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1

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1996-04-01

2

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1986-11-01

3

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-02-01

4

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-12-01

5

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)

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

2004-01-01

6

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

2008-04-18

7

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

International Nuclear Information System (INIS)

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

2005-01-01

8

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-11-15

9

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

International Nuclear Information System (INIS)

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

2008-01-01

10

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-10-15

11

Application of spectral coherence analysis to describe the relationships between ambient ozone exposure and crop growth.  

UK PubMed Central (United Kingdom)

Growth season-based time series spectral coherence analysis was performed between weekly changes in hourly ambient O(3) concentrations and weekly changes in alfalfa height growth. Weekly median hourly O(3) concentration and the corresponding weekly cumulative integral (sum of all hourly concentrations within the week) were used as indicators of weekly O(3) spectral density and coherence with the change in weekly alfalfa height growth. In general, the weekly cumulative integral performed much better than the weekly median O(3) concentration. A conceptual analysis of the results is presented, along with a recommendation that crop growth stage-based cumulative integrals merit further evaluation towards a better understanding of cause-effect relationships.

Krupa SV; Nosal M

1989-01-01

12

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...

13

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

UK PubMed Central (United Kingdom)

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).

Singh P; Agrawal M; Agrawal SB

2009-03-01

14

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

International Nuclear Information System (INIS)

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

2007-01-01

15

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

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

16

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

17

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)

2008-09-00

18

Ethylenediurea (EDU) affects the growth of ozone-sensitive and tolerant ash (Fraxinus excelsior) trees under ambient O3 conditions.  

UK PubMed Central (United Kingdom)

Adult ash trees (Fraxinus excelsior L.), known to be sensitive or tolerant to ozone, determined by presence or absence of foliar symptoms in previous years, were treated with ethylenediurea (EDU) at 450 ppm by gravitational trunk infusion over the 2005 growing season (32.5 ppm h AOT40). Tree and shoot growth were recorded in May and September. Leaf area, ectomycorrhizal infection, and leaf and fine root biomass were determined in September. EDU enhanced shoot length and diameter, and the number and area of leaves, in both O3-sensitive and tolerant trees. However, no EDU effects were recorded at the fine root and tree level. Therefore, a potential for EDU protection against O3-caused growth losses of forest trees should be evaluated during longer-term experiments.

Paoletti E; Contran N; Manning WJ; Tagliaferro F

2007-01-01

19

Ethylenediurea (EDU) affects the growth of ozone-sensitive and tolerant ash (Fraxinus excelsior) trees under ambient O3 conditions.  

Science.gov (United States)

Adult ash trees (Fraxinus excelsior L.), known to be sensitive or tolerant to ozone, determined by presence or absence of foliar symptoms in previous years, were treated with ethylenediurea (EDU) at 450 ppm by gravitational trunk infusion over the 2005 growing season (32.5 ppm h AOT40). Tree and shoot growth were recorded in May and September. Leaf area, ectomycorrhizal infection, and leaf and fine root biomass were determined in September. EDU enhanced shoot length and diameter, and the number and area of leaves, in both O3-sensitive and tolerant trees. However, no EDU effects were recorded at the fine root and tree level. Therefore, a potential for EDU protection against O3-caused growth losses of forest trees should be evaluated during longer-term experiments. PMID:17450289

Paoletti, Elena; Contran, Nicla; Manning, William J; Tagliaferro, Francesco

2007-03-21

20

Ambient ozone causes upper airways inflammation in children  

Energy Technology Data Exchange (ETDEWEB)

Ozone constitutes a major air pollutant in Western Europe. During the summer national air quality standards are frequently exceeded, which justifies concern about the health effects of ozone at ambient concentrations. We studied upper airways inflammation after ozone exposure in 44 children by repeated nasal lavages from May to October 1991 in Umkirch, Germany.

Frischer, T.M.; Kuehr, J.; Pullwitt, A.; Meinert, R.; Forster, J.

1993-01-01

 
 
 
 
21

Study of ambient ozone phytotoxicity in Ukraine and ozone protective effect of some antioxidants.  

UK PubMed Central (United Kingdom)

The aim of the study was to assess ambient ozone phytotoxicity in Kyiv (Ukraine) using bioindicator clover plants (Trifolium subterraneum cv. Geraldton) and to test some natural and synthetic antioxidants as ozone protectants. The results obtained showed that ambient ozone concentrations were high enough to cause visible leaf injury in clover. All used substances showed partial ozone protective effect on clover. Water extracts from the leaves of plants, known to contain flavonoids-antioxidants showed weaker ozone protective effect and were less stable in the field conditions than synthetic antioxidants. Among the studied extracts, those from Ocimum basilicum and Tagetes patula were more effective as ozone protectants than the one from Salvia sclarea.

Blum O; Didyk N

2007-11-01

22

Evidence for impacts of near-ambient ozone concentrations on vegetation in southern Sweden.  

Science.gov (United States)

Substantial impacts of near-ambient ozone concentrations on agricultural crops, trees, and seminatural vegetation are demonstrated for southern Sweden. Impacts of ambient ozone levels (2-15 microL L(-1) hr annual accumulated ozone exposure over a threshold of 40 nL L(-1) [AOT40]) range from a 2%-10% reduction for trees (e.g., leaf chlorophyll, tree growth) up to a 15% reduction for crops (e.g., yield, wheat/potato). Visible leaf injury on bioindicator plants caused by ambient ozone levels has been clearly demonstrated. The humid climatic conditions in Sweden promote high rates of leaf ozone uptake at a certain ozone concentration. This likely explains the comparatively large ozone impacts found for vegetation in southern Sweden at relatively low ozone concentrations in the air. It is important that the future methods used for the representation of ozone impacts on vegetation across Europe are based on the leaf ozone uptake concept and not on concentration-based exposure indices, such as AOT40. PMID:20175441

Karlsson, Per Erik; Pleijel, Håkan; Danielsson, Helena; Karlsson, Gunilla Pihl; Piikki, Kristin; Uddling, Johan

2009-12-01

23

Evidence for impacts of near-ambient ozone concentrations on vegetation in southern Sweden.  

UK PubMed Central (United Kingdom)

Substantial impacts of near-ambient ozone concentrations on agricultural crops, trees, and seminatural vegetation are demonstrated for southern Sweden. Impacts of ambient ozone levels (2-15 microL L(-1) hr annual accumulated ozone exposure over a threshold of 40 nL L(-1) [AOT40]) range from a 2%-10% reduction for trees (e.g., leaf chlorophyll, tree growth) up to a 15% reduction for crops (e.g., yield, wheat/potato). Visible leaf injury on bioindicator plants caused by ambient ozone levels has been clearly demonstrated. The humid climatic conditions in Sweden promote high rates of leaf ozone uptake at a certain ozone concentration. This likely explains the comparatively large ozone impacts found for vegetation in southern Sweden at relatively low ozone concentrations in the air. It is important that the future methods used for the representation of ozone impacts on vegetation across Europe are based on the leaf ozone uptake concept and not on concentration-based exposure indices, such as AOT40.

Karlsson PE; Pleijel H; Danielsson H; Karlsson GP; Piikki K; Uddling J

2009-12-01

24

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 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.

2012-01-01

25

Study of ambient ozone phytotoxicity in Ukraine and ozone protective effect of some antioxidants.  

Science.gov (United States)

The aim of the study was to assess ambient ozone phytotoxicity in Kyiv (Ukraine) using bioindicator clover plants (Trifolium subterraneum cv. Geraldton) and to test some natural and synthetic antioxidants as ozone protectants. The results obtained showed that ambient ozone concentrations were high enough to cause visible leaf injury in clover. All used substances showed partial ozone protective effect on clover. Water extracts from the leaves of plants, known to contain flavonoids-antioxidants showed weaker ozone protective effect and were less stable in the field conditions than synthetic antioxidants. Among the studied extracts, those from Ocimum basilicum and Tagetes patula were more effective as ozone protectants than the one from Salvia sclarea. PMID:17703879

Blum, Oleg; Didyk, Nataliya

2007-07-05

26

The Impact of Sulfur Dioxide on a Processing Tomato Stressed with Chronic Ambient Ozone.  

Science.gov (United States)

This study was designed to identify growth and yield responses of VF 145B-7879 processing tomato plants from ambient ozone and varying SO2 exposures. The definition of possible interactions between the two gases was of greatest interest. A 3 x 3 factorial...

R. J. Oshima

1979-01-01

27

Measuring the penetration of ambient ozone into residential buildings.  

UK PubMed Central (United Kingdom)

Much of human exposure to ambient ozone and ozone reaction byproducts occurs inside buildings. However, there are currently no experimental data on the ability of ozone to penetrate through building envelopes and into residences. This paper presents a method to determine the penetration factor for ozone in buildings, and applies it in an unoccupied test house and seven single-family residences. The mean (±SD) ozone penetration factor was measured as 0.79 ± 0.13 in the eight homes using this method, ranging from 0.62 ± 0.09 to 1.02 ± 0.15. An analysis of tests across the homes revealed that ozone penetration was significantly higher in homes with more painted wood envelope materials, homes with larger air leakage exponents from fan pressurization tests, and older homes. The test method utilizes a large calibrated fan to elevate air exchange rates and steady-state indoor ozone concentrations to levels that can be accurately measured, so there is a potential for overpredicting ozone penetration factors. However, evidence suggests that this bias is likely small in most of the homes, and, even if a bias exists, the measured ozone penetration factors were lower than the usual assumption of unity in seven of the eight tested homes.

Stephens B; Gall ET; Siegel JA

2012-01-01

28

Bioindicator plants for ambient ozone in Central and Eastern Europe  

International Nuclear Information System (INIS)

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

2004-01-01

29

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

2013-06-24

30

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-10-15

31

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.

2010-01-01

32

Variations in the ambient ozone concentration during the 26 February 1979 solar eclipse  

Energy Technology Data Exchange (ETDEWEB)

The ambient ozone concentration was measured during the partial solar eclipse on 26 February 1979, at Argonne National Laboratory. A 50% reduction in the ozone concentration occurred during the eclipse as a result of photochemical reactions. The observed lag time between the minima of the solar radiation and the ozone concentration is consistent with the computed lag time. The labile nature of ozone is self-evident in what may be the first measurement of the ambient ozone concentration during a solar eclipse.

Eastman, J.A. (Argonne National Lab., IL); Stedman, D.H.

1980-01-01

33

Growth-stage dependent crop yield response to ozone exposure.  

UK PubMed Central (United Kingdom)

Data from four crop yield-loss field trials were examined to determine if analysis using an imposed phenological weighting function based on seasonal growth stage would provide a more accurate indication of impact of ozone exposure. Alfalfa (Medicago sativa L. cv. Moapa 69), dry bean (Phaseolus vulgaris L. cv. California Dark Red kidney), fresh market and processing tomato (Lycopersicon esculentum Mill. cv. 6718 VF and VF-145-B7879, respectively) were grown at 9-11 ambient field plots within southern California comprising an ambient gradient of ozone. The growing season for each crop was artificially divided into 'quarters' composed of equal numbers of whole days and roughly corresponding to specific growth stages. Ozone exposure was calculated for each of these 'quarters' and regressed against final crop yield using 163 different exposure statistics. Weighting functions were developed using reciprocal residual mean square (1/RMS) or percentage of the best 100 exposure statistics of the 163 tested (TOP100) for each of the quarters. The third quarter of the alfalfa season was clearly most responsive to ozone as measured by both of the weighting functions. Third quarter ozone was also weighted highest by both weighting functions for dry bean. Fresh market and processing tomato were each influenced the greatest by second quartero zone as demonstrated by both weighting functions. The occurrence of ozone during physiologically important events (flowering and initial fruit set in second quarter for tomato; pod development in third quarter for dry bean) appeared to influence the yield of these crops the greatest. Growth-stage-dependent phenological weighting of pollutant exposure may result in more effective predictions of levels of ozone exposure resulting in yield reductions.

Younglove T; McCool PM; Musselman RC; Kahl ME

1994-01-01

34

Growth-stage dependent crop yield response to ozone exposure.  

Science.gov (United States)

Data from four crop yield-loss field trials were examined to determine if analysis using an imposed phenological weighting function based on seasonal growth stage would provide a more accurate indication of impact of ozone exposure. Alfalfa (Medicago sativa L. cv. Moapa 69), dry bean (Phaseolus vulgaris L. cv. California Dark Red kidney), fresh market and processing tomato (Lycopersicon esculentum Mill. cv. 6718 VF and VF-145-B7879, respectively) were grown at 9-11 ambient field plots within southern California comprising an ambient gradient of ozone. The growing season for each crop was artificially divided into 'quarters' composed of equal numbers of whole days and roughly corresponding to specific growth stages. Ozone exposure was calculated for each of these 'quarters' and regressed against final crop yield using 163 different exposure statistics. Weighting functions were developed using reciprocal residual mean square (1/RMS) or percentage of the best 100 exposure statistics of the 163 tested (TOP100) for each of the quarters. The third quarter of the alfalfa season was clearly most responsive to ozone as measured by both of the weighting functions. Third quarter ozone was also weighted highest by both weighting functions for dry bean. Fresh market and processing tomato were each influenced the greatest by second quartero zone as demonstrated by both weighting functions. The occurrence of ozone during physiologically important events (flowering and initial fruit set in second quarter for tomato; pod development in third quarter for dry bean) appeared to influence the yield of these crops the greatest. Growth-stage-dependent phenological weighting of pollutant exposure may result in more effective predictions of levels of ozone exposure resulting in yield reductions. PMID:15091620

Younglove, T; McCool, P M; Musselman, R C; Kahl, M E

1994-01-01

35

Compact automated ozone monitor for ambient air quality applications  

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-07-01

36

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; Eugeniusz Porada; Gilaad G. Kaplan; Brian H. Rowe

2010-01-01

37

Detecting plant effects is necessary to give biological significance to ambient ozone monitoring data and predictive ozone standards  

Energy Technology Data Exchange (ETDEWEB)

The use of mechanical monitors and passive samplers has made it possible to assess concentrations of ozone over wide areas and to develop air quality standards, like AOT40 and SUM60. Monitored ozone data and AOT40 and SUM60 are also used to predict ozone injury on local and regional scales. The data and the standards do not include or account for environmental and biological variables that affect ozone uptake and plant injury. Ground proofing via vegetation surveys must be done to verify and validate plant injury predictions. If this is not done, then the standards have no biological significance and are only exercises in air quality assessment. - Ambient ozone monitoring data and predictive ozone standards cannot be used to accurately predict plant ozone injury.

Manning, William J

2003-12-01

38

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1987-12-01

39

Association between ambient ozone and health outcomes in Prague.  

UK PubMed Central (United Kingdom)

PURPOSE: Though numerous studies investigating ambient ozone (O(3)) effects on human health were published, such a study for Central Europe is still lacking. We have investigated the association between ozone (O(3)) levels and hospital admissions and mortality due to cardiovascular and respiratory diseases for Prague inhabitants for summer months (April-September) over the 5-year period 2002-2006. Our hypothesis was that ambient O(3) levels in Prague resulted in adverse health outcomes and were associated with increased mortality and hospital admissions. METHODS: The effect of O(3) on mortality and hospital admissions was investigated using the negative binomial regression after controlling for the influence of meteorological factors (air temperature and relative humidity) and calendar effects (seasonal patterns, long-term trends and day of week). RESULTS: We found a statistically significant association between O(3) levels and daily mortality from respiratory diseases. Relative risk of 1.080 (95% CI: 1.031-1.132) was observed for mortality from respiratory diseases per 10 ?g m(-3) increase in 1-day lagged daily mean O(3) concentration. No statistically significant association was detected between O(3) concentrations and daily mortality from all causes, daily mortality from cardiovascular diseases and hospital admissions for respiratory and cardiovascular diseases. The O(3) effects differed in men and women, nevertheless, the results were ambiguous with respect to used lag and O(3) metrics. No significant confounding effects of PM(10) on the investigated association were observed. CONCLUSIONS: O(3) exposure in Prague, though lower as compared to many other cities in Europe, is high enough to cause adverse health effects.

H?nová I; Malý M; ?ezá?ová J; Braniš M

2013-01-01

40

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

UK PubMed Central (United Kingdom)

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, 5 days/wk, for a total of 57 days during July, August, and September. Ripe fruit yields were decreased 16% by O3 in NF compared with CF air. The highest dose of SO2 given in CF air reduced fruit yield by 18%. Ambient O3 and the SO2 treatments were additive in their effects on fruit yields. Significant reductions in fruit numbers were observed. Fruit quality was not measurably altered. A negative linear response for ripe fruit yield vs. SO2 exposure dose was demonstrated. As the SO2 dose was increased, sulfur (S) content of the leaves increased linearly. In NF air, S content ranged from 1.62 to 2.56%. In both CF and NF air, S content of fruits was 0.24%; and, the SO2 treatments did not cause measurable changes. Foliar concentrations of other elements were changed significantly by leaf position and harvest date, but not by SO2 treatments.

Heggestad HE; Bennett JH; Lee EH; Douglass LW

1986-12-01

 
 
 
 
41

Field testing of new-technology ambient air ozone monitors.  

Science.gov (United States)

Multibillion-dollar strategies control ambient air ozone (O3) levels in the United States, so it is essential that the measurements made to assess compliance with regulations be accurate. The predominant method employed to monitor O3 is ultraviolet (UV) photometry. Instruments employ a selective manganese dioxide or heated silver wool "scrubber" to remove O3 to provide a zero reference signal. Unfortunately, such scrubbers remove atmospheric constituents that absorb 254-nm light, causing measurement interference. Water vapor also interferes with the measurement under some circumstances. We report results of a 3-month field test of two new instruments designed to minimize interferences (2B Technologies model 211; Teledyne-API model 265E) that were operated in parallel with a conventional Thermo Scientific model 49C O3 monitor. The field test was hosted by the Houston Regional Monitoring Corporation (HRM). The model 211 photometer scrubs O3 with excess nitric oxide (NO) generated in situ by photolysis of added nitrous oxide (N2O) to provide a reference signal, eliminating the need for a conventional O3 scrubber. The model 265E analyzer directly measures O3-NO chemiluminescence from added excess NO to quantify O3 in the sample stream. Extensive quality control (QC) and collocated monitoring data are assessed to evaluate potential improvements to the accuracy of O3 compliance monitoring. Implications: Two new-technology ozone monitors were compared with a conventional monitor under field conditions. Over 3 months the conventional monitor reported more exceedances of the current standard than the new instruments, which could potentially result in an area being misjudged as "nonattainment." Instrument drift can affect O3 data accuracy, and the same degree of drift has a proportionally greater compliance effect as standard stringency is increased. Enhanced data quality assurance and data adjustment may be necessary to achieve the improved accuracy required to judge compliance with tighter standards. PMID:23926854

Ollison, Will M; Crow, Walt; Spicer, Chester W

2013-07-01

42

Field testing of new-technology ambient air ozone monitors.  

UK PubMed Central (United Kingdom)

Multibillion-dollar strategies control ambient air ozone (O3) levels in the United States, so it is essential that the measurements made to assess compliance with regulations be accurate. The predominant method employed to monitor O3 is ultraviolet (UV) photometry. Instruments employ a selective manganese dioxide or heated silver wool "scrubber" to remove O3 to provide a zero reference signal. Unfortunately, such scrubbers remove atmospheric constituents that absorb 254-nm light, causing measurement interference. Water vapor also interferes with the measurement under some circumstances. We report results of a 3-month field test of two new instruments designed to minimize interferences (2B Technologies model 211; Teledyne-API model 265E) that were operated in parallel with a conventional Thermo Scientific model 49C O3 monitor. The field test was hosted by the Houston Regional Monitoring Corporation (HRM). The model 211 photometer scrubs O3 with excess nitric oxide (NO) generated in situ by photolysis of added nitrous oxide (N2O) to provide a reference signal, eliminating the need for a conventional O3 scrubber. The model 265E analyzer directly measures O3-NO chemiluminescence from added excess NO to quantify O3 in the sample stream. Extensive quality control (QC) and collocated monitoring data are assessed to evaluate potential improvements to the accuracy of O3 compliance monitoring. Implications: Two new-technology ozone monitors were compared with a conventional monitor under field conditions. Over 3 months the conventional monitor reported more exceedances of the current standard than the new instruments, which could potentially result in an area being misjudged as "nonattainment." Instrument drift can affect O3 data accuracy, and the same degree of drift has a proportionally greater compliance effect as standard stringency is increased. Enhanced data quality assurance and data adjustment may be necessary to achieve the improved accuracy required to judge compliance with tighter standards.

Ollison WM; Crow W; Spicer CW

2013-07-01

43

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

44

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

Science.gov (United States)

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

45

Meta-analysis of the Chinese studies of the association between ambient ozone and mortality.  

UK PubMed Central (United Kingdom)

To investigate short-term effects of ambient ozone exposure on mortality in Chinese cities, we conducted a meta-analysis of 10 effect estimates of 5 short-term studies, which reported associations between ambient ozone and mortality in Chinese mainland cities. And we estimated pooled effects by non-accidental mortality, cardiovascular mortality, and respiratory mortality. Combined estimates and their 95%CI were tested by RevMan 5, and Funnel plots were used for the bias analysis. For a 10?gm(-3) increase of maximum 8-h average concentration of ozone, the percent change for non-accidental mortality, cardiovascular mortality, and respiratory mortality were 0.42 (95%CI, 0.32-0.52%), 0.44% (95%CI, 0.17-0.70%) and 0.50% (95%CI, 0.22-0.77%), respectively. Compared with pooled estimates from other meta-analyses on ambient ozone-associated mortality, our pooled estimate for non-accidental mortality was slightly higher than previous ones and pooled estimate for cardiovascular mortality was consistent with others. However, we observed significantly positive association between ambient ozone and respiratory mortality, which were generally nonsignificant in earlier studies. By combining estimates from published evidence, a small but substantial association between ambient ozone level and mortality was observed in Mainland China.

Yan M; Liu Z; Liu X; Duan H; Li T

2013-06-01

46

Assessment of ambient ozone air quality and evidence of transport effects in eastern Kern County, California  

Energy Technology Data Exchange (ETDEWEB)

Edwards AFB is located in the Mojave desert of southern California. The bulk of the base is located in the eastern part of Kern County, and is classified as serious non-attainment for ozone. However, geographically the eastern part of Kern County is separated form the western part of the county by some of the tallest mountains in the continental US. It has long been suspected, but not well quantified, that the air quality in eastern Kern County is impacted by transport of ozone from the San Joaquin area (as well as possible transport from the Los Angeles Basin area). Because of the significance of the ozone non-attainment designation with regards to the Department of Defense Base Realignment and Closure process, improved assessment of ambient ozone air quality and possible routes of transport in eastern Kern County was required. This was accomplished by; installing and operating an ambient air quality monitoring station at Edwards AFB; and comparing at least one year of data (ozone, NO{sub x} and meteorological) from the Edwards AFB station with similar data from the California Air Resources Board operated stations in the upwind locations (along possible transport routes) of Edison (western Kern County), Mojave (eastern Kern County) and Lancaster (northern Los Angeles County). Empirical analysis of this and other data indicate that; (1) compared to western Kern County, eastern Kern County is in a significantly different and isolated air basin; (2) the peak ambient ozone levels in eastern Kern County are substantially lower than in western Kern County; (3) peak ambient ozone levels in eastern Kern County occur late afternoon/early evening and are indicative of transport of ozone and (4) direct transport of ozone from the San Joaquin and/or South Coast area does occur (given proper conditions). This paper will address the elements of this study and its conclusions.

Beutelman, H.P. [Tybrin Corp., Edwards AFB, CA (United States); Hallman, P.K.; Franz, J.A. [USAF/AFFTC/EM, Edwards AFB, CA (United States); Moritsch, M.Q. [Computer Sciences Corp., Edwards AFB, CA (United States)

1998-12-31

47

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...

48

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

International Nuclear Information System (INIS)

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

2008-03-10

49

75 FR 2938 - National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...aggravation of asthma), decreased pulmonary defense mechanisms (suggestive...infection), and indicators of pulmonary inflammation (related to...heart failure, arrhythmia, embolism, thrombosis, and other...Environmental ozone field study on pulmonary and subjective...

2010-01-19

50

Factors influencing the reactivity of polycyclic aromatic hydrocarbons absorbed on filters and ambient POM with ozone  

Energy Technology Data Exchange (ETDEWEB)

Five polycyclic aromatic hydrocarbons (PAH), pyrene (PY), fluoranthene (FL), benz(a)anthracene (BaA), benzo(a)pyrene (BaP), and benzo(e)pyrene (BeP) absorbed on glass fiber (GF) and Teflon impregnated glass fiber TIGF) filters and on ambient particulate organic matter (POM) were exposed to ozone (50-300 ppb) passively in a 360-liter Teflon chamber and actively in a flow system. The influence of ozone concentration, exposure time and relative humidity (RH) on the degree of degradation of these PAH was established. The most reactive PAH both on filters and in ambient POM were PY, BaA and BaP. Up to 50-80% of these PAH degraded in 3-hr exposures to 200 ppb of ozone at approx.1% RH: in a flow system, most of the degradation occurred within the first 10 minutes of exposure. With the exception of BaP, the degradation of the PAH tested on GF and TIGF filters were much lower at 50% RH than at 1% RH, whether they were exposed to ozone in an active or passive mode. Interestingly, RH did not significantly affect the reactivity of PAH present in ambient POM passively exposed to ozone. The results show that PAH are susceptible to ozone degradation under many typical atmospheric conditions.

Pitts, J.N. Jr.; Paur, H.R.; Zielinska, B.; Arey, J.; Winer, A.M.; Ramdahl, T.; Mejia, V.

1986-01-01

51

Colorimetric determination of ambient ozone using indigo blue droplet  

Directory of Open Access Journals (Sweden)

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

Felix Erika P.; Cardoso Arnaldo A.

2006-01-01

52

Colorimetric determination of ambient ozone using indigo blue droplet  

Scientific Electronic Library Online (English)

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

Felix, Erika P.; Cardoso, Arnaldo A.

2006-04-01

53

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

Science.gov (United States)

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

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

2007-07-01

54

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

International Nuclear Information System (INIS)

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

2010-01-01

55

Near-ambient ozone concentrations reduce the vigor of Betula and Populus species in Finland.  

UK PubMed Central (United Kingdom)

In this review the main growth responses of Finnish birch (Betula pendula, B. pubescens) and aspen species (Populus tremula and P. tremuloides x P. tremula) are correlated with ozone exposure, indicated as the AOT40 value. Data are derived from 23 different laboratory, open-top chamber, and free-air fumigation experiments. Our results indicate that these tree species are sensitive to increasing ozone concentrations, though high intraspecific variation exists. The roots are the most vulnerable targets in both genera. These growth reductions, determined from trees grown under optimal nutrient and water supply, were generally accompanied by increased visible foliar injuries, carbon allocation toward defensive compounds, reduced carbohydrate contents of leaves, impaired photosynthesis processes, disturbances in stomatal function, and earlier autumn senescence. Because both genera have shown complex ozone defense and response mechanisms, which are modified by variable environmental conditions, a mechanistically based approach is necessary for accurate ozone risk assessment.

Oksanen E; Manninen S; Vapaavuori E; Holopainen T

2009-12-01

56

Near-ambient ozone concentrations reduce the vigor of Betula and Populus species in Finland.  

Science.gov (United States)

In this review the main growth responses of Finnish birch (Betula pendula, B. pubescens) and aspen species (Populus tremula and P. tremuloides x P. tremula) are correlated with ozone exposure, indicated as the AOT40 value. Data are derived from 23 different laboratory, open-top chamber, and free-air fumigation experiments. Our results indicate that these tree species are sensitive to increasing ozone concentrations, though high intraspecific variation exists. The roots are the most vulnerable targets in both genera. These growth reductions, determined from trees grown under optimal nutrient and water supply, were generally accompanied by increased visible foliar injuries, carbon allocation toward defensive compounds, reduced carbohydrate contents of leaves, impaired photosynthesis processes, disturbances in stomatal function, and earlier autumn senescence. Because both genera have shown complex ozone defense and response mechanisms, which are modified by variable environmental conditions, a mechanistically based approach is necessary for accurate ozone risk assessment. PMID:20175439

Oksanen, Elina; Manninen, Sirkku; Vapaavuori, Elina; Holopainen, Toini

2009-12-01

57

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

UK PubMed Central (United Kingdom)

High ozone (O 3) concentrations not only damage plant life but also cause considerable losses in plant productivity. To screen for molecular factors usable as potential biomarkers to identify for O 3-sensitive and -tolerant lines and design O 3 tolerant crops, our project examines the effects of O 3 on rice, using high-throughput omics approaches. In this study, we examined growth and yield parameters of 4 rice cultivars fumigated for a life-time with ambient air (mean O 3: 31.4-32.7 ppb) or filtered air (mean O 3: 6.6-8.3 ppb) in small open-top chambers (sOTCs) to select O 3-sensitive (indica cv Takanari) and O 3-tolerant (japonica cv Koshihikari) cultivars for analysis of seed transcriptomes using Agilent 4 × 44K rice oligo DNA chip. Total RNA from dry mature dehusked seeds of Takanari and Koshihikari cultivars was extracted using a modified protocol based on cethyltrimethylammonium bromide extraction buffer and phenol-chloroform-isoamylalcohol treatment, followed by DNA microarray analysis using the established dye-swap method. Direct comparison of Koshihikari and Takanari O 3 transcriptomes in seeds of rice plants fumigated with ambient O 3 in sOTCs successfully showed that genes encoding proteins involved in jasmonic acid, GABA biosynthesis, cell wall and membrane modification, starch mobilization, and secondary metabolite biosynthesis are differently regulated in sensitive cv Takanari and tolerant cv Koshihikari. MapMan analysis further mapped the molecular factors activated by O 3, confirming Takanari is rightly classified as an O 3 sensitive genotype.

Cho K; Shibato J; Kubo A; Kohno Y; Satoh K; Kikuchi S; Sarkar A; Agrawal GK; Rakwal R

2013-09-01

58

Cotton yield losses and ambient ozone concentrations in California's San Joaquin Valley  

Energy Technology Data Exchange (ETDEWEB)

Based on controlled experiments and simulation modeling, ozone air pollution has been estimated to cause significant yield losses to cotton. The study reported here was conducted to verify losses for Acala cotton (Gossypium hirsutum SJ2) along a gradient of ambient ozone (O3) concentrations across the San Joaquin Valley in California. Cotton was grown in nonfiltered (NF) and charcoal-filtered (CF) open-top chambers at four sites during the 1988-1989 summer growing seasons. Cotton yields were reduced in NF compared to CF air in general proportion to O3 concentrations across all sites and years. Greatest cotton yield losses were at Dinuba on the east side of the San Joaquin Valley and lowest were on the west side of the valley. Ozone injury symptoms on cotton were most noticeable in areas with greatest yield losses.

Olszyk, D.; Bytnerowicz, A.; Kats, G.; Reagan, C.; Hake, S.

1993-01-01

59

A Direct Sensitivity Approach to Predict Hourly Ozone Resulting from Compliance with the National Ambient Air Quality Standard.  

UK PubMed Central (United Kingdom)

In setting primary ambient air quality standards, the EPA's responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and risks associated with ambient ozone pollution using a statistical approach to adjust recent air quality to simulate just meeting the current standard level, without specifying emission control strategies. One drawback of this purely statistical concentration rollback approach is that it does not take into account spatial and temporal heterogeneity of ozone response to emissions changes. The application of the higher-order decoupled direct method (HDDM) in the community multiscale air quality (CMAQ) model is discussed here to provide an example of a methodology that could incorporate this variability into the risk assessment analyses. Because this approach includes a full representation of the chemical production and physical transport of ozone in the atmosphere, it does not require assumed background concentrations, which have been applied to constrain estimates from past statistical techniques. The CMAQ-HDDM adjustment approach is extended to measured ozone concentrations by determining typical sensitivities at each monitor location and hour of the day based on a linear relationship between first-order sensitivities and hourly ozone values. This approach is demonstrated by modeling ozone responses for monitor locations in Detroit and Charlotte to domain-wide reductions in anthropogenic NOx and VOCs emissions. As seen in previous studies, ozone response calculated using HDDM compared well to brute-force emissions changes up to approximately a 50% reduction in emissions. A new stepwise approach is developed here to apply this method to emissions reductions beyond 50% allowing for the simulation of more stringent reductions in ozone concentrations. Compared to previous rollback methods, this application of modeled sensitivities to ambient ozone concentrations provides a more realistic spatial response of ozone concentrations at monitors inside and outside the urban core and at hours of both high and low ozone concentrations.

Simon H; Baker KR; Akhtar F; Napelenok SL; Possiel N; Wells B; Timin B

2013-02-01

60

Constraining ozone-precursor responsiveness using ambient measurements  

Science.gov (United States)

This study develops probabilistic estimates of ozone (O3) sensitivities to precursor emissions by incorporating uncertainties in photochemical modeling and evaluating model performance based on ground-level observations of O3 and oxides of nitrogen (NOx). Uncertainties in model formulations and input parameters are jointly considered to identify factors that strongly influence O3 concentrations and sensitivities in the Dallas-Fort Worth region in Texas. Weightings based on a Bayesian inference technique and screenings based on model performance and statistical tests of significance are used to generate probabilistic representation of O3 response to emissions and model input parameters. Adjusted (observation-constrained) results favor simulations using the sixth version of the carbon bond chemical mechanism (CB6) and scaled-up emissions of NOx, dampening the overall sensitivity of O3 to NOx and increasing the sensitivity of O3 to volatile organic compounds in the study region. This approach of using observations to adjust and constrain model simulations can provide probabilistic representations of pollutant responsiveness to emission controls that complement the results obtained from deterministic air-quality modeling.

Digar, Antara; Cohan, Daniel S.; Xiao, Xue; Foley, Kristen M.; Koo, Bonyoung; Yarwood, Greg

2013-01-01

 
 
 
 
61

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

62

Root growth and physiology of potted and field-grown trembling aspen exposed to tropospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

Root growth and respiration of potted plants and field-grown trembling aspen trees exposed to ambient and twice ambient ozone concentrations were studied. Results showed a decrease of 45 per cent in root dry weight after 12 weeks of ozone treatment, and a decrease in root respiration of 27 per cent. In the case of potted plants the ozone-induced decrease in root system respiration was believed to be more closely correlated with decreased root dry weight than with specific root respiration. Length of live roots in field-grown trees was found to increase rapidly early in the season, peaking by mid-season, combined with a decrease in root production and increase in root disappearance in late season. CO{sub 2} efflux of field-grown trees decreased significantly with ozone treatment, however, without further evidence it is not possible to state that CO{sub 2} efflux is directly attributable to decreased root growth. 54 refs., 7 figs.

Coleman, M. D.; Dickson, R. E.; Isebrands, J. G. [Forest Service, Rhinelander, WI (United States). North Central Forest Experiment Station; Karnosky, D. F. [Michigan Technological Univ., Houghton, MI (United States). School of Forestry and Wood Products

1996-01-01

63

Opposing effects of particle pollution, ozone, and ambient temperature on arterial blood pressure.  

UK PubMed Central (United Kingdom)

BACKGROUND: Diabetes increases the risk of hypertension and orthostatic hypotension and raises the risk of cardiovascular death during heat waves and high pollution episodes. OBJECTIVE: We examined whether short-term exposures to air pollution (fine particles, ozone) and heat resulted in perturbation of arterial blood pressure (BP) in persons with type 2 diabetes mellitus (T2DM). METHODS: We conducted a panel study in 70 subjects with T2DM, measuring BP by automated oscillometric sphygmomanometer and pulse wave analysis every 2 weeks on up to five occasions (355 repeated measures). Hourly central site measurements of fine particles, ozone, and meteorology were conducted. We applied linear mixed models with random participant intercepts to investigate the association of fine particles, ozone, and ambient temperature with systolic, diastolic, and mean arterial BP in a multipollutant model, controlling for season, meteorological variables, and subject characteristics. RESULTS: An interquartile increase in ambient fine particle mass [particulate matter (PM) with an aerodynamic diameter of ? 2.5 ?m (PM2.5)] and in the traffic component black carbon in the previous 5 days (3.54 and 0.25 ?g/m3, respectively) predicted increases of 1.4 mmHg [95% confidence interval (CI): 0.0, 2.9 mmHg] and 2.2 mmHg (95% CI: 0.4, 4.0 mmHg) in systolic BP (SBP) at the population geometric mean, respectively. In contrast, an interquartile increase in the 5-day mean of ozone (13.3 ppb) was associated with a 5.2 mmHg (95% CI: -8.6, -1.8 mmHg) decrease in SBP. Higher temperatures were associated with a marginal decrease in BP. CONCLUSIONS: In subjects with T2DM, PM was associated with increased BP, and ozone was associated with decreased BP. These effects may be clinically important in patients with already compromised autoregulatory function.

Hoffmann B; Luttmann-Gibson H; Cohen A; Zanobetti A; de Souza C; Foley C; Suh HH; Coull BA; Schwartz J; Mittleman M; Stone P; Horton E; Gold DR

2012-02-01

64

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

Energy Technology Data Exchange (ETDEWEB)

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

Cooley, D.R.

1986-01-01

65

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

International Nuclear Information System (INIS)

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

2006-01-01

66

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

Energy Technology Data Exchange (ETDEWEB)

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

Mazarura, U.

1997-12-31

67

Cotton yield losses and ambient ozone concentrations in California`s San Joaquin Valley  

Energy Technology Data Exchange (ETDEWEB)

Based on controlled experiments and simulation modeling, ozone (O{sub 3}) has been estimated to cause significant yield losses to cotton. The study reported here was conducted to verity losses for {open_quote}Acala{close_quote} cotton along a gradient of ambient O{sub 3} concentrations across the San Joaquin Valley in California. Cotton was grown in nonfiltered (NF) and charcoal-filtered (CF) open-top chambers, and ambient air (AA) at four sites during the 1988 and 1989 summer growing seasons. Cotton yields (weights of mature bolls m{sup -2}) were reduced in NF compared with CF air in general proportion to O{sub 3} concentrations across all sites and years. Greatest cotton yield losses were as Shafter in the southern part of the San Joaquin Valley (20% in 1989), and lowest losses were at Five Points in the western part of the valley (none in 1989). Ozone injury symptoms on cotton were most noticeable in areas with greatest yield losses. Linear O{sub 3} exposure vs. predicted relative yield loss models using four common exposure indices were constructed for each site and year based on the NF, CF, and AA data. All models except the second highest daily maximum concentration (2ndHDM, the current ambient air quality standard for O{sub 3}) predicted yield losses comparable to those predicted with previously published models for cotton in the San Joaquin Valley. Ozone exposure indices giving more weight to higher O{sub 3} concentrations or the 7-h daytime mean better predicted cotton yield responses over the growing season than 2ndHDM. 27 refs., 2 figs., 7 tabs.

Olszyk, D. [Pacific Southwest Lab., Riverside, CA (United States); Kats, G.; Reagan, C. [Univ. of California, Riverside, CA (United States)] [and others

1993-07-01

68

Relation of peak expiratory flow rates and symptoms to ambient ozone.  

UK PubMed Central (United Kingdom)

The temporal association between peak expiratory flow rates (PEFRs) and ambient ozone (O3) was studied in a group of 287 children and 523 nonsmoking adults in Tucson. In children, noon PEFRs were decreased on days when there was a higher O3 concentration; children with physician-confirmed asthma experienced the greatest decrease in noon PEFR. Evening PEFR levels were also significantly related to O3 in children, especially asthmatics. Among adults, evening PEFRs were decreased in asthmatics who spent more time outdoors on days when O3 levels were higher. After we adjusted for covariates, significant effects of interactions of 8-h O3 levels with particulate matter (PM10) and temperature on daily PEFR were found. There was some overnight effect of 8-h O3 on morning PEFRs. In general, the respiratory response to low-level ambient O3 is acute, occurs more in asthmatics, and increases as temperature and PM10 increase.

Krzyzanowski M; Quackenboss JJ; Lebowitz MD

1992-03-01

69

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.

2010-01-01

70

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. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November and 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. Roy; G. Beig; S. Ghude

2009-01-01

71

Intraspecific responses of six Indian clover cultivars under ambient and elevated levels of ozone.  

UK PubMed Central (United Kingdom)

Intraspecific variation in six cultivars of clover Trifolium alexandrinum L., (Bundel, Wardan, JHB-146, Saidi, Fahli, and Mescavi) has been studied with ambient and elevated O3 (ambient?+?10 ppb O3) in open top chambers. Significant effect of elevated O3 was detected on different morphological, physiological, and biochemical parameters depicting differential response among the test cultivars. Results showed that the magnitude of O3 induced foliar injury symptoms varied in all the cultivars. Ozone significantly depressed photosynthetic rate, stomatal conductance, and photosynthetic efficiency, although variations were cultivar specific. Ozone treatment diminished total biomass of all the cultivars; reduction was highest in Wardan with least O3 resistance followed by Bundel, JHB-146, Saidi, Mescavi, and Fahli. According to the cumulative sensitive index, variations in the sensitivity showed that two cultivars (Wardan and Bundel) were sensitive to elevated O3, while other three cultivars (Fahli, Saidi, and Mescavi) were resistant, and JHB-146 showed intermediate sensitivity. Therefore, the present study supported the selection of sensitive cultivar of clover as a bioindicator for O3 under Indian conditions for the areas experiencing higher concentrations of O3.

Chaudhary N; Agrawal SB

2013-08-01

72

Intraspecific responses of six Indian clover cultivars under ambient and elevated levels of ozone.  

Science.gov (United States)

Intraspecific variation in six cultivars of clover Trifolium alexandrinum L., (Bundel, Wardan, JHB-146, Saidi, Fahli, and Mescavi) has been studied with ambient and elevated O3 (ambient?+?10 ppb O3) in open top chambers. Significant effect of elevated O3 was detected on different morphological, physiological, and biochemical parameters depicting differential response among the test cultivars. Results showed that the magnitude of O3 induced foliar injury symptoms varied in all the cultivars. Ozone significantly depressed photosynthetic rate, stomatal conductance, and photosynthetic efficiency, although variations were cultivar specific. Ozone treatment diminished total biomass of all the cultivars; reduction was highest in Wardan with least O3 resistance followed by Bundel, JHB-146, Saidi, Mescavi, and Fahli. According to the cumulative sensitive index, variations in the sensitivity showed that two cultivars (Wardan and Bundel) were sensitive to elevated O3, while other three cultivars (Fahli, Saidi, and Mescavi) were resistant, and JHB-146 showed intermediate sensitivity. Therefore, the present study supported the selection of sensitive cultivar of clover as a bioindicator for O3 under Indian conditions for the areas experiencing higher concentrations of O3. PMID:23389856

Chaudhary, Nivedita; Agrawal, S B

2013-02-07

73

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

Science.gov (United States)

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.

Roy, S. Deb; Beig, G.; Ghude, Sachin D.

2009-07-01

74

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; G. Beig; Sachin D. Ghude

2009-01-01

75

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

Directory of Open Access Journals (Sweden)

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

Hunova I; Schreiberova M

2012-01-01

76

Effects of ozone on photosynthesis, vegetative growth, and development of woody perennials in the San Joaquin Valley of California. Final report  

Energy Technology Data Exchange (ETDEWEB)

Nursery stock of nine fruit and nut tree species 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. The trees were then exposed to three levels of atmospheric ozone partial pressures (charcoal filtered air, ambient air, or ambient air + ozone) from 1 August to 17 November 1988. The relationship between leaf net CO2 assimilation rate and 12-hour mean ozone partial pressure decreased linearly with increasing ozone partial pressure for the almond, plum, apricot, pear and apple cultivars. Stomatal conductances of apricot, prune, apple, almond, and plum also decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, pear and apple declined linearly with increasing ozone partial pressure. Net CO2 assimilation rate, stomatal conductance, and trunk growth of cherry, peach, and nectarine were unaffected by the ozone treatments. The results indicate that decreases in leaf gas exchange were probably contributors to decreases in young tree growth of the susceptible species/cultivars.

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

1989-10-31

77

Does ozone exposure alter growth and carbon allocation of mycorrhizal plants  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-06-01

78

Measuring ambient carbonyls using DNPH-coated substrates: Comparison of C18 and silica gel with and without ozone scrubbers  

Energy Technology Data Exchange (ETDEWEB)

Carbonyls in ambient air play a critical role in atmospheric chemistry, including ozone formation on urban and regional scales. Recently mandated requirements to report ambient levels of formaldehyde and other carbonyls as part of the nationwide PAMS monitoring program underline the importance of obtaining reliable, interference-free data when measuring ppb levels of carbonyls in urban air. The DNPH-liquid chromatography method, initially described by Kuwata et al. in Japan and by Grosjean and Fung in the US, has since been endorsed by ASTM, EPA and other agencies; this method has been suggested by EPA as the method of choice for PAMS monitoring of ambient levels of carbonyls measured using co-located C18 and silica gel substrates with and without scrubbers to remove ambient ozone. As part of this study, the performance of several types of ozone scrubbers has been evaluated. The results will be discussed with special emphasis on PAMS requirements for monitoring of ambient carbonyls by state and local air pollution control agencies.

Grosjean, D.; Grosjean, E. [DGA, Inc., Ventura, CA (United States)

1994-12-31

79

Detecting plant effects is necessary to give biological significance to ambient ozone monitoring data and predictive ozone standards.  

UK PubMed Central (United Kingdom)

The use of mechanical monitors and passive samplers has made it possible to assess concentrations of ozone over wide areas and to develop air quality standards, like AOT40 and SUM60. Monitored ozone data and AOT40 and SUM60 are also used to predict ozone injury on local and regional scales. The data and the standards do not include or account for environmental and biological variables that affect ozone uptake and plant injury. Ground proofing via vegetation surveys must be done to verify and validate plant injury predictions. If this is not done, then the standards have no biological significance and are only exercises in air quality assessment.

Manning WJ

2003-01-01

80

Detecting plant effects is necessary to give biological significance to ambient ozone monitoring data and predictive ozone standards.  

Science.gov (United States)

The use of mechanical monitors and passive samplers has made it possible to assess concentrations of ozone over wide areas and to develop air quality standards, like AOT40 and SUM60. Monitored ozone data and AOT40 and SUM60 are also used to predict ozone injury on local and regional scales. The data and the standards do not include or account for environmental and biological variables that affect ozone uptake and plant injury. Ground proofing via vegetation surveys must be done to verify and validate plant injury predictions. If this is not done, then the standards have no biological significance and are only exercises in air quality assessment. PMID:12963300

Manning, William J

2003-01-01

 
 
 
 
81

Growth response to ozone of annual species from Mediterranean pastures  

International Nuclear Information System (INIS)

Ozone (O3) phytotoxicity has been reported on a wide range of plant species. However, scarce information has been provided regarding the sensitivity of semi-natural grassland species, especially those from dehesa Mediterranean grasslands, in spite of their great biological diversity and the high O3 levels recorded in the region. A screening study was carried out in open-top chambers (OTCs) to assess the O3-sensitivity of representative therophytes of these ecosystems based on the response of selected growth-related parameters. Three O3 treatments and 3 OTCs per treatment were used. Legume species were very sensitive to O3, because 78% of the tested species showed detrimental effects on their total biomass relative growth rate (RGR) following their exposure to O3. The Trifolium genus was particularly sensitive showing O3-induced adverse effects on most of the assessed parameters. Gramineae plants were less sensitive than Leguminosae species because detrimental effects on total biomass RGR were only observed in 14% of the assessed species. No relationship was found between relative growth rates when growing in clean air and O3 susceptibility. The implications of these effects on the performance of dehesa acidic grasslands and on the definition of ozone critical levels for the protection of semi-natural vegetation are discussed. - Capsule: The therophytes from dehesa acidic pastures of central of the Iberian peninsula present a great sensitivity to ozone, as derived from growth- and biomass-related variables.

2004-01-01

82

The short-term effect of ambient ozone on mortality is modified by temperature in Guangzhou, China  

Science.gov (United States)

Effects of ozone on mortality have been widely assessed in developed countries but rarely in developing countries, and the effects of season and temperature on these associations remain unclear. The present study aimed to explore the modifying effects of temperature on the association of ozone with mortality, and to examine the lag effect structure in Guangzhou, China. Daily non-accidental mortality, air pollution and meteorological data from January 1st 2006 to December 31st 2008 in Guangzhou were collected. Generalized additive models (GAM) and distributed lag models (DLM) were used to estimate the excess risk (ER) of ozone on daily mortality and capture the lag effect structure. Results revealed that, in cold season, an increment in the ozone concentration of 10 ?g m?3 was associated with a 0.87% (95% CI: ?0.06 to 2.29%) and 3.34% (95%CI: 1.36–5.35%) increase of mortality for lag0 and lag0–6, respectively. However, no significant effects were observed in the warm season. Daily average temperature and ozone concentration had interactive negative effects on non-accidental mortality in the cold season and at daily average temperatures in the 0–25th percentile, and mortality displacement was also found in these conditions. Therefore, the short-term effect of ambient ozone on mortality is modified by temperature in Guangzhou, China.

Liu, Tao; Li, Tian Tian; Zhang, Yong Hui; Xu, Yan Jun; Lao, Xiang Qian; Rutherford, Shannon; Chu, Cordia; Luo, Yuan; Zhu, Qi; Xu, Xiao Jun; Xie, Hui Yan; Liu, Zhao Rong; Ma, Wen Jun

2013-09-01

83

Surface-level ozone exposures and their effects on vegetation  

Energy Technology Data Exchange (ETDEWEB)

This book focuses on the formation, distribution, and transport of surface-level ozone; the characterization of its exposures; the mechanisms and processes involved in its deposition and uptake by plants; and its effects on the growth of crops and forest trees. State-of-the-art information is presented and the methodology for studying its effects on vegetation is critically reviewed. Contents (Partial): Tropospheric Ozone: Formation and Fate. The Characterization of Ambient Ozone Exposures. Experimental Methodology for Studying the Effects of Ozone on Crops and Trees. Uptake of Ozone by Vegetation. Crop Responses to Ozone. Tree Responses to Ozone. Ozone Standards and Their Relevance for Protecting Vegetation.

Lefohn, A.S. (A.S.L. and Associates, Helena, MT (US))

1992-01-01

84

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

International Nuclear Information System (INIS)

[en] 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

1992-01-01

85

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

Science.gov (United States)

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

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

2006-06-21

86

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

Science.gov (United States)

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.

Mei, Zhao; Renrong, Liang; Jing, Wang; Jun, Xu

2013-06-01

87

Integrated biomonitoring of air quality with plants and lichens: a case study on ambient ozone from central Italy.  

UK PubMed Central (United Kingdom)

A biennial integrated survey, based on the use of vascular plants for the bioindication of the effects of tropospheric ozone together with the use of automatic analysers of ozone, as well as the mapping of lichen biodiversity was performed in the area of Castelfiorentino (Tuscany, central Italy). Photochemically produced ozone proved to be a fundamental presence during the warm season, with maximum hourly means reaching 114 ppb, exceeding the information threshold as fixed by EU: the use of supersensitive tobacco Bel-W3 confirmed the opportunity of carrying out detailed cost-effective monitoring surveys. The potential for didactical and educational implications of this methodology are appealing. Critical levels set up for the protection of vegetation have exceeded considerably. The comparison of biomass productivity in sensitive and resistant individuals (NC-S and NC-R white clover clones, in the framework of an European network) provided evidence that ambient ozone levels are associated with relevant reduction (up to 30%) in the performance of sensitive material; effects on flowering were also pronounced. The economic assessment of such an impact deserves attention. Mapping of epiphytic lichen biodiversity--which has been used to monitor air quality worldwide--was not related to ozone geographical distribution as depicted by tobacco response.

Nali C; Balducci E; Frati L; Paoli L; Loppi S; Lorenzini G

2007-05-01

88

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

Science.gov (United States)

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

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

2013-07-17

89

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

UK PubMed Central (United Kingdom)

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

Ali A; Ong MK; Forney CF

2014-01-01

90

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

Science.gov (United States)

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

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

2010-11-12

91

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.  

UK PubMed Central (United Kingdom)

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.

Sicard P; Dalstein-Richier L; Vas N

2011-02-01

92

Growth is compromised in rats fed ozone-treated casein  

Energy Technology Data Exchange (ETDEWEB)

Modified casein containing few phenylalanine residues and no other aromatic amino acid residues was obtained by ozonolysis of casein. Although 68% of phenylalanine was decomposed by ozonolysis of casein, ozonolysis caused alterations beyond the destruction of aromatic amino acid residues. Nearly the same degree of decomposition of amino acid residues was observed in casein ozonated after predigestion by pepsin. Rats were fed diets containing 8% casein supplemented with methionine and aspartic acid (8C-AA), 8% ozonated casein supplemented with methionine and free amino acids lost by ozonolysis (8OC-AA), 8% casein ozonated after predigestion by pepsin supplemented with methionine and free amino acids lost during preparation (8POC-AA) or 7.6% amino acid mixture. The growth of rats fed the 8OC-AA diet was significantly lower than that of those fed 8C-AA or 7.6AA diets. The growth of rats fed the 8POC-AA diet was comparable to growth of those fed 8OC-AA. The biological values of the 8OC-AA and 8POC-AA were comparable to that of 8C-AA, but true digestibility of 8OC-AA was significantly lower than that of 8C-AA. True digestibility 8POC-AA was significantly improved relative to 8OC-AA, but the growth of rats fed 8POC-AA was not improved relative to that of those fed 8OC-AA. Kidney and cecum weights of rats fed 8OC-AA and 8POC-AA were significantly heavier than those of the 8C-AA-fed group, although histopathological examination of kidneys showed no deterioration compared to that of the 8C-AA-fed group.

Kasai, T.; Iwashita, A.; Kiriyama, S. (Hokkaido Univ., Sapporo (Japan))

1993-05-01

93

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

International Nuclear Information System (INIS)

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

2011-01-01

94

Ozone  

Science.gov (United States)

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

95

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-02-15

96

Effects of ozone on Pinus ponderosa seedlings: comparison of responses in the first and second growing seasons of exposure  

Energy Technology Data Exchange (ETDEWEB)

The effects of ozone on the physiological and growth responses of ponderosa pine seedlings were investigated. The seedlings were exposed to three levels of ozone, i.e., in open-top chambers in charcoal-filtered air, in ambient, and in twice ambient concentrations. In the first growing season, current-year needles in twice ambient ozone exhibited significant needle injury; also periodic decreases in chlorophyll fluorescence and net photosynthesis. Plant growth, however, was not significantly affected. In the second growing season, one year-old needles of seedlings exposed to twice ambient ozone showed marked reductions in physiological and biochemical responses. Plant growth was decreased relative to seedlings exposed to open top chamber charcoal-filtered air, and ambient ozone level. These results indicate that decreases in growth by ambient ozone are insidious, and may not become fully evident until after tree or four years of exposure in situ. 30 refs., 6 tabs.,

Takemoto, B. K. [California Air Resources Board, Sacramento, CA (United States); Bytnerowicz, A. [Forest Service, Riverside CA (United States). Pacific Southwest Forest and Range Experiment Station; Dawson, P. J.; Morrison, C. L.; Temple, P. J. [California Univ., Riverside, CA (United States). Statewide Air Pollution Research Center

1997-01-01

97

PLATIN (plant-atmosphere interaction) II: Co-occurrence of high ambient ozone concentrations and factors limiting plant absorbed dose.  

UK PubMed Central (United Kingdom)

There is an ongoing debate as to which components of the ambient ozone (O3) exposure dynamics best explain adverse crop yield responses. A key issue is regarding the importance of peak versus mid-range hourly ambient O3 concentrations. While in this paper the importance of peak atmospheric O3 concentrations is not discounted, if they occur at a time when plants are conducive for uptake, the corresponding importance of more frequently occurring mid-range O3 concentrations is described. The probability of co-occurrence of high O3 concentrations and O3 uptake limiting factors is provided using coherent data sets of O3 concentration, air temperature, air humidity, mean horizontal wind velocity and global radiation measured at representative US and German air quality monitoring sites. Using the PLant-ATmosphere INteraction (PLATIN) model, the significance of the aforementioned meteorological parameters on ozone uptake is examined. In addition, the limitations of describing the O3 exposure for plants under ambient, chamberless conditions by SUM06, AOT40 or W126 exposure indices are discussed.

Grünhage L; Jäger HJ; Haenel HD; Hanewald K; Krupa S

1997-01-01

98

Lung carcinogenesis and splenomegaly following chronic ozone inhalation at ambient concentrations  

Energy Technology Data Exchange (ETDEWEB)

In the following studies, inbred strain A/J mice, which are responsible to the chemical induction of pulmonary adenomas, were used to assess any of several roles ozone might play in carcinogenesis. In separate experiments, animals were exposed intermittently to two concentrations of ozone for a six-month period in order to evaluate the potential of ozone to act as a pulmonary carcinogen, tumor promoter, or cocarcinogen. Statistical analyses of results indicate that ozone exposure to either concentration caused an increase in lung tumor nodules relative to air-breathing controls but that ozone at 0.31 ppm was not an effective tumor promoter under the exposure regimen employed. In addition, mice exposed to ozone at 0.31 ppm experienced an increase in spleen weight when compared to air-breathing controls. In some ozone-exposed animals, pronounced splenomegaly was observed. The results of these experiments indicate that chronic ozone inhalation at concentrations found in polluted urban air may have the potential to enhance pulmonary carcinogenesis and can cause a clearly recognizable response in an extrapulmonary organ such as the spleen.

Hassett, C.M.

1985-01-01

99

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

100

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

UK PubMed Central (United Kingdom)

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.

Parvanova P; Tzvetkova N; Bratanova-Doncheva S; Chipev N; Fikova R; Donev E

2013-07-01

 
 
 
 
101

Effects of ambient and elevated level of ozone on Brassica campestris L. with special reference to yield and oil quality parameters.  

UK PubMed Central (United Kingdom)

Tropospheric ozone (O(3)) has become a serious threat to growth and yield of important agricultural crops over Asian regions including India. Effect of elevated O(3) (ambient+10ppb) was studied on Brassica campestris L. (cv. Sanjukta and Vardan) in open top chambers under natural field conditions. Eight hourly mean ambient O(3) concentration varied from 26.3ppb to 69.5ppb during the growth period. Plants under O(3) exposure showed reductions in photosynthetic rate, reproductive parameters, yield as well as seed and oil quality. Cultivar Sanjukta showed more reduction in photosynthetic characteristics, reproductive structures and seed and oil quality. However, total yield was more affected in Vardan. Exposure of O(3) increased the degree of unsaturation and level of PUFA, ?-6fatty acid, linolenic acid and erucic acid in oil indicating the deterioration of its quality. The study further confirmed that there is a correspondence between O(3) induced change in photosynthetic processes, reproductive development and yield and did not find any compensatory response in the final yield.

Tripathi R; Agrawal SB

2012-11-01

102

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

2010-05-13

103

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-04-15

104

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

International Nuclear Information System (INIS)

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

2007-01-01

105

Assessing effects of ambient ozone on injury and yield of bean with ethylenediurea (EDU): three years of plant monitoring at four sites in The Netherlands.  

Science.gov (United States)

EDU (ethylenediurea) and non-EDU-treated bean plants (Phaseolus vulgaris L. cv. Lit) were exposed to ambient air at four rural sites in The Netherlands during the growing seasons of 1994 through 1996 to investigate the responses to ambient ozone. Ozone-induced foliar injury was observed each year and differences in injury between sites depended on year. On average, injury amounted to 27% in 1994, to 8% in 1995 and to 1% in 1996. Injury increased with increasing ozone exposure (AOT40) and the estimated AOT40 value corresponding with 5% injury was circa 3650 nl l(-1) h ozone. The highest ozone levels accumulated at each site for five consecutive days before injury exceeded the proposed short-term critical level for injury development. EDU reduced injury and its protective effect was positively related to the injury intensity in non-EDU-treated plants. Yield of green marketable pods (intermediate harvest) and mature pods (final harvest) was generally reduced in non-EDU-treated plants compared to EDU-treated plants and differences in yield reduction between harvests varied between years. The yield of mature pods was reduced in 1994 and 1996 while the yield of green pods was reduced in 1995 by ozone only. Since yield reduction was not correlated with AOT40. the EDU method was not valid to determine an ozone exposure-yield reponse relationship for bean. PMID:12139072

Tonneijck, A E G; Van Dijk, C J

2002-07-01

106

Assessing effects of ambient ozone on injury and yield of bean with ethylenediurea (EDU): three years of plant monitoring at four sites in The Netherlands.  

UK PubMed Central (United Kingdom)

EDU (ethylenediurea) and non-EDU-treated bean plants (Phaseolus vulgaris L. cv. Lit) were exposed to ambient air at four rural sites in The Netherlands during the growing seasons of 1994 through 1996 to investigate the responses to ambient ozone. Ozone-induced foliar injury was observed each year and differences in injury between sites depended on year. On average, injury amounted to 27% in 1994, to 8% in 1995 and to 1% in 1996. Injury increased with increasing ozone exposure (AOT40) and the estimated AOT40 value corresponding with 5% injury was circa 3650 nl l(-1) h ozone. The highest ozone levels accumulated at each site for five consecutive days before injury exceeded the proposed short-term critical level for injury development. EDU reduced injury and its protective effect was positively related to the injury intensity in non-EDU-treated plants. Yield of green marketable pods (intermediate harvest) and mature pods (final harvest) was generally reduced in non-EDU-treated plants compared to EDU-treated plants and differences in yield reduction between harvests varied between years. The yield of mature pods was reduced in 1994 and 1996 while the yield of green pods was reduced in 1995 by ozone only. Since yield reduction was not correlated with AOT40. the EDU method was not valid to determine an ozone exposure-yield reponse relationship for bean.

Tonneijck AE; Van Dijk CJ

2002-07-01

107

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

Science.gov (United States)

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

108

Instrumental recording and biomonitoring of ambient ozone in the Greek countryside.  

UK PubMed Central (United Kingdom)

Among eight commercial Greek varieties of tobacco (Nicotiana tabacum L.) tested for their ozone-sensitivity levels, the Zichnomirodata (KK6/5) variety was found to be the most sensitive, although less sensitive than the well-known super-sensitive Bel-W3. Besides qualitative differences in the appearance of macroscopic symptoms these two varieties can be used simultaneously as a reliable pair of ozone bioindicators. The occurrence of ozone in the Greek countryside was surveyed by biomonitoring in 14 rural regions over the country and by a simultaneous biomonitoring and instrumental recording of ozone concentrations at a single remote side (Pournaria, Arcadia). Phytotoxic symptoms were observed mainly on the leaves of Bel-W3 and occasionally on those of Zichnomirodata varieties, suggesting that ozone levels were high enough to affect at least sensitive species. The instrumental monitoring (during a total period of 912 h) revealed maximum hourly O3 concentration 62 ppb, while the thresholds of 30, 40 and 50 ppb were exceeded for 40%, 20% and 6% of the recording period, respectively. The accumulated exposure over 40 ppb (AOT40) for the daylight hours over the 38 monitored days was 680 ppb h.

Saitanis CJ; Karandinos MG

2001-08-01

109

Instrumental recording and biomonitoring of ambient ozone in the Greek countryside.  

Science.gov (United States)

Among eight commercial Greek varieties of tobacco (Nicotiana tabacum L.) tested for their ozone-sensitivity levels, the Zichnomirodata (KK6/5) variety was found to be the most sensitive, although less sensitive than the well-known super-sensitive Bel-W3. Besides qualitative differences in the appearance of macroscopic symptoms these two varieties can be used simultaneously as a reliable pair of ozone bioindicators. The occurrence of ozone in the Greek countryside was surveyed by biomonitoring in 14 rural regions over the country and by a simultaneous biomonitoring and instrumental recording of ozone concentrations at a single remote side (Pournaria, Arcadia). Phytotoxic symptoms were observed mainly on the leaves of Bel-W3 and occasionally on those of Zichnomirodata varieties, suggesting that ozone levels were high enough to affect at least sensitive species. The instrumental monitoring (during a total period of 912 h) revealed maximum hourly O3 concentration 62 ppb, while the thresholds of 30, 40 and 50 ppb were exceeded for 40%, 20% and 6% of the recording period, respectively. The accumulated exposure over 40 ppb (AOT40) for the daylight hours over the 38 monitored days was 680 ppb h. PMID:11482673

Saitanis, C J; Karandinos, M G

2001-08-01

110

Past and future ozone trends in California's South Coast Air Basin: reconciliation of ambient measurements with past and projected emission inventories.  

UK PubMed Central (United Kingdom)

UNLABELLED: This paper updates the historic trends (1980-2010) in ambient ozone and ozone precursor concentrations in the South Coast Air Basin (SoCAB) and examines the evolution of the ozone-precursor relationship in the Basin. Whereas reductions in NOx (oxide of nitrogen) emissions have decreased nitrate and PM2.5 (particulate matter with an aerodynamic diameter < or = 2.5 microm) concentrations in the Basin during the past decade, ozone levels have increased at the central basin locations since about 2005 following a reversal in the decline of volatile organic compound (VOC)/NOx ratios during the previous two decades. A chemical box model was used to simulate the effects of changes in precursor concentrations on ozone formation using day-of-week-specific initial precursor concentrations that were derived from measurements and'projected to 2020 based on expected emission reductions from 2005 (-10% VOC and -50% NOx). Results show that peak ozone formation rates in 2020 will increase on weekdays by a factor of 3 relative to 2005 and will be comparable to 1995 weekday and 2005 Sunday rates. Ozone production will become precursor limited on Sundays in 2020, but with higher initial rates than 2005. Although a greater NOx reduction scenario in 2020 of -75% will result in even higher initial ozone formation rates, precursor limitation is reached quickly, leading to a further shift westward in the location of peak ozone levels. However ozone levels will likely be lower in downwind areas where transport is more important than local production of ozone. The ambient versus emission inventory reconciliation indicates a factor of 2 underestimation of VOC emissions in 2009 relative to NOx. Other analyses suggest that there is an overall increase in VOC emissions on hot days that is not fully accounted for by emission inventory estimates. Air quality models using emission inventories that underestimate VOC emissions relative to NOx may lead to inaccurate forecasting of the consequence of emission reductions. IMPLICATIONS: The rate and efficiency of ozone formation and accumulation in the SoCAB is more rapid than would be indicated by air quality model simulations based on the current inventory. Projected reductions in NOx emissions without concurrent reductions in VOC emissions will likely cause ozone to increase during the next decade within central regions of the SoCAB compared with a flat or slightly declining trend in far downwind locations. Air quality statistics that are commonly used to track progress toward attainment, such as basin-wide ozone design value and standard exceedances mask these varying trends within the Basin.

Fujita EM; Campbell DE; Stockwell WR; Lawson DR

2013-01-01

111

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-04-15

112

Temperature, ambient ozone levels, and mortality during summer 1994, in Belgium.  

UK PubMed Central (United Kingdom)

The number of daily deaths, temperature, relative humidity, and 24-hr concentrations of main air pollutants observed during a heat wave (June 27-August 7, 1994) in Belgium were compared with those recorded before and after this heat wave. All these variables were averaged over the country. Expected mortality was calculated from daily deaths observed during the summers of 1985-1993. The influence of meteorological and air pollution variables on daily mortality was analyzed using generalized least-squares method. Mortality recorded during the heat wave was higher than expected: it increased by 9.4% in the age group 0-64 years (236 excess deaths; P < 0.001) and by 13.2% in the elderly (1168 excess deaths; P < 0.001). After the heat wave, mortality in the elderly was lower than expected (178 deficit deaths; P< 0.05); the net excess of mortality in the whole population amounted to 1226 deaths when accounting for this deficit. This increased mortality was associated with unusually high outdoor temperatures (range of daily mean: 15.3-27.5 degrees C) and elevated ozone levels (range of 24-hr concentration: 34.5-111.5 microg/m3). The duration of the ozone overexposure during the heat wave was also uncommon: half-hour concentrations of ozone exceeded, on an average, 100 microg/m3 for 8 consecutive hr. The number of daily deaths was mostly correlated with the mean daily temperature and 24-hr ozone concentration, both measured the day before. A synergy between temperature and ozone in their effects on mortality was also highlighted in both age groups. The product of the logarithm of temperature by the logarithm of ozone concentration, both measured the day before, contributed to 39.5% of the variance of the logarithm of daily deaths in elderly and to 4.5% in the age group 0-64 years. In conclusion, elevated outdoor temperatures combined with high ozone concentrations were assumed to be the likely cause of the important excess mortality observed in Belgium during the summer, 1994.

Sartor F; Snacken R; Demuth C; Walckiers D

1995-08-01

113

Growth and respiration of aspen roots exposed to ozone and elevated carbon dioxide  

Energy Technology Data Exchange (ETDEWEB)

Rooted cuttings of three aspen clones (271, O[sub 3] tolerant; 216, intermediate; and 259, O[sub 3] sensitive) were exposed to ambient air (control), ozone (160 ppm O[sub 3] 8 h daily), CO[sub 2] (ambient +350 ppm CO[sub 2]), and O[sub 3] + CO[sub 2], and O[sub 3] + CO[sub 2]. Root growth, root respiration, and soil respiration were measured periodically for 12 weeks. After 12 weeks, O[sub 3] caused up to a 48% decrease in root dry weight and 53% decrease in root respiration ([mu]mol plant[sup [minus]1]s[sup [minus]1]) compared to control treatments. Changes in root dry weight and respiration rate generally followed the O[sub 3] sensitivity rankings of the clones. In contrast, elevated CO[sub 2] vs. control plants caused up to a 63% increase rate generally followed the O[sub 3] sensitivity rankings of the clones. In contrast, elevated CO[sub 2] vs. control plants caused up to a 63% increase in root dry weight and a 47% increase in root respiration; again there were big clonal differences in response. Compared to the control treatment, there were no consistent changes in root weight due to the combined O[sub 3] and CO[sub 2] treatment, by root system respiration declined slightly. There were no consistent treatment or clonal effects on specific root respiration (SRR) ([mu]mol g[sup [minus]1]s[sup [minus]1]); however, SRR respiration declined with age. SRR increased with either O[sub 3] or elevated CO[sub 2]for clones 216 and 259, but decreased for clone 217. Aboveground environmental stress affects aspen root growth and physiology in complex ways, and the response obtained has a strong genetic component.

Coleman, M.D.; Dickson, R.E.; Isebrands, J.G. (USDA Forest Service, Rhinelander, WI (United States))

1994-06-01

114

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.  

Science.gov (United States)

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. PMID:22035928

Neufeld, Howard S; Peoples, Seth J; Davison, Alan W; Chappelka, Arthur H; Somers, Greg L; Thomley, Jill E; Booker, Fitzgerald L

2011-10-14

115

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

Science.gov (United States)

In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. PMID:19850384

Olbrich, Maren; Knappe, Claudia; Wenig, Marion; Gerstner, Elke; Häberle, Karl-Heinz; Kitao, Mitsutoshi; Matyssek, Rainer; Stich, Susanne; Leuchner, Michael; Werner, Herbert; Schlink, Katja; Müller-Starck, Gerhard; Welzl, Gerhard; Scherb, Hagen; Ernst, Dieter; Heller, Werner; Bahnweg, Günther

2009-10-21

116

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

UK PubMed Central (United Kingdom)

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

Olbrich M; Knappe C; Wenig M; Gerstner E; Häberle KH; Kitao M; Matyssek R; Stich S; Leuchner M; Werner H; Schlink K; Müller-Starck G; Welzl G; Scherb H; Ernst D; Heller W; Bahnweg G

2010-04-01

117

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

Science.gov (United States)

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

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

2001-10-01

118

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

UK PubMed Central (United Kingdom)

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

Oksanen E; Amores G; Kokko H; Amores JM; Kärenlampi L

2001-10-01

119

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

International Nuclear Information System (INIS)

The hypothesis was tested that O3-induced changes in leaf-level photosynthetic parameters have the capacity of limiting the seasonal photosynthetic carbon gain of adult beech trees. To this end, canopy-level photosynthetic carbon gain and respiratory carbon loss were assessed in European beech (Fagus sylvatica) by using a physiologically based model, integrating environmental and photosynthetic parameters. The latter were derived from leaves at various canopy positions under the ambient O3 regime, as prevailing at the forest site (control), or under an experimental twice-ambient O3 regime (elevated O3), as released through a free-air canopy O3 fumigation system. Gross carbon gain at the canopy-level declined by 1.7%, while respiratory carbon loss increased by 4.6% under elevated O3. As this outcome only partly accounts for the decline in stem growth, O3-induced changes in allocation are referred to and discussed as crucial in quantitatively linking carbon gain with stem growth. - Highlights: ? We model O3-induced changes in the photosynthetic carbon gain of adult beech trees. ? Elevated O3 decreases gross carbon gain but increases respiratory carbon loss. ? Reduction in net carbon gain only partly accounts for the decline in stem growth. ? O3 effects on the whole-tree allocation is crucial in addition to carbon gains. - Reduction in net carbon gain at the canopy level only partly accounts for the decline in stem growth under elevated ozone.

2012-01-01

120

Determining VOC boundary values for simulations of Phoenix, AZ ozone with limited ambient measurements  

Energy Technology Data Exchange (ETDEWEB)

For Urban Airshed Model simulations of ozone episodes in 1992 and 1996 for Phoenix, AZ, numerous attempts to better characterize boundary conditions were made. The early boundary values relied on concentrations from urban sites that were adjusted to rural values, and ended with background VOC monitoring 50 miles west of Phoenix. Early attempts at specifying lateral boundary values for VOC depended on adjusting central city concentrations to boundary values based on simultaneous measurements with a limited analytical suite of 20 samples at a single boundary location and at three locations in the central city in 1992. Although these boundary values were refined and revised, their values proved to be too high to give a realistic boundary contribution to metropolitan ozone. These boundary values were lowered by incorporating hourly wind directions. Wind from the urban area led to a higher VOC value at a boundary segment, while wind from the rural area led to a lower VOC value at the boundary segment. These wind-directional dependent, spatially-varying boundary values were used in the final UAM model validation for a March, 1997 report. Evidence that these values were still too high, however, prompted a test with data from the remote location of Hillside, AZ, 80 miles northwest of Phoenix. These data consisted of only 53 hydrocarbons and 10 aldehydes, with no measurement of ethene. Boundary values based on these data produced ozone concentrations about 5% lower than the rural-urban, wind-direction dependent scheme. A special sampling program, conducted in May and June, 1997 at a site 50 miles west of Phoenix, provided data, that, when combined with the full Hillside data set, were sufficient to calculate optimal boundary concentrations for an October, 1997 report.

Hyde, P.; Oliver, W.R.; Heisler, S.L.; Tran, K. [Arizona Dept. of Environmental Quality, Phoenix, AZ (United States)]|[Radian International LLC (United States)]|[ENSR Consulting and Engineering (United States)]|[Applied Modeling, Inc. (United States)

1998-12-31

 
 
 
 
121

Differences in leaf characteristics between ozone-sensitive and ozone-tolerant hybrid aspen (Populus tremula x Populus tremuloides) clones.  

UK PubMed Central (United Kingdom)

The authors analyzed a suite of leaf characteristics that might help to explain the difference between ozone-sensitive and ozone-tolerant hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) clones. An open-field experiment comprising ambient ozone and 1.5x ambient ozone concentration (about 35 ppb) and two soil nitrogen regimes (60 and 140 kg N ha(-1) year(-1)) was conducted over two growing seasons on potted plants of eight hybrid aspen clones. Four of the clones had previously been determined to be ozone sensitive based on impaired growth in response to elevated ozone concentration. Photosynthetic rate, chlorophyll fluorescence, and concentrations of chlorophyll, protein and carbohydrates were analyzed three times during the second growing season, and foliar phenolic concentrations were measured at the end of the second growing season. Nitrogen amendment counteracted the effects of ozone, but had no effect on growth-related ozone sensitivity of the clones. Ozone-sensitive clones had higher photosynthetic capacity and higher concentrations of Rubisco and phenolics than ozone-tolerant clones, but the effects of ozone were similar in the sensitive and tolerant groups. Nitrogen addition had no effect on phenolic concentration, but elevated ozone concentration increased the concentrations of chlorogenic acid and (+)-catechin. This study suggests that condensed tannins and catechin, but not salicylates or flavonol glycosides, play a role in the ozone tolerance of hybrid aspen.

Häikiö E; Freiwald V; Julkunen-Tiitto R; Beuker E; Holopainen T; Oksanen E

2009-01-01

122

Differences in leaf characteristics between ozone-sensitive and ozone-tolerant hybrid aspen (Populus tremula x Populus tremuloides) clones.  

Science.gov (United States)

The authors analyzed a suite of leaf characteristics that might help to explain the difference between ozone-sensitive and ozone-tolerant hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) clones. An open-field experiment comprising ambient ozone and 1.5x ambient ozone concentration (about 35 ppb) and two soil nitrogen regimes (60 and 140 kg N ha(-1) year(-1)) was conducted over two growing seasons on potted plants of eight hybrid aspen clones. Four of the clones had previously been determined to be ozone sensitive based on impaired growth in response to elevated ozone concentration. Photosynthetic rate, chlorophyll fluorescence, and concentrations of chlorophyll, protein and carbohydrates were analyzed three times during the second growing season, and foliar phenolic concentrations were measured at the end of the second growing season. Nitrogen amendment counteracted the effects of ozone, but had no effect on growth-related ozone sensitivity of the clones. Ozone-sensitive clones had higher photosynthetic capacity and higher concentrations of Rubisco and phenolics than ozone-tolerant clones, but the effects of ozone were similar in the sensitive and tolerant groups. Nitrogen addition had no effect on phenolic concentration, but elevated ozone concentration increased the concentrations of chlorogenic acid and (+)-catechin. This study suggests that condensed tannins and catechin, but not salicylates or flavonol glycosides, play a role in the ozone tolerance of hybrid aspen. PMID:19203932

Häikiö, Elina; Freiwald, Vera; Julkunen-Tiitto, Riitta; Beuker, Egbert; Holopainen, Toini; Oksanen, Elina

2008-12-03

123

AMBIENT HYDROCARBON AND OZONE CONCENTRATIONS NEAR A REFINERY, BENICIA, CALIFORNIA, 1975  

Science.gov (United States)

As part of an effort to characterize airborne emissions from petroleum refineries, an ambient air monitoring study was conducted near the Exxon refinery at Benicia, California, during September 8-22, 1975. Ground-level sampling facilities and an airplane equipped with air polluta...

124

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

International Nuclear Information System (INIS)

[en] The effects of foliar applications of ethylenediurea (EDU) on responses to ozone by field-grown bush bean (Phaseolus vulgaris L.) lines 'S156' (O3-sensitive) and 'R123' (O3-tolerant), and cultivars 'BBL 290' (O3-sensitive) and 'BBL 274' (O3-tolerant) were investigated during the 2001 and 2002 growing seasons. EDU was applied weekly to designated plants between primary leaf expansion and pod senescence. Results were compared with control plants at harvests made at pod maturation and pod senescence. In 2001, average hourly ambient O3 concentrations ranged between 41 and 59 ppb for a total of 303 h; in 2002, for 355 h. EDU applications prior to pod maturation significantly increased the number of marketable pods in 'R123', but not for the other cultivars. Harvests at pod senescence showed significant improvements in crop yield production in EDU-treated 'S156' plants, whereas for EDU-treated 'R123' plants significant reductions were determined in above-ground biomass and seed production. In contrast, results from 'BBL 290' and 'BBL 274' at both harvest points were inconclusive. Growth and reproductive responses of O3-sensitive and O3-tolerant bush bean plants to EDU applications varied, depending on developmental stages, duration of EDU applications, and fluctuations in ambient O3. - Plant sensitivity to ozone, stage of plant development, number of applications of EDU and ambient ozone affect bean plant responses to EDU

2005-01-01

125

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

International Nuclear Information System (INIS)

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

2010-12-15

126

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

International Nuclear Information System (INIS)

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

127

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

Energy Technology Data Exchange (ETDEWEB)

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

Karlsson, P.E.; Uddling, J.; Skaerby, L.; Wallin, G.; Sellden, G

2003-08-01

128

Potential effects of ozone, climate, and spruce budworm on Douglas-fir growth in the Wasatch Mountains  

Energy Technology Data Exchange (ETDEWEB)

The potential for ozone injury to vegetation in the central Wasatch Mountains of Utah was assessed by determining growth changes in Douglas-fir since the onset of high ozone concentrations. Results showed reduced radial growth in Douglas-fir from the central Wasatch Mountains that could not be explained by climate or disturbance records. The correlation between reduced growth and ozone concentration suggests that high concentrations of ozone at this location may be the factor responsible for the reduced growth of Douglas-fir. However, due to a variety of possible factors, such as undetected climate, fungal pathogens, or competitive interactions may also influence Douglas-fir growth. Therefore, the evidence obtained in this study is not sufficiently conclusive to demonstrate a cause-and-effect relationship between elevated ozone levels and reduced growth. 46 refs., 4 tabs., 8 figs.

Wager, D. J. [Scientific Certification Systems, Emeryville, CA (United States); Baker, F. A. [Utah State University, Dept. of Forest Resources and Ecology Center, Logan, UT (United States)

2003-05-01

129

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

International Nuclear Information System (INIS)

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

2005-01-01

130

Ambient Ozone Concentrations and the Risk of Perforated and Nonperforated Appendicitis: A Multicity Case-Crossover Study  

Science.gov (United States)

Background: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. Objectives: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. Methods: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. Results: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). Conclusions: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis.

Tanyingoh, Divine; Dixon, Elijah; Johnson, Markey; Wheeler, Amanda J.; Myers, Robert P.; Bertazzon, Stefania; Saini, Vineet; Madsen, Karen; Ghosh, Subrata; Villeneuve, Paul J.

2013-01-01

131

Ambient ozone concentrations and the risk of perforated and nonperforated appendicitis: a multicity case-crossover study.  

UK PubMed Central (United Kingdom)

BACKGROUND: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. OBJECTIVES: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. METHODS: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. RESULTS: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). CONCLUSIONS: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis.

Kaplan GG; Tanyingoh D; Dixon E; Johnson M; Wheeler AJ; Myers RP; Bertazzon S; Saini V; Madsen K; Ghosh S; Villeneuve PJ

2013-08-01

132

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-08-15

133

Using ambient ozone for assignment of double bond position in unsaturated lipids.  

UK PubMed Central (United Kingdom)

Unsaturated lipids deposited onto a range of materials are observed to react with the low concentrations of ozone present in normal laboratory air. Parent lipids and ozonolysis cleavage products are both detected directly from surfaces by desorption electrospray ionisation mass spectrometry (DESI-MS) with the resulting mass spectra providing clear evidence of the double bond position within these molecules. This serendipitous process has been coupled with thin-layer chromatography (TLC) to provide a simple but powerful approach for the detailed structural elucidation of lipids present in complex biological extracts. Lipid extracts from human lens were deposited onto normal phase TLC plates and then developed to separate components according to lipid class. Exposure of the developed plates to laboratory air for ca. 1 h prior to DESI-MS analysis gave rise to ozonolysis products allowing for the unambiguous identification of double bond positions in even low abundant, unsaturated lipids. In particular, the co-localization of intact unsaturated lactosylceramides (LacCer) with products from their oxidative cleavage provide the first evidence for the presence of three isomeric LacCer (d18:0/24:1) species in the ocular lens lipidome, i.e., variants with double bonds at the n-9, n-7 and n-5 positions.

Ellis SR; Hughes JR; Mitchell TW; in het Panhuis M; Blanksby SJ

2012-03-01

134

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

135

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

Science.gov (United States)

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

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

136

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

UK PubMed Central (United Kingdom)

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

Ruhland CT; Xiong FS; Clark WD; Day TA

2005-09-01

137

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

138

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

Science.gov (United States)

Saplings of one half-sib family of birch, Betula pendula, were exposed to three levels of ozone in open-top chambers (OTCs) during two growing seasons 1997-1998. The ozone treatments were non-filtered air (NF, accumulated daylight AOT40 over the two growing seasons of 3.0 l l-1 h), non-filtered air with extra ozone (NF+, accumulated daylight AOT40 of 27.3 l l-1 h) and non-filtered air with additional extra ozone (NF++, accumulated daylight AOT40 of 120 l l-1 h). The birch saplings, including the roots, were harvested after the first and second growing seasons. After the first growing season, the NF++ treatment reduced the total wood biomass by 22%, relative to the NF treatment. There was no further reduction of the total wood biomass in the NF++ treatment after the second growing season. The root biomass was reduced by 30% after the first growing season. The shoot/root ratio, as well as the proportional biomass of leaves, were increased by ozone during both years. The ozone impact on the relative growth rate was estimated to -2% per 10 l l-1 h daylight AOT40 per growing season. PMID:12758028

Karlsson, P E; Uddling, J; Skärby, L; Wallin, G; Selldén, G

2003-01-01

139

Bioassaying for ozone with pollen systems  

Energy Technology Data Exchange (ETDEWEB)

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

Feder, W.A.

1981-01-01

140

Ozone; Ozon  

Energy Technology Data Exchange (ETDEWEB)

The present report contains the lectures held at the expert meeting on `Ozone` and further relevant contributions on the ozone problem. The concluding contribution on `Ozone and industrial safety` summarises the main points of the individual lectures with due consideration to aspects mentioned in the discussion and presents concepts for possible industrial safety regulations that were elaborated in the course of the meeting. (orig./MG) [Deutsch] Bei dem vom BIA in Abstimmung mit dem Bundesministerium fuer Arbeit und Sozialordnung (BMA) und dem Ausschuss fuer Gefahrstoffe durchgefuehrten Fachgespraech `Ozon` wurde die Ozonproblematik von allen Seiten dargestellt und mit ausgewiesenen Fachleuten eroertert. Der vorliegende Report enthaelt die beim Fachgespraech `Ozon` gehaltenen Vortraege sowie weitere relevante Beitraege zur Ozonproblematik. In dem abschliessenden Beitrag `Ozon und Arbeitsschutz` werden die Kernaussagen der einzelnen Vortraege unter Beruecksichtigung der in der Diskussion angesprochenen Aspekte zusammengefasst und die waehrend des Fachgespraechs erarbeiteten Konzepte fuer moegliche Arbeitsschutzregelungen dargestellt. (orig./MG)

Smola, T. [comp.] [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Blome, H. [comp.] [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany)

1996-09-01

 
 
 
 
141

Ambient ozone concentrations cause increased hospitalizations for asthma in children: an 18-year study in Southern California.  

UK PubMed Central (United Kingdom)

BACKGROUND: Asthma is the most important chronic disease of childhood. The U.S. Environmental Protection Agency has concluded that children with asthma continue to be susceptible to ozone-associated adverse effects on their disease. OBJECTIVES: This study was designed to evaluate time trends in associations between declining warm-season O(3) concentrations and hospitalization for asthma in children. METHODS: We undertook an ecologic study of hospital discharges for asthma during the high O(3) seasons in California's South Coast Air Basin (SoCAB) in children who ranged in age from birth to 19 years from 1983 to 2000. We used standard association and causal statistical analysis methods. Hospital discharge data were obtained from the State of California; air pollution data were obtained from the California Air Resources Board, and demographic data from the 1980, 1990, and 2000 U.S. Census. SoCAB was divided into 195 spatial grids, and quarterly average O(3), sulfurdioxide, particulate matter with aerodynamic diameter < or = 10 microm, nitrogen dioxide, and carbon monoxide were assigned to each unit for 3-month periods along with demographic variables. RESULTS: O(3) was the only pollutant associated with increased hospital admissions over the study period. Inclusion of a variety of demographic and weather variables accounted for all of the non-O(3) temporal changes in hospitalizations. We found a time-independent, constant effect of ambient levels of O(3) and quarterly hospital discharge rates for asthma. We estimate that the average effect of a 10-ppb mean increase in any given mean quarterly 1-hr maximum O(3) over the 18-year median of 87.7 ppb was a 4.6% increase in the same quarterly outcome. CONCLUSIONS: Our data indicate that at current levels of O(3) experienced in Southern California, O(3) contributes to an increased risk of hospitalization for children with asthma.

Moore K; Neugebauer R; Lurmann F; Hall J; Brajer V; Alcorn S; Tager I

2008-08-01

142

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.

2003-01-01

143

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

UK PubMed Central (United Kingdom)

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

Kohno Y; Matsumura H; Miwa M; Yonekura T; Aihara K; Umponstira C; Le VT; Ngoc NT; Viet PH; Wei M

2013-03-01

144

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...

145

Associations between ambient ozone, hydrocarbons, and childhood wheezy episodes: a prospective observational study in south east London  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES—To explore the hypothesis that hydrocarbon species and other air pollutants which accumulate at low and high concentrations of ozone are more directly associated with childhood wheezy episodes than ozone.?METHODS—Prospective observational study over 1 year set in the Lewisham district of ...

Buchdahl, R.; Willems, C. D.; Vander, M.; Babiker, A.

146

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-08-15

147

Associations between ambient ozone, hydrocarbons, and childhood wheezy episodes: a prospective observational study in south east London.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To explore the hypothesis that hydrocarbon species and other air pollutants which accumulate at low and high concentrations of ozone are more directly associated with childhood wheezy episodes than ozone. METHODS: Prospective observational study over 1 year set in the Lewisham district of south east London. The daily attendance rate of children with acute wheeze at the accident and emergency department of Lewisham Hospital was related to local measurements of ozone, hydrocarbon species, nitrogen dioxide (NO2), sulphur dioxide (SO2) and small particulate matter with diameter < 10 microns (PM10). RESULTS: An inverse relation was found between the air pollutants and ozone. After seasonal and meteorological adjustment a non-linear U shaped trend was found between incidence of wheeze and ozone. The trend was significant in children < 2 years of age but not in older children. In the younger age group, after adjustment for season, temperature, wind speed, and respiratory infection, the incidence relative to that at the mean daily ozone concentration of 32.7 micrograms/m3, was estimated to increase by 65% (95% confidence interval (95% CI) 22% to 122%) at an ozone concentration of 5 micrograms/m3 (1.5 SDs below the mean) and by 63% (95% CI -6% to 184%) at 80 micrograms/m3 (2.5 SDs above the mean). For several hydrocarbons there were significant positive linear relations found, again in children < 2 years of age but not older children. For benzene, the incidence increased by 8% (95% CI 2 to 13%) per SD (SD 2.8 micrograms/m3) increase in benzene concentration. A same day association between incidence and ozone was found to be the most significant but for other pollutants a lag of 2 days gave the most significant associations. No significant association was found for the non-hydrocarbon pollutants including SO2, NO2, and PM10. CONCLUSIONS: A U shaped relation was found between ozone and the incidence of wheezy episodes in young children. Certain hydrocarbon pollutants accumulate in the atmosphere when ozone concentrations are low, and are associated with childhood wheezy episodes. However, the U shaped association of ozone on incidence cannot be explained by these other pollutants. The finding supports an earlier finding that incidences of wheeze are at a minimum when ozone concentrations are 30-40 micrograms/m3.

Buchdahl R; Willems CD; Vander M; Babiker A

2000-02-01

148

Development of a multi-factor model for predicting the effects of ambient ozone on the biomass of white clover.  

UK PubMed Central (United Kingdom)

Results are presented from the UN/ECE ICP Vegetation (International Cooperative Programme on effects of air pollution on natural vegetation and crops) experiments in which ozone(O(3))-resistant (NC-R) and -sensitive (NC-S) clones of white clover (Trifolium repens cv. Regal) were exposed to ambient O(3) episodes at 14 sites in eight European countries in 1996, 1997 and 1998. The plants were grown according to a standard protocol, and the forage was harvested every 28 days for 4-5 months per year by excision 7 cm above the soil surface. Biomass ratio (NC-S/NC-R) was related to the climatic and pollutant conditions at each site using multiple linear regression (MLR) and artificial neural networks (ANNs). Twenty-one input parameters [e.g. AOT40, 7-h mean O(3) concentration, daylight vapour pressure deficit (VPD), daily maximum temperature] were considered individually and in combination with the aim of developing a model with high r(2) and simple structure that could be used to predict biomass change in white clover. MLR models were generally more complex, and performed less well for unseen data than non-linear ANN models. The ANN model with the best performance had five inputs with an r(2) value of 0.84 for the training data, and 0.71 for previously unseen data. Two inputs to the model described the O(3) conditions (AOT40 and 24-h mean for O(3)), two described temperature (daylight mean and 24-h mean temperature), and the fifth input appeared to be differentiating between semi-urban and rural sites (NO concentration at 17:00). Neither VPD nor harvest interval was an important component of the model. The model predicted that a 5% reduction in biomass ratio was associated with AOT40s in the range 0.9-1.7 ppm x h (microl l(-1) h) accumulated over 28 days, with plants being most sensitive in conditions of low NO(x), medium-range temperature, and high 24-h mean O(3) concentration.

Mills G; Ball G; Hayes F; Fuhrer J; Skärby L; Gimeno B; De Temmerman L; Heagle A

2000-09-01

149

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

150

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

UK PubMed Central (United Kingdom)

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.

Prozherina N; Nakvasina E; Oksanen E

2009-12-01

151

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

Science.gov (United States)

...use by asthmatics, doctor visits, and emergency department visits and hospital admissions for individuals with respiratory disease. Ozone exposure may also contribute to premature death, especially in people with heart and lung disease....

2012-06-11

152

Ozone; Ozon  

Energy Technology Data Exchange (ETDEWEB)

Following the German Research Association`s classification of ozone as a `substance justifiably suspected of being potentially carcinogenic` at the beginning of this year, major problems arose as to how these findings could be incorporated into legislation and occupational safety in practice. This is a particularly difficult question to answer given that is scarcely possible to use technical measures to provide employees working outdoors (e.g. roofers, road construction workers) with protection from the high concentration of ozone which occurs in summer. The results of the specialist discussion presented in this Report can be incorporated as appropriate into the recommendations specific to individual sectors made by the Berufsgenossenschaften or by the state inspectorate, as well as into the BMA`s rules on the protection of employers from ozone, be the presence of ozone the result of environmental conditions or of industrial processes. (orig.)

Smola, T. [comp.] [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Blome, H. [comp.] [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany)

1995-12-01

153

Growth and physiological responses to ozone and mild drought stress of tree species with different ecological requirements  

UK PubMed Central (United Kingdom)

An open-top chamber experiment was carried out in Curno (Northern Italy) in 2004 and 2005 on seedlings of Fagus sylvatica (FS), Quercus robur (QR), and an ozone-sensitive Populus (POP) clone, to investigate the role of two stress factors: tropospheric ozone and water shortage. Treatments were filtered air to achieve a 50% reduction in the environmental ozone concentrations (charcoal filtered, CF); and non-filtered air, with a 5% reduction in the environmental ozone concentrations (non-filtered, NF). Overall ozone exposure (AOT40) in open air (April-September) was 26,995 ppb h in 2004 and 25,166 ppb h in 2005. The plants were either watered (W) or not watered (dry, D). We investigated the above-ground biomass, tree-ring growth, stable carbon isotopes ratio, i.e. ?¹³C of tree rings, and the photosynthetic parameter Driving forces (DFABS), derived from chlorophyll a fluorescence analysis. Ozone-induced growth reduction (in terms of biomass) in POP, and that reduction was more pronounced in D plots. A synergistic effect of ozone and drought stress was evidenced by DFABS in POP and QR, but not in FS. The water availability was revealed as the main factor influencing the isotopic ratio ?¹³C. In drought-stressed seedlings, the increase in ?¹³C value was accompanied by the reduction in stomatal conductance and increased DFABS. Fast-growing plant species with high water requirements are more susceptible to ozone and drought stress.

Pollastrini Martina; Desotgiu Rosanna; Cascio Chiara; Bussotti Filippo; Cherubini Paolo; Saurer Matthias; Gerosa Giacomo; Marzuoli Riccardo

2010-08-01

154

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

International Nuclear Information System (INIS)

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

1994-01-01

155

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

International Nuclear Information System (INIS)

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

2007-01-01

156

Time-dependent changes of markers associated with inflammation in the lungs of humans exposed to ambient levels of ozone  

Energy Technology Data Exchange (ETDEWEB)

Acute exposure of humans to 0.4 ppm ozone results in reversible respiratory function decrements, and cellular and biochemical changes leading to the production of substances which can mediate inflammation and acute lung injury. While pulmonary function decrements occur almost immediately after ozone exposure, it is not known how quickly the cellular and biochemical changes indicative of inflammation occur in humans. Changes in neutrophils and PGE2 have been observed in humans as early as 3 hr (28) and as late as 18 hr post exposure (19). The purpose of this study was to determine whether inflammatory changes occur relatively rapidly (within 1 hr) following exposure to ozone, or if the cascade of events which are initiated by ozone and lead to inflammation, take some time to develop. We exposed 10 healthy volunteers twice: once to filtered air and once to 0.4 ppm ozone. Each exposure lasted for 2 hr at an exercise level of 60 L/min, and bronchoalveolar lavage was performed 1 hr following exposure. The data from this study were compared to those from a previous study in which 10 subjects were exposed to O3 under identical conditions except that bronchoalveolar lavage was performed 18 hr following exposure. The results of the present study demonstrate that O3 is capable of inducing rapid cellular and biochemical changes in the lung. These changes were detectable as early as 1 hr following a 2 hr exposure of humans to ozone. The profiles of these changes were different at 1 hr and 18 hr following ozone exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

Koren, H.S.; Devlin, R.B.; Becker, S.; Perez, R.; McDonnell, W.F. (Health Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC (United States))

1991-01-01

157

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

International Nuclear Information System (INIS)

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

2011-01-01

158

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

Energy Technology Data Exchange (ETDEWEB)

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

Ji Meng; Bell, Michelle L [School of Forestry and Environmental Studies, School of Public Health, Yale University, New Haven, CT (United States); Cohan, Daniel S [Department of Civil and Environmental Engineering, Rice University, Houston, TX (United States)

2011-04-15

159

Frequency of patients with acute asthma in relation to ozone, nitrogen dioxide, other pollutants of ambient air and meteorological observations.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To study the association of the daily frequency of registration of patients with acute asthma at the emergency department of a central hospital in the south-west of Sweden with levels of air pollution and meteorological observations. METHODS: A retrospective longitudinal study was made of asthma patients taken from a hospital registry. This information was correlated with measurements of ozone, nitrogen dioxide, sulphur dioxide, toluene, temperature and relative humidity. Patients were from the catchment area of the Central Hospital of Halmstad containing around 120,000 inhabitants. A total of 4127 visits of patients with acute asthma to the emergency department at the Central Hospital of Halmstad were registered during a period of 1247 days from January 1990 to May 1993. The differential optical absorption spectroscopy (DOAS) technique was used to monitor levels of air pollutants over a distance of 1000 m in the central part of the town of Halmstad. Data on temperature, relative humidity, precipitation, wind speed and wind direction for the time period were supplied by the Swedish Meteorological and Hydrological Institute (SMHI). RESULTS: There were many statistically significant correlations between the levels of air pollutants and the meteorological measurements and a strong negative correlation between ozone and nitrogen dioxide. There was a statistically significant effect on asthma visits in children of low temperature and high nitrogen dioxide levels, and on asthma visits in adults of high temperature and high levels of ozone. CONCLUSIONS: There was a different reaction pattern in children and adults with asthma regarding temperature and ozone/nitrogen dioxide. The strong correlations between temperature and air pollution and between the levels of ozone and nitrogen dioxide made the true relation between asthma, air pollution and temperature hard to evaluate statistically.

Holmén A; Blomqvist J; Frindberg H; Johnelius Y; Eriksson NE; Henricson KA; Herrström P; Högstedt B

1997-01-01

160

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)

1999-01-01

 
 
 
 
161

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-08-01

162

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

163

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

UK PubMed Central (United Kingdom)

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).

Sarkar A; Agrawal SB

2012-03-01

164

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

2011-07-23

165

High ambient ammonia promotes growth in a ureogenic goby, Mugilogobius abei.  

UK PubMed Central (United Kingdom)

Mugilogobius abei has the ability to produce large amounts of urea when exposed to high ambient ammonia. Despite this metabolically costly approach, and reports of growth inhibition effects of ammonia on fish, M. abei exposed to ammonia shows no adverse effects on growth. To investigate this observation the growth of M. abei was measured at room temperatures for 8 weeks at a constant ration level under solitary and grouped conditions, in 20% SW with or without (control) 2 mM NH(4)Cl. Furthermore, pituitary mRNA levels of growth hormone, oxygen consumption, incorporation of external (15)N-ammonia into amino acid and protein fractions as well as behavioral activities were also examined. The specific growth rates of ammonia-exposed fish under grouped condition over the 8 weeks were significantly higher than those of control, while those rates under solitary condition were not significantly different between the treatments. The pituitary of ammonia-exposed fish had higher growth hormone mRNA than in control fish. The use of (15)N isotope revealed that M. abei can actively use external ammonia as a supplementary nitrogen source. Oxygen consumption of ammonia-exposed fish was significantly lower than that of control fish. Locomotor activity and aggressive behavior under grouped condition were significantly reduced in ammonia-exposed fish as compared to those of control. These combined alterations in the ammonia-exposed fish may result in the higher growth rates.

Iwata K; Sakamoto T; Iwata I; Nishiguchi E; Kajimura M

2005-08-01

166

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

International Nuclear Information System (INIS)

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

2005-01-01

167

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

Energy Technology Data Exchange (ETDEWEB)

Estimates of increases in future agricultural production in response to increases in carbon dioxide (CO{sub 2}) concentrations in the atmosphere are often based on the beneficial physiological effect of CO{sub 2} enrichment on plant growth, especially in C{sub 3} plants. However, these estimates fail to consider the negative impact of ozone (O{sub 3}) air pollution on crop production. Increases in tropospheric concentrations of both gases, CO{sub 2} and O{sub 3}, have been observed over the past century, and both are predicted to continue to increase at even higher rates in the near future to levels when they may have a significant impact on agricultural production. Field studies with wheat (Triticum aestivum L.) in 1991 and 1992, and corn (Zea mays L.) in 1991 were conducted using open-top chambers to mimic atmospheric concentrations of CO{sub 2} ({approximately} 500 {micro}L{sup {minus}1} CO{sub 2}) and O{sub 3} ({approximately} 40 nL L{sup {minus}1} O{sub 3} above ambient air [O{sub 3}] during 7 h day{sup {minus}1}, 5 days week{sup {minus}1}) that are predicted to occur at the Earth`s surface during the first half of the 21st century. Wheat and corn (C{sub 3} vs. C{sub 4}) produced clearly different responses to CO{sub 2} enrichment, but similar responses to O{sub 3} exposure. In what, O{sub 3} exposure led to reduced grain yield, biomass, and radiation use efficiency (RUE, phytomass production per unit of energy received); in both years; but reduction in accumulated absorbed photosynthetically active radiation (AAPAR) was observed only in 1991. Conversely, CO{sub 2} enrichment produced greater grain yield, dry biomass, and RUE.

Rudorff, B.F.T. [National Inst. for Space Research, Sao Jose dos Campos (Brazil). Div. of Remote Sensing; Mulchi, C.L. [Univ. of Maryland, College Park, MD (United States). Dept. of Agronomy; Daughtry, C.S.T.; Lee, E.H. [Agricultural Research Service, Beltsville, MD (United States). Climate Stress Lab.

1996-02-01

168

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

International Nuclear Information System (INIS)

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

2003-01-01

169

A multi-variate statistical model integrating passive sampler and meteorology data to predict the frequency distributions of hourly ambient ozone (O{sub 3}) concentrations  

Energy Technology Data Exchange (ETDEWEB)

A statistical approach is described coupling passive ozone (O{sub 3}) sampler data with climatological variables to mimic the frequency distributions of hourly ambient O{sub 3} concentrations obtained by continuous monitoring. - A multi-variate, non-linear statistical model is described to simulate passive O{sub 3} sampler data to mimic the hourly frequency distributions of continuous measurements using climatologic O{sub 3} indicators and passive sampler measurements. The main meteorological parameters identified by the model were, air temperature, relative humidity, solar radiation and wind speed, although other parameters were also considered. Together, air temperature, relative humidity and passive sampler data by themselves could explain 62.5-67.5% (R{sup 2}) of the corresponding variability of the continuously measured O{sub 3} data. The final correlation coefficients (r) between the predicted hourly O{sub 3} concentrations from the passive sampler data and the true, continuous measurements were 0.819-0.854, with an accuracy of 92-94% for the predictive capability. With the addition of soil moisture data, the model can lead to the first order approximation of atmospheric O{sub 3} flux and plant stomatal uptake. Additionally, if such data are coupled to multi-point plant response measurements, meaningful cause-effect relationships can be derived in the future.

Krupa, S.; Nosal, M.; Ferdinand, J.A.; Stevenson, R.E.; Skelly, J.M

2003-07-01

170

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 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)

2001-01-01

171

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

2011-01-01

172

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.

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

2011-01-01

173

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

UK PubMed Central (United Kingdom)

The northern hemisphere temperate and boreal forests currently provide an important carbon sink; however, current tropospheric ozone concentrations ([O?]) and [O?] projected for later this century are damaging to trees and have the potential to reduce the carbon sink strength of these forests. This meta-analysis estimated the magnitude of the impacts of current [O?] and future [O?] on the biomass, growth, physiology and biochemistry of trees representative of northern hemisphere forests. Current ambient [O?] (40 ppb on average) significantly reduced the total biomass of trees by 7% compared with trees grown in charcoal-filtered (CF) controls, which approximate preindustrial [O?]. Above- and belowground productivity were equally affected by ambient [O?] in these studies. Elevated [O?] of 64 ppb reduced total biomass by 11% compared with trees grown at ambient [O?] while elevated [O?] of 97 ppb reduced total biomass of trees by 17% compared with CF controls. The root-to-shoot ratio was significantly reduced by elevated [O?] indicating greater sensitivity of root biomass to [O?]. At elevated [O?], trees had significant reductions in leaf area, Rubisco content and chlorophyll content which may underlie significant reductions in photosynthetic capacity. Trees also had lower transpiration rates, and were shorter in height and had reduced diameter when grown at elevated [O?]. Further, at elevated [O?], gymnosperms were significantly less sensitive than angiosperms. There were too few observations of the interaction of [O?] with elevated [CO?] and drought to conclusively project how these climate change factors will alter tree responses to [O?]. Taken together, these results demonstrate that the carbon-sink strength of northern hemisphere forests is likely reduced by current [O?] and will be further reduced in future if [O?] rises. This implies that a key carbon sink currently offsetting a significant portion of global fossil fuel CO? emissions could be diminished or lost in the future.

Wittig VictoriaE; Ainsworth ElizabethA; Naidu ShawnaL; Karnosky DavidF; Long StephenP

2009-02-01

174

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1980-01-01

175

Use of ethylene diurea (EDU) in assessing the impact of ozone on growth and productivity of five cultivars of Indian wheat (Triticum aestivum L.).  

UK PubMed Central (United Kingdom)

Increase in concentrations of tropospheric ozone (O(3)) is one of the main factors affecting world agriculture production. Tropical countries including India are at greater risk due to their meteorological conditions (high solar radiation and temperature) being conducive to the formation of O(3). The most effective anti-ozonant chemical is N-[2-(2-oxo-1-imidazolidinyl) ethyl]-N-phenylurea or ethylene diurea (EDU). Due to its specific characteristics, EDU has been used in the field as a phytomonitoring agent to assess crop losses due to O(3). Field experiments were conducted on five local cultivars of wheat (Triticum aestivum L. cv HUW234, HUW468, HUW510, PBW343, and Sonalika) grown under natural field conditions in a suburban area of Varanasi, Uttar Pradesh, India during December 2006 to March 2007 to determine the impact of O(3) on their growth and yield characteristics. Mean monthly O(3) concentrations varied between 35.3 ppb and 54.2 ppb at the experimental site. EDU treatment positively affected various growth and yield parameters with difference between cultivars. EDU-treated plants showed increase in shoot and root length, leaf area, absolute growth rate, relative growth rate, and net primary productivity, indicating O(3) induced suppression in growth. EDU treatment was highly significant in different cultivars for total biomass and test weight but not for harvest index. Yield per plant was higher by 25.6%, 24%, 20.4%, 8.6%, and 1.9% in EDU-treated cultivars HUW468, Sonalika, HUW510, HUW234, and PBW343, respectively, than non-EDU-treated ones. These results clearly indicate the sensitivity of all the wheat cultivars to ambient levels of O(3) with cv HUW468 appearing to be most sensitive. The present study also supports the view that EDU has great potential in alleviating the unfavorable effects of O(3) and can be effectively used as a monitoring tool to assess growth and yield losses in areas experiencing elevated concentrations of O(3).

Singh S; Agrawal SB

2009-12-01

176

Effects of varying environmental conditions on vegetation response to ozone exposure  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-12-31

177

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

Energy Technology Data Exchange (ETDEWEB)

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

Mainiero, Raphael, E-mail: raphael.mainiero@iap.c [Department for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Kazda, Marian, E-mail: marian.kazda@uni-ulm.d [Department for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Haeberle, Karl-Heinz, E-mail: haeberle@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany); Nikolova, Petia Simeonova, E-mail: nikolova@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany); Matyssek, Rainer, E-mail: matyssek@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany)

2009-10-15

178

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

Energy Technology Data Exchange (ETDEWEB)

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

Grandjean, A.; Fuhrer, J.

1987-08-01

179

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

Science.gov (United States)

Plant functional type (PFT) distributions affect the results of biogenic emission modeling as well as O3 and PM simulations using chemistry-transport models (CTMs). This paper analyzes the variations of both surface biogenic VOC emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. Also, this paper attempts to provide important implications for biogenic emissions modeling studies for CTM simulations. MM5-MEGAN-SMOKE-CMAQ model simulations were implemented over the Seoul Metropolitan Areas in Korea to predict surface O3 concentrations for the period of 1 May to 31 June 2008. Starting from MEGAN biogenic emissions analysis with three different sources of PFT input data, US EPA CMAQ O3 simulation results were evaluated by surface O3 monitoring datasets and further considered on the basis of geospatial and statistical analyses. The three PFT datasets considered were "(1)KORPFT", developed with a region specific vegetation database; (2) CDP, adopted from US NCAR; and (3) MODIS, reclassified from the NASA Terra and Aqua combined land cover products. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BT) are the most significant contributor, followed by needleleaf trees (NT), shrub (SB), and herbaceous plants (HB) to the total biogenic volatile organic compounds (BVOCs). In addition, isoprene from BT and terpene from NT were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. Multiple regression analyses with the different PFT data (?O3 vs. ?PFTs) suggest that KORPFT can provide reasonable information to the framework of MEGAN biogenic emissions modeling and CTM O3 predictions. Analyses of the CMAQ performance statistics suggest that deviations of BT areas can significantly affect CMAQ isoprene and O3 predictions. From further evaluations of the isoprene and O3 prediction results, we explored the PFT area-loss artifact that occurs due to geographical disparity between the PFT and leaf area index distributions, and can cause increased bias in CMAQ O3. Thus, the PFT-loss artifact must be a source of limitation in the MEGAN biogenic emission modeling and the CTM O3 simulation results. Time changes of CMAQ O3 distributions with the different PFT scenarios suggest that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 10 ppb. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of representative PFT distributions becomes more critical for O3 air quality modeling (or forecasting) in support of air quality decision-making and human health studies.

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

2013-09-01

180

Ambient fine particulate matter and ozone exposures induce inflammation in epicardial and perirenal adipose tissues in rats fed a high fructose diet.  

UK PubMed Central (United Kingdom)

BACKGROUND: Inflammation and oxidative stress play critical roles in the pathogenesis of inhaled air pollutant-mediated metabolic disease. Inflammation in the adipose tissues niches are widely believed to exert important effects on organ dysfunction. Recent data from both human and animal models suggest a role for inflammation and oxidative stress in epicardial adipose tissue (EAT) as a risk factor for the development of cardiovascular disease. We hypothesized that inhalational exposure to concentrated ambient fine particulates (CAPs) and ozone (O3) exaggerates inflammation and oxidative stress in EAT and perirenal adipose tissue (PAT). METHODS: Eight- week-old Male Sprague--Dawley rats were fed a normal diet (ND) or high fructose diet (HFr) for 8 weeks, and then exposed to ambient AIR, CAPs at a mean of 356 mug/m3, O3 at 0.485 ppm, or CAPs (441 mug/m3) + O3 (0.497 ppm) in Dearborn, MI, 8 hours/day, 5 days/week, for 9 days over 2 weeks. RESULTS: EAT and PAT showed whitish color in gross, and less mitochondria, higher mRNA expression of white adipose specific and lower brown adipose specific genes than in brown adipose tissues. Exposure to CAPs and O3 resulted in the increase of macrophage infiltration in both EAT and PAT of HFr groups. Proinflammatory genes of Tnf-alpha, Mcp-1 and leptin were significantly upregulated while IL-10 and adiponectin, known as antiinflammatory genes, were reduced after the exposures. CAPs and O3 exposures also induced an increase in inducible nitric oxide synthase (iNOS) protein expression, and decrease in mitochondrial area in EAT and PAT. We also found significant increases in macrophages of HFr-O3 rats. The synergetic interaction of HFr and dirty air exposure on the inflammation was found in most of the experiments. Surprisingly, exposure to CAPs or O3 induced more significant inflammation and oxidative stress than co-exposure of CAPs and O3 in EAT and PAT. CONCLUSION: EAT and PAT are both white adipose tissues. Short-term exposure to CAPs and O3, especially with high fructose diet, induced inflammation and oxidative stress in EAT and PAT in rats. These findings may provide a link between air-pollution exposure and accelerated susceptibility to cardiovascular disease and metabolic complications.

Sun L; Liu C; Xu X; Ying Z; Maiseyeu A; Wang A; Allen K; Lewandowski RP; Bramble LA; Morishita M; Wagner JG; Dvonch JT; Sun Z; Yan X; Brook RD; Rajagopalan S; Harkema JR; Sun Q; Fan Z

2013-08-01

 
 
 
 
181

Ambient fine particulate matter and ozone exposures induce inflammation in epicardial and perirenal adipose tissues in rats fed a high fructose diet  

Science.gov (United States)

Background Inflammation and oxidative stress play critical roles in the pathogenesis of inhaled air pollutant-mediated metabolic disease. Inflammation in the adipose tissues niches are widely believed to exert important effects on organ dysfunction. Recent data from both human and animal models suggest a role for inflammation and oxidative stress in epicardial adipose tissue (EAT) as a risk factor for the development of cardiovascular disease. We hypothesized that inhalational exposure to concentrated ambient fine particulates (CAPs) and ozone (O3) exaggerates inflammation and oxidative stress in EAT and perirenal adipose tissue (PAT). Methods Eight- week-old Male Sprague–Dawley rats were fed a normal diet (ND) or high fructose diet (HFr) for 8 weeks, and then exposed to ambient AIR, CAPs at a mean of 356 ?g/m3, O3 at 0.485 ppm, or CAPs (441 ?g/m3)?+?O3 (0.497 ppm) in Dearborn, MI, 8 hours/day, 5 days/week, for 9 days over 2 weeks. Results EAT and PAT showed whitish color in gross, and less mitochondria, higher mRNA expression of white adipose specific and lower brown adipose specific genes than in brown adipose tissues. Exposure to CAPs and O3 resulted in the increase of macrophage infiltration in both EAT and PAT of HFr groups. Proinflammatory genes of Tnf-?, Mcp-1 and leptin were significantly upregulated while IL-10 and adiponectin, known as antiinflammatory genes, were reduced after the exposures. CAPs and O3 exposures also induced an increase in inducible nitric oxide synthase (iNOS) protein expression, and decrease in mitochondrial area in EAT and PAT. We also found significant increases in macrophages of HFr-O3 rats. The synergetic interaction of HFr and dirty air exposure on the inflammation was found in most of the experiments. Surprisingly, exposure to CAPs or O3 induced more significant inflammation and oxidative stress than co-exposure of CAPs and O3 in EAT and PAT. Conclusion EAT and PAT are both white adipose tissues. Short-term exposure to CAPs and O3, especially with high fructose diet, induced inflammation and oxidative stress in EAT and PAT in rats. These findings may provide a link between air-pollution exposure and accelerated susceptibility to cardiovascular disease and metabolic complications.

2013-01-01

182

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

183

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

Energy Technology Data Exchange (ETDEWEB)

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

Bussotti, Filippo, E-mail: filippo.bussotti@unifi.i [Universita degli Studi di Firenze, Dipartimento di Biologia Vegetale, Piazzale delle Cascine 28, 50144 Firenze (Italy); Ferretti, Marco [TerraData environmetrics, Dipartimento di Scienze Ambientali, Universita di Siena (Italy)

2009-05-15

184

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

International Nuclear Information System (INIS)

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

2006-01-01

185

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

Science.gov (United States)

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. PMID:16290915

Bender, J; Muntifering, R B; Lin, J C; Weigel, H J

2005-11-15

186

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

187

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.

2006-01-01

188

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

Scientific Electronic Library Online (English)

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

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

2008-04-01

189

Sensitivity of photosynthesis and stomatal conductance in mature beech (Fagus sylvatica L.) to ambient or experimentally enhanced ozone regimes Empfindlichkeit der Photosynthese und stomatären Leitfähigkeit adulter Buchen (Fagus sylvatica L.) gegenüber natürlichen und experimentell erhöhten Ozon-Regimen  

Digital Repository Infrastructure Vision for European Research (DRIVER)

During the years 2003 and 2004, the influence of experimentally enhanced ozone concentrations (by means of “free-air" fumigation) on the photosynthetic rate and stomatal conductance of 60-year-old beech trees was examined and compared to control trees of same age growing under unchanged ozone concen...

Löw, Markus

190

Ethylene reduces plant gas exchange and growth of lettuce grown from seed to harvest under hypobaric and ambient total pressure.  

UK PubMed Central (United Kingdom)

Naturally occurring high levels of ethylene can be a problem in spaceflight and controlled environment agriculture (CEA) leading to sterility and irregular plant growth. There are engineering and safety advantages of growing plants under hypobaria (low pressure) for space habitation. The goals of this research were to successfully grow lettuce (Lactuca sativa cv. Buttercrunch) in a long-term study from seed to harvest under hypobaric conditions, and to investigate how endogenously produced ethylene affects gas exchange and plant growth from seed germination to harvest under hypobaric and ambient total pressure conditions. Lettuce was grown under two levels of total gas pressure [hypobaric or ambient (25 or 101 kPa)] in a long-term, 32-day study. Significant levels of endogenous ethylene occurred by day-15 causing reductions in photosynthesis, dark-period respiration, and a subsequent decrease in plant growth. Hypobaria did not mitigate the adverse ethylene effects on plant growth. Seed germination was not adversely affected by hypobaria, but was reduced by hypoxia (6 kPa pO(2)). Under hypoxia, seed germination was higher under hypobaria than ambient total pressure. This research shows that lettuce can be grown from seed to harvest under hypobaria (?25% of normal earth ambient total pressure).

He C; Davies FT Jr

2012-03-01

191

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

192

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

UK PubMed Central (United Kingdom)

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

Bussotti F; Ferretti M

2009-05-01

193

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

Science.gov (United States)

The impact of ozone on forest ecosystems in Italy is monitored within the CONECOFOR programme. Ozone levels are measured in 30 plots using passive samplers. Response parameters used are: crown condition (transparency), BAI (basal area increment), and visible symptoms on spontaneous vegetation. Levels of AOT40 are above the concentration-based critical level of 5 ppm h in all sites, but the evidence of impact on forest vegetation remains limited. Ozone is a predictor of crown transparency residuals in beech sites over two consecutive years, but the variance explained amounts to less than 10%. The relation between BAI reduction and ozone is even less certain. Transparency and BAI are more readily explainable in terms of ecological conditions of the site and climate fluctuations. The interpretation of visible symptoms is doubtful, and is conditioned by the prevailing ecological factors in the areas. PMID:18977569

Bussotti, Filippo; Ferretti, Marco

2008-11-01

194

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

195

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

International Nuclear Information System (INIS)

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

2008-01-01

196

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

UK PubMed Central (United Kingdom)

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

Aïdam A; Michel CL; Bonnet X

2013-07-01

197

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

Science.gov (United States)

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

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

2013-04-11

198

Effects of ozone and acid rain on white pine (Pinus strobus) seedlings grown in five soils; 1. Net photosynthesis and growth  

Energy Technology Data Exchange (ETDEWEB)

Four replicated factorial experiments were conducted to assess the response of potted white pine (Pinus strobus L.) seedlings to combined acid rain, ozone, and soil treatments. The objectives of the study were to quantify plant response to each pollutant alone and to determine whether the pollutants and edaphic factors interact in affecting physiological processes in white pine. In these studies, seedlings were grown in five forest soils and exposed for 4 months to realistic levels of acid rain and ozone. Acid rain treatments consisted of exposure to simulated rain of pH 5.6, 4.0, 3.5, or 3.0, while ozone treatments consisted of exposure to 0.02, 0.06, 0.10, or 0.14 ppM ozone. Minimal interaction between acid rain and ozone was observed with regard to photosynthesis or growth. Acid rain and soil type had a strong interaction in determining plant response. In general, acid rain caused increased growth and net photosynthesis as a result of nitrogen fertilization from the simulated rain. However, the extent of this response was inversely correlated with the availability of nitrogen in each soil. Ozone treatments caused decreased net photosynthesis in pine seedlings. 26 refs., 5 figs., 6 tabs.

Reich, P.B.; Schoettle, A.W.; Stroo, H.F.; Troiano, J.; Amundson, R.G. (Cornell Univ., Ithaca, NY (USA))

1987-01-01

199

Measurement of Ozone Production Sensor  

Directory of Open Access Journals (Sweden)

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

M. Cazorla; W. H. Brune

2010-01-01

200

Measurement of ozone production sensor  

Directory of Open Access Journals (Sweden)

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

M. Cazorla; W. H. Brune

2009-01-01

 
 
 
 
201

78 FR 32135 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...  

Science.gov (United States)

...Plans; Atlanta, Georgia 1997 8-Hour Ozone Nonattainment Area; Reasonable Further...for the Atlanta, Georgia 1997 8-hour ozone national ambient air quality standards...area. The Atlanta, Georgia 1997 8-hour ozone nonattainment area (hereafter...

2013-05-29

202

77 FR 73570 - Approval and Promulgation of Implementation Plans; New Jersey and New York Ozone Attainment...  

Science.gov (United States)

...Implementation Plans; New Jersey and New York Ozone Attainment Demonstrations AGENCY: Environmental...Agency (EPA) is proposing action on the ozone attainment demonstration portion of comprehensive...requirements for attaining the 1997 8-hour ozone national ambient air quality...

2012-12-11

203

78 FR 27161 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Ozone Attainment...  

Science.gov (United States)

...Quality Implementation Plans; Connecticut; Ozone Attainment Demonstrations AGENCY: Environmental...SUMMARY: EPA is proposing to approve the ozone attainment demonstrations (including the...requirements for attaining the 1997 8-hour ozone national ambient air quality...

2013-05-09

204

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.

1992-01-01

205

Evaluating a heated metal scrubber's effectiveness in preventing ozone monitors' anomalous behavior during hot and humid ambient sampling  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to verify West Virginia's Wet/Dry test's prediction that Advanced Pollution Instrumentation's (API) ozone monitors, when using a heated metal scrubber in lieu of a standard MnO{sub 2} scrubber, would be made insensitive to sampling conditions which provoke anomalous behavior. Field trials involving two identical API model 400 ozone monitors, a Horiba APOA 360 ozone monitor, MnO{sub 2} scrubbers and API's optional heated metal scrubber would determine this. The heated metal scrubber succeeded in effectively eliminating the anomalous behavior. Evaluation results further verify the accuracy of West Virginia's Wet/Dry test. During the evaluation, a serendipitous event led to observations that confirmed previous observations by The Commonwealth of Virginia's monitoring staff, linking contamination of UV monitors' optics with anomalous behavior. Also, a partial summation of observations concerning ultraviolet ozone monitors' anomalous behavior, drawn from several sources, illustrates its complex nature.

Maddy, J.A.

1999-07-01

206

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

2013-09-26

207

Ozone Exposure of a Weed Community Produces Adaptive Changes in Seed Populations of Spergula arvensis.  

UK PubMed Central (United Kingdom)

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.

Landesmann JB; Gundel PE; Martínez-Ghersa MA; Ghersa CM

2013-01-01

208

Urban ozone and its precursors  

Energy Technology Data Exchange (ETDEWEB)

This article addresses the ozone problems of urban areas, emphasizing three important issues. The first concerns the form and level of the National Ambient Air Quality Standard (NAAQS), which directly affects the achievability of the standard,as well as confidence in its attainment. The second issue encompasses the trend in ozone concentrations, which is a measure of the effectiveness of existing ozone control strategies. The third entails the control strategies whose failure may reflect a deficiency in the understanding of the ozone problem or in the implementation of the strategies themselves.

Chock, D.P.; Heuss, J.M.

1987-12-01

209

Final report on the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with ISCIII (December 2012)  

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 Instituto de Salud Carlos III (ISCIII) 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; Morillo Gomez, Pilar; Sánchez, Carmen

2013-01-01

210

Growth and survival of Escherichia coli O157:H7 in fresh tropical fruit juices at ambient and cold temperatures.  

UK PubMed Central (United Kingdom)

The survival of Escherichia coli O157:H7 in acidic foods and its enhanced survival in refrigerated acid foods are well documented. This prompted the present study to evaluate the growth potential of E. coli O157:H7 in fresh tropical fruit juices. The pH of the various juices ranged between 3.57 (pineapple) and 6.2 (avocado). Samples were separately inoculated with a mixture of four E. coli O157:H7 strains at initial levels of approximately 10(3) cfu/ml, and stored at refrigeration (4 degrees C) and ambient (20-25 degrees C) temperatures for 120 h. In pineapple juice, some decline in count was noted during ambient temperature storage but complete inhibition was not observed. At refrigeration temperature, the test strains survived without a noticeable decline in number. The pH remained unchanged throughout the experiment at both incubation temperatures. In papaya and avocado juices, counts of the test strains increased at varying rates at both storage temperatures. A decrease in pH was also noted in the stored juice. This study demonstrated that E. coli O157:H7 can survive well in acidic pineapple juice at both incubation temperatures and could also grow luxuriously in fruit juices with relatively higher pH values (>5.7) when stored at ambient and refrigeration temperatures.

Mutaku I; Erku W; Ashenafi M

2005-03-01

211

Photoprotection, photosynthesis and growth of tropical tree seedlings under near-ambient and strongly reduced solar ultraviolet-B radiation.  

Science.gov (United States)

Seedlings of two late-successional tropical rainforest tree species, Tetragastris panamensis (Engler) O. Kuntze and Calophyllum longifolium (Willd.), were field grown for 3-4 months at an open site near Panama City (9 degrees N), Panama, under plastic films that either transmitted or excluded most solar UV-B radiation. Experiments were designed to test whether leaves developing under bright sunlight with strongly reduced UV-B are capable of acclimating to near-ambient UV-B conditions. Leaves of T. panamensis that developed under near-ambient UV-B contained higher amounts of UV-absorbing substances than leaves of seedlings grown under reduced UV-B. Photosynthetic pigment composition, content of alpha-tocopherol, CO(2) assimilation, potential photosystem II (PSII) efficiency (evaluated by F(v)/F(m) ratios) and growth of T. panamensis and C. longifolium did not differ between seedlings developed under near-ambient and reduced solar UV-B. When seedlings were transferred from the reduced UV-B treatment to the near-ambient UV-B treatment, a pronounced inhibition of photosynthetic capacity was observed initially in both species. UV-B-mediated inhibition of photosynthetic capacity nearly fully recovered within 1 week of the transfer in C. longifolium, whereas in T. panamensis an about 35% reduced capacity of CO(2) uptake was maintained. A marked increase in UV-absorbing substances was observed in foliage of transferred T. panamensis seedlings. Both species exhibited enhanced mid-day photoinhibition of PSII immediately after being transferred from the reduced UV-B to the near-ambient UV-B treatment. This effect was fully reversible within 1d in T. panamensis and within a few days in C. longifolium. The data show that leaves of these tropical tree seedlings, when developing in full-spectrum sunlight, are effectively protected against high solar UV-B radiation. In contrast, leaves developing under conditions of low UV-B lacked sufficient UV protection. They experienced a decline in photosynthetic competence when suddenly exposed to near-ambient UV-B levels, but exhibited pronounced acclimative responses. PMID:17074417

Krause, G Heinrich; Jahns, Peter; Virgo, Aurelio; García, Milton; Aranda, Jorge; Wellmann, Eckard; Winter, Klaus

2006-10-30

212

Corona Discharge Influences Ozone Concentrations Near Rats  

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-02-26

213

Ozone Pollution  

Medline Plus

Full Text Available ... to reduce ozone. Who is at risk from breathing ozone? Five groups of people are especially vulnerable to the effects of breathing ozone: children and teens; anyone 65 and older; ...

214

Ozone Pollution  

Medline Plus

Full Text Available ... Report Or Or Enter Your Zip Code: Ozone Pollution It may be hard to imagine that pollution ... flag system on the beach. 22 How Ozone Pollution Harms Your Health Breathing ozone can shorten your ...

215

Ozone Pollution  

Medline Plus

Full Text Available ... we want to reduce ozone. Who is at risk from breathing ozone? Five groups of people are ... depend on many factors, however. For example, the risks would be greater if ozone levels are higher, ...

216

Ozone Pollution  

Science.gov (United States)

... Report Or Or Enter Your Zip Code: Ozone Pollution It may be hard to imagine that pollution ... flag system on the beach. 22 How Ozone Pollution Harms Your Health Breathing ozone can shorten your ...

217

Ozone Pollution  

Medline Plus

Full Text Available ... of ozone on health for decades. Hundreds of research studies have confirmed that ozone harms people at ... when ozone levels were high. Because of this research, Galveston became the first city in the nation ...

218

Ozone Pollution  

Medline Plus

Full Text Available ... Download Report Or Or Enter Your Zip Code: Ozone Pollution It may be hard to imagine that ... Flash Player to see this player. What Is Ozone? Ozone (O 3 ) is an extremely reactive gas ...

219

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.).

1994-01-01

220

Effects of tropospheric ozone on methane and carbon dioxide fluxes from peatland mesocosms  

Science.gov (United States)

Tropospheric ozone is currently the third most important greenhouse gas, and also the most important gaseous air pollutant globally in terms of effects on vegetation world-wide. At present levels it poses a significant threat to crop yield and forest productivity of sensitive species, while background ozone concentrations are expected to increase further during the next decades. The potential importance of ozone in reducing carbon assimilation, and consequently in increasing atmospheric carbon dioxide concentrations, has been recognised. However, regional modelling studies are based on the impact of ozone on photosynthetic rates and above-ground growth, and do not consider effects of ozone on belowground carbon fluxes. The limited experimental data on the long-term effects of ozone on belowground carbon processes, mainly from arable crop and forest systems, are a major constraint to understanding the impacts of ozone on global carbon fluxes. Very little attention has been paid to ozone effects on peatland carbon dynamics, though northern peatlands store a third of the global soil organic carbon pool and are an important source of atmospheric methane. The aims of this study were to assess the long-term effects of elevated ozone on carbon dioxide and methane fluxes in temperate peatland mesocosms and to identify underlying plant, soil and microbial processes. Mesocosms from a wet heath (Isle of Skye, UK) with vegetation dominated by the peat moss Sphagnum papillosum and the sedge Schoenus nigricans have been exposed to ambient (control) and three elevated levels of ozone in open-top chambers from May 2008. Methane emission, carbon dioxide fluxes and relevant plant and soil variables were measured every 6 weeks (growing season) or 8 weeks (winter). Methane emissions were significantly reduced by elevated ozone over the first 18 months of the experiment. Ecosystem respiration only showed a significant increase in response to ozone in the second growing season, while gross photosynthesis has been enhanced by elevated ozone up till now. The latter may partly be explained by higher net biomass Sphagnum production observed at elevated ozone. Leaf biomass and stomatal conductance of Schoenus nigricans were not affected by ozone. Additional soil and plant data will be presented that may help unravel the mechanisms underling the observed changes in greenhouse gas fluxes. Hence, the results imply that increases in global background ozone concentrations that are predicted by models in the northern hemisphere over the 21st century may lead to a negative feedback on methane emissions from peatland ecosystems. This study will be continued with methane emission and high-frequency carbon dioxide flux measurements and more detailed process studies, including stable isotope tracer studies, providing key information for long-term predictions of ozone impacts on carbon dynamics in peatland ecosystems.

Toet, Sylvia; Oliver, Vikki; Helgason, Thorunn; Peacock, Simon; Barnes, Jeremy; Ineson, Phil; Ashmore, Mike

2010-05-01

 
 
 
 
221

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

International Nuclear Information System (INIS)

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

2009-01-01

222

Ground-level ozone in Alberta  

Energy Technology Data Exchange (ETDEWEB)

The goals of the study were to: identify agencies, industries and associations that are collecting data on ambient ozone and its precursors, NOX and VOC in Alberta, compile a list of report and papers from Alberta on ambient ozone, ozone precursors and related photochemical products starting from the year 1980, provide a literature review on all papers and reports produced for Alberta, review and assess the information compiled, relating Alberta information to the national scene wherever possible, and comparing ambient ozone levels in Alberta to the proposed reference levels and Canada wide standards options for ground-level ozone. Calgary and Edmonton as cities in Alberta mostly act as ozone sinks because of reactions with nitric oxide emitted from urban sources. These chemical reactions produce other secondary air pollutants like peroxyactyl nitrate, nitric acid and particulate nitrate. A good urban database on ambient ozone exists in Alberta. The information is reliable and well recognized in the international scientific literature. Considering the current Canadian and Alberta objectives of one-hour of maximum ozone concentration of 82 ppb, there are no concerns about meeting this objective in Alberta cities except a few which surpassed the level during the last five years. Rural values of ozone concentrations are high compared with urban centres. The 24-hour Alberta objective for ozone is exceeded most of the time in rural Alberta compared with major cities.

Sandhu, H.S. [Atmospheric Science and Management Associates, Edmonton, AB (Canada)

1999-04-01

223

The adverse effect of low levels of ambient air pollutants on lung function growth in preadolescent children.  

Science.gov (United States)

The main purpose of our study was to assess the effect of low concentrations of ambient air pollution on lung function growth in preadolescent children. We accounted for height velocity over the follow-up period and also for other possible confounders such as baseline anthropometric and physiologic characteristics of children. In addition to outdoor air pollution, we considered the possible effects of social class and exposure to indoor pollutants such as gas stove fumes or environmental tobacco smoke. The cohort prospective study was carried out in 1,001 preadolescent children from two areas of Krakow, Poland, that differed in ambient air pollutants. In the city center (higher pollution area), the mean annual level [+/- standard deviation (SD)] of suspended particulate matter was 52.6 +/- 53.98 microg/m(3) and that of SO(2) was 43.87 +/- 32.69 microg/m(3); the corresponding values in the control area were 33.23 +/- 35.99 microg/m(3) and 31.77 +/- 21.93 microg/m(3). Mean lung function growth rate adjusted to height velocity and lung function level at the study entry was significantly lower in boys and girls living in the more polluted areas. Also, the proportion of children with the slower lung function growth (SLFG) was higher in the children from the more polluted area of the city. The analysis completed in the group of children after the exclusion of asthmatic subjects and those with asthmalike symptoms confirmed that, in boys, odds ratios (ORs) for SLFG [forced vital capacity (FVC)] and air pollution after adjustment to baseline FVC, height, and growth rate was significant [OR = 2.15; 95% confidence interval (CI), 1.25-3. 69)]. The analysis also confirmed that for SLFG(FEV(1)) the OR was 1. 90 (CI, 1.12-3.25). The corresponding OR values in girls were insignificant (OR = 1.50; CI, 0.84-2.68 and OR = 1.39; CI, 0.78-2. 44). The association between ambient pollutants and poorer gain of pulmonary volumes in children living in more polluted areas suggests that air pollution in the residence area may be a part of the causal chain of reactions leading to retardation in pulmonary function growth during the preadolescent years. PMID:10417366

Jedrychowski, W; Flak, E; Mróz, E

1999-08-01

224

Biogenic growth of alloys and core-shell nanostructures using urease as a nanoreactor at ambient conditions.  

UK PubMed Central (United Kingdom)

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

Sharma B; Mandani S; Sarma TK

2013-09-01

225

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

Science.gov (United States)

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

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

2013-01-01

226

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

2013-09-10

227

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

International Nuclear Information System (INIS)

An assessment of the effects of tropospheric ozone (O3) 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 O3 and three N levels. Increased O3 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 O3-induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O3 limits for the protection of herbaceous vegetation. - Research highlights: ? Forage quality (foliar protein and fiber content) and phenology are more O3-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 O3-induced increase in senescence biomass. ? Nutritive quality and phenology should be considered in new definitions of the O3 limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O3-sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

2011-01-01

228

Effects of ozone and sulfur dioxide on processing tomato yields and quality. Final report  

Energy Technology Data Exchange (ETDEWEB)

The object of the experiment was to study the effects of SO/sub 2/ and/or ozone on tomato vegetative growth, fruit yields, and fruit quality. Two varieties of processing tomatoes, UC-204-B and E-6203, were exposed to four levels of ozone and two levels of SO/sub 2/. Exposure to ambient ozone caused a 20% reduction in vine weights and 27% reduction in weight of red fruit compared to filtered air. Exposure to 0.1 ppm SO/sub 2/ produced 7% fewer vines and approximately 8% less fruit as compared with no SO/sub 2/ exposure. Fruit quality tests indicated that increasing ozone levels reduce soluble solids (Brix), and they reduce viscosity, an important indicator of processing behavior. Exposure to SO/sub 2/ in the concentrations used increased total solids but had no measurable effect on viscosity or consistency.

Brewer, R.F.

1986-03-01

229

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

UK PubMed Central (United Kingdom)

A field experiment was conducted under tropical climate for assessing the effect of ambient UV-B and UV-A by exclusion of UV components on the growth, photosynthetic performance and yield of C3 (cotton, wheat) and C4 (amaranthus, sorghum) plants. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (<315nm), UV-A+B (<400nm), transmitted all the UV (280-400nm) or without filters. All the four plant species responded to UV exclusion by a significant increase in plant height, leaf area, leaf biomass, total biomass accumulation and yield. Measurements of the chlorophyll, chlorophyll fluorescence parameters, gas exchange parameters and the activity of Ribulose-1,5-bisphosphate carboxylase (Rubisco) by fixation of (14)CO2 indicated a direct relationship between enhanced rate of photosynthesis and yield of the plants. Quantum yield of electron transport was enhanced by the exclusion of UV indicating better utilization of PAR assimilation and enhancement in reducing power in all the four plant species. Exclusion of UV-B in particular significantly enhanced the net photosynthetic rate, stomatal conductance and activity of Rubisco. Additional fixation of carbon due to exclusion of ambient UV-B was channeled towards yield as there was a decrease in the level of UV-B absorbing substances and an increase in soluble proteins in all the four plant species. The magnitude of the promotion in all the parameters studied was higher in dicots (cotton, amaranthus) compared to monocots (wheat, sorghum) after UV exclusion. The results indicated a suppressive action of ambient UV-B on growth and photosynthesis; dicots were more sensitive than monocots in this suppression while no great difference in sensitivity was found between C3 and C4 plants. Experiments indicated the suppressive action of ambient UV on carbon fixation and yield of C3 and C4 plants. Exclusion of solar UV-B will have agricultural benefits in both C3 and C4 plants under tropical climate.

Kataria S; Guruprasad KN; Ahuja S; Singh B

2013-08-01

230

Exposure-Relevant Ozone Chemistry in Occupied Spaces  

Energy Technology Data Exchange (ETDEWEB)

Ozone, an ambient pollutant, is transformed into other airborne pollutants in the indoor environment. In this dissertation, the type and amount of byproducts that result from ozone reactions with common indoor surfaces, surface residues, and vapors were determined, pollutant concentrations were related to occupant exposure, and frameworks were developed to predict byproduct concentrations under various indoor conditions. In Chapter 2, an analysis is presented of secondary organic aerosol formation from the reaction of ozone with gas-phase, terpene-containing consumer products in small chamber experiments under conditions relevant for residential and commercial buildings. The full particle size distribution was continuously monitored, and ultrafine and fine particle concentrations were in the range of 10 to>300 mu g m-3. Particle nucleation and growth dynamics were characterized.Chapter 3 presents an investigation of ozone reactions with aircraft cabin surfaces including carpet, seat fabric, plastics, and laundered and worn clothing fabric. Small chamber experiments were used to determine ozone deposition velocities, ozone reaction probabilities, byproduct emission rates, and byproduct yields for each surface category. The most commonly detected byproducts included C1?C10 saturated aldehydes and skin oil oxidation products. For all materials, emission rates were higher with ozone than without. Experimental results were used to predict byproduct exposure in the cabin and compare to other environments. Byproduct levels are predicted to be similar to ozone levels in the cabin, which have been found to be tens to low hundreds of ppb in the absence of an ozone converter. In Chapter 4, a model is presented that predicts ozone uptake by and byproduct emission from residual chemicals on surfaces. The effects of input parameters (residue surface concentration, ozone concentration, reactivity of the residue and the surface, near-surface airflow conditions, and byproduct yield) were explored. In Chapter 5, the reaction of ozone with permethrin, a residual insecticide used in aircraft cabins, to form phosgene is investigated. A derivatization technique was developed to detect phosgene at low levels, and chamber experiments were conducted with permethrin-coated cabin materials. It was determined that phosgene formation, if it occurs in the aircraft cabin, is not likely to exceed the relevant, health-based phosgene exposure guidelines.

Coleman, Beverly Kaye

2009-04-01

231

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

Science.gov (United States)

The hypothesis was tested that O(3)-induced changes in leaf-level photosynthetic parameters have the capacity of limiting the seasonal photosynthetic carbon gain of adult beech trees. To this end, canopy-level photosynthetic carbon gain and respiratory carbon loss were assessed in European beech (Fagus sylvatica) by using a physiologically based model, integrating environmental and photosynthetic parameters. The latter were derived from leaves at various canopy positions under the ambient O(3) regime, as prevailing at the forest site (control), or under an experimental twice-ambient O(3) regime (elevated O(3)), as released through a free-air canopy O(3) fumigation system. Gross carbon gain at the canopy-level declined by 1.7%, while respiratory carbon loss increased by 4.6% under elevated O(3). As this outcome only partly accounts for the decline in stem growth, O(3)-induced changes in allocation are referred to and discussed as crucial in quantitatively linking carbon gain with stem growth. PMID:22487316

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

2012-04-07

232

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)

233

Growth and foliar injury responses of maize, soybean and tomato seedlings exposed to mixtures of ozone and sulphur dioxide  

Energy Technology Data Exchange (ETDEWEB)

Experiments in controlled-environment chambers with three levels of ozone (O/sub 3/) (0, 0.08 and 0.15 microl l/sup -1/) and four levels of sulfur dioxide (SO/sub 2/) (0, 0.03, 0.12 and 0.30 microl l/sup -1/) for 6 h per day for 7 days) were used to obtain dose-response relationships for growth and foliar injury. Non-destructive covariate measurements were used to increase precision. All maize (Zea mays L., cv. Golden Jubilee) response variables had significant interactive effects between the pollutants. Soybean (Glycine max L., cv. Maple Arrow) leaf and stem dry weights had significant interactive effects between the pollutants. For tomato (Lycopersicon esculentum Mill., cv. New Yorker), leaf dry- and fresh-weights and visible injury had significant interactive effects between the pollutants. In all species, some growth variables were stimulated by the intermediate levels of single and/or combined pollutant treatments. In contrast, visible foliar injury increased with each concentration increment of single or mixed gases. A supplementary experiment involving two levels of O/sub 3/ and two levels of SO/sub 2/ indicated that dry matter allocation to roots and shoots varied with treatment and species. 3 figs., 6 tabs., 23 refs., 3 app.

Deveau, J.L.; Ormrod, D.P.; Allen, O.B.; Beckerson, D.W.

1987-07-01

234

Impact of cadmium and ozone on foliar symptom development, mineral composition, growth, yield and quality of woody and herbaceous plants  

Energy Technology Data Exchange (ETDEWEB)

Green mountain (GM), Norchip (NC) and Norland (NL) potato (Solanum tuberosum) cultivars were grown in the field under standard commercial practices to determine their relative susceptibility to oxidants and to evaluate the effectiveness of two antioxidants, EDU and benomyl, applied as soil drenches. The order of foliar susceptibility to oxidants was NL > NC > GM. Symptom severity directly correlated with cumulative oxidant dose, and the time of maximum plant sensitivity was cultivar-dependent. EDU significantly reduced foliar symptoms but benomyl did not. Untreated plants sustained up to a 31% reduction in tuber yield when compared to EDU treated plants. Reductions in specific gravity, tuber size and tuber number were year x cultivar dependent. The uptake and distribution of cadmium (Cd), another phytotoxic pollutant, in tobacco (Nicotiana tabacum L.) and tomato plants (Lycopersicon esculentum Mill.) grown in sand culture amended with 0 or 2.0 ..mu..g Cd/ml as CdCl/sub 2/ in a nutrient solution was compared. Tobacco accumulated twice as much Cd in the foliage as in the roots, whereas tomato plants contained only one-seventh as much Cd in the leaves. Although Cd-treated plants exhibited no visual toxicity symptoms, nor changes in percent dry weight, Mn and Fe concentrations were significantly reduced in the roots. Zinc concentrations of root and shoot tissue did not significantly change. When quaking aspen (Populus tremuloides) were grown in a sand substrate receiving nutrient solution amended with Cd (0-10 ..mu..g Cd/ml) and exposed to ozone (O/sub 3/) in a controlled and ambient environment, cadmium treated plants were more susceptible.

Clarke, B.B.

1982-01-01

235

Phenology and growth in four annual species grown in ambient and elevated CO2  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this study were to test the hypothesis that changes in phenology with CO{sub 2} are a function of the effect of CO{sub 2} upon growth and to determine if CO{sub 2}-induced changes in phenology can influence competitive outcome. The effect of 350, 525, and 700{mu}l/l CO{sub 2} on Guara brachycarpa, Gailardia pulchella, Oenothera laciniata, and Lupinus texenis was examined. Plants were grown as individuals in 150-, 500-, or 1000-ml pots and in competition in 1000-ml pots. Growth and development were monitored at twice-weekly intervals by recording the number of leaves and noting the presence or absence of stem elongation, branching, flower buds, and open flowers. Elevated CO{sub 2} affected both growth and phenology, but the direction and magnitude of effects varied with species and soil volume. Elevated CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} did not appear to affect development through its effect on growth. Those treatments in which there were significant effects of CO{sub 2} on growth were generally different from those treatments in which CO{sub 2} affected phenology. Rather than affecting phenology by changing plant size, CO{sub 2} appeared to affect phenology by modifying the size at which plants switched from one stage to the next. The level of CO{sub 2} changed competitive outcome; the importance of Lupinus increased whereas that of Oenothera decreased with increased CO{sub 2}. These changes were more closely related to the effect of CO{sub 2} on growth than its effect on phenology. 19 refs., 2 figs., 4 tabs.

Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada)); Bazzaz, F.A. (Harvard Univ., Cambridge, MA (USA))

1991-01-01

236

Changes in the levels of polyunsaturated fatty acids in the lung and lecithin cholesterol acyl transferase activity in plasma of monkeys exposed to ambient levels of ozone  

Energy Technology Data Exchange (ETDEWEB)

A group of 8 sub-adult bonnet monkeys (Macaca radiata) was exposed to 0.15 ppm ozone (O/sub 3/) and another group of 8 to 0.3 ppm O/sub 3/, 8 h/day, for 90 days. Four monkeys in the control group breathed filtered air during this period. Polyunsaturated fatty acids (PUFA) comprised about 22% of total fatty acids in the lungs of controls. The PUFA level decreased to about 90% and 6% in monkeys exposed to 0.15 ppm and 0.3 ppm O/sub 3/, respectively. Lecithin cholesterol acyl transferase (LCAT) activity in the plasma of monkeys exposed to 0.15 ppm O/sub 3/ was similar to that in the controls. However, the LCAT activity of plasma was significantly increased by the exposure of monkeys to 0.3 ppm O/sub 3/.

Rao, G.A.; Larkin, E.C.; Harkema, J.R.; Dungworth, D.L.

1985-02-01

237

Influence of phosphorus vapor ambient for InGaAsP growth on GaAs substrate  

Energy Technology Data Exchange (ETDEWEB)

For visible-light-emitting laser diodes, InGaAsP double heterostructures have been grown on GaAs substrates using liquid-phase epitaxy. As the growth temperature is as high as about 780 /sup 0/C, a large amount of phosphorus evaporates from the solutions for the cladding layers during the growth process. The phosphorus vapor disturbs the solution composition for the active layer, so that very thin and uniform active layers cannot be obtained. By using In-P-Sn solution and supplying the phosphorus partial pressure around the graphite boat, the influence of phosphorus vapor ambient for InGaAsP (lambda/sub P//sub L/ = 805 nm) growth is confirmed. When the phosphorus partial pressure increases, the surface of epitaxial layer becomes rough and the substrate is partly etched back. From x-ray diffraction and photoluminescence spectral measurements, the composition of the grown layer is also found to be changed. As a result of increasing the flow rate of H/sub 2/ gas in order to protect the solution for the active layer from phosphorus contamination, the double heterostructure wafers with the high-quality active layer can be obtained reproducibly. Thus, pulsed lasing operation at room temperature has been achieved. The lasing wavelength is 816 nm and the threshold current density is --4.6 kA/cm/sup 2/.

Ishikawa, J.; Ito, T.; Shin-ichi Takahashi, N.; Kurita, S.

1986-12-01

238

CCN estimates from bulk hygroscopic growth factors of ambient aerosols during the pre-monsoon season over Central Nepal  

Science.gov (United States)

Aerosol size distribution (ambient and dried) and chemical composition were measured simultaneously using two Scanning Mobility Particle Sizers (SMPSs) and filters during the pre-monsoon season (April-June 2009) at two locations in Central Nepal: Dhulikhel, an urban site in the Kathmandu valley, and Besisahar, a rural village in the Marsyangdi valley. Diameter growth factors (DGF) were estimated using the larger mode (around 100 nm) of the aerosol size distributions. The measured DGF suggest that the aerosols were in metastable state below 80% RH owing to the strong diurnal cycle of relative humidity (RH) at Dhulikhel, while no discernible growth was observed for Besisahar. Assuming ideal behavior of water-soluble organic compounds and using their fraction as determined by water extraction of filters produced the best agreement for a two-component hygroscopic growth model with the observed DGFs. This finding together with the DGF and chemical composition data were used to determine the aerosol bulk hygroscopicity parameter, ?. The ? parameter suggests that aerosols in this region are less hygroscopic than aerosols reported in previous studies from other regions. The estimated ? and the vertically scaled aerosol size distribution were then used to estimate the CCN spectra. These are the first estimates of CCN spectra from ground-based observations for the Central Himalaya region.

Shrestha, Prabhakar; Barros, Ana P.; Khlystov, Andrei

2013-03-01

239

Carbonic Anhydrase Is Essential for Growth of Ralstonia eutropha at Ambient CO2 Concentrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mutant strain 25-1 of the facultative chemoautotroph Ralstonia eutropha H16 had previously been shown to exhibit an obligately high-CO2-requiring (HCR) phenotype. Although the requirement varied with the carbon and energy sources utilized, none of these conditions allowed growth at the air concentra...

Kusian, Bernhard; Sültemeyer, Dieter; Bowien, Botho

240

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

 
 
 
 
241

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

242

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 induced stomatal closure. Combination between high O3 concentration and acid rain generally caused more closure of the stomata than other treatments. Water content and leaf area were significantly reduced in high O3 treatment. Furthermore, high O3 concentration increased the shoot/root ratio by reducing root growth more than shoot growth In contrast, low O3 concentration had no effect on these parameters. Acid rain, on the other hand, decreased root nodulation and N2-fixation, but it ameliorated O3 induced injury. The reduced O3 injury induced in the presence of acid rain treatment was probably achieved by decreasing O3 uptake through stomatal closure. Furthermore, leaves treated with acid rain became greener than those of control and other treatments due to the increase in chlorophyll concentration. Peroxidase (POD) activity showed a positive response to ozone and acid rain treatments either combined or separately.

Laila Ezzel-Arab Abdel Nasser

2002-01-01

243

Ozone, acidic precipitation, and soil Mg effects on growth and nutrition of loblolly pine seedlings after three growing seasons  

Energy Technology Data Exchange (ETDEWEB)

A study was initiated in 1987 to evaluate the impact of O{sub 3}, acidic precipitation, and soil Mg on the growth and nutrition of loblolly pine (Pinus taeda L.) seedlings. Thirty-six open top chambers equipped with a rainfall exclusion/addition system were utilized to administer three levels of O{sub 3} (subambient, ambient, and twice ambient) and two rainfall pH levels (3.8 and 5.2) to seedlings growing in 24-L plastic pots containing soil having either 35 or 15 mg kg{sup {minus}1} of exchangeable Mg. Each chamber contained 36 pots, and each treatment combination was replicated six times for a total of 1296 individual pots. After three seasons, biomass of all seedling components was progressively reduced with increasing O{sub 3} concentrations. Foliar nutrient leaching was not accelerated by increasing the acidity of precipitation from pH 5.2 to 3.8, and O{sub 3} did not act to exacerbate foliar leaching. Also, foliar nutrient concentrations were not significantly affected by precipitation pH or O{sub 3} treatments, and there was not accelerated soil leaching associated with chronic acidic precipitation. Differences in soil Mg treatments were reflected in soil solution and seedling Mg contents, but the 15 mg kg{sup {minus}1} soil Mg treatment was not sufficient to induce Mg deficiency in the seedlings. 24 refs., 6 figs., 2 tabs.

Edwards, G.S.; Kelly, J.M. (Tennessee Valley Authority, Norris, TN (USA)); Edwards, N.T. (Oak Ridge National Lab., TN (USA))

1991-01-01

244

Ozone Attack  

Science.gov (United States)

This activity has students observe how ozone can damage rubber bands and through a comparison, they will be able to determine the relative ozone levels for different locations. After completing this activity students will understand that tropospheric ozone is often called bad ozone because it breaks down certain materials, be able to explain that concentrations of ozone are not uniform, and demonstrate that the longer the exposure to ozone, the greater the effect. The page contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

245

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

UK PubMed Central (United Kingdom)

A field study was conducted to investigate the impact of ambient solar UV on the various growth, physiological and yield parameters of four sorghum (Sorghum bicolor L.) varieties-Indore-12, Indore-26, CSV-23 and Indore-27 by excluding either UV-B (<315 nm) or UV-A/B (<400 nm) components of solar spectrum. Exclusion of UV significantly enhanced plant height, area and specific leaf weight of flag leaf, biomass accumulation, yield parameters and harvest index in all the sorghum varieties. Chlorophyll b was significantly enhanced and chlorophyll a increased to a lesser extent, UV-B absorbing substances and chlorophyll a/b ratio were significantly decreased by the exclusion of solar UV. The enhancement in the vegetative growth and yield by UV exclusion might be linked to the remarkable increase in rate of photosynthesis in sorghum varieties. The magnitude of the response was high in I-26 and I-27 as compared to CSV-23 and I-12 after exclusion of solar UV. All the varieties of sorghum had a negative cumulative stress response index (CSRI), the sensitivity of the sorghum varieties was in the following sequence I-12>CSV-23>I-26>I-27. Thus I-27 was the most sensitive and I-12 the least sensitive variety to present level of solar UV radiation. The differences in UV sensitivity identified among sorghum varieties might be useful in breeding programs for increased tolerance to UV-B radiation.

Kataria S; Guruprasad KN

2012-11-01

246

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 is 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 CCF. 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 63 short period stations and 89 broadband stations in Taiwan. To remove the effects of temporal variations of the noises strength, the growing target CCFs are taken from a randomly daily CCF stack. 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 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. 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. For instance, we may evaluate how the CCF coda quality varies with trace length, and such measure allows us to make a meaningful choice for the window length of quality coda.

Chen, Ying-Nien; Gung, Yuancheng; Chiao, Ling-Yun

2013-04-01

247

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...

248

Local heating method for growth of aligned carbon nanotubes at low ambient temperature  

International Nuclear Information System (INIS)

[en] We use a highly localized resistive heating technique to grow vertically aligned multiwalled nanotube films and aligned single-walled nanotubes on substrates with an average temperature of less than 100 degree C. The temperature at the catalyst can easily be as high as 1000 degree C but an extremely high temperature gradient ensures that the surrounding chip is held at much lower temperatures, even as close as 1 ?m away from the local heater. We demonstrate the influence of temperature on the height of multiwalled nanotube films, illustrate the feasibility of sequential growth of single-walled nanotubes by switching between local heaters and also show that nanotubes can be grown over temperature-sensitive materials such as resist polymer

2008-01-01

249

Ozone disinfection machine  

UK PubMed Central (United Kingdom)

The utility model discloses an ozone disinfection machine comprising a framework used for supporting and locating, an ozone liquid supplying pipe arranged on the framework, an ozone waste liquid discharging pipe, a cleaning disinfection pool used for cleaning and pre-disinfecting, a two-stage ozone disinfecting groove used for the secondary disinfection, a transmitting mechanism which comprises a conveyer belt traversed through the two-stage ozone disinfecting groove, a cleaning device which comprises an electric cleaning hair brush used for brushing the conveyer belt, and a ventilating system. The ozone disinfection machine can continuously process and disinfect fresh fillets after coloring processing treatment, after the secondary disinfection, can realize the aims of removing peculiar smell, and restraining the growth of germ and improving the abilities of corrosion-resisting and fresh-keeping, and can guarantee the stable quality of products, thereby greatly improving the manufacturing efficiency. Since the disinfecting medium is ozone liquid, and any noxious chemical materials can not added on the products, the machine is safe and reliable.

XIAOCHUN YIN

250

Ozone Pollution  

Medline Plus

Full Text Available ... the stratosphere) shields us from much of the sun’s ultraviolet radiation. However, ozone air pollution at ground ... VOCs come in contact with both heat and sunlight, they combine and form ozone smog. NOx is ...

251

Ozone Pollution  

Medline Plus

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

252

Ozone Pollution  

Medline Plus

Full Text Available ... receive medical treatment and to go to the hospital. 29 Breathing ozone for longer periods can alter ... in ozone. 33 New York researchers looking at hospital records for children’s asthma found that the risk ...

253

Ozone Pollution  

Medline Plus

Full Text Available ... of the most dangerous. Scientists have studied the effects of ozone on health for decades. Hundreds of ... groups of people are especially vulnerable to the effects of breathing ozone: children and teens; anyone 65 ...

254

Ozone Pollution  

Medline Plus

Full Text Available ... as mowing your lawn or refilling your gas tank during daylight hours. Lawn mower exhaust and gasoline ... ozone doesn’t form, so refilling your gas tank after dark is better on high ozone days. ...

255

Ozone Pollution  

Medline Plus

Full Text Available ... 2012 > Health Risks Health Risks Ozone Particle Pollution Children's Health Disparities Near Highways Protect Yourself Take Action ... especially vulnerable to the effects of breathing ozone: children and teens; anyone 65 and older; people who ...

256

Ozone Pollution  

Medline Plus

Full Text Available ... VOCs come in contact with both heat and sunlight, they combine and form ozone smog. NOx is ... in the heat and sun. Take away the sunlight and ozone doesn’t form, so refilling your ...

257

Ozone Pollution  

Medline Plus

Full Text Available ... of the most dangerous. Scientists have studied the effects of ozone on health for decades. Hundreds of research ... groups of people are especially vulnerable to the effects of breathing ozone: children and teens; anyone 65 and ...

258

Ozone Pollution  

Medline Plus

Full Text Available ... occur: “ Ozone is capable of causing inflammation in the lung at lower concentrations than any other gas. Such ... 29 Breathing ozone for longer periods can alter the lungs’ ability to function. Two studies published in 2005 ...

259

Ozone Pollution  

Medline Plus

Full Text Available ... Ozone? Ozone (O 3 ) is an extremely reactive gas molecule composed of three oxygen atoms. It is ... emitted from motor vehicles, chemical plants, refineries, factories, gas stations, paint and other sources. The formula for ...

260

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

International Nuclear Information System (INIS)

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

2003-02-03

 
 
 
 
261

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

Directory of Open Access Journals (Sweden)

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

André Trevisan; Sandro Santos

2011-01-01

262

Determinants of ozone fluxes and metrics for ozone risk assessment in plants.  

UK PubMed Central (United Kingdom)

Tropospheric ozone concentration is increasing and represents a threat to single plants and whole ecosystems. The deleterious ozone effects mainly occur when (i) ozone concentration in the air builds up; (ii) the pollutant enters the leaf through stomatal uptake, and (iii) ozone-produced reactive oxygen species are not efficiently scavenged by leaf antioxidants and then oxidize leaf tissues. The sensitivity of plants to ozone is species-specific, and a correct risk assessment should be based on a metric that correctly takes into account the ambient concentration of ozone, the physiological control on stomatal apertures, and the efficiency of leaf antioxidant system. Current methodologies have been analysed to evaluate ozone risk assessment, and, by phasing-in and phasing out sources and sinks of ozone, elements of improvements for the current metrics have been suggested.

Fares S; Goldstein A; Loreto F

2010-03-01

263

Ozone effects on growth and assimilate partitioning in alfalfa, Medicago sativa L.  

UK PubMed Central (United Kingdom)

Alfalfa (Medicago sativa L.) were exposed to O(3) concentrations varying between 118 x 10(-6) microg cm(-3) (0.06 ppm) and 157 x 10(-6) microg cm(-3) (0.08 ppm) for 6 h per day 5 days per week for several weeks. Typical plants were sacrificed weekly, and growth parameters were measured. O(3) reduced overall growth, relative growth rates and unit leaf rates in alfalfa before it was cut, indicating that O(3) had reduced photosynthesis. However, after the alfalfa was cut, these same parameters indicated that in some cases, O(3)-stressed plants had greater photosynthetic rates than controls during regrowth. O(3) also altered dry matter partitioning. Roots were most affected, followed by leaves and stems, respectively. In general, O(3) reduced photosynthate production and reduced the proportion of photosynthate partitioned to roots relative to leaves and stems. This could reduce starch reserves in alfalfa, and be detrimental to stand longevity. However, the post-cutting study indicated that at least some alfalfa cultivars may be able to acclimate to O(3)-stress, though plants did not fully recover from pre-cutting differences.

Cooley DR; Manning WJ

1988-01-01

264

Growth and yield effects of ambient air pollution on Valencia orange trees. Final report, 21 December 1987-30 September 1989  

Energy Technology Data Exchange (ETDEWEB)

The study was conducted at the University of California, Riverside to determine the effects of photochemical oxidants or sulfur dioxide on orange tree growth and productivity. Researchers exposed Valencia orange trees in open-top field chambers to ambient air, carbon filtered air, a mixture of half ambient and half filtered air, or sulfur dioxide continuously at 0.09 ppm. The ambient air treatment reduced yield an average of 30%, compared to filtered air, but had little effect on fruit quality, and no observable effect on vegetative growth. Ambient oxidant exposure decreased stomatal conductance and leaf water potential, but did not reduce photosynthetic rates. Exposure to ambient oxidants resulted in higher levels of starch in leaves prior to flowering compared with exposure to filtered air but did not affect other biochemical variables. The sulfur dioxide treatment reduced fruit yield an average of 31% compared with filtered air. The sulfur dioxide treatment resulted in higher rates of transpiration during the summer months, but the investigators deemed the increase too small to be of biological importance.

Olszyk, D.M.

1989-08-01

265

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 forty Ross 708 chicks were randomly distributed into 9 environmentally controlled chambers (30 males and 30 females chicks/chamber) at 1 d of age. Feed and water were provided ad libitum. Birds were provided a four phase-feeding program (starter: 1 to 14 d, grower: 15-28 d, finisher: 29-42 d and withdrawal: 43-56 d). At 56 d of age, both feed intake and birds’ weight were recorded for the growth performance. Also, 20 (10 males and 10 females) birds from each chamber were processed to determine weights and yields. Broilers subjected to high ambient temperature of 26.7oC had significantly (P0.05) lower BW, BWG, FI, carcass weight and pectoralis major and minor weights along with a significant (P0.05) increased in FCR when compared with low and moderate ambient temperatures broilers. Plasma corticosterone concentrations were not statistically affected by temperature, light intensity or their interaction, suggesting an absence of stress. These results indicate that exposure of modern heavy weight broilers to high ambient temperature of 26.7oC in comparison with low and moderate ambient temperatures has a negative effect on growth performance and carcass characteristics, suggesting that they need to be grown under lower ambient temperature than previously reported.

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

2010-01-01

266

Effects of photochemical oxidant on the growth of poplar cuttings. III. Effects of ozone on photosynthesis, photorespiration and dark respiration  

Energy Technology Data Exchange (ETDEWEB)

The effects of ozone on apparent photosynthesis, photorespiration and dark respiration were determined in poplar (Populus x euramericana cv. I 45/51) leaves. These results were as follows: the lower order leaves (at the 35th day after unfolding) fumigated with ozone at 0.10, 0.15, 0.20, or 0.25 ppm had apparent photosynthetic rates reduced by 3, 7, 28 and 34%, respectively, after 5 hours exposure. On the other hand, photosynthesis of the upper order leaves (at the 20th day after unfolding) were not affected with 0.10 or 0.20 ppm ozone for 5 hours exposure. After fumigating to poplar cuttings with 0.10 ppm ozone for 5 hours a day, 5 days a week, during the 1- and 2-week treatment period, apparent photosynthetic rates of the lower order leaves were reduced by 33% and 59% respectively, and photorespiratory rates were reduced by 19% and 40% respectively. But, dark respiratory rates were stimulated by 15% during the 1-week treatment. On the other hand, those of the upper order leaves were not affected by ozone fumigation. Apparent photosynthetic rates of injured leaves shown as damage degree 3 or 5 by fumigations with 0.10 ppm ozone, 5 hours a day for 5 days, were depressed 10% and 22%, respectively, by fumigating again to 0.10 ppm ozone for 3 hours. When poplar cuttings grown in non-filtered air greenhouse and filtered air greenhouse were fumigated with 0.15 ppm ozone for 3 hours, apparent photosynthetic rates of the lower leaves in non-filtered air greenhouse were reduced by 11%, but those in filtered air greenhouse were not affected. At one day after fumigation, the rates in non-filtered air greenhouse were reduced by 28%.

Kuno, H.

1980-01-01

267

Ozone disinfector  

UK PubMed Central (United Kingdom)

The utility model discloses an ozone disinfector which comprises an air pump and an ozone generator that is connected by pipeline. An air moisture absorption and purifying device that is made of dry filter is installed between the air pump and the ozone generator. The utility model is with simple structure and can absorb moisture and dry the air supplied by the air pump while exercise filtering and dedusting so as to fully discharge the ozone generate to produce high density ozone and to improve disinfection effect.

ZHANG JIAYUN

268

Alterações bioquímicas associadas a injúrias foliares visíveis em plantas jovens de Psidium guajava 'Paluma' mantidas em ambiente contaminado por ozônio/ Biochemical alterations associate with visible foliar injury in saplings of Psidium guajava 'Paluma' maintained in an environment polluted by ozone  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Psidium guajava 'Paluma' é sensível ao ozônio, ao qual responde com características injúrias foliares visíveis. Foram avaliadas a concentração de ácido ascórbico (AA) e a atividade das enzimas superóxido dismutase (SOD) e peroxidases (POD) em folhas novas e velhas de plantas expostas (n = 13) em região contaminada por ozônio (Ibirapuera, São Paulo, SP) e em um ambiente controlado (casa de vegetação com ar filtrado), com o objetivo de avaliar a ocorrência (more) de injúrias latentes (alteração em AA, SOD e/ou POD) e se a ocorrência destas diferia entre folhas com ou sem injúrias visíveis. A concentração de AA foi maior nas plantas do Ibirapuera, sem diferença entre novas ou velhas e com ou sem injúrias. A atividade de SOD e POD diferiu entre folhas novas e velhas, mas não com relação ao local de exposição e a presença ou ausência de injúrias foliares. Não houve decréscimo na biomassa das plantas expostas no Ibirapuera. Conclui-se que em P guajava 'Paluma' SOD e POD não estão relacionadas à proteção contra injúrias foliares visíveis nessa espécie e que o AA é um indicador de injúria latente. Abstract in english Psidium guajava 'Paluma' is sensitive to ozone, to which reacts with characteristic visible foliar injuries. The concentration of ascorbic acid (AA) and the activity of enzymes superoxide dismutase (SOD) and peroxidase (POD) had been evaluated in new and old leaves of plants exposed (n = 13) to ozone in a contaminated area (Ibirapuera, São Paulo, SP) and in a controlled environment (glasshouse with filtered air) to assess the occurrence of latent injuries (alteration in (more) AA, SOD and/or POD) and if the occurrence of these differed between leaves with or without visible injuries. The AA concentration was higher in plants of Ibirapuera, without difference between new or old and with or without visible injuries. The activity of SOD and POD differed between new and old leaves, but not with relation to the site of exposition and the presence or absence of foliar injuries. There was no significant decrease in biomass in plants exposed in Ibirapuera. We conclude that in P. guajava 'Paluma' SOD and POD are not related to the protection against visible foliar injuries and that the AA is a indicator of latent injury.

Dias, Ana Paula de Souza; Rinaldi, Mirian Cilene Spasiani; Moraes, Regina Maria de

2007-01-01

269

Effects of simulated acidic rain applied alone and in combination with ambient rain on growth and yield of field-grown snap bean  

Energy Technology Data Exchange (ETDEWEB)

Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four levels of acidity at pH values of 5.0, 4.2, 3.4 and 2.6 were applied in four replicate treatments and the experiment was conducted in two successive years (1981 and 1982). In plots that received only simulated rain, yield was not adversely affected by acidic rain; in 1981, a positive linear relationship was present between acidity of simulated rain and yield, but in 1981, no effect was found. In contrast, in plots that received both simulated and ambient rain, a negative linear relationship between acidity in simulated rain and yield was observed in both years.

Troiano, J.; Jacobson, J.S.; Heller, L.

1984-01-01

270

78 FR 44439 - Approval and Promulgation of Implementation Plans: Atlanta, Georgia 1997 8-Hour Ozone...  

Science.gov (United States)

...Promulgation of Implementation Plans: Atlanta, Georgia 1997 8-Hour Ozone Nonattainment Area...2013, direct final rule to approve Georgia's October 21, 2009, state implementation...plan requirements for the Atlanta, Georgia 1997 8-hour ozone national ambient...

2013-07-24

271

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

Energy Technology Data Exchange (ETDEWEB)

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

Dawnay, Louise [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW (United Kingdom); School of Biological Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW (United Kingdom); Mills, Gina [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW (United Kingdom)], E-mail: gmi@ceh.ac.uk

2009-02-15

272

Slow fatigue crack growth in aluminium and magnesium cast alloys in ambient air and in a vacuum; Langsames Ermuedungsrisswachstum in Aluminium- und Magnesiumgusslegierungen in Raumluft und in Vakuum  

Energy Technology Data Exchange (ETDEWEB)

The influence of ambient air on near threshold fatigue crack growth in the magnesium cast alloys AZ91 hp, AM60 hp and AS21 hp and in the aluminium cast alloy AlSi9Cu3 has been investigated. Fatigue crack growth properties at a cycling frequency of 20 kHz in ambient air and in a vacuum are significantly different. In a vacuum, the threshold stress intensity amplitude of the aluminium alloy is 30% higher than in ambient air, and the threshold values of the magnesium alloys in a vacuum are up to 85% higher than in ambient air. Moisture of ambient air is responsible for accelerated crack growth at growth rates below 1 - 3 x 10{sup -9} m/cycle (AlSi9Cu3) and 2 - 5 x 10{sup -8} m/cycle (magnesium alloys), respectively. In ambient air a minimum crack growth rate of 5 x 10{sup -11} - 2 x 10{sup -10} m/cycle was observed, whereas far lower minimum growth rates were found in a vacuum. (orig.) [German] Die Arbeit beschaeftigt sich mit dem Einfluss des Umgebungsmediums Raumluft auf das sehr langsame Ermuedungsrisswachstum in den druckgegossenen Magnesiumlegierungen AZ91 hp, AM60 hp und AS21 hp und in der druckgegossenen Aluminiumlegierung AlSi9Cu3. Die bei einer Beanspruchungsfrequenz von 20 kHz gemessenen Rissausbreitungskurven in Raumluft und Vakuum unterscheiden sich im Schwellwertbereich deutlich. Der Schwellwert der Aluminiumlegierung liegt in Vakuum 30% hoeher als in Raumluft, und die Schwellwerte der Magnesiumlegierungen liegen bis zu 85% hoeher. Die in der Raumluft enthaltene Luftfeuchtigkeit ist massgeblich fuer die Beschleunigung des Risswachstums, wobei ein Einfluss bei AlSi9Cu3 bis zu Risswachstumsgeschwindigkeiten von 1 - 3 x 10{sup -9} m/Lastspiel und bei den Magnesiumlegierungen bis zu 2 - 5 x 10{sup -8} m/Lastspiel gefunden wird. In Raumluft wachsen Ermuedungsrisse mit einer Wachstumsgeschwindigkeit von mindestens 5 x 10{sup -11} - 2 x 10{sup -10} m/Lastspiel, waehrend in Vakuum auch wesentlich niedrigere Wachstumsraten gefunden wurden. (orig.)

Fuchs, U.; Mayer, H.; Tschegg, S.; Zettl, B. [Vienna Univ. (Austria). Inst. fuer Meteorologie und Geophysik; Lipowsky, Hj.; Stich, A. [Audi AG, Ingolstadt (Germany); Papakyriacou, M. [ARC Leichtmetallkompetenzzentrum Ranshofen GmbH, Ranshofen (Austria)

2002-01-01

273

Ozone, antioxidant spray and Meloidogyne hapla effects on tobacco  

Energy Technology Data Exchange (ETDEWEB)

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/sup -1/ to protect against oxidant injury. O/sub 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/sub 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.

1984-01-01

274

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.

275

Ozone Depletion  

Science.gov (United States)

The ozone layer forms a thin shield in the upper atmosphere, protecting life onEarth from the suns ultraviolet (UV) rays. In the 1980s, scientists began accumulating evidence that the ozone layer was being depleted. Depletion of the ozone layer results in increased UV radiation reaching the Earths surface, which in turn can lead to a greater chance of overexposure to UV radiation and the related health effects of skin cancer, cataracts, and immune suppression.

U.S. Environmental Protection Agency (EPA;Office of Air and Radiation)

2008-04-25

276

Tropospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

This book provides scientists, regulators, industry and public interest groups, students, and the general public with an overview of effects, control, enforcement and public policy related to tropospheric ozone. The two major sections are (1) ozone effects, exposure, risk, and regulation (including supporting information for human health and vegetation effects) and (2) perspectives on tropospheric ozone pollution (including Clean Air Amendments, local program initiative, costs of attaining ozone air quality standards, the Federal enforcement role, American Lung Association perspective, and the petroleum industry prospective).

McKee, D.J.

1994-12-31

277

Ozone threat  

International Nuclear Information System (INIS)

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

1995-01-01

278

Ozone sterilizer  

UK PubMed Central (United Kingdom)

The utility model, conducting the research for developing an ozonic-sterilization device with a mechanism for easily eliminating the discharging obstruct, whose ozonic-sterilization device (1)'s box (11) is provided with an ozonic generating module (12) with free assembly and disassembly. A discharge electrode of the ozonic generating module's ozonic generator (121) is embedded inside an air stream cylinder (125) whose intake port (125a) is communicated with an intake part and an exhaust port (125b) is opened outward the box a high voltage applied section (124) of the ozonic generating module is connected with a power source through a connector linked with the ozonic generating module in mounting direction or disassembled freely the ozonic generating module, by being pulled out along mounting direction, disassembled the connector between the high voltage applied section (124) and the power source, thus to be released from the box in addition, the device, cleaning the discharge electrode by the water flows into the air stream cylinder of the ozonic generator, to eliminate the discharging obstruct cumulated on the discharge electrode.

MASASHIRO NIETA

279

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

UK PubMed Central (United Kingdom)

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 temperature, the convective heat transfer coefficient and the growth parameters of the micro organism of concern. For the validation of the overall model, five different combinations of ambient air temperature (ranging from 8 degrees C to 12 degrees C), product thickness (ranging from 1 cm to 6 cm) and convective heat transfer coefficient (ranging from 8 W/(m(2) K) to 60 W/(m(2) K)) were tested during a cooling procedure. Moreover, three different ambient air temperature scenarios assuming alternated cooling and heating stages, drawn from real refrigerated food processes, were tested. General agreement between predicted and observed bacterial growth was obtained and less than 5% of the experimental data fell outside the 95% confidence bands estimated by the bootstrap percentile method, at all the tested conditions. Accordingly, the overall model was successfully validated for isothermal and dynamic refrigeration cycles allowing for temperature dynamic changes at the centre and at the surface of the product. The major impact of the convective heat transfer coefficient and the product thickness on bacterial growth during the product cooling was demonstrated. For instance, the time needed for the same level of bacterial growth to be reached at the product's half thickness was estimated to be 5 and 16.5 h at low and high convection level, respectively. Moreover, simulation results demonstrated that the predicted bacterial growth at the air ambient temperature cannot be assumed to be equivalent to the bacterial growth occurring at the product's surface or centre when convection heat transfer is taken into account. Our results indicate that combining food engineering and predictive microbiology models is an interesting approach providing very useful tools for food safety and process optimisation.

Ben Yaghlene H; Leguerinel I; Hamdi M; Mafart P

2009-07-01

280

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

Science.gov (United States)

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 temperature, the convective heat transfer coefficient and the growth parameters of the micro organism of concern. For the validation of the overall model, five different combinations of ambient air temperature (ranging from 8 degrees C to 12 degrees C), product thickness (ranging from 1 cm to 6 cm) and convective heat transfer coefficient (ranging from 8 W/(m(2) K) to 60 W/(m(2) K)) were tested during a cooling procedure. Moreover, three different ambient air temperature scenarios assuming alternated cooling and heating stages, drawn from real refrigerated food processes, were tested. General agreement between predicted and observed bacterial growth was obtained and less than 5% of the experimental data fell outside the 95% confidence bands estimated by the bootstrap percentile method, at all the tested conditions. Accordingly, the overall model was successfully validated for isothermal and dynamic refrigeration cycles allowing for temperature dynamic changes at the centre and at the surface of the product. The major impact of the convective heat transfer coefficient and the product thickness on bacterial growth during the product cooling was demonstrated. For instance, the time needed for the same level of bacterial growth to be reached at the product's half thickness was estimated to be 5 and 16.5 h at low and high convection level, respectively. Moreover, simulation results demonstrated that the predicted bacterial growth at the air ambient temperature cannot be assumed to be equivalent to the bacterial growth occurring at the product's surface or centre when convection heat transfer is taken into account. Our results indicate that combining food engineering and predictive microbiology models is an interesting approach providing very useful tools for food safety and process optimisation. PMID:19447512

Ben Yaghlene, H; Leguerinel, I; Hamdi, M; Mafart, P

2009-04-24

 
 
 
 
281

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

International Nuclear Information System (INIS)

Treatments with ethylenediurea (EDU) protect plants from ozone foliar injury, but the processes underlying this protection are poorly understood. Adult ash trees (Fraxinus excelsior), with or without foliar ozone symptoms in previous years, were treated with EDU at 450 ppm by gravitational trunk infusion in May-September 2005 (32.5 ppm h AOT40). At 30-day intervals, shoot growth, gas exchange, chlorophyll a fluorescence, and water potential were determined. In September, several biochemical parameters were measured. The protective influence of EDU was supported by enhancement in the number of leaflets. EDU did not contribute its nitrogen to leaf tissue as a fertiliser, as determined from lack of difference in foliar N between treatments. Both biochemical (increase in ascorbate-peroxidase and ascorbic acid, and decrease in apoplastic hydrogen peroxide) and biophysical (decrease in stomatal conductance) processes regulated EDU action. As total ascorbic acid increased only in the asymptomatic trees, its role in alleviating O3 effects on leaf growth and visible injury is controversial. - Both biochemical and biophysical processes may regulate EDU action.

2008-01-01

282

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

Energy Technology Data Exchange (ETDEWEB)

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

Paoletti, Elena [IPP-CNR, Via Madonna del Piano 10, Sesto Fiorentino, I-50019 Florence (Italy)], E-mail: e.paoletti@ipp.cnr.it; Contran, Nicla [Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, Milan (Italy); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States); Castagna, Antonella; Ranieri, Annamaria [Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, Pisa (Italy); Tagliaferro, Francesco [IPLA, Corso Casale 476, I-10128 Turin (Italy)

2008-10-15

283

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

Science.gov (United States)

Treatments with ethylenediurea (EDU) protect plants from ozone foliar injury, but the processes underlying this protection are poorly understood. Adult ash trees (Fraxinus excelsior), with or without foliar ozone symptoms in previous years, were treated with EDU at 450 ppm by gravitational trunk infusion in May-September 2005 (32.5 ppm h AOT40). At 30-day intervals, shoot growth, gas exchange, chlorophyll a fluorescence, and water potential were determined. In September, several biochemical parameters were measured. The protective influence of EDU was supported by enhancement in the number of leaflets. EDU did not contribute its nitrogen to leaf tissue as a fertiliser, as determined from lack of difference in foliar N between treatments. Both biochemical (increase in ascorbate-peroxidase and ascorbic acid, and decrease in apoplastic hydrogen peroxide) and biophysical (decrease in stomatal conductance) processes regulated EDU action. As total ascorbic acid increased only in the asymptomatic trees, its role in alleviating O(3) effects on leaf growth and visible injury is controversial. PMID:18331769

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

2008-03-10

284

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.

Srebot Vera; Gianicolo Emilio AL; Rainaldi Giuseppe; Trivella Maria; Sicari Rosa

2009-01-01

285

Ozone Pollution  

Medline Plus

Full Text Available ... exposures to ozone. The three teams—at Harvard, Johns Hopkins and New York University—used different approaches but all came to similar conclusions. All three studies reported a small but robust association between daily ozone levels ...

286

Ozone Pollution  

Medline Plus

Full Text Available ... atoms. It is the primary ingredient of smog air pollution and is very harmful to breathe. Ozone attacks ... much of the sun’s ultraviolet radiation. However, ozone air pollution at ground level where we can breathe it ( ...

287

A meta-analysis of the effects of high ambient temperature on growth performance of growing-finishing pigs.  

UK PubMed Central (United Kingdom)

High ambient temperature (T) is one of the most important climatic factors influencing pig performance. Increased T occurs sporadically during summer heat waves in temperate climates and year round in tropical climates. Results of published experiments assessing the effects of high T on pig performance are surprisingly variable. Thus, a meta-analysis was performed to aggregate our knowledge and attempt to explain differences in the results across studies on the effect of increased T on ADFI and ADG in growing-finishing pigs. Data for ADFI and ADG were extracted from 86 and 80 trials, respectively, from articles published in scientific journals indexed in PubMed, Science Direct, and from proceedings of scientific meetings through November 2009. Data on ADFI and ADG were analyzed using a linear mixed model that included the linear and the quadratic effects of T and BW, and their interactions as continuous, fixed effects variables, and the trial as a random effect factor (i.e., block). In addition, the effects of housing type (2 levels: individual and group housing) and the year of publication (3 levels: 1970 to 1989, 1990 to 1999, and 2000 to 2009) on the intercept and the linear regression term for T (i.e., the slope) were also tested. Results showed that high T had a curvilinear effect on ADFI and ADG and that this effect was more pronounced in heavier pigs. Across T, ADFI was less when pigs were group-housed. The intercept and the regression coefficient (slope) for T were significantly affected by the year of publication. The effect of increased T was greater in more contemporary works, suggesting that modern genotypes could be more sensitive to heat stress than older genotypes of lesser growth potential. In conclusion, pig performance decreases at an accelerating rate as T is increased. The large between-study variability on the effects of high T on pig performance is partially explained by differences in pig BW and to a lesser extent by the year the study was published.

Renaudeau D; Gourdine JL; St-Pierre NR

2011-07-01

288

A meta-analysis of the effects of high ambient temperature on growth performance of growing-finishing pigs.  

Science.gov (United States)

High ambient temperature (T) is one of the most important climatic factors influencing pig performance. Increased T occurs sporadically during summer heat waves in temperate climates and year round in tropical climates. Results of published experiments assessing the effects of high T on pig performance are surprisingly variable. Thus, a meta-analysis was performed to aggregate our knowledge and attempt to explain differences in the results across studies on the effect of increased T on ADFI and ADG in growing-finishing pigs. Data for ADFI and ADG were extracted from 86 and 80 trials, respectively, from articles published in scientific journals indexed in PubMed, Science Direct, and from proceedings of scientific meetings through November 2009. Data on ADFI and ADG were analyzed using a linear mixed model that included the linear and the quadratic effects of T and BW, and their interactions as continuous, fixed effects variables, and the trial as a random effect factor (i.e., block). In addition, the effects of housing type (2 levels: individual and group housing) and the year of publication (3 levels: 1970 to 1989, 1990 to 1999, and 2000 to 2009) on the intercept and the linear regression term for T (i.e., the slope) were also tested. Results showed that high T had a curvilinear effect on ADFI and ADG and that this effect was more pronounced in heavier pigs. Across T, ADFI was less when pigs were group-housed. The intercept and the regression coefficient (slope) for T were significantly affected by the year of publication. The effect of increased T was greater in more contemporary works, suggesting that modern genotypes could be more sensitive to heat stress than older genotypes of lesser growth potential. In conclusion, pig performance decreases at an accelerating rate as T is increased. The large between-study variability on the effects of high T on pig performance is partially explained by differences in pig BW and to a lesser extent by the year the study was published. PMID:21297065

Renaudeau, D; Gourdine, J L; St-Pierre, N R

2011-02-04

289

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

DEFF Research Database (Denmark)

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 268C), one (HC; 168C to 268C) or no (CC; 168C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Nielsen, Birte LindstrØm

2012-01-01

290

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

Directory of Open Access Journals (Sweden)

Full Text Available 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

2011-01-01

291

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 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 resul (more) ts showed a significant inverse association between the enhancement in vegetative growth and number of pods among the cultivars tested, indicating differences in the carbon partitioning amongst the cultivars by the way of exclusion of solar UV-B. NRC-7, Pusa-24 and JS-335 showed maximum promotion in vegetative growth and less enhancement in crop yield after solar UV-B exclusion. Kalitur, JS71-05, Hardee, PK-472 and PK-1029 showed improved performance both in terms of number of pods/plant and seed weight after solar UV-B exclusion. An enhancement in the crop yield by exclusion of solar UV-B indicated poor response of the cultivar to the ambient solar UV-B; these cultivars would be more suitable at latitudes, which received less UV-B. According to UV-SI, sensitivity of eight Indian soybean cultivars to ambient level of UV-B (280-320 nm) radiation had the following descending order; PK-472 > JS-335 > Hardee > Kalitur > JS71-05 > Pusa-24 > NRC-7 > PK-1029. These findings suggest the way to select the best-suited cultivar for particular latitude.

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

2011-01-01

292

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

293

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 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)

294

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-05-01

295

Ozone Depletion  

Science.gov (United States)

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

Pratte, John

296

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

Science.gov (United States)

Four populations of Anthoxanthum odoratum from North Wales, UK, were exposed to the following combinations of mean background and peak concentrations of ozone for 12 weeks in solardomes: LL (14.3 ppb, 18.9 ppb, respectively), LH (14.8 ppb, 52.3 ppb), HL (28.9 ppb, 35.7 ppb) and HH (30.5 ppb, 72.1 ppb). Elevated ozone rapidly induced premature senescence, with effect increasing in the order: LLgrowth and tillering were less pronounced than effects on senescence. PMID:18980787

Dawnay, Louise; Mills, Gina

2008-11-05

297

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-07-15

298

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

International Nuclear Information System (INIS)

The effect of free-air ozone fumigation and crown position on antioxidants were determined in old-growth spruce (Picea abies) trees in the seasonal course of two consecutive years (2003 and 2004). Levels of total ascorbate and its redox state in the apoplastic washing fluid (AWF) were increased under double ambient ozone concentrations (2 x O3), whilst ascorbate concentrations in needle extracts were unchanged. Concentrations of apoplastic and symplastic ascorbate were significantly higher in 2003 compared to 2004 indicating a combined effect of the drought conditions in 2003 with enhanced ozone exposure. Elevated ozone had only weak effects on total glutathione levels in needle extracts, phloem exudates and xylem saps. Total and oxidised glutathione concentrations were higher in 2004 compared to 2003 and seemed to be more affected by enhanced ozone influx in the more humid year 2004 compared to the combined effect of elevated ozone and drought in 2003 as observed for ascorbate. - Antioxidant defence in sun and shade needles of Picea abies under free-air ozone fumigation in the seasonal course of two consecutive years.

2008-01-01

299

Ozone Pollution  

Medline Plus

Full Text Available ... oxygen atoms. It is the primary ingredient of smog air pollution and is very harmful to breathe. ... heat and sunlight, they combine and form ozone smog. NOx is emitted from power plants, motor vehicles ...

300

Ozone Pollution  

Medline Plus

Full Text Available ... after dark is better on high ozone days. Since we can’t control sunlight and heat, we ... public health in the US, despite real progress since 1970. Help us Fight For Air! | See more ...

 
 
 
 
301

Ozone Pollution  

Medline Plus

Full Text Available ... form ozone smog. NOx is emitted from power plants, motor vehicles and other sources of high-heat combustion. VOCs are emitted from motor vehicles, chemical plants, refineries, factories, gas stations, paint and other sources. ...

302

Ozone Pollution  

Medline Plus

Full Text Available ... effect would be a hazard to anyone with heart failure and pulmonary congestion, and would worsen the ... lung function. 30 Inhaling ozone may affect the heart as well as the lungs. A 2006 study ...

303

Ozone Pollution  

Medline Plus

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

304

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.

305

Ozone Pollution  

Medline Plus

Full Text Available ... from ozone. A study published in 2010 examined records from ten cities in Italy and found women, ... increase the risk of early death. Examining the records from a long-term national database, researchers found ...

306

Ozone Pollution  

Medline Plus

Full Text Available ... come out of tailpipes, smokestacks and many other sources. These essential raw ingredients for ozone are nitrogen ... emitted from power plants, motor vehicles and other sources of high-heat combustion. VOCs are emitted from ...

307

Analysis and monitoring of ozone in cooling water systems: A state of the art paper  

Energy Technology Data Exchange (ETDEWEB)

This is a State of the Art paper. This paper includes an overview of the current techniques for liquid and gas phase ozone monitoring. The paper also includes specific techniques for Ozone monitoring, a list of ozone monitor manufacturers, and a bibliography. This paper presents and overview of the current techniques for liquid and gas phase ozone monitoring. If the ozone concentration in cooling water is too high, ozone induced corrosion or off-gassing of ozone can occur. If the dissolved ozone concentration is too low, biological growth can develop. The paper includes an appendix which contains the following summaries: Calibration method for residual ozone by the oxidation of nitrite; Colorimetric method for the determination of residual ozone in water (Indigo-trisulfonate method and ACVK method); Colorimetric method for the determination of traces of ozone in water; Electrochemical method for continuous measurement of residual ozone in water; and Photometric measurement of low ozone concentration in the gas phase.

McGrane, W.K. [TriOx, Dublin, CA (United States)

1994-12-31

308

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; Slesak, Ireneusz; Cebula, Stanis?aw; Waligórski, Piotr; Dziurka, Micha?; Skoczowski, Andrzej; Miszalski, Zbigniew

2013-06-14

309

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

UK PubMed Central (United Kingdom)

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.

Rozp?dek P; Slesak I; Cebula S; Waligórski P; Dziurka M; Skoczowski A; Miszalski Z

2013-09-01

310

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-10-15

311

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

International Nuclear Information System (INIS)

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

312

Ozone fact sheet: the ozone layer  

Energy Technology Data Exchange (ETDEWEB)

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

NONE

1999-07-01

313

Influence of ozone on induced resistance in soybean to the Mexican bean beetle (Coleoptera: Coccinellidae)  

Energy Technology Data Exchange (ETDEWEB)

The influence of ozone (O{sub 3}) on induced resistance in soybean, Glycine max (L.) Merr., cv. Williams 82, was investigated. Feeding by larval soybean looper, Pseudoplusia includens (Walker), was used to induce resistance, and the feeding preference of the Mexican bean beetle, Epilachna varivetis Mulsant, was used to indicate induced resistance. Greenhouse grown soybean plants at the V9 growth stage (eight open trifoliolates) were used in all experiments. One day following feeding injury by the soybean looper, the injured plants and the uninjured controls were exposed to three concentrations of ozone in transparent mylar chambers; level in ambient air (about 0.025 ppm), 0.06 ppm, or 0.1 ppm. Plants were exposed for 5 h a day for a period of 2-4 d. Ozone exposure at the levels used in this study produced no visible injuries to leaves. Low doses (up to 4-d-exposure to 0.06 ppm or 2-d exposure to 0.1 ppm) of ozone overrode the resistance in soybean that had been induced by the feeding of soybean looper larvae. Higher doses (3- or 4-d exposure to 0.1 ppm) of ozone actually resulted in a greater acceptability by the Mexican bean beetle of plants injured by the soybean looper than of uninjured plants. Doses of ozone used in these experiments did not significantly alter the feeding preference of the Mexican bean beetle for the uninjured plants. Because ozone pollution and herbivore injury are commonly experienced by plants in nature, the results of this study add another perspective to insect-plant interactions.

Lin, Hengchen; Kogan, M. (Univ. of Illinois, Champaign (USA)); Endress, A.G. (Illinois Natural History Survey, Champaign, IL (USA))

1990-08-01

314

Ground-Level Ozone: A Threat to Rice Crop in Muda Irrigation Area of Peninsular Malaysia  

Directory of Open Access Journals (Sweden)

Full Text Available It has long been recognized that pollutant gases cause significant impacts on crops and forests in both developed and developing countries. Ground-level ozone (O3) or better known as tropospheric ozone is recognised as the pollutant most likely to cause widespread crop damage. For this pollutant an AOT40 (accumulative O3 concentration above a threshold of 40 ppb) value causing 5% yield loss for all agricultural crops has been established as 3000 ppb?h, which is applicable during daylight hours over a growing season (UN-ECE, 1996). In order to have a complete estimate of air pollution damage i.e., O3 to paddy plantation area, a dose-response, or yield-loss function have to be developed. In this study, data was gathered from tests in open-top chambers (OTCs), whereby four OTCs were fabricated; two of which were exposed to ambient air pollution (NF) of which ozone is the major perpetrator whilst the remaining were provided with clean air i.e. charcoal filtered air treatment (F). The response of a popular local rice cultivar, MR-219 to current ambient air pollution of which O3 is the overwhelming dominant pollutant was investigated for five successive seasons in Muda Irrigation Scheme Area (MADA); the largest rice growing area in Malaysia. The results of the study clearly indicate that at ozone concentrations even lower than the Malaysian air quality guidelines (60 ppb 8 hr mean) level, there exist a significant impact on the growth and yield of the popular rice cultivar MR-219. Even though weeds, diseases, and insect pests were absent, water and nutrients were in abundance, no adverse soil conditions, and that no extreme weather event such as typhoons occurs; the physiological, growth and development performances of rice plants exposed to ambient ozone were found to be significantly (P< 0.05) reduced by AOT40 compared to control rice plants in filtered chamber. This study discovered that the root was the most significantly affected component of MR-219 rice plant. Meanwhile, reproductive stage is the most vulnerable period of growth to ozone impact followed by grain filling and vegetative stages, respectively.

Marzuki Ismail1, Ahmad Makmom Abdullah2 and Nur Zafirah Mohd Sofian1

2008-01-01

315

Surface ozone trends in Hong Kong in 1985-1995  

Energy Technology Data Exchange (ETDEWEB)

Ozone trends in Hong Kong were assessed from the ozone data recorded at three urban stations and one station in the new development area. Three parameters were selected as the robust trend indicators in the study: monthly mean, monthly averaged daily 1-h maximum, and number of annual hours >120 {mu}g m{sup -3}. As the ozone data displayed obvious seasonal variation, using deseasonalized monthly average parameters to estimate the ozone trends could smooth out the influence of seasonal fluctuations. The detection of an increase of more than 10% per year in ozone concentration at one station was particularly alarming. Effects of meteorological factors, control programmes of ozone precursors, and long-range transport on the ambient ozone level were examined in the study. (Author)

Wu, H.W.Y. [Hong Kong Institute of Vocational Education (China). Dept. of Applied Science; Chan, L.Y. [Hong Kong Polytechnic University (China). Civil and Structural Engineering Dept.

2001-07-01

316

Ozonation of sediments from an urban lake: an exploratory investigation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english An exploratory investigation was conducted on the effects of application of ozone on the removal of organic and inorganic contaminants and the reduction of settleable solids in urban lake sediments. Homogenized sediment samples were treated in a batch reactor with an external recirculation loop and ozone feed from a Venturi injector. The ozone generating system was fed with ambient air with small footprint and operational simplicity. Ozone mass application (g/h) and conta (more) ct 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.

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

2011-09-01

317

Growth at elevated ozone or elevated carbon dioxide concentration alters antioxidant capacity and response to acute oxidative stress in soybean (Glycine max)  

Energy Technology Data Exchange (ETDEWEB)

Soybeans (Glycine max Merr.) were grown at elevated carbon dioxide concentration ([CO{sub 2}]) or chronic elevated ozone concentration ([O{sub 3}]; 90 ppb), and then exposed to an acute O{sub 3} stress (200 ppb for 4 h) in order to test the hypothesis that the atmospheric environment alters the total antioxidant capacity of plants, and their capacity to respond to an acute oxidative stress. Total antioxidant metabolism, antioxidant enzyme activity, and antioxidant transcript abundance were characterized before, immediately after, and during recovery from the acute O{sub 3} treatment. Growth at chronic elevated [O{sub 3}] increased the total antioxidant capacity of plants, while growth at elevated [CO{sub 2}] decreased the total antioxidant capacity. Changes in total antioxidant capacity were matched by changes in ascorbate content, but not phenolic content. The growth environment significantly altered the pattern of antioxidant transcript and enzyme response to the acute O{sub 3} stress. Following the acute oxidative stress, there was an immediate transcriptional reprogramming that allowed for maintained or increased antioxidant enzyme activities in plants grown at elevated [O{sub 3}]. Growth at elevated [CO{sub 2}] appeared to increase the response of antioxidant enzymes to acute oxidative stress, but dampened and delayed the transcriptional response. These results provide evidence that the growth environment alters the antioxidant system, the immediate response to an acute oxidative stress, and the timing over which plants return to initial antioxidant levels. The results also indicate that future elevated [CO{sub 2}] and [O{sub 3}] will differentially affect the antioxidant system.

Gillespie, K.M.; Rogers, A.; Ainsworth, E. A.

2011-01-31

318

Effects of ozone and sulfur dioxide on cotton growth and quality. Final report, 14 September 1083-14 March 1985  

Energy Technology Data Exchange (ETDEWEB)

In a two-year study, two varieties of cotton, Acala SJ-2 and Acala SJC-1, were exposed to SO/sub 2/ and ambient oxidants alone and in combination using open-top field chambers. Two levels of SO/sub 2/, 0.05 ppm and 0.10 ppm were applied for six hours per day, four days per week. SO/sub 2/ at 0.10 ppm reduced yields of SJ-2 cotton in both ambient and filtered air. SO/sub 2/ at 0.10 ppm in combination with ambient oxidants reduced yield of SJC-1 cotton by 16% in the second year. SO/sub 2/ in filtered air did not reduce SJC-1 cotton yield. No changes in cotton quality were observed. Poor growing conditions during the first year and a severe infestation of verticillium, a soil borne fungal disease, during the second year may have obscured the impact of air pollution on yields.

Brewer, R.F.

1985-01-15

319

Genes of innate immunity and the biological response to inhaled ozone.  

UK PubMed Central (United Kingdom)

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 noninfectious 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 noninfectious airways disease. In this brief review, we focus on (1) specific cell types in the lung modified by ozone, (2) ozone and oxidative stress, (3) the relationship between genes of innate immunity and ozone, (4) the role of extracellular matrix in reactive airways disease, and (5) the effect of ozone on the adaptive immune system. We summarize recent advances in understanding the mechanisms that ozone contributes to environmental airways disease.

Li Z; Tighe RM; Feng F; Ledford JG; Hollingsworth JW

2013-01-01

320

Ozone-induced increase in bean leaf maintenance respiration  

Energy Technology Data Exchange (ETDEWEB)

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

Amthor, J.S.

1987-01-01

 
 
 
 
321

Remote measurements of ozone concentration and aerosols in the Arctic stratosphere  

Energy Technology Data Exchange (ETDEWEB)

A LIDAR instrument for measurements of the ozone concentration and of aerosols in the middle atmosphere is briefly described. Data sets for ozone and aerosols, obtained at Spitsbergen during winter and early spring in 1989 and 1990, are presented. The Arctic ozone layer was found to be strongly influenced by atmospheric dynamics; a dramatic ozone depletion was not observed. Polar stratospheric clouds were detected in each winter, their dependence on the ambient atmospheric temperature is described. (orig.).

Neuber, R.; Schrems, O. (Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany, F.R.)); Krueger, B.C. (Bremen Univ. (Germany, F.R.))

1991-08-01

322

Compilation of photochemical models` performance statistics for 11/94 ozone SIP applications. Final report  

Energy Technology Data Exchange (ETDEWEB)

This report is a compilation of the model performance statistics of three photochemical models (UAM-IV, UAM-V, and SAQM) used in the 11/94 Ozone State Implementation Plans (SIP) applications. The models were applied in 24 ozone nonattainment regions in 1993-1995 to support the development of emissions control strategies for the 1994 ozone SIPs. The evaluation focuses on three EPA recommended basic model performance statistical measures of the models` ability to predict ambient ozone concentrations.

NONE

1996-07-01

323

Ozone depletion zone and ozone smog. Ozone chemistry fundamentals  

International Nuclear Information System (INIS)

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

1994-01-01

324

Source apportionment of ambient volatile organic compounds in Beijing.  

Science.gov (United States)

The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing. PMID:17626435

Song, Yu; Shao, Min; Liu, Ying; Lu, Sihua; Kuster, William; Goldan, Paul; Xie, Shaodong

2007-06-15

325

Source apportionment of ambient volatile organic compounds in Beijing.  

UK PubMed Central (United Kingdom)

The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing.

Song Y; Shao M; Liu Y; Lu S; Kuster W; Goldan P; Xie S

2007-06-01

326

Issues on urban ozone: Natural hydrocarbons, urbanization and ozone control strategies  

Energy Technology Data Exchange (ETDEWEB)

Using the Atlanta metropolitan area as a case study, the author has examined the effects of urbanization and its associated heat island on urban ozone concentrations. As cities grow, two important effects take place: the amount of trees is reduced and there is an increase in ambient temperature due to the urban heat island effect. As the temperature increases, more ozone is photochemically produced, more anthropogenic hydrocarbons are released into the atmosphere, and more biogenic hydrocarbons are emitted from the remaining trees. This increase in hydrocarbons helps produce even more ozone. Numerical simulations using conditions of a typical summertime day in Atlanta suggest that these processes are able to offset the reductions in anthropogenic hydrocarbon emissions caused by emission controls. To study ozone control strategies, the author has developed a photochemical model that utilizes ozone and ozone precursors observations as input data, and is therefore independent of the highly uncertain processes of emission inventories and transport. In contrast with the operation of the current emission-based models, the observation-based model (OBM) is relatively easy to implement and very fast to operate. Using numerical simulations of different meteorological and chemical conditions in Atlanta, he has shown that the ozone sensitivities obtained with the observation-based model, are in very good agreement with similar ozone sensitivities derived using an emission-based model that includes transport. He also illustrated the potential utility of the OBM by applying it to the ozone non-attainment problem in Baton Rouge, Louisiana.

Cardelino, C.A.

1991-01-01

327

Ozone Pollution  

Medline Plus

Full Text Available ... Protect Yourself Take Action Join Our Fight For Air Donate Share Your Story Share Your Air Shop For Air Send an eCard Download Report Or Or Enter ... atoms. It is the primary ingredient of smog air pollution and is very harmful to breathe. Ozone ...

328

Ozone Pollution  

Medline Plus

Full Text Available ... 2012 > Health Risks Health Risks Ozone Particle Pollution Children's Health Disparities Near Highways Protect Yourself Take Action Join ... into data from their long-term Southern California Children’s Health Study found that some children with certain genes ...

329

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

330

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

2009-01-01

331

Comparative study of ozonized olive oil and ozonized sunflower oil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 juntamente com a atividade antimicrobiana. Os efeitos da ozonização na composição dos ácidos graxos desses óleos foram analisados usando-se a técnica de Cromatografia (more) 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 acid (more) ity 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.

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

2006-04-01

332

Ozone tolerance of European larch (Larix decidua Mill.)  

International Nuclear Information System (INIS)

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

1993-01-01

333

A passive sampler for atmospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-02-01

334

A passive sampler for atmospheric ozone  

International Nuclear Information System (INIS)

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

1992-01-01

335

Effect of foliage surface wetness on the deposition of ozone  

Energy Technology Data Exchange (ETDEWEB)

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

Fuentes, J.D.

1992-01-01

336

Second year effects of clouds and ozone on red spruce seedlings  

Energy Technology Data Exchange (ETDEWEB)

Potted native and phyton-grown red spruce seedlings were exposed for a second growing season to ozone and/or acid deposition in open-top field chambers on Whitetop Mountain, VA (elevation 1,680 m). Chamber treatments were (1) exclusion of clouds and 50% reduction in ambient ozone (COE), (2) ozone with clouds excluded (CE), and (3) exposure to clouds and ozone, as control chambers (CO), and (4) open plots (AA). No differences were detected among treatments for biomass accumulation or for chlorophyll and carotenoid concentrations. Phyton seedlings in AA and CO treatments maintained high photosynthetic rates through October, whereas rates in CE and COE decreased, suggesting that dormancy and winter hardiness were delayed in AA and CO, possibly making seedlings susceptible to early frosts. Respiration of both seedling types was higher for AA and CO throughout most of the growing season, which could lead to depletion of carbohydrates, and eventually to a reduction in growth and vigor of the seedlings over time due to air pollution.

Pier, P.A.; Thornton, F.C.; McDuffie, C. Jr. (Tennessee Valley Authority, Muscle Shoals, AL (USA))

1990-05-01

337

Ozone Pollution  

Medline Plus

Full Text Available ... city in the nation to install an air quality warning flag system on the beach. 22 How ... Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: Act Locally What You ...

338

Ozone Pollution  

Medline Plus

Full Text Available ... for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: Act Locally What You Can ... Progress but Challenges Remain Cleaner Gasoline and Vehicle Standards Would Yield Major Health Benefits Senator Frank Lautenberg: ...

339

MOVPE growth of Al-free 808 nm high power lasers using TBP and TBA in pure N2 ambient  

Science.gov (United States)

In metalorganic vapor-phase epitaxy (MOVPE) growth of III V semiconductor compounds and device structures, arsine (AsH3) and phosphine (PH3) are normally used as group V precursors and hydrogen is used as the carrier gas, which is very toxic and has safety hazard. In this contribution, MOVPE growths of Al-free 808 nm high power diode lasers by using metalorganic (MO) group V sources, TBAs and TBP, and nitrogen as carrier gas has been reported. InGaAsP/InGaP/GaAs single quantum well (SQW) high power laser structure emitting at 808 nm has been adopted to characterize the material quality. Broad area stripe lasers with the stripe width of 150 ?m have been fabricated from the wafers grown by the MOVPE using MO group V sources. Lasing of the device with threshold current density of 506 A/cm2 has been successfully achieved.

Tang, Xiaohong; Zhang, Baolin; Bo, Baoxue; Mei, Ting; Chin, Mee-Koy

2006-02-01

340

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

UK PubMed Central (United Kingdom)

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.

Connan S; Stengel DB

2011-07-01

 
 
 
 
341

Plant species sensitivity distributions for ozone exposure.  

Science.gov (United States)

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. PMID:23501341

van Goethem, T M W J; Azevedo, L B; van Zelm, R; Hayes, F; Ashmore, M R; Huijbregts, M A J

2013-03-19

342

Plant species sensitivity distributions for ozone exposure.  

UK PubMed Central (United Kingdom)

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.

van Goethem TM; Azevedo LB; van Zelm R; Hayes F; Ashmore MR; Huijbregts MA

2013-07-01

343

Effects of ozone on crops in north-west Pakistan.  

UK PubMed Central (United Kingdom)

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.

Ahmad MN; Büker P; Khalid S; Van Den Berg L; Shah HU; Wahid A; Emberson L; Power SA; Ashmore M

2013-03-01

344

Stratospheric ozone depletion  

Energy Technology Data Exchange (ETDEWEB)

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

NONE

1999-07-01

345

Ozone crisis  

Energy Technology Data Exchange (ETDEWEB)

The author presents an account of the depletion of the atmosphere's ozone layer since the discovery of the phenomenon 15 years ago. The book recounts the flight to ban chlorofluorocarbons (CFC's) and describes the science, the people, and the politics involved, up to the March 1988 international treaty restricting CFC production. It surveys the media's coverage, describes the struggle for remedies, and offers a prognosis for the future.

Roan, S.

1989-01-01

346

Ozone influence on native vegetation in the Jizerske hory Mts. of the Czech Republic: results based on ozone exposure and ozone-induced visible symptoms.  

Science.gov (United States)

Ozone levels in the Jizerske hory Mts. measured at 13 sites by diffusive samplers during the 2006 and 2007 vegetation seasons are presented. A significant ozone gradient (5.4 ppb in 2006 and 4.0 ppb in 2007) per 100 m difference in altitude between 370 and 1,100 m a.s.l. was recorded. High-resolution maps of phytotoxic potential were developed. The AOT40 threshold (5 ppm h) was exceeded over the entire area with the highest levels exceeding this threshold by 12 times in the upper portions of the mountains. Ozone visible injury was evaluated at four of the monitoring sites on seven native plant and tree species. Four species showed ozone-like symptoms, two of which (Rubus idaeus and Fagus sylvatica) were confirmed as ozone-induced. Our results indicate that ambient ozone is likely to have a much lower impact on the Jizerske hory Mts. vegetation than expected, considering the measured ambient ozone exposures and favourable environmental conditions for ozone uptake. PMID:21374050

H?nová, Iva; Matoušková, Leona; Srn?nský, Radek; Koželková, Klára

2011-03-04

347

Ozone influence on native vegetation in the Jizerske hory Mts. of the Czech Republic: results based on ozone exposure and ozone-induced visible symptoms.  

UK PubMed Central (United Kingdom)

Ozone levels in the Jizerske hory Mts. measured at 13 sites by diffusive samplers during the 2006 and 2007 vegetation seasons are presented. A significant ozone gradient (5.4 ppb in 2006 and 4.0 ppb in 2007) per 100 m difference in altitude between 370 and 1,100 m a.s.l. was recorded. High-resolution maps of phytotoxic potential were developed. The AOT40 threshold (5 ppm h) was exceeded over the entire area with the highest levels exceeding this threshold by 12 times in the upper portions of the mountains. Ozone visible injury was evaluated at four of the monitoring sites on seven native plant and tree species. Four species showed ozone-like symptoms, two of which (Rubus idaeus and Fagus sylvatica) were confirmed as ozone-induced. Our results indicate that ambient ozone is likely to have a much lower impact on the Jizerske hory Mts. vegetation than expected, considering the measured ambient ozone exposures and favourable environmental conditions for ozone uptake.

H?nová I; Matoušková L; Srn?nský R; Koželková K

2011-12-01

348

Effects of ozone and ultraviolet-B radiation, alone and in combination, on growth of cucumber plants  

Energy Technology Data Exchange (ETDEWEB)

Cucumber plants were exposed to 0.10, 0.15, or 0.20{mu}l{center_dot}L{sup -1}O3 and UV radiation (190mW{center_dot}m{sup -2}UV-B{sub BE}), alone and in combination, for 6 hrs/a day, 6 times during an exposure period of 15 days from the 7th to the 21st day after sowing. The effects of relatively low concentrations of O3 and UV-B radiation on the growth of cucumber plants are investigated, alone and in combination. The dry weight growth of cucumber plants was not affected by the single exposure to O3 at 0.10{mu}l{center_dot}L{sup -1}. However, single exposure to O3 at 0.15 or 0.20{mu}l{center_dot}L{sup -1} caused the reductions in the areal growth of leaves and dry weight growth of the plants. The most important result obtained was that there were significant interactive effects of O3 at 0.15 or 0.20{mu}l{center_dot}L{sup -1} and UV radiation at 190mW{center_dot}m{sup -2}UV-B{sub BE} on the growth of cucumber plants. The degree of reduction in the dry weight growth of the plants simultaneously exposed to O3 and UV radiation was greater than that of the plants exposed to O3 or UV radiation alone. 36 refs., 1 fig., 5 tabs.

Izuta, T.; Takahashi, S.; Aoki, M.; Totsuka, T. [Tokyo Univ. of Agriculture and Technology, Fuchu (Japan). Faculty of Agriculture

1995-03-10

349

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1983-10-01

350

Atmospheric particulate matter and ozone under heat-wave conditions: do they cause an increase of mortality in Croatia?  

UK PubMed Central (United Kingdom)

In August 2003 Croatia experienced a heat-wave period during which elevated concentrations of particulate matter (PM10) and ozone in ambient air were measured. By applying the model of Stedman and Rooney et al., it was shown that a significant part of excess mortality during this period can be attributed to PM10 and ozone in ambient air.

Alebi?-Jureti? A; Cvitas T; Kezele N; Klasinc L; Pehnec G; Sorgo G

2007-10-01

351

Atmospheric particulate matter and ozone under heat-wave conditions: do they cause an increase of mortality in Croatia?  

Science.gov (United States)

In August 2003 Croatia experienced a heat-wave period during which elevated concentrations of particulate matter (PM10) and ozone in ambient air were measured. By applying the model of Stedman and Rooney et al., it was shown that a significant part of excess mortality during this period can be attributed to PM10 and ozone in ambient air. PMID:17653503

Alebi?-Jureti?, Ana; Cvitas, Tomislav; Kezele, Nenad; Klasinc, Leo; Pehnec, Gordana; Sorgo, Glenda

2007-07-25

352

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

Directory of Open Access Journals (Sweden)

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

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

2009-01-01

353

Plant-atmosphere interactions and effects of elevated carbon dioxide on growth and photosynthesis of black cottonwood at ambient and optimal nutrient supply  

Energy Technology Data Exchange (ETDEWEB)

In 1990 a 14 ha stand of black cottonwood was planted on an exposed site in Gunnarsholt in south Iceland to investigate the long-term modification of microclimate as tree canopy develops on an exposed site and the effects of microclimate on tree physiology and growth. The homogenous treeless surroundings of the site provide excellent fetch and meet the most stringent criteria of energy balance models. Site energy balance is partitioned using the Bowen ratio approach based on data from both a reversing temperature difference measurement system and a fixed profile system. Key characteristics of the site energy balance and microclimate will be presented. In the beginning of the 1994 growing season a five-year study of the interaction between nutrient supply and elevated carbon dioxide was initiated using sixteen trees enclosed individually in chambers and given either 350 or 700 ppm carbon dioxide and either ambient or optimum nutrition in a randomized block design. Reference trees are used to determine the effect of the chambers which is significant on exposed sites due to sheltering effects. Growth of the trees was monitored non-destructively. Photosynthetic rates, light response and A/C{sub i} curves were determined on selected leaves. Examples of results from the first growing season will be presented.

Thorgeirsson, H.; Sigurdsson, B.D. [Agricultural Research Institute, Reykjavik (Iceland)

1995-06-01

354

Growth responses of male broilers subjected to increasing air velocities at high ambient temperatures and a high dew point.  

Science.gov (United States)

This study examined live performance responses of male broilers to increasing air velocity of 120 and 180 m/min reared under high cyclic temperatures (25-35-25 degrees C) with a 23 degrees C dew point from 21 to 49 d. Birds were reared in an environmental facility containing 2 wind tunnels (4 pens/tunnel) and 6 floor pens (control). At 21 d, 53 birds were placed in each pen of the wind tunnels and control group, respectively, and growth performance was determined weekly. Increasing air velocity from 120 to 180 m/min improved BW and BW gain from 29 to 35, 36 to 42, and 43 to 49 d of age leading to a cumulative advantage of 287 g in BW gain and a 10-point difference in feed conversion from 21 to 49 d of age. Subjecting birds to air velocity improved growth rate, feed consumption, and feed conversion at each weekly interval from 28 to 49 d over the control birds. These results indicate that male broilers approximating 2.0 to 3.0 kg respond to an air velocity of 180 m/min when exposed to high cyclic temperatures. PMID:15971539

Dozier, W A; Lott, B D; Branton, S L

2005-06-01

355

Growth responses of male broilers subjected to increasing air velocities at high ambient temperatures and a high dew point.  

UK PubMed Central (United Kingdom)

This study examined live performance responses of male broilers to increasing air velocity of 120 and 180 m/min reared under high cyclic temperatures (25-35-25 degrees C) with a 23 degrees C dew point from 21 to 49 d. Birds were reared in an environmental facility containing 2 wind tunnels (4 pens/tunnel) and 6 floor pens (control). At 21 d, 53 birds were placed in each pen of the wind tunnels and control group, respectively, and growth performance was determined weekly. Increasing air velocity from 120 to 180 m/min improved BW and BW gain from 29 to 35, 36 to 42, and 43 to 49 d of age leading to a cumulative advantage of 287 g in BW gain and a 10-point difference in feed conversion from 21 to 49 d of age. Subjecting birds to air velocity improved growth rate, feed consumption, and feed conversion at each weekly interval from 28 to 49 d over the control birds. These results indicate that male broilers approximating 2.0 to 3.0 kg respond to an air velocity of 180 m/min when exposed to high cyclic temperatures.

Dozier WA 3rd; Lott BD; Branton SL

2005-06-01

356

Salud y medio ambiente: Health and environment  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Motivado por la importancia del control del medio ambiente se realiza un panel con los estudiantes de la especialidad de Tecnología de la Salud en el municipio de Matanzas, con el objetivo de fomentar en estos una conciencia ambientalista y de esta forma sensibilizar a los mismos, para ser defensores 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 (more) 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 raising 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 (more) 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.

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

2009-10-01

357

Salud y medio ambiente: Health and environment  

Directory of Open Access Journals (Sweden)

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 defensores 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 .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 raising 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

2009-01-01

358

Secondary maxima in ozone profiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone profiles from balloon soundings as well as SAGE II ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Ross...

Lemoine, R.

359

Secondary maxima in ozone profiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone profiles from balloon soundings as well as SAGEII ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossb...

Lemoine, R.

360

Response of Federal Land Management Agencies to ozone impacts on vegetation  

Energy Technology Data Exchange (ETDEWEB)

The FLAG (Federal Land Manager's AQRV WorkGroup) Ozone Subgroup was organized to compile information known about response of vegetation to ozone in federally managed parks, forests, and wildlife refuges; to document areas of agreement among federal agencies regarding identification of ozone sensitive Air Quality Related Values (AQRVs); and standardize agency responses to New Source Review (NSR) permit applications. Subgroup members included air resource managers and ozone effects scientists from several agencies that manage federal lands. The subgroup identified sensitive AQRV receptors, determined information needed to evaluate permit applications under the NSR process, determined the form of an ozone parameter to use to relate plant response to ambient ozone, and agreed on specific definitions for vegetation injury and damage from ozone. The subgroup developed specific protocols for federal agencies to follow in response to NSR permit applications. These protocols were based on (1) ambient levels of ozone as measured by the W126 ozone metric and the number of peak ozone concentrations $100 ppb (N100), and (2) the presence or absence of ozone sensitive plant species and ozone-induced damage to vegetation.

Musselman, R.C.; Fisher, R.W.

1999-07-01

 
 
 
 
361

Ozone exaggerates nasal allergic inflammation.  

UK PubMed Central (United Kingdom)

(Full text is available at http://www.manu.edu.mk/prilozi). A double-blind randomised trail design was used to address the effect of ambient ozone on the nasal airways and to evaluate the effects of ozone on allergic mucosa. Ten grass pollen allergic rhinitics were exposed for 2 hours at rest on 2 separate occasions to 400 ppb ozone and filtered air respectively. The exposure to 400 ppb ozone and filtered air was performed prior to the grass pollen season and again during the season. Baseline nasal lavage in which histamine, eosinophil cationic protein (ECP), myeloperoxidase (MPO), total proteins, and albumin were measured and neutrophils, eosinophils and epithelial cells were counted, was made immediately prior to exposure (-120 min). After 2h of exposure to ozone/filtered air repeated measurements were performed at 0, 30, 60, 120, 240, 360 minutes post exposure. Significant increases were observed when exposed to ozone versus filtered air during the pollen season for histamine (AUC1; p = 0.05), MPO (AUC2; p = 0.05), ECP (AUC2; p = 0.008), total proteins (AUC, p = 0.02; AUC1, p = 0.007; AUC2, p = 0.05), and albumin (AUC, p = 0.007; AUC1, p = 0.02; AUC2, p = 0.005). There was also a significant increase in the total protein level (AUC, p = 0.05; AUC1, p = 0.02; AUC2 p = 0.05) and albumin (AUC, p = 0.03; AUC1, p = 0.03; AUC2, p = 0.04) after ozone exposure versus air out of season. Significant increase of the neutrophils (p = 0.01 and p = 0.007) in the nasal lavage fluid (NLF) at time points 0 min and 360 min respectively were observed, while eosinophils and epithelial cells significantly increased only at time point 360 min (p = 0.02 and p = 0.02 respectively) all of them after ozone exposure versus filtered air during the season. Neutrophils also significantly increased in the NLF at time point 0 min and 360 min (p = 0.03 and p = 0.01) while epithelial cells increased only at time point 360 min (p = 0.01) after ozone exposure versus filtered air out of season. We can conclude that ozone induces neutrophil and eosinophil recruitment into the nose and this is accom-panied by activation, as evidenced by release of MPO and ECP in NAL. Pre-existing allergic mucosal inflam-mation during the pollen season, exaggerates the response to ozone, particularly in relationship to the re-cruitment of eosinophils and neutrophils 6h following exposure. Key words: mediators, allergic rhinitis, ozone.

Dokic D; Trajkovska-Dokic E

2013-01-01

362

Ozone disintegration kinetics in the reactor for tyres decomposition  

International Nuclear Information System (INIS)

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

2010-01-01