Ozone Pollution  

Medline Plus

Full Text Available ... FACT: The American Lung Association fights for reduced power plant emissions - especially carbon - and stronger safeguards. Help ... Obama Administration’s Ozone Pollution Standards New Study: Reducing Power Plant Carbon Emissions Would Reduce Other Pollutants and ...

258

Ozone Pollution  

Medline Plus

Full Text Available ... The American Lung Association fights for reduced power plant emissions - especially carbon - and stronger safeguards. Help us ... Administration’s Ozone Pollution Standards New Study: Reducing Power Plant Carbon Emissions Would Reduce Other Pollutants and Save ...

259

Ozone Pollution  

Medline Plus

Full Text Available ... State of the Air® app. Learn More » Trusted Links AirNow National Association of Clean Air Agencies U. S. ... Lives Protect Yourself from Lethal Wildfire Smoke Smart links footer - Homepage Key Findings Ozone Pollution Year Round ...

260

Ozone Pollution  

Medline Plus

Full Text Available ... 10 people in the United States (44.8%) live in areas with unhealthful levels of ozone. What ... Health Risks . More than 140.5 million people live in the 296 counties that received an F ...

261

Ozone Pollution  

Medline Plus

Full Text Available ... live in the 296 counties that received an F for ozone levels. These people live where the ... 1150 Chicago, IL 60601 T: 1-800-LUNGUSA | F: 202-452-1805 Connect with Us Follow us ...

262

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

263

Ozone field studies adjacent to a hvdc transmission test line  

Energy Technology Data Exchange (ETDEWEB)

Field studies of atmospheric ozone concentrations adjacent to high voltage direct current (hvdc) transmission test lines were conducted at the Bonneville Power Administration's (BPA) hvdc Test Facility at The Dalles, Oregon. The transmission lines were operating at voltages from +- 400 to +- 600 kV during the field studies. The downwind ozone plumes were studied using a roving vertical profiling system. Ambient meteorological and test line parameters were also recorded to allow comparison of predicted and observed ozone plumes. For fair weather conditions no ozone plumes were evident. The absence of identifiable changes in ozone concentrations by the energized lines demonstrates the trivial nature of the ozone concentrations from the energized lines for fair weather conditions. Since corona loss from power lines is largest during precipitation, the ozone production is also largest. At the same time, the natural background atmospheric ozone concentrations are depressed by the scavenging effect of the precipitation. Therefore ozone production rates can best be measured during precipitation periods. With the exception of precipitation cases, the vertical profiles of ozone concentration demonstrated no discernible evidence of ozone plumes from the energized conductors. Ozone plumes, if any, were masked in the natural background ozone variability.

Droppo, J.G.; Abbey, O.B.; Glover, D.W.

1979-03-01

264

Characterisation of the ozone sensitivity of Central European plant species: relation to taxonomy, ecology, growth rates and leaf density; Charakterisierung der Ozonsensitivitaet mitteleuropaeischer Pflanzenarten: Beziehung zu Taxonomie, Oekologie, Wachstumsraten und Blattdichte  

Energy Technology Data Exchange (ETDEWEB)

Fumigation experiments with wild plant species performed in recent years are not necessarily representative for the Central European flora, especially when it comes down to the use of species from red data books in these studies. Moreover, ozone experiments are not representative with respect to plant life forms, taxonomy and ecology. However, first tendencies can be derived: Legumes and Compositae are families comprising many sensitive species with regard to acute injury and growth reductions due to ozone. In contrast to this, the family of Sweet Grasses contains some species with growth stimulations due to ozone. Fastgrowing ruderal strategists and competitive species tend to respond more pronounced than slow-growing species. On the average, plant species with acute injury have thinner leaves than those showing no symptoms. (orig.) [German] Die bislang in Begasungsversuchen untersuchten Wildpflanzenarten repraesentieren nur einen kleinen Teil der mitteleuropaeischen Flora, besonders die Arten der Roten Liste sind noch unterrepraesentiert. Auch hinsichtlich Lebensformen, Taxonomie und Oekologie ist die Ozonwirkungsforschung an Wildpflanzen nur bedingt repraesentativ. Aus den bislang durchgefuehrten Experimenten lassen sich jedoch erste Tendenzen erkennen: Die Familien der Schmetterlings- und Korbblueter enthalten viele ozonsensitive Taxa, was akute Schaeden und Wuchsminderungen anbelangt. In der Familie der Suessgraeser gibt es andererseits Arten, die auf Ozon mit einer Wachstumsstimulierung reagieren. Schnellwuechsige Ruderalstrategen und konkurrenzstarke Arten erweisen sich insgesamt ozonsensitiver als die langsamwuechsigen Arten. Pflanzenarten mit akuter Blattschaedigung haben im Mittel duennere Blaetter als Arten ohne sichtbare Schaeden. (orig.)

Franzaring, J.

2000-07-01

265

Ozone Pollution and Farm Profits in England and Wales  

OpenAIRE

Abstract Tropospheric ozone is an air pollutant known to adversely affect crop yields across Europe. Experimental work is underway to quantify yield effects at ambient ozone levels for a number of crops. In this paper, we undertake direct, farm-level evaluation of the impact of ozone by estimating a multi-output profit function using a panel dataset of cereal farms in England and Wales. A system of equations, comprising the profit function, input and output share equations is esti...

Neeliah, Harris; Shankar, Bhavani

2009-01-01

266

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

267

Test/QA Plan for Verification of Ozone Indicator Cards  

Science.gov (United States)

This verification test will address ozone indicator cards (OICs) that provide short-term semi-quantitative measures of ozone concentration in ambient air. Testing will be conducted under the auspices of the U.S. Environmental Protection Agency (EPA) through the Environmental Tec...

268

Role of Ozone in Particle Formation and Growth From the Nitrate Radical-Initiated Oxidation of ?-Pinene  

Science.gov (United States)

The three major atmospheric oxidants involved in SOA formation from biogenic volatile organic compounds are O3, OH and nitrate radical (NO3). While O3 and OH-initiated oxidation occur during the day, NO3 radical-initiated oxidation is recognized to be a major contributor to the night-time chemistry of volatile organic compounds in the troposphere. Specifically, the reaction of biogenic hydrocarbons with NO3 is relatively fast (for example, lifetime of ?-pinene is only ~11 min at 2.5 x 10^8 NO3 molecules cm-3), so this reaction is expected to be a major sink of the organics at night, and also to contribute to the removal of NOx from the atmosphere. Previous studies by other groups have shown that SOA yield from the NO3 reaction is relatively small due to the high volatility of the reaction products, in contrast to the O3 reaction which is an important SOA source in the atmosphere. We report the results of experiments designed to probe the influence of ozone on particle formation and composition in the NO3 oxidation of ?-pinene. The experiments were performed in a large diameter flow tube using the reaction of NO2 with O3 as the source of NO3 radicals. Particle size distributions were measured using a scanning moblity particle sizer (SMPS) and an aerodynamic particle sizer (APS). Real-time aerosol mass spectrometers (SPLAT-II and AMS) as well as integrated collection of particles on ZnSe impaction disks and quartz fiber filters were used to characterize the chemical composition of the particles. Organic nitrates were major components of the particles at high ratios of NO2/O3 but decreased as this ratio decreased. The particle size distribution also shifted. In addition, the formation of other species with low vapor pressures such as carboxylic acids was observed due to the increasing contribution from the O3-initiated oxidation of ?-pinene. The role of ozone as a source of nucleation in this system will be discussed.

Perraud, V. M.; Bruns, E. A.; Ezell, M. J.; Johnson, S. N.; Yu, Y.; Alexander, M. L.; Zelenyuk, A.; Imre, D. G.; Finlayson-Pitts, B. J.

2009-12-01

269

Atmospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

The major findings discussed in this paper are based upon the results of several major ground-based and aircraft field campaigns in the polar regions, a reanalysis of ground-based ozone data from the past thirty-one years, a reanalysis of satellite ozone and polar stratospheric cloud (PSC) data, laboratory studies of gas-phase and surface-induced chemical processes, and model simulations incorporating these new laboratory data and observations. Protection of the ozone layer would require: (1) a phase-out in the production and emission of long-lived halocarbons (CFCs and carbon tetrachloride) as soon as possible; (2) 100% compliance; (3) reduction in the production and emission of methylchloroform; (4) elimination of the emissions of all chlorine and bromine containing chemicals (including the HCFCs) sometime in the middle of the next century; and (5) stabilization of atmospheric bromine at today's levels or below.

Watson, R.T. (NASA, Washington, DC (USA))

1990-05-01

270

Ozonation of sediments from an urban lake: an exploratory investigation  

Scientific Electronic Library Online (English)

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

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

2011-09-01

271

Growth of ponderosa pine seedlings as affected by air pollution  

Science.gov (United States)

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

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

272

Ozone loss in soot aerosols  

Science.gov (United States)

The fractal-like structure of atmospheric soot (e.g., elemental carbon) provides a large surface area available for heterogeneous chemistry in the upper troposphere and lower stratosphere [Blake and Kato, 1995]. One potentially important reaction is ozone decomposition on soot. Although extensively studied in the laboratory, a wide range of reaction probabilities have been observed (?˜10-3 to ?˜10-7) which have been attributed to differences in reactivity between fresh (i.e., nonoxidized) versus aged (i.e., oxidized) soot [Schurath and Naumann, 1998]. The importance in understanding soot-ozone chemistry is particularly important in light of recent nighttime field measurements [Berkowitz et al., 2000] made over Portland, Oregon. The data revealed episodes of an anticorrelation between ozone mixing ratio and aerosol surface area density. During these episodes a single scattering albedo in the range 0.8-0.9 was measured, indicating an increased absorptive component of the aerosol, perhaps due to elemental carbon. In addition, an increase in the concentration of aerosols contained in the small size range of the fine mode (<0.1-0.15 ?m) was observed, suggestive of new aerosol formation. In this article we attempt to explain these field observations. One explanation of the field observations is ozone loss occurring on atmospheric soot aerosol. Here we present laboratory results obtained using a static aerosol reactor that indicate that direct ozone loss on soot aerosol is unlikely under ambient conditions in the troposphere. An alternative and more likely explanation of the field data is based on ozone-mediated organic aerosol production. This could occur by either nighttime nitrate radical oxidation or direct ozone oxidation of hydrocarbons as suggested previously [Starn et al., 1998; Griffin et al., 1999; Kamens et al., 1999; Yu et al., 1999; De Gouw and Lovejoy, 1998].

Disselkamp, R. S.; Carpenter, M. A.; Cowin, J. P.; Berkowitz, C. M.; Chapman, E. G.; Zaveri, R. A.; Laulainen, N. S.

2000-04-01

273

Genes of innate immunity and the biological response to inhaled ozone  

OpenAIRE

Ambient ozone has a significant impact on human health. We have made considerable progress in understanding the fundamental mechanisms that regulate the biological response to ozone. It is increasingly clear that genes of innate immunity play a central role in both infectious and non-infectious lung disease. The biological response to ambient ozone provides a clinically relevant environmental exposure that allows us to better understand the role of innate immunity in non-infectious airways di...

Li, Zhuowei; Tighe, Robert M.; Feng, Feifei; Ledford, Julie G.; Hollingsworth, John W.

2012-01-01

274

A gas-solid reaction growth of dense TiO2 nanowire arrays on Ti foils at ambient atmosphere.  

Science.gov (United States)

In this paper, a facile method is demonstrated to directly fabricate dense titania nanowire arrays on titanium foils under the atmosphere without extra moist conditions. The influences of temperature, time, different catalysts, and concentrations of the respective catalysts on the growth of titania nanowires are discussed in detail. The morphology, composition and crystal structure of the titania nanostructures are revealed by scanning electron microscopy (SEM), powder-X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques, by which a gas-solid reaction mechanism is suggested to explain the growth process of TiO2 nanowires on Ti substrate. PMID:22523981

Wei, Zhishun; Liu, Ying; Wang, Hui; Mei, Zongwei; Ye, Jinwen; Wen, Xiaogang; Gu, Lin; Xie, Yutao

2012-01-01

275

Ozone Pollution  

Medline Plus

Full Text Available ... What You Can Do News from the American Lung Association How Public Health Issues Affect Lung Health New Ozone Standards Will Save Lives, Protect ... Releases News Stories Web Banners Contact Information American Lung Association 55 W. Wacker Drive, Suite 1150 Chicago, ...

276

Ozone Pollution  

Medline Plus

Full Text Available ... polluted metropolitan areas—some substantially—in 2010-2012 compared to 2009-2011. Of the 25 metro areas ... high ozone days on average in 2010-2012 compared to 2009-2011. Fortunately, even these places have ...

277

TROP OZONE  

Science.gov (United States)

Activity Area (F01) The NRMRL tropospheric ozone research program is both coordinated with the research efforts of others and planned to achieve the most important unmet research needs that draw upon its unique expertise. For example, NRMRL emissions research in this area is co...

278

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,...

279

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

280

Surface ozone measurements using differential absorption lidar  

Science.gov (United States)

Human activities have been influencing the global atmosphere since the beginning of the industrial era, causing shifts from its natural state. The measurements have shown that tropospheric ozone is increasing gradually due to anthropogenic activities. Surface ozone is a secondary pollutant, its concentration in lower troposphere depends upon its precursors (CO, CH4, non methane hydrocarbons, NOx) as well as weather and transport phenomenon. The surface ozone exceeding the ambient air quality standard is health hazard to human being, animal and vegetation. The regular information of its concentrations on ground levels is needed for setting ambient air quality objectives and understanding photo chemical air pollution in urban areas. A Differential Absorption Lidar (DIAL) using a tunable CO2 laser has been designed and developed at National Physical Laboratory, New Delhi, to monitor water vapour, surface ozone, ammonia, ethylene etc. Some times ethylene and surface ozone was found to be more than 40 ppb and 140 ppb respectively which is a health hazard. Seasonal variation in ozone concentrations shows maximum in the months of summer and autumn and minimum in monsoon and winter months. In present communication salient features of experimental set up and results obtained will be presented in detail.

Jain, Sohan L.; Arya, B. C.; Ghude, Sachin D.; Arora, Arun K.; Sinha, Randhir K.

2005-01-01

281

Cyclic-load crack growth in ASME SA-105 grade II steel in high-pressure hydrogen at ambient temperature  

Science.gov (United States)

ASME SA-105 Grade II steel, which is used in high-pressure hydrogen compressor systems, is similar to steels used or considered for use in high-pressure hydrogen storage vessels and pipelines. This paper summarizes the results of a program conducted to provide cyclic-load crack growth rate (da/dN) data for a fracture mechanics analysis of a 15,000 psi hydrogen compressor facility which contains pulse quieter and after-cooler separator vessels constructed of the ASME SA-105 Grade II steel. Included in the program were tests performed to assist in establishing operating procedures that could minimize the effect of hydrogen on crack growth rates during operation.

Walter, R. J.; Chandler, W. T.

1976-01-01

282

Impacts of ambient salinity and copper on brown algae: 1. Interactive effects on photosynthesis, growth, and copper accumulation.  

Science.gov (United States)

The effect of copper enrichment and salinity on growth, photosynthesis and copper accumulation of two temperate brown seaweeds, Ascophyllum nodosum and Fucus vesiculosus, was investigated in laboratory experiments. A significant negative impact of reduced salinity on photosynthetic activity and growth was observed for both species. After 15 days at a salinity of 5, photosynthesis of A. nodosum was entirely inhibited and growth ceased at a salinity of 15. Increased copper concentration negatively affected photosynthetic activity of A. nodosum and F. vesiculosus resulting in chlorosis and reduced seaweed growth; 5 mg L?¹ copper caused an inhibition of the photosynthesis and the degradation of seaweed tips. Under reduced salinity, copper toxicity was enhanced and caused an earlier impact on the physiology of seaweed tips. After exposure to copper and different salinities for 15 days, copper contents of seaweeds were closely related to copper concentration in the water; seaweed copper contents reached their maximum after 1 day of exposure; contents only increased again when additional, free copper was added to the water. At high water copper concentrations or low salinity, or a combination of both, copper content of A. nodosum decreased. By contrast, copper content of F. vesiculosus increased, suggesting that different binding sites or uptake mechanisms exist in the two species. The results suggest that when using brown seaweeds in biomonitoring in situ, any change in the environment will directly and significantly affect algal physiology and thus their metal binding capacity; the assessment of the physiological status of the algae in combination with the analysis of thallus metal content will enhance the reliability of the biomonitoring process. PMID:21549661

Connan, Solène; Stengel, Dagmar B

2011-07-01

283

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

OpenAIRE

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 fo...

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

2013-01-01

284

Comparative study of ozonized olive oil and ozonized sunflower oil  

Scientific Electronic Library Online (English)

Full Text Available Neste estudo, óleos de oliva e girassol ozonizados foram comparados química e microbilogicamente. Estes óleos foram introduzidos em um reator com gás ozônio borbulhante, em banho-maria a temperatura ambiente, até solidificação. O teor de peróxido, de iodo e o grau de acidez foram determinados juntam [...] ente com a atividade antimicrobiana. Os efeitos da ozonização na composição dos ácidos graxos desses óleos foram analisados usando-se a técnica de Cromatografia Gás-Líquido. Um aumento nos valores de peroxidação e de acidez foi observado em ambos os óleos, mas foram maiores no óleo de girassol ozonizado. O teor de iodo obtido no azeite de oliva ozonizado foi zero, enquanto no óleo de girassol ozonizado foi de 8,8 g de iodo per 100 g. A atividade antimicrobiana foi similar para os dois óleos ozonizados, com exceção da Concentração Mínima Bactericida de Pseudomona Aruginosa. A composição dos ácidos graxos nos dois óleos ozonizados mostrou um decréscimo gradual de ácidos graxos insaturados (C18:1, C18:2), com o aumento gradual da ozonização. Abstract in english In this study the ozonized olive and sunflower oils are chemical and microbiologically compared. These oils were introduced into a reactor with bubbling ozone gas in a water bath at room temperature until they were solidified. The peroxide, acidity and iodine values along with antimicrobial activity [...] were determined. Ozonization effects on the fatty acid composition of these oils were analyzed using Gas-Liquid Chromatographic Technique. An increase in peroxidation and acidity values was observed in both oils but they were higher in ozonized sunflower oil. Iodine value was zero in ozonized olive oil whereas in ozonized sunflower was 8.8 g Iodine per 100 g. The antimicrobial activity was similar for both ozonized oils except for Minimum Bactericidal Concentrations of Pseudomona aeruginosa. Composition of fatty acids in both ozonized oils showed gradual decrease in unsaturated fatty acids (C18:1, C18:2) with gradual increase in ozone doses.

Maritza F., Díaz; Rebeca, Hernández; Goitybell, Martínez; Genny, Vidal; Magali, Gómez; Harold, Fernández; Rafael, Garcés.

2006-04-01

285

Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example  

International Nuclear Information System (INIS)

Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300 ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30 ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation. - An Italian population of the deciduous shrub Hibiscus syriacus, a common ornamental species in temperate zones, is recommended as ozone bioindicator

286

Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example  

Energy Technology Data Exchange (ETDEWEB)

Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300 ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30 ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation. - An Italian population of the deciduous shrub Hibiscus syriacus, a common ornamental species in temperate zones, is recommended as ozone bioindicator.

Paoletti, Elena [Institut Plant Protection (IPP), National Council Research (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy)], E-mail: e.paoletti@ipp.cnr.it; Ferrara, Anna Maria [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Calatayud, Vicent; Cervero, Julia [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Giannetti, Fabio [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Sanz, Maria Jose [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States)

2009-03-15

287

Ozone Pollution  

Medline Plus

Full Text Available ... U. S. Environmental Protection Agency sites: Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality ... Press Materials Press Releases News Stories Web Banners Contact Information American Lung Association 55 W. Wacker Drive, Suite ...

288

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...

289

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

Science.gov (United States)

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

290

Effects of ozone on crops in north-west Pakistan.  

Science.gov (United States)

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. PMID:23279903

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

2013-03-01

291

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

292

Effects of chronic ozone exposure on gene expression in Arabidopsis thaliana ecotypes and in Thellungiella halophila.  

Science.gov (United States)

Arabidopsis thaliana (At) ecotypes Columbia-0 (Col-0), Wassilewskija (WS), Cape Verde Islands (Cvi-0) and a relative, Thellungiella halophila (Th), were exposed to 20-25% over ambient ozone [O3] in a free air concentration enrichment (FACE) experiment (http://www.soyFACE. uiuc.edu), mirroring increases expected in the near future. Col-0 and WS accelerated development and developed lesions within 10 d under increased ozone, while Cvi-0 and Th grew slowly. RNAs were used in microarray hybridizations (Col-0-based 26 000 elements, 70-mer oligonucleotides). A two-step analysis of variance (ANOVA) model, including comparison with values obtained under [O3], was used for analyses. WS showed the greatest number of changes in gene expression in response to ozone. Th showed the least changes, suggesting that its expression state at [O3] was sufficient for resistance at increased ozone. Patterns observed in ambient air controls for Cvi-0 and Col-0 were most similar, while Th showed the greatest number of differences compared with the other controls. Compared with Col-0, however, Cvi-0 showed higher levels of expression of chaperones, receptor kinase-like and photosynthesis-related genes in ambient air. Cvi-0 exhibited ozone-mediated changes in a pathway involving AtSR, a homologue of the mammalian NF kappa B family of redox-sensitive transcription factors, changes in chaperones, WRKY and C2H2 proteins and antioxidants. WS displayed ozone-mediated decreases in the expression of two AtSR/NF kappa B family members, C2-domain proteins and genes associated with cell wall growth and changes in the expression of marker genes for programmed cell death (PCD), among them RCD1, a key regulator in this pathway. Microarray data were verified by reverse transcriptase (RT)-PCR. We relate O3-response diversity across the four lines to different responses among signaling and transcriptional response networks and differences in gene expression at [O3] levels. PMID:17087469

Li, Pinghua; Mane, Shrinivasrao P; Sioson, Allan A; Robinet, Cecilia Vasquez; Heath, Lenwood S; Bohnert, Hans J; Grene, Ruth

2006-05-01

293

40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.  

Science.gov (United States)

...Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387...Act for the 1997 8-hour ozone and PM2.5 National Ambient Air Quality...i) for the 1997 8-hour ozone and PM2.5 NAAQS. [73 FR 25518, May...

2010-07-01

294

Ozone production in the megacities of Tianjin and Shanghai, China: a comparative study  

OpenAIRE

Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical produc...

Lin, W. L.; Han, S. Q.; Lu, X. Q.; Han, M.; Xu, W. Y.; Zhao, C. S.; Ran, L.; Xu, X. B.; Gao, W.; Yu, Q.; Geng, F. H.; Ma, N.; Deng, Z. Z.; Chen, J.

2012-01-01

295

Utilization of ammonium as a nitrogen source: effects of ambient acidity on growth and nitrogen accumulation by soybean  

Science.gov (United States)

Dry matter accumulation of plants utilizing NH4+ as the sole nitrogen source generally is less than that of plants receiving NO3- unless acidity of the root-zone is controlled at a pH of about 6.0. To test the hypothesis that the reduction in growth is a consequence of nitrogen stress within the plant in response to effects of increased acidity during uptake of NH4+ by roots, nonnodulated soybean plants (Glycine max [L.] Merr. cv Ransom) were grown for 24 days in flowing nutrient culture containing 1.0 millimolar NH4+ as the nitrogen source. Acidities of the culture solutions were controlled at pH 6.1, 5.1, and 4.1 +/- 0.1 by automatic additions of 0.01 N H2SO4 or Ca(OH)2. Plants were sampled at intervals of 3 to 4 days for determination of dry matter and nitrogen accumulation. Rates of NH4+ uptake per gram root dry weight were calculated from these data. Net CO2 exchange rates per unit leaf area were measured on attached leaves by infrared gas analysis. When acidity of the culture solution was increased from pH 6.1 to 5.1, dry matter and nitrogen accumulation were reduced by about 40% within 14 days. Net CO2 exchange rates per unit leaf area, however, were not affected, and the decreased growth was associated with a reduction in rates of appearance and expansion of new leaves. The uptake rates of NH4+ per gram root were about 25% lower throughout the 24 days at pH 5.1 than at 6.1. A further increase in solution acidity from pH 5.1 to 4.1 resulted in cessation of net dry matter production and appearance of new leaves within 10 days. Net CO2 exchange rates per unit leaf area declined rapidly until all viable leaves had abscised by 18 days. Uptake rates of NH4+, which were initially about 50% lower at pH 4.1 than at 6.1 continued to decline with time of exposure until net uptake ceased at 10 days. Since these responses also are characteristic of the sequence of responses that occur during onset and progression of a nitrogen stress, they corroborate our hypothesis.

Tolley-Henry, L.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

1986-01-01

296

Ambient has become strained. Identification of Acacia dealbata Link volatiles interfering with germination and early growth of native species.  

Science.gov (United States)

Acacia dealbata Link is a widespread invader in Mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. Due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (VOCs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives Trifolium subterraneum, Lolium multiflorum, Medicago sativa, and also on its own seeds. We reported that VOCs from flowers significantly reduced germination in L. multiflorum and A. dealbata; moreover, root length, stem length, aboveground and belowground biomass were also reduced in all species studied. Volatile organic compounds from flowers and the mixture also increased significantly malondialdehyde content in T. subterraneum and L. multiflorum. The effects of VOCs on antioxidant enzymatic activities were species dependent. Flowers enhanced peroxidase but decreased superoxide dismutase activity in T. subterraneum. In contrast, VOCs released from leaves increased the activity of superoxide dismutase in L. multiflorum. GC/MS analyses revealed 27 VOCs in the volatile fraction from flowers, 12 of which were exclusive to this fraction. Within them, heptadecadiene, n-nonadecane, n-tricosane, and octadecene represent 62% of the fraction. We present evidence that the VOCs released from A. dealbata flowers strongly inhibited germination and seedling growth of selected species, and mainly on its own seedlings. As far as we know, this is the first evidence of phytotoxicity induced by VOCs in invasive species belonging to the Acacia genus. PMID:25260655

Souza-Alonso, Pablo; González, Luís; Cavaleiro, Carlos

2014-09-01

297

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...

298

Effects of ozone on growth, yield and leaf gas exchange rates of four Bangladeshi cultivars of rice (Oryza sativa L.)  

Energy Technology Data Exchange (ETDEWEB)

To assess the effects of tropospheric O{sub 3} on rice cultivated in Bangladesh, four Bangladeshi cultivars (BR11, BR14, BR28 and BR29) of rice (Oryza sativa L.) were exposed daily to charcoal-filtered air or O{sub 3} at 60 and 100 nl l{sup -1} (10:00-17:00) from 1 July to 28 November 2008. The whole-plant dry mass and grain yield per plant of the four cultivars were significantly reduced by the exposure to O{sub 3}. The exposure to O{sub 3} significantly reduced net photosynthetic rate of the 12th and flag leaves of the four cultivars. The sensitivity to O{sub 3} of growth, yield and leaf gas exchange rates was not significantly different among the four cultivars. The present study suggests that the sensitivity to O{sub 3} of yield of the four Bangladeshi rice cultivars is greater than that of American rice cultivars and is similar to that of Japanese rice cultivars and that O{sub 3} may detrimentally affect rice production in Bangladesh. - Bangladeshi cultivars of rice are sensitive to O{sub 3} below 100 ppb.

Akhtar, Nahid [United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Yamaguchi, Masahiro; Inada, Hidetoshi; Hoshino, Daiki; Kondo, Taisuke [Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Fukami, Motohiro [Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-8505 (Japan); Funada, Ryo [Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Izuta, Takeshi, E-mail: izuta@cc.tuat.ac.j [Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

2010-09-15

299

Ozone Inhalation Promotes CX3CR1-dependent Maturation of Resident Lung Macrophages which Limit Oxidative Stress and Inflammation1, 2  

OpenAIRE

Inhalation of ambient ozone alters populations of lung macrophages. However, the impact of altered lung macrophage populations on the pathobiology of ozone is poorly understood. We hypothesized that sub-populations of macrophages modulate the response to ozone. We exposed C57BL/6 mice to ozone (2 ppm × 3h) or filtered air. 24 h after the exposure, the lungs were harvested and digested and the cells underwent flow cytometry. Analysis revealed a novel macrophage subset present in ozone exposed...

Tighe, Robert M.; Li, Zhuowei; Potts, Erin N.; Frush, Sarah; Liu, Ningshan; Gunn, Michael D.; Foster, W. Michael; Noble, Paul W.; Hollingsworth, John W.

2011-01-01

300

Salud y medio ambiente: Health and environment  

Scientific Electronic Library Online (English)

Full Text Available 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.

2009-10-01

301

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

302

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

303

Secondary maxima in ozone profiles  

OpenAIRE

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

304

Growth analysis of sweet pepper cultivated in coconut fiber in a greenhouse / Análise de crescimento de pimentão cultivado em fibra de coco em ambiente protegido  

Scientific Electronic Library Online (English)

Full Text Available O conhecimento sobre o crescimento das culturas permite o planejamento de métodos de cultivo racional, que contribuirá para alcançar um maior potencial de espécies vegetais, além de fornecer informações para a construção de modelos matemáticos descritivos de crescimento. Diante disto, o objetivo des [...] te estudo foi determinar a curva de crescimento do pimentão amarelo (híbrido Eppo) cultivado em fibra de coco em ambiente protegido com fertirrigação. O experimento compreendeu inicialmente 160 plantas, divididas em quatro blocos, sendo colhidas duas por bloco a cada 21 dias após o transplante, finalizando-se aos 189 dias após o transplante. O cultivo de pimentão foi feito em vasos plásticos de 13 L contendo fibra de coco, distribuídos em fila dupla, com espaçamento de 0,5 x 0,8 m entre fileiras simples e 1,1 m entre fileiras duplas. Em cada colheita foram avaliados o crescimento das plantas e a produção e qualidade de frutos maduros. A massa seca da parte aérea aumentou com o tempo, seguindo um modelo exponencial de primeira ordem, atingindo um máximo de 451,5 g/planta aos 189 dias após o transplante (DAT). A produção de massa seca de folhas, caule, raiz e frutos também aumentou ao longo do tempo, seguindo o mesmo modelo, atingindo valores máximos de 68.7, 65.8, 11.5 e 302.9 g/planta, respectivamente, aos 189 DAT. O mesmo ocorreu com a área foliar por planta, altura da planta e a taxa de crescimento absoluto, cujos valores máximos foram de 6.183,5 cm², 136.9 cm e 4.4 g/planta/dia, respectivamente. O crescimento das plantas foi contínuo ao longo do ciclo, sendo que a maior quantidade de massa seca foi acumulada nos frutos, cuja produção comercial chegou a 97.3 t ha-1, sendo totalmente classificados como Extra. Abstract in english Knowledge about the growth of crops allows the planning of rational cultivation methods which contribute to achieve greater potential of plant species, besides supplying information for the construction of descriptive mathematical models of growth. The growth curve of sweet pepper (Eppo hybrid), cul [...] tivated in coconut fiber in a greenhouse with fertirrigation, was determined. The experiment consisted initially of 160 plants divided into four blocks. Two plants were analyzed per block every 21 days after transplanting, ending at 189 days after transplant. The cultivation was carried out in plastics pots of 13 L containing coconut fiber, which were arranged in double rows, spaced 0.5 x 0.8 m between simple rows and 1.1 m between double rows. In each harvest the plant growth, production and quality of mature fruits were evaluated. The dry mass of the shoot increased with time, following the experimental model exponential of first order, reaching a maximum of 451.5 g/plant, 189 days after transplanting (DAT). The production of dry mass of leaves, stem, root and fruit also increased over time reaching maximum values of 68.7, 65.8, 11.5 and 302.9 g/plant, respectively, at 189 DAT. The same occurred with the leaf area per plant, plant height and the absolute rate of growth, whose maximum values were 6.183,5 cm², 136.9 cm and 4.4 g/plant/day, respectively. The growth of the plant was continuous throughout the cycle, and the highest amount of dry mass was accumulated in fruits, reaching a marketable production of 97.3 t ha-1. All fruits were classified as Extra.

Hamilton César de O, Charlo; Sueyde F de, Oliveira; Renata, Castoldi; Pablo F, Vargas; Leila T, Braz; José Carlos, Barbosa.

2011-09-01

305

Assessment of Protective Effect of Some Modern Agrochemicals against Ozone-Induced Stress in Sensitive Clover and Tobacco Cultivars  

OpenAIRE

Some modern agrochemicals with antioxidant potential were tested for their protective effect against ozone injury using clover and tobacco ozone-sensitive cultivars as model plants subjected to ambient ozone at two sites (Kyiv city in Ukraine and Szarów village in Poland). All used agrochemicals showed partial protective effects against ozone injury on clover and tobacco. Conducted studies confirmed the effectiveness of modern fungicides belonging to strobilurin group as protectants of sensi...

Blum, Oleg; Didyk, Nataliya; Pavluchenko, Nataliya; Godzik, Barbara

2011-01-01

306

The effect of ozone associated with summertime photochemical smog on the frequency of asthma visits to hospital emergency departments  

Energy Technology Data Exchange (ETDEWEB)

A retrospective study using ambient ozone, temperature, and other environmental variables and their effect on the frequency of hospital visits for asthma was conducted in New Jersey, an area that often exceeds the allowable national standard for ozone. Data on emergency department visits for asthma, bronchitis, and finger wounds (a nonrespiratory control) were analyzed for the period May through August for 1988 and 1989. Asthma visits were correlated with temperature while the correlation between asthma visits and ozone concentration was nonsignificant. However, when temperature was controlled for in a multiple regression analysis, a highly significant relationship between asthma visits and ozone concentration was identified. Between 13 and 15% of the variability of the asthma visits and ozone concentration was identified. Between 13 and 15% of the variability of the asthma visits was explained in the regression model by temperature and ambient ozone levels. This association, when compared to similar studies in Canada, shows the contribution of ozone to asthma admissions to be stronger in areas with higher ozone concentrations. Thus, among regions with periodic accumulations of ozone in the ambient atmosphere, an exposure-response relationship may be discernible. This supports the need to attain air quality standards for ozone to protect individuals in the general population from the adverse health effects caused by ambient ozone exposure. 21 refs., 1 fig., 6 tabs.

Cody, R.P. (Robert Wood Johnson Medical School, Piscataway, NJ (United States)); Weisel, C.P.; Lioy, P.J. (Robert Wood Johnson Medical School, Piscataway, NJ (United States) Environmental and Occupational Health Sciences Institute, Piscataway, NJ (United States)); Birnbaum, G. (Morristown Memorial Hospital, NJ (United States))

1992-08-01

307

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

308

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

309

Ozone mass transfer and kinetics experiments  

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted at the Hanford Site to determine the most efficient pH and temperature levels for the destruction of complexants in Hanford high-level defense waste. These complexants enhance migration of radionuclides in the soil and inhibit the growth of crystals in the evaporator-crystallizer. Ozone mass transfer and kinetics tests have been outlined for the determination of critical mass transfer and kinetics parameters of the ozone-complexant reaction.

Bollyky, L.J.; Beary, M.M.

1981-12-01

310

Air Quality Guide for Ozone  

Science.gov (United States)

... Code: State : National Summary Air Quality Guide for Ozone Ground-level ozone is one of our nation’s ... seek alternative shelter. Key Facts to Know About Ozone: Ozone in the air we breathe can cause ...

311

Ambient intelligence  

CERN Document Server

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

Basten, Twan; de Groot, Harmke

2007-01-01

312

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.

Distributed Active Archive Center

313

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

314

Tropospheric ozone from satellite total ozone measurements  

Science.gov (United States)

A method for determining the amount of ozone in the tropical troposphere from concurrent sets of satellite data is presented. This procedure is applied only in the Tropics and the results indicate that a significant longitudinal gradient is present at low latitudes and that the highest amounts of tropospheric ozone are located west (i.e., downwind) of Africa and South America. Such a distribution suggests that biomass burning, or another stationary source of continental origin, is the largest source of ozone in the Tropics. The integrated amount of ozone in the Tropics that is derived from this analysis is comparable to or only slightly less than the amount of ozone that is present in northern mid latitudes. If such an interpretation is valid, then it suggests that the magnitude of the amount of tropospheric ozone resulting from in situ photochemical production in this region is comparable to the in situ photochemical source from industrialized emissions.

Fishman, Jack

1987-01-01

315

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

316

Physiological and foliar injury responses of Prunus serotina, Fraxinus americana, and Acer rubrum seedlings to varying soil moisture and ozone  

International Nuclear Information System (INIS)

High soil water availability favors ozone uptake, increases foliar injury, and exacerbates the negative ozone effect on gas exchange of seedlings of deciduous tree species. - Sixteen black cherry (Prunus serotina, Ehrh.), 10 white ash (Fraxinus americana, L.) and 10 red maple (Acer rubrum, L.) 1-year old seedlings were planted per plot in 1997 on a former nursery bed within 12 open-top chambers and six open plots. Seedlings were exposed to three different ozone scenarios (ambient air: 100% O3; non-filtered air: 98% ambient O3; charcoal-filtered air: 50% ambient O3) within each of two different water regimes (nine plots irrigated, nine plots non-irrigated) during three growing seasons. During the 1998 and 1999 growing season, leaf gas exchange, plant water relations, and foliar injury were measured. Climatic data, ambient- and chamber-ozone-concentrations were monitored. We found that seedlings grown under irrigated conditions had similar (in 1998) but significantly higher gas exchange rates (in 1999) than seedlings grown within non-irrigated plots among similar ozone exposures. Cherry and ash had similar ozone uptake but cherry developed more ozone-induced injury (<34% affected leaf area, LAA) than ash (<5% LAA), while maple rarely showed foliar injury, indicating the species differed in ozone sensitivity. Significantly more severe injury on seedlings grown under irrigated conditions than seedlings grown under non-irrigated conditions ings grown under non-irrigated conditions demonstrated that soil moisture altered seedling responses to ambient ozone exposures

317

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

OpenAIRE

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

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

    2009-01-01

318

Ozone and Your Health  

Science.gov (United States)

... and Your Health Particle Pollution Public Health Issues Ozone and Your Health Recommend on Facebook Tweet Share ... can be harmful to your health. How can ozone affect my health? If you have asthma, bronchitis, ...

319

Stratospheric Ozone  

Science.gov (United States)

The goal of this NASA Earth Science Enterprise-funded project is to increase the use of satellite data in high school and college science classrooms by developing classroom materials linked to guided inquiry computer exercises. This Stratospheric Ozone module is one of four Studying Earth's Environment from Space (SEES) modules. Each module consists of three sections: Class Resources, Computer Lab Resources and a Glossary and Acronym List. Class Resources is an electronic textbook viewable by a Web browser. Computer Lab Resources contain an instructor's guide, data and software. The instructor's guide contains exercises for using the data and software. The public domain software, a version of NIH-Image for the Macintosh that was modified by NASA Goddard Space Flight Center especially for SEES, is for data display, analysis and tutorial of satellite data. The software will also work on Windows machines with a Mac emulator. Image2000, a cross-platform Java version of the software, is expected to be available by the end of the year 2000. Each module section can stand-alone (e.g. you don't have to use the Class Resources in order to complete the Computer Lab Resources). Students and instructors may continue their own scientific discovery by accessing archived and current data from various NASA Earth Science data centers.

Blanche Meeson

320

Photochemistry of tropospheric ozone  

Science.gov (United States)

A photochemical equilibrium model of minor constituent chemistry in the troposphere was constructed to investigate the photochemistry of tropospheric ozone. We find that photochemical production must be supplemented by additional sources to account for observed ozone levels in clean air, while photochemical loss is more important than surface destruction as an ozone loss mechanism. Photochemically produced ozone is sensitive to the NO(x) background in the model, exhibiting a maximum of about 0.5 ppb of NO(x).

Stewart, R. W.; Hameed, S.; Pinto, J. P.

1977-01-01

321

Aura-OMI Ozone Hole from September 12, 2004 to November 15,2004  

Science.gov (United States)

Data from NASA satellites establishes a 40 year record of stratospheric ozone measurements. The stratospheric ozone layer shields life on Earth from harmful solar ultraviolet (UV) radiation. Research shows that excess exposure to UV radiation causes skin cancer and eye problems and impacts plant growth. Global stratospheric ozone has decreased by 3 percent globally between 1980 and 2000 and has thinned by 50 percent over Antarctica in winter and spring. Depletion of the ozone layer allows more UV radiation to reach the Earths surface. This animation shows the ozone layer blocking harmful UV radiation from the Earths surface. The hole in the ozone is seen in purple.

Lori Perkins

2004-12-13

322

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

323

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

324

OZONE BYPRODUCT FORMATION  

Science.gov (United States)

The use of ozone for water treatment has been increasing as ozone has great potential for degrading water pollutants and inactivating viruses, Giardia cysts, and Cryptosporidium oocysts. Although it appears that ozone generates less undesirable disinfection by-products (DBPs) th...

325

Manifestation of solar activity processes in the Earth ozone layer  

International Nuclear Information System (INIS)

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

326

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

327

Estrés oxidativo en un modelo de ratón quemado tratado con Aloe b, ozono y factor de crecimiento epidérmico / Oxidative stress in a model of burnt mouse treated with Aloe b, ozone and epidermal growth factor  

Scientific Electronic Library Online (English)

Full Text Available La enfermedad por quemadura estimula la respuesta inflamatoria sistémica y el daño múltiple de órganos, su expresión morfológica. Con el propósito de identificar el comportamiento del estrés oxidativo mediante el malondialdehído, la superóxido dismutasa y la catalasa y su modificación con el empleo [...] del tratamiento sistémico con Aloe b, ozono o factor de crecimiento epidérmico, se elaboró un modelo de quemadura seca de un área de 11 %, en ratones hembras, balb/c de 20 ± 2 g (n= 24). Se aplicó eutanasia en diferentes tiempos, se estudiaron los órganos con evaluación cualitativa en grados de intensidad y las variables bioquímicas se obtuvieron del riñón y del hígado. La prueba G se empleó para conocer la dependencia entre las variables y la prueba t se usó al comparar porcentajes. El análisis de varianza bifactorial y la prueba de rango múltiple de Duncan se empleó en las variables del estrés oxidativo estudiadas. Se siguieron las normas éticas en el trabajo con los animales. Existió dependencia entre los diferentes grupos y la vitalidad (G= 268,83***) superior en los grupos tratados. Los grupos no tratados tuvieron mayor intensidad del daño múltiple de órganos y peor respuesta del estrés oxidativo. Los grupos con mejor evolución fueron el tratado con ozono y el tratado con factor de crecimiento epidérmico. El tratamiento inmediatamente después de la quemadura con ozono y factor de crecimiento epidérmico resultó favorable para la evolución y supervivencia de los animales. Abstract in english Burn disease stimulates systemic inflammatory response and its morphologic expression that is multiple organ failure. With the objective of identifying the behaviour of oxidative stress through malonaldehyde, superoxide dismutase, and catalase, and its change by using the systemic treatment based on [...] Aloe b, ozone or epidermal growth factor, a dry burn model of a 11 % area in balb/c female mice of 20 ± 2 g (n= 24) was designed. Eutanasia was applied at different moments, organs were studied with qualitative evaluation of intensity degrees, and biochemical variables were analyzed from the kidney and the liver of mice. Test G served to find out dependence among variables and Test t was used to compare percentages. Bifactoral variance analysis and Duncan´s multiple range test were used in the studied oxidative stress variables. Ethical standards on work with animals were complied with. Dependence was observed among the various groups and survival rate (G= 268,83***) was higher in the treated groups. Untreated groups showed more intensive multiple organ damage and worse oxidative stress response. The groups treated with ozone and epidermal growth factor showed better recovery. The treatment with ozone and epidermal growth factor immediately after burning favored recovery and survival of balb/c mice.

Teresita, Montero González; José, Hurtado de Mendoza Amat; José Carlos, García Piñeiro; Niurka A., Llopiz Janer; Silvia, Menéndez Cepero; Jorge, Berlanga Acosta.

2006-09-01

328

Estrés oxidativo en un modelo de ratón quemado tratado con Aloe b, ozono y factor de crecimiento epidérmico Oxidative stress in a model of burnt mouse treated with Aloe b, ozone and epidermal growth factor  

Directory of Open Access Journals (Sweden)

Full Text Available La enfermedad por quemadura estimula la respuesta inflamatoria sistémica y el daño múltiple de órganos, su expresión morfológica. Con el propósito de identificar el comportamiento del estrés oxidativo mediante el malondialdehído, la superóxido dismutasa y la catalasa y su modificación con el empleo del tratamiento sistémico con Aloe b, ozono o factor de crecimiento epidérmico, se elaboró un modelo de quemadura seca de un área de 11 %, en ratones hembras, balb/c de 20 ± 2 g (n= 24. Se aplicó eutanasia en diferentes tiempos, se estudiaron los órganos con evaluación cualitativa en grados de intensidad y las variables bioquímicas se obtuvieron del riñón y del hígado. La prueba G se empleó para conocer la dependencia entre las variables y la prueba t se usó al comparar porcentajes. El análisis de varianza bifactorial y la prueba de rango múltiple de Duncan se empleó en las variables del estrés oxidativo estudiadas. Se siguieron las normas éticas en el trabajo con los animales. Existió dependencia entre los diferentes grupos y la vitalidad (G= 268,83*** superior en los grupos tratados. Los grupos no tratados tuvieron mayor intensidad del daño múltiple de órganos y peor respuesta del estrés oxidativo. Los grupos con mejor evolución fueron el tratado con ozono y el tratado con factor de crecimiento epidérmico. El tratamiento inmediatamente después de la quemadura con ozono y factor de crecimiento epidérmico resultó favorable para la evolución y supervivencia de los animales.Burn disease stimulates systemic inflammatory response and its morphologic expression that is multiple organ failure. With the objective of identifying the behaviour of oxidative stress through malonaldehyde, superoxide dismutase, and catalase, and its change by using the systemic treatment based on Aloe b, ozone or epidermal growth factor, a dry burn model of a 11 % area in balb/c female mice of 20 ± 2 g (n= 24 was designed. Eutanasia was applied at different moments, organs were studied with qualitative evaluation of intensity degrees, and biochemical variables were analyzed from the kidney and the liver of mice. Test G served to find out dependence among variables and Test t was used to compare percentages. Bifactoral variance analysis and Duncan´s multiple range test were used in the studied oxidative stress variables. Ethical standards on work with animals were complied with. Dependence was observed among the various groups and survival rate (G= 268,83*** was higher in the treated groups. Untreated groups showed more intensive multiple organ damage and worse oxidative stress response. The groups treated with ozone and epidermal growth factor showed better recovery. The treatment with ozone and epidermal growth factor immediately after burning favored recovery and survival of balb/c mice.

Teresita Montero González

2006-09-01

329

Interação genótipo-ambiente em algumas características produtivas de gado de corte no Brasil / Genotype environmental interaction in some growth traits of beef cattle in Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este estudo teve por objetivo medir o efeito da interação genótipo-ambiente (IGA) em algumas características de crescimento em bovinos Nelore. Os dados foram coletados em duas fazendas, em regiões distintas do Estado de Minas Gerais, Sul (faz I) e Noroeste (faz II), e correspondem aos pesos de 2.896 [...] animais à pré-desmama (PD), 2.605 à desmama (DM) e 1.522 à pós-desmama (SA), com 9.911 no arquivo de genealogia. Apenas animais criados em pasto foram utilizados para as análises. Os efeitos de época de nascimento (mês-ano), sexo e fazenda foram reunidos em grupos de contemporâneos. Os componentes de (co)variância foram estimados pelo programa MTDFREML. Nas análises conjuntas de duas características as estimativas de herdabilidade dos efeitos diretos foram 0,24, 0,16, e 0,17 (faz I) e 0,25, 0,24, e 0,17 (faz II), para PD, DM e SA, respectivamente. As correlações de ordem dos valores genéticos entre fazendas para as características PD, DM e SA foram, respectivamente, 0,74, 0,76 e 0,51. Na mesma ordem, as correlações genéticas entre fazendas foram 0,96, 0,95 e 0,53. Estes resultados não evidenciaram efeito da IGA até a desmama, porém após a desmama seu efeito foi grande, sugerindo que se deva fazer uma avaliação regional para escolha de reprodutores Nelore se se utilizar essa última característica como critério de seleção. Abstract in english The objective of this study was to measure the genotype-environment interaction (GEI) effect on some growth traits in Nellore cattle. Data from 2,896 records of pre-weaning (PW), 2,605 of weaning (WW) and 1,522 of post-yearling (YW) weights with a total of 9,911 pedigree animals from two farms of di [...] fferent regions of Minas Gerais State, South (farm I) and Northeast (farm II) were analyzed. Contemporary groups consider the effects of month-year of birth, sex, and herd. Only data from animals raised under pasture conditions were used. Covariance components were estimated by MTDFREML. Direct heritability obtained from bivariate analyses were 0.24, 0.16 and 0.17 (farm I) and 0.25, 0.24 and 0.17 (farm II) for PW, WW and YW, respectively. The ranking correlations between farms were 0.74, 0.76 and 0.51 and genetic correlations between farms were 0.96, 0.95 and 0.53 for PW, WW and YW, respectively. These results showed that there was no evidence of GEI up to weaning time but there was a significant effect of this interaction on the post-yearling weight. If selection criterion includes growth traits measured after weaning, regional evaluation should be recommended for bulls choice.

V.C.P., Ferreira; V.M., Penna; J.A.G., Bergmann; R.A., Torres.

2001-06-01

330

Interação genótipo-ambiente em algumas características produtivas de gado de corte no Brasil Genotype environmental interaction in some growth traits of beef cattle in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Este estudo teve por objetivo medir o efeito da interação genótipo-ambiente (IGA em algumas características de crescimento em bovinos Nelore. Os dados foram coletados em duas fazendas, em regiões distintas do Estado de Minas Gerais, Sul (faz I e Noroeste (faz II, e correspondem aos pesos de 2.896 animais à pré-desmama (PD, 2.605 à desmama (DM e 1.522 à pós-desmama (SA, com 9.911 no arquivo de genealogia. Apenas animais criados em pasto foram utilizados para as análises. Os efeitos de época de nascimento (mês-ano, sexo e fazenda foram reunidos em grupos de contemporâneos. Os componentes de (covariância foram estimados pelo programa MTDFREML. Nas análises conjuntas de duas características as estimativas de herdabilidade dos efeitos diretos foram 0,24, 0,16, e 0,17 (faz I e 0,25, 0,24, e 0,17 (faz II, para PD, DM e SA, respectivamente. As correlações de ordem dos valores genéticos entre fazendas para as características PD, DM e SA foram, respectivamente, 0,74, 0,76 e 0,51. Na mesma ordem, as correlações genéticas entre fazendas foram 0,96, 0,95 e 0,53. Estes resultados não evidenciaram efeito da IGA até a desmama, porém após a desmama seu efeito foi grande, sugerindo que se deva fazer uma avaliação regional para escolha de reprodutores Nelore se se utilizar essa última característica como critério de seleção.The objective of this study was to measure the genotype-environment interaction (GEI effect on some growth traits in Nellore cattle. Data from 2,896 records of pre-weaning (PW, 2,605 of weaning (WW and 1,522 of post-yearling (YW weights with a total of 9,911 pedigree animals from two farms of different regions of Minas Gerais State, South (farm I and Northeast (farm II were analyzed. Contemporary groups consider the effects of month-year of birth, sex, and herd. Only data from animals raised under pasture conditions were used. Covariance components were estimated by MTDFREML. Direct heritability obtained from bivariate analyses were 0.24, 0.16 and 0.17 (farm I and 0.25, 0.24 and 0.17 (farm II for PW, WW and YW, respectively. The ranking correlations between farms were 0.74, 0.76 and 0.51 and genetic correlations between farms were 0.96, 0.95 and 0.53 for PW, WW and YW, respectively. These results showed that there was no evidence of GEI up to weaning time but there was a significant effect of this interaction on the post-yearling weight. If selection criterion includes growth traits measured after weaning, regional evaluation should be recommended for bulls choice.

V.C.P. Ferreira

2001-06-01

331

Earth's ozone layer  

International Nuclear Information System (INIS)

The paper contain the actual results of investigations of the influence of the human activity on the Earth's ozone layer. History of the ozone measurements and of the changes in its concentrations within the last few years are given. The influence of the trace gases on both local and global ozone concentrations are discussed. The probable changes of the ozone concentrations are presented on the basis of the modelling investigations. The effect of a decrease in global ozone concentration on human health and on biosphere are also presented. (author). 33 refs, 36 figs, 5 tabs

332

Use of ozone to reduce molds in a cheese ripening room  

OpenAIRE

Cheese ripening rooms have an unusual environment, an environment that encourages mold growth. Ozone has been applied in various ways in the food industry. One useful advantage of ozone is that it inactivates molds. In this study, a cheese ripening room was ozonated, and the effectiveness of this treatment was evaluated both in air and on surfaces through sampling on a weekly basis over a 3-month period. The results obtained indicate that ozone treatment reduced the viable airborne mold load ...

Serra, Rita; Abrunhosa, Lui?s; Kozakiewicz, Z.; Vena?ncio, Armando; Lima, Nelson

2003-01-01

333

Intercontinental trans-boundary contributions to ozone-induced crop yield losses in the Northern Hemisphere  

OpenAIRE

Enhanced surface ozone concentrations are known to be harmful to vegetation, reducing crop growth and yields. Tropospheric ozone concentrations have increased steadily since pre-industrial times, driven by in-situ production from anthropogenic emissions of nitrogen oxides (NOx), CO and volatile organic compounds. Transport of ozone and its precursors between continents has been shown to contribute to surface ozone air quality exceedences in many regions of the Northern ...

Hollaway, M. J.; Arnold, S. R.; Challinor, A. J.; Emberson, L. D.

2011-01-01

334

Ozone pollution: rising concentrations despite French and EU efforts  

International Nuclear Information System (INIS)

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

335

Industrial emissions cause extreme urban ozone diurnal variability  

OpenAIRE

Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NOx = NO + NO2) lead to a dramatic diurnal variation of surface ozone (O3) in Houston, Texas. During the daytime, photochemical oxidation of volatile organic compounds catalyzed by NOx results in episodes of elevated ambient O3 levels significantly exceeding the National Ambient Air Quality Standard. The O3 production rate in Houston is significantly higher...

Zhang, Renyi; Lei, Wenfang; Tie, Xuexi; Hess, Peter

2004-01-01

336

The Ozone Hole Tour  

Science.gov (United States)

The Ozone Hole Tour is a concise survey of the ozone depletion problem presented in four sequential parts and utilizing maps, videos, and computer simulations to convey measurement and observation of the Antarctic ozone hole. Part I covers the history in detection of the ozone hole, the nature and formation of ozone, the general nature of the ozone hole, and current governmental measures intended to reduce ozone depletion. Part II details recent ozone loss over Antarctica with emphasis on satellite measurements. Part III explores the chemistry and meteorological phenomena associated with ozone loss. Lastly, Part IV presents chemical modeling efforts at the University of Cambridge. In addition to the various visualization media, certain terminology throughout the four sections is linked to an online glossary. Finally, a reference list [found under More Info on the main page] contains links to sites related to ozone measurement, general ozone information, environmental groups and campaigns, relevant institutions, and the Scientific Visualization Studio at the National Aeronautics and Space Administration (NASA).

337

Tropospheric Ozone, the Polluter  

Science.gov (United States)

This site provides a brief overview of ground-level ozone, also known as tropospheric ozone, where it is largely considered a pollutant and is often called bad ozone. It can damage living tissue and break down certain materials and longer exposure will increase the negative effects. Ozone is a naturally occurring gas found in the troposphere and other parts of the atmosphere where its concentrations are not uniform. However, the ozone that is a byproduct of certain human activities does become a problem at ground level and this is what we think of as bad ozone. The site discusses the negative effects of tropospheric ozone and has photographs of the damage to plants caused by it. The site serves as a reference and has links to two student activities.

338

Stratospheric Ozone, the Protector  

Science.gov (United States)

This site provides an overview of the ozone layer, the layer of life-protecting ozone found at the top of the stratosphere that is critical to life on earth as we know it because it protects living organisms from ultraviolet (uv) radiation. This radiation is present in natural outdoor light and can be blocked or filtered by various substances like ozone. The site provides a brief history of the discovery of the ozone hole and presents scientific evidence that ozone is destroyed in the stratosphere. Diagrams illustrate how some human-released chemicals, such as chlorofluorocarbons (CFCs), are speeding up the breakdown of ozone in the atmosphere and maps and graphs show the developing ozone hole. This site serves as a reference for and has links to three student activities.

339

Measurement of Ground Level Ozone at Different Locations  

Directory of Open Access Journals (Sweden)

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

Yasmen A. Mustafa

2012-01-01

340

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

341

Evidence of widespread effects of ozone on crops and (semi-)natural vegetation in Europe (1990 – 2006) in relation to AOT40– and flux-based risk maps  

OpenAIRE

Records of effects of ambient ozone pollution on vegetation have been compiled for Europe for the years 1990–2006. Sources include scientific papers, conference proceedings, reports to research funders, records of confirmed ozone injury symptoms and an international biomonitoring experiment coordinated by the ICP Vegetation. The latter involved ozone-sensitive (NC-S) and ozone-resistant (NC-R) biotypes of white clover (Trifolium repens L.) grown according to a common protocol an...

Mills, Gina; Hayes, Felicity; Simpson, David; Emberson, Lisa; Norris, David; Harmens, Harry; Buker, Patrick

2011-01-01

342

Effects of simulated acid rain and ozone on foliar chemistry of field-grown Pinus ponderosa seedlings and mature trees.  

Science.gov (United States)

We investigated the additive and interactive effects of simulated acid rain and elevated ozone on C and N contents, and the C:N ratio of one-year-old and current-year foliage of field-grown mature trees and their half-sib seedlings of a stress tolerant genotype of ponderosa pine. Acid rain levels (pH 5.1 and 3.0) were applied weekly to foliage only (no soil acidification or N addition), from January to April, 1992. Plants were exposed to two ozone levels (ambient and twice-ambient) during the day from September 1991 to November 1992. The sequential application of acid rain and elevated ozone mimicked the natural conditions. Twice-ambient ozone significantly decreased foliar N content (by 12-14%) and increased the C:N ratio of both one-year-old and current-year foliage of seedlings. Although similar ozone effects were also observed on one-year-old foliage of mature trees, the only statistically significant effect was an increased C:N ratio when twice-ambient ozone combined with pH 3.0 rain (acid rain by ozone interaction). Enhancing the effect of twice-ambient ozone in increasing the C:N ratio of one-year-old foliage of mature trees in June was the only significant effect of acid rain. PMID:15091457

Momen, B; Helms, J A

1996-01-01

343

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

344

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.

345

Aura Ozone Monitoring Garden Lithograph  

Science.gov (United States)

This lithograph describes where ozone is found, how it is formed, and the effects of ozone on biological processes. How and why NASA studies ozone is covered along with how individuals can monitor ground level (tropospheric) ozone by starting their own ozone-monitoring garden.

2006-06-23

346

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.

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

2013-12-01

347

DOES CHRONIC OZONE EXPOSURE LEAD TO LUNG DISEASE?  

Science.gov (United States)

The potential role of ozone in the induction of chronic lung diseases remains unclear. sing an ambient profile adopted from aerometric data from the Southwest Air Basin, rats were exposed to O3 for up to 18 months before assessments of pulmonary structure, function and biochemist...

348

MEASUREMENT OF OXIDANT PRECURSORS AND THEIR RELATIONSHIP TO OZONE FORMATION  

Science.gov (United States)

Measurements of 0600 to 0900 AM speciated NMOC compounds obtained from 19 urban areas located throughout the United States during a 1985 sampling program are presented. The cities sampled all experienced ozone levels above the National Ambient Air Quality Standard (NAAQS) of 0.12...

349

Ozone chemistry in aqueous solution : ozone decomposition and stabilisation  

OpenAIRE

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

350

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...

351

Impact of four years exposure to different levels of ozone, phosphorus and drought on chlorophyll, mineral nutrients, and stem volume of Norway spruce, Picea abies  

Energy Technology Data Exchange (ETDEWEB)

Saplings of one clone of Norway spruce, Picea abies (L.) Karst, were planted in 120 l pots in 1991 and exposed to three levels of ozone, two levels of phosphorus and two levels of water supply in 42 open-top chambers (OTCs), during 1992/996. The effects of pots and OTCs were also tested. Nutrient concentrations of the needles were not affected by ozone, while the low phosphorus supply (LP) and drought stress (D) treatments had significant effects on several mineral nutrients, e.g. phosphorus, calcium, magnesium, manganese, sulphur and boron. Ozone reduced the chlorophyll concentration in the 2- and 3-year-old needles in 1994 and 1995. The highest ozone concentration reduced the stem volumes (- 8%), as well as the stem lengths (- 5%), of the saplings in 1993 and 1994, after two and three years of exposure. After the fourth growing season this ozone-induced reduction in stem volume disappeared which might be caused by pot limitation. LP supply and D both caused large decreases in the stem volume and length. The needles from LP treatment had as high P concentration as 1.2 - 1.5 mg g{sup -1}, implying a need for increasing the critical value for phosphorus. The OTC enclosure stimulated the stem volume growth significantly compared to saplings growing in ambient plots. This was suggested to be attributed to the slightly higher temperature in the OTCs. The overall result is that ozone in southern Sweden is likely to have negative effects on Norway spruce trees, although much less than other environmental factors, e.g. water and phosphorus. (au)

Wallin, G.; Sellden, G.; Ottosson, S.; Medin, E.L.; Skaerby, L. [Goeteborg Univ., Botanical Inst., Dept. of Plant Physiology, Goeteborg (Sweden); Karlsson, P.E. [Swedish Environmental Research Inst., Goeteborg (Sweden); Pleijel, H. [Goeteborg Univ., Dept. of Applied Environmental Science, Goeteborg (Sweden)

2002-02-01

352

Ozone - Current Air Quality Index  

Science.gov (United States)

... 3/26/15: Updated Air Quality Guide for Ozone 2/03/15: Updated Ozone Facts webpage. more announcements Air Quality Basics Air Quality Index | Ozone | Particle Pollution | UV | Smoke from fires | What You ...

353

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

354

Ozone trends across the United States over a period of decreasing NOx and VOC emissions.  

Science.gov (United States)

In this work, we evaluate ambient ozone trends at urban, suburban, and rural monitoring sites across the United States over a period of decreasing NOx and VOC emissions (1998-2013). We find that decreasing ozone trends generally occur in the summer, in less urbanized areas, and at the upper end of the ozone distribution. Conversely, increasing ozone trends generally occur in the winter, in more urbanized areas, and at the lower end of the ozone distribution. The 95(th) percentile ozone concentrations decreased at urban, suburban, and rural monitors by 1-2 ppb/yr in the summer and 0.5-1 ppb/yr in the winter. In the summer, there are both increasing and decreasing trends in fifth percentile ozone concentrations of less than 0.5 ppb/yr at urban and suburban monitors, while fifth percentile ozone concentrations at rural monitors decreased by up to 1 ppb/yr. In the winter, fifth percentile ozone concentrations generally increased by 0.1-1 ppb/yr. These results demonstrate the large scale success of U.S. control strategies targeted at decreasing peak ozone concentrations. In addition, they indicate that as anthropogenic NOx emissions have decreased, the ozone distribution has been compressed, leading to less spatial and temporal variability. PMID:25517137

Simon, Heather; Reff, Adam; Wells, Benjamin; Xing, Jia; Frank, Neil

2015-01-01

355

Ozone and ozone injury on plants in and around Beijing, China  

International Nuclear Information System (INIS)

Ozone (O3) levels were assessed for the first time with passive samplers at 10 sites in and around Beijing in summer 2012. Average O3 concentrations were higher at locations around Beijing than in the city center. Levels varied with site locations and ranged from 22.5 to 48.1 ppb and were highest at three locations. Hourly O3 concentrations exceeded 40 ppb for 128 h and 80 ppb for 17 h from 2 to 9 in August at one site, where it had a real-time O3 analyzer. Extensive foliar O3 injury was found on 19 species of native and cultivated trees, shrubs, and herbs at 6 of the 10 study sites and the other 2 sites without passive sampler. This is the first report of O3 foliar injury in and around Beijing. Our results warrant an extensive program of O3 monitoring and foliar O3 injury assessment in and around Beijing. - Highlights: • Plants have been threatened by high O3 concentration in and around Beijing, China. • 19 plant species are reported as obvious ambient O3 injury symptoms in Beijing. • The O3 injury symptoms occur more often where ambient O3 concentration is higher. • The results warrant more extensive and long-term study of ambient O3 in China. - First report of ozone incidence and ozone injury on plants in and around Beijing, China

356

Stratosphere and ozone layer  

International Nuclear Information System (INIS)

Human activities disturb natural balance of earth atmosphere, in short time in comparison with time of great climatic evolutions of the past. Rapid destruction of ozone layer, modifications of chemical balances in Arctic by similar processes to which observed in Antarctic, first experimental views of ozone decreasing in stratosphere and increasing in troposphere, are indications of human perturbation in ozone layer balance which protect us from solar radiation. 17 figs., 6 tabs., 27 refs

357

The origin of ozone  

OpenAIRE

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 ...

Grewe, V.

2006-01-01

358

Status of ambient air quality at Barauni  

International Nuclear Information System (INIS)

Due to industrialization, Barauni has become a well developed industrial estate to be considered as industrial hub of Bihar. Contemporary to the industrial growth, the environmental quality also gradually deteriorated. Hence a need was felt to know the status of ambient air quality for proper planning of the future growth of industries. The ambient air quality was monitored at 16 stations in and around Barauni industrial estate during 3 major seasons for the period of one year. The results are discussed as to the status of the ambient air quality and suggestion have also been made for improvement. (author). 5 refs., 2 figs., 7 tabs

359

Evaluation of ozone trends and distribution in the Paso del Norte region using TCEQ's CAMS data and ozone data collected at two supplemental sites  

Science.gov (United States)

The purpose of this research was to determine whether the city of El Paso will continue to be in attainment if the Environmental Protection Agency (EPA) revises the National Ambient Air Quality Standards (NAAQS) of 8-hour average ozone concentration from 0.075 parts per million (ppm) to 0.070 ppm. For the duration of El Paso's ozone season, June-September 2012, two 2B Technology Ozone 202 monitors were deployed at proposed locations, not previously monitored. This was done in order to quantify concentration of ozone. In addition, ozone and meteorological data was downloaded from several Continuous Ambient Monitoring Stations (CAMS) in the Paso del Norte (PdN) region operated and maintained by Texas Commission of Environmental Quality (TCEQ). Daily maximum 1-hour and 8-hour average ozone concentrations were analyzed at each of all El Paso and Juarez CAM stations, and both supplemental sites. Both supplemental sites recorded high concentrations of ozone, demonstrating a potential need for an additional CAM station. The results did not exceed the allowable 8-hour average ozone level of 0.075 ppm but if the standard was lowered to 0.070 ppm the city will potentially be designated nonattainment.

Sandoval, Adrian Michael

360

Overt and Latent Cardiac Effects of Ozone Inhalation in Rats: Evidence for Autonomic Modulation and Increased Myocardial Vulnerability  

Science.gov (United States)

Background: Ozone (03) is a well-documented respiratory oxidant, but increasing epidemiologic evidence points to extra-pulmonary effects including positive associations between ambient 03 concentrations and cardiovascular morbidity/mortality. Objectives: With preliminary reports ...

361

Ozone, area social conditions, and mortality in Mexico City  

International Nuclear Information System (INIS)

We investigated whether the association of daily mortality and ambient ozone differs by age and area social conditions of the region of residence using a time-series analysis. The study setting was metropolitan Mexico City, a high altitude city situated in a valley, with an estimated 20 million inhabitants, large socioeconomic gradients, and ozone levels frequently exceeding international standards. We stratified daily deaths by six census-derived socioeconomic indicators, based on characteristics of the county where decedents lived. We used Poisson regression to model the association between daily mortality and ozone levels (on the day of death and the previous day) in separate models, stratified by area socioeconomic level and age, and controlling for time trends and temperature. Ozone was positively associated with total mortality [0.65% increase per 10 ppb increment, 95% confidence interval (CI): 0.02%, 1.28%] and for mortality among those over age 65 [1.39% increase per 10 ppb increment, 95% CI: 0.51%, 2.28%]. Associations between ozone and all-age mortality did not show any consistent patterns according to socioeconomic gradients. We conclude that elderly people are at higher risk for ozone-associated mortality. Though county-level social indicators in Mexico City were not strong markers of vulnerability to ozone-associated acute mortality in this analysis, complex associations between individual and area-level factors may exist that would require additional datay exist that would require additional data and further analyses to elucidate

362

Impact of transport and industrial emissions on the ambient air quality of Lahore City, Pakistan.  

Science.gov (United States)

Lahore's population is growing at a rate of 4% a year. It is widely perceived that because of this rapid growth, the level of services provided to the city's 7 million inhabitants has substantially deteriorated. This study presents the finding of ambient air quality monitoring carried out in Lahore City, Pakistan. The ambient air quality was monitored for criteria pollutants carbon monoxide (CO), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), ozone (O(3)), particulate matter (TSP and PM(10)), lead (Pb), and noise level at ten different locations of the city. The sampling locations were selected in a way to draw a representative profile of air quality, covering both newly developed as well as highly congested urban centers. The sulfur dioxide, lead, and suspended particulate concentration was found very high as compared to the ambient air quality standards of US Environmental Protection Agency and WHO guidelines. The 24-h average noise was exceeding the WHO limits at majority of the locations. The study presents the severity of air pollution in Lahore City, and findings would help city management to develop monitoring and mitigation measures to improve the air quality of the city. PMID:20052613

Ali, Mahboob; Athar, Makshoof

2010-12-01

363

Nucleation mode growth rates in Hyytiälä during 2003–2009: variation with particle size, season, data analysis method and ambient conditions  

OpenAIRE

The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the life time of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using parti...

Yli-juuti, T.; Nieminen, T.; Hirsikko, A.; Aalto, P. P.; Asmi, E.; Ho?rrak, U.; Manninen, H. E.; Patokoski, J.; Dal Maso, M.; Peta?ja?, T.; Rinne, J.; Kulmala, M.; Riipinen, I.

2011-01-01

364

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

OpenAIRE

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

365

Carbohydrate and carbon metabolite accumulation responses in leaves of ozone tolerant and ozone susceptible spinach plants after acute ozone exposure.  

Science.gov (United States)

The objective of this study was to determine whether exposure of plants to ozone (O3) increased the foliar levels of glucose, glucose sources, e.g., sucrose and starch, and glucose-6-phosphate (G6P), because in leaf cells, glucose is the precursor of the antioxidant, L-ascorbate, and glucose-6-phosphate is a source of NADPH needed to support antioxidant capacity. A further objective was to establish whether the response of increased levels of glucose, sucrose, starch and G6P in leaves could be correlated with a greater degree of plant tolerance to O3. Four commercially available Spinacia oleracea varieties were screened for tolerance or susceptibility to detrimental effects of O3 employing one 6.5 hour acute exposure to 25O nL O3 L(-1) air during the light. One day after the termination of ozonation (29 d post emergence), leaves of the plants were monitored both for damage and for gas exchange characteristics. Cultivar Winter Bloomsdale (cv Winter) leaves were least damaged on a quantitative grading scale. The leaves of cv Nordic, the most susceptible, were approximately 2.5 times more damaged. Photosynthesis (Pn) rates in the ozonated mature leaves of cv Winter were 48.9% less, and in cv Nordic, 66.2% less than in comparable leaves of their non-ozonated controls. Stomatal conductance of leaves of ozonated plants was found not to be a factor in the lower Pn rates in the ozonated plants. At some time points in the light, leaves of ozonated cv Winter plants had significantly higher levels of glucose, sucrose, starch, G6P, G1P, pyruvate and malate than did leaves of ozonated cv Nordic plants. It was concluded that leaves of cv Winter displayed a higher tolerance to ozone mediated stress than those of cv Nordic, in part because they had higher levels of glucose and G6P that could be mobilized during diminished photosynthesis to generate antioxidants (e.g., ascorbate) and reductants (e.g., NADPH). Elevated levels of both pyruvate and malate in the leaves of ozonated cv Winter suggested an increased availability of respiratory substrates to support higher respiratory capacity needed for repair, growth, and maintenance. PMID:24271929

Robinson, J M; Rowland, R A

1996-11-01

366

Yield and nutritive quality of sericea lespedeza (Lespedeza cuneata) and little bluestem (Schizachyrium scoparium) exposed to ground-level ozone  

International Nuclear Information System (INIS)

Ground-level ozone decreased the nutritive quality of select warm-season forages for ruminant herbivores. - Sericea lespedeza (Lespedeza cuneata cv. Interstate 76) and little bluestem (Schizachyrium scoparium cv. Aldous) were raised from seed in a glasshouse, transplanted into 5.7-l pots and placed into open-top chambers (OTC) on 6 June 1999. Following a 7-day adjustment period, each of six OTCs (duplicate OTCs per treatment) was ventilated with either air that had been carbon-filtered (CF) to remove ambient ozone (O3); non-filtered (NF), representative of ambient air; or enriched to twice-ambient O3 concentration (2X). Primary-growth forage was harvested on days 7, 32, 46, 59 and 72 following the start of fumigation, and regrowth forage from the first primary-growth harvest was harvested on days 36, 54 and 72 following the start of fumigation. Dry matter (DM) yield of either forage species did not differ among treatments except in the final regrowth period when yield of sericea lespedeza was greater for the NF than 2X O3 treatment. In vitro DM digestibility (IVDMD) and concentrations of crude protein (CP), soluble phenolics (SP) and condensed tannins (CT) in primary-growth sericea lespedeza did not differ between treatments, but NF primary-growth forage had higher concentration of protein-precipitating tannins (PPT) than did 2X primary-growth forage. Concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were higher in NF and 2X than in CF primary-growth sericea lespedeza. Similarly, concentrations of NDF and ADL were higher, and IVDMD was lower for NF and 2X than for CF regrowth sericea lespedeza. Concentrations of ADF and ADL were lower, whereas IVDMD, in vitro NDF digestibility (IVNDFD) and concentrations of CP and SP were greater, in CF than in NF and 2X primary-growth little bluestem. Percentages IVDMD and IVNDFD and concentrations of CP and SP in NF primary-growth little bluestem were greater than those in forage exposed to 2X O3 treatment. No significant differences were observed among treatments in percentages IVDMD and IVNDFD, or concentrations of cell wall constituents or SP in little bluestem regrowth. Nutritive quality of little bluestem was decreased by 3 levels can drive alterations in forage quality of select warm-season forages sufficient to have nutritional and economic implications for their utilization by ruminant herbivores

367

Crops' responses to ozone in Mediterranean environments  

International Nuclear Information System (INIS)

The Mediterranean environment, and most of the Italian peninsula, presents some peculiarities in terms of crop response to O3 since most physiological mechanisms activated upon O3 exposure, such as stomatal closure, often overlap and interact with those that underlie plant adaptation to drought and hyperosmotic stress, which are typical of these environments. OTC and EDU experiments have demonstrated that O3 causes strong yield losses when crops are grown without water limitations. However, exposure to water or saline stress significantly reduced O3 effects on crop yield. In this review, we present the methodological approaches that have been used to study plant-ozone interactions in Italy as well as biochemical, physiological and agronomic responses for representative cropping systems of the Mediterranean climate. - Is the 22% yield loss due to ambient ozone in non-limiting water conditions a realistic estimate for moderately stressed crops, typical of most Mediterranean regions?

368

Ground-Level Ozone  

Science.gov (United States)

Ground level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile ... the major sources of NOx and VOC. Breathing ozone can trigger a variety of health problems, particularly ...

369

Observing trends in total ozone and extreme ozone events  

Science.gov (United States)

The ozone layer in the stratosphere has been recovering since the 1989 Montreal Protocol reduced the use of ozone-destroying chlorofluorocarbons. Fitzka et al. observed trends in total ozone levels and the vertical distribution of ozone at Hoher Sonnblick, a mountain in Austria, from 1994 to 2011.

Balcerak, Ernie

2014-05-01

370

Effects of ambient and elevated CO2 on growth, chlorophyll fluorescence, photosynthetic pigments, antioxidants, and secondary metabolites of Catharanthus roseus (L.) G Don. grown under three different soil N levels.  

Science.gov (United States)

Catharanthus roseus L. plants were grown under ambient (375?±?30 ppm) and elevated (560?±?25 ppm) concentrations of atmospheric CO2 at different rates of N supply (without supplemental N, 0 kg N ha(-1); recommended N, 50 kg N ha(-1); and double recommended N, 100 kg N ha(-1)) in open top chambers under field condition. Elevated CO2 significantly increased photosynthetic pigments, photosynthetic efficiency, and organic carbon content in leaves at recommended (RN) and double recommended N (DRN), while significantly decreased total nitrogen content in without supplemental N (WSN). Activities of superoxide dismutase, catalase, and ascorbate peroxidase were declined, while glutathione reductase, peroxidase, and phenylalanine-ammonia lyase were stimulated under elevated CO2. However, the responses of the above enzymes were modified with different rates of N supply. Elevated CO2 significantly reduced superoxide production rate, hydrogen peroxide, and malondialdehyde contents in RN and DRN. Compared with ambient, total alkaloids content increased maximally at recommended level of N, while total phenolics in WSN under elevated CO2. Elevated CO2 stimulated growth of plants by increasing plant height and numbers of branches and leaves, and the magnitude of increment were maximum in DRN. The study suggests that elevated CO2 has positively affected plants by increasing growth and alkaloids production and reducing the level of oxidative stress. However, the positive effects of elevated CO2 were comparatively lesser in plants grown under limited N availability than in moderate and higher N availability. Furthermore, the excess N supply in DRN has stimulated the growth but not the alkaloids production under elevated CO2. PMID:25304238

Singh, Aradhana; Agrawal, Madhoolika

2015-03-01

371

Two Years of Ozone Vertical Profiles Collected from Aircraft over California and the Pacific Ocean  

Science.gov (United States)

Tropospheric ozone transported across the Pacific Ocean has been strongly suggested to contribute substantially to surface ozone levels at several sites within Northern California's Sacramento Valley. Because this contribution can affect a city's ability to meet regulatory ozone limits, the influence of Pacific ozone transport has implications for air quality control strategies in the San Joaquin Valley (SJV). The Alpha Jet Atmospheric Experiment is designed to collect a multi-year data set of tropospheric ozone vertical profiles. Forty-four flights with ozone profiles were conducted between February 2nd, 2011 and August 9th, 2012, and approximately ten more flights are expected in the remainder of 2012. Twenty marine air profiles have been collected at sites including Trinidad Head and two locations tens of kilometers offshore at 37° N latitude. Good agreement is seen with ozonesondes launched from Trinidad Head. Additional profiles over Merced, California were obtained on many of these flight days. These in-situ measurements were conducted during spiral descents of H211's Alpha Jet at mid-day local times using a 2B Technologies Dual Beam Ozone Monitor. Hourly surface ambient ozone data were obtained from the California Air Resources Board's SJV monitoring sites. For each site, the Pearson linear correlation coefficient was calculated between ozone in a 300m vertical layer of an offshore profile and the surface site at varying time offsets from the time of the profile. Each site's local and regional ozone production component was estimated and removed. The resulting correlations suggest instances of Pacific ozone transport following some of the offshore observations. Real-Time Air Quality Modeling System (RAQMS) products constrained by assimilated satellite data model the transport of ozone enhancements and guide flight planning. RAQMS hindcasts also suggest that ozone transport to the surface of the SJV basin occurred following some of these offshore profiles. Ensemble back trajectories along the flight tracks and Reverse Domain Filling maps and curtains will be analyzed to further evaluate ozone transport pathways.

Austerberry, D.; Yates, E. L.; Roby, M.; Chatfield, R. B.; Iraci, L. T.; Pierce, B.; Fairlie, T. D.; Johnson, B. J.; Ives, M.

2012-12-01

372

Estonian total ozone climatology  

Directory of Open Access Journals (Sweden)

Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

K. Eerme

373

Fundamentals of ISCO Using Ozone  

Science.gov (United States)

In situ chemical oxidation (ISCO) using ozone involves the introduction of ozone gas (O3) into the subsurface to degrade organic contaminants of concern. Ozone is tri-molecular oxygen (O2) that is a gas under atmospheric conditions and is a strong oxidant. Ozone may react with ...

374

Visible foliar injury and infrared imaging show that daylength affects short-term recovery after ozone stress in Trifolium subterraneum  

OpenAIRE

Tropospheric ozone is a major air pollutant affecting plants worldwide. Plants in northern regions can display more ozone injury than plants at lower latitudes despite lower ozone levels. Larger ozone influx and shorter nights have been suggested as possible causes. However, the effects of the dim light present during northern summer nights have not been investigated. Young Trifolium subterraneum plants kept in environmentally controlled growth rooms under long day (10?h bright light, 14?...

Vollsnes, Ane V.; Eriksen, Aud Berglen; Otterholt, Eli; Kvaal, Knut; Oxaal, Unni; Futsaether, Cecilia M.

2009-01-01

375

Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study  

Science.gov (United States)

Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various non-methane hydrocarbons (NMHCs). Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. High ozone concentrations (>80 ppbv) of long duration (>6h) were frequently encountered in both urban and suburban Tianjin, while the occurrence of high ozone concentrations lasted for a shorter period (usually ozone production rates upon NMHC reactivity. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

Ran, Liang; Zhao, Chunsheng

2013-04-01

376

Ozone lidar monitoring  

International Nuclear Information System (INIS)

An ozone lidar system was installed at the National Institute for Environmental Studies (36 deg. N, 140 deg. E) in March, 1988 and observation of ozone profiles commenced from August 1988. The lidar system consists of XeCl, XeF and KrF excimer lasers, 2 m and 56 cm telescope optics and data processing systems. Since the Ozone Lidar Monitoring Program of the Center for the Environmental Research started in October 1990, frequent measurements (more than 50 times per year) have been made. After checking the statistical and systematic errors, the ozone profiles were archived. Comparisons between the lidar data and SAGE II satellite data were done for mutual validation and gave good results. Seventy four vertical profiles of ozone archived for the period from August 1990 through December 1991 are presented in this report. The seasonal and altitudinal variations of stratospheric ozone distribution can be explained by generally understood transport and photochemical reaction processes. Longer term monitoring is required to detect trends in the vertical profile of ozone

377

Atmospheric emissions and economic growth. Environmental Kuznets Curve and Kyoto protocol; Emisiones atmosfericas y crecimiento economico en Espana. La Curve de Kuznets ambiental y el protocolo de Kyoto  

Energy Technology Data Exchange (ETDEWEB)

From the beginning of the 90s the analysis of the relationships between economic growth and environmental pressures has been influenced by the Environmental Kuznets Curve hypothesis or inverted-U shaped relationship between environmental pressure and per capita income. Following this hypothesis, once achieved certain income level, more economic growth is followed by environmental quality improvement. In this paper, we analyse and discuss the theories that support this hypothesis as well as the empirical evidence on this subject. Further on we analyse the relationship between per capita income and the main environmental pollutants for the case does not support the hypothesis. The empirical evidence shows that economic growth, by itself, does not entail a pollution reduction. (Author) 35 refs.

Roca Jusmet, J.; Padilla Rosa, E.

2004-07-01

378

Impacts of uncertainty in AVOC emissions on the summer RO x budget and ozone production rate in the three most rapidly-developing economic growth regions of China  

Science.gov (United States)

High levels of uncertainty in non-methane volatile organic compound (NMVOC) emissions in China could lead to significant variation in the budget of the sum of hydroxyl (OH) and peroxy (HO2, RO2) radicals (RO x = OH + HO2 + RO2) and the ozone production rate [P(O3)], but few studies have investigated this possibility, particularly with three-dimensional air quality models. We added diagnostic variables into the WRF-Chem model to assess the impact of the uncertainty in anthropogenic NMVOC (AVOC) emissions on the RO x budget and P(O3) in the Beijing-Tianjin-Hebei region, Yangtze River Delta, and Pearl River Delta of China. The WRF-Chem simulations were compared with satellite and ground observations, and previous observation-based model studies. Results indicated that 68% increases (decreases) in AVOC emissions produced 4%-280% increases (2%-80% decreases) in the concentrations of OH, HO2, and RO2 in the three regions, and resulted in 35%-48% enhancements (26%-39% reductions) in the primary RO x production and ˜ 65% decreases (68%-73% increases) of the P(O3) in Beijing, Shanghai, and Guangzhou. For the three cities, the two largest contributors to the RO x production rate were the reaction of O1D + H2O and photolysis of HCHO, ALD2, and others; the reaction of OH + NO2 (71%-85%) was the major RO x sink; and the major contributor to P(O3) was the reaction of HO2 + NO (˜ 65%). Our results showed that AVOC emissions in 2006 from Zhang et al. (2009) have been underestimated by ˜ 68% in suburban areas and by > 68% in urban areas, implying that daily and hourly concentrations of secondary organic aerosols and inorganic aerosols could be substantially underestimated, and cloud condensation nuclei could be underestimated, whereas local and regional radiation was overestimated.

Wang, Feng; An, Junling; Li, Ying; Tang, Yujia; Lin, Jian; Qu, Yu; Chen, Yong; Zhang, Bing; Zhai, Jing

2014-11-01

379

Artificial ozone holes  

CERN Document Server

This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

Dolya, S N

2014-01-01

380

Exposure to moderate concentrations of tropospheric ozone impairs tree stomatal response to carbon dioxide  

International Nuclear Information System (INIS)

With rising concentrations of both atmospheric carbon dioxide (CO2) and tropospheric ozone (O3), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO2 and O3, singly and in combination, on the primary short-term stomatal response to CO2 concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO2 and/or O3 exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO2 concentration from current ambient level. The impairement of the stomatal CO2 response by O3 most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO2 may not hold for northern hardwood forests under concurrently rising tropospheric O3. - Exposure to moderate concentrations of tropospheric ozone impairs stomatal CO2 responsiveness of birch in the Aspen FACE experiment.

381

Exposure to moderate concentrations of tropospheric ozone impairs tree stomatal response to carbon dioxide  

Energy Technology Data Exchange (ETDEWEB)

With rising concentrations of both atmospheric carbon dioxide (CO{sub 2}) and tropospheric ozone (O{sub 3}), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO{sub 2} and O{sub 3}, singly and in combination, on the primary short-term stomatal response to CO{sub 2} concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO{sub 2} and/or O{sub 3} exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO{sub 2} concentration from current ambient level. The impairement of the stomatal CO{sub 2} response by O{sub 3} most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO{sub 2} may not hold for northern hardwood forests under concurrently rising tropospheric O{sub 3}. - Exposure to moderate concentrations of tropospheric ozone impairs stomatal CO{sub 2} responsiveness of birch in the Aspen FACE experiment.

Onandia, Gabriela [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden); Cavanilles Institute of Biodiversity and Evolutionary Biology, Department of Microbiology and Ecology, University of Valencia, E-46100 Burjassot, Valencia (Spain); Olsson, Anna-Karin; Barth, Sabine [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden); King, John S. [Department of Forestry and Environmental Resources, Campus Box 8002, North Carolina State University, Raleigh, NC 27695 (United States); Uddling, Johan, E-mail: johan.uddling@dpes.gu.se [Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30 Goeteborg (Sweden)

2011-10-15

382

Effect of ozone on respiratory responses in subjects with asthma  

Energy Technology Data Exchange (ETDEWEB)

In the process of understanding the respiratory effects of individual air pollutants, it is useful to consider which populations seem to be most susceptible to the exposures. Ozone is the most ubiquitous air pollutant in the United States, and there is great interest in the extent of susceptibility to this air pollutant. This review presents evidence that individuals with asthma are more susceptible to adverse respiratory effects from ozone exposure than are nonasthmatic individuals under similar circumstances. In studies comparing patients with asthma to nonasthmatic subjects, research has shown increased pulmonary-function decrements, an increased frequency of bronchial hyperresponsiveness in ozone responders, increased signs of upper airway inflammation after ozone exposure, and an increased response to inhaled sulfur dioxide or allergen in the subjects with asthma. Subjects with asthma are indeed a population susceptible to the inhaled effects of ozone. These data need to be considered by regulators who are charged with setting air quality standards to protect even the most susceptible members of the population. They also underline the importance of strategies to reduce human exposure to ambient ozone. 16 refs., 1 fig.

Koenig, J.Q. [Univ. of Washington, Seattle, WA (United States)

1995-03-01

383

The potential near-source ozone impacts of upstream oil and gas industry emissions.  

Science.gov (United States)

Increased drilling in urban areas overlying shale formations and its potential impact on human health through decreased air quality make it important to estimate the contribution of oil and gas activities to photochemical smog. Flares and compressor engines used in natural gas operations, for example, are large sources not only of NOx but also offormaldehyde, a hazardous air pollutant and powerful ozone precursor We used a neighborhood scale (200 m horizontal resolution) three-dimensional (3D) air dispersion model with an appropriate chemical mechanism to simulate ozone formation in the vicinity ofa hypothetical natural gas processing facility, based on accepted estimates of both regular and nonroutine emissions. The model predicts that, under average midday conditions in June, regular emissions mostly associated with compressor engines may increase ambient ozone in the Barnett Shale by more than 3 ppb beginning at about 2 km downwind of the facility, assuming there are no other major sources of ozone precursors. Flare volumes of 100,000 cubic meters per hour ofnatural gas over a period of 2 hr can also add over 3 ppb to peak 1-hr ozone somewhatfurther (>8 km) downwind, once dilution overcomes ozone titration and inhibition by large flare emissions of NOx. The additional peak ozone from the hypothetical flare can briefly exceed 10 ppb about 16 km downwind. The enhancements of ambient ozone predicted by the model are significant, given that ozone control strategy widths are of the order of a few parts per billion. Degrading the horizontal resolution of the model to 1 km spuriously enhances the simulated ozone increases by reducing the effectiveness of ozone inhibition and titration due to artificial plume dilution. PMID:22916444

Olaguer, Eduardo P

2012-08-01

384

The Effect of Air Pollution on Ozone Layer Thickness in Troposphere over the State of Kuwait  

Directory of Open Access Journals (Sweden)

Full Text Available Troposphere ozone layer acts as a shield against all ultraviolet radiation approaching the planet Earth through absorption. It was noticed in mid 80s that ozone layer has thinned on the poles of the planet due to release of man-made substances commonly known as Ozone Depleting Substances, (ODS into its atmosphere. The consequences of this change are adverse as the harmful radiations reach to the surface of the earth, strongly influencing the crops yield and vegetation. These radiations are major cause of skin cancer that has long exposure to Ultra Violet (UV radiation. United States environmental protection agency and European community have imposed strict regulations to curb the emission of ODS and phase out schedules for the manufacture and use of ODS that was specified by Montreal protocol in 1987. Problem statement: This research deled with data analysis of ozone layer thickness obtained from Abu-Dhabi station and detailed measurement of air pollution levels in Kuwait. Approach: The ozone layer thickness in stratosphere had been correlated with the measured pollution levels in the State of Kuwait. The influence of import of ozone depletion substances for the last decade had been evaluated. Other factor that strongly affects the ozone layer thickness in stratosphere is local pollution levels of primary pollutants such as total hydrocarbon compounds and nitrogen oxides. Results: The dependency of ozone layer thickness on ambient pollutant levels presented in detail reflecting negative relation of both non-methane hydrocarbon and nitrogen oxide concentrations in ambient air. Conclusion: Ozone layer thickness in stratosphere had been measured for five years (1999-2004 reflecting minimum thickness in the month of December and maximum in the month of June. The ozone thickness related to the ground level concentration of non-methane hydrocarbon and can be used as an indicator of the health of ozone layer thickness in the stratosphere.

H. O. Al Jeran

2009-01-01

385

Evidências de interação genótipo x ambiente sobre características de crescimento em bovinos de corte / Evidences of genotype x environment interaction for growth traits in beef cattle  

Scientific Electronic Library Online (English)

Full Text Available Objetivou-se, com este trabalho, estudar a interação genótipo x ambiente sobre os pesos à desmama (PD) e aos 12 meses de idade (P12), o ganho de peso diário da desmama aos 12 meses de idade (GDA) e o desempenho com base em um índice (CPG) de componentes principais envolvendo essas três característic [...] as, em um rebanho da raça Canchim. O ambiente foi considerado a época de nascimento (primeiro e segundo semestres) do animal. Para avaliar a interação genótipo x ambiente, foram utilizadas duas metodologias: 1 - estimativas de parâmetros genéticos pelo método da máxima verossimilhança restrita livre de derivadas (REML), com análise bicaráter (mesma característica nas duas épocas), com o modelo estatístico incluindo os efeitos fixos de sexo, ano e mês de nascimento do animal e idade da vaca ao parto como covariável (linear e quadrático) e os efeitos aleatórios de animal e do resíduo; e 2 - semelhante à metodologia 1, porém, no modelo estatístico, incluiu-se ou não o efeito aleatório não correlacionado de touro-época de nascimento, testando a diferença entre os dois modelos pelo teste de razão de verossimilhança. Pela Metodologia 1, as correlações genéticas obtidas para a mesma característica nas duas épocas de nascimento foram iguais a 0,87; 0,97; 0,91 e 0,88, para PD, P12, GDA e CPG, respectivamente. As estimativas de herdabilidade obtidas foram semelhantes para as duas épocas de nascimento, para todas as características estudadas. Pela metodologia 2, o efeito de touro-época de nascimento foi significativo para todas as características estudadas. Estes resultados evidenciam a existência de interação genótipo x época de nascimento para as características estudadas, sugerindo que as avaliações genéticas e a seleção dos animais desse rebanho devem considerar essa interação. Abstract in english The objective of this study was to evaluate the genotype x environment interaction for body weight at weaning (WW) and 12 months of age (W12), average daily gain from weaning to 12 months of age (ADG), and performance based on a principal components index (PC) involving these three traits, in a Canc [...] him (5/8 Charolais + 3/8 Zebu) herd. The environment was the season (semester) of birth, and two methods were used to evaluate the genotype x environment interaction: Method 1 - genetic parameters estimated by the derivative free maximum likelihood method (REML), using two-trait analyses (the same trait in the two seasons), and a model that included the effects of year and month of birth, sex and age of cow as a covariate (linear and quadratic effects), and the random effect of animal; and Method 2 - same methodology as Method 1, but with two statistical models, with or without the uncorrelated random effect of sire - season of birth, testing the difference between the two models using the likelyhood ratio test. By Method 1, the genetic correlations for the same trait in the two environments (seasons) were equal to 0.87, 0.97, 0.91 and 0.88 for WW, W12, ADG and PC, respectively. The heritability estimates were very similar for both environments, for all traits studied. By Method 2, the sire-season of birth effect was significant for all traits studied. These results show evidence of genotype x season of birth interaction for the traits studied, suggesting that, in this herd, genetic evaluation and selection should take this interaction into account.

Maurício Mello de, Alencar; Arthur dos Santos, Mascioli; Alfredo Ribeiro de, Freitas.

2005-04-01

386

Evidências de interação genótipo x ambiente sobre características de crescimento em bovinos de corte Evidences of genotype x environment interaction for growth traits in beef cattle  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivou-se, com este trabalho, estudar a interação genótipo x ambiente sobre os pesos à desmama (PD e aos 12 meses de idade (P12, o ganho de peso diário da desmama aos 12 meses de idade (GDA e o desempenho com base em um índice (CPG de componentes principais envolvendo essas três características, em um rebanho da raça Canchim. O ambiente foi considerado a época de nascimento (primeiro e segundo semestres do animal. Para avaliar a interação genótipo x ambiente, foram utilizadas duas metodologias: 1 - estimativas de parâmetros genéticos pelo método da máxima verossimilhança restrita livre de derivadas (REML, com análise bicaráter (mesma característica nas duas épocas, com o modelo estatístico incluindo os efeitos fixos de sexo, ano e mês de nascimento do animal e idade da vaca ao parto como covariável (linear e quadrático e os efeitos aleatórios de animal e do resíduo; e 2 - semelhante à metodologia 1, porém, no modelo estatístico, incluiu-se ou não o efeito aleatório não correlacionado de touro-época de nascimento, testando a diferença entre os dois modelos pelo teste de razão de verossimilhança. Pela Metodologia 1, as correlações genéticas obtidas para a mesma característica nas duas épocas de nascimento foram iguais a 0,87; 0,97; 0,91 e 0,88, para PD, P12, GDA e CPG, respectivamente. As estimativas de herdabilidade obtidas foram semelhantes para as duas épocas de nascimento, para todas as características estudadas. Pela metodologia 2, o efeito de touro-época de nascimento foi significativo para todas as características estudadas. Estes resultados evidenciam a existência de interação genótipo x época de nascimento para as características estudadas, sugerindo que as avaliações genéticas e a seleção dos animais desse rebanho devem considerar essa interação.The objective of this study was to evaluate the genotype x environment interaction for body weight at weaning (WW and 12 months of age (W12, average daily gain from weaning to 12 months of age (ADG, and performance based on a principal components index (PC involving these three traits, in a Canchim (5/8 Charolais + 3/8 Zebu herd. The environment was the season (semester of birth, and two methods were used to evaluate the genotype x environment interaction: Method 1 - genetic parameters estimated by the derivative free maximum likelihood method (REML, using two-trait analyses (the same trait in the two seasons, and a model that included the effects of year and month of birth, sex and age of cow as a covariate (linear and quadratic effects, and the random effect of animal; and Method 2 - same methodology as Method 1, but with two statistical models, with or without the uncorrelated random effect of sire - season of birth, testing the difference between the two models using the likelyhood ratio test. By Method 1, the genetic correlations for the same trait in the two environments (seasons were equal to 0.87, 0.97, 0.91 and 0.88 for WW, W12, ADG and PC, respectively. The heritability estimates were very similar for both environments, for all traits studied. By Method 2, the sire-season of birth effect was significant for all traits studied. These results show evidence of genotype x season of birth interaction for the traits studied, suggesting that, in this herd, genetic evaluation and selection should take this interaction into account.

Maurício Mello de Alencar

2005-04-01

387

75 FR 2938 - National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...L.; Thomas, D.; Dominici, F.; Samet, J. M.; Schwartz, J.; Dockery, D.; Cohen, A. (2000) Exposure measurement error in time...mice. Exp. Lung Res. 21: 503-518. Zidek, J. V.; White, R.; Le, N. D.;...

2010-01-19

388

HYDROCARBON AND CARBONYL OZONE PRECURSORS IN MEXICO CITY AMBIENT AIR  

Science.gov (United States)

Urban air pollution is an environmental problem in many cities around the world that has serious immediate and long-term implications to the health of the population and to the physical environment. Mexico City, in particular, faces a severe air pollution problem. The city is...

389

Numerical Simulation of Coastal Effects on Ozone Distributions in Tampa Bay, Florida.  

Science.gov (United States)

During the period July 22-24, 1987, the Tampa Bay area in Florida experienced the worst exceedance of the ozone ambient air quality standard (AAQS) since 1980. A mesoscale meteorological model (MM4) was used to simulate the complex meteorological conditions existing for the peninsula. The meteorological data obtained from the MM4 simulations were incorporated into a photochemical model (STEM-II) to simulate chemical variables. The model could predict the observed ozone concentrations at monitoring sites relatively well in terms of daytime ozone levels and peak ozone concentrations. The average peak prediction accuracy between daytime predicted and observed ozone levels during the episode for ozone data unpaired in time and site location (-13%), and the normalized bias (-14%) and error (26%) for data paired in time and space achieved the ozone model performance goals recommended by the California Air Research Board. Back trajectory analyses suggested that emissions from coastal urban areas in southeast and southwest Florida contributed to the ozone exceedances in the Tampa Bay area. On the basis of forward trajectory analyses, the air masses containing peak ozone concentrations on July 23, 1987, in Hillsborough and Pinellas counties each contributed to excessive ozone levels in adjacent counties as a result of transport processes. On 24th July, peak ozone concentrations in Hillsborough county were transported over Pinellas County to the Gulf. Results from these numerical model simulations suggested that VOC (Volatile Organic Compound) control alone is an appropriate strategy for meeting present and future O_3 compliance standards in the Tampa Bay area. Reduction in VOC emissions could have reduced maximum ozone levels to meet the ozone standard for the meteorological conditions existing on July 23, 1987, but could not have resolved the O_3 non-attainment problems existing on July 24, 1987. On the basis of emission reduction simulations, a statewide VOC reduction plan is recommended as a reasonable emission control strategy for the future.

Yeh, Junne-Yih Robert

390

The effect of ozone on pollen development in Lolium perenne L  

International Nuclear Information System (INIS)

Perennial ryegrass plants (Lolium perenne L.) were exposed in 'Closed-Top Chambers' to different ozone concentrations and to charcoal filtered ambient air to study the effect of ozone on the development of pollen. Ozone at ambient (65 nl l-1, 8 h) and elevated (110 nl l-1, 4 h) concentrations affected the maturing of pollen by inhibiting starch accumulation in pollen throughout the anther. Affected pollen persisted in the vacuolated state while normal pollen in the same anther were filled with amyloplasts. The percentage of underdeveloped pollen--determined in transversal sections--was significantly higher in exposed plants than in plants grown in filtered air. Results indicate that ozone stress was responsible for the disrupted development of pollen in L. perenne

391

High-latitude ozone loss outside the Antarctic ozone hole  

International Nuclear Information System (INIS)

Data taken during the 1987 Antarctic Airborne Ozone Experiment based in Punta Arenas, Chile, are used to show that from mid-August until the end of the mission in late September there was a high latitude ozone loss outside the Antarctic ozone hole. Therefore, not only is the geographic extent of the ozone loss larger than that generally identified as chemically perturbed, but ozone is lost earlier in the year than previously reported. These results, when compared with long-term temporal trends of column ozone, indicate a possible anthropogenic component for this loss. 30 refs., 4 figs

392

High-latitude ozone loss outside the Antarctic ozone hole  

Science.gov (United States)

Data taken during the 1987 Antarctic Airborne Ozone Experiment based in Punta Arenas, Chile, are used to show that from mid-August until the end of the mission in late September there was a high-latitude ozone loss outside the Antarctic ozone hole. Therefore, not only is the geographic extent of the ozone loss larger than that generally identified as chemically perturbed, but ozone is lost earlier in the year than previously reported. These results, when compared with long-term temporal trends of column ozone, indicate a possible anthropogenic component for this loss.

Proffitt, M. H.; Fahey, D. W.; Kelly, K. K.; Tuck, A. F.

1989-11-01

393

Ozone curbs crown rust  

Energy Technology Data Exchange (ETDEWEB)

Crown rust, the most destructive disease of oats, was suppressed in laboratory fumigation chambers by ozone air pollution levels commonly surpassed in many areas. Whether the effects of air pollution on crown rust are of economic importance under field conditions is yet to be determined. Crown rust, caused by the fungus Puccinia coronata, is particularly destructive in Southern and North Central States, often reducing yields 20 percent or more. Rust pustules on oats were significantly smaller when plants were exposed to 10 parts per hundred million ozone for 6 hours in the light on the 10 days after infection. About half as many rust spores were produced in the ozone chamber as in one protected by carbon filters. Exposure to 10 pphm ozone did not affect viability of spores. Spores produced on exposed plants germinated and penetrated stomates of oat leaves as well as spores produced on unexposed leaves.

1970-01-01

394

Revealing source signatures in ambient BTEX concentrations  

International Nuclear Information System (INIS)

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

395

Revealing source signatures in ambient BTEX concentrations  

Energy Technology Data Exchange (ETDEWEB)

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration.

Zalel, Amir; Yuval [Environmental, Water and Agricultural Engineering Department, Faculty of Civil and Environmental Engineering, Israel Institute of Technology, T