Elevated levels of environmental ozone and their effects on the lung function in selected collectives of the population

International Nuclear Information System (INIS)

Hoeppe, P.; Lindner, J.; Praml, G.; Broenner, N.

1993-01-01

Lung function parameters (measured with a bodyplethysmograph) and subjective votes on complaints and irritations are taken on location from 200 subjects where they spend the daytime. The subjects belong to five collectives of equal size consisting of four assumed ozone risk groups (senior citizens, juvenile asthmatics, forestry workers and athletes) and a control group (clerks). Every subject is examined one eight days both in the morning and in the afternoon - the objective is to obtain an equal distribution of measuring days with elevated ozone concentrations (max. half hour mean values between 1 p.m. and 4 p.m. at least 100 μg/m 3 ) and low ozone concentrations (max. half hour mean values between 1 and 4 p.m. at most 80 μg/m 3 ) for every subject. At present the measurements of the 'senior citizens' are completed and the first results are evaluated. They show no relevant acute ozone effect as far as the lung function parameters or the subjective votes on irritations are concerned. Thus there is no indication that senior citizens represent a particular risk group in respect to moderately elevated levels of environmental ozone, as they occur in Central Europe. (orig.) [de

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

Data.gov (United States)

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

Cardiopulmonary Mortalities and Chronic Obstructive Pulmonary Disease Attributed to Ozone Air Pollution

Directory of Open Access Journals (Sweden)

Gholamreza Goudarzi

2013-07-01

Full Text Available Background & Aims of the Study: Ozone is a summer pollutant which can cause respiratory complications, eye burning sensation and failure of immune defense against infectious diseases. Ahvaz city (southwestern Iran is one of the seven polluted Iranian metropolises. In this study we examined the health impacts of ozone pollution in Ahvaz city during years 2010 and 2011. Materials & Methods: The health effects of ozone pollution in Ahvaz estimated by determining mortality and morbidity, and incidence of diseases attributed to the ozone, i.e., cardiopulmonary mortalities and chronic obstructive pulmonary disease (COPD using Air Quality Model. Ozone data were taken from Ahvaz Department of Environment (ADoE. Conversion between volumetric and gravimetric units (correction of temperature and pressure, coding, processing (averaging and filtering were implemented. Results: Sum of accumulative cases of mortalities attributed to ozone was 358 cases in 2010 and 276 cases in 2011. Cardiovascular and respiratory mortality attributed to ozone were 118 and 31 persons, respectively; which revealed a considerable reduction compared to those values in 2010. Number of cases for hospital admissions due to COPD was 35 in 2011, while it was 45 cases in 2010. The concentration of ozone in 2011 was lower than that of 2010 and this is why both mortalities and morbidities of 2011 attributed to ozone pollutant had decreased when compared to those values of 2010. Conclusions: Mortality and morbidity attributed to ozone concentrations in 2011 were lower than those of 2010. The most important reason was less concentration in ground level ozone of 2011 than that of 2010 in Ahvaz city air.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Elevated CO{sub 2} does not ameliorate effects of ozone on carbon allocation in Pinus halepensis and Betula pendula in symbiosis with Paxillus involutus

Energy Technology Data Exchange (ETDEWEB)

Kytoeviita, M.M. [Oulu Univ., Dept. of Biology, Oulu (Finland); Pelloux, J.; Fontaine, V.; Botton, B.; Dizengremel, P. [Univ. Henri Poincare-Nancy, Lab. de Biologie Forestiere Associe INRA, Vandoeuvre-les-Nancy (France)

1999-07-01

The effect of 700 {mu}mol CO{sub 2} mol{sup -1}, 200 nmol ozone mol{sup -1} and a combination of the two on carbon allocation was examined in Pinus halepensis co-cultured with Betula pendula in symbiosis with the ectomycorrhizal fungus Paxillus involutus. The results show that under low nutrient and ozone levels, elevated CO{sub 2} has no effect on the growth of B. pendula or P. halepensis seedlings nor on net carbon partitioning between plant parts. Elevated CO{sub 2} did not enhance the growth of the fungus in symbiosis with the birch. On the other hand, ozone had a strong negative effect on the growth of the birch, which corresponded with the significantly reduced growth rates of the fungus. Exposure to elevated CO{sub 2} did not ameliorate the negative effects of ozone on birch; in contrast, it acted as an additional stress factor. Neither ozone nor CO{sub 2} had significant effects on biomass accumulation in the pine seedlings. Ozone stimulated the spread of mycorrhizal infection from the birch seedlings to neighbouring pines and had no statistically significant effects on phosphoenolpyruvate carboxylase (PEPC) or ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity in the pine needles or on PEPC activity in pine roots. (au)

Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

Science.gov (United States)

Alan F. Talhelm; Kurt S. Pregitzer; Mark E. Kubiske; Donald R. Zak; Courtney E. Campany; Andrew J. Burton; Richard E. Dickson; George R. Hendrey; J. G. Isebrands; Keith F. Lewin; John Nagy; David F. Karnosky

2014-01-01

Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment...

Effects Of Elevated Ozone On Leaf {delta} {sup 13} C And Leaf Conductance Of Plant Species Grown In Semi-Natural Grassland With Or Without Irrigation

Energy Technology Data Exchange (ETDEWEB)

Jaeggi, M.; Saurer, M.; Volk, M. [Agroscope-FAL (Switzerland); Fuhrer, J. [Agroscope-FAL (Switzerland)

2005-03-01

At the Swiss prealpine site Le Mouret (754 m a.s.l. 46deg 45min N / 7deg 10min E), semi-natural grassland species were kept under ambient or elevated ozone, paired with or without additional irrigation. Two of the four investigated grassland species showed an additive increase in {sup 13}C-values under drought and elevated ozone conditions. (author)

Elevated ozone negatively affects photosynthesis of current-year leaves but not previous-year leaves in evergreen Cyclobalanopsis glauca seedlings

International Nuclear Information System (INIS)

Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Niu, Junfeng

2014-01-01

To assess the effects of leaf age/layer on the response of photosynthesis to chronic ozone (O 3 ), Cyclobalanopsis glauca seedlings, a dominant evergreen broadleaf tree species in sub-tropical regions, were exposed to either ambient air (AA) or elevated O 3 (AA + 60 ppb O 3 , E-O 3 ) for two growing seasons in open-top chambers. Chlorophyll content, gas exchange and chlorophyll a fluorescence were investigated three times throughout the 2nd year of O 3 exposure. Results indicated that E-O 3 decreased photosynthetic parameters, particularly light-saturated photosynthesis rate, stomatal conductance and effective quantum yield of PSII photochemistry of current-year leaves but not previous-year leaves. Stomatal conductance of plants grown under ambient conditions partially contributed to the different response to E-O 3 between leaf layers. Light radiation or other physiological and biochemical processes closely related to photosynthesis might play important roles. All suggested that leaf ages or layers should be considered when assessing O 3 risk on evergreen woody species. -- Highlights: • Response of evergreen Cyclobalanopsis glauca to O 3 was investigated. • Elevated O 3 significantly reduced photosynthesis of current-year leaves. • Previous-year leaves showed little response to O 3 . • Stomatal conductance contributes to the response difference to O 3 among leaf ages. -- Impacts of elevated O 3 on photosynthesis of evergreen woody species depend on leaf ages

Can elevated CO2 and ozone shift the genetic composition of aspen (Populus tremuloides) stands? New Phytologist

Science.gov (United States)

Emily V. Moran; Mark E. Kubiske

2013-01-01

The world's forests are currently exposed to increasing concentrations of carbon dioxide (CO2) and ozone (O3). Both pollutants can potentially exert a selective effect on plant populations. This, in turn, may lead to changes in ecosystem properties, such as carbon sequestration. Here, we report how elevated CO

Effects of ozone on crops in north-west Pakistan

International Nuclear Information System (INIS)

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

2013-01-01

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

Process-scale modeling of elevated wintertime ozone in Wyoming.

Energy Technology Data Exchange (ETDEWEB)

Kotamarthi, V. R.; Holdridge, D. J.; Environmental Science Division

2007-12-31

Measurements of meteorological variables and trace gas concentrations, provided by the Wyoming Department of Environmental Quality for Daniel, Jonah, and Boulder Counties in the state of Wyoming, were analyzed for this project. The data indicate that highest ozone concentrations were observed at temperatures of -10 C to 0 C, at low wind speeds of about 5 mph. The median values for nitrogen oxides (NOx) during these episodes ranged between 10 ppbv and 20 ppbv (parts per billion by volume). Measurements of volatile organic compounds (VOCs) during these periods were insufficient for quantitative analysis. The few available VOCs measurements indicated unusually high levels of alkanes and aromatics and low levels of alkenes. In addition, the column ozone concentration during one of the high-ozone episodes was low, on the order of 250 DU (Dobson unit) as compared to a normal column ozone concentration of approximately 300-325 DU during spring for this region. Analysis of this observation was outside the scope of this project. The data analysis reported here was used to establish criteria for making a large number of sensitivity calculations through use of a box photochemical model. Two different VOCs lumping schemes, RACM and SAPRC-98, were used for the calculations. Calculations based on this data analysis indicated that the ozone mixing ratios are sensitive to (a) surface albedo, (b) column ozone, (c) NOx mixing ratios, and (d) available terminal olefins. The RACM model showed a large response to an increase in lumped species containing propane that was not reproduced by the SAPRC scheme, which models propane as a nearly independent species. The rest of the VOCs produced similar changes in ozone in both schemes. In general, if one assumes that measured VOCs are fairly representative of the conditions at these locations, sufficient precursors might be available to produce ozone in the range of 60-80 ppbv under the conditions modeled.

Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches

International Nuclear Information System (INIS)

Manninen, S.; Huttunen, S.; Vanhatalo, M.; Pakonen, T.; Haemaelaeinen, A.

2009-01-01

We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O 3 ) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O 3 , i.e. O 3 levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O 3 and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels. - Northern birches are responsive to ambient ozone levels.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-09-01

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

Chemical composition and digestibility of Trifolium exposed to elevated ozone and carbon dioxide in a free-air (FACE) fumigation system

Science.gov (United States)

R.B. Muntifering; A.H. Chappelka; J.C. Lin; D.F. Karnosky; G.L. Somers

2006-01-01

Tropospheric ozone (O3) and carbon dioxide (CO2) are significant drivers of plant growth and chemical composition. We hypothesized that exposure to elevated concentrations of O3 and CO2, singly and in combination, would modify the chemical composition of Trifolium...

Elevated gamma-aminobutyric acid levels in chronic schizophrenia.

Science.gov (United States)

Ongür, Dost; Prescot, Andrew P; McCarthy, Julie; Cohen, Bruce M; Renshaw, Perry F

2010-10-01

Despite widely replicated abnormalities of gamma-aminobutyric acid (GABA) neurons in schizophrenia postmortem, few studies have measured tissue GABA levels in vivo. We used proton magnetic resonance spectroscopy to measure tissue GABA levels in participants with schizophrenia and healthy control subjects in the anterior cingulate cortex and parieto-occipital cortex. Twenty-one schizophrenia participants effectively treated on a stable medication regimen (mean age 39.0, 14 male) and 19 healthy control subjects (mean age 36.3, 12 male) underwent a proton magnetic resonance spectroscopy scan using GABA-selective editing at 4 Tesla after providing informed consent. Data were collected from two 16.7-mL voxels and analyzed using LCModel. We found elevations in GABA/creatine in the schizophrenia group compared with control subjects [F(1,65) = 4.149, p = .046] in both brain areas (15.5% elevation in anterior cingulate cortex, 11.9% in parieto-occipital cortex). We also found a positive correlation between GABA/creatine and glutamate/creatine, which was not accounted for by % GM or brain region. We found elevated GABA/creatinine in participants with chronically treated schizophrenia. Postmortem studies report evidence for dysfunctional GABAergic neurotransmission in schizophrenia. Elevated GABA levels, whether primary to illness or compensatory to another process, may be associated with dysfunctional GABAergic neurotransmission in chronic schizophrenia. Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

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

International Nuclear Information System (INIS)

McGrath, Justin M.; Karnosky, David F.; Ainsworth, Elizabeth A.

2010-01-01

Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO 2 ]) and elevated ozone concentration ([O 3 ]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO 2 ] and [O 3 ] predicted for ∼2050. The responses of two clones were compared during the first month of spring leaf out when CO 2 fumigation had begun, but O 3 fumigation had not. Trees in elevated [CO 2 ] plots showed a stimulation of leaf area index (36%), while trees in elevated [O 3 ] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO 2 ], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO 2 ]; however, the two clones responded differently to long-term growth at elevated [O 3 ]. The O 3 -sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O 3 ] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O 3 ] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O 3 ], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO 2 ] and suppressed by elevated [O 3 ] in aspen (Populus tremuloides).

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

Directory of Open Access Journals (Sweden)

Erika Rodríguez-Martínez

2016-10-01

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

Ozone uptake (flux) as it relates to ozone-induced foliar symptoms of Prunus serotina and Populus maximowizii x trichocarpa

International Nuclear Information System (INIS)

Orendovici-Best, T.; Skelly, J.M.; Davis, D.D.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E.

2008-01-01

Field studies were conducted during 2003 and 2004 from early June to the end of August, at 20 sites of lower or higher elevation within north-central Pennsylvania, using seedlings of black cherry (Prunus serotina, Ehrh.) and ramets of hybrid poplar (Populus maximowizii x trichocarpa). A linear model was developed to estimate the influence of local environmental conditions on stomatal conductance. The most significant factors explaining stomatal variance were tree species, air temperature, leaf vapor pressure deficit, elevation, and time of day. Overall, environmental factors explained less than 35% of the variation in stomatal conductance. Ozone did not affect gas exchange rates in either poplar or cherry. Ozone-induced foliar injury was positively correlated with cumulative ozone exposures, expressed as SUM40. Overall, the amount of foliar injury was better correlated to a flux-based approach rather than to an exposure-based approach. More severe foliar injuries were observed on plants growing at higher elevations. - Within heterogeneous environments, ozone flux does not completely explain the variation observed in ozone-induced visible injury

Growth, yield and quality attributes of a tropical potato variety (Solanum tuberosum L. cv Kufri chandramukhi) under ambient and elevated carbon dioxide and ozone and their interactions.

Science.gov (United States)

Kumari, Sumita; Agrawal, Madhoolika

2014-03-01

The present study was designed to study the growth and yield responses of a tropical potato variety (Solanum tuberosum L. cv. Kufri chandramukhi) to different levels of carbon dioxide (382 and 570ppm) and ozone (50 and 70ppb) in combinations using open top chambers (OTCs). Plants were exposed to three ozone levels in combination with ambient CO2 and two ozone levels at elevated CO2. Significant increments in leaf area and total biomass were observed under elevated CO2 in combination with ambient O3 (ECO2+AO3) and elevated O3 (ECO2+EO3), compared to the plants grown under ambient concentrations (ACO2+AO3). Yield measured as fresh weight of potato also increased significantly under ECO2+AO3 and ECO2+EO3. Yield, however, reduced under ambient (ACO2+AO3) and elevated ozone (ACO2+EO3) compared to ACO2 (filtered chamber). Number, fresh and dry weights of tubers of size 35-50mm and>50mm used for direct consumption and industrial purposes, respectively increased maximally under ECO2+AO3. Ambient as well as elevated levels of O3 negatively affected the growth parameters and yield mainly due to reductions in number and weight of tubers of sizes >35mm. The quality of potato tubers was also modified under different treatments. Starch content increased and K, Zn and Fe concentrations decreased under ECO2+AO3 and ECO2+EO3 compared to ACO2+AO3. Starch content reduced under ACO2+AO3 and ACO2+EO3 treatments compared to ACO2. These results clearly suggest that elevated CO2 has provided complete protection to ambient O3 as the potato yield was higher under ECO2+AO3 compared to ACO2. However, ambient CO2 is not enough to protect the plants under ambient O3 levels. Elevated CO2 also provided protection against elevated O3 by improving the yield. Quality of tubers is modified by both CO2 and O3, which have serious implications on human health at present and in future. Copyright © 2013 Elsevier Inc. All rights reserved.

Ozone Transport Aloft Drives Surface Ozone Maxima Across the Mojave Desert

Science.gov (United States)

VanCuren, R. A.

2014-12-01

A persistent layer of polluted air in the lower free troposphere over the Mojave Desert (California and Nevada) drives spring and summer surface ozone maxima as deep afternoon mixing delivers ozone and ozone precursors to surface measurement sites 200 km or more downwind of the mountains that separate the deserts from the heavily populated coastal areas of California. Pollutants in this elevated layer derive from California source regions (the Los Angeles megacity region and the intensive agricultural region of the San Joaquin Valley), and from long-range transport from Asia. Recognition of this poorly studied persistent layer explains and expands the significance of previously published reports of ozone and other pollutants observed in and over the Mojave Desert, resolves an apparent paradox in the timing of ozone peaks due to transport from the upwind basins, and provides a new perspective on the long-range downwind impacts of megacity pollution plumes.

Ozone, Fine Particulate Matter, and Chronic Lower Respiratory Disease Mortality in the United States.

Science.gov (United States)

Hao, Yongping; Balluz, Lina; Strosnider, Heather; Wen, Xiao Jun; Li, Chaoyang; Qualters, Judith R

2015-08-01

Short-term effects of air pollution exposure on respiratory disease mortality are well established. However, few studies have examined the effects of long-term exposure, and among those that have, results are inconsistent. To evaluate long-term association between ambient ozone, fine particulate matter (PM2.5, particles with an aerodynamic diameter of 2.5 μm or less), and chronic lower respiratory disease (CLRD) mortality in the contiguous United States. We fit Bayesian hierarchical spatial Poisson models, adjusting for five county-level covariates (percentage of adults aged ≥65 years, poverty, lifetime smoking, obesity, and temperature), with random effects at state and county levels to account for spatial heterogeneity and spatial dependence. We derived county-level average daily concentration levels for ambient ozone and PM2.5 for 2001-2008 from the U.S. Environmental Protection Agency's down-scaled estimates and obtained 2007-2008 CLRD deaths from the National Center for Health Statistics. Exposure to ambient ozone was associated with an increased rate of CLRD deaths, with a rate ratio of 1.05 (95% credible interval, 1.01-1.09) per 5-ppb increase in ozone; the association between ambient PM2.5 and CLRD mortality was positive but statistically insignificant (rate ratio, 1.07; 95% credible interval, 0.99-1.14). This study links air pollution exposure data with CLRD mortality for all 3,109 contiguous U.S. counties. Ambient ozone may be associated with an increased rate of death from CLRD in the contiguous United States. Although we adjusted for selected county-level covariates and unobserved influences through Bayesian hierarchical spatial modeling, the possibility of ecologic bias remains.

Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

Science.gov (United States)

Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

2015-12-01

During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen

Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone.

Science.gov (United States)

Pregitzer, Kurt; Loya, Wendy; Kubiske, Mark; Zak, Donald

2006-06-01

The aspen free-air CO2 and O3 enrichment (FACTS II-FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO2) and elevated tropospheric ozone (O3) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the objective of this study was to understand how soil respiration responded to the experimental treatments as these fast-growing stands of pure aspen and birch + aspen approached maximum leaf area. Rates of soil respiration were typically lowest in the elevated O3 treatment. Elevated CO2 significantly stimulated soil respiration (8-26%) compared to the control treatment in both community types over all three growing seasons. In years 6-7 of the experiment, the greatest rates of soil respiration occurred in the interaction treatment (CO2 + O3), and rates of soil respiration were 15-25% greater in this treatment than in the elevated CO2 treatment, depending on year and community type. Two of the treatments, elevated CO2 and elevated CO2 + O3, were fumigated with 13C-depleted CO2, and in these two treatments we used standard isotope mixing models to understand the proportions of new and old C in soil respiration. During the peak of the growing season, C fixed since the initiation of the experiment in 1998 (new C) accounted for 60-80% of total soil respiration. The isotope measurements independently confirmed that more new C was respired from the interaction treatment compared to the elevated CO2 treatment. A period of low soil moisture late in the 2003 growing season resulted in soil respiration with an isotopic signature 4-6 per thousand enriched in 13C compared to sample dates when the percentage soil moisture was higher. In 2004, an extended period of low soil moisture during August and early September, punctuated by a significant rainfall event, resulted in soil

Elevated potassium levels in patients with chronic kidney disease

DEFF Research Database (Denmark)

Thomsen, Reimar W; Nicolaisen, Sia K; Hasvold, Pål

2018-01-01

Background: Data on the true burden of hyperkalemia (HK) in patients with chronic kidney disease (CKD) in a real-world setting are scarce. Methods: The incidence rate of HK [first blood test with an elevated blood potassium level level >5.0 mmol/L] in primary or hospital care was assessed...

Sustained Elevated Adenosine via ADORA2B Promotes Chronic Pain through Neuro-immune Interaction

Directory of Open Access Journals (Sweden)

Xia Hu

2016-06-01

Full Text Available The molecular mechanisms of chronic pain are poorly understood and effective mechanism-based treatments are lacking. Here, we report that mice lacking adenosine deaminase (ADA, an enzyme necessary for the breakdown of adenosine, displayed unexpected chronic mechanical and thermal hypersensitivity due to sustained elevated circulating adenosine. Extending from Ada−/− mice, we further discovered that prolonged elevated adenosine contributed to chronic pain behaviors in two additional independent animal models: sickle cell disease mice, a model of severe pain with limited treatment, and complete Freund’s adjuvant paw-injected mice, a well-accepted inflammatory model of chronic pain. Mechanistically, we revealed that activation of adenosine A2B receptors on myeloid cells caused nociceptor hyperexcitability and promoted chronic pain via soluble IL-6 receptor trans-signaling, and our findings determined that prolonged accumulated circulating adenosine contributes to chronic pain by promoting immune-neuronal interaction and revealed multiple therapeutic targets.

Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

Science.gov (United States)

Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

2014-08-01

Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

Science.gov (United States)

Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

2014-01-01

Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3. Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r2 = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m−2) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (ΔNPP/ΔN) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2. Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after three years of treatments to elevated carbon dioxide and ozone

Science.gov (United States)

Seija Kaakinen; Katri Kostiainen; Fredrik Ek; Pekka Saranpaa; Mark E. Kubiske; Jaak Sober; David F. Karnosky; Elina Vapaavuori

2004-01-01

The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3-year-old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera...

Modeling ozone bioindicator injury with microscale and landscape-scale explanatory variables: A logistic regression approach

Science.gov (United States)

John W. Coulston

2011-01-01

Tropospheric ozone occurs at phytotoxic levels in the United States (Lefohn and Pinkerton 1988). Several plant species, including commercially important timber species, are sensitive to elevated ozone levels. Exposure to elevated ozone can cause growth reduction and foliar injury and make trees more susceptible to secondary stressors such as insects and pathogens (...

New Directions: Ozone-initiated reaction products indoors may be more harmful than ozone itself

Science.gov (United States)

Weschler, Charles J.

2004-10-01

Epidemiological studies have found associations between ozone concentrations measured at outdoor monitoring stations and certain adverse health outcomes. As a recent example, Gent et al. (2003, Journal of the American Medical Association 290, 1859-1867) have observed an association between ozone levels and respiratory symptoms as well as the use of maintenance medication by 271 asthmatic children living in Connecticut and the Springfield area of Massachusetts. In another example, Gilliland et al. (2001, Epidemiology 12, 43-54) detected an association between short-term increases in ozone levels and increased absences among 4th grade students from 12 southern California communities during the period from January to June 1996. Although children may spend a significant amount of time outdoors, especially during periods when ozone levels are elevated, they spend a much larger fraction of their time indoors. I hypothesize that exposure to the products of ozone-initiated indoor chemistry is more directly responsible for the health effects observed in the cited epidemiological studies than is exposure to outdoor ozone itself.

Combined cadmium and elevated ozone affect concentrations of cadmium and antioxidant systems in wheat under fully open-air conditions

International Nuclear Information System (INIS)

Guo, Hongyan; Tian, Ran; Zhu, Jianguo; Zhou, Hui; Pei, Daping; Wang, Xiaorong

2012-01-01

Highlights: ► Combined effect of elevated O 3 and Cd levels on wheat was studied using the free-air concentration enrichment system. ► Elevated O 3 levels result in an increased concentration of Cd in wheat plants grown on Cd-contaminated soils. ► Combined cadmium and elevated O 3 have a significantly synergic effect on oxidative stress in wheat shoots. - Abstract: Pollution of the environment with both ozone (O 3 ) and heavy metals has been steadily increasing. An understanding of their combined effects on plants, especially crops, is limited. Here we studied the effects of elevated O 3 on oxidative stress and bioaccumulation of cadmium (Cd) in wheat under Cd stress using a free-air concentration enrichment (FACE) system. In this field experiment in Jiangdu (Jiangsu Province, China), wheat plants were grown in pots containing soil with various concentrations of cadmium (0, 2, and 10 mg kg −1 Cd was added to the soil) under ambient conditions and under elevated O 3 levels (50% higher than the ambient O 3 ). Present results showed that elevated O 3 led to higher concentrations of Cd in wheat tissues (shoots, husk and grains) with respect to contaminated soil. Combined exposure to Cd and elevated O 3 levels strongly affected the antioxidant isoenzymes POD, APX and CAT and accelerated oxidative stress in wheat leaves. Our results suggest that elevated O 3 levels cause a reduction in food quality and safety.

Forests and ozone: productivity, carbon storage, and feedbacks.

Science.gov (United States)

Wang, Bin; Shugart, Herman H; Shuman, Jacquelyn K; Lerdau, Manuel T

2016-02-22

Tropospheric ozone is a serious air-pollutant, with large impacts on plant function. This study demonstrates that tropospheric ozone, although it damages plant metabolism, does not necessarily reduce ecosystem processes such as productivity or carbon sequestration because of diversity change and compensatory processes at the community scale ameliorate negative impacts at the individual level. This study assesses the impact of ozone on forest composition and ecosystem dynamics with an individual-based gap model that includes basic physiology as well as species-specific metabolic properties. Elevated tropospheric ozone leads to no reduction of forest productivity and carbon stock and to increased isoprene emissions, which result from enhanced dominance by isoprene-emitting species (which tolerate ozone stress better than non-emitters). This study suggests that tropospheric ozone may not diminish forest carbon sequestration capacity. This study also suggests that, because of the often positive relationship between isoprene emission and ozone formation, there is a positive feedback loop between forest communities and ozone, which further aggravates ozone pollution.

The study of international and interstate transport of ozone in Yuma, Arizona

Science.gov (United States)

Li, Y.; Sonenberg, M.; Wood, J. L.; Pearson, C. R.; Colson, H.; Malloy, J. W.; Pace, M.; Mao, F.; Paul, J.; Busby, B. R.; Parkey, B.; Drago, L.; Franquist, T. S.

2017-12-01

In October 2015, EPA reduced the National Ambient Air Quality Standards (NAAQS) for ozone from 75 parts per billion (ppb) to 70 ppb. Meeting the new standard may be extremely challenging for some areas, including rural Yuma County in the State of Arizona. Yuma County faces unique air quality challenges, since it borders the Mexican states of Baja California and Sonora, and the State of California. The present study investigates the contribution of international and interstate transport of ozone and ozone precursors to episodes of elevated ozone concentrations in Yuma. The Arizona Department of Environmental Quality (ADEQ) merged HYSPLIT modeling outputs with two years of hourly ground ozone monitor data to investigate the potential area contributions to ozone concentrations in Yuma County. This analysis found that elevated ozone concentrations in Yuma in 2014 and 2015 frequently coincided with back-trajectories over both California and Mexico, typically favoring Mexico during the spring. In May 2017, ADEQ installed a new ozone monitor in San Luis Rio Colorado, Sonora, Mexico (Latitude: 32.4665, Longitude: -114.7688), which is 29 km south of ozone site in Yuma County. We will present the first simultaneous observations of ozone seasons in Sonora, Mexico, eastern California, and Yuma.

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

International Nuclear Information System (INIS)

Kumari, Sumita; Agrawal, Madhoolika; Tiwari, Supriya

2013-01-01

The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO 2 and O 3 , alone and in combination. As compared to the plants grown in charcoal filtered air (ACO 2 ), growth and yield of the plants increased under elevated CO 2 (ECO 2 ) and decreased under combination of ECO 2 with elevated O 3 (ECO 2 + EO 3 ), ambient O 3 (ACO 2 + AO 3 ) and elevated O 3 (EO 3 ). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO 3. Foliar starch and organic carbon contents increased under ECO 2 and ECO 2 + EO 3 and reduced under EO 3 and ACO 2 + AO 3. Foliar N content declined in all treatments compared to ACO 2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO 2 is not enough to counteract O 3 impact, but elevated CO 2 has potential to counteract the negative effects of future O 3 level. -- Highlights: ► Elevated CO 2 enhanced the growth and yield of palak. ► Ambient and elevated ozone reduced the growth and yield of the test plant. ► Elevated CO 2 reduced negative effects of elevated O 3 by reducing oxidative stress. ► Higher amelioration was recorded at elevated CO 2 + O 3 compared to ambient CO 2 + O 3 . -- Predicted levels of CO 2 have greater ameliorative potential against negative effects of elevated ozone compared to present day CO 2 against ambient ozone

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-06-15

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Physiological responses of Pinus sylvestris to changing carbon dioxide and ozone concentrations

Energy Technology Data Exchange (ETDEWEB)

Holopainen, T [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Palomaeki, V [Joensuu Univ. (Finland). Faculty of Forestry; Helmisaari, H S [Finnish Forest Research Inst., Helsinki (Finland); and others

1997-12-31

The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a negative chamber effect. The elevated ozone significantly increased the chlorotic mottling and overall yellowing of second year needles as well as caused increased density of chloroplast stroma and declined photosynthesis, all these responses being often related to ozone exposures. The ozone related responses appeared at both CO{sub 2} levels indicating no clear protection due to elevated CO{sub 2}. The ozone or carbon dioxide treatments were not able to significantly change nutrient concentrations, insect herbivory or carbon allocation among the secondary compounds of needles. A tendency of increased carbon allocation to fine roots due to ozone but not so clearly to CO{sub 2} was observed

Physiological responses of Pinus sylvestris to changing carbon dioxide and ozone concentrations

Energy Technology Data Exchange (ETDEWEB)

Holopainen, T. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Palomaeki, V. [Joensuu Univ. (Finland). Faculty of Forestry; Helmisaari, H.S. [Finnish Forest Research Inst., Helsinki (Finland)] [and others

1996-12-31

The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a negative chamber effect. The elevated ozone significantly increased the chlorotic mottling and overall yellowing of second year needles as well as caused increased density of chloroplast stroma and declined photosynthesis, all these responses being often related to ozone exposures. The ozone related responses appeared at both CO{sub 2} levels indicating no clear protection due to elevated CO{sub 2}. The ozone or carbon dioxide treatments were not able to significantly change nutrient concentrations, insect herbivory or carbon allocation among the secondary compounds of needles. A tendency of increased carbon allocation to fine roots due to ozone but not so clearly to CO{sub 2} was observed

Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches.

Science.gov (United States)

Manninen, S; Huttunen, S; Vanhatalo, M; Pakonen, T; Hämäläinen, A

2009-05-01

We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O(3)) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O(3), i.e. O(3) levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O(3) and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.

Effects of Elevated Ozone on Polka Dot Plant (Hypoestes phyllostachya) with Variegated Leaves.

Science.gov (United States)

Sui, J X; Wen, M X; Jia, L L; Chen, Y J; Li, C H; Zhang, L

2017-10-01

In this study, impacts of O 3 on four cultivars ('Rose', 'Pink', 'Blush' and 'White') of the polka dot plant with variegated leaves were investigated for the first time. Ozone fumigation [(120 ± 20 ppb) for 14 days (8 h day -1 , from 8:30 to 16:30)] resulted in visible foliar injuries, decreased contents of pigments (chlorophyll a and b, and carotenoid), the inhibition of photosynthesis, the increase of quantum yield of non-regulated heat dissipation and fluorescence emission (Y(NO)), and the damage of cell membrane. Elevated O 3 increased the content of anthocyanin (Ant). 'White' showed the highest, and 'Rose' the lowest amount of injured leaf area, indicating that the former was the most sensitive, and the latter the most tolerant to O 3 stress. After O 3 exposure, the highest Ant content was found in 'Rose', followed by 'Pink', 'Blush', and 'White'. Levels of Ant were likely responsible for the different sensitivities to O 3 due to their roles in photoprotection.

Coincident Observations of Surface Ozone and NMVOCs over Abu Dhabi

Science.gov (United States)

Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Tarasick, David; Davies, Jonathan; Riemer, Daniel; Apel, Eric

2016-07-01

The vertical profiles of ozone are measured coincidently with non-methane volatile organic compounds (NMVOCs) at the meteorological site located at the Abu Dhabi international airport (latitude 24.45N; longitude 54.22E) during the years 2012 - 2014. Some of the profiles show elevated surface ozone >95 ppbv during the winter months (December, January and February). The ground-level NMVOCs obtained from the gas chromatography-flame ionization detection/mass spectrometry system also show elevated values of acetylene, ethane, propane, butane, pentane, benzene, and toluene. NMVOCs and ozone abundances in other seasons are much lower than the values in winter season. NMVOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption, and serve as precursor of ozone. Transport sources contribute a substantial portion of the NMVOC burden to the urban atmosphere in developed regions. Abu Dhabi is located at the edge of the Arabian Gulf and is highly affected by emissions from petrochemical industries in the neighboring Gulf region. The preliminary results indicate that wintertime enhancement in ozone is associated with large values of NMVOCs at Abu Dhabi. The domestic production of surface ozone is estimated from the combination of oxygen recombination and NMVOCs and compared with the data. It is estimated that about 40-50% of ozone in Abu Dhabi is transported from the neighbouring petrochemical industries. We will present ozone sounding and NMVOCs data and our model estimates of surface ozone, including a discussion on the high levels of the tropospheric ozone responsible for contaminating the air quality in the UAE. This work is supported by National Research Foundation, UAE.

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

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-09-01

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

Effects of elevated ozone concentration on CH4 and N2O emission from paddy soil under fully open-air field conditions.

Science.gov (United States)

Tang, Haoye; Liu, Gang; Zhu, Jianguo; Kobayashi, Kazuhiko

2015-04-01

We investigated the effects of elevated ozone concentration (E-O3) on CH4 and N2O emission from paddies with two rice cultivars: an inbred Indica cultivar Yangdao 6 (YD6) and a hybrid one II-you 084 (IIY084), under fully open-air field conditions in China. A mean 26.7% enhancement of ozone concentration above the ambient level (A-O3) significantly reduced CH4 emission at tillering and flowering stages leading to a reduction of seasonal integral CH4 emission by 29.6% on average across the two cultivars. The reduced CH4 emission is associated with O3-induced reduction in the whole-plant biomass (-13.2%), root biomass (-34.7%), and maximum tiller number (-10.3%), all of which curbed the carbon supply for belowground CH4 production and its release from submerged soil to atmosphere. Although no significant difference was detected between the cultivars in the CH4 emission response to E-O3, a larger decrease in CH4 emission with IIY084 (-33.2%) than that with YD6 (-7.0%) was observed at tillering stage, which may be due to the larger reduction in tiller number in IIY084 by E-O3. Additionally, E-O3 reduced seasonal mean NOx flux by 5.7% and 11.8% with IIY084 and YD6, respectively, but the effects were not significant statistically. We found that the relative response of CH4 emission to E-O3 was not significantly different from those reported in open-top chamber experiments. This study has thus confirmed that increasing ozone concentration would mitigate the global warming potential of CH4 and suggested consideration of the feedback mechanism between ozone and its precursor emission into the projection of future ozone effects on terrestrial ecosystem. © 2014 John Wiley & Sons Ltd.

Tropospheric Enhancement of Ozone over the UAE

Science.gov (United States)

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

2015-04-01

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

Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models

Directory of Open Access Journals (Sweden)

V. Eyring

2010-10-01

Full Text Available Projections of stratospheric ozone from a suite of chemistry-climate models (CCMs have been analyzed. In addition to a reference simulation where anthropogenic halogenated ozone depleting substances (ODSs and greenhouse gases (GHGs vary with time, sensitivity simulations with either ODS or GHG concentrations fixed at 1960 levels were performed to disaggregate the drivers of projected ozone changes. These simulations were also used to assess the two distinct milestones of ozone returning to historical values (ozone return dates and ozone no longer being influenced by ODSs (full ozone recovery. The date of ozone returning to historical values does not indicate complete recovery from ODSs in most cases, because GHG-induced changes accelerate or decelerate ozone changes in many regions. In the upper stratosphere where CO₂-induced stratospheric cooling increases ozone, full ozone recovery is projected to not likely have occurred by 2100 even though ozone returns to its 1980 or even 1960 levels well before (~2025 and 2040, respectively. In contrast, in the tropical lower stratosphere ozone decreases continuously from 1960 to 2100 due to projected increases in tropical upwelling, while by around 2040 it is already very likely that full recovery from the effects of ODSs has occurred, although ODS concentrations are still elevated by this date. In the midlatitude lower stratosphere the evolution differs from that in the tropics, and rather than a steady decrease in ozone, first a decrease in ozone is simulated from 1960 to 2000, which is then followed by a steady increase through the 21st century. Ozone in the midlatitude lower stratosphere returns to 1980 levels by ~2045 in the Northern Hemisphere (NH and by ~2055 in the Southern Hemisphere (SH, and full ozone recovery is likely reached by 2100 in both hemispheres. Overall, in all regions except the tropical lower stratosphere, full ozone recovery from ODSs occurs significantly later than the

Extremely elevated alpha-fetoprotein due to acute exacerbation of chronic hepatitis B without malignancy: a case report.

Science.gov (United States)

Yoon, Young-Min; Kang, Da-Yeong; Kim, Da-Young; Seo, Jun-Won; Lim, Hyun-Jong; Lee, Hee-Jeong; Park, Sang-Gon

2016-06-01

Alpha-fetoprotein is produced by a variety of tumors such as hepatocellular carcinoma, hepatoblastoma, and germ cell tumors of the ovary and testes. However, we present a case of significantly elevated serum alpha-fetoprotein without evidence of malignant disease in a patient who is a carrier of chronic hepatitis B. A 60-year-old Korean man presented with markedly increased alpha-fetoprotein (2350 ng/mL; normal 7 × 105 IU/mL). Our patient was diagnosed with acute exacerbation of chronic hepatitis B, and we presumed that this condition might be related to extremely elevated alpha-fetoprotein. When our patient was treated with entecavir, the serum alpha-fetoprotein level immediately decreased, in parallel with the hepatitis B virus deoxyribonucleic acid copy number. We report a rare case of extremely elevated alpha-fetoprotein due to acute exacerbation of chronic hepatitis B without any malignancy, and a decrease in this tumor marker simultaneous with a decrease in hepatitis B virus deoxyribonucleic acid copy number on entecavir treatment. This case report is important due to the rarity of the case; furthermore, it provides details of a diagnostic process for a variety of benign diseases and malignant tumors that should be considered in patients with elevated alpha-fetoprotein. Thus, we present a case report, along with a review, that will be helpful for diagnosis and treatment of patients with elevated alpha-fetoprotein.

Nicotiana tabacum as model for ozone - plant surface reactions

Science.gov (United States)

Jud, Werner; Fischer, Lukas; Wohlfahrt, Georg; Tissier, Alain; Canaval, Eva; Hansel, Armin

2015-04-01

Elevated tropospheric ozone concentrations are considered a toxic threat to plants, responsible for global crop losses with associated economic costs of several billion dollars per year. The ensuing injuries have been related to the uptake of ozone through the stomatal pores and oxidative effects damaging the internal leaf tissue. A striking question of current research is the environment and plant specific partitioning of ozone loss between gas phase, stomatal or plant surface sink terms. Here we show results from ozone fumigation experiments using various Nicotiana Tabacum varieties, whose surfaces are covered with different amounts of unsaturated diterpenoids exuded by their glandular trichomes. Exposure to elevated ozone levels (50 to 150 ppbv) for 5 to 15 hours in an exceptionally clean cuvette system did neither result in a reduction of photosynthesis nor caused any visible leaf damage. Both these ozone induced stress effects have been observed previously in ozone fumigation experiments with the ozone sensitive tobacco line Bel-W3. In our case ozone fumigation was accompanied by a continuous release of oxygenated volatile organic compounds, which could be clearly associated to their condensed phase precursors for the first time. Gas phase reactions of ozone were avoided by choosing a high enough gas exchange rate of the plant cuvette system. In the case of the Ambalema variety, that is known to exude only the diterpenoid cis-abienol, ozone fumigation experiments yield the volatiles formaldehyde and methyl vinyl ketone (MVK). The latter could be unequivocally separated from isomeric methacrolein (MACR) by the aid of a Selective Reagent Ion Time-of-Flight Mass Spectrometer (SRI-ToF-MS), which was switched every six minutes from H3O+ to NO+ primary ion mode and vice versa. Consistent with the picture of an ozone protection mechanism caused by reactive diterpenoids at the leaf surface are the results from dark-light experiments. The ozone loss obtained from the

Phenogenetic response of silver birch populations and half-sib families to elevated ozone and ultraviolet-B radiation at juvenile age

International Nuclear Information System (INIS)

Pliura, Alfas; Baliuckiene, Asta; Baliuckas, Virgilijus

2008-01-01

Phenogenetic response of silver birch populations and half-sib families to separate and combined elevated ozone (O 3 ) concentrations and ultraviolet-B (UV-B) radiation dozes was studied at juvenile age in the climatic chambers. Significant population and family effects were found for seedling height, lamina width, and leaf damage. The exposure to UV-B radiation decreased genetic variation at the stage of seed germination. Complex exposure to UV-B and O 3 caused an increase of genetic variation at the stage of intensive seedling growth: seedling height genetic variation in separate treatments increased from 23.7-38.6 to 33.7-65.7%, the increase for lamina width was from 10.2-13.9 to 13.6-31.8%. Different populations and families demonstrated differing response to elevated complex UV-B and O 3 exposure. Changes of genetic intra-population variation were population-specific. Such changes in genetic variation under the impact of stressors can alter adaptation, stability, and competitive ability of regenerating populations in a hardly predictive way. - Exposure to elevated UV-B and O 3 alters genetic variation of traits in progenies of silver birch populations

Phenogenetic response of silver birch populations and half-sib families to elevated ozone and ultraviolet-B radiation at juvenile age

Energy Technology Data Exchange (ETDEWEB)

Pliura, Alfas [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Lithuanian University of Agriculture, Studentu 13, LT-53361 Akademija, Kaunas District (Lithuania)], E-mail: genetsk@mi.lt; Baliuckiene, Asta [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Baliuckas, Virgilijus [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Lithuanian University of Agriculture, Studentu 13, LT-53361 Akademija, Kaunas District (Lithuania)

2008-11-15

Phenogenetic response of silver birch populations and half-sib families to separate and combined elevated ozone (O{sub 3}) concentrations and ultraviolet-B (UV-B) radiation dozes was studied at juvenile age in the climatic chambers. Significant population and family effects were found for seedling height, lamina width, and leaf damage. The exposure to UV-B radiation decreased genetic variation at the stage of seed germination. Complex exposure to UV-B and O{sub 3} caused an increase of genetic variation at the stage of intensive seedling growth: seedling height genetic variation in separate treatments increased from 23.7-38.6 to 33.7-65.7%, the increase for lamina width was from 10.2-13.9 to 13.6-31.8%. Different populations and families demonstrated differing response to elevated complex UV-B and O{sub 3} exposure. Changes of genetic intra-population variation were population-specific. Such changes in genetic variation under the impact of stressors can alter adaptation, stability, and competitive ability of regenerating populations in a hardly predictive way. - Exposure to elevated UV-B and O{sub 3} alters genetic variation of traits in progenies of silver birch populations.

Production and Transport of Ozone From Boreal Forest Fires

Science.gov (United States)

Tarasick, David; Liu, Jane; Osman, Mohammed; Sioris, Christopher; Liu, Xiong; Najafabadi, Omid; Parrington, Mark; Palmer, Paul; Strawbridge, Kevin; Duck, Thomas

2013-04-01

In the summer of 2010, the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) mission was planned by several universities and government agencies in the United Kingdom, Canada, and USA. Nearly 100 ozone soundings were made at 13 stations through the BORTAS Intensive Sounding Network, although aircraft measurements were unfortunately cancelled due to the volcanic eruption in Iceland. 2010 was actually an exceptional year for Canadian boreal fires. MODIS (Moderate Resolution Imaging Spectroradiometer) fire count data shows large fire events in Saskatchewan on several days in July. High amounts of NO2 close to the large fires are observed from OMI satellite data, indicating that not all NO2 is converted to PAN. Also associated with the fires, large amounts of CO, another precursor of ozone, are observed in MOPITT (Measurements Of Pollution In The Troposphere), AIRS and TES (Tropospheric Emission Spectrometer) satellite data in the middle to upper troposphere. These chemical conditions combined with sunny weather all favour ozone production. Following days with large fire activity, layers of elevated ozone mixing ratio (over 100 ppbv) are observed downwind at several sites. Back-trajectories suggest the elevated ozone in the profile is traceable to the fires in Saskatchewan. Lidar profiles also detect layers of aerosol at the same heights. However, the layers of high ozone are also associated with low humidity, which is not expected from a combustion source, and suggests the possibility of entrainment of stratospheric air.

Analysing the causes of chronic cough: relation to diesel exhaust, ozone, nitrogen oxides, sulphur oxides and other environmental factors

Directory of Open Access Journals (Sweden)

Wagner Ulrich

2006-05-01

Full Text Available Abstract Air pollution remains a leading cause of many respiratory diseases including chronic cough. Although episodes of incidental, dramatic air pollution are relatively rare, current levels of exposure of pollutants in industrialized and developing countries such as total articles, diesel exhaust particles and common cigarette smoke may be responsible for the development of chronic cough both in children and adults. The present study analyses the effects of common environmental factors as potential causes of chronic cough. Different PubMed-based researches were performed that related the term cough to various environmental factors. There is some evidence that chronic inhalation of diesel can lead to the development of cough. For long-term exposure to nitrogen dioxide (NO2, children were found to exhibit increased incidences of chronic cough and decreased lung function parameters. Although a number of studies did not show that outdoor pollution directly causes the development of asthma, they have demonstrated that high levels pollutants and their interaction with sunlight produce ozone (O3 and that repeated exposure to it can lead to chronic cough. In summary, next to the well-known air pollutants which also include particulate matter and sulphur dioxide, a number of other indoor and outdoor pollutants have been demonstrated to cause chronic cough and therefore, environmental factors have to be taken into account as potential initiators of both adult and pediatric chronic cough.

OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

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Krzysztof Skotak

2010-03-01

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

Transport aloft drives peak ozone in the Mojave Desert

Science.gov (United States)

VanCuren, Richard

2015-05-01

Transport of anthropogenic pollution eastward out of the Los Angeles megacity region in California has been periodically observed to reach the Colorado River and the Colorado Plateau region beyond. In the 1980s, anthropogenic halocarbon tracers measured in and near the Las Angeles urban area and at a mountain-top site near the Colorado River, 400 km downwind, were shown to have a correlated seven-day cycle explainable by transport from the urban area with a time lag of 1-2 days. Recent short term springtime intensive studies using aircraft observations and regional modeling of long range transport of ozone from the Southern California megacity region showed frequent and persistent ozone impacts at surface sites across the Colorado Plateau and Southern Rocky Mountain region, at distances up to 1500 km, also with time lags of 1-2 days. However, the timing of ozone peaks at low altitude monitoring sites within the Mojave Desert, at distances from 100 to 400 km from the South Coast and San Joaquin Valley ozone source regions, does not show the expected time-lag behavior seen in the larger transport studies. This discrepancy is explained by recognizing ozone transport across the Mojave Desert to occur in a persistent layer of polluted air in the lower free troposphere with a base level at approximately 1 km MSL. This layer impacts elevated downwind sites directly, but only influences low altitude surface ozone maxima through deep afternoon mixing. Pollutants in this elevated layer derive from California source regions (the Los Angeles megacity region and the intensive agricultural region of the San Joaquin Valley), from long-range transport from Asia, and stratospheric down-mixing. Recognition of the role of afternoon mixing during spring and summer over the Mojave explains and expands the significance of previously published reports of ozone and other pollutants observed in and over the Mojave Desert, and resolves an apparent paradox in the timing of ozone peaks due to

Association of Overweight and Elevation with Chronic Knee and Low Back Pain: A Cross-Sectional Study

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Tsuyoshi Hamano

2014-04-01

Full Text Available It is known that overweight is associated with chronic knee pain (CKP and chronic low back pain (CLBP. Several risk factors for these conditions have been postulated, including age, sex, overweight, occupation, and socioeconomic factors. In addition, physical environment has been studied as a potential risk factor in recent years. However, the associations of overweight and physical environment with CKP and CLBP remains unclear. The aim of this study conducted in a rural mountainous region was to examine whether overweight individuals living at higher elevations have an increased probability of experiencing CKP and CLBP. In 2009, we conducted a mail survey with a random sample aged between 40 to 79 years. Questionnaires were sent to 6,000 individuals and a total of 4,559 individuals responded to this survey. After excluding the respondents with missing data, we conducted a logistic regression analysis of the data for 3,109 individuals. There was statistically significantly higher adjusted odds ratio (aOR of CKP for those who were overweight living at low elevation (aOR = 1.90, 95% CI = 1.21–2.98, moderate elevation (aOR = 1.73, 95% CI = 1.05–2.87, and high elevation (aOR = 2.13, 95% CI = 1.31–3.46 than those who were not overweight living at low elevation. However, similar patterns were not observed for CLBP. Our results show that specific overweight–elevation associations were observed for CKP in a rural mountainous region.

DNA damage in Populus tremuloides clones exposed to elevated O3

International Nuclear Information System (INIS)

Tai, Helen H.; Percy, Kevin E.; Karnosky, David F.

2010-01-01

The effects of elevated concentrations of atmospheric tropospheric ozone (O 3 ) on DNA damage in five trembling aspen (Populus tremuloides Michx.) clones growing in a free-air enrichment experiment in the presence and absence of elevated concentrations of carbon dioxide (CO 2 ) were examined. Growing season mean hourly O 3 concentrations were 36.3 and 47.3 ppb for ambient and elevated O 3 plots, respectively. The 4th highest daily maximum 8-h ambient and elevated O 3 concentrations were 79 and 89 ppb, respectively. Elevated CO 2 averaged 524 ppm (+150 ppm) over the growing season. Exposure to O 3 and CO 2 in combination with O 3 increased DNA damage levels above background as measured by the comet assay. Ozone-tolerant clones 271 and 8L showed the highest levels of DNA damage under elevated O 3 compared with ambient air; whereas less tolerant clone 216 and sensitive clones 42E and 259 had comparably lower levels of DNA damage with no significant differences between elevated O 3 and ambient air. Clone 8L was demonstrated to have the highest level of excision DNA repair. In addition, clone 271 had the highest level of oxidative damage as measured by lipid peroxidation. The results suggest that variation in cellular responses to DNA damage between aspen clones may contribute to O 3 tolerance or sensitivity. - Ozone tolerant clones and sensitive Populus tremuloides clones show differences in DNA damage and repair.

Legacy effects of elevated ozone on soil biota and plant growth

NARCIS (Netherlands)

Li, Q.; Yang, Y.; Bao, X.; Liu, F.; Liang, W.; Zhu, J.; Bezemer, T.M.; Putten, van der W.H.

2015-01-01

Many studies have examined how human-induced atmospheric changes will influence ecosystems. The long-term consequences of human induced climate changes on terrestrial ecosystems may be determined to a large extend by how the belowground compartment will respond to these changes. In a free-air ozone

Long-term effects of ozone on CO2 exchange in peatland microcosms

DEFF Research Database (Denmark)

Haapala, JK; Mörsky, SK; Rinnan, Riikka

2011-01-01

Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate of the mic......Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate...... exchange of the peatland microcosms....

Urban and Rural Ozone Pollution Over Lusaka (Zambia, 15.5S, 25E) During SAFARI-2000 (September 2000)

Science.gov (United States)

Thompson, Anne M.; Herman, J. R.; Witte, J. C.; Phahlane, A.; Coetzee, G. J. R.; Mukula, C.; Hudson, R. D.; Frolov, A. D.; Bhartia, P. K. (Technical Monitor)

2001-01-01

In early September, throughout south central Africa, seasonal clearing of dry vegetation and the production of charcoal for cooking leads to intense smoke haze and ozone formation. Ozone soundings made over Lusaka during a six-day period in early September 2000 recorded layers of high ozone (greater than 125 ppbv at 5 km) during two stagnant periods, interspersed by a frontal passage that reduced boundary layer ozone by 30 percent. Smoke aerosol column variations aloft and total ozone were monitored by a sun photometer. During the 6-day measurement period, surface ozone concentrations ranged from 50-95 ppbv and integrated tropospheric ozone from the soundings was 39- 54 Dobson Units (note 1.3 km elevation at the launch site). High ozone concentrations above the mixed and inversion layers were advected from rural burning regions in western Zambia where SAFARI aircraft and ground-based instruments observed intense biomass fires and elevated aerosol and trace gas amounts. TOMS tropospheric ozone and smoke aerosols products show the distribution of biomass burning and associated pollution throughout southern Africa in September 2000. Animations of satellite images and trajectories confirm pollutant recirculation over south central African fires, exit of ozone from Mozambique and Tanzania to the Indian Ocean and the characteristic buildup of tropospheric ozone over the Atlantic from western African outflow.

Studies on the Biological Effects of Ozone: 10. Release of Factors from Ozonated Human Platelets

Directory of Open Access Journals (Sweden)

G. Valacchi

1999-01-01

Full Text Available In a previous work we have shown that heparin, in the presence of ozone (O3, promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF, transforming growth factor β1 (TGF-β1 and interleukin-8(IL-8 are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limbischemia treated with O3 autohaemoteraphy (O3-AHT.

Indoor secondary pollutants from cleaning product and air freshener use in the presence of ozone

DEFF Research Database (Denmark)

Singer, B.C.; Coleman, B.K.; Destaillats, H.

2006-01-01

introduction. In the absence of reactive chemicals, the chamber ozone level was approximately 60 ppb. Ozone was substantially consumed following cleaning product use, mainly by homogeneous reaction. For the AFR, ozone consumption was weaker and heterogeneous reaction with sorbed AFR-constituent VOCs...... than 100 mu g m(-3)) in some experiments. Ozone consumption and elevated hydroxyl radical concentrations persisted for 10-12 h following brief cleaning events, indicating that secondary pollutant production can persist for extended periods. (c) 2006 Elsevier Ltd. All rights reserved....

Ozone carcinogenesis in vitro and its co-carcinogenesis with radiation

International Nuclear Information System (INIS)

Borek, C.

1988-01-01

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

Lusaka, Zambia during SAFARI-2000: A Collection Point for Ozone Pollution

Science.gov (United States)

Thompson, Anne M.; Witte, Jacquelyn C.; Freiman, M. Tal; Phahlane, N. Agnes; Coetzee, G. J. R.; Bhartia, P. K. (Technical Monitor)

2002-01-01

In August and September, throughout south central Africa, seasonal clearing of dry vegetation and other fire-related activities lead to intense smoke haze and ozone formation. The first ozone soundings in the heart of the southern African burning region were taken at Lusaka, Zambia (155 deg S, 28 deg E) in early September 2000. Over 90 ppbv ozone was recorded at the surface (1.3 km elevation) and column tropospheric ozone was greater than 50 DU during a stagnant period. These values are much higher than concurrent measurements over Nairobi (1 deg S, 38 deg E) and Irene (25 deg S, 28 deg E, near Pretoria). The heaviest ozone pollution layer (800-500 hPa) over Lusaka is due to recirculated trans-boundary ozone. Starting out over Zambia, Angola, and Namibia, ozone heads east to the Indian Ocean, before turning back over Mozambique and Zimbabwe, heading toward Lusaka. Thus, Lusaka is a collection point for pollution, consistent with a picture of absolutely stable layers recirculating in a gyre over southern Africa.

The Transition of Atmospheric Infrared Sounder Total Ozone Products to Operations

Science.gov (United States)

Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

2014-01-01

The National Aeronautics and Space Administration Short-term Prediction Research and Transition Center (NASA SPoRT) has transitioned a total column ozone product from the Atmospheric Infrared Sounder (AIRS) retrievals to the Weather Prediction Center and Ocean Prediction Center. The total column ozone product is used to diagnose regions of warm, dry, ozone-rich, stratospheric air capable of descending to the surface to create high-impact non-convective winds. Over the past year, forecasters have analyzed the Red, Green, Blue (RGB) Air Mass imagery in conjunction with the AIRS total column ozone to aid high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. During the summer of 2013, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air. This paper describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the RGB Air Mass product to access the utility and transition of the products.

Impacts of elevated ozone on growth and photosynthesis of Metasequoia glyptostroboides Hu et Cheng.

Science.gov (United States)

Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Niu, Junfeng

2014-09-01

One-year-old Metasequoia glyptostroboides seedlings were exposed to non-filtered ambient air (NF) and elevated ozone (E-O3, NF+60 ppb) in open-top chambers for two years. E-O3 accelerated leaf senescence, as indicated by significant decreases in photosynthetic pigment contents with the elongation of O3 exposure. E-O3 significantly affected gas exchange and carboxylation, inducing reductions in light-saturated photosynthesis (Asat), the maximum activity of Rubisco (Vc,max) and the maximum electron transport rate (Jmax). Chl a/b, Vc,max/Jmax and stomatal limitation (l) were not affected. Stomatal conductance (gs) was significantly decreased by E-O3 in the first year, but remained unchanged in the second year. It can be inferred that the decrease in Asat by E-O3 was mainly attributed to the changes in non-stomatal factors. After two years' exposure, E-O3 caused significant decreases in canopy photosynthesis and leaf mass per area, and a significant increase in the number of branches, but induced slight, not significant decreases in growth and biomass. Therefore, it can be concluded that the carbon accumulation of the species M. glyptostroboides could be negatively affected after long-term exposure to high O3 concentration. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Association of TSH Elevation with All-Cause Mortality in Elderly Patients with Chronic Kidney Disease.

Directory of Open Access Journals (Sweden)

Mei-Hsing Chuang

Full Text Available Chronic kidney disease (CKD is a widespread condition in the global population and is more common in the elderly. Thyroid-stimulating hormone (TSH level increases with aging, and hypothyroidism is highly prevalent in CKD patients. However, the relationship between low thyroid function and mortality in CKD patients is unclear. Therefore, we conducted a retrospective cohort study to examine the relationship between TSH elevation and all-cause mortality in elderly patients with CKD. This retrospective cohort study included individuals ≥65 years old with CKD (n = 23,786 in Taipei City. Health examination data from 2005 to 2010 were provided by the Taipei Databank for Public Health Analysis. Subjects were categorized according to thyroid-stimulating hormone (TSH level as follows: low normal (0.34elevated I (5.2≤TSH<10 mIU/L, and elevated II (TSH≥10 mIU/L. Risk of mortality was evaluated using a Cox proportional hazard regression model adjusted for sex, age, hypertension, diabetes mellitus, CKD stage, serum albumin, high-density lipoprotein cholesterol, uric acid, hemoglobin, body mass index, glutamic-pyruvic transaminase, smoking, alcohol consumption, and history of cardiovascular disease (coronary artery disease, congestive heart failure, cerebral vascular disease, history of cancer, and history of chronic obstructive pulmonary disease. Our results showed that compared to the reference group (middle normal TSH, the risk of all-cause mortality was increased in the elevated I group (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.02-1.45 and elevated II group (HR, 1.30; 95% CI, 1.00-1.69. We found a significant association between TSH elevation and all-cause mortality in this cohort of elderly persons with CKD. However, determining the benefit of treatment for moderately elevated TSH level (5.2-10 mIU/L in elderly patients with CKD will require a

Clinical investigation of CT-guided ozone-blowing and fumigation ...

African Journals Online (AJOL)

Clinical investigation of CT-guided ozone-blowing and fumigation therapy for the chronic ... African Journal of Biotechnology ... In control group, seven patients were completely cured in 45 days after being treated by traditional surgery.

Isoprene biosynthesis in hybrid poplar impacts ozone tolerance

Science.gov (United States)

Behnke, K.; Kleist, E.; Uerlings, R.; Wildt, J.; Rennenberg, H.; Schnitzler, J. P.

2009-04-01

Isoprene is the most abundant volatile compound emitted by vegetation. It influences air chemistry and is thought to take part in plant defense reactions against abiotic stress such as high temperature or ozone. However, whether or not isoprene emission interacts with ozone tolerance of plants is still in discussion. We exploited transgenic non-isoprene emitting Grey poplar (Populus x canescens) in a biochemical and physiological model study to investigate the effect of acute ozone stress on the elicitation of defense-related emissions of plant volatiles, photosynthesis and the antioxidative system. We recorded that non-isoprene emitting poplars are more resistant to ozone as indicated by less damaged leaf area and higher assimilation rates compared to ozone-exposed wild type plants. The integral of green leaf volatile (GLV) emissions was different between the two poplar phenotypes and a reliable early marker for subsequent leaf damage. For other stress-induced volatiles like mono-, homo-, and sesquiterpenes, and methyl salicylate similar time profiles, pattern and emission intensities were observed in both transgenic and wild type plants. However, un-stressed non-isoprene emitting poplars are characterized by elevated levels of ascorbate and α-tocopherol as well as a more effective de-epoxidation ratio of xanthophylls than in wild type plants. Since ozone quenching properties of ascorbate are much higher than those of isoprene and furthermore α-tocopherol also is an essential antioxidant, non-isoprene emitting poplars might benefit from changes within the antioxidative system by providing them with enhanced ozone tolerance.

Ozone autohaemotherapy protects against ketamine hydrochloride ...

African Journals Online (AJOL)

Ozone is currently under scrutiny because of various claims of beneficial effect in disease. In order to shed some light on this we assessed the acute and chronic effect of O3 autohaemotherapy (AHT) on liver and muscle damage in baboons. Five percent of the total blood volume of a baboon was treated with O2 and O3.

Transportable lidar for the measurement of ozone concentration and flux profiles in the lower troposphere

International Nuclear Information System (INIS)

Zhao, Yanzeng; Howell, J.N.; Hardesty, R.M.

1992-01-01

In many areas of the United States, as well as in other industrial areas (such as Europe), elevated and potentially harmful levels of ozone are being measured during summer. Most of this ozone is photochemically produced. The relatively long lifetime of ozone allows industrially produced ozone to be transported on a hemispheric scale. Since the trends of tropospheric ozone are very likely dependent on the source strengths and distributions of the pollutants and the chemical/ transport process involved, a predictive understanding of tropospheric ozone climatology requires a focus on the chemical and transport processes that link regional emissions to hemispheric ozone trends and distributions. Of critical importance to these studies is a satisfactory data base of tropospheric ozone distribution from which global and regional tropospheric ozone climatology can be derived, and the processes controlling tropospheric ozone can be better understood. A transportable lidar for measuring ozone concentration and flux profiles in the lower troposphere is needed. One such system is being developed at the National Oceanic and Atmospheric Administration/Earth Resources Laboratory (NOAA/ERL) Wave Propagation Laboratory (WPL)

Effect of ozonation on microbial fish pathogens, ammonia, nitrate, nitrite, and bod in simulated reuse hatchery water

Energy Technology Data Exchange (ETDEWEB)

Colberg, P.J.; Lingg, A.J.

1978-10-01

The effectiveness of ozone for eliminating fish pathogens and reducing nitrite, ammonia, and BOD associated with reuse hatchery systems was evaluated. Comparative survival rates of four bacterial fish pathogens and a bacterium-protozoan population during batch and continuous flow ozonation indicated a specific microbial ozone demand during batch treatment and 99% mortality of pathogens during continuous flow treatment. Oxidation of carbon and nitrite by ozone was rapid at low ozone concentrations; carbon and ammonia oxidation rates were pH dependent. The oxidation capacity of ozone in water was greatest at elevated pH even though lower ozone concentrations were used. Ozone treatment appears to be successful for disinfecting hatchery makeup water for recycling. However, the economics of such treatment are yet to be determined. (10 graphs, 28 references, 1 table)

Antiretroviral Drugs and Risk of Chronic Alanine Aminotransferase Elevation in Human Immunodeficiency Virus (HIV)-Monoinfected Persons

DEFF Research Database (Denmark)

Kovari, Helen; Sabin, Caroline A; Ledergerber, Bruno

2016-01-01

Background.  Although human immunodeficiency virus (HIV)-positive persons on antiretroviral therapy (ART) frequently have chronic liver enzyme elevation (cLEE), the underlying cause is often unclear. Methods.  Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) Study participants without ...

Ozone therapy in postgraduate theses in Egypt: systematic review.

Science.gov (United States)

AlBedah, Abdullah M N; Khalil, Mohamed K M; Elolemy, Ahmed T; Alrasheid, Mohamed H S; Al Mudaiheem, Abdullah; Elolemy, Tawfik M B

2013-08-01

Systematic reviews of the studies published in the major medical data bases have not shown solid support for the use of ozone therapy. Unpublished or grey literature, including postgraduate theses, may solve this controversy. To review the postgraduate theses published in Egypt in order to assess the clinical safety and effectiveness of ozone therapy in specific medical conditions. The databases of the Egyptian Universities' Library Consortium and the databases of each university were searched for postgraduate theses that evaluated ozone therapy as an intervention for any disease or condition in any age group, compared with any or no other intervention and published before September 2010. A total of 28 quasi trials were included. The theses did not report any safety issues in terms of ozone therapy. With respect to its effectiveness, the studies suggested some benefits of ozone in the treatment of dental infection and recovery, musculoskeletal disorders, diabetes mellitus, chronic diseases, and obstetrics and gynaecology. However, the number of studies included was small and they were of limited quality. There is insufficient evidence to recommend the use of ozone in the treatment of dental infections, in facilitating faster dental recovery after extraction or implantation, in diabetes mellitus, musculoskeletal disorders, or obstetrics and gynaecology.

Meteorological and chemical impacts on ozone formation: A case study in Hangzhou, China

Science.gov (United States)

Li, Kangwei; Chen, Linghong; Ying, Fang; White, Stephen J.; Jang, Carey; Wu, Xuecheng; Gao, Xiang; Hong, Shengmao; Shen, Jiandong; Azzi, Merched; Cen, Kefa

2017-11-01

Regional ozone pollution has become one of the most challenging problems in China, especially in the more economically developed and densely populated regions like Hangzhou. In this study, measurements of O3, CO, NOx and non-methane hydrocarbons (NMHCs), together with meteorological data, were obtained for the period July 1, 2013-August 15, 2013 at three sites in Hangzhou. These sites included an urban site (Zhaohui ;ZH;), a suburban site (Xiasha ;XS;) and a rural site (Qiandaohu ;QDH;). During the observation period, both ZH and XS had a higher ozone level than QDH, with exceeding rates of 41.3% and 47.8%, respectively. Elevated O3 levels in QDH were found at night, which could be explained by less prominent NO titration effect in rural area. Detailed statistical analysis of meteorological and chemical impacts on ozone formation was carried out for ZH, and higher ozone concentration was observed when the wind direction was from the east. This is possibly due to emissions of VOCs from XS, a typical chemical industrial park located in 30 km upwind area of ZH. A comprehensive comparison between three ozone episode periods and one non-episode period were made in ZH. It was concluded that elevated concentrations of precursors and temperatures, low relative humidity and wind speed and easterly-dominated wind direction contribute to urban ozone episodes in Hangzhou. VOCs reactivity analysis indicated that reactive alkenes like isoprene and isobutene contributed most to ozone formation. Three methods were applied to evaluate O3-VOCs-NOx sensitivity in ZH: VOCs/NOx ratio method, Smog Production Model (SPM) and Relative Incremental Reactivity (RIR). The results show that summer ozone in urban Hangzhou mostly presents VOCs-limited and transition region alternately. Our study implies that the increasing automobiles and VOCs emissions from upwind area could result in ozone pollution in urban Hangzhou, and synergistic reduction of VOCs and NOx will be more effective.

Synergistic action of tropospheric ozone and carbon dioxide on yield and nutritional quality of Indian mustard (Brassica juncea (L.) Czern.).

Science.gov (United States)

Singh, Satyavan; Bhatia, Arti; Tomer, Ritu; Kumar, Vinod; Singh, B; Singh, S D

2013-08-01

Field experiments were conducted in open top chamber during rabi seasons of 2009-10 and 2010-11 at the research farm of the Indian Agricultural Research Institute, New Delhi to study the effect of tropospheric ozone (O3) and carbon dioxide (CO2) interaction on yield and nutritional quality of Indian mustard (Brassica juncea (L.) Czern.). Mustard plants were grown from emergence to maturity under different treatments: charcoal-filtered air (CF, 80-85 % less O3 than ambient O3 and ambient CO2), nonfiltered air (NF, 5-10 % less O3 than ambient O3 and ambient CO2 ), nonfiltered air with elevated carbon dioxide (NF + CO2, NF air and 550 ± 50 ppm CO2), elevated ozone (EO, NF air and 25-35 ppb elevated O3), elevated ozone along with elevated carbon dioxide (EO + CO2, NF air, 25-35 ppb O3 and 550 ± 50 ppm CO2), and ambient chamber less control (AC, ambient O3 and CO2). Elevated O3 exposure led to reduced photosynthesis and leaf area index resulting in decreased seed yield of mustard. Elevated ozone significantly decreased the oil and micronutrient content in mustard. Thirteen to 17 ppm hour O3 exposure (accumulated over threshold of 40 ppm, AOT 40) reduced the oil content by 18-20 %. Elevated CO2 (500 ± 50 ppm) along with EO was able to counter the decline in oil content in the seed, and it increased by 11 to 13 % over EO alone. Elevated CO2, however, decreased protein, calcium, zinc, iron, magnesium, and sulfur content in seed as compared to the nonfiltered control, whereas removal of O3 from air in the charcoal-filtered treatment resulted in a significant increase in the same.

Carryover effects of acid rain and ozone on the physiology of multiple flushes of loblolly pine seedlings

International Nuclear Information System (INIS)

Sasek, T.W.; Richardson, C.J.; Fendick, E.A.; Bevington, S.R.; Kress, L.W.

1991-01-01

The effects of acid rain and ozone exposure on loblolly pine (Pinus taeda L.) seedlings in the Piedmont of North Carolina were assessed over two exposure seasons (1987-1988). Direct effects and carryover effects of long-term exposure on the photosynthetic potential and photopigment concentrations of different needle age-classes were studied. Three half-sib families were grown in open-top field chambers and exposed two acid rain treatments and five ozone exposures delivered in proportion to ambient concentrations in a complete factorial design. Ozone significantly affected photosynthesis but there were no statistically significant effects of acid rain nor any ozone x acid rain interactions. In 1987, photosynthesis of the 1987 first-flush progressively diverged among the ozone treatments except between charcoal-filtered and nonfiltered air (NF). At the end of the first season, photosynthesis was reduced 24% at 1.5x compared to CF and more than 80% at 2.25x and 3.0x. Chlorophyll and carotenoid concentrations were similarly reduced at elevated ozone exposures. In 1988, photosynthesis of the 1987 first-flush in the elevated ozone treatments remained lower. Early in the second season, the 1988 first-flush had a 25% to 50% lower photosynthetic potential at 2.25x and 3.0x compared to CF. This carryover effect on the photosynthetic potential before significant cumulative exposure was progressively smaller in the later 1988 flushes. In the late season flushes in the highest ozone treatments, photosynthesis was significantly higher than in the lower ozone treatments

Estimation of surface UV levels based on Meteor-3/TOMS ozone data

Energy Technology Data Exchange (ETDEWEB)

Borisov, Y A [Central Aerological Observatory, Moscow (Russian Federation); Geogdzhaev, I V [Moscow Inst. of Physics and Technology, Moscow (Russian Federation); Khattatov, V U [Central Aerological Observatory, Moscow (Russian Federation)

1996-12-31

The major consequence of ozone layer depletion for the environment is an increase of harmful ultraviolet (UV) radiation on the Earth surface and in the upper ocean. This implies the importance of environmental UV monitoring. Since the direct global monitoring is not currently possible, indirect estimations of surface UV levels may be used based on satellite ozone data (Madronich, S. 1992). Total Ozone Mapping Spectrometer (TOMS) on board the METEOR-3 satellite provided regular set of data for such estimates. During the time of its operation (August, 1991 - December, 1994) the instrument registered several ozone hole events over Antarctica, when ozone levels dropped by as much as 60 % from their unperturbed values. Probably even more alarming ozone depletions were observed over highly populated regions of middle latitudes of northern hemisphere. Radiative transfer modeling was used to convert METEOR-3/TOMS daily ozone values into regional and global maps of biologically active UV. Calculations demonstrate the effect on surface UV levels produced by ozone hole over Antarctica and ozone depletions over the territory of Russia (March, 1994). UV contour lines deviate from the normal appearance which is determined by growing southward solar elevation. UV contour lines are almost perpendicular to the ozone ones in the ozone depletions areas. The 30 % ozone depletion, over Siberia caused more than 30 % increase in noontime erythemal UV levels, which is equivalent to 10-15 degrees southward latitude displacement. Higher UV radiation increases were found in ozone hole over South America (October 1992) equivalent to about 20 degrees southward displacement

Estimation of surface UV levels based on Meteor-3/TOMS ozone data

Energy Technology Data Exchange (ETDEWEB)

Borisov, Y.A. [Central Aerological Observatory, Moscow (Russian Federation); Geogdzhaev, I.V. [Moscow Inst. of Physics and Technology, Moscow (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Moscow (Russian Federation)

1995-12-31

The major consequence of ozone layer depletion for the environment is an increase of harmful ultraviolet (UV) radiation on the Earth surface and in the upper ocean. This implies the importance of environmental UV monitoring. Since the direct global monitoring is not currently possible, indirect estimations of surface UV levels may be used based on satellite ozone data (Madronich, S. 1992). Total Ozone Mapping Spectrometer (TOMS) on board the METEOR-3 satellite provided regular set of data for such estimates. During the time of its operation (August, 1991 - December, 1994) the instrument registered several ozone hole events over Antarctica, when ozone levels dropped by as much as 60 % from their unperturbed values. Probably even more alarming ozone depletions were observed over highly populated regions of middle latitudes of northern hemisphere. Radiative transfer modeling was used to convert METEOR-3/TOMS daily ozone values into regional and global maps of biologically active UV. Calculations demonstrate the effect on surface UV levels produced by ozone hole over Antarctica and ozone depletions over the territory of Russia (March, 1994). UV contour lines deviate from the normal appearance which is determined by growing southward solar elevation. UV contour lines are almost perpendicular to the ozone ones in the ozone depletions areas. The 30 % ozone depletion, over Siberia caused more than 30 % increase in noontime erythemal UV levels, which is equivalent to 10-15 degrees southward latitude displacement. Higher UV radiation increases were found in ozone hole over South America (October 1992) equivalent to about 20 degrees southward displacement

Dietary restriction causes chronic elevation of corticosterone and enhances stress response in red-legged kittiwake chicks

Science.gov (United States)

Kitaysky, A.S.; Kitaiskaia, E.V.; Wingfield, J.C.; Piatt, John F.

2001-01-01

Release of corticosterone in hungry kittiwake chicks facilitates begging and allows them to restore depleted energy reserves by increasing parental food provisioning. However, in order to avoid detrimental effects of chronic elevation of corticosterone, chicks might suppress adrenocortical activity in response to prolonged food shortages. In this study we examined temporal dynamics of corticosterone release in red-legged kittiwake (Rissa brevirostris) chicks exposed to prolonged restrictions in energy content and/or nutritional quality (low versus high lipid content) of their food. Starting at the age of 15 days, chicks were fed either high- or low-lipid fish at 40%, 65%, and 100% of ad libitum energy intake. Body mass measurements and baseline plasma samples were taken on a weekly basis after beginning of the treatment. After 3 weeks of treatment, chicks were exposed to a standardized acute handling and restraint stress protocol, where in addition to a baseline sample, three plasma samples were taken at intervals up to 50 min. We found that food-restricted chicks had lower body mass, chronically (during 2-3 weeks) elevated baseline and higher acute stress-induced levels of corticosterone compared to chicks fed ad libitum. Low lipid content of food further exacerbated these effects. An increase in baseline levels of corticosterone was observed within a week after energy requirements of food-restricted chicks exceeded their daily energy intake. A tendency for suppression of adrenocortical activity was observed in treatments fed low-lipid diets only at the end of the experiment. We suggest that nest-bound chicks, if food-stressed, might suffer deleterious effects of chronic elevation of corticosterone.

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

International Nuclear Information System (INIS)

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

2010-01-01

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.

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)

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

2010-04-15

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

Ozone distribution in remote ecologically vulnerable terrain of the southern Sierra Nevada, CA

International Nuclear Information System (INIS)

Panek, Jeanne; Saah, David; Esperanza, Annie; Bytnerowicz, Andrzej; Fraczek, Witold; Cisneros, Ricardo

2013-01-01

Ozone concentration spatial patterns remain largely uncharacterized across the extensive wilderness areas of the Sierra Nevada, CA, despite being downwind of major pollution sources. These natural areas, including four national parks and four national forests, contain forest species that are susceptible to ozone injury. Forests stressed by ozone are also more vulnerable to other agents of mortality, including insects, pathogens, climate change, and ultimately fire. Here we analyze three years of passive ozone monitor data from the southern Sierra Nevada and interpolate landscape-scale spatial and temporal patterns during the summer-through-fall high ozone concentration period. Segmentation analysis revealed three types of ozone exposure sub-regions: high, low, and variable. Consistently high ozone exposure regions are expected to be most vulnerable to forest mortality. One high exposure sub-region has been documented elsewhere as being further vulnerable to increased drought and fire potential. Identifying such hot-spots of forest vulnerability has utility for prioritizing management. -- Highlights: •Three years of passive ozone sampler data over 49,000 km 2 were analyzed spatially. •Spatial and temporal ozone patterns were mapped across the Sierra Nevada, CA. •Sub-regions of consistently high, low and variable ozone exposure were identified. •The 1700–2400 m elevation band delineated a distinct break in ozone concentration. •This approach has utility for prioritizing management across vulnerable landscapes. -- A passive ozone sampler network in combination with spatial analysis techniques was used to characterize landscape-scale ozone patterns and dynamics, identifying regions of consistently high and low ozone exposure for forest management prioritization

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

International Nuclear Information System (INIS)

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

1994-01-01

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

A cloud-ozone data product from Aura OMI and MLS satellite measurements

Directory of Open Access Journals (Sweden)

J. R. Ziemke

2017-11-01

Full Text Available Ozone within deep convective clouds is controlled by several factors involving photochemical reactions and transport. Gas-phase photochemical reactions and heterogeneous surface chemical reactions involving ice, water particles, and aerosols inside the clouds all contribute to the distribution and net production and loss of ozone. Ozone in clouds is also dependent on convective transport that carries low-troposphere/boundary-layer ozone and ozone precursors upward into the clouds. Characterizing ozone in thick clouds is an important step for quantifying relationships of ozone with tropospheric H2O, OH production, and cloud microphysics/transport properties. Although measuring ozone in deep convective clouds from either aircraft or balloon ozonesondes is largely impossible due to extreme meteorological conditions associated with these clouds, it is possible to estimate ozone in thick clouds using backscattered solar UV radiation measured by satellite instruments. Our study combines Aura Ozone Monitoring Instrument (OMI and Microwave Limb Sounder (MLS satellite measurements to generate a new research product of monthly-mean ozone concentrations in deep convective clouds between 30° S and 30° N for October 2004–April 2016. These measurements represent mean ozone concentration primarily in the upper levels of thick clouds and reveal key features of cloud ozone including: persistent low ozone concentrations in the tropical Pacific of  ∼ 10 ppbv or less; concentrations of up to 60 pphv or greater over landmass regions of South America, southern Africa, Australia, and India/east Asia; connections with tropical ENSO events; and intraseasonal/Madden–Julian oscillation variability. Analysis of OMI aerosol measurements suggests a cause and effect relation between boundary-layer pollution and elevated ozone inside thick clouds over landmass regions including southern Africa and India/east Asia.

Effect of fiber material on ozone removal and carbonyl production from carpets

Science.gov (United States)

Abbass, Omed A.; Sailor, David J.; Gall, Elliott T.

2017-01-01

Indoor air quality is affected by indoor materials such as carpets that may act as sources and/or sinks of gas-phase air pollutants. Heterogeneous reactions of ozone with carpets may result in potentially harmful products. In this study, indoor residential carpets of varying fiber types were tested to evaluate their ability to remove ozone, and to assess their role in the production of carbonyls when exposed to elevated levels of ozone. Tests were conducted with six types of new unused carpets. Two sets of experiments were conducted, the first measured ozone removal and ozone deposition velocities, and the second measured primary carbonyl production and secondary production as a result of exposure to ozone. The tests were conducted using glass chambers with volume of 52 L each. Air exchange rates for all tests were 3 h-1. The ozone removal tests show that, for the conditions tested, the polyester carpet sample had the lowest ozone removal (40%), while wool carpet had the greatest ozone removal (65%). Most carpet samples showed higher secondary than primary carbonyl emissions, with carpets containing polypropylene fibers being a notable exception. Carpets with polyester fibers had both the highest primary and secondary emissions of formaldehyde among all samples tested. While it is difficult to make blanket conclusions about the relative air quality merits of various carpet fiber options, it is clear that ozone removal percentages and emissions of volatile organic compounds can vary drastically as a function of fiber type.

Unequivocal detection of ozone recovery in the Antarctic Ozone Hole through significant increases in atmospheric layers with minimum ozone

Science.gov (United States)

de Laat, Jos; van Weele, Michiel; van der A, Ronald

2015-04-01

An important new landmark in present day ozone research is presented through MLS satellite observations of significant ozone increases during the ozone hole season that are attributed unequivocally to declining ozone depleting substances. For many decades the Antarctic ozone hole has been the prime example of both the detrimental effects of human activities on our environment as well as how to construct effective and successful environmental policies. Nowadays atmospheric concentrations of ozone depleting substances are on the decline and first signs of recovery of stratospheric ozone and ozone in the Antarctic ozone hole have been observed. The claimed detection of significant recovery, however, is still subject of debate. In this talk we will discuss first current uncertainties in the assessment of ozone recovery in the Antarctic ozone hole by using multi-variate regression methods, and, secondly present an alternative approach to identify ozone hole recovery unequivocally. Even though multi-variate regression methods help to reduce uncertainties in estimates of ozone recovery, great care has to be taken in their application due to the existence of uncertainties and degrees of freedom in the choice of independent variables. We show that taking all uncertainties into account in the regressions the formal recovery of ozone in the Antarctic ozone hole cannot be established yet, though is likely before the end of the decade (before 2020). Rather than focusing on time and area averages of total ozone columns or ozone profiles, we argue that the time evolution of the probability distribution of vertically resolved ozone in the Antarctic ozone hole contains a better fingerprint for the detection of ozone recovery in the Antarctic ozone hole. The advantages of this method over more tradition methods of trend analyses based on spatio-temporal average ozone are discussed. The 10-year record of MLS satellite measurements of ozone in the Antarctic ozone hole shows a

Elevated plasma endothelin-1 and pulmonary arterial pressure in children exposed to air pollution.

Science.gov (United States)

Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J; Reed, William

2007-08-01

Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O(3) that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. We conducted a study of 81 children, 7.9 +/- 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O(3) levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 mum in aerodynamic diameter (PM(2.5)) before endothelin-1 measurement (p = 0.03). Chronic exposure of children to PM(2.5) is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure.

Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

Science.gov (United States)

Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

2007-01-01

Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

Ozonation for source treatment of pharmaceuticals in hospital wastewater - ozone lifetime and required ozone dose

DEFF Research Database (Denmark)

Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Chhetri, Ravi Kumar

2016-01-01

Ozonation aimed at removing pharmaceuticals was studied in an effluent from an experimental pilot system using staged moving bed biofilm reactor (MBBR) tanks for the optimal biological treatment of wastewater from a medical care unit of Aarhus University Hospital. Dissolved organic carbon (DOC......) and pH in samples varied considerably, and the effect of these two parameters on ozone lifetime and the efficiency of ozone in removing pharmaceuticals were determined. The pH in the effluent varied from 5.0 to 9.0 resulting in approximately a doubling of the required ozone dose at the highest p......H for each pharmaceutical. DOC varied from 6 to 20 mg-DOC/L. The ozone required for removing each pharmaceutical, varied linearly with DOC and thus, ozone doses normalized to DOC (specific ozone dose) agreed between water samples (typically within 15%). At neutral pH the specific ozone dose required...

Influence of ambient ozone on the incidence of bone fractures especially among the elderly

Energy Technology Data Exchange (ETDEWEB)

Calabrese, E.J.

1979-02-01

Elevated levels of breatheable ozone will reduce the amount of uv radiation in the range of 280 to 305 nm reaching the surface of earth. This range of uv converts the provitamin 7-dehydrocholesterol to vitamin D, within the human. Since most typical diets contain low levels of vitamin D, the role of uv-related vitamin D synthesis in the skin is considered to provide very important contributions to the total vitamin D content of the blood. Thus, elevated levels of ambient ozone should result in a decreased level of vitamin D synthesis which may be expressed as an increase in the incidence of histological osteomalacia and ultimately bone fractures, especially among the elderly.

Firing probability and mean firing rates of human muscle vasoconstrictor neurones are elevated during chronic asphyxia

DEFF Research Database (Denmark)

Ashley, Cynthia; Burton, Danielle; Sverrisdottir, Yrsa B

2010-01-01

in the obstructive sleep apnoea syndrome (OSAS) is associated with an increase in firing probability and mean firing rate, and an increase in multiple within-burst firing. Here we characterize the firing properties of muscle vasoconstrictor neurones in patients with chronic obstructive pulmonary disease (COPD), who...... are chronically asphyxic. We tested the hypothesis that this elevated chemical drive would shift the firing pattern from that seen in healthy subjects to that seen in OSAS. The mean firing probability (52%) and mean firing rate (0.92 Hz) of 17 muscle vasoconstrictor neurones recorded in COPD were comparable...

Plasma concentrations of alpha-melanocyte-stimulating hormone are elevated in patients on chronic haemodialysis.

Science.gov (United States)

Airaghi, L; Garofalo, L; Cutuli, M G; Delgado, R; Carlin, A; Demitri, M T; Badalamenti, S; Graziani, G; Lipton, J M; Catania, A

2000-08-01

Clinical and/or laboratory signs of systemic inflammation occur frequently in patients undergoing long-term haemodialysis. It is likely, therefore, that a compensatory release of endogenous anti-inflammatory molecules occurs to limit host reactions. The aim of the present research was to determine if the potent anti-inflammatory peptide alpha-melanocyte-stimulating hormone (alpha-MSH), a pro-opiomelanocortin derivative, is increased in plasma of haemodialysis patients. Because endotoxin and cytokines induce alpha-MSH in vivo and in vitro, we also measured plasma concentrations of endotoxin, interleukin-6 (IL-6), and tumour necrosis factor alpha (TNF-alpha), and the two circulating products of activated monocytes, nitric oxide (NO) and neopterin. Thirty-five chronic haemodialysis patients, 20 patients with chronic renal failure not yet on dialysis, and 35 normal controls were included in the study. In the haemodialysis group, blood samples were obtained before and at the end of a dialysis session. Plasma alpha-MSH was measured using a double antibody radioimmunoassay, and IL-6, TNF-alpha, and neopterin using specific enzyme-linked immunosorbent assays. Plasma nitrites were determined by a colorimetric method, and endotoxin with the quantitative chromogenic LAL (limulus amoebocyte lysate) method. Mean plasma alpha-MSH was higher in haemodialysis patients than in control subjects, with the peptide concentrations being particularly elevated in dialysed patients with detectable endotoxin. High alpha-MSH concentrations were observed in the pre-dialysis samples, with no substantial change at the end of the dialysis session. Plasma concentrations of IL-6, TNF-alpha, neopterin, and NO were generally elevated in chronic haemodialysis patients and there was a negative correlation between circulating alpha-MSH and IL-6. In patients with renal failure not yet on dialysis, mean plasma alpha-MSH was similar to that of normal subjects. alpha-MSH is increased in the circulation of

Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

Science.gov (United States)

Leanne M. Vigue; Richard L. Lindroth

2010-01-01

Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

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

Science.gov (United States)

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

2003-06-01

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

The interaction of ozone and nitrogen dioxide in the stratosphere of East Antarctica

Science.gov (United States)

Bruchkouski, Ilya; Krasouski, Aliaksandr; Dziomin, Victar; Svetashev, Alexander

2016-04-01

At the Russian Antarctic station "Progress" (S69°23´, E76°23´) simultaneous measurements of trace gases using the MARS-B (Multi-Axis Recorder of Spectra) instrument and PION-UV spectro-radiometer for the time period from 05.01.2014 to 28.02.2014 have been performed. Both instruments were located outdoors. The aim of the measurements was to retrieve the vertical distribution of ozone and nitrogen dioxide in the atmosphere and to study their variability during the period of measurements. The MARS-B instrument, developed at the National Ozone Monitoring Research and Education Centre of the Belarusian State University (NOMREC BSU), successfully passed the procedure of international inter-comparison campaign MAD-CAT 2013 in Mainz, Germany. The instrument is able to record the spectra of scattered sunlight at different elevation angles within a maximum aperture of 1.3°. 12 elevation angles have been used in this study, including the zenith direction. Approximately 7000 spectra per day were registered in the range of 403-486 nm, which were then processed by DOAS technique aiming to retrieve differential slant columns of ozone, nitrogen dioxide and oxygen dimer. Furthermore, total nitrogen dioxide column values have been retrieved employing the Libradtran radiative transfer model. The PION-UV spectro-radiometer, also developed at NOMREC BSU, is able to record the spectra of scattered sunlight from the hemisphere in the range of 280-430 nm. The registered spectra have been used to retrieve the total ozone column values employing the Stamnes method. In this study observational data from both instruments is presented and analyzed. Furthermore, by combining analysis of this data with model simulations it is shown that decreases in nitrogen dioxide content in the upper atmosphere can be associated with increases in total ozone column values and rising of the ozone layer upper boundary. Finally, the time delay between changes in nitrogen dioxide and ozone values is

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

International Nuclear Information System (INIS)

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

2015-01-01

When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools. - Highlights: • We examined the effects of ozone on Pieris brassicae performance and preference. • We studied ozone and herbivore induced changes in the metabolome of Brassica nigra. • The performance of P. brassicae did not correlate with preference of ozonated plants. • Ozone and herbivore-feeding stress changes the phytochemical pools of B. nigra. - Ozone indirectly reduces herbivore performance, which is associated with change in phytochemical pools, but does not correlate with host plant preference

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

Directory of Open Access Journals (Sweden)

Park Chang-Soo

2006-02-01

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

The exhibition to ozone diminishes the adherence and increases the membrane permeability of macrophages alveolar of rate

International Nuclear Information System (INIS)

Garcia, J.

2000-01-01

Ozone gas is generated photochemically in areas with high levels of automotive or industrial emissions, and causes irritation and inflammation of the airways if inhaled. Rat alveolar macrophages were obtained by lung lavage from male Sprague Dawley rats and used as a model to assess ozone induced cell damage (0,594 ppm for up to 60 minutes). Ozone exposure caused loss of cell adherence to a polystyrene substrate and increased membrane permeability, as noted by increases in specific 51 Cr release and citoplasmic calcium levels. The results indicate that the cell membrane is a target for ozone damage. Elevations of cytoplasmic calcium could mediate other macrophage responses to ozone , including eicosanoid and nitric oxide production, with concomitant decreases in phagocytic ability and superoxide production. (Author) [es

Variable performance of outbreak defoliators on aspen clones exposed to elevated CO2 and O3

Science.gov (United States)

Daniel A. Herms; William J. Mattson; David N. Karowe; Mark D. Coleman; Terry M. Trier; Bruce A. Birr; J. G. Isebrands

1996-01-01

Increasing atmospheric concentrations of ozone and CO2 affect many aspects of tree physiology. However, their effects on tree resistance to insects have received relatively little attention. The objectives of this study were to test the effects of elevated CO2 and ozone on the resistance of three quaking aspen (...

Ozone Layer Protection

Science.gov (United States)

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

Passive Adsorption of Volatile Monoterpene in Pest Control: Aided by Proximity and Disrupted by Ozone.

Science.gov (United States)

Mofikoya, Adedayo O; Kim, Tae Ho; Abd El-Raheem, Ahmed M; Blande, James D; Kivimäenpää, Minna; Holopainen, Jarmo K

2017-11-08

Plant volatiles mediate a range of interactions across and within trophic levels, including plant-plant interactions. Volatiles emitted by a plant may trigger physiological responses in neighboring plants or adhere to their surfaces, which, in turn, may affect the responses of the neighboring plant to herbivory. These volatiles are subject to chemical reactions during transport in air currents, especially in a polluted atmosphere. We conducted a field experiment to test for the adsorption of dispenser-released myrcene on the surfaces of cabbage plants and the effects of distance from the dispenser and elevated ozone levels (1.4× ambient) on the process. We also tested the effects of the same treatments on oviposition on cabbage plants by naturally occurring Plutella xylostella. Under low ambient ozone conditions of central Finland, there was evidence for the adsorption and re-release of myrcene by cabbage plants growing at a distance of 50 cm from myrcene dispensers. This effect was absent at elevated ozone levels. The number of eggs deposited by P. xylostella was generally lower in plots under elevated ozone compared to ambient control plots. Our results indicate that passive adsorption and re-release of a volatile monoterpene can occur in nature; however, this process is dependent upon the distance between emitter source and receiver plants as well as the concentration of atmospheric pollutants in the air. We conclude that, in the development of field-scale use of plant volatiles in modern pest control, the effects of distances and air pollution should be considered.

Effect of ozone and histamine on airway permeability to horseradish peroxidase in guinea pigs

International Nuclear Information System (INIS)

Miller, P.D.; Gordon, T.; Warnick, M.; Amdur, M.O.

1986-01-01

Airway permeability was studied in groups of male guinea pigs at 2, 8, and 24 h after a 1-h exposure to 1 ppm ozone or at 2 h after a 1-h exposure to filtered air (control). Intratracheal administration of 2 mg horseradish peroxidase (HRP) was followed by blood sampling at 5-min intervals up to 30 min. The rate of appearance of HRP in plasma was significantly higher at 2 and 8 h after ozone exposure than that found in animals examined 2 h after air exposure or 24 h after ozone exposure. A dose of 0.12 mg/kg of subcutaneous histamine given after the 15 min blood sample significantly increased the already elevated permeability seen at 2 h post ozone, but had no effect on animals exposed to filtered air 2 h earlier or to ozone 24 h earlier. No difference was seen in the amount of subcutaneous radiolabeled histamine in the lungs of animals exposed 2 h earlier either to air or to ozone. These data indicate that a short-term exposure to ozone produced a reversible increase in respiratory epithelial permeability to HRP in guinea pigs. The potentiation of this increased permeability by histamine may be another manifestation of ozone-induced hyperreactivity

Comparative study of ozonized olive oil and ozonized sunflower oil

Directory of Open Access Journals (Sweden)

Díaz Maritza F.

2006-01-01

Full Text Available In this study the ozonized olive and sunflower oils are chemical and microbiologically compared. These oils were introduced into a reactor with bubbling ozone gas in a water bath at room temperature until they were solidified. The peroxide, acidity and iodine values along with antimicrobial activity were determined. Ozonization effects on the fatty acid composition of these oils were analyzed using Gas-Liquid Chromatographic Technique. An increase in peroxidation and acidity values was observed in both oils but they were higher in ozonized sunflower oil. Iodine value was zero in ozonized olive oil whereas in ozonized sunflower was 8.8 g Iodine per 100 g. The antimicrobial activity was similar for both ozonized oils except for Minimum Bactericidal Concentrations of Pseudomona aeruginosa. Composition of fatty acids in both ozonized oils showed gradual decrease in unsaturated fatty acids (C18:1, C18:2 with gradual increase in ozone doses.

Antarctic ozone loss in 1989-2010: evidence for ozone recovery?

Science.gov (United States)

Kuttippurath, J.; Lefèvre, F.; Pommereau, J.-P.; Roscoe, H. K.; Goutail, F.; Pazmiño, A.; Shanklin, J. D.

2012-04-01

We present a detailed estimation of chemical ozone loss in the Antarctic polar vortex from 1989 to 2010. The analyses include ozone loss estimates for 12 Antarctic ground-based (GB) stations. All GB observations show minimum ozone in the late September-early October period. Among the stations, the lowest minimum ozone values are observed at South Pole and the highest at Dumont d'Urville. The ozone loss starts by mid-June at the vortex edge and then progresses towards the vortex core with time. The loss intensifies in August-September, peaks by the end of September-early October, and recovers thereafter. The average ozone loss in the Antarctic is revealed to be about 33-50% in 1989-1992 in agreement with the increase in halogens during this period, and then stayed at around 48% due to saturation of the loss. The ozone loss in the warmer winters (e.g. 2002, and 2004) is lower (37-46%) and in the colder winters (e.g. 2003, and 2006) is higher (52-55%). Because of small inter-annual variability, the correlation between ozone loss and the volume of polar stratospheric clouds yields ~0.51. The GB ozone and ozone loss values are in good agreement with those found from the space-based observations of the Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and the Aura Microwave Limb Sounder (MLS), where the differences are within ±5% and are mostly within the error bars of the measurements. The piece-wise linear trends computed from the September-November vortex average GB and TOMS/OMI ozone show about -4 to -5.6 DU (Dobson Unit) yr-1 in 1989-1996 and about +1 DU yr-1 in 1997-2010. The trend during the former period is significant at 95% confidence intervals, but the trend in 1997-2010 is significant only at 85% confidence intervals. Our analyses suggest a period of about 9-10 yr to get the first detectable ozone

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

DEFF Research Database (Denmark)

Weschler, Charles J.

2006-01-01

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

Ozone modeling within plasmas for ozone sensor applications

OpenAIRE

Arshak, Khalil; Forde, Edward; Guiney, Ivor

2007-01-01

peer-reviewed Ozone (03) is potentially hazardous to human health and accurate prediction and measurement of this gas is essential in addressing its associated health risks. This paper presents theory to predict the levels of ozone concentration emittedfrom a dielectric barrier discharge (DBD) plasma for ozone sensing applications. This is done by postulating the kinetic model for ozone generation, with a DBD plasma at atmospheric pressure in air, in the form of a set of rate equations....

Urban and Rural Ozone Collect over Lusaka (Zambia, 15.5 S, 28 E) during SAFARI-2000 (September 2000)

Science.gov (United States)

Thompson, Anne M.; Witte, Jacquelyn C.; Freiman, M. Tai; Phalane, N. Agnes; Coetzee, Gert J. R.

2002-01-01

In early September, throughout south central Africa, seasonal clearing of dry vegetation and the production of charcoal for cooking leads to intense smoke haze and ozone formation. Ozone soundings made over Lusaka in early September 2000 recorded layers of high ozone (greater than 125 ppbv at 5 km) during two stagnant periods, broken by a frontal passage that reduced boundary layer ozone by 30%. During the 6-day measurement period, surface ozone concentrations ranged from 50-95 ppbv and integrated tropospheric ozone from the soundings was 39-54 Dobson Units (note 1.3 km elevation at the launch site). A stable layer of high ozone at 2-5 km was advected from rural burning regions in western Zambia and neighboring countries, making Lusaka a collection point for transboundary pollution. This is confirmed by trajectories that show ozone leaving Angola, Namibia, Botswana and South Africa before heading toward the Indian Ocean and returning to Lusaka via Mozambique and Zimbabwe. Ozone in the mixed layer at Lusaka is heavily influenced by local sources.

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-09-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs

Science.gov (United States)

Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico

2016-01-01

Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs. PMID:26837703

Evaluation of ozone injury on foliage of black cherry (Prunus serotina) and tall milkweed (Asclepias exaltata) in Great Smoky Mountains National Park.

Science.gov (United States)

Chappelka, A; Renfro, J; Somers, G; Nash, B

1997-01-01

The incidence and severity of visible foliar ozone injury on black cherry (Prunus serotina) seedlings and saplings and tall milkweed (Asclepias exaltata) plants in Great Smoky Mountains National Park (GRSM) were determined by surveys along selected trails conducted during late summer 1992. The incidence (% injured plants) of ozone injury on black cherry was 47% and the percent injured leaves/injured plant and average leaf area injured were 43 and 6%, respectively. Maximum severity (avg. leaf area of the most severely injured leaf) was 12%. Black cherry seedlings and saplings exhibiting ozone injury were taller than non-injured plants. When insect feeding was present, it occurred 96% of the time on plants with ozone injury. Significantly more injury (p=0.007) on black cherry (% injured leaves/injured black cherry) occurred in the NW section of GRSM compared with the other Park sections. Regression analyses showed no relationships in ozone injury with respect to aspect, slope or elevation. Tall milkweed was evaluated twice during August for ozone injury. The incidence (% injured plants) of ozone injury was 74 and 79% for the first and second survey, respectively. The percentage of injured leaves per plant from the first to second survey was 63 to 79%, respectively. Tall milkweeds showing ozone injury were taller than the non-injured plants. The percentage of insect-damaged plants was 50% among plants without ozone injury and 60% among ozone-injured plants. Non-injured tall milkweed had fewer flowers and/or pods than the injured plants. Mean leaf area injured increased over time, and mean maximum leaf area injured increased from 8 to 11% during the same period. Regression analyses showed no differences in ozone injury regarding aspect, slope or elevation. Our findings indicate that ozone injury is widespread throughout the Park on sensitive vegetation.

Ozone decomposition

Directory of Open Access Journals (Sweden)

Batakliev Todor

2014-06-01

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

Growth responses of Populus tremuloides clones to interacting elevated carbon dioxide and tropospheric ozone

Science.gov (United States)

J. G. Isebrands; E. P. McDonald; E. Kruger; G. Hendrey; K. Percy; K. Pregitzer; J. Sober; D. F. Karnosky

2001-01-01

The Intergovernmental Panel of Climate Change (IPCC) has concluded that the greenhouse gases carbon dioxide (CO2) and tropospheric ozone (O3) are increasing concomitantly globally. Little is known about the effect of these interacting gases on growth, survival, and productivity of forest ecosystems. In this study we assess...

Ground-level ozone pollution and its health impacts in China

Science.gov (United States)

Liu, Huan; Liu, Shuai; Xue, Boru; Lv, Zhaofeng; Meng, Zhihang; Yang, Xiaofan; Xue, Tao; Yu, Qiao; He, Kebin

2018-01-01

In recent years, ground-level ozone pollution in China has become an increasingly prominent problem. This study simulated and analyzed spatiotemporal distribution of ozone and exposure level by the Weather Research and Forecasting (WRF)-Community Multiscale Air Quality (CMAQ) models and monitoring data from 1516 national air quality monitoring stations in China during 2015. The simulation results show that the Sichuan Basin, Shandong, Shanxi, Henan, Anhui, Qinghai-Tibetan Plateau, Yangtze River Delta (YRD), Pearl River Delta (PRD) and Beijing-Tianjin-Hebei (BTH) region had relatively high average annual concentrations of ozone. The regions with more than 10% nonattainment days of 160 μg/m3 (daily maximum 8-h) are mainly concentrated in BTH, Shandong Peninsula and YRD, where large seasonal variations were also found. Exposure levels were calculated based on population data and simulated ozone concentrations. The cumulative population exposed to daily maximum 8-h concentration greater than or equal to 100 μg/m3 was 816.04 million, 61.17% of the total. Three methods were used to estimate the mortality of chronic obstructive pulmonary disease (COPD) attributable to ozone. A comparative study using different exposure concentrations and threshold concentrations found large variations among these methods, although they were all peer-reviewed methods. The estimated mortality of COPD caused by ozone in China in 2015 ranged from 55341 to 80280, which mainly distributed in Beijing, Shandong, Henan, Hubei and Sichuan Province, the YRD and PRD region.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-11-15

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

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

Energy Technology Data Exchange (ETDEWEB)

Yuska, D.E.; Skelly, J.M.; Ferdinand, J.A.; Stevenson, R.E.; Savage, J.E.; Mulik, J.D.; Hines, A

2003-09-01

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

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

International Nuclear Information System (INIS)

Yuska, D.E.; Skelly, J.M.; Ferdinand, J.A.; Stevenson, R.E.; Savage, J.E.; Mulik, J.D.; Hines, A.

2003-01-01

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

Elevated CO2 plus chronic warming reduce nitrogen uptake and levels or activities of nitrogen-uptake and -assimilatory proteins in tomato roots.

Science.gov (United States)

Jayawardena, Dileepa M; Heckathorn, Scott A; Bista, Deepesh R; Mishra, Sasmita; Boldt, Jennifer K; Krause, Charles R

2017-03-01

Atmospheric CO 2 enrichment is expected to often benefit plant growth, despite causing global warming and nitrogen (N) dilution in plants. Most plants primarily procure N as inorganic nitrate (NO 3 - ) or ammonium (NH 4 + ), using membrane-localized transport proteins in roots, which are key targets for improving N use. Although interactive effects of elevated CO 2 , chronic warming and N form on N relations are expected, these have not been studied. In this study, tomato (Solanum lycopersicum) plants were grown at two levels of CO 2 (400 or 700 ppm) and two temperature regimes (30 or 37°C), with NO 3 - or NH 4 + as the N source. Elevated CO 2 plus chronic warming severely inhibited plant growth, regardless of N form, while individually they had smaller effects on growth. Although %N in roots was similar among all treatments, elevated CO 2 plus warming decreased (1) N-uptake rate by roots, (2) total protein concentration in roots, indicating an inhibition of N assimilation and (3) shoot %N, indicating a potential inhibition of N translocation from roots to shoots. Under elevated CO 2 plus warming, reduced NO 3 - -uptake rate per g root was correlated with a decrease in the concentration of NO 3 - -uptake proteins per g root, reduced NH 4 + uptake was correlated with decreased activity of NH 4 + -uptake proteins and reduced N assimilation was correlated with decreased concentration of N-assimilatory proteins. These results indicate that elevated CO 2 and chronic warming can act synergistically to decrease plant N uptake and assimilation; hence, future global warming may decrease both plant growth and food quality (%N). © 2016 Scandinavian Plant Physiology Society.

Interaction effects of temperature and ozone on lung function and markers of systemic inflammation, coagulation, and fibrinolysis: A crossover study of healthy young volunteers

Science.gov (United States)

BACKGROUND: Trends in climate suggest that extreme weather events such as heat waves will become more common. High levels of the gaseous pollutant ozone are associated with elevated temperatures. Ozone has been associated with respiratory diseases as well as cardiovascular morbid...

Ozone decay in chemical reactor for ozone-dynamical disintegration of used tyres

International Nuclear Information System (INIS)

Golota, V.I.; Manuilenko, O.V.; Taran, G.V.; Dotsenko, Yu.V.; Pismenetskii, A.S.; Zamuriev, A.A.; Benitskaja, V.A.

2011-01-01

The ozone decay kinetics in the chemical reactor intended for used tyres disintegration is investigated experimentally and theoretically. Ozone was synthesized in barrierless ozonizers based on the streamer discharge. The chemical reactor for tyres disintegration in the ozone-air environment represents the cylindrical chamber, which feeds from the ozonizer by ozone-air mixture with the specified rate of volume flow, and with known ozone concentration. The output of the used mixture, which rate of volume flow is also known, is carried out through the ozone destructor. As a result of ozone decay in the volume and on the reactor walls, and output of the used mixture from the reactor, the ozone concentration in the reactor depends from time. In the paper, the analytical expression for dependence of ozone concentration in the reactor from time and from the parameters of a problem such as the volumetric feed rate, ozone concentration on the input in the reactor, volume flow rate of the used mixture, the volume of the reactor and the area of its internal surface is obtained. It is shown that experimental results coincide with good accuracy with analytical ones.

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

DEFF Research Database (Denmark)

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

2006-01-01

within local networks were relatively small, but seasonal and inter-annual differences were strong due to the variability of meteorological conditions and related ozone concentrations. The 2001 data revealed a significant relationship between foliar injury degree and various descriptors of ozone...... pollution such as mean value, AOT20 and AOT40. Examining individual sites of the local monitoring networks separately, however, yielded noticeable differences. Some sites showed no association between ozone pollution and ozone-induced effects, whereas others featured almost linear relationships...

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

Science.gov (United States)

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

2014-01-01

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

Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens.

Science.gov (United States)

de Ondarza, José

2017-01-01

Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia 's virulence genes and defenses is therefore valuable. Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 - 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H 2 O 2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens .

Tropospheric Ozone and Photochemical Smog

Science.gov (United States)

Sillman, S.

2003-12-01

emitted species, in a process that is driven by sunlight and is accelerated by warm temperatures. This smog is largely the product of gasoline-powered engines (especially automobiles), although coal-fired industry can also generate photochemical smog. The process of photochemical smog formation was first identified by Haagen-Smit and Fox (1954) in association with Los Angeles, a city whose geography makes it particularly susceptible to this type of smog formation. Sulfate aerosols and organic particulates are often produced concurrently with ozone, giving rise to a characteristic milky-white haze associated with this type of air pollution.Today ozone and particulates are recognized as the air pollutants that are most likely to affect human health adversely. In the United States, most major metropolitan areas have periodic air pollution events with ozone in excess of government health standards. Violations of local health standards also occur in major cities in Canada and in much of Europe. Other cities around the world (especially Mexico City) also experience very high ozone levels. In addition to urban-scale events, elevated ozone occurs in region-wide events in the eastern USA and in Western Europe, with excess ozone extending over areas of 1,000 km2 or more. Ozone plumes of similar extent are found in the tropics (especially in Central Africa) at times of high biomass burning (e.g., Jenkins et al., 1997; Chatfield et al., 1998). In some cases ozone associated with biomass burning has been identified at distances up to 104 km from its sources (Schultz et al., 1999).Ozone also has a significant impact on the global troposphere, and ozone chemistry is a major component of global tropospheric chemistry. Global background ozone concentrations are much lower than urban or regional concentrations during pollution events, but there is evidence that the global background has increased as a result of human activities (e.g., Wang and Jacob, 1998; Volz and Kley, 1988). A rise in

CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

Science.gov (United States)

This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

The response of some common Egyptian plants to ozone and their use as biomonitors.

Science.gov (United States)

El-Khatib, A A

2003-01-01

Relative sensitivity of five common Egyptian plant species namely, Senecio vulgaris, Malva parviflora, Sonchus oleraceus, Medicago sativa and Melilotus indicus to elevated levels of ozone has been studied. The plants were exposed to charcoal filtered air (CFA) and different levels of O3 (50 and 100 ppb) for 5 h per day. The studied parameters were recorded for five consecutive days after fumigation. The foliar injury varied significantly among species in a dose-dependent manner. Severe injury symptoms were recorded on the leaves of M. sativa. With the exception of M. parviflora, all species exhibited significant increases in the percentage reduction of the above-ground dry weight as a result of reductions in both leaf and stem dry weights. M. sativa showed a marked reduction in its relative growth rate at elevated levels of O3. The extent of chlorophyll a destruction was higher in both M. sativa and S. oleraceus than in the other species tested. No differences in the sensitivity of chlorophylls a+b and carotenoids to ozone levels were recorded in this work. Percentage reduction of ascorbic acid was higher in M. sativa and S. oleraceus, compared with the other species studied. With respect to relative percentages of proline, there was a significant difference in the responses of plants to ozone. According to the ozone resistance (R%), measured as relative growth rate, the test species were arranged in the descending order: M. parviflora>M. Indicus>S. Vulgaris>S. Oleraceus>M. sativa. In M. sativa, both determinant and correlation coefficients are well reflected in the relationship between its physiological response, its performance and ozone levels, supporting its recommendation as a candidate for biomonitoring in Egypt.

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Development of Compact Ozonizer with High Ozone Output by Pulsed Power

Science.gov (United States)

Tanaka, Fumiaki; Ueda, Satoru; Kouno, Kanako; Sakugawa, Takashi; Akiyama, Hidenori; Kinoshita, Youhei

Conventional ozonizer with a high ozone output using silent or surface discharges needs a cooling system and a dielectric barrier, and therefore becomes a large machine. A compact ozonizer without the cooling system and the dielectric barrier has been developed by using a pulsed power generated discharge. The wire to plane electrodes made of metal have been used. However, the ozone output was low. Here, a compact and high repetition rate pulsed power generator is used as an electric source of a compact ozonizer. The ozone output of 6.1 g/h and the ozone yield of 86 g/kWh are achieved at 500 pulses per second, input average power of 280 W and an air flow rate of 20 L/min.

Is it true that ozone is always toxic? The end of a dogma

International Nuclear Information System (INIS)

Bocci, Velio

2006-01-01

There are a number of good experimental studies showing that exposure by inhalation to prolonged tropospheric ozone damages the respiratory system and extrapulmonary organs. The skin, if extensively exposed, may also contribute to the damage. The undoubtful strong reactivity of ozone has contributed to establish the dogma that ozone is always toxic and its medical application must be proscribed. Although it is less known, judiciously practiced ozonetherapy is becoming very useful either on its own or applied in combination with orthodox medicine in a broad range of pathologies. The opponents of ozonetherapy base their judgment on the ozone chemistry, and physicians, without any knowledge of the problem, are often skeptical. During the last 15 years, a clear understanding of the action of ozone in biology and medicine has been gained, allowing today to argue if it is true that ozone is always toxic. The fundamental points that are discussed in this paper are: the topography, anatomical and biochemical characteristics of the organs daily exposed to ozone versus the potent antioxidant capacity of blood exposed to a small and precisely calculated dose of ozone only for a few minutes. It is becoming clear how the respiratory system undergoing a chronic oxidative stress can release slowly, but steadily, a huge amount of toxic compounds able to enter the circulation and cause serious damage. The aim of this paper is to objectively evaluate this controversial issue

Ozone Therapy on Rats Submitted to Subtotal Nephrectomy: Role of Antioxidant System

Directory of Open Access Journals (Sweden)

José Luis Calunga

2005-01-01

Full Text Available Chronic renal failure (CRF represents a world health problem. Ozone increases the endogenous antioxidant defense system, preserving the cell redox state. The aim of this study is to evaluate the effect of ozone/oxygen mixture in the renal function, morphology, and biochemical parameters, in an experimental model of CRF (subtotal nephrectomy. Ozone/oxygen mixture was applied daily, by rectal insufflation (0.5 mg/kg for 15 sessions after the nephrectomy. Renal function was evaluated, as well as different biochemical parameters, at the beginning and at the end of the study (10 weeks. Renal plasmatic flow (RPF, glomerular filtration rate (GFR, the urine excretion index, and the sodium and potassium excretions (as a measurement of tubular function in the ozone group were similar to those in Sham group. Nevertheless, nephrectomized rats without ozone (positive control group showed the lowest RPF, GFR, and urine excretion figures, as well as tubular function. Animals treated with ozone showed systolic arterial pressure (SAP figures lower than those in the positive control group, but higher values compared to Sham group. Serum creatinine values and protein excretion in 24 hours in the ozone group were decreased compared with nephrectomized rats, but were still higher than normal values. Histological study demonstrated that animals treated with ozone showed less number of lesions in comparison with nephrectomized rats. Thiobarbituric acid reactive substances were significantly increased in nephrectomized and ozone-treated nephrectomized rats in comparison with Sham group. In the positive control group, superoxide dismutase (SOD and catalase (CAT showed the lowest figures in comparison with the other groups. However, ozone/oxygen mixture induced a significant stimulation in the enzymatic activity of CAT, SOD, and glutathione peroxidase, as well as reduced glutathione in relation with Sham and positive control groups. In this animal model of CRF, ozone

The maintenance of elevated active chlorine levels in the Antarctic lower stratosphere through HCl null cycles

Science.gov (United States)

Müller, Rolf; Grooß, Jens-Uwe; Mannan Zafar, Abdul; Robrecht, Sabine; Lehmann, Ralph

2018-03-01

The Antarctic ozone hole arises from ozone destruction driven by elevated levels of ozone destroying (active) chlorine in Antarctic spring. These elevated levels of active chlorine have to be formed first and then maintained throughout the period of ozone destruction. It is a matter of debate how this maintenance of active chlorine is brought about in Antarctic spring, when the rate of formation of HCl (considered to be the main chlorine deactivation mechanism in Antarctica) is extremely high. Here we show that in the heart of the ozone hole (16-18 km or 85-55 hPa, in the core of the vortex), high levels of active chlorine are maintained by effective chemical cycles (referred to as HCl null cycles hereafter). In these cycles, the formation of HCl is balanced by immediate reactivation, i.e. by immediate reformation of active chlorine. Under these conditions, polar stratospheric clouds sequester HNO3 and thereby cause NO2 concentrations to be low. These HCl null cycles allow active chlorine levels to be maintained in the Antarctic lower stratosphere and thus rapid ozone destruction to occur. For the observed almost complete activation of stratospheric chlorine in the lower stratosphere, the heterogeneous reaction HCl + HOCl is essential; the production of HOCl occurs via HO2 + ClO, with the HO2 resulting from CH2O photolysis. These results are important for assessing the impact of changes of the future stratospheric composition on the recovery of the ozone hole. Our simulations indicate that, in the lower stratosphere, future increased methane concentrations will not lead to enhanced chlorine deactivation (through the reaction CH4 + Cl → HCl + CH3) and that extreme ozone destruction to levels below ≈ 0.1 ppm will occur until mid-century.

Secondary maxima in ozone profiles

Directory of Open Access Journals (Sweden)

R. Lemoine

2004-01-01

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

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

Science.gov (United States)

Tai, A. P. K.

2016-12-01

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

Long-term effects of elevated ozone and UV-B radiation on vegetation and methane dynamics in northern peatland ecosystems

Energy Technology Data Exchange (ETDEWEB)

Morsky, S.K.

2012-06-15

In the stratosphere, ozone (O{sub 3}) forms an effective barrier against high energy ultraviolet radiation (UV), which is harmful to living cells. Despite the stratospheric O{sub 3} layer recovering due to international agreements, seasonal O{sub 3} depletion periods with high UV-B levels, may still occur, especially in the Polar regions. In the troposphere, O{sub 3} is a significant greenhouse gas contributing to global warming and also causing oxidative stress to animal- and plant cells. Global tropospheric O{sub 3} concentration has approximately doubled during the last century and the same trend is expected to continue. Northern peatlands are sinks of atmospheric carbon dioxide (CO{sub 2}) and sources of the powerful greenhouse gas methane (CH{sub 4}). Two multi-year open-field experiments were conducted to study the effects of elevated O{sub 3} concentration and UV-B radiation on peatland vegetation and CH{sub 4} dynamics in Finland. Peatland microcosms were used in the O{sub 3} experiment and the UV-B exposure study was conducted on a natural fen. Elevated O{sub 3} concentration significantly increased leaf cross-sections and the total number of Eriophorum vaginatum leaves towards the end of the experiment, but did not affect relative length growth, stomatal density or volume of aerenchymatous tissue of leaves. Elevated O{sub 3} did not affect relative length growth of Sphagnum papillosum shoots either. Concentrations of chlorophylls or carotenoids in E. vaginatum leaves or in S. papillosum shoots were not changed under elevated O{sub 3}. During the first growing season, elevated O{sub 3} concentration decreased methanol-extractable, UV-absorbing compounds in E. vaginatum leaves. Elevated O{sub 3} increased concentrations of organic acids and microbial biomass (estimated by phospholipid fatty acid biomarkers) in peat during the third growing season. In the first growing season net CH{sub 4} emission was temporarily decreased by elevated O{sub 3} concentration

The stratospheric ozone and the ozone layer

International Nuclear Information System (INIS)

Zea Mazo, Jorge Anibal; Leon Aristizabal Gloria Esperanza; Eslava Ramirez Jesus Antonio

2000-01-01

An overview is presented of the principal characteristics of the stratospheric ozone in the Earth's atmosphere, with particular emphasis on the tropics and the ozone hole over the poles. Some effects produced in the atmosphere as a consequence of the different human activities will be described, and some data on stratospheric ozone will be shown. We point out the existence of a nucleus of least ozone in the tropics, stretching from South America to central Africa, with annual mean values less than 240 DU, a value lower than in the middle latitudes and close to the mean values at the South Pole. The existence of such a minimum is confirmed by mean values from measurements made on satellites or with earthbound instruments, for different sectors in Colombia, like Medellin, Bogota and Leticia

Ozone impact on vegetation: phenolic metabolism modification and oxidative alteration of Rubisco in Phaseolus vulgaris L; Impact de l'ozone sur le vegetal: modification du metabolisme phenolique et alteration de la Rubisco chez Phaseolus vulgaris L.

Energy Technology Data Exchange (ETDEWEB)

Kanoun, M.

2002-04-15

In order to characterize and quantify, in semi-natural situation, the incidence of atmospheric pollution on some physiological and metabolic functions in plants, the aim of our work was to identify sub-cellular impact markers, in bean (Phaseolus vulgaris L.), able to characterize a chronic and realistic ozone pollution climate. Two criteria were chosen: the foliar phenolic metabolism and the Rubisco, the key enzyme of photosynthesis. Using Open Top Chambers system, we demonstrated that, according to concentration, exposure kinetic and leaf type, ozone could induce amount variations of some constitutive soluble phenolic and the synthesis of new phenolic (iso-flavonoids). In some cases, these disturbances were observed jointly with foliar injuries and/or biomass reduction. Concurrently, this chronic and moderate ozone exposure could also induce carbonyl formation in amino acid residues constitutive of Rubisco small subunit (Rubisco-SSU) and a reduction in the amount of the native Rubisco. The amount of a constitutive kaempferol glucuronide and the ozone-induced oxidative alteration of Rubisco-SSU were selected and tested for the construction of dose-response relationships. Whatever the marker, the linear model was able to describe the relation. For the phenolic response, several exposure indexes were tested. According to their mode of calculation, these exposure forms emphasize more or less the contribution of high ozone concentrations. If, for Rubisco oxidation, the use of the exposure index AOT40 seems relevant, in the case of the phenolic marker, the choice of the right index is leaf type dependant. (author)

NRF2 activation is involved in ozonated human serum upregulation of HO-1 in endothelial cells

International Nuclear Information System (INIS)

Pecorelli, Alessandra; Bocci, Velio; Acquaviva, Alessandra; Belmonte, Giuseppe; Gardi, Concetta; Virgili, Fabio; Ciccoli, Lucia; Valacchi, Giuseppe

2013-01-01

During the last decade, it has been shown that the activation of NRF2 and the binding to electrophile-responsive element (EpREs), stimulates the expression of a great number of genes responsible for the synthesis of phase I and phase II proteins, including antioxidants enzymes and heme oxygenase-1 (HO-1). This critical cell response occurs in cardiovascular, degenerative and chronic infective diseases aggravated by a chronic oxidative stress. In our previous reports we have shown that ozonated plasma is able to up-regulate HO-1 expression in endothelial cells. In the present work we investigated a candidate mechanism involved in this process. After treatment with increasing doses of ozonated serum (20, 40 and 80 μg/mL O 3 per mL of serum), a clear dose dependent activation of NRF2 and the subsequent induction of HO-1 and NAD(P)H quinone oxidoreductase 1(NQO1) was observed. This effect was also present when cells were treated with serum and hydrogen peroxide (H 2 O 2 ) or serum and 4-hydroxynonenal (4HNE). Moreover, the treatment with ozonated serum was associated with a dose-dependent activation of extracellular-signal-regulated kinases (ERK1/2) and p38 MAP kinases (p38), not directly involved in NRF2 activation. These data, provide a new insight on the mechanism responsible for the induction of HO-1 expression by ozonated serum in the endothelium, and have a practical importance as an expedient approach to the treatment of patients with both effective orthodox drugs and ozonated autohemotherapy, targeted to the restoration of redox homeostasis. - Highlights: ► Endothelial HO1 is upregulated by ozonated plasma ► This activation is induced by NRF2 and it is ERK independent. ► 4HNE and H 2 O 2 are the main molecules involved in this process. ► Ozonated plasma induced a hormetic effect ► Combination of orthodox medicine and ozonated plasma can be a useful treatment

NRF2 activation is involved in ozonated human serum upregulation of HO-1 in endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Pecorelli, Alessandra [Department of Molecular and Developmental Medicine, University of Siena (Italy); Child Neuropsychiatry Unit, University Hospital, AOUS, Siena (Italy); Bocci, Velio [Department of Physiology, University of Siena (Italy); Acquaviva, Alessandra [Department of Molecular and Developmental Medicine, University of Siena (Italy); Belmonte, Giuseppe [Department of Biomedical Sciences, University of Siena (Italy); Gardi, Concetta [Department of Molecular and Developmental Medicine, University of Siena (Italy); Virgili, Fabio [INRAN, Rome (Italy); Ciccoli, Lucia [Department of Molecular and Developmental Medicine, University of Siena (Italy); Valacchi, Giuseppe, E-mail: giuseppe.valacchi@unife.it [Department of Life Sciences and Biotechnology, University of Ferrara (Italy); Department of Food and Nutrition, Kyung Hee University, Seoul (Korea, Republic of)

2013-02-15

During the last decade, it has been shown that the activation of NRF2 and the binding to electrophile-responsive element (EpREs), stimulates the expression of a great number of genes responsible for the synthesis of phase I and phase II proteins, including antioxidants enzymes and heme oxygenase-1 (HO-1). This critical cell response occurs in cardiovascular, degenerative and chronic infective diseases aggravated by a chronic oxidative stress. In our previous reports we have shown that ozonated plasma is able to up-regulate HO-1 expression in endothelial cells. In the present work we investigated a candidate mechanism involved in this process. After treatment with increasing doses of ozonated serum (20, 40 and 80 μg/mL O{sub 3} per mL of serum), a clear dose dependent activation of NRF2 and the subsequent induction of HO-1 and NAD(P)H quinone oxidoreductase 1(NQO1) was observed. This effect was also present when cells were treated with serum and hydrogen peroxide (H{sub 2}O{sub 2}) or serum and 4-hydroxynonenal (4HNE). Moreover, the treatment with ozonated serum was associated with a dose-dependent activation of extracellular-signal-regulated kinases (ERK1/2) and p38 MAP kinases (p38), not directly involved in NRF2 activation. These data, provide a new insight on the mechanism responsible for the induction of HO-1 expression by ozonated serum in the endothelium, and have a practical importance as an expedient approach to the treatment of patients with both effective orthodox drugs and ozonated autohemotherapy, targeted to the restoration of redox homeostasis. - Highlights: ► Endothelial HO1 is upregulated by ozonated plasma ► This activation is induced by NRF2 and it is ERK independent. ► 4HNE and H{sub 2}O{sub 2} are the main molecules involved in this process. ► Ozonated plasma induced a hormetic effect ► Combination of orthodox medicine and ozonated plasma can be a useful treatment.

Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

International Nuclear Information System (INIS)

Noormets, Asko; Kull, Olevi; Sober, Anu; Kubiske, Mark E.; Karnosky, David F.

2010-01-01

The effect of elevated CO 2 and O 3 on apparent quantum yield (φ), maximum photosynthesis (P max ), carboxylation efficiency (V cmax ) and electron transport capacity (J max ) at different canopy locations was studied in two aspen (Populus tremuloides) clones of contrasting O 3 tolerance. Local light climate at every leaf was characterized as fraction of above-canopy photosynthetic photon flux density (%PPFD). Elevated CO 2 alone did not affect φ or P max , and increased J max in the O 3 -sensitive, but not in the O 3 -tolerant clone. Elevated O 3 decreased leaf chlorophyll content and all photosynthetic parameters, particularly in the lower canopy, and the negative impact of O 3 increased through time. Significant interaction effect, whereby the negative impact of elevated O 3 was exaggerated by elevated CO 2 was seen in Chl, N and J max , and occurred in both O 3 -tolerant and O 3 -sensitive clones. The clonal differences in the level of CO 2 x O 3 interaction suggest a relationship between photosynthetic acclimation and background O 3 concentration. - Photosynthetic acclimation to elevated CO 2 depends on the background oxidant levels.

Heterogeneous catalytic ozonation of ciprofloxacin in water with carbon nanotube supported manganese oxides as catalyst

Energy Technology Data Exchange (ETDEWEB)

Sui, Minghao, E-mail: suiminghao.sui@gmail.com [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Xing, Sichu; Sheng, Li; Huang, Shuhang; Guo, Hongguang [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

2012-08-15

Highlights: Black-Right-Pointing-Pointer Ciprofloxacin in water was degraded by heterogeneous catalytic ozonation. Black-Right-Pointing-Pointer MnOx were supported on MWCNTs to serve as catalyst for ozonation. Black-Right-Pointing-Pointer MnOx/MWCNT exhibited highly catalytic activity on ozonation of ciprofloxacin in water. Black-Right-Pointing-Pointer MnOx/MWCNT resulted in effective antibacterial activity inhibition on ciprofloxacin. Black-Right-Pointing-Pointer MnOx/MWCNT promoted the generation of hydroxyl radicals. - Abstract: Carbon nanotube-supported manganese oxides (MnOx/MWCNT) were used as catalysts to assist ozone in degrading ciprofloxacin in water. Manganese oxides were successfully loaded on multi-walled carbon nanotube surfaces by simply impregnating the carbon nanotube with permanganate solution. The catalytic activities of MnOx/MWCNT in ciprofloxacin ozonation, including degradation, mineralization effectiveness, and antibacterial activity change, were investigated. The presence of MnOx/MWCNT significantly elevated the degradation and mineralization efficiency of ozone on ciprofloxacin. The microbiological assay with a reference Escherichia coli strain indicated that ozonation with MnOx/MWCNT results in more effective antibacterial activity inhibition of ciprofloxacin than that in ozonation alone. The effects of catalyst dose, initial ciprofloxacin concentration, and initial pH conditions on ciprofloxacin ozonation with MnOx/MWCNT were surveyed. Electron spin resonance trapping was applied to assess the role of MnOx/MWCNT in generating hydroxyl radicals (HO{center_dot}) during ozonation. Stronger 5,5-dimethyl-1-pyrroline-N-oxide-OH signals were observed in the ozonation with MnOx/MWCNT compared with those in ozonation alone, indicating that MnOx/MWCNT promoted the generation of hydroxyl radicals. The degradation of ciprofloxacin was studied in drinking water and wastewater process samples to gauge the potential effects of water background matrix on

Earth's ozone layer

International Nuclear Information System (INIS)

Lasa, J.

1991-01-01

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

Urban Summertime Ozone of China: Peak Ozone Hour and Nighttime Mixing

Science.gov (United States)

Qu, H.; Wang, Y.; Zhang, R.

2017-12-01

We investigate the observed diurnal cycle of summertime ozone in the cities of China using a regional chemical transport model. The simulated daytime ozone is in general agreement with the observations. Model simulations suggest that the ozone peak time and peak concentration are a function of NOx (NO + NO2) and volatile organic compound (VOC) emissions. The differences between simulated and observed ozone peak time and peak concentration in some regions can be applied to understand biases in the emission inventories. For example, the VOCs emissions are underestimated over the Pearl River Delta (PRD) region, and either NOx emissions are underestimated or VOC emissions are overestimated over the Yangtze River Delta (YRD) regions. In contrast to the general good daytime ozone simulations, the simulated nighttime ozone has a large low bias of up to 40 ppbv. Nighttime ozone in urban areas is sensitive to the nocturnal boundary-layer mixing, and enhanced nighttime mixing (from the surface to 200-500 m) is necessary for the model to reproduce the observed level of ozone.

Total ozone changes in the 1987 Antarctic ozone hole

Science.gov (United States)

Krueger, Arlin J.; Schoeberl, Mark R.; Doiron, Scott D.; Sechrist, Frank; Galimore, Reginald

1988-01-01

The development of the Antarctic ozone minimum was observed in 1987 with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) instrument. In the first half of August the near-polar (60 and 70 deg S) ozone levels were similar to those of recent years. By September, however, the ozone at 70 and 80 deg S was clearly lower than any previous year including 1985, the prior record low year. The levels continued to decrease throughout September until October 5 when a new record low of 109 DU was established at a point near the South Pole. This value is 29 DU less than the lowest observed in 1985 and 48 DU less than the 1986 low. The zonal mean total ozone at 60 deg S remained constant throughout the time of ozone hole formation. The ozone decline was punctuated by local minima formed away from the polar night boundary at about 75 deg S. The first of these, on August 15 to 17, formed just east of the Palmer Peninsula and appears to be a mountain wave. The second major minimum formed on September 5 to 7 again downwind of the Palmer Peninsula. This event was larger in scale than the August minimum and initiated the decline of ozone across the polar region. The 1987 ozone hole was nearly circular and pole centered for its entire life. In previous years the hole was perturbed by intrusions of the circumpolar maximum into the polar regions, thus causing the hole to be elliptical. The 1987 hole also remained in place until the end of November, a few days longer than in 1985, and this persistence resulted in the latest time for recovery to normal values yet observed.

Ozonation control and effects of ozone on water quality in recirculating aquaculture systems

DEFF Research Database (Denmark)

Spiliotopoulou, Aikaterini; Rojas-Tirado, Paula Andrea; Chetri, Ravi K.

2018-01-01

To address the undesired effect of chemotherapeutants in aquaculture, ozone has been suggested as an alternative to improve water quality. To ensure safe and robust treatment, it is vital to define the ozone demand and ozone kinetics of the specific water matrix to avoid ozone overdose. Different...... ozone dosages were applied to water in freshwater recirculating aquaculture systems (RAS). Experiments were performed to investigate ozone kinetics and demand, and to evaluate the effects on the water quality, particularly in relation to fluorescent organic matter. This study aimed at predicting...... a suitable ozone dosage for water treatment based on daily ozone demand via laboratory studies. These ozone dosages will be eventually applied and maintained at these levels in pilot-scale RAS to verify predictions. Selected water quality parameters were measured, including natural fluorescence and organic...

Elevation of susceptibility to ozone-induced acute tracheobronchial injury in transgenic mice deficient in Clara cell secretory protein

International Nuclear Information System (INIS)

Plopper, C.G.; Mango, G.W.; Hatch, G.E.; Wong, V.J.; Toskala, E.; Reynolds, S.D.; Tarkington, B.K.; Stripp, B.R.

2006-01-01

Increases in Clara cell abundance or cellular expression of Clara cell secretory protein (CCSP) may cause increased tolerance of the lung to acute oxidant injury by repeated exposure to ozone (O 3 ). This study defines how disruption of the gene for CCSP synthesis affects the susceptibility of tracheobronchial epithelium to acute oxidant injury. Mice homozygous for a null allele of the CCSP gene (CCSP-/-) and wild type (CCSP+/+) littermates were exposed to ozone (0.2 ppm, 8 h; 1 ppm, 8 h) or filtered air. Injury was evaluated by light and scanning electron microscopy, and the abundance of necrotic, ciliated, and nonciliated cells was estimated by morphometry. Proximal and midlevel intrapulmonary airways and terminal bronchioles were evaluated. There was no difference in airway epithelial composition between CCSP+/+ and CCSP-/- mice exposed to filtered air, and exposure to 0.2 ppm ozone caused little injury to the epithelium of both CCSP+/+ and CCSP-/- mice. After exposure to 1.0 ppm ozone, CCSP-/- mice suffered from a greater degree of epithelial injury throughout the airways compared to CCSP+/+ mice. CCSP-/- mice had both ciliated and nonciliated cell injury. Furthermore, lack of CCSP was associated with a shift in airway injury to include proximal airway generations. Therefore, we conclude that CCSP modulates the susceptibility of the epithelium to oxidant-induced injury. Whether this is due to the presence of CCSP on the acellular lining layer surface and/or its intracellular distribution in the secretory cell population needs to be defined

Ozone modeling

International Nuclear Information System (INIS)

McIllvaine, C.M.

1994-01-01

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

Vegetation-mediated Climate Impacts on Historical and Future Ozone Air Quality

Science.gov (United States)

Tai, A. P. K.; Fu, Y.; Mickley, L. J.; Heald, C. L.; Wu, S.

2014-12-01

Changes in climate, natural vegetation and human land use are expected to significantly influence air quality in the coming century. These changes and their interactions have important ramifications for the effectiveness of air pollution control strategies. In a series of studies, we use a one-way coupled modeling framework (GEOS-Chem driven by different combinations of historical and future meteorological, land cover and emission data) to investigate the effects of climate-vegetation changes on global and East Asian ozone air quality from 30 years ago to 40 years into the future. We find that future climate and climate-driven vegetation changes combine to increase summertime ozone by 2-6 ppbv in populous regions of the US, Europe, East Asia and South Asia by year 2050, but including the interaction between CO2 and biogenic isoprene emission reduces the climate impacts by more than half. Land use change such as cropland expansion has the potential to either mostly offset the climate-driven ozone increases (e.g., in the US and Europe), or greatly increase ozone (e.g., in Southeast Asia). The projected climate-vegetation effects in East Asia are particularly uncertain, reflecting a less understood ozone production regime. We thus further study how East Asian ozone air quality has evolved since the early 1980s in response to climate, vegetation and emission changes to shed light on its likely future course. We find that warming alone has led to a substantial increase in summertime ozone in populous regions by 1-4 ppbv. Despite significant cropland expansion and urbanization, increased summertime leafiness of vegetation in response to warming and CO2 fertilization has reduced ozone by 1-2 ppbv, driven by enhanced ozone deposition dominating over elevated biogenic emission and partially offsetting the warming effect. The historical role of CO2-isoprene interaction in East Asia, however, remains highly uncertain. Our findings demonstrate the important roles of land cover

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

Directory of Open Access Journals (Sweden)

C. Roy

2017-01-01

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

Ozone flux over a Norway spruce forest and correlation with net ecosystem production

International Nuclear Information System (INIS)

Zapletal, Milos; Cudlin, Pavel; Chroust, Petr; Urban, Otmar; Pokorny, Radek; Edwards-Jonasova, Magda; Czerny, Radek; Janous, Dalibor; Taufarova, Klara; Vecera, Zbynek; Mikuska, Pavel; Paoletti, Elena

2011-01-01

Daily ozone deposition flux to a Norway spruce forest in Czech Republic was measured using the gradient method in July and August 2008. Results were in good agreement with a deposition flux model. The mean daily stomatal uptake of ozone was around 47% of total deposition. Average deposition velocity was 0.39 cm s -1 and 0.36 cm s -1 by the gradient method and the deposition model, respectively. Measured and modelled non-stomatal uptake was around 0.2 cm s -1 . In addition, net ecosystem production (NEP) was measured by using Eddy Covariance and correlations with O 3 concentrations at 15 m a.g.l., total deposition and stomatal uptake were tested. Total deposition and stomatal uptake of ozone significantly decreased NEP, especially by high intensities of solar radiation. - Highlights: → We estimate ozone deposition flux to a Norway spruce forest using the gradient method and model. → The mean stomatal uptake of ozone is approximately 47% of the total deposition. → We measure net ecosystem production (NEP) using Eddy Covariance. → We test whether elevated total deposition and stomatal uptake of O 3 imply a reduction of NEP. → Deposition and stomatal uptake of O 3 decrease NEP, especially by high intensities of solar radiation. - Net ecosystem production of a Norway spruce forest decreases with increasing deposition and stomatal uptake of ozone.

The response of some common Egyptian plants to ozone and their use as biomonitors

International Nuclear Information System (INIS)

El-Khatib, A.A.

2003-01-01

Growth and physiological response of plants was shown to be an effective tool for O 3 -biomonitoring. - Relative sensitivity of five common Egyptian plant species namely, Senecio vulgaris, Malva parviflora, Sonchus oleraceus, Medicago sativa and Melilotus indicus to elevated levels of ozone has been studied. The plants were exposed to charcoal filtered air (CFA) and different levels of O 3 (50 and 100 ppb) for 5 h per day. The studied parameters were recorded for five consecutive days after fumigation. The foliar injury varied significantly among species in a dose-dependent manner. Severe injury symptoms were recorded on the leaves of M. sativa. With the exception of M. parviflora, all species exhibited significant increases in the percentage reduction of the above-ground dry weight as a result of reductions in both leaf and stem dry weights. M. sativa showed a marked reduction in its relative growth rate at elevated levels of O 3 . The extent of chlorophyll a destruction was higher in both M. sativa and S. oleraceus than in the other species tested. No differences in the sensitivity of chlorophylls a+b and carotenoids to ozone levels were recorded in this work. Percentage reduction of ascorbic acid was higher in M. sativa and S. oleraceus, compared with the other species studied. With respect to relative percentages of proline, there was a significant difference in the responses of plants to ozone. According to the ozone resistance (R%), measured as relative growth rate, the test species were arranged in the descending order: M. parviflora>M. Indicus>S. Vulgaris>S. Oleraceus>M. sativa. In M. sativa, both determinant and correlation coefficients are well reflected in the relationship between its physiological response, its performance and ozone levels, supporting its recommendation as a candidate for biomonitoring in Egypt

The response of some common Egyptian plants to ozone and their use as biomonitors

Energy Technology Data Exchange (ETDEWEB)

El-Khatib, A A

2003-08-01

Growth and physiological response of plants was shown to be an effective tool for O{sub 3}-biomonitoring. - Relative sensitivity of five common Egyptian plant species namely, Senecio vulgaris, Malva parviflora, Sonchus oleraceus, Medicago sativa and Melilotus indicus to elevated levels of ozone has been studied. The plants were exposed to charcoal filtered air (CFA) and different levels of O{sub 3} (50 and 100 ppb) for 5 h per day. The studied parameters were recorded for five consecutive days after fumigation. The foliar injury varied significantly among species in a dose-dependent manner. Severe injury symptoms were recorded on the leaves of M. sativa. With the exception of M. parviflora, all species exhibited significant increases in the percentage reduction of the above-ground dry weight as a result of reductions in both leaf and stem dry weights. M. sativa showed a marked reduction in its relative growth rate at elevated levels of O{sub 3}. The extent of chlorophyll a destruction was higher in both M. sativa and S. oleraceus than in the other species tested. No differences in the sensitivity of chlorophylls a+b and carotenoids to ozone levels were recorded in this work. Percentage reduction of ascorbic acid was higher in M. sativa and S. oleraceus, compared with the other species studied. With respect to relative percentages of proline, there was a significant difference in the responses of plants to ozone. According to the ozone resistance (R%), measured as relative growth rate, the test species were arranged in the descending order: M. parviflora>M. Indicus>S. Vulgaris>S. Oleraceus>M. sativa. In M. sativa, both determinant and correlation coefficients are well reflected in the relationship between its physiological response, its performance and ozone levels, supporting its recommendation as a candidate for biomonitoring in Egypt.

Ozone Induced Premature Mortality and Crop Yield Loss in China

Science.gov (United States)

Lin, Y.; Jiang, F.; Wang, H.

2017-12-01

Exposure to ambient ozone is a major risk factor for health impacts such as chronic obstructive pulmonary disease (COPD) and cause damage to plant and agricultural crops. But these impacts were usually evaluated separately in earlier studies. We apply Community Multi-scale Air Quality model to simulate the ambient O3 concentration at a resolution of 36 km×36 km across China. Then, we follow Global Burden of Diseases approach and AOT40 (i.e., above a threshold of 40 ppb) metric to estimate the premature mortalities and yield losses of major grain crops (i.e., winter wheat, rice and corn) across China due to surface ozone exposure, respectively. Our results show that ozone exposure leads to nearly 67,700 premature mortalities and 145 billion USD losses in 2014. The ozone induced yield losses of all crop production totaled 78 (49.9-112.6)million metric tons, worth 5.3 (3.4-7.6)billion USD, in China. The relative yield losses ranged from 8.5-14% for winter wheat, 3.9-15% for rice, and 2.2-5.5% for maize. We can see that the top four health affected provinces (Sichuan, Henan, Shandong, Jiangsu) are also ranking on the winter wheat and rice crop yield loss. Our results provide further evidence that surface ozone pollution is becoming urgent air pollution in China, and have important policy implications for China to alleviate the impacts of air pollution.

Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

Energy Technology Data Exchange (ETDEWEB)

Broennimann, S.; Siegrist, F.C.; Eugster, W.; Cattin, R.; Sidle, C.; Wanner, H. [Inst. of Geography, Univ. of Bern (Switzerland); Hirschberg, M.M. [Lehrstuhl fuer Bioklimatologie und Immissionsforschung, TU Muenchen, Freising-Weihenstephan (Germany); Schneiter, D. [MeteoSwiss, Station Aerologique, Payerne (Switzerland); Perego, S. [IBM Switzerland, Zuerich (Switzerland)

2001-04-01

The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999). Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau. (orig.)

The influence of European pollution on ozone in the Near East and northern Africa

Directory of Open Access Journals (Sweden)

B. N. Duncan

2008-04-01

Full Text Available We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50–150 additional violations per year (i.e. above those that would occur without European pollution of the European health standard for ozone (8-h average >120 μg/m³ or ~60 ppbv in northern Africa and the Near East. We estimate that European ozone pollution is responsible for 50 000 premature mortalities globally each year, of which the majority occurs outside of Europe itself, including 37% (19 000 in northern Africa and the Near East. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions.

The Influence of European Pollution on Ozone in the Near East and Northern Africa

Science.gov (United States)

Duncan, B. N.; West, J. J.; Yoshida, Y.; Fiore, A. M.; Ziemke, J. R.

2008-01-01

We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50-150 additional violations per year (i.e. above those that would occur without European pollution) of the European health standard for ozone (8-h average greater than 120 micrograms per cubic meters or approximately 60 ppbv) in northern Africa and the Near East. We estimate that European ozone pollution is responsible for 50 000 premature mortalities globally each year, of which the majority occurs outside of Europe itself, including 37% (19 000) in northern Africa and the Near East. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions.

Ozone modeling

Energy Technology Data Exchange (ETDEWEB)

McIllvaine, C M

1994-07-01

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

The Antarctic ozone hole

International Nuclear Information System (INIS)

Jones, Anna E

2008-01-01

Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For the historical perspective, the events leading up to the discovery of the 'hole' are presented, as well as the response from the international community and the measures taken to protect the ozone layer now and into the future

Evidence for a continuous decline in lower stratospheric ozone offsetting ozone layer recovery

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Ball, William T.; Alsing, Justin; Mortlock, Daniel J.; Staehelin, Johannes; Haigh, Joanna D.; Peter, Thomas; Tummon, Fiona; Stübi, Rene; Stenke, Andrea; Anderson, John; Bourassa, Adam; Davis, Sean M.; Degenstein, Doug; Frith, Stacey; Froidevaux, Lucien; Roth, Chris; Sofieva, Viktoria; Wang, Ray; Wild, Jeannette; Yu, Pengfei; Ziemke, Jerald R.; Rozanov, Eugene V.

2018-02-01

Ozone forms in the Earth's atmosphere from the photodissociation of molecular oxygen, primarily in the tropical stratosphere. It is then transported to the extratropics by the Brewer-Dobson circulation (BDC), forming a protective ozone layer around the globe. Human emissions of halogen-containing ozone-depleting substances (hODSs) led to a decline in stratospheric ozone until they were banned by the Montreal Protocol, and since 1998 ozone in the upper stratosphere is rising again, likely the recovery from halogen-induced losses. Total column measurements of ozone between the Earth's surface and the top of the atmosphere indicate that the ozone layer has stopped declining across the globe, but no clear increase has been observed at latitudes between 60° S and 60° N outside the polar regions (60-90°). Here we report evidence from multiple satellite measurements that ozone in the lower stratosphere between 60° S and 60° N has indeed continued to decline since 1998. We find that, even though upper stratospheric ozone is recovering, the continuing downward trend in the lower stratosphere prevails, resulting in a downward trend in stratospheric column ozone between 60° S and 60° N. We find that total column ozone between 60° S and 60° N appears not to have decreased only because of increases in tropospheric column ozone that compensate for the stratospheric decreases. The reasons for the continued reduction of lower stratospheric ozone are not clear; models do not reproduce these trends, and thus the causes now urgently need to be established.

Evidence for a Continuous Decline in Lower Stratospheric Ozone Offsetting Ozone Layer Recovery

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Ball, William T.; Alsing, Justin; Mortlock, Daniel J.; Staehelin, Johannes; Haigh, Joanna D.; Peter, Thomas; Tummon, Fiona; Stuebi, Rene; Stenke, Andrea; Anderson, John;

Ozonated Olive Oils and Troubles

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Bulent Uysal

2014-04-01

Full Text Available One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. [J Intercult Ethnopharmacol 2014; 3(2.000: 49-50

Ozone-Induced Nasal Type 2 Immunity in Mice Is Dependent on Innate Lymphoid Cells.

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Kumagai, Kazuyoshi; Lewandowski, Ryan; Jackson-Humbles, Daven N; Li, Ning; Van Dyken, Steven J; Wagner, James G; Harkema, Jack R

2016-06-01

Epidemiological studies suggest that elevated ambient concentrations of ozone are associated with activation of eosinophils in the nasal airways of atopic and nonatopic children. Mice repeatedly exposed to ozone develop eosinophilic rhinitis and type 2 immune responses. In this study, we determined the role of innate lymphoid cells (ILCs) in the pathogenesis of ozone-induced eosinophilic rhinitis by using lymphoid-sufficient C57BL/6 mice, Rag2(-/-) mice that are devoid of T cells and B cells, and Rag2(-/-)Il2rg(-/-) mice that are depleted of all lymphoid cells including ILCs. The animals were exposed to 0 or 0.8 ppm ozone for 9 consecutive weekdays (4 h/d). Mice were killed 24 hours after exposure, and nasal tissues were selected for histopathology and gene expression analysis. ILC-sufficient C57BL/6 and Rag2(-/-) mice exposed to ozone developed marked eosinophilic rhinitis and epithelial remodeling (e.g., epithelial hyperplasia and mucous cell metaplasia). Chitinase-like proteins and alarmins (IL-33, IL-25, and thymic stromal lymphopoietin) were also increased morphometrically in the nasal epithelium of ozone-exposed C57BL/6 and Rag2(-/-) mice. Ozone exposure elicited increased expression of Il4, Il5, Il13, St2, eotaxin, MCP-2, Gob5, Arg1, Fizz1, and Ym2 mRNA in C57BL/6 and Rag2(-/-) mice. In contrast, ozone-exposed ILC-deficient Rag2(-/-)Il2rg(-/-) mice had no nasal lesions or overexpression of Th2- or ILC2-related transcripts. These results indicate that ozone-induced eosinophilic rhinitis, nasal epithelial remodeling, and type 2 immune activation are dependent on ILCs. To the best of our knowledge, this is the first study to demonstrate that ILCs play an important role in the nasal pathology induced by repeated ozone exposure.

SMM mesospheric ozone measurements

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Aikin, A. C.

1990-01-01

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

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

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Tripathi, Ruchika; Agrawal, S B

2012-11-01

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, ω-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. Copyright © 2012 Elsevier Inc. All rights reserved.

Long-term ambient concentrations of total suspended particulates and oxidants as related to incidence of chronic disease in California Seventh-Day Adventists

Energy Technology Data Exchange (ETDEWEB)

Abbey, D.E.; Mills, P.K.; Petersen, F.F.; Beeson, W.L. (Loma Linda Univ. School of Medicine, CA (United States))

1991-08-01

Cancer incidence and mortality in a cohort of 6000 nonsmoking California Seventh-Day Adventists were monitored for a 6-year period, and relationships with long-term cumulative air pollution were observed. Total suspended particulates (TSP) and ozone were measured in terms of numbers of hours in excess of several threshold levels corresponding to national standards as well as mean concentration. For all malignant neoplasms among females, risk increased with increasing exceedance frequencies of all thresholds of TSP except the lowest one, and those increased risks were highly statistically significant. For respiratory cancers, increased risk was associated with only one threshold of ozone, and this result was of borderline significance. Respiratory disease symptoms were assessed in 1977 and again in 1987 using the National Heart, Lung and Blood Institute respiratory symptoms questionnaire on a subcohort of 3914 individuals. Multivariate analyses which adjusted for past and passive smoking and occupational exposures indicated statistically significantly elevated relative risks ranging up to 1.7 for incidence of asthma, definite symptoms of airway obstructive disease, and chronic bronchitis with TSP in excess of all thresholds except the lowest one but not for any thresholds of ozone. A trend association was noted between the threshold of 10 pphm ozone and incidence of asthma. These results are presented within the context of standards setting for these constituents of air pollution.

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-06-01

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

Spatial clustering and meteorological drivers of summer ozone in Europe

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Carro-Calvo, Leopoldo; Ordóñez, Carlos; García-Herrera, Ricardo; Schnell, Jordan L.

2017-04-01

We present a regionalization of summer near-surface ozone (O3) in Europe. For this purpose we apply a K-means algorithm on a gridded MDA8 O3 (maximum daily average 8-h ozone) dataset covering a European domain [15° W - 30° E, 35°-70° N] at 1° x 1° horizontal resolution for the 1998-2012 period. This dataset was compiled by merging observations from the European Monitoring and Evaluation Programme (EMEP) and the European Environment Agency's air quality database (AirBase). The K-means method allows identifying sets of different regions where the O3 concentrations present coherent spatiotemporal patterns and are thus expected to be driven by similar meteorological factors. After some testing, 9 regions were selected: the British Isles, North-Central Europe, Northern Scandinavia, the Baltic countries, the Iberian Peninsula, Western Europe, South-Central Europe, Eastern Europe and the Balkans. For each region we examine the synoptic situations associated with elevated ozone extremes (days exceeding the 95th percentile of the summer MDA8 O3 distribution). Our analyses reveal that there are basically two different kinds of regions in Europe: (a) those in the centre and south of the continent where ozone extremes are associated with elevated temperature within the same region and (b) those in northern Europe where ozone extremes are driven by southerly advection of air masses from warmer, more polluted areas. Even when the observed patterns were initially identified only for days registering high O3 extremes, all summer days can be projected on such patterns to identify the main modes of meteorological variability of O3. We have found that such modes are partly responsible for the day-to-day variability in the O3 concentrations and can explain a relatively large fraction (from 44 to 88 %, depending on the region) of the interannual variability of summer mean MDA8 O3 during the period of analysis. On the other hand, some major teleconnection patterns have been tested

Vertical Distribution of Ozone and Nitric Acid Vapor on the Mammoth Mountain, Eastern Sierra Nevada, California

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Andrzej Bytnerowicz

2002-01-01

Full Text Available In August and September 1999 and 2000, concentrations of ozone (O3 and nitric acid vapor (HNO3 were monitored at an elevation gradient (2184–3325 m on the Mammoth Mountain, eastern Sierra Nevada, California. Passive samplers were used for monitoring exposure to tropospheric O3 and HNO3 vapor. The 2-week average O3 concentrations ranged between 45 and 72 ppb, while HNO3 concentrations ranged between 0.06 and 0.52 μg/m3. Similar ranges of O3 and HNO3 were determined for 2 years of the study. No clear effects of elevation on concentrations of the two pollutants were detected. Concentrations of HNO3 were low and at the background levels expected for the eastern Sierra Nevada, while the measured concentrations of O3 were elevated. High concentrations of ozone in the study area were confirmed with an active UV absorption O3 monitor placed at the Mammoth Mountain Peak (September 5–14, 2000, average 24-h concentration of 56 ppb.

Clinical predictors and hemodynamic consequences of elevated peripheral chemosensitivity in optimally treated men with chronic systolic heart failure.

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Niewinski, Piotr; Engelman, Zoar J; Fudim, Marat; Tubek, Stanislaw; Paleczny, Bartlomiej; Jankowska, Ewa A; Banasiak, Waldemar; Sobotka, Paul A; Ponikowski, Piotr

2013-06-01

Augmented peripheral chemoreflex response is an important mechanism in the pathophysiology of chronic heart failure (CHF). This study characterizes prevalence and clinical predictors of this phenomenon in optimally managed male CHF patients, and seeks to describe the hemodynamic consequences of chemoreceptor hypersensitivity. Thirty-four optimally managed CHF patients and 16 control subjects were prospectively studied. Hypoxic ventilatory response (HVR)-a measure of peripheral chemosensitivity-was calculated with the use of short nitrogen gas administrations. Systolic blood pressure (SBP) and heart rate (HR) following transient hypoxic challenges were recorded with a Nexfin monitor. Hemodynamic responses to hypoxia were expressed by the linear slopes between oxygen saturation (%) and SBP (mm Hg) or HR (beats/min). Elevated HVR was present in 15 (44%) of the CHF patients. Patients with elevated HVR exhibited higher levels of N-terminal pro-B-type natriuretic peptide, lower left ventricular ejection fraction, and higher prevalence of atrial fibrillation. CHF patients with elevated HVR had significantly greater SBP and HR responses to hypoxia than CHF patients with normal HVR. Despite comprehensive pharmacotherapy, elevated HVR is prevalent in CHF patients, related to severity of the disease and associated with augmented hemodynamic responses to hypoxia. CHF patients with elevated HVR may be prone to unfavorable hemodynamic changes. Copyright © 2013 Elsevier Inc. All rights reserved.

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

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

2016-06-01

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

Associations between ozone and morbidity using the Spatial Synoptic Classification system

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Arora Gurmeet

2011-05-01

Full Text Available Abstract Background Synoptic circulation patterns (large-scale tropospheric motion systems affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses on the association between ozone and hospital admissions for asthma and myocardial infarction (MI among adults in North Carolina. Methods Daily surface meteorology data (including precipitation, wind speed, and dew point for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS, which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions. Results Ozone was associated with asthma under dry tropical (1- to 5-day lags, transitional (3- and 4-day lags, and extreme moist tropical (0-day lag air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag air masses. Conclusions Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain

Ozone Antimicrobial Efficacy

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Ozone is a potent germicide that has been used extensively for water purification. In Europe, 90 percent of the municipal water systems are treated with ozone, and in France, ozone has been used to treat drinking water since 1903. However, there is limited information on the bioc...

Ozone-induced airway hyperresponsiveness in patients with asthma: role of neutrophil-derived serine proteinases.

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Hiltermann, T J; Peters, E A; Alberts, B; Kwikkers, K; Borggreven, P A; Hiemstra, P S; Dijkman, J H; van Bree, L A; Stolk, J

1998-04-01

Proteinase inhibitors may be of potential therapeutic value in the treatment of respiratory diseases such as chronic obstructive pulmonary disease (COPD) or asthma. Our aim was to study the role of neutrophils, and neutrophil-derived serine proteinases in an acute model in patients with asthma. Exposure to ozone induces an acute neutrophilic inflammatory reaction accompanied by an increase in airway hyperresponsiveness. It is thought that these two effects of ozone are linked, and that neutrophil-derived serine proteinases (i.e. elastase) may play a role in the ozone-induced airway hyperresponsiveness. Therefore, we examined the effect of recombinant antileukoprotease (rALP), one of the major serine proteinase inhibitors in the lung, on ozone-induced changes in airway hyperresponsiveness in this model. We observed that 16 h after exposure to ozone, airway hyperresponsiveness to methacholine was increased both following placebo and rALP treatment. There was no significant difference between placebo and rALP treatment (change in area under the dose-response curve to methacholine: 117.3+/-59.0 vs 193.6+/-59.6 % fall x DD; p=.12). Moreover, the immediate decrease in FEV1 after ozone exposure was not significantly different between the two groups (placebo: -29.6+/-6.7%; rALP: -20.9+/-3.8%; p=.11). In addition, no significant differences were observed in plasma levels of fibrinogen degradation products generated by neutrophil serine proteinases before and after exposure to ozone. We conclude that neutrophil-derived serine proteinases are not important mediators for ozone-induced hyperresponsiveness.

Evaluating ozone air pollution effects on pines in the western United States

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Paul R. Miller; Kenneth W. Stolte; Daniel M. Duriscoe; John Pronos

1996-01-01

Historical and technical background is provided about ozone air pollution effects on ponderosa (Pinus ponderosa Dougl. ex Laws) and Jeffrey (P. jeffreyi Grev. and Balf.) pines in forests of the western United States. The principal aim is to document the development of field survey methods to be applied to assessment of chronic...

Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats

International Nuclear Information System (INIS)

Gultekin, Fatma Ayca; Bakkal, Bekir Hakan; Guven, Berrak; Tasdoven, Ilhan; Bektas, Sibel; Can, Murat; Comert, Mustafa

2013-01-01

Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-α levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity. (author)

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

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R.M. Cox

2001-01-01

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

Ambient Ozone Pollution and Daily Mortality: A Nationwide Study in 272 Chinese Cities.

Science.gov (United States)

Yin, Peng; Chen, Renjie; Wang, Lijun; Meng, Xia; Liu, Cong; Niu, Yue; Lin, Zhijing; Liu, Yunning; Liu, Jiangmei; Qi, Jinlei; You, Jinling; Zhou, Maigeng; Kan, Haidong

2017-11-21

Few large multicity studies have been conducted in developing countries to address the acute health effects of atmospheric ozone pollution. We explored the associations between ozone and daily cause-specific mortality in China. We performed a nationwide time-series analysis in 272 representative Chinese cities between 2013 and 2015. We used distributed lag models and over-dispersed generalized linear models to estimate the cumulative effects of ozone (lagged over 0-3 d) on mortality in each city, and we used hierarchical Bayesian models to combine the city-specific estimates. Regional, seasonal, and demographic heterogeneity were evaluated by meta-regression. At the national-average level, a 10-μg/m 3 increase in 8-h maximum ozone concentration was associated with 0.24% [95% posterior interval (PI): 0.13%, 0.35%], 0.27% (95% PI: 0.10%, 0.44%), 0.60% (95% PI: 0.08%, 1.11%), 0.24% (95% PI: 0.02%, 0.46%), and 0.29% (95% PI: 0.07%, 0.50%) higher daily mortality from all nonaccidental causes, cardiovascular diseases, hypertension, coronary diseases, and stroke, respectively. Associations between ozone and daily mortality due to respiratory and chronic obstructive pulmonary disease specifically were positive but imprecise and nonsignificant. There were no statistically significant differences in associations between ozone and nonaccidental mortality according to region, season, age, sex, or educational attainment. Our findings provide robust evidence of higher nonaccidental and cardiovascular mortality in association with short-term exposure to ambient ozone in China. https://doi.org/10.1289/EHP1849.

An Elevated Reservoir of Air Pollutants over the Mid-Atlantic States During the 2011 DISCOVER-AQ Campaign: Airborne Measurements and Numerical Simulations

Science.gov (United States)

He, Hao; Loughner, Christopher P.; Stehr, Jeffrey W.; Arkinson, Heather L.; Brent, Lacey C.; Follette-Cook, Melanie B.; Tzortziou, Maria A.; Pickering, Kenneth E.; Thompson, Anne M.; Martins, Douglas K.;

Anxiogenic-like effect of acute and chronic fluoxetine on rats tested on the elevated plus-maze

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M.T.A. Silva

1999-03-01

Full Text Available The selective serotonin reuptake inhibitor fluoxetine (FLX is widely prescribed for depression and anxiety-related disorders. On the other hand, enhanced serotonergic transmission is known to be classically related to anxiety. In this study, the effects of acute (5.0 mg/kg and chronic (5.0 mg/kg, 22 days FLX were investigated in both food-deprived and non-deprived rats tested in the elevated plus-maze. Significant main effects of the three factors (drug, food condition and administration regimen were observed, but no interaction between them. The administration of either acute or chronic FLX resulted in an anxiogenic effect, as detected by a significant reduction in the percentage of time spent in the open arms and in the percentage of open arm entries. Food deprivation yielded an anxiolytic-like profile, probably related to changes in locomotor activity. The administration regimen resulted in an anxiolytic profile in chronically treated rats, as would be expected after 22 days of regular handling. The anxiogenic action of acute FLX is consistent with both its neurochemical and clinical profile. The discrepancy between the anxiogenic profile of chronic FLX and its therapeutic uses is discussed in terms of possible differences between the type of anxiety that is measured in the plus-maze and the types of human anxiety that are alleviated by fluoxetine.

Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

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S. Brönnimann

2001-04-01

Full Text Available The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999. Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau.Key words. Atmospheric composition and structure (pollution – urban and regional; troposphere – composition and  chemistry – Meteorology and atmospheric dynamics (mesoscale meteorology

Merged SAGE II, Ozone_cci and OMPS ozone profile dataset and evaluation of ozone trends in the stratosphere

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V. F. Sofieva

2017-10-01

Full Text Available In this paper, we present a merged dataset of ozone profiles from several satellite instruments: SAGE II on ERBS, GOMOS, SCIAMACHY and MIPAS on Envisat, OSIRIS on Odin, ACE-FTS on SCISAT, and OMPS on Suomi-NPP. The merged dataset is created in the framework of the European Space Agency Climate Change Initiative (Ozone_cci with the aim of analyzing stratospheric ozone trends. For the merged dataset, we used the latest versions of the original ozone datasets. The datasets from the individual instruments have been extensively validated and intercompared; only those datasets which are in good agreement, and do not exhibit significant drifts with respect to collocated ground-based observations and with respect to each other, are used for merging. The long-term SAGE–CCI–OMPS dataset is created by computation and merging of deseasonalized anomalies from individual instruments. The merged SAGE–CCI–OMPS dataset consists of deseasonalized anomalies of ozone in 10° latitude bands from 90° S to 90° N and from 10 to 50 km in steps of 1 km covering the period from October 1984 to July 2016. This newly created dataset is used for evaluating ozone trends in the stratosphere through multiple linear regression. Negative ozone trends in the upper stratosphere are observed before 1997 and positive trends are found after 1997. The upper stratospheric trends are statistically significant at midlatitudes and indicate ozone recovery, as expected from the decrease of stratospheric halogens that started in the middle of the 1990s and stratospheric cooling.

Tropospheric Ozone from the TOMS TDOT (TOMS-Direct-Ozone-in-Troposphere) Technique During SAFARI-2000

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Stone, J. B.; Thompson, A. M.; Frolov, A. D.; Hudson, R. D.; Bhartia, P. K. (Technical Monitor)

2002-01-01

There are a number of published residual-type methods for deriving tropospheric ozone from TOMS (Total Ozone Mapping Spectrometer). The basic concept of these methods is that within a zone of constant stratospheric ozone, the tropospheric ozone column can be computed by subtracting stratospheric ozone from the TOMS Level 2 total ozone column, We used the modified-residual method for retrieving tropospheric ozone during SAFARI-2000 and found disagreements with in-situ ozone data over Africa in September 2000. Using the newly developed TDOT (TOMS-Direct-Ozone-in-Troposphere) method that uses TOMS radiances and a modified lookup table based on actual profiles during high ozone pollution periods, new maps were prepared and found to compare better to soundings over Lusaka, Zambia (15.5 S, 28 E), Nairobi and several African cities where MOZAIC aircraft operated in September 2000. The TDOT technique and comparisons are described in detail.

A Review of Atmospheric Ozone and Current Thinking on the Antarctic Ozone Hole.

Science.gov (United States)

1987-01-01

UNIVERSITY OF CALIFORNIA 0 A Review of Atmospheric ozone and Current Thinking on the Antartic Ozone Hole A thesis submitted in partial satisfaction of the...4. TI TLE (Pit 5,1tlfie) S. TYPE OF REPORT & PFRIOO COVERED A Review of Atmospheric Ozone and Current THESIS/DA/;J.At1AAU00 Thinking on the Antartic ...THESIS A Review of Atmospheric Ozone and Current Thinking on the Antartic Ozone Hole by Randolph Antoine Fix Master of Science in Atmospheric Science

Ozone depletion calculations

International Nuclear Information System (INIS)

Luther, F.M.; Chang, J.S.; Wuebbles, D.J.; Penner, J.E.

1992-01-01

Models of stratospheric chemistry have been primarily directed toward an understanding of the behavior of stratospheric ozone. Initially this interest reflected the diagnostic role of ozone in the understanding of atmospheric transport processes. More recently, interest in stratospheric ozone has arisen from concern that human activities might affect the amount of stratospheric ozone, thereby affecting the ultraviolet radiation reaching the earth's surface and perhaps also affecting the climate with various potentially severe consequences for human welfare. This concern has inspired a substantial effort to develop both diagnostic and prognostic models of stratospheric ozone. During the past decade, several chemical agents have been determined to have potentially significant impacts on stratospheric ozone if they are released to the atmosphere in large quantities. These include oxides of nitrogen, oxides of hydrogen, chlorofluorocarbons, bromine compounds, fluorine compounds and carbon dioxide. In order to assess the potential impact of the perturbations caused by these chemicals, mathematical models have been developed to handle the complex coupling between chemical, radiative, and dynamical processes. Basic concepts in stratospheric modeling are reviewed

ATTENUATION OF THE DISRUPTIVE EFFECTS INDUCED BY GAMMA IRRADIATION IN RATS USING OZONATED WATER AND/OR TAURINE

International Nuclear Information System (INIS)

HEIBASHY, M.I.A.; SHAROUD, M.N.M.

2008-01-01

People can be exposed to irradiation either external or internal. The potential for health effects depends in part on the radiation dose delivered, the rate of delivery and where in the body particular radionuclides are concentrated. All radionuclides are partly absorbed from the lung and intestinal tract into the blood stream causing oxidation and free radical formation.In the first experiment, the data showed that the ionizing radiation induced a significant increment in the levels of serum glucose and lipid profile (cholesterol, triglycerides, HDL and LDL) and elevation in the activities of both serum AST and ALT. On the other hand, the ionizing radiation induced a significant decline in the concentrations of serum insulin, total protein, albumin and free T 3 while no remarkable change was occurred on the level of free T 4 . In case of exposing rat to gamma ray, both liver GSH and GPx activities were decreased while the level of liver TBARS was significantly elevated as compared to the corresponding normal control group.In the second experiment, a significant correction was occurred in all previous parameters after the irradiated rats were treated with taurine (500 mg/100g body weight/ day for one month) while the irradiated rats which received ozonated water showed no remarkable changes in the levels of estimated parameters. The best amelioration effect was occurred in the previous parameters in irradiated rats which were treated with both taurine and ozone (ozonated water) for one month.It could be concluded that taurine is considered as a radio-protector agent while ozone (ozonated water) acts as co-radioprotector agent when the irradiated animals are treated by a mixture of those agents

Impact of forest fires, biogenic emissions and high temperatures on the elevated Eastern Mediterranean ozone levels during the hot summer of 2007

Directory of Open Access Journals (Sweden)

Ø. Hodnebrog

2012-09-01

Full Text Available The hot summer of 2007 in southeast Europe has been studied using two regional atmospheric chemistry models; WRF-Chem and EMEP MSC-W. The region was struck by three heat waves and a number of forest fire episodes, greatly affecting air pollution levels. We have focused on ozone and its precursors using state-of-the-art inventories for anthropogenic, biogenic and forest fire emissions. The models have been evaluated against measurement data, and processes leading to ozone formation have been quantified. Heat wave episodes are projected to occur more frequently in a future climate, and therefore this study also makes a contribution to climate change impact research.

The plume from the Greek forest fires in August 2007 is clearly seen in satellite observations of CO and NO₂ columns, showing extreme levels of CO in and downwind of the fires. Model simulations reflect the location and influence of the fires relatively well, but the modelled magnitude of CO in the plume core is too low. Most likely, this is caused by underestimation of CO in the emission inventories, suggesting that the CO/NO_x ratios of fire emissions should be re-assessed. Moreover, higher maximum values are seen in WRF-Chem than in EMEP MSC-W, presumably due to differences in plume rise altitudes as the first model emits a larger fraction of the fire emissions in the lowermost model layer. The model results are also in fairly good agreement with surface ozone measurements.

Biogenic VOC emissions reacting with anthropogenic NO_x emissions are calculated to contribute significantly to the levels of ozone in the region, but the magnitude and geographical distribution depend strongly on the model and biogenic emission module used. During the July and August heat waves, ozone levels increased substantially due to a combination of forest fire emissions and the effect of high temperatures. We found that the largest temperature impact on

[Ozone concentration distribution of urban].

Science.gov (United States)

Yin, Yong-quan; Li, Chang-mei; Ma, Gui-xia; Cui, Zhao-jie

2004-11-01

The increase of ozone concentration in urban is one of the most important research topics on environmental science. With the increase of nitrogen oxides and hydrogen-carbon compounds which are exhausted from cars, the ozone concentration in urban is obviously increased on sunlight, and threat of photochemistry smog will be possible. Therefore, it is very important to monitor and study the ozone concentration distribution in urban. The frequency-distribution, diurnal variation and monthly variation of ozone concentration were studied on the campus of Shandong University during six months monitoring. The influence of solar radiation and weather conditions on ozone concentration were discussed. The frequency of ozone concentration less than 200 microg/m3 is 96.88%. The ozone concentration has an obvious diurnal variation. The ozone concentration in the afternoon is higher than in the morning and in the evening. The maximum appears in June, when it is the strong solar radiation and high air-temperature. The weather conditions also influence the ozone concentration. The ozone concentration in clear day is higher than in rainy and cloudy day.

Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

Science.gov (United States)

Marinov, Daniil; Guerra, Vasco; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine

2013-10-01

A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1-5 Torr and discharge currents ˜40-120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O_3^{*} , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O_3^{*} is strongly coupled with those of atomic oxygen and O2(a 1Δg) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established.

Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

International Nuclear Information System (INIS)

Marinov, Daniil; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine; Guerra, Vasco

2013-01-01

A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1–5 Torr and discharge currents ∼40–120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O 3 * , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O 3 * is strongly coupled with those of atomic oxygen and O 2 (a 1 Δ g ) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established. (paper)

Characteristics of intercontinental transport of tropospheric ozone from Africa to Asia

Science.gov (United States)

Han, Han; Liu, Jane; Yuan, Huiling; Zhuang, Bingliang; Zhu, Ye; Wu, Yue; Yan, Yuhan; Ding, Aijun

2018-03-01

primary transport pathway plays a dominant role in modulating the seasonality. There is more imported African ozone in the Asian upper troposphere in NH spring than in winter. This is likely due to more ozone in the NH African upper troposphere generated from biogenic and lightning NOx emissions in NH spring. The influence of African ozone on Asia appears larger in NH spring than in autumn. This can be attributed to both higher altitudes of the elevated ozone in Africa and stronger subtropical westerlies in NH spring. In NH summer, African ozone hardly reaches Asia because of the blocking by the Saharan High, Arabian High, and Tibetan High on the transport pathway in the middle and upper troposphere, in addition to the northward swing of the subtropical westerlies. The seasonal swings of the intertropical convergence zone (ITCZ) in Africa, coinciding with the geographic variations of the ozone precursor emissions, can further modulate the seasonality of the transport of African ozone, owing to the functions of the ITCZ in enhancing lightning NOx generation and uplifting ozone and ozone precursors to upper layers. The strength of the ITCZ in Africa is also found to be positively correlated with the interannual variation of the transport of African ozone to Asia in NH winter. Ozone from NH Africa makes up over 80 % of the total imported African ozone over Asia in most altitudes and seasons. The interhemispheric transport of ozone from southern hemispheric Africa (SHAF) is most evident in NH winter over the Asian upper troposphere and in NH summer over the Asian lower troposphere. The former case is associated with the primary transport pathway in NH winter, while the latter case is associated with the second transport pathway. The intensities of the ITCZ in Africa and the Somali jet can each explain ˜ 30 % of the interannual variations in the transport of ozone from SHAF to Asia in the two cases.

Highly elevated atmospheric levels of volatile organic compounds in the Uintah Basin, Utah.

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Helmig, D; Thompson, C R; Evans, J; Boylan, P; Hueber, J; Park, J-H

2014-05-06

Oil and natural gas production in the Western United States has grown rapidly in recent years, and with this industrial expansion, growing environmental concerns have arisen regarding impacts on water supplies and air quality. Recent studies have revealed highly enhanced atmospheric levels of volatile organic compounds (VOCs) from primary emissions in regions of heavy oil and gas development and associated rapid photochemical production of ozone during winter. Here, we present surface and vertical profile observations of VOC from the Uintah Basin Winter Ozone Studies conducted in January-February of 2012 and 2013. These measurements identify highly elevated levels of atmospheric alkane hydrocarbons with enhanced rates of C2-C5 nonmethane hydrocarbon (NMHC) mean mole fractions during temperature inversion events in 2013 at 200-300 times above the regional and seasonal background. Elevated atmospheric NMHC mole fractions coincided with build-up of ambient 1-h ozone to levels exceeding 150 ppbv (parts per billion by volume). The total annual mass flux of C2-C7 VOC was estimated at 194 ± 56 × 10(6) kg yr(-1), equivalent to the annual VOC emissions of a fleet of ∼100 million automobiles. Total annual fugitive emission of the aromatic compounds benzene and toluene, considered air toxics, were estimated at 1.6 ± 0.4 × 10(6) and 2.0 ± 0.5 × 10(6) kg yr(-1), respectively. These observations reveal a strong causal link between oil and gas emissions, accumulation of air toxics, and significant production of ozone in the atmospheric surface layer.

Improvement of ozone yield by a multi-discharge type ozonizer using superposition of silent discharge plasma

International Nuclear Information System (INIS)

Song, Hyun-Jig; Chun, Byung-Joon; Lee, Kwang-Sik

2004-01-01

In order to improve ozone generation, we experimentally investigated the silent discharge plasma and ozone generation characteristics of a multi-discharge type ozonizer. Ozone in a multi-discharge type ozonizer is generated by superposition of a silent discharge plasma, which is simultaneously generated in separated discharge spaces. A multi-discharge type ozonizer is composed of three different kinds of superposed silent discharge type ozonizers, depending on the method of applying power to each electrode. We observed that the discharge period of the current pulse for a multi discharge type ozonizer can be longer than that of silent discharge type ozonizer with two electrodes and one gap. Hence, ozone generation is improved up to 17185 ppm and 783 g/kwh in the case of the superposed silent discharge type ozonizer for which an AC high voltages with a 180 .deg. phase difference were applied to the internal electrode and the external electrode, respectively, with the central electrode being grounded.

Profiling secondary metabolites of needles of ozone-fumigated white pine (Pinus strobus) clones by thermally assisted hydrolysis/methylation GC/MS.

Science.gov (United States)

Shadkami, F; Helleur, R J; Cox, R M

2007-07-01

Plant secondary metabolites have an important role in defense responses against herbivores and pathogens, and as a chemical barrier to elevated levels of harmful air pollutants. This study involves the rapid chemical profiling of phenolic and diterpene resin acids in needles of two (ozone-tolerant and ozone-sensitive) white pine (Pinus strobus) clones, fumigated with different ozone levels (control, and daily events peaking at 80 and 200 ppb) for 40 days. The phenolic and resin acids were measured using thermally assisted hydrolysis and methylation (THM) gas chromatography/mass spectrometry. Short-term fumigation affected the levels of two phenolic acids, i.e., 3-hydroxybenzoic and 3,4-dihydroxybenzoic acids, in that both showed a substantial decrease in concentration with increased ozone dose. The decrease in concentration of these THM products may be caused by inhibition of the plant's shikimate biochemical pathway caused by ozone exposure. The combined occurrence of these two ozone-sensitive indicators has a role in biomonitoring of ozone levels and its impact on forest productivity. In addition, chromatographic profile differences in the major diterpene resin acid components were observed between ozone-tolerant and ozone-sensitive clones. The resin acids anticopalic, 3-oxoanticopalic, 3beta-hydroxyanticopalic, and 3,4-cycloanticopalic acids were present in the ozone-sensitive pine; however, only anticopalic acid was present in the ozone-tolerant clone. This phenotypic variation in resin acid composition may be useful in distinguishing populations that are differentially adapted to air pollutants.

Towards the retrieval of tropospheric ozone with the ozone monitoring instrument (OMI)

NARCIS (Netherlands)

Mielonen, T.; De Haan, J.F.; Van Peet, J.C.A.; Eremenko, M.; Veefkind, J.P.

2015-01-01

We have assessed the sensitivity of the operational Ozone Monitoring Instrument (OMI) ozone profile retrieval algorithm to a number of a priori and radiative transfer assumptions. We studied the effect of stray light correction, surface albedo assumptions and a priori ozone profiles on the retrieved

Comparative study of ozonized olive oil and ozonized sunflower oil

OpenAIRE

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

2006-01-01

In this study the ozonized olive and sunflower oils are chemical and microbiologically compared. These oils were introduced into a reactor with bubbling ozone gas in a water bath at room temperature until they were solidified. The peroxide, acidity and iodine values along with antimicrobial activity were determined. Ozonization effects on the fatty acid composition of these oils were analyzed using Gas-Liquid Chromatographic Technique. An increase in peroxidation and acidity values was observ...

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

Science.gov (United States)

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

2017-02-01

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

The Sesquiterpenes(E-ß-Farnesene and (E-α-Bergamotene Quench Ozone but Fail to Protect the Wild Tobacco Nicotiana attenuata from Ozone, UVB, and Drought Stresses.

Directory of Open Access Journals (Sweden)

Evan C Palmer-Young

Full Text Available Among the terpenes, isoprene (C5 and monoterpene hydrocarbons (C10 have been shown to ameliorate abiotic stress in a number of plant species via two proposed mechanisms: membrane stabilization and direct antioxidant effects. Sesquiterpene hydrocarbons (C15 not only share the structural properties thought to lend protective qualities to isoprene and monoterpene hydrocarbons, but also react rapidly with ozone, suggesting that sesquiterpenes may similarly enhance tolerance of abiotic stresses. To test whether sesquiterpenes protect plants against ozone, UVB light, or drought, we used transgenic lines of the wild tobacco Nicotiana attenuata. The transgenic plants expressed a maize terpene synthase gene (ZmTPS10 which produced a blend of (E-ß-farnesene and (E-α-bergamotene, or a point mutant of the same gene (ZmTPS10M which produced (E-ß-farnesene alone,. (E-ß-farnesene exerted a local, external, and transient ozone-quenching effect in ozone-fumigated chambers, but we found no evidence that enhanced sesquiterpene production by the plant inhibited oxidative damage, or maintained photosynthetic function or plant fitness under acute or chronic stress. Although the sesquiterpenes (E-ß-farnesene and (E-α-bergamotene might confer benefits under intermittent heat stress, which was not tested, any roles in relieving abiotic stress may be secondary to their previously demonstrated functions in biotic interactions.

Estonian total ozone climatology

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K. Eerme

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

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

Biomarkers of endothelial dysfunction are elevated and related to prognosis in chronic heart failure patients with diabetes but not in those without diabetes

DEFF Research Database (Denmark)

Kistorp, C.; Chong, A.Y.; Gustafsson, F.

2008-01-01

Biomarkers of endothelial dysfunction, such as soluble E-selectin, and von Willebrand factor (vWf) are elevated in patients with chronic heart failure (CHF). The impact of diabetes mellitus (DM) on these biomarkers, and their relation to prognosis remains unknown....

Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

Directory of Open Access Journals (Sweden)

S. Brönnimann

Full Text Available The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999. Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau.

Key words. Atmospheric composition and structure (pollution – urban and regional; troposphere – composition and  chemistry – Meteorology and atmospheric dynamics (mesoscale meteorology

Seasonal Changes in Tropospheric Ozone Concentrations over South Korea and Its Link to Ozone Precursors

Science.gov (United States)

Jung, H. C.; Moon, B. K.; Wie, J.

2017-12-01

Concentration of tropospheric ozone over South Korea has steadily been on the rise in the last decades, mainly due to rapid industrializing and urbanizing in the Eastern Asia. To identify the characteristics of tropospheric ozone in South Korea, we fitted a sine function to the surface ozone concentration data from 2005 to 2014. Based on fitted sine curves, we analyzed the shifts in the dates on which ozone concentration reached its peak in the calendar year. Ozone monitoring sites can be classified into type types: where the highest annual ozone concentration kept occurring sooner (Esites) and those that kept occurring later (Lsites). The seasonal analysis shows that the surface ozone had increased more rapidly in Esites than in Lsites in the past decade during springtime and vice-versa during summertime. We tried to find the reason for the different seasonal trends with the relationship between ozone and ozone precursors. As a result, it was found that the changes in the ground-level ozone concentration in the spring and summer times are considerably influenced by changes in nitrogen dioxide concentration, and this is closely linked to the destruction (production) process of ozone by nitrogen dioxide in spring (summer). The link between tropospheric ozone and nitrogen dioxide discussed in this study will have to be thoroughly examined through climate-chemistry modeling in the future. Acknowledgements This research was supported by the Korea Ministry of Environment (MOE) as "Climate Change Correspondence Program."

Dobson spectrophotometer ozone measurements during international ozone rocketsonde intercomparison

Science.gov (United States)

Parsons, C. L.

1980-01-01

Measurements of the total ozone content of the atmosphere, made with seven ground based instruments at a site near Wallops Island, Virginia, are discussed in terms for serving as control values with which the rocketborne sensor data products can be compared. These products are profiles of O3 concentration with altitude. By integrating over the range of altitudes from the surface to the rocket apogee and by appropriately estimating the residual ozone amount from apogee to the top of the atmosphere, a total ozone amount can be computed from the profiles that can be directly compared with the ground based instrumentation results. Dobson spectrophotometers were used for two of the ground-based instruments. Preliminary data collected during the IORI from Dobson spectrophotometers 72 and 38 are presented. The agreement between the two and the variability of total ozone overburden through the experiment period are discussed.

Long-term ambient concentrations of total suspended particulates and oxidants as related to incidence of chronic disease in California Seventh-Day Adventists.

Science.gov (United States)

Abbey, D E; Mills, P K; Petersen, F F; Beeson, W L

1991-08-01

Cancer incidence and mortality in a cohort of 6000 nonsmoking California Seventh-Day Adventists were monitored for a 6-year period, and relationships with long-term cumulative ambient air pollution were observed. Total suspended particulates (TSP) and ozone were measured in terms of numbers of hours in excess of several threshold levels corresponding to national standards as well as mean concentration. For all malignant neoplasms among females, risk increased with increasing exceedance frequencies of all thresholds of TSP except the lowest one, and those increased risks were highly statistically significant. For respiratory cancers, increased risk was associated with only one threshold of ozone, and this result was of borderline significance. Respiratory disease symptoms were assessed in 1977 and again in 1987 using the National Heart, Lung and Blood Institute respiratory symptoms questionnaire on a subcohort of 3914 individuals. Multivariate analyses which adjusted for past and passive smoking and occupational exposures indicated statistically significantly (p less than 0.05) elevated relative risks ranging up to 1.7 for incidence of asthma, definite symptoms of airway obstructive disease, and chronic bronchitis with TSP in excess of all thresholds except the lowest one but not for any thresholds of ozone. A trend association (p = 0.056) was noted between the threshold of 10 pphm ozone and incidence of asthma. These results are presented within the context of standards setting for these constituents of air pollution.

Measurement of Ozone Production Sensor

Directory of Open Access Journals (Sweden)

M. Cazorla

2010-05-01

Full Text Available A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS, measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO₂ to O₃, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do in the sample chamber. The air flows that exit the two chambers are sampled by an ozone monitor operating in differential mode so that the difference between the two ozone signals, divided by the exposure time in the chambers, gives the ozone production rate. High-efficiency conversion of NO₂ to O₃ prior to detection in the ozone monitor accounts for differences in the NO_x 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.

Source attribution of tropospheric ozone

Science.gov (United States)

Butler, T. M.

2015-12-01

Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

The ozone backlash

International Nuclear Information System (INIS)

Taubes, G.

1993-01-01

While evidence for the role of chlorofluorocarbons in ozone depletion grows stronger, researchers have recently been subjected to vocal public criticism of their theories-and their motives. Their understanding of the mechanisms of ozone destruction-especially the annual ozone hole that appears in the Antarctic-has grown stronger, yet everywhere they go these days, they seem to be confronted by critics attacking their theories as baseless. For instance, Rush Limbaugh, the conservative political talk-show host and now-best-selling author of The Way Things Ought to Be, regularly insists that the theory of ozone depletion by CFCs is a hoax: bladerdash and poppycock. Zoologist Dixy Lee Ray, former governor of the state of Washington and former head of the Atomic Energy Commission, makes the same argument in her book, Trashing the Planet. The Wall Street Journal and National Review have run commentaries by S. Fred Singer, a former chief scientists for the Department of Transportation, purporting to shoot holes in the theory of ozone depletion. Even the June issue of Omni, a magazine with a circulation of more than 1 million that publishes a mixture of science and science fiction, printed a feature article claiming to expose ozone research as a politically motivated scam

Activation of NMDA receptor by elevated homocysteine in chronic liver disease contributes to encephalopathy.

Science.gov (United States)

Choudhury, Sabanum; Borah, Anupom

2015-07-01

Liver diseases lead to a complex syndrome characterized by neurological, neuro-psychiatric and motor complications, called hepatic encephalopathy, which is prevalent in patients and animal models of acute, sub-chronic and chronic liver failure. Although alterations in GABAergic, glutamatergic, cholinergic and serotonergic neuronal functions have been implicated in HE, the molecular mechanisms that lead to HE in chronic liver disease (CLD) is least illustrated. Due to hepatocellular failure, levels of ammonia and homocysteine (Hcy), in addition to others, are found to increase in the brain as well as plasma. Hcy, a non-protein forming amino acid and an excitotoxin, activates ionotropic glutamate (n-methyl-d-aspartate; NMDA) receptors, and thereby leads to influx of Ca(2+) into neurons, which in turn activates several pathways that trigger oxidative stress, inflammation and apoptosis, collectively called excitotoxicity. Elevated levels of Hcy in the plasma and brain, a condition called Hyperhomocysteinemia (HHcy), and the resultant NMDA receptor-mediated excitotoxicity has been implicated in several diseases, including Parkinson's disease and Alzheimer's disease. Although, hyperammonemia has been shown to cause excitotoxicity, the role of HHcy in the development of behavioral and neurochemical alterations that occur in HE has not been illustrated yet. It is hypothesized that CLD-induced HHcy plays a major role in the development of HE through activation of NMDA receptors. It is further hypothesized that HHcy synergizes with hyperammonemia to activate NMDA receptor in the brain, and thereby cause oxidative stress, inflammation and apoptosis, and neuronal loss that leads to HE. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Global Ozone Climatology from Ozone Soundings via Trajectory Mapping: A Stratospheric Perspective

Science.gov (United States)

Liu, J. J.; Tarasick, D. W.; Fioletov, V. E.; McLinden, C.; Zhao, T.; Gong, S.; Sioris, G.; Jin, J. J.; Liu, G.; Moeini, O.

2013-01-01

This study explores a domain-filling trajectory approach to generate a global ozone climatology from sparse ozonesonde data. Global ozone soundings of 51,898 profiles at 116 stations over 44 years (1965-2008) are used, from which forward and backward trajectories are performed for 4 days, driven by a set of meteorological reanalysis data. Ozone mixing ratios of each sounding from the surface to 26 km altitude are assigned to the entire path along the trajectory. The resulting global ozone climatology is archived monthly for five decades from the 1960s to the 2000s with grids of 5 degree 5 degree 1 km (latitude, longitude, and altitude). It is also archived yearly from 1965 to 2008. This climatology is validated at 20 ozonesonde stations by comparing the actual ozone sounding profile with that found through the trajectories, using the ozone soundings at all the stations except one being tested. The two sets of profiles are in good agreement, both individually with correlation coefficients between 0.975 and 0.998 and root mean square (RMS) differences of 87 to 482 ppbv, and overall with a correlation coefficient of 0.991 and an RMS of 224 ppbv. The ozone climatology is also compared with two sets of satellite data, from the Satellite Aerosol and Gas Experiment (SAGE) and the Optical Spectrography and InfraRed Imager System (OSIRIS). Overall, the ozone climatology compares well with SAGE and OSIRIS data by both seasonal and zonal means. The mean difference is generally under 20 above 15 km. The comparison is better in the northern hemisphere, where there are more ozonesonde stations, than in the southern hemisphere; it is also better in the middle and high latitudes than in the tropics, where assimilated winds are imperfect in some regions. This ozone climatology can capture known features in the stratosphere, as well as seasonal and decadal variations of these features. Furthermore, it provides a wealth of detail about longitudinal variations in the stratosphere such

A Compact Mobile Ozone Lidar for Atmospheric Ozone and Aerosol Profiling

Science.gov (United States)

De Young, Russell; Carrion, William; Pliutau, Denis

2014-01-01

A compact mobile differential absorption lidar (DIAL) system has been developed at NASA Langley Research Center to provide ozone, aerosol and cloud atmospheric measurements in a mobile trailer for ground-based atmospheric ozone air quality campaigns. This lidar is integrated into the Tropospheric Ozone Lidar Network (TOLNet) currently made up of four other ozone lidars across the country. The lidar system consists of a UV and green laser transmitter, a telescope and an optical signal receiver with associated Licel photon counting and analog channels. The laser transmitter consist of a Q-switched Nd:YLF inter-cavity doubled laser pumping a Ce:LiCAF tunable UV laser with all the associated power and lidar control support units on a single system rack. The system has been configured to enable mobile operation from a trailer and was deployed to Denver, CO July 15-August 15, 2014 supporting the DISCOVER-AQ campaign. Ozone curtain plots and the resulting science are presented.

Spatial clustering and meteorological drivers of summer ozone in Europe

Science.gov (United States)

Carro-Calvo, Leopoldo; Ordóñez, Carlos; García-Herrera, Ricardo; Schnell, Jordan L.

2017-10-01

We have applied the k-means clustering technique on a maximum daily 8-h running average near-surface ozone (MDA8 O3) gridded dataset over Europe at 1° × 1° resolution for summer 1998-2012. This has resulted in a spatial division of nine regions where ozone presents coherent spatiotemporal patterns. The role of meteorology in the variability of ozone at different time scales has been investigated by using daily meteorological fields from the NCEP-NCAR meteorological reanalysis. In the five regions of central-southern Europe ozone extremes (exceedances of the summer 95th percentile) occur mostly under anticyclonic circulation or weak sea level pressure gradients which trigger elevated temperatures and the recirculation of air masses. In the four northern regions extremes are associated with high-latitude anticyclones that divert the typical westerly flow at those latitudes and cause the advection of aged air masses from the south. The impact of meteorology on the day-to-day variability of ozone has been assessed by means of two different types of multiple linear models. These include as predictors meteorological fields averaged within the regions (;region-based; approach) or synoptic indices indicating the degree of resemblance between the daily meteorological fields over a large domain (25°-70° N, 35° W - 35° E) and their corresponding composites for extreme ozone days (;index-based; approach). With the first approach, a reduced set of variables, always including daily maximum temperature within the region, explains 47-66% of the variability (adjusted R2) in central-southern Europe, while more complex models are needed to explain 27-49% of the variability in the northern regions. The index-based approach yields better results for the regions of northern Europe, with adjusted R2 = 40-57%. Finally, both methodologies have also been applied to reproduce the interannual variability of ozone, with the best models explaining 66-88% of the variance in central

Evaluation of Global Ozone Monitoring Experiment (GOME) ozone profiles from nine different algorithms

NARCIS (Netherlands)

Meijer, Y.J.; Swart, D.P.J.; Baier, F.; Bhartia, P.K.; Bodeker, G.E.; Casadio, S.; Chance, K.; Frate, Del F.; Erbertseder, T.; Felder, M.D.; Flynn, L.E.; Godin-Beekmann, S.; Hansen, G.; Hasekamp, O.P.; Kaifel, A.; Kelder, H.M.; Kerridge, B.J.; Lambert, J.-C.; Landgraf, J.; Latter, B.G.; Liu, X.; McDermid, I.S.; Pachepsky, Y.; Rozanov, V.; Siddans, R.; Tellmann, S.; A, van der R.J.; Oss, van R.F.; Weber, M.; Zehner, C.

2006-01-01

An evaluation is made of ozone profiles retrieved from measurements of the nadir-viewing Global Ozone Monitoring Experiment (GOME) instrument. Currently, four different approaches are used to retrieve ozone profile information from GOME measurements, which differ in the use of external information

Ozone: The secret greenhouse gas

International Nuclear Information System (INIS)

Berntsen, Terje; Tjernshaugen, Andreas

2001-01-01

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

New dynamic NNORSY ozone profile climatology

Science.gov (United States)

Kaifel, A. K.; Felder, M.; Declercq, C.; Lambert, J.-C.

2012-01-01

Climatological ozone profile data are widely used as a-priori information for total ozone using DOAS type retrievals as well as for ozone profile retrieval using optimal estimation, for data assimilation or evaluation of 3-D chemistry-transport models and a lot of other applications in atmospheric sciences and remote sensing. For most applications it is important that the climatology represents not only long term mean values but also the links between ozone and dynamic input parameters. These dynamic input parameters should be easily accessible from auxiliary datasets or easily measureable, and obviously should have a high correlation with ozone. For ozone profile these parameters are mainly total ozone column and temperature profile data. This was the outcome of a user consultation carried out in the framework of developing a new, dynamic ozone profile climatology. The new ozone profile climatology is based on the Neural Network Ozone Retrieval System (NNORSY) widely used for ozone profile retrieval from UV and IR satellite sounder data. NNORSY allows implicit modelling of any non-linear correspondence between input parameters (predictors) and ozone profile target vector. This paper presents the approach, setup and validation of a new family of ozone profile climatologies with static as well as dynamic input parameters (total ozone and temperature profile). The neural network training relies on ozone profile measurement data of well known quality provided by ground based (ozonesondes) and satellite based (SAGE II, HALOE, and POAM-III) measurements over the years 1995-2007. In total, four different combinations (modes) for input parameters (date, geolocation, total ozone column and temperature profile) are available. The geophysical validation spans from pole to pole using independent ozonesonde, lidar and satellite data (ACE-FTS, AURA-MLS) for individual and time series comparisons as well as for analysing the vertical and meridian structure of different modes of

Bromine measurements in ozone depleted air over the Arctic Ocean

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J. A. Neuman

2010-07-01

Full Text Available In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL. Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS study. Fast (1 s and sensitive (detection limits at the low pptv level measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br₂. Subsequent laboratory studies showed that HOBr rapidly converts to Br₂ on the Teflon instrument inlets. This detected Br₂ is identified as active bromine and represents a lower limit of the sum HOBr + Br₂. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere.

Ozone therapy in periodontics.

Science.gov (United States)

Gupta, G; Mansi, B

2012-02-22

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

Strategies for Worksite Health Interventions to Employees with Elevated Risk of Chronic Diseases

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Lu Meng

2017-06-01

Full Text Available Chronic disease rates have become more prevalent in the modern American workforce, which has negative implications for workplace productivity and healthcare costs. Offering workplace health interventions is recognized as an effective strategy to reduce chronic disease progression, absenteeism, and healthcare costs as well as improve population health. This review documents intervention and evaluation strategies used for health promotion programs delivered in workplaces. Using predetermined search terms in five online databases, we identified 1,131 published items from 1995 to 2014. Of these items, 27 peer-reviewed articles met the inclusion criteria; reporting data from completed United States-based workplace interventions that recruited at-risk employees based on their disease or disease-related risk factors. A content rubric was developed and used to catalogue these 27 published field studies. Selected workplace interventions targeted obesity (n = 13, cardiovascular diseases (n = 8, and diabetes (n = 6. Intervention strategies included instructional education/counseling (n = 20, workplace environmental change (n = 6, physical activity (n = 10, use of technology (n = 10, and incentives (n = 13. Self-reported data (n = 21, anthropometric measurements (n = 17, and laboratory tests (n = 14 were used most often in studies with outcome evaluation. This is the first literature review to focus on interventions for employees with elevated risk for chronic diseases. The review has the potential to inform future workplace health interventions by presenting strategies related to implementation and evaluation strategies in workplace settings. These strategies can help determine optimal worksite health programs based on the unique characteristics of work settings and the health risk factors of their employee populations.

Strategies for Worksite Health Interventions to Employees with Elevated Risk of Chronic Diseases.

Science.gov (United States)

Meng, Lu; Wolff, Marilyn B; Mattick, Kelly A; DeJoy, David M; Wilson, Mark G; Smith, Matthew Lee

2017-06-01

Chronic disease rates have become more prevalent in the modern American workforce, which has negative implications for workplace productivity and healthcare costs. Offering workplace health interventions is recognized as an effective strategy to reduce chronic disease progression, absenteeism, and healthcare costs as well as improve population health. This review documents intervention and evaluation strategies used for health promotion programs delivered in workplaces. Using predetermined search terms in five online databases, we identified 1,131 published items from 1995 to 2014. Of these items, 27 peer-reviewed articles met the inclusion criteria; reporting data from completed United States-based workplace interventions that recruited at-risk employees based on their disease or disease-related risk factors. A content rubric was developed and used to catalogue these 27 published field studies. Selected workplace interventions targeted obesity ( n   =  13), cardiovascular diseases ( n   =  8), and diabetes ( n   =  6). Intervention strategies included instructional education/counseling ( n   =  20), workplace environmental change ( n   =  6), physical activity ( n   =  10), use of technology ( n   =  10), and incentives ( n   =  13). Self-reported data ( n   =  21), anthropometric measurements ( n   =  17), and laboratory tests ( n   =  14) were used most often in studies with outcome evaluation. This is the first literature review to focus on interventions for employees with elevated risk for chronic diseases. The review has the potential to inform future workplace health interventions by presenting strategies related to implementation and evaluation strategies in workplace settings. These strategies can help determine optimal worksite health programs based on the unique characteristics of work settings and the health risk factors of their employee populations.

OZONE ABSORPTION IN RAW WATERS

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LJILJANA TAKIĆ

2008-03-01

Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

Influence of the ozone profile above Madrid (Spain) on Brewer estimation of ozone air mass factor

Energy Technology Data Exchange (ETDEWEB)

Anton, M. [Univ. de Extremadura, Badajoz (Spain). Dept. de Fisica; Evora Univ. (PT). Goephysics Centre of Evora (CGE); Lopez, M.; Banon, M. [Agenica Estatal de Meteorologia (AEMET), Madrid (Spain); Costa, M.J.; Silva, A.M. [Evora Univ. (PT). Goephysics Centre of Evora (CGE); Evora Univ. (Portugal). Dept. of Physics; Serrano, A. [Univ. de Extremadura, Badajoz (Spain). Dept. de Fisica; Bortoli, D. [Evora Univ. (PT). Goephysics Centre of Evora (CGE); Vilaplana, J.M. [Instituto Nacional de Tecnica Aeroespacial (INTA), Huelva (Spain). Estacion de Sondeos Atmosferico ' ' El Arenosillo' '

2009-07-01

The methodology used by Brewer spectroradiometers to estimate the ozone column is based on differential absorption spectroscopy. This methodology employs the ozone air mass factor (AMF) to derive the total ozone column from the slant path ozone amount. For the calculating the ozone AMF, the Brewer algorithm assumes that the ozone layer is located at a fixed height of 22 km. However, for a real specific site the ozone presents a certain profile, which varies spatially and temporally depending on the latitude, altitude and dynamical conditions of the atmosphere above the site of measurements. In this sense, this work address the reliability of the mentioned assumption and analyses the influence of the ozone profiles measured above Madrid (Spain) in the ozone AMF calculations. The approximated ozone AMF used by the Brewer algorithm is compared with simulations obtained using the libRadtran radiative transfer model code. The results show an excellent agreement between the simulated and the approximated AMF values for solar zenith angle lower than 75 . In addition, the relative differences remain lower than 2% at 85 . These good results are mainly due to the fact that the altitude of the ozone layer assumed constant by the Brewer algorithm for all latitudes notably can be considered representative of the real profile of ozone above Madrid (average value of 21.7{+-}1.8 km). The operational ozone AMF calculations for Brewer instruments are limited, in general, to SZA below 80 . Extending the usable SZA range is especially relevant for Brewer instruments located at high mid-latitudes. (orig.)

Chronic restraint stress after injury and shock is associated with persistent anemia despite prolonged elevation in erythropoietin levels.

Science.gov (United States)

Bible, Letitia E; Pasupuleti, Latha V; Gore, Amy V; Sifri, Ziad C; Kannan, Kolenkode B; Mohr, Alicia M

2015-07-01

Following severe traumatic injury, critically ill patients have a prolonged hypercatacholamine state that is associated with bone marrow (BM) dysfunction and persistent anemia. However, current animal models of injury and shock result in a transient anemia. Daily restraint stress (chronic stress [CS]) has been shown to increase catecholamines. We hypothesize that adding CS following injury or injury and shock in rats will prolong the hypercatecholaminemia and prolong the initial anemia, despite elevated erythropoietin (EPO) levels. Male Sprague-Dawley rats (n = 6-8 per group) underwent lung contusion (LC) or combined LC/hemorrhagic shock (LCHS) followed by 6 days of CS. CS consisted of a 2-hour restraint period interrupted with repositioning and alarms every 30 minutes. At 7 days, urine was assessed for norepinephrine (NE) levels, blood for EPO and hemoglobin (Hgb), and BM for erythroid progenitor growth. Animals undergoing LC or combined LCHS predictably recovered by Day 7; urine NE, EPO, and Hgb levels were normal. The addition of CS to LC and LCHS models was associated with a significant elevation in NE on Day 6. The addition of CS to LC led to a persistent 20% to 25% decrease in the growth of BM hematopoietic progenitor cells. These findings were further exaggerated when CS was added following LCHS, resulting in a 20%q to 40% reduction in BM erythroid progenitor colony growth and a 20% decrease in Hgb when compared with LCHS alone. Exposing injured animals to CS results in prolonged elevation of NE and EPO, which is associated with worsening BM erythroid function and persistent anemia. Chronic restraint stress following injury and shock provides a clinically relevant model to further evaluate persistent injury-associated anemia seen in critically ill trauma patients. Furthermore, alleviating CS after severe injury is a potential therapeutic target to improve BM dysfunction and anemia.

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

Science.gov (United States)

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

2004-09-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Evaluation of ozone profile and tropospheric ozone retrievals from GEMS and OMI spectra

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J. Bak

2013-02-01

Full Text Available South Korea is planning to launch the GEMS (Geostationary Environment Monitoring Spectrometer instrument into the GeoKOMPSAT (Geostationary Korea Multi-Purpose SATellite platform in 2018 to monitor tropospheric air pollutants on an hourly basis over East Asia. GEMS will measure backscattered UV radiances covering the 300–500 nm wavelength range with a spectral resolution of 0.6 nm. The main objective of this study is to evaluate ozone profiles and stratospheric column ozone amounts retrieved from simulated GEMS measurements. Ozone Monitoring Instrument (OMI Level 1B radiances, which have the spectral range 270–500 nm at spectral resolution of 0.42–0.63 nm, are used to simulate the GEMS radiances. An optimal estimation-based ozone profile algorithm is used to retrieve ozone profiles from simulated GEMS radiances. Firstly, we compare the retrieval characteristics (including averaging kernels, degrees of freedom for signal, and retrieval error derived from the 270–330 nm (OMI and 300–330 nm (GEMS wavelength ranges. This comparison shows that the effect of not using measurements below 300 nm on retrieval characteristics in the troposphere is insignificant. However, the stratospheric ozone information in terms of DFS decreases greatly from OMI to GEMS, by a factor of ∼2. The number of the independent pieces of information available from GEMS measurements is estimated to 3 on average in the stratosphere, with associated retrieval errors of ~1% in stratospheric column ozone. The difference between OMI and GEMS retrieval characteristics is apparent for retrieving ozone layers above ~20 km, with a reduction in the sensitivity and an increase in the retrieval errors for GEMS. We further investigate whether GEMS can resolve the stratospheric ozone variation observed from high vertical resolution Earth Observing System (EOS Microwave Limb Sounder (MLS. The differences in stratospheric ozone profiles between GEMS and MLS are comparable to those

Soil respiration, root biomass, and root turnover following long-term exposure of northern forests to elevated atmospheric CO2 and tropospheric O3

Science.gov (United States)

Kurt S. Pregitzer; Andrew J. Burton; John S. King; Donald R. Zak

2008-01-01

The Rhinelander free-air CO2 enrichment (FACE) experiment is designed to understand ecosystem response to elevated atmospheric carbon dioxide (+CO2) and elevated tropospheric ozone (+O3). The objectives of this study were: to understand how soil respiration responded to the experimental treatments; to...

Ozone as an air pollutant

DEFF Research Database (Denmark)

Berg, Rolf W.

1996-01-01

A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995.......A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995....

The effects of global changes upon regional ozone pollution in the United States

Science.gov (United States)

Chen, J.; Avise, J.; Lamb, B.; Salathé, E.; Mass, C.; Guenther, A.; Wiedinmyer, C.; Lamarque, J.-F.; O'Neill, S.; McKenzie, D.; Larkin, N.

2009-02-01

A comprehensive numerical modeling framework was developed to estimate the effects of collective global changes upon ozone pollution in the US in 2050. The framework consists of the global climate and chemistry models, PCM (Parallel Climate Model) and MOZART-2 (Model for Ozone and Related Chemical Tracers v.2), coupled with regional meteorology and chemistry models, MM5 (Mesoscale Meteorological model) and CMAQ (Community Multi-scale Air Quality model). The modeling system was applied for two 10-year simulations: 1990-1999 as a present-day base case and 2045-2054 as a future case. For the current decade, the daily maximum 8-h moving average (DM8H) ozone mixing ratio distributions for spring, summer and fall showed good agreement with observations. The future case simulation followed the Intergovernmental Panel on Climate Change (IPCC) A2 scenario together with business-as-usual US emission projections and projected alterations in land use, land cover (LULC) due to urban expansion and changes in vegetation. For these projections, US anthropogenic NOx (NO+NO2) and VOC (volatile organic carbon) emissions increased by approximately 6% and 50%, respectively, while biogenic VOC emissions decreased, in spite of warmer temperatures, due to decreases in forested lands and expansion of croplands, grasslands and urban areas. A stochastic model for wildfire emissions was applied that projected 25% higher VOC emissions in the future. For the global and US emission projection used here, regional ozone pollution becomes worse in the 2045-2054 period for all months. Annually, the mean DM8H ozone was projected to increase by 9.6 ppbv (22%). The changes were higher in the spring and winter (25%) and smaller in the summer (17%). The area affected by elevated ozone within the US continent was projected to increase; areas with levels exceeding the 75 ppbv ozone standard at least once a year increased by 38%. In addition, the length of the ozone season was projected to increase with

Determination of the Optimum Ozone Product on the Plasma Ozonizer

International Nuclear Information System (INIS)

Agus Purwadi; Widdi Usada; Suryadi; Isyuniarto; Sri Sukmajaya

2002-01-01

An experiment of the optimum ozone product determination on the cylindrical plasma ozonizer has been done. The experiment is carried out by using alternating high voltage power supply, oscilloscope CS-1577 A, flow meter and spectronik-20 instrument for the absorbance solution samples which produced by varying the physics parameter values of the discharge alternating high voltage and velocity of oxygen gas input. The plasma ozonizer is made of cylinder stainless steel as the electrode and cylinder glass as the dielectric with 1.00 mm of the discharge gap and 7.225 mm 3 of the discharge tube volume. The experiment results shows that the optimum ozone product is 0.360 mg/s obtained at the the discharge of alternating high voltage of 25.50 kV, the frequency of 1.00 kHz and the rate of oxygen gas input of 1.00 lpm. (author)

Tropospheric Ozone Pollution from Space: New Views from the TOMS (Total Ozone Mapping Spectrometer) Instrument

Science.gov (United States)

Thompson, Anne M.; Hudson, Robert D.; Frolov, Alexander D.; Witte, Jacquelyn C.; Kucsera, Tom L.; Einaudi, Franco (Technical Monitor)

2000-01-01

New products from the TOMS (Total Ozone Mapping Spectrometer) >satellite instrument can resolve pollution events in tropical and mid-latitudes, Over the past several years, we have developed tropospheric ozone data sets by two methods. The modified-residual technique [Hudson and Thompson, 1998; Thompson and Hudson, 1999] uses v. 7 TOMS total ozone and is applicable to tropical regimes in which the wave-one pattern in total ozone is observed. The TOMSdirect method [Hudson et at., 2000] represents a new algorithm that uses TOMS radiances to extract tropospheric ozone in regions of constant stratospheric ozone and tropospheric ozone displaying high mixing ratios and variability characteristic of pollution, Absorbing aerosols (dust and smoke; Herman et at., 1997 Hsu et al., 1999), a standard TOMS product, provide transport and/or source marker information to interpret tropospheric ozone. For the Nimbus 7/TOMS observing period (1979-1992), modified-residual TTO (tropical tropospheric ozone) appears as two maps/month at I-degree latitude 2-degree longitude resolution at a homepage and digital data are available (20S to 20N) by ftp at http://metosrv2. umd.edu/tropo/ 14y_data.d. Preliminary modified-residual TTO data from the operational Earth-Probe/TOMS (1996- present) are posted in near-real-time at the same website. Analyses with the new tropospheric ozone and aerosol data are illustrated by the following (I)Signals in tropical tropospheric ozone column and smoke amount during ENSO (El Nino-Southern Oscillation) events, e.g. 1982-1983 and the intense ENSO induced biomass fires of 1997-1998 over the Indonesian region [Thompson et a[, 2000a, Thompson and Hudson, 1999]. (2) Trends in tropospheric ozone and smoke aerosols in various tropical regions (Atlantic, Pacific, Africa, Brazil). No significant trends were found for ozone from1980-1990 [Thompson and Hudson, 19991 although smoke aerosols increased during the period [Hsu et al.,1999]. (3) Temporal and spatial offsets

Mortality for chronic-degenerative diseases in Tuscany: Ecological study comparing neighboring areas with substantial differences in environmental pollution.

Science.gov (United States)

Marabotti, Claudio; Piaggi, Paolo; Scarsi, Paolo; Venturini, Elio; Cecchi, Romina; Pingitore, Alessandro

2017-06-19

Environmental pollution is associated with morbidity and mortality for chronic-degenerative diseases. Recent data points out a relationship between proximity to industrial plants and mortality due to neoplasms. The aim of this study has been to compare mortality due to chronic-degenerative diseases in the area of Tuscany (Bassa Val di Cecina), Italy, characterized by the presence of 2 neighboring municipalities similar in terms of size but with substantial differences in industrial activities: Rosignano (the site of chemical, energy production and waste processing industries) and Cecina (with no polluting activity). Standardized mortality rates for the 2001-2010 decade were calculated; the data of the whole Tuscany was assumed as reference. Environmental levels of pollutants were obtained by databases of the Environmental Protection Agency of Tuscany Region (Agenzia Regionale per la Protezione Ambientale della Toscana - ARPAT). Maximum tolerated pollutant levels set by national laws were assumed as reference. In the whole Bassa Val di Cecina, significantly elevated standardized mortality rates due to mesothelioma, ischemic heart diseases, cerebrovascular diseases and Alzheimer and other degenerative diseases of nervous system were observed. In the municipality of Rosignano, a significant excess of mortality for all these groups of diseases was confirmed. On the contrary, the municipality of Cecina showed only significantly higher mortality rates for ischemic heart diseases. Elevated levels of heavy metals in sea water and of particulate matter which contains particles of diameter ≤ 10 mm (PM10) and ozone in air were detected in Rosignano. This study shows an excess of mortality for chronic-degenerative diseases in the area with elevated concentration of polluting factories. Proximity to industrial plants seems to represent a risk factor for those diseases. Int J Occup Med Environ Health 2017;30(4):641-653. This work is available in Open Access model and licensed

Mortality for chronic-degenerative diseases in Tuscany: Ecological study comparing neighboring areas with substantial differences in environmental pollution

Directory of Open Access Journals (Sweden)

Claudio Marabotti

2017-08-01

Full Text Available Objectives: Environmental pollution is associated with morbidity and mortality for chronic-degenerative diseases. Recent data points out a relationship between proximity to industrial plants and mortality due to neoplasms. The aim of this study has been to compare mortality due to chronic-degenerative diseases in the area of Tuscany (Bassa Val di Cecina, Italy, characterized by the presence of 2 neighboring municipalities similar in terms of size but with substantial differences in industrial activities: Rosignano (the site of chemical, energy production and waste processing industries and Cecina (with no polluting activity. Material and Methods: Standardized mortality rates for the 2001–2010 decade were calculated; the data of the whole Tuscany was assumed as reference. Environmental levels of pollutants were obtained by databases of the Environmental Protection Agency of Tuscany Region (Agenzia Regionale per la Protezione Ambientale della Toscana – ARPAT. Maximum tolerated pollutant levels set by national laws were assumed as reference. Results: In the whole Bassa Val di Cecina, significantly elevated standardized mortality rates due to mesothelioma, ischemic heart diseases, cerebrovascular diseases and Alzheimer and other degenerative diseases of nervous system were observed. In the municipality of Rosignano, a significant excess of mortality for all these groups of diseases was confirmed. On the contrary, the municipality of Cecina showed only significantly higher mortality rates for ischemic heart diseases. Elevated levels of heavy metals in sea water and of particulate matter which contains particles of diameter ≤ 10 mm (PM10 and ozone in air were detected in Rosignano. Conclusions: This study shows an excess of mortality for chronic-degenerative diseases in the area with elevated concentration of polluting factories. Proximity to industrial plants seems to represent a risk factor for those diseases. Int J Occup Med Environ Health

Quantifying the contributions to stratospheric ozone changes from ozone depleting substances and greenhouse gases

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D. A. Plummer

2010-09-01

Full Text Available A state-of-the-art chemistry climate model coupled to a three-dimensional ocean model is used to produce three experiments, all seamlessly covering the period 1950–2100, forced by different combinations of long-lived Greenhouse Gases (GHGs and Ozone Depleting Substances (ODSs. The experiments are designed to quantify the separate effects of GHGs and ODSs on the evolution of ozone, as well as the extent to which these effects are independent of each other, by alternately holding one set of these two forcings constant in combination with a third experiment where both ODSs and GHGs vary. We estimate that up to the year 2000 the net decrease in the column amount of ozone above 20 hPa is approximately 75% of the decrease that can be attributed to ODSs due to the offsetting effects of cooling by increased CO₂. Over the 21st century, as ODSs decrease, continued cooling from CO₂ is projected to account for more than 50% of the projected increase in ozone above 20 hPa. Changes in ozone below 20 hPa show a redistribution of ozone from tropical to extra-tropical latitudes with an increase in the Brewer-Dobson circulation. In addition to a latitudinal redistribution of ozone, we find that the globally averaged column amount of ozone below 20 hPa decreases over the 21st century, which significantly mitigates the effect of upper stratospheric cooling on total column ozone. Analysis by linear regression shows that the recovery of ozone from the effects of ODSs generally follows the decline in reactive chlorine and bromine levels, with the exception of the lower polar stratosphere where recovery of ozone in the second half of the 21st century is slower than would be indicated by the decline in reactive chlorine and bromine concentrations. These results also reveal the degree to which GHG-related effects mute the chemical effects of N₂O on ozone in the standard future scenario used for the WMO Ozone Assessment. Increases in the

Measurement of amino acid levels in the vitreous humor of rats after chronic intraocular pressure elevation or optic nerve transection.

Science.gov (United States)

Levkovitch-Verbin, Hana; Martin, Keith R G; Quigley, Harry A; Baumrind, Lisa A; Pease, Mary Ellen; Valenta, Danielle

2002-10-01

To investigate whether the levels of free amino acids and protein in the vitreous of rat eyes are altered with chronic intraocular pressure (IOP) elevation or after optic nerve transection. The concentrations of 20 amino acids in the vitreous humor were measured by high-performance liquid chromatography in both eyes of 41 rats with unilateral IOP elevation induced by translimbal photocoagulation. Eyes were studied 1 day and 1, 2, 4, and 9 weeks after initial IOP elevation. The same amino acids were measured in 41 rats 1 day and 2, 4, and 9 weeks after unilateral transection of the orbital optic nerve. The intravitreal protein level was assayed in additional 22 rats with IOP elevation and 12 rats after nerve transection. Two masked observers evaluated the amount of optic nerve damage with a semiquantitative, light-microscopic technique. In rats with experimental glaucoma, amino acid concentrations were unchanged 1 day after treatment. At 1 week, 4 of 20 amino acids (aspartate, proline, alanine, and lysine) were higher than in control eyes ( 0.05). Vitreous protein level was significantly higher in glaucomatous eyes than their paired controls at 1 day ( 0.01).

Future heat waves and surface ozone

Science.gov (United States)

Meehl, Gerald A.; Tebaldi, Claudia; Tilmes, Simone; Lamarque, Jean-Francois; Bates, Susan; Pendergrass, Angeline; Lombardozzi, Danica

2018-06-01

A global Earth system model is used to study the relationship between heat waves and surface ozone levels over land areas around the world that could experience either large decreases or little change in future ozone precursor emissions. The model is driven by emissions of greenhouse gases and ozone precursors from a medium-high emission scenario (Representative Concentration Pathway 6.0–RCP6.0) and is compared to an experiment with anthropogenic ozone precursor emissions fixed at 2005 levels. With ongoing increases in greenhouse gases and corresponding increases in average temperature in both experiments, heat waves are projected to become more intense over most global land areas (greater maximum temperatures during heat waves). However, surface ozone concentrations on future heat wave days decrease proportionately more than on non-heat wave days in areas where ozone precursors are prescribed to decrease in RCP6.0 (e.g. most of North America and Europe), while surface ozone concentrations in heat waves increase in areas where ozone precursors either increase or have little change (e.g. central Asia, the Mideast, northern Africa). In the stabilized ozone precursor experiment, surface ozone concentrations increase on future heat wave days compared to non-heat wave days in most regions except in areas where there is ozone suppression that contributes to decreases in ozone in future heat waves. This is likely associated with effects of changes in isoprene emissions at high temperatures (e.g. west coast and southeastern North America, eastern Europe).

Study of the superficial ozone concentrations in the atmosphere of Comunidad de Madrid using passive samplers

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D. Galán Madruga

2001-06-01

Full Text Available The ozone is a secondary atmospheric pollutant which is generated for photochemical reactions of volatil organic compounds (VOC’s and nitrogen oxides (NOx. In Spain the ozone is a big problem as a consequence of the solar radiation to reach high levels. Exposure over a period of time to elevated ozone concentrations can cause damage in the public health and alterations in the vegetation.The aim of this study is to carry out the development and validation of a measurement method to let asses the superficial ozone levels in the Comunidad de Madrid, by identifing the zones more significants, where to measure with UV photometric monitors (automatics methods this pollutant and where the health and the vegetation can be affected. To such effect, passive samplers are used, which have glass fiber filters coated with a solution of sodium nitrite, potassium carbonate, glycerol and water. The nitrite ion in the presence of ozone is oxidized to nitrato ion, which it is extrated with ultrapure water and analyzed for ion chromatography, by seen proportional to the concentration existing in the sampling point.The results of validation from field tests indicate a excellent correlation between the passive and the automatic method.The higher superficial ozone concentrations are placed in rural zones, distanced of emission focus of primary pollutants (nitrogen oxides and volatil organic compounds... principally in direction soutwest and northwest of the Comunidad of Madrid.

A DIGE analysis of developing poplar leaves subjected to ozone reveals major changes in carbon metabolism.

Science.gov (United States)

Bohler, Sacha; Bagard, Matthieu; Oufir, Mouhssin; Planchon, Sébastien; Hoffmann, Lucien; Jolivet, Yves; Hausman, Jean-François; Dizengremel, Pierre; Renaut, Jenny

2007-05-01

Tropospheric ozone pollution is described as having major negative effects on plants, compromising plant survival. Carbon metabolism is especially affected. In the present work, the effects of chronic ozone exposure were evaluated at the proteomic level in developing leaves of young poplar plants exposed to 120 ppb of ozone for 35 days. Soluble proteins (excluding intrinsic membrane proteins) were extracted from leaves after 3, 14 and 35 days of ozone exposure, as well as 10 days after a recovery period. Proteins (pI 4 to 7) were analyzed by 2-D DIGE experiments, followed by MALDI-TOF-TOF identification. Additional observations were obtained on growth, lesion formation, and leaf pigments analysis. Although treated plants showed large necrotic spots and chlorosis in mature leaves, growth decreased only slightly and plant height was not affected. The number of abscised leaves was higher in treated plants, but new leaf formation was not affected. A decrease in chlorophylls and lutein contents was recorded. A large number of proteins involved in carbon metabolism were identified. In particular, proteins associated with the Calvin cycle and electron transport in the chloroplast were down-regulated. In contrast, proteins associated with glucose catabolism increased in response to ozone exposure. Other identified enzymes are associated with protein folding, nitrogen metabolism and oxidoreductase activity.

Ozone health effects

International Nuclear Information System (INIS)

Easterly, C.

1994-01-01

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

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers

International Nuclear Information System (INIS)

Burkey, Kent O.; Neufeld, Howard S.; Souza, Lara; Chappelka, Arthur H.; Davison, Alan W.

2006-01-01

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 μmol g -1 fresh weight) than crown-beard (2-4 μmol g -1 fresh weight) or cutleaf coneflower (0.5-2 μmol g -1 fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g -1 fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity. - Wildflower species exhibit differences in ascorbic acid content and redox status that affect ozone sensitivity

"OZONE SOURCE APPORTIONMENT IN CMAQ' | Science ...

Science.gov (United States)

Ozone source attribution has been used to support various policy purposes including interstate transport (Cross State Air Pollution Rule) by U.S. EPA and ozone nonattainment area designations by State agencies. Common scientific applications include tracking intercontinental transport of ozone and ozone precursors and delineating anthropogenic and non-anthropogenic contribution to ozone in North America. As in the public release due in September 2013, CMAQ’s Integrated Source Apportionment Method (ISAM) attributes PM EC/OC, sulfate, nitrate, ammonium, ozone and its precursors NOx and VOC, to sectors/regions of users’ interest. Although the peroxide-to-nitric acid productions ratio has been the most common indicator to distinguish NOx-limited ozone production from VOC-limited one, other indicators are implemented in addition to allowing for an ensemble decision based on a total of 9 available indicator ratios. Moreover, an alternative approach of ozone attribution based on the idea of chemical sensitivity in a linearized system that has formed the basis of chemical treatment in forward DDM/backward adjoint tools has been implemented in CMAQ. This method does not require categorization into either ozone regime. In this study, ISAM will simulate the 2010 North America ozone using all of the above gas-phase attribution methods. The results are to be compared with zero-out difference out of those sectors in the host model runs. In addition, ozone contribution wil

Advanced treatment of biotreated textile industry wastewater with ozone, virgin/ozonated granular activated carbon and their combination.

Science.gov (United States)

Arslan-Alaton, Idil; Seremet, Ozden

2004-01-01

Biotreated textile wastewater (CODo = 248 mg L(-1); TOCo = 58 mg L(-1); A620 = 0.007 cm(-1); A525 = 0.181 cm(-1); A436 = 0.198 cm(-1)) was subjected to advanced treatment with ozonation, granular activated carbon (GAC) adsorption in serial and simultaneous applications. Experiments were conducted to investigate the effects of applied ozone dose, ozone absorption rate, specific ozone absorption efficiency, GAC dose, and reaction pH on the treatment performance of the selected tertiary treatment scheme. In separate experiments, the impact of virgin GAC ozonation on its adsorptive capacity for biotreated and biotreated + ozonated textile effluent was also investigated. Ozonation appeared to be more effective for decolorization (kd = 0.15 min(-1) at pH = 3), whereas GAC adsorption yielded higher COD removal rates (54% at pH = 3). It was also found that GAC addition (4 g/L) at pH = 7 and 9 enhanced the COD abatement rate of the ozonation process significantly and that the sequential application of ozonation (at pH = 3-11, 675 mg L(-1) O3) followed by GAC adsorption (at pH = 3-7, 10 g L(-1) GAC) resulted in the highest treatment performances both in terms of color and COD reduction. Simultaneous application of GAC and ozone at acidic and alkaline pH seriously inhibited COD abatement rates as a consequence of competitive adsorption and partial oxidation of textile components and GAC. It could also be established that ozone absorption efficiency decreased after color removal was complete. Ozonation of biotreated textile wastewater with 113 mg L(-1) ozone resulted in an appreciable enhancement of GAC adsorptive capacity in terms of residual color removal. Ozonation of GAC at relatively low doses (= 10.8 mg/g GAC) did not improve its overall adsorption capacity.

Effects of elevated concentrations of atmospheric CO{sub 2} and tropospheric O{sub 3} on leaf litter production and chemistry in trembling aspen and paper birch communities

Energy Technology Data Exchange (ETDEWEB)

Liu, L.; King, J.S. [Michigan Technological Univ., Houghton, MI (United States). School of Forest Resources and Environmental Science; Giardina, C.P. [United States Dept. of Agriculture Forest Service, Houghton, MI (United States)

2005-12-01

This study examined the effects of elevated carbon dioxide (CO{sub 2}) and elevated ozone (O{sub 3}) on the quantity and timing of nutrient release to plants and on soil carbon formation rates, and how they are influenced by the combined change in litter quality and quantity. The changes in leaf litter in response to environmental changes was characterized in order to understand the influence of global change on forests. Free-air CO{sub 2} enrichment (FACE) technology was used to examine leaf litter production and biochemical input to soil in response to elevated CO{sub 2} and O{sub 3} treatments. The study involved collecting litter from aspen and birch-aspen communities that had been exposed to FACE and O{sub 3} treatments for 6 years. The hypothesis of growth differentiation balance was used as the basis to develop other hypotheses regarding litter chemistry responses to elevated levels of carbon dioxide and ozone. It was assumed that environmental factors that increase the net balance of plant carbon sources relative to growth sinks will increase the allocation of photosynthate to the production of carbon-based secondary compounds. Litter was analyzed for concentrations of carbon, nitrogen, soluble sugars, lipids, lignin, cellulose, hemicellulose and carbon-based defensive compounds such as soluble phenolics and condensed tannins. The study showed that high levels of ozone greatly increased litter concentrations of soluble sugars, soluble phenolics and condensed tannins, but there were no major effects of elevated carbon dioxide or elevated ozone on the concentrations of individual carbon structural carbon hydrates such as cellulose, hemicellulose and lignin. It was concluded that in the future, the inputs of nitrogen, soluble sugars, condensed tannins, soluble phenolics, cellulose and lignin to forest soils can change as a result of small changes in litter chemistry resulting from elevated CO{sub 2}, tropospheric O{sub 3}, and changes in litter biomass

Effects of ozone on the pain and disability in patients with failed back surgery syndrome

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Danilo Costa Barbosa

Full Text Available Summary Introduction: Low back pain is one of the painful disorders of higher prevalence. It has several etiologies and surgery may be indicated in the presence of neurological deficits or compression syndromes. However, in up to 40% of cases, patients develop worsening of pain and failed back surgery syndrome (FBSS, which is an important cause of chronic pain with high morbidity and disability. In the last two decades, ozone has been shown to be a new therapeutic option for FBSS due to its analgesic and anti-inflammatory properties. Objective: To evaluate the effect of ozone therapy on pain and disability in patients with failed back surgery syndrome. Method: We selected 19 patients undergoing epiduroscopy and injection of ozone. Patients were evaluated preoperatively and 21 days after the procedure, using the following instruments: Visual Analogue Scale (VAS, Brief Pain Inventory, Roland-Morris Questionnaire Disability, Oswestry Disability Index (ODI, Neuropathic Pain Symptom Inventory and Douleur Neuropathique 4. Results: The patients showed significant pain relief, but no improvement was observed in the functional scales. Conclusion: Our results suggest that epidural ozone therapy can be a treatment option in FBSS to reduce the intensity of the pain.

Optical remote measurement of ozone in cirrus clouds; Optische Fernmessung von Ozon in Zirruswolken

Energy Technology Data Exchange (ETDEWEB)

Reichardt, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physikalische und Chemische Analytik

1998-12-31

The subject of this thesis is theoretical and experimental investigations into the simultaneous optical remote measurement of atmospheric ozone concentration and particle properties. A lidar system was developed that combines the Raman-lidar and the polarization-lidar with the Raman-DIAL technique. An error analysis is given for ozone measurements in clouds. It turns out that the wavelength dependencies of photon multiple scattering and of the particle extinction coefficient necessitate a correction of the measured ozone concentration. To quantify the cloud influence, model calculations based on particle size distributions of spheres are carried out. The most important experimental result of this thesis is the measured evidence of pronounced minima in the ozone distribution in a humid upper troposphere shortly before and during cirrus observation. Good correlation between ozone-depleted altitude ranges and ice clouds is found. This finding is in contrast to ozone profiles measured in a dry and cloud-free troposphere. (orig.) 151 refs.

Experimental study of ozone synthesis

International Nuclear Information System (INIS)

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

2002-01-01

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

Ozone kinetics in low-pressure discharges

Science.gov (United States)

Guerra, Vasco; Marinov, Daniil; Guaitella, Olivier; Rousseau, Antoine

2012-10-01

Ozone kinetics is quite well established at atmospheric pressure, due to the importance of ozone in atmospheric chemistry and to the development of industrial ozone reactors. However, as the pressure is decreased and the dominant three-body reactions lose importance, the main mechanisms involved in the creation and destruction of ozone are still surrounded by important uncertainties. In this work we develop a self-consistent model for a pulsed discharge and its afterglow operating in a Pyrex reactor with inner radius 1 cm, at pressures in the range 1-5 Torr and discharge currents of 40-120 mA. The model couples the electron Boltzmann equation with a system of equations for the time evolution of the heavy particles. The calculations are compared with time-dependent measurements of ozone and atomic oxygen. Parametric studies are performed in order to clarify the role of vibrationally excited ozone in the overall kinetics and to establish the conditions where ozone production on the surface may become important. It is shown that vibrationally excited ozone does play a significant role, by increasing the time constants of ozone formation. Moreover, an upper limit for the ozone formation at the wall in these conditions is set at 10(-4).

Physicochemical patterns of ozone absorption by wood

Science.gov (United States)

Mamleeva, N. A.; Lunin, V. V.

2016-11-01

Results from studying aspen and pine wood ozonation are presented. The effect the concentration of ozone, the reagent residence time, and the content of water in a sample of wood has on ozone consumption rate and ozone demand are analyzed. The residence time is shown to determine the degree of ozone conversion degree and the depth of substrate destruction. The main patterns of ozone absorption by wood with different moisture content are found. Ways of optimizing the ozonation of plant biomass are outlined.

Ozone, nitric acid, and ammonia air pollution is unhealthy for people and ecosystems in southern Sierra Nevada, California

Science.gov (United States)

R. Cisneros; A. Bytnerowicz; D. Schweizer; S. Zhong; S. Traina; D.H. Bennett

2010-01-01

Two-week average concentrations of ozone (O3), nitric acid vapor (HNO3) and ammonia (NH3) were measured with passive samplers during the 2002 summer season across the central Sierra Nevada Mountains, California, along the San Joaquin River drainage. Elevated concentrations of the pollutants were...

Comparison of measured and modeled surface ozone concentrations at two different sites in Europe during the solar eclipse on August 11, 1999

International Nuclear Information System (INIS)

Zanis, P.; Zerefos, C.S.; Melas, D.

2001-01-01

The effects of the solar eclipse on 11 August 1999 on surface ozone at two sites, Thessaloniki, Greece (urban site) and Hohenpeissenberg, Germany (elevated rural site) are investigated in this study and compared with model results. The eclipse offered a unique opportunity to test our understanding of tropospheric ozone chemistry and to investigate with a simple photochemical box model the response of surface ozone to changes of solar radiation during a photolytical perturbation such as the solar eclipse. The surface ozone measurements following the eclipse display a decrease of around 10-15 ppbv at the urban station of Eptapyrgio at Thessaloniki while at Hoheneissenberg, the actual ozone data do not show any clear effect of eclipse on surface ozone. For Thessaloniki, the model results suggest that solely photochemistry can account for a significant amount of the observed surface ozone decrease during the eclipse but transport effects mask part of the photochemical effect of eclipse on surface ozone. For Hohenpeissenberg, the box model predicted an ozone decrease, but to the eclipse, of about 2ppbv in relative agreement with the magnitude of the observed ozone decrease from the 2h moving average while at the same time it inhibits the foreseen diurnal ozone increase. However, this modeled ozone decrease during the eclipse is small compared to the diurnal ozone variability due to transport effects, and hence, transport really masks such relative small changes. The different magnitude of the surface ozone decrease between the two sites indicates mainly the role of the NO x levels. Measured and modeled NO and NO 2 concentrations at Hohenpeissenbergy during the eclipse are also compared and indicate that the partitioning of NO and NO 2 in NO x is influenced clearly from the eclipse. This is not observed at Thessaloniki due to local NO x sources. (Author)

Tropospheric Ozone Assessment Report: Database and Metrics Data of Global Surface Ozone Observations

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Martin G. Schultz

2017-10-01

Full Text Available In support of the first Tropospheric Ozone Assessment Report (TOAR a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone data products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues, which are part of this special feature. Cooperation among many data centers and individual researchers worldwide made it possible to build the world's largest collection of 'in-situ' hourly surface ozone data covering the period from 1970 to 2015. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allows for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone and they enable TOAR to perform the first, globally consistent analysis of present-day ozone concentrations and recent ozone changes with relevance to health, agriculture, and climate. Considerable effort was made to harmonize and synthesize data formats and metadata information from various networks and individual data submissions. Extensive quality control was applied to identify questionable and erroneous data, including changes in apparent instrument offsets or calibrations. Such data were excluded from TOAR data products. Limitations of 'a posteriori' data quality assurance are discussed. As a result of the work presented here, global coverage of surface ozone data for scientific analysis has been significantly extended. Yet, large gaps remain in the surface

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

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J. W. Greenslade

2017-09-01

Full Text Available Stratosphere-to-troposphere transport (STT provides an important natural source of ozone to the upper troposphere, but the characteristics of STT events in the Southern Hemisphere extratropics and their contribution to the regional tropospheric ozone budget remain poorly constrained. Here, we develop a quantitative method to identify STT events from ozonesonde profiles. Using this method we estimate the seasonality of STT events and quantify the ozone transported across the tropopause over Davis (69° S, 2006–2013, Macquarie Island (54° S, 2004–2013, and Melbourne (38° S, 2004–2013. STT seasonality is determined by two distinct methods: a Fourier bandpass filter of the vertical ozone profile and an analysis of the Brunt–Väisälä frequency. Using a bandpass filter on 7–9 years of ozone profiles from each site provides clear detection of STT events, with maximum occurrences during summer and minimum during winter for all three sites. The majority of tropospheric ozone enhancements owing to STT events occur within 2.5 and 3 km of the tropopause at Davis and Macquarie Island respectively. Events are more spread out at Melbourne, occurring frequently up to 6 km from the tropopause. The mean fraction of total tropospheric ozone attributed to STT during STT events is  ∼ 1. 0–3. 5 % at each site; however, during individual events, over 10 % of tropospheric ozone may be directly transported from the stratosphere. The cause of STTs is determined to be largely due to synoptic low-pressure frontal systems, determined using coincident ERA-Interim reanalysis meteorological data. Ozone enhancements can also be caused by biomass burning plumes transported from Africa and South America, which are apparent during austral winter and spring and are determined using satellite measurements of CO. To provide regional context for the ozonesonde observations, we use the GEOS-Chem chemical transport model, which is too coarsely

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-04-15

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Stratospheric ozone chemistry in the Antarctic: what determines the lowest ozone values reached and their recovery?

Directory of Open Access Journals (Sweden)

J.-U. Grooß

2011-12-01

Full Text Available Balloon-borne observations of ozone from the South Pole Station have been reported to reach ozone mixing ratios below the detection limit of about 10 ppbv at the 70 hPa level by late September. After reaching a minimum, ozone mixing ratios increase to above 1 ppmv on the 70 hPa level by late December. While the basic mechanisms causing the ozone hole have been known for more than 20 yr, the detailed chemical processes determining how low the local concentration can fall, and how it recovers from the minimum have not been explored so far. Both of these aspects are investigated here by analysing results from the Chemical Lagrangian Model of the Stratosphere (CLaMS. As ozone falls below about 0.5 ppmv, a balance is maintained by gas phase production of both HCl and HOCl followed by heterogeneous reaction between these two compounds in these simulations. Thereafter, a very rapid, irreversible chlorine deactivation into HCl can occur, either when ozone drops to values low enough for gas phase HCl production to exceed chlorine activation processes or when temperatures increase above the polar stratospheric cloud (PSC threshold. As a consequence, the timing and mixing ratio of the minimum ozone depends sensitively on model parameters, including the ozone initialisation. The subsequent ozone increase between October and December is linked mainly to photochemical ozone production, caused by oxygen photolysis and by the oxidation of carbon monoxide and methane.

Innate Lymphoid Cells Mediate Pulmonary Eosinophilic Inflammation, Airway Mucous Cell Metaplasia, and Type 2 Immunity in Mice Exposed to Ozone.

Science.gov (United States)

Kumagai, Kazuyoshi; Lewandowski, Ryan P; Jackson-Humbles, Daven N; Buglak, Nicholas; Li, Ning; White, Kaylin; Van Dyken, Steven J; Wagner, James G; Harkema, Jack R

2017-08-01

Exposure to elevated levels of ambient ozone in photochemical smog is associated with eosinophilic airway inflammation and nonatopic asthma in children. In the present study, we determined the role of innate lymphoid cells (ILCs) in the pathogenesis of ozone-induced nonatopic asthma by using lymphoid cell-sufficient C57BL/6 mice, ILC-sufficient Rag2 -/- mice (devoid of T and B cells), and ILC-deficient Rag2 -/- Il2rg -/- mice (depleted of all lymphoid cells including ILCs). Mice were exposed to 0 or 0.8 parts per million ozone for 1 day or 9 consecutive weekdays (4 hr/day). A single exposure to ozone caused neutrophilic inflammation, airway epithelial injury, and reparative DNA synthesis in all strains of mice, irrespective of the presence or absence of ILCs. In contrast, 9-day exposures induced eosinophilic inflammation and mucous cell metaplasia only in the lungs of ILC-sufficient mice. Repeated ozone exposures also elicited increased messenger RNA expression of transcripts associated with type 2 immunity and airway mucus production in ILC-sufficient mice. ILC-deficient mice repeatedly exposed to ozone had no pulmonary pathology or increased gene expression related to type 2 immunity. These results suggest a new paradigm for the biologic mechanisms underlying the development of a phenotype of childhood nonatopic asthma that has been linked to ambient ozone exposures.

Development and Application of Hyperspectral Infrared Ozone Retrieval Products for Operational Meteorology

Science.gov (United States)

Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

2015-01-01

cyclogenesis and hurricane force wind events. Currently, forecasters at WPC/OPC are evaluating the Air Mass RGB imagery in conjunction with the AIRS total column ozone to aid forecasting cyclogenesis and high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. To address this limitation, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air on the Air Mass RGB. This presentation describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the Air Mass RGB product for the unique forecast challenges WPC/OPC face. Additionally examples of CrIS ozone and anomaly products will be shown to further demonstrate the utility and capability of JPSS in forecasting unique events.

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

Science.gov (United States)

Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

2014-01-01

cyclogenesis and hurricane force wind events. Currently, forecasters at WPC/OPC are evaluating the Air Mass RGB imagery in conjunction with the AIRS total column ozone to aid forecasting cyclogenesis and high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. To address this limitation, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air on the Air Mass RGB. This presentation describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the Air Mass RGB product for the unique forecast challenges WPC/OPC face. Additionally examples of CrIS ozone and anomaly products will be shown to further demonstrate the utility and capability of JPSS in forecasting unique events.

C reactive protein and chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Dahl, Morten; Vestbo, Jørgen; Zacho, Jeppe

2011-01-01

It is unclear whether elevated plasma C reactive protein (CRP) is causally related to chronic obstructive pulmonary disease (COPD). The authors tested the hypothesis that genetically elevated plasma CRP causes COPD using a Mendelian randomisation design.......It is unclear whether elevated plasma C reactive protein (CRP) is causally related to chronic obstructive pulmonary disease (COPD). The authors tested the hypothesis that genetically elevated plasma CRP causes COPD using a Mendelian randomisation design....

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-09-01

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

Ozone Therapy in Dentistry

Science.gov (United States)

Domb, William C

2014-01-01

Summary The 21st century dental practice is quite dynamic. New treatment protocols and new materials are being developed at a rapid pace. Ozone dental therapy falls into the category of new treatment protocols in dentistry, yet ozone is not new at all. Ozone therapy is already a major treatment modality in Europe, South America and a number of other countries. What is provided here will not be an exhaustive scientific treatise so much as a brief general introduction into what dentists are now doing with ozone therapies and the numerous oral/systemic links that make this subject so important for physicians so that, ultimately, they may serve their patients more effectively and productively. PMID:25363268

Electroplating wastewater treatment by the combined electrochemical and ozonation methods.

Science.gov (United States)

Orescanin, Visnja; Kollar, Robert; Mikelic, Ivanka Lovrencic; Nad, Karlo

2013-01-01

This article presents a pilot-plant study of the electroplating wastewater treatment by the processes of electroreduction with iron electrode plates, and electrocoagulation/ozonation with aluminum electrode set, followed by the process of ozonation. The initial effluent was found to be highly enriched in heavy metals and to possess the elevated levels of organic contaminants. The values of Cr(VI), Fe, Ni, Cu, Zn, Pb, TOC, and COD exceeded the upper permissible limits of 63, 220.2, 1.1, 7, 131.3, 1.7, 12.3, and 11.4 times, respectively. The heavy metal removal was forced either by the coagulation/flocculation using Fe(II), Fe(III), and Al(III) ions released into the treated solution by the electrochemical corrosion of the sacrificial iron and aluminum electrodes, or the precipitation of the metal hydroxides as well as co-precipitation with iron and aluminum hydroxides. The principle organic matter destruction mechanisms were ozone oxidation and the indirect oxidation with chlorine/hypochlorite formed by the anodic oxidation of chloride already present in the wastewater. Following the combined treatment, the removal efficiencies of Cr(VI), Fe, Ni, Cu, Zn, Pb, TOC, and COD were 99.94%, 100.00%, 95.86%, 98.66%, 99.97%, 96.81%, 93.24%, and 93.43%, respectively, thus complying with the regulated values.

Flixweed is more competitive than winter wheat under ozone pollution: evidences from membrane lipid peroxidation, antioxidant enzymes and biomass.

Directory of Open Access Journals (Sweden)

Cai-Hong Li

Full Text Available To investigate the effects of ozone on winter wheat and flixweed under competition, two species were exposed to ambient, elevated and high [O3] for 30 days, planted singly or in mixculture. Eco-physiological responses were examined at different [O3] and fumigating time. Ozone reduced the contents of chlorophyll, increased the accumulation of H2O2 and malondialdehyde in both wheat and flixweed. The effects of competition on chlorophyll content of wheat emerged at elevated and high [O3], while that of flixweed emerged only at high [O3]. The increase of H2O2 and malondialdehyde of flixweed was less than that of wheat under the same condition. Antioxidant enzyme activities of wheat and flixweed were seriously depressed by perennial and serious treatment using O3. However, short-term and moderate fumigation increased the activities of SOD and POD of wheat, and CAT of flixweed. The expression levels of antioxidant enzymes related genes provided explanation for these results. Furthermore, the increase of CAT expression of flixweed was much higher than that of SOD and POD expression of wheat. Ozone and competition resulted in significant reductions in biomass and grain yield in both winter wheat and flixweed. However, the negative effects on flixweed were less than wheat. Our results demonstrated that winter wheat is more sensitive to O3 and competition than flixweed, providing valuable data for further investigation on responses of winter wheat to ozone pollution, in particular combined with species competition.

Unraveling the complex local-scale flows influencing ozone patterns in the southern Great Lakes of North America

Directory of Open Access Journals (Sweden)

I. Levy

2010-11-01

Full Text Available This study examines the complexity of various processes influencing summertime ozone levels in the southern Great Lakes region of North America. Results from the Border Air Quality and Meteorology (BAQS-Met field campaign in the summer of 2007 are examined with respect to land-lake differences and local meteorology using a large array of ground-based measurements, aircraft data, and simulation results from a high resolution (2.5 km regional air-quality model, AURAMS.

Analyses of average ozone mixing ratio from the entire BAQS-Met intensive campaign period support previous findings that ozone levels are higher over the southern Great Lakes than over the adjacent land. However, there is great heterogeneity in the spatial distribution of surface ozone over the lakes, particularly over Lake Erie during the day, with higher levels located over the southwestern end of the lake. Model results suggest that some of these increased ozone levels are due to local emission sources in large nearby urban centers. While an ozone reservoir layer is predicted by the AURAMS model over Lake Erie at night, the land-lake differences in ozone mixing ratios are most pronounced during the night in a shallow inversion layer of about 200 m above the surface. After sunrise, these differences have a limited effect on the total mass of ozone over the lakes and land during the day, though they do cause elevated ozone levels in the lake-breeze air in some locations.

The model also predicts a mean vertical circulation during the day with an updraft over Detroit-Windsor and downdraft over Lake St. Clair, which transports ozone up to 1500 m above ground and results in high ozone over the lake.

Oscillations in ground-level ozone mixing ratios were observed on several nights and at several ground monitoring sites, with amplitudes of up to 40 ppbv and time periods of 15–40 min. Several possible mechanisms for these oscillations are discussed, but a

Greater antioxidant and respiratory metabolism in field-grown soybean exposed to elevated O3 under both ambient and elevated CO2.

Science.gov (United States)

Gillespie, Kelly M; Xu, Fangxiu; Richter, Katherine T; McGrath, Justin M; Markelz, R J Cody; Ort, Donald R; Leakey, Andrew D B; Ainsworth, Elizabeth A

2012-01-01

Antioxidant metabolism is responsive to environmental conditions, and is proposed to be a key component of ozone (O(3)) tolerance in plants. Tropospheric O(3) concentration ([O(3)]) has doubled since the Industrial Revolution and will increase further if precursor emissions rise as expected over this century. Additionally, atmospheric CO(2) concentration ([CO(2)]) is increasing at an unprecedented rate and will surpass 550 ppm by 2050. This study investigated the molecular, biochemical and physiological changes in soybean exposed to elevated [O(3) ] in a background of ambient [CO(2)] and elevated [CO(2)] in the field. Previously, it has been difficult to demonstrate any link between antioxidant defences and O(3) stress under field conditions. However, this study used principle components analysis to separate variability in [O(3)] from variability in other environmental conditions (temperature, light and relative humidity). Subsequent analysis of covariance determined that soybean antioxidant metabolism increased with increasing [O(3)], in both ambient and elevated [CO(2)]. The transcriptional response was dampened at elevated [CO(2)], consistent with lower stomatal conductance and lower O(3) flux into leaves. Energetically expensive increases in antioxidant metabolism and tetrapyrrole synthesis at elevated [O(3)] were associated with greater transcript levels of enzymes involved in respiratory metabolism. © 2011 Blackwell Publishing Ltd.

The 2002 Antarctic Ozone Hole

Science.gov (United States)

Newman, P. A.; Nash, E. R.; Douglass, A. R.; Kawa, S. R.

2003-01-01

Since 1979, the ozone hole has grown from near zero size to over 24 Million km2. This area is most strongly controlled by levels of inorganic chlorine and bromine oncentrations. In addition, dynamical variations modulate the size of the ozone hole by either cooling or warming the polar vortex collar region. We will review the size observations, the size trends, and the interannual variability of the size. Using a simple trajectory model, we will demonstrate the sensitivity of the ozone hole to dynamical forcing, and we will use these observations to discuss the size of the ozone hole during the 2002 Austral spring. We will further show how the Cly decreases in the stratosphere will cause the ozone hole to decrease by 1-1.5% per year. We will also show results from a 3-D chemical transport model (CTM) that has been continuously run since 1999. These CTM results directly show how strong dynamics acts to reduce the size of the ozone hole.

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

Science.gov (United States)

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

2017-12-01

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

Intrahepatic bile duct adenoma in a patient with chronic hepatitis B accompanied by elevation of alpha-fetoprotein.

Science.gov (United States)

Ahn, Jem Ma; Paik, Yong-Han; Lee, Jun Hee; Cho, Ju Yeon; Sohn, Won; Gwak, Geum-Youn; Choi, Moon Seok; Lee, Joon Hyeok; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul

2015-12-01

A 51-year-old male patient with chronic hepatitis B was referred to our hospital due to a 1-cm liver nodule on ultrasonography. Alpha-fetoprotein (AFP) was slightly elevated. The nodule showed prolonged enhancement on dynamic liver magnetic resonance imaging and appeared as a hyperintensity on both diffusion-weighted and T2-weighted imaging. The nodule was followed up because it was small and typical findings of hepatocellular carcinoma (HCC) were not observed in the dynamic imaging investigations. However, liver contrast-enhanced ultrasonography performed 1 month later showed enhancement during the arterial phase and definite washout during the delayed phase. Also, AFP had increased to over 200 ng/mL even though AST and ALT were decreased after administering an antiviral agent. He was presumptively diagnosed as HCC and underwent liver segmentectomy. Microscopy findings of the specimen indicated bile duct adenoma. After resection, the follow-up AFP had decreased to within the normal range. This patient represents a case of bile duct adenoma with AFP elevation mimicking HCC on contrast-enhanced ultrasonography.

Intrahepatic bile duct adenoma in a patient with chronic hepatitis B accompanied by elevation of alpha-fetoprotein

Directory of Open Access Journals (Sweden)

Jem Ma Ahn

2015-12-01

Full Text Available A 51-year-old male patient with chronic hepatitis B was referred to our hospital due to a 1-cm liver nodule on ultrasonography. Alpha-fetoprotein (AFP was slightly elevated. The nodule showed prolonged enhancement on dynamic liver magnetic resonance imaging and appeared as a hyperintensity on both diffusion-weighted and T2-weighted imaging. The nodule was followed up because it was small and typical findings of hepatocellular carcinoma (HCC were not observed in the dynamic imaging investigations. However, liver contrast-enhanced ultrasonography performed 1 month later showed enhancement during the arterial phase and definite washout during the delayed phase. Also, AFP had increased to over 200 ng/mL even though AST and ALT were decreased after administering an antiviral agent. He was presumptively diagnosed as HCC and underwent liver segmentectomy. Microscopy findings of the specimen indicated bile duct adenoma. After resection, the follow-up AFP had decreased to within the normal range. This patient represents a case of bile duct adenoma with AFP elevation mimicking HCC on contrast-enhanced ultrasonography.

Investigations into regional ozone concentrations in the Bakken-Williston Basin using ARTEMIS, a mobile measurment platform.

Science.gov (United States)

Donohoue, D.; Jumes, D.; Jaglowski, J.

2017-12-01

During a campaign launched in August 2015, concentrations of ozone, nitrogen oxides, and weather conditions were measured throughout the Bakken-Williston Basin. The data was collected using a new in-situ monitoring system ARTEMIS (Atmospheric Research Trailer for Environmental Monitoring and Interactive Science). ARTEMIS is a self-sustaining trailer equipped with a solar panel and four 80 Ah batteries, which can power an instrumental suite. It provided a temporary sampling station which could be erected in five minutes. During this campaign we collected data for one hour at sites throughout North Dakota and Montana. Preliminary results from this data suggests that near active mining or methane flaring regions ozone concentrations appear to be elevated from the background.

Gender, obesity and repeated elevation of C-reactive protein: data from the CARDIA cohort.

Directory of Open Access Journals (Sweden)

Shinya Ishii

Full Text Available C-reactive Protein (CRP measurements above 10 mg/L have been conventionally treated as acute inflammation and excluded from epidemiologic studies of chronic inflammation. However, recent evidence suggest that such CRP elevations can be seen even with chronic inflammation. The authors assessed 3,300 participants in The Coronary Artery Risk Development in Young Adults study, who had two or more CRP measurements between 1992/3 and 2005/6 to a investigate characteristics associated with repeated CRP elevation above 10 mg/L; b identify subgroups at high risk of repeated elevation; and c investigate the effect of different CRP thresholds on the probability of an elevation being one-time rather than repeated. 225 participants (6.8% had one-time and 103 (3.1% had repeated CRP elevation above 10 mg/L. Repeated elevation was associated with obesity, female gender, low income, and sex hormone use. The probability of an elevation above 10 mg/L being one-time rather than repeated was lowest (51% in women with body mass index above 31 kg/m(2, compared to 82% in others. These findings suggest that CRP elevations above 10 mg/L in obese women are likely to be from chronic rather than acute inflammation, and that CRP thresholds above 10 mg/L may be warranted to distinguish acute from chronic inflammation in obese women.

Transport of nitrogen oxides, carbon monoxide and ozone to the Alpine Global Atmosphere Watch stations Jungfraujoch (Switzerland), Zugspitze and Hohenpeissenberg (Germany), Sonnblick (Austria) and Mt. Krvavec (Slovenia)

Science.gov (United States)

Kaiser, August; Scheifinger, Helfried; Spangl, Wolfgang; Weiss, Andrea; Gilge, Stefan; Fricke, Wolfgang; Ries, Ludwig; Cemas, Danijel; Jesenovec, Brigita

The Alpine stations Zugspitze, Hohenpeissenberg, Sonnblick, Jungfraujoch and Mt. Krvavec contribute to the Global Atmosphere Watch Programme (GAW) of the World Meteorological Organization (WMO). The aim of GAW is the surveillance of the large-scale chemical composition of the atmosphere. Thus, the detection of air pollutant transport from regional sources is of particular interest. In this paper, the origin of NO x (measured with a photo-converter), CO and O 3 at the four Alpine GAW stations is studied by trajectory residence time statistics. Although these methods originated during the early 1980s, no comprehensive study of different atmospheric trace gases measured simultaneously at several background observatories in the Alps was conducted up to present. The main NO x source regions detected by the trajectory statistics are the northwest of Europe and the region covering East Germany, Czech Republic and southeast Poland, whereas the main CO source areas are the central, north eastern and eastern parts of Europe with some gradient from low to high latitudes. Subsiding air masses from west and southwest are relatively poor in NO x and CO. The statistics for ozone show strong seasonal effects. Near ground air masses are poor in ozone in winter but rich in ozone in summer. The main source for high ozone concentration in winter is air masses that subside from higher elevations, often enhanced by foehn effects at Hohenpeissenberg. During summer, the Mediterranean constitutes an important additional source for high ozone concentrations. Especially during winter, large differences between Hohenpeissenberg and the higher elevated stations are found. Hohenpeissenberg is frequently within the inversion, whereas the higher elevated stations are above the inversion. Jungfraujoch is the only station where the statistics detect an influence of air rich in CO and NO x from the Po Basin.

Observations of nitryl chloride and modeling its source and effect on ozone in the planetary boundary layer of southern China

Science.gov (United States)

Wang, Tao; Tham, Yee Jun; Xue, Likun; Li, Qinyi; Zha, Qiaozhi; Wang, Zhe; Poon, Steven C. N.; Dubé, William P.; Blake, Donald R.; Louie, Peter K. K.; Luk, Connie W. Y.; Tsui, Wilson; Brown, Steven S.

2016-03-01

Nitryl chloride (ClNO2) plays potentially important roles in atmospheric chemistry, but its abundance and effect are not fully understood due to the small number of ambient observations of ClNO2 to date. In late autumn 2013, ClNO2 was measured with a chemical ionization mass spectrometer (CIMS) at a mountain top (957 m above sea level) in Hong Kong. During 12 nights with continuous CIMS data, elevated mixing ratios of ClNO2 (>400 parts per trillion by volume) or its precursor N2O5 (>1000 pptv) were observed on six nights, with the highest ever reported ClNO2 (4.7 ppbv, 1 min average) and N2O5 (7.7 ppbv, 1 min average) in one case. Backward particle dispersion calculations driven by winds simulated with a mesoscale meteorological model show that the ClNO2/N2O5-laden air at the high-elevation site was due to transport of urban/industrial pollution north of the site. The highest ClNO2/N2O5 case was observed in a later period of the night and was characterized with extensively processed air and with the presence of nonoceanic chloride. A chemical box model with detailed chlorine chemistry was used to assess the possible impact of the ClNO2 in the well-processed regional plume on next day ozone, as the air mass continued to downwind locations. The results show that the ClNO2 could enhance ozone by 5-16% at the ozone peak or 11-41% daytime ozone production in the following day. This study highlights varying importance of the ClNO2 chemistry in polluted environments and the need to consider this process in photochemical models for prediction of ground-level ozone and haze.

Ozone depletion following future volcanic eruptions

Science.gov (United States)

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

2017-07-01

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

Ozone-depleting Substances (ODS)

Data.gov (United States)

U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

Ozone sensitivity to varying greenhouse gases and ozone-depleting substances in CCMI-1 simulations

Directory of Open Access Journals (Sweden)

O. Morgenstern

2018-01-01

Full Text Available Ozone fields simulated for the first phase of the Chemistry-Climate Model Initiative (CCMI-1 will be used as forcing data in the 6th Coupled Model Intercomparison Project. Here we assess, using reference and sensitivity simulations produced for CCMI-1, the suitability of CCMI-1 model results for this process, investigating the degree of consistency amongst models regarding their responses to variations in individual forcings. We consider the influences of methane, nitrous oxide, a combination of chlorinated or brominated ozone-depleting substances, and a combination of carbon dioxide and other greenhouse gases. We find varying degrees of consistency in the models' responses in ozone to these individual forcings, including some considerable disagreement. In particular, the response of total-column ozone to these forcings is less consistent across the multi-model ensemble than profile comparisons. We analyse how stratospheric age of air, a commonly used diagnostic of stratospheric transport, responds to the forcings. For this diagnostic we find some salient differences in model behaviour, which may explain some of the findings for ozone. The findings imply that the ozone fields derived from CCMI-1 are subject to considerable uncertainties regarding the impacts of these anthropogenic forcings. We offer some thoughts on how to best approach the problem of generating a consensus ozone database from a multi-model ensemble such as CCMI-1.

Ozone Sensitivity to Varying Greenhouse Gases and Ozone-Depleting Substances in CCMI-1 Simulations

Science.gov (United States)

Morgenstern, Olaf; Stone, Kane A.; Schofield, Robyn; Akiyoshi, Hideharu; Yamashita, Yousuke; Kinnison, Douglas E.; Garcia, Rolando R.; Sudo, Kengo; Plummer, David A.; Scinocca, John;

Elevated human chorionic gonadotropin levels in patients with chronic kidney disease: Case series and review of literature

Directory of Open Access Journals (Sweden)

S Soni

2013-01-01

Full Text Available Women are often subjected to serum human chorionic gonadotropin (HCG testing prior to diagnostic and therapeutic interventions. A positive result leads to further testing to rule out pregnancy and avoid possible fetal teratogenicity. The impact of chronic kidney disease (CKD on HCG testing has not been studied. We report a series of 5 women out of 62 with CKD, who had a positive HCG test on routine pre-transplant screening at a single transplant center. We analyzed their case records retrospectively. Despite aggressive investigation, their elevated HCG levels remained unexplained. The positive test contributed to delays in transplantation and increased overall cost of treatment.

Caffeine degradation in water by gamma irradiation, ozonation and ozonation/gamma irradiation

Directory of Open Access Journals (Sweden)

Torun Murat

2014-03-01

Full Text Available Aqueous solutions of caffeine were treated with ozone and gamma irradiation. The amounts of remaining caffeine were determined after solid phase extraction as a function of absorbed dose and ozonation time. In addition to this, some important parameters such as inorganic ions, chemical oxygen demand (COD dissolved oxygen and total acidity changes were followed. Caffeine (50 ppm is found to be completely decomposed at 3.0 kGy and 1.2 kGy doses in the absence of H2O2 and in 1.20 mM H2O2 solutions, respectively. In the case of gamma irradiation after ozonation, 50 ppm caffeine was removed at 0.2 kGy when the solution was ozonized for 100 s at a rate of 10 g O3 h-1 in 400 mL 50 ppm paracetamol solution.

ROCOZ-A (improved rocket launched ozone sensor) for middle atmosphere ozone measurements

International Nuclear Information System (INIS)

Lee, H.S.; Parsons, C.L.

1987-01-01

An improved interference filter based ultraviolet photometer (ROCOZ-A) for measuring stratospheric ozone is discussed. The payload is launched aboard a Super-Loki to a typical apogee of 70 km. The instrument measures the solar ultraviolet irradiance as it descends on a parachute. The total cumulative ozone is then calculated based on the Beer-Lambert law. The cumulative ozone precision measured in this way is 2.0% to 2.5% over an altitude range of 20 and 55 km. Results of the intercomparison with the SBUV overpass data and ROCOZ-A data are also discussed

Long range transport of CO and ozone from source regions in Asia

Energy Technology Data Exchange (ETDEWEB)

Jaffe, D.; Mahura, A. [Univ. of Alaska, Fairbanks, AK (United States)]|[Institute of Northern Ecological Problems, Moscow (Russian Federation); Novelli, P. [Univ. of Colorado, Boulder, CO (United States); Merrill, J. [Univ. of Rhode Island, Narraganset, RI (United States)

1996-12-31

Based on current understanding of the atmosphere, CO and photochemically produced ozone can be transported thousands of kilometers prior to being removed. Emissions from Asia have a possible impact on the CO and ozone concentrations over the U.S. west coast following transport across the Pacific Ocean. If this is correct, then there are implications for ozone control strategies in the downwind region. Evidence includes: (1) Global 3D chemical transport models indicating a monthly mean enhancement of 10-20% on the US west coast for both CO and ozone during winter-spring due to emissions from Asia; and (2) CO and O{sub 3} data from several Pacific sites which demonstrate that Asian pollutants can be transported great distances. The weekly flask data clearly define a CO seasonal cycle. In the present analysis we use a locally weighted smoothing technique to identify individual data outliers from the smoothed seasonal cycle. We hypothesize that these outliers represent periods when continental emissions influenced the atmospheric mixing ratios at these locations. Using isentropic back trajectories we try to identify a possible source region or pathway for each event and present a distribution of the trajectory types for the events. For the events at Midway, Mauna Loa, Guam and Shemya, we are able to identify a source region for elevated CO in 82, 72, 65 and 50% of the events, respectively. At Mauna Loa and Midway a majority of the events occur during spring and are mostly associated with transport from Asia. These events bring the highest CO mixing ratios observed at any time during the year to these sites, with CO enhancements up to 46 ppb. For Mauna Loa, a small number of events during summer are due to transport from North and Central America. In-situ ozone from Mauna Loa also demonstrates an impact from Asian emissions.

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

Directory of Open Access Journals (Sweden)

Selva eRivas - Arancibia

2015-05-01

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

Ozone adsorption on carbon nanoparticles

Science.gov (United States)

Chassard, Guillaume; Gosselin, Sylvie; Visez, Nicolas; Petitprez, Denis

2014-05-01

Carbonaceous particles produced by incomplete combustion or thermal decomposition of hydrocarbons are ubiquitous in the atmosphere. On these particles are adsorbed hundreds of chemical species. Those of great concern to health are polycyclic aromatic hydrocarbons (PAHs). During atmospheric transport, particulate PAHs react with gaseous oxidants. The induced chemical transformations may change toxicity and hygroscopicity of these potentially inhalable particles. The interaction between ozone and carbon particles has been extensively investigated in literature. However ozone adsorption and surface reaction mechanisms are still ambiguous. Some studies described a fast catalytic decomposition of ozone initiated by an atomic oxygen chemisorption followed by a molecular oxygen release [1-3]. Others suggested a reversible ozone adsorption according to Langmuir-type behaviour [4,5]. The aim of this present study is a better understanding of ozone interaction with carbon surfaces. An aerosol of carbon nanoparticles was generated by flowing synthetic air in a glass tube containing pure carbon (primary particles studied. Accordingly to literature, it has been observed that the number of gas-phase ozone molecules lost per unit particle surface area tends towards a plateau for high ozone concentration suggesting a reversible ozone adsorption according to a Langmuir mechanism. We calculated the initial reaction probability between O3 and carbon particles.An initial uptake coefficient of 1.10-4 was obtained. Similar experiments were realized by selecting the particles size with a differential mobility analyser. We observed a strong size-dependent increase in reactivity with the decrease of particles size. This result is relevant for the health issues. Indeed the smallest particles are most likely to penetrate deep into the lungs. Competitive reactions between ozone and other species like H2O or atomic oxygen were also considered. Oxygen atoms were generated by photolysis of O3

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers

Energy Technology Data Exchange (ETDEWEB)

Burkey, Kent O. [Plant Science Research Unit, USDA-ARS and North Carolina State University, 3127 Ligon Street, Raleigh, NC 27607 (United States)]. E-mail: koburkey@unity.ncsu.edu; Neufeld, Howard S. [Appalachian State University, Boone, NC (United States); Souza, Lara [Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN (United States); Chappelka, Arthur H. [Auburn University, Auburn, AL (United States); Davison, Alan W. [University of Newcastle, Newcastle, England (United Kingdom)

2006-10-15

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 {mu}mol g{sup -1} fresh weight) than crown-beard (2-4 {mu}mol g{sup -1} fresh weight) or cutleaf coneflower (0.5-2 {mu}mol g{sup -1} fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g{sup -1} fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity. - Wildflower species exhibit differences in ascorbic acid content and redox status that affect ozone sensitivity.

Tropospheric ozone. Formation, properties, effects. Expert opinion; Ozon in der Troposphaere. Bildung, Eigenschaften, Wirkungen. Gutachten

Energy Technology Data Exchange (ETDEWEB)

Elstner, E.F. [Technische Univ. Muenchen (Germany). Lehrstuhl fuer Phytopathologie

1996-06-01

The formation and dispersion of tropospheric ozone are discussed only marginally in this expert opinion; the key interest is in the effects of ground level ozone on plants, animals, and humans. The expert opinion is based on an analysis of the available scientific publications. (orig./MG) [Deutsch] Das Gutachten nimmt nur am Rande die Problematik der Bildung und Ausbreitung von troposphaerischen Ozon auf; Im Mittelpunkt steht die Auseinandersetzung mit den Wirkungen des bodennahen Ozons auf Pflanze, Tier und Mensch. Das Gutachten basiert auf einer Analyse der zugaenglichen wissenschaftlichen Arbeiten. (orig./MG)

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

Science.gov (United States)

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

1983-10-01

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

Issues in Stratospheric Ozone Depletion.

Science.gov (United States)

Lloyd, Steven Andrew

Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

Two-phase ozonation of chlorinated organics

International Nuclear Information System (INIS)

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

1995-01-01

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

Ozone bioindicator sampling and estimation

Science.gov (United States)

Gretchen C, Smith; William D. Smith; John W. Coulston

2007-01-01

Ozone is an important forest stressor that has been measured at known phytotoxic levels at forest locations across the United States. The percent forest exhibiting negative impacts from ozone air pollution is one of the Montreal Process indicators of forest health and vitality. The ozone bioindicator data of the U.S. Forest Service Forest Inventory and Analysis Program...

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

DEFF Research Database (Denmark)

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

2006-01-01

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

Serum lipid and lipoprotein concentrations following exposure to ozone

Energy Technology Data Exchange (ETDEWEB)

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

1984-07-01

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

Results of photochemical modeling sensitivity analyses in the Lake Michigan region: Current status of Lake Michigan Ozone Control Program (LMOP) modeling

Energy Technology Data Exchange (ETDEWEB)

Dolwick, P.D. [Lake Michigan Air Directors Consortium, Des Plaines, IL (United States); Kaleel, R.J. [Illinois Environmental Protection Agency, Springfield, IL (United States); Majewski, M.A. [Wisconsin Dept. of Natural Resources, Madison, WI (United States)

1994-12-31

The four states that border Lake Michigan are cooperatively applying a state-of-the-art nested photochemical grid model to assess the effects of potential emission control strategies on reducing elevated tropospheric ozone concentrations in the region to levels below the national ambient air quality standard. In order to provide an extensive database to support the application of the photochemical model, a substantial data collection effort known as the Lake Michigan Ozone Study (LMOS) was completed during the summer of 1991. The Lake Michigan Ozone Control Program (LMOP) was established by the States of Illinois, Wisconsin, Michigan, and Indiana to carry out the application of the modeling system developed from the LMOS, in terms of developing the attainment demonstrations required from this area by the Clean Air Act Amendments of 1990.

Third year effects of cloudwater and ozone on red spruce seedlings

International Nuclear Information System (INIS)

Pier, P.A.; Thornton, F.C.; McDuffie, C. Jr.

1991-01-01

The reduction in growth of high elevation red spruce in the eastern US has been attributed in part to greater exposure to atmospheric pollution which occurs at high elevation. The authors objective was to evaluate the impact of ambient ozone and cloudwater deposition on the growth of red spruce seedlings at a high elevation site. Potted native and Phyton-grown (Phyton Technologies) red spruce seedlings were exposed in open-top field chambers at Whitetop Mountain, Virginia (elevation 1,680) for the third season to treatments of: (1) exclusion of clouds and 50% reduction in ambient O 3 (COE), (2) O 3 with clouds excluded (CO), (3) exposure to clouds and O 3 , as control chambers (CC), and (4) open plots (AA). Plant biomass components and diameter increment growth for both seedling types were not affected by treatments. Photosynthesis was not enhanced by removal of cloudwater and O 3 . Respiration (R d ) generally was not affected by treatments; however, R d in native seedling needles of previous year and two-year previous growth was significantly greater in CC than CO and COE on several sampling dates, indicating that cloudwater and O 3 may be causing higher R d

Degradation of 4-chlorophenol by ozonation, γ radiation as well as ozonation combined with γ radiation

International Nuclear Information System (INIS)

Hu, J.; Wang, J.L.

2005-01-01

The radiolysis of aqueous 4-chlorophenol (4-CP) by gamma radiation in the presence of air and ozone was investigated. The 4-CP degradation, release of chloride ion, UV absorption spectrum, total organic carbon (TOC) and adsorbable organic halogens (AOX) was measured. Under the conditions of synergistic effect of ozone and radiation a complete degradation of 100 mg/L 4-CP was obtained at a dose of 6 kGy, without ozone the 4-chlorophenol was completely decomposed at 15 kGy. The total organic carbon (TOC) was reduced by 26% when ionizing radiation (at 15 kGy) combined with ozonation, and by 17% without ozone, respectively. Analysis of intermediate products resulting from synergistic effect of ozone and radiation of 4-CP was performed by using the GC/MS method. Some primary influencing factors such as irradiation time and initial 4-CP concentration were also discussed. The results showed that the degradation of 4-chlorophenol could described by first-order reaction kinetic model. There is potential for combination of irradiation with ozonation, which can remarkably reduce the irradiation dose increase the degradation efficiency of 4-CP.

Sterilization of Microorganisms by Ozone and Ultrasound

Science.gov (United States)

Krasnyj, V. V.; Klosovskij, A. V.; Panasko, T. A.; Shvets, O. M.; Semenova, O. T.; Taran, V. S.; Tereshin, V. I.

2008-03-01

The results of recent experimental methods of sterilization of microorganisms with the use of ozone and ultrasound are presented. The main aim was to optimize the process of sterilization in water solution taking into account the ozone concentration, the power of ultrasonic emitter and the temperature of water. In the present work, the ultrasonic cavitation with simultaneous ozone generation has been used. The high ozone concentration in water solution was achieved by two-barrier glow discharge generated at atmospheric pressure and a cooling thermo-electric module. Such a sterilizer consists of ozone generator in a shape of flat electrodes covered with dielectric material and a high-voltage pulsed power supply of 250 W. The sterilization camera was equipped with ultrasonic source operated at 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. The ozone concentration in the aqueous solution was 10 mg/1, whereas the ozone concentration at the output of ozone generator was 30 mg/1. The complete inactivation of spores took 15 min. Selection of the temperature of water, the ozone concentrations and ultrasonic power allowed to determine the time necessary for destroying the row of microorganisms.

The behaviour of stratospheric and upper tropospheric ozone in high and mid latitudes; the role of ozone as a climate gas

Energy Technology Data Exchange (ETDEWEB)

Kyroe, M; Rummukainen, M; Kivi, R; Turunen, T; Karhu, J [Finnish Meteorological Inst., Sodankylae (Finland); Taalas, P [Finnish Meteorological Inst., Helsinki (Finland)

1997-12-31

During the past few years, the dual role that ozone plays in climate change has been becoming increasingly obvious. First, continuous thinning of the ozone layer has been evident, even in the high and middle latitudes in the northern hemisphere. Secondly, ozone is also a greenhouse gas, affecting radiative transfer. Increases in tropospheric ozone have a positive forcing, whereas decreases in stratospheric ozone cause a negative forcing. During the last six years, measurements on total ozone and the vertical distribution of ozone have been performed at the Sodankylae Observatory. At Jokioinen Observatory, measurements on total ozone have been performed since 1990 and measurements on the vertical distribution of ozone since 1993. The overall project has focused on extending the national data series on total ozone and the vertical distribution of ozone. At the same time, the study has contributed to the study of interannual variability of the ozone layer. This SILMU project took part in the large-scale research activities, in addition to performing national studies. The results confirm that there has been fast chemical ozone destruction in the high latitudes in the northern hemisphere. This was particularly evident in the last two winters, 1994/95 and 1995/96. The new data also allows better trend analyses to be made on ozone in high and mid latitudes

The behaviour of stratospheric and upper tropospheric ozone in high and mid latitudes; the role of ozone as a climate gas

Energy Technology Data Exchange (ETDEWEB)

Kyroe, M.; Rummukainen, M.; Kivi, R.; Turunen, T.; Karhu, J. [Finnish Meteorological Inst., Sodankylae (Finland); Taalas, P. [Finnish Meteorological Inst., Helsinki (Finland)

1996-12-31

During the past few years, the dual role that ozone plays in climate change has been becoming increasingly obvious. First, continuous thinning of the ozone layer has been evident, even in the high and middle latitudes in the northern hemisphere. Secondly, ozone is also a greenhouse gas, affecting radiative transfer. Increases in tropospheric ozone have a positive forcing, whereas decreases in stratospheric ozone cause a negative forcing. During the last six years, measurements on total ozone and the vertical distribution of ozone have been performed at the Sodankylae Observatory. At Jokioinen Observatory, measurements on total ozone have been performed since 1990 and measurements on the vertical distribution of ozone since 1993. The overall project has focused on extending the national data series on total ozone and the vertical distribution of ozone. At the same time, the study has contributed to the study of interannual variability of the ozone layer. This SILMU project took part in the large-scale research activities, in addition to performing national studies. The results confirm that there has been fast chemical ozone destruction in the high latitudes in the northern hemisphere. This was particularly evident in the last two winters, 1994/95 and 1995/96. The new data also allows better trend analyses to be made on ozone in high and mid latitudes

Automatic programmable air ozonizer

International Nuclear Information System (INIS)

Gubarev, S.P.; Klosovsky, A.V.; Opaleva, G.P.; Taran, V.S.; Zolototrubova, M.I.

2015-01-01

In this paper we describe a compact, economical, easy to manage auto air ozonator developed at the Institute of Plasma Physics of the NSC KIPT. It is designed for sanitation, disinfection of premises and cleaning the air from foreign odors. A distinctive feature of the developed device is the generation of a given concentration of ozone, approximately 0.7 maximum allowable concentration (MAC), and automatic maintenance of a specified level. This allows people to be inside the processed premises during operation. The microprocessor controller to control the operation of the ozonator was developed

Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

Science.gov (United States)

Asko Noormets; Olevi Kull; Anu Sober; Mark E. Kubiske; David F. Karnosky

2010-01-01

The effect of elevated CO2 and O3 on apparent quantum yield (ø), maximum photosynthesis (Pmax), carboxylation efficiency (Vcmax) and electron transport capacity (Jmax) at different canopy locations was studied in two aspen (Populus...

Relative impacts of worldwide tropospheric ozone changes and regional emission modifications on European surface-ozone levels

International Nuclear Information System (INIS)

Szopa, S.; Hauglustaine, D.A.

2007-01-01

Multi-scale models were applied to assess the surface ozone changes in 2030. Several emission scenarios are considered, ranging from (a) a pessimistic anthropogenic emission increase to (b) an optimistic decrease of emissions, and including (c) a realistic scenario that assumes the implementation of control legislations [CLE]. The two extreme scenarios lead respectively to homogeneous global increase and decrease of surface ozone, whereas low and inhomogeneous changes associated with a slight global increase of ozone are found for the CLE scenario. Over western Europe, for the CLE scenario, the benefit of European emission reduction is significantly counterbalanced by increasing global ozone levels. Considering warmer conditions over Europe and future emission modifications, the human health exposure to surface ozone is found to be significantly worsened. (authors)

Measurements of ozone and its precursors in Beijing in summer

Science.gov (United States)

Lee, J. D.; Squires, F. A.; Dunmore, R.; Hamilton, J. F.; Hopkins, J. R.; Rickard, A. R.

2017-12-01

Over the past few years there have been substantial reductions in emission of primary pollutants (e.g. PM, NOx) in Beijing. However, levels of ozone (O3), which is produced from VOCs and NOxin the presence of sunlight, frequently break recommended exposure limits in Beijing and other large conurbations in China. In fact, it is suggested that ozone is likely to become the major air pollutant effecting human health in Beijing over the next 5-10 years. For 5 weeks in May and June 2017 O3 was measured, along with NOx, CO and a large range of VOCs (C2 - C13) at the Institute of Atmospheric Physics of the Chinese Academy of Sciences site, close to the 4th ring road in central Beijing. Elevated levels of O3 were regularly observed, with maximum concentrations of 180 ppbv. On 75% of days during this period, O3 breached the recommended WHO 8 hour exposure limit of 60 ppbv. Data will be presented showing the effect of different levels of precursor species and photolysis rates on O3. The peak concentration of O3 on each day seemed to have little correlation with NOx. Typically NO concentrations were elevated during the morning but often decreased to below 35oC meaning biogenic emissions also influenced the chemistry at the site, with several ppbv of isoprene measured during the afternoons. The importance of different VOCs for in-situ O3 formation is investigated using a simple steady state analysis of OH reactivity, along with a more detailed analysis using the Master Chemical Mechanism.

Mesoscale circulation systems and ozone concentrations during ESCOMPTE: a case study from IOP 2b

Science.gov (United States)

Kalthoff, N.; Kottmeier, C.; Thürauf, J.; Corsmeier, U.; Saїd, F.; Fréjafon, E.; Perros, P. E.

2005-03-01

The main objective of 'Expérience sur Site pour COntraindre les Modèles de Pollution atmosphérique et de Transport d'Emissions' (ESCOMPTE) is to generate a relevant data set for testing and evaluating mesoscale chemistry-transport models (CTMs). During ESCOMPTE, measurements have been performed at numerous surface stations, by radars and lidars, and several aircraft in the planetary boundary layer. The data from these different sources have been merged to obtain a consistent description of the spatial distribution of wind, temperature, humidity, and ozone for the photosmog episode on June 25, 2001 (IOP 2b). On this day, moderate synoptic winds favour the evolution of different mesoscale circulation systems. During daytime, the sea breeze penetrates towards the north in the Rhône valley. As the winds above the sea breeze layer come from the east, polluted air from the metropolitan area of Marseille leads to an increase of ozone at elevated layers above the convective boundary layer (CBL). At the mountainous station of Luberon about 55 km north of Marseille around noon, when the CBL top surpasses the height of the mountain summit, polluted air with ozone concentrations of about 120 ppbv arrived from southerly directions, thus indicating the passage of the city plume of Marseille. At Cadarache and Vinon in the Durance valley, about 60 km inland, the ozone maximum at the surface and at flight level 920 m MSL appears between 14 and 15 UTC. At this time, southwesterly valley winds prevail in the valley, while southerly winds occur above. This finding highlights the height-dependent advection of ozone due to interacting mesoscale circulation systems. These dynamical processes need to be represented adequately in CTMs to deliver a realistic description of the ozone concentration fields.

The holes in the ozone scare

Energy Technology Data Exchange (ETDEWEB)

Maduro, R.; Schauerhamer, R.

1992-05-01

For the authors, the ozone hole is more politic than scientific, and is caused by anthropogenic CFC, the ozone concentration reduction measured in the antarctic stratosphere is a natural phenomena: ozone destruction by chlorides and bromides coming from volcanos and oceans. The ozone hole was discovered in 1956 and not in 1985. For the greenhouse effect, the CO[sub 2] part is very small in comparison with the atmospheric water vapour part. (A.B.). refs., figs., tabs.

CHARACTERIZATION OF OZONE EMISSIONS FROM AIR CLEANERS EQUIPPED WITH OZONE GENERATORS AND SENSOR AND FEEDBACK CONTROL CIRCUITRY

Science.gov (United States)

The paper give results of a characterization of ozone emissions from air cleaners equipped with ozone generators and sensor and feedback control circuitry. Ozone emission rates of several consumer appliances, marketed as indoor air treatment or air purification systems, were det...

Tropospheric ozone seasonal and long-term variability as seen by lidar and surface measurements at the JPL-Table Mountain Facility, California

Directory of Open Access Journals (Sweden)

M. J. Granados-Muñoz

2016-07-01

Full Text Available A combined surface and tropospheric ozone climatology and interannual variability study was performed for the first time using co-located ozone photometer measurements (2013–2015 and tropospheric ozone differential absorption lidar measurements (2000–2015 at the Jet Propulsion Laboratory Table Mountain Facility (TMF; elev. 2285 m, in California. The surface time series were investigated both in terms of seasonal and diurnal variability. The observed surface ozone is typical of high-elevation remote sites, with small amplitude of the seasonal and diurnal cycles, and high ozone values, compared to neighboring lower altitude stations representative of urban boundary layer conditions. The ozone mixing ratio ranges from 45 ppbv in the winter morning hours to 65 ppbv in the spring and summer afternoon hours. At the time of the lidar measurements (early night, the seasonal cycle observed at the surface is similar to that observed by lidar between 3.5 and 9 km. Above 9 km, the local tropopause height variation with time and season impacts significantly the ozone lidar observations. The frequent tropopause folds found in the vicinity of TMF (27 % of the time, mostly in winter and spring produce a dual-peak vertical structure in ozone within the fold layer, characterized by higher-than-average values in the bottom half of the fold (12–14 km, and lower-than-averaged values in the top half of the fold (14–18 km. This structure is consistent with the expected origin of the air parcels within the fold, i.e., mid-latitude stratospheric air folding down below the upper tropospheric sub-tropical air. The influence of the tropopause folds extends down to 5 km, increasing the ozone content in the troposphere. No significant signature of interannual variability could be observed on the 2000–2015 de-seasonalized lidar time series, with only a statistically non-significant positive anomaly during the years 2003–2007. Our trend analysis

Effects of ozone and ozone/peroxide on trace organic contaminants and NDMA in drinking water and water reuse applications.

Science.gov (United States)

Pisarenko, Aleksey N; Stanford, Benjamin D; Yan, Dongxu; Gerrity, Daniel; Snyder, Shane A

2012-02-01

An ozone and ozone/peroxide oxidation process was evaluated at pilot scale for trace organic contaminant (TOrC) mitigation and NDMA formation in both drinking water and water reuse applications. A reverse osmosis (RO) pilot was also evaluated as part of the water reuse treatment train. Ozone/peroxide showed lower electrical energy per order of removal (EEO) values for TOrCs in surface water treatment, but the addition of hydrogen peroxide increased EEO values during wastewater treatment. TOrC oxidation was correlated to changes in UV(254) absorbance and fluorescence offering a surrogate model for predicting contaminant removal. A decrease in N-nitrosodimethylamine (NDMA) formation potential (after chloramination) was observed after treatment with ozone and ozone/peroxide. However, during spiking experiments with surface water, ozone/peroxide achieved limited destruction of NDMA, while in wastewaters net direct formation of NDMA of 6-33 ng/L was observed after either ozone or ozone/peroxide treatment. Once formed during ozonation, NDMA passed through the subsequent RO membranes, which highlights the significance of the potential for direct NDMA formation during oxidation in reuse applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

Correlative studies of satellite ozone sensor measurements

International Nuclear Information System (INIS)

Lovill, J.E.; Ellis, J.S.

1983-01-01

Comparisons are made between total ozone measurements made by four satellite ozone sensors (TOMS, SBUV, TOVS and MFR). The comparisons were made during July 1979 when all sensors were operating simultaneously. The TOMS and SBUV sensors were observed to measure less total ozone than the MFR sensor, 10 and 15 Dobson units (DU) respectively. The MFR and TOMS sensors measured less ozone than the TOVS sensor, 19 an 28 DU, respectively. Latitudinal variability of the total ozone comparisons is discussed

Ozone distribution and phytotoxic potential in mixed conifer forests of the San Bernardino Mountains, southern California

International Nuclear Information System (INIS)

Bytnerowicz, Andrzej; Arbaugh, Michael; Schilling, Susan; Fraczek, Witold; Alexander, Diane

2008-01-01

In the San Bernardino Mountains of southern California, ozone (O 3 ) concentrations have been elevated since the 1950s with peaks reaching 600 ppb and summer seasonal averages >100 ppb in the 1970s. During that period increased mortality of ponderosa and Jeffrey pines occurred. Between the late 1970s and late1990s, O 3 concentrations decreased with peaks ∼180 ppb and ∼60 ppb seasonal averages. However, since the late 1990s concentrations have not changed. Monitoring during summers of 2002-2006 showed that O 3 concentrations (2-week averages) for individual years were much higher in western sites (58-69 ppb) than eastern sites (44-50 ppb). Potential O 3 phytotoxicity measured as various exposure indices was very high, reaching SUM00 - 173.5 ppm h, SUM60 - 112.7 ppm h, W126 - 98.3 ppm h, and AOT40 - 75 ppm h, representing the highest values reported for mountain areas in North America and Europe. - Although peak ozone concentrations have greatly decreased in the San Bernardino Mountains, very high ozone phytotoxic potential remains

The Ecophysiology Of A Pinus Ponderosa Ecosystem Exposed To High Tropospheric Ozone: Implications For Stomatal And Non-Stomatal Ozone Fluxes

Science.gov (United States)

Fares, S.; McKay, M.; Goldstein, A.

2008-12-01

Ecosystems remove ozone from the troposphere through both stomatal and non-stomatal deposition. The portion of ozone taken up through stomata has an oxidative effect causing damage. We used a multi-year dataset to assess the physiological controls over ozone deposition. Environmental parameters, CO2 and ozone fluxes were measured continuously from January 2001 to December 2006 above a ponderosa pine plantation near Blodgett Forest, Georgetown, California. We studied the dynamic of NEE (Net Ecosystem Exchange, -838 g C m-2 yr-1) and water evapotranspiration on an annual and daily basis. These processes are tightly coupled to stomatal aperture which also controlled ozone fluxes. High levels of ozone concentrations (~ 100 ppb) were observed during the spring-summer period, with corresponding high levels of ozone fluxes (~ 30 μmol m-2 h-1). During the summer season, a large portion of the total ozone flux was due to non-stomatal processes, and we propose that a plant physiological control, releasing BVOC (Biogenic Volatile Organic Compounds), is mainly responsible. We analyzed the correlations of common ozone exposure metrics based on accumulation of concentrations (AOT40 and SUM0) with ozone fluxes (total, stomatal and non-stomatal). Stomatal flux showed poorer correlation with ozone concentrations than non-stomatal flux during summer and fall seasons, which largely corresponded to the growing period. We therefore suggest that AOT40 and SUM0 are poor predictors of ozone damage and that a physiologically based metric would be more effective.

The contrasting responses of soil microorganisms in two rice cultivars to elevated ground-level ozone

International Nuclear Information System (INIS)

Feng, Youzhi; Yu, Yongjie; Tang, Haoye; Zu, Qianhui; Zhu, Jianguo; Lin, Xiangui

2015-01-01

Although elevated ground-level O 3 has a species–specific impact on plant growth, the differences in soil biota responses to O 3 pollution among rice cultivars are rarely reported. Using O 3 Free-Air Concentration Enrichment, the responses of the rhizospheric bacterial communities in the O 3 -tolerant (YD6) and the O 3 -sensitive (IIY084) rice cultivars to O 3 pollution and their differences were assessed by pyrosequencing at rice tillering and anthesis stages. Elevated ground-level O 3 negatively influenced the bacterial community in cultivar YD6 at both rice growth stages by decreasing the bacterial phylogenetic diversities and response ratios. In contrast, in cultivar IIY084, the bacterial community responded positively at the rice tillering stage under O 3 pollution. However, several keystone bacterial guilds were consistently negatively affected by O 3 pollution in two rice cultivars. These findings indicate that continuously O 3 pollution would negatively influence rice agroecosystem and the crop cultivar is important in determining the soil biota responses to elevated O 3 . - Highlights: • We investigated the soil biota in two rice cultivars in presence of elevated O 3 . • The contrasting responses of soil biota were found between two rice cultivars. • Some keystone bacterial guilds were consistently negatively affected by O 3 pollution. • The crop cultivar is important in determining soil biota responses to elevated O 3 . - The crop cultivar is important in determining the soil biota responses to elevated O 3

Ozone injury to celery. [Apium graveolens

Energy Technology Data Exchange (ETDEWEB)

Rich, S.

1966-10-01

Ozone is the principal air pollutant damaging crops in Connecticut. Ozone injury in Connecticut has been found on a number of crops including tobacco, tomatoes, potatoes, spinach, alfalfa, and cereals. This is the first report of ozone damage to celery (Apium graveolens var. dulce) in Connecticut, and perhaps in the United States. On July 7, 1966, celery plants with badly damaged older leaves were found in a commercial garden near Shelton, Connecticut. The injured leaves showed chlorotic and necrotic interveinal areas on their upper surfaces. These areas were slightly depressed. Cross sections of the lesions revealed that the palisade cells were most severely injured. Spinach and carrots growing near the celery showed typical symptoms of ozone damage. To substantiate the diagnosis, young celery plants were exposed to 0.2 ppm of ozone in a well-lighted plastic chamber for 1 to 3 hours. Five days later, these plants developed symptoms indentical to those found on celery in the field. Ozone damage appeared on many crops in southern Connecticut early in July. This injury probably occurred on June 27, when a high concentration of ozone (0.1 ppm) was present in the New Haven area.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-02-15

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Options to Accelerate Ozone Recovery: Ozone and Climate Benefits

Science.gov (United States)

Fleming, E. L.; Daniel, J. S.; Portmann, R. W.; Velders, G. J. M.; Jackman, C. H.; Ravishankara, A. R.

2010-01-01

The humankind or anthropogenic influence on ozone primarily originated from the chlorofluorocarbons and halons (chlorine and bromine). Representatives from governments have met periodically over the years to establish international regulations starting with the Montreal Protocol in 1987, which greatly limited the release of these ozone-depleting substances (DDSs). Two global models have been used to investigate the impact of hypothetical reductions in future emissions of ODSs on total column ozone. The investigations primarily focused on chlorine- and bromine-containing gases, but some computations also included nitrous oxide (N2O). The Montreal Protocol with ODS controls have been so successful that further regulations of chlorine- and bromine-containing gases could have only a fraction of the impact that regulations already in force have had. if all anthropogenic ODS emissions were halted beginning in 2011, ozone is calculated to be higher by about 1-2% during the period 2030-2100 compared to a case of no additional ODS restrictions. Chlorine- and bromine-containing gases and nitrous oxide are also greenhouse gases and lead to warming of the troposphere. Elimination of N 20 emissions would result in a reduction of radiative forcing of 0.23 W/sq m in 2100 than presently computed and destruction of the CFC bank would produce a reduction in radiative forcing of 0.005 W/sq m in 2100. This paper provides a quantitative way to consider future regulations of the CFC bank and N 20 emissions

California Baseline Ozone Transport Study (CABOTS): Ozonesonde Measurements

Science.gov (United States)

Eiserloh, A. J., Jr.; Chiao, S.; Spitze, J.; Cauley, S.; Clark, J.; Roberts, M.

2016-12-01

Because the EPA recently lowered the ambient air quality standard for the 8-hr average of ozone (O3) to70 ppbv, California must continue to achieve significant reductions in ozone precursor emissions and prepare for new State Implementation Plans (SIP) to demonstrate how ground-level ambient ozone will be reduced below the new health-based standard. Prior studies suggest that background levels of ozone traveling across the Pacific Ocean can significantly influence surface ozone throughout California, particularly during the spring. Evidence has been presented indicating that background levels of ozone continue to increase in the western United States over the recent few decades, implying more ozone exceedances in the future. To better understand the contributions of the external natural and anthropogenic pollution sources as well as atmospheric processes for surface ozone concentrations in California during the spring and summer months, the California Baseline Ozone Transport Study (CABOTS) has been established. One major goal of CABOTS is to implement near daily ozonesonde measurements along the California Coast to quantify background ozone aloft before entering the State during high ozone season. CABOTS has been ongoing from May through August of 2016 launching ozonesondes from Bodega Bay and Half Moon Bay, California. The temporal progression of ozonesonde measurements and subsequent analysis of the data will be discussed with a focus on the contribution of background ozone to surface ozone sites inland as well as likely origins of layers aloft. Comparisons of current ozonesondes versus prior ozonesonde studies of California will also be performed. A few selected cases of high ozone layers moving onshore from different sources will be discussed as well.

Ozone decomposition kinetics on alumina: effects of ozone partial pressure, relative humidity and repeated oxidation cycles

Directory of Open Access Journals (Sweden)

R. C. Sullivan

2004-01-01

Full Text Available The room temperature kinetics of gas-phase ozone loss via heterogeneous interactions with thin alumina films has been studied in real-time using 254nm absorption spectroscopy to monitor ozone concentrations. The films were prepared from dispersions of fine alumina powder in methanol and their surface areas were determined by an in situ procedure using adsorption of krypton at 77K. The alumina was found to lose reactivity with increasing ozone exposure. However, some of the lost reactivity could be recovered over timescales of days in an environment free of water, ozone and carbon dioxide. From multiple exposures of ozone to the same film, it was found that the number of active sites is large, greater than 1.4x1014 active sites per cm2 of surface area or comparable to the total number of surface sites. The films maintain some reactivity at this point, which is consistent with there being some degree of active site regeneration during the experiment and with ozone loss being catalytic to some degree. The initial uptake coefficients on fresh films were found to be inversely dependent on the ozone concentration, varying from roughly 10-6 for ozone concentrations of 1014 molecules/cm3 to 10-5 at 1013 molecules/cm3. The initial uptake coefficients were not dependent on the relative humidity, up to 75%, within the precision of the experiment. The reaction mechanism is discussed, as well as the implications these results have for assessing the effect of mineral dust on atmospheric oxidant levels.

Ozone Damages to Mediterranean Crops: Physiological Responses

Directory of Open Access Journals (Sweden)

Albino Maggio

2008-03-01

Full Text Available In this brief review we analyzed some aspects of tropospheric ozone damages to crop plants. Specifically, we addressed this issue to Mediterranean environments, where plant response to multiple stresses may either exacerbate or counteract deleterious ozone effects. After discussing the adequacy of current models to predict ozone damages to Mediterranean crops, we present a few examples of physiological responses to drought and salinity stress that generally overlap with seasonal ozone peaks in Southern Italy. The co-existence of multiple stresses is then analyzed in terms of stomatal vs. non-stomatal control of ozone damages. Recent results on osmoprotectant feeding experiments, as a non-invasive strategy to uncouple stomatal vs. non stomatal contribution to ozone protection, are also presented. In the final section, we discuss critical needs in ozone research and the great potential of plant model systems to unravel multiple stress responses in agricultural crops.

Ozone Damages to Mediterranean Crops: Physiological Responses

Directory of Open Access Journals (Sweden)

Massimo Fagnano

2011-02-01

Full Text Available In this brief review we analyzed some aspects of tropospheric ozone damages to crop plants. Specifically, we addressed this issue to Mediterranean environments, where plant response to multiple stresses may either exacerbate or counteract deleterious ozone effects. After discussing the adequacy of current models to predict ozone damages to Mediterranean crops, we present a few examples of physiological responses to drought and salinity stress that generally overlap with seasonal ozone peaks in Southern Italy. The co-existence of multiple stresses is then analyzed in terms of stomatal vs. non-stomatal control of ozone damages. Recent results on osmoprotectant feeding experiments, as a non-invasive strategy to uncouple stomatal vs. non stomatal contribution to ozone protection, are also presented. In the final section, we discuss critical needs in ozone research and the great potential of plant model systems to unravel multiple stress responses in agricultural crops.

Global Ozone Distribution relevant to Human Health: Metrics and present day levels from the Tropospheric Ozone Assessment Report (TOAR)

Science.gov (United States)

Fleming, Z. L.; Doherty, R. M.; von Schneidemesser, E.; Cooper, O. R.; Malley, C.; Colette, A.; Xu, X.; Pinto, J. P.; Simpson, D.; Schultz, M. G.; Hamad, S.; Moola, R.; Solberg, S.; Feng, Z.

2017-12-01

Using stations from the TOAR surface ozone database, this study quantifies present-day global and regional distributions of five ozone metrics relevant for both short-term and long-term human exposure. These metrics were explored at ozone monitoring sites globally, and re-classified for this project as urban or non-urban using population densities and night-time lights. National surface ozone limit values are usually related to an annual number of exceedances of daily maximum 8-hour running mean (MDA8), with many countries not even having any ozone limit values. A discussion and comparison of exceedances in the different ozone metrics, their locations and the seasonality of exceedances provides clues as to the regions that potentially have more serious ozone health implications. Present day ozone levels (2010-2014) have been compared globally and show definite geographical differences (see Figure showing the annual 4th highest MDA8 for present day ozone for all non-urban stations). Higher ozone levels are seen in western compared to eastern US, and between southern and northern Europe, and generally higher levels in east Asia. The metrics reflective of peak concentrations show highest values in western North America, southern Europe and East Asia. A number of the metrics show similar distributions of North-South gradients, most prominent across Europe and Japan. The interquartile range of the regional ozone metrics was largest in East Asia, higher for urban stations in Asia but higher for non-urban stations in Europe and North America. With over 3000 monitoring stations included in this analysis and despite the higher densities of monitoring stations in Europe, north America and East Asia, this study provides the most comprehensive global picture to date of surface ozone levels in terms of health-relevant metrics.

The Effect of Gaseous Ozone in Infected Root Canal

Science.gov (United States)

Ajeti, Nova Nexhmije; Pustina-Krasniqi, Teuta; Apostolska, Sonja

2018-01-01

OBJECTIVES: During the treatment of chronic apical periodontitis and pulp necrosis the main role is to irrigate the root canal. AIM: The aim of this in vivo study was to irrigate with 0.9% NaCl (Natrium Chloride), 2.5 % NaOCl (Sodium Hypochlorite Solution, Sigma Aldrich - Germany) and 2% CHX (Chlorhexidine Digluconate Solution, Sigma Aldrich - Spain) combined with Gaseous Ozone (Prozone WH, Austria). MATERIAL AND METHODS: This study was realised in the University Dentistry Clinical Centre of Kosovo (UDCCK), respectively in the Department of Endodontic and Dental Pathology, Dental Branch, Faculty of Medicine, Prishtina, Kosovo. The 40 subjects involved in this study belonged to both genders, in age between 15 -65 years. The sample selection was randomised. The retroalveolar radiography for each patient was taken in the suspected tooth. As a therapeutic plan the authors decided to disinfect the root canal with the irrigants, as follows: 2.5 % NaOCl, 2 % CHX and gaseous ozone. RESULTS: The statistical analyses were based on Kruskal - Vallis test, X - test, DF = 3, r irrigants 0.9%, 2.5 % NaOCl and 2% CHX, it was concluded that the number of colonies of aerobic and anaerobic bacteria was reduced. PMID:29531611

Ozone from fireworks: Chemical processes or measurement interference?

Science.gov (United States)

Xu, Zheng; Nie, Wei; Chi, Xuguang; Huang, Xin; Zheng, Longfei; Xu, Zhengning; Wang, Jiaping; Xie, Yuning; Qi, Ximeng; Wang, Xinfeng; Xue, Likun; Ding, Aijun

2018-08-15

Fireworks have been identified as one ozone source by photolyzing NO 2 or O 2 and are believed to potentially be important for the nighttime ozone during firework events. In this study, we conducted both lab and field experiments to test two types of fireworks with low and high energy with the goal to distinguish whether the visible ozone signal during firework displays is real. The results suggest that previous understanding of the ozone formation mechanism during fireworks is misunderstood. Ultraviolet ray (UV)-based ozone monitors are interfered by aerosols and some specific VOCs. High-energy fireworks emit high concentrations of particular matters and low VOCs that the artificial ozone can be easily removed by an aerosol filter. Low-energy fireworks emit large amounts of VOCs mostly from the combustion of the cardboard from fireworks that largely interferes with the ozone monitor. Benzene and phenol might be major contributors to the artificial ozone signal. We further checked the nighttime ozone concentration in Jinan and Beijing, China, during Chinese New Year, a period with intense fireworks. A signal of 3-8ppbv ozone was detected and positively correlated to NO and SO 2 , suggesting a considerable influence of these chemicals in interfering with ambient ozone monitoring. Copyright © 2018 Elsevier B.V. All rights reserved.

Ozone, Climate, and Global Atmospheric Change.

Science.gov (United States)

Levine, Joel S.

1992-01-01

Presents an overview of global atmospheric problems relating to ozone depletion and global warming. Provides background information on the composition of the earth's atmosphere and origin of atmospheric ozone. Describes causes, effects, and evidence of ozone depletion and the greenhouse effect. A vignette provides a summary of a 1991 assessment of…

Drift-corrected Odin-OSIRIS ozone product: algorithm and updated stratospheric ozone trends

Directory of Open Access Journals (Sweden)

A. E. Bourassa

2018-01-01

Full Text Available A small long-term drift in the Optical Spectrograph and Infrared Imager System (OSIRIS stratospheric ozone product, manifested mostly since 2012, is quantified and attributed to a changing bias in the limb pointing knowledge of the instrument. A correction to this pointing drift using a predictable shape in the measured limb radiance profile is implemented and applied within the OSIRIS retrieval algorithm. This new data product, version 5.10, displays substantially better both long- and short-term agreement with Microwave Limb Sounder (MLS ozone throughout the stratosphere due to the pointing correction. Previously reported stratospheric ozone trends over the time period 1984–2013, which were derived by merging the altitude–number density ozone profile measurements from the Stratospheric Aerosol and Gas Experiment (SAGE II satellite instrument (1984–2005 and from OSIRIS (2002–2013, are recalculated using the new OSIRIS version 5.10 product and extended to 2017. These results still show statistically significant positive trends throughout the upper stratosphere since 1997, but at weaker levels that are more closely in line with estimates from other data records.

Effect of Pulse Width on Oxygen-fed Ozonizer

Science.gov (United States)

Okada, Sho; Wang, Douyan; Namihira, Takao; Katsuki, Sunao; Akiyama, Hidenori

Though general ozonizers based on silent discharge (barrier discharge) have been used to supply ozone at many industrial situations, there is still some problem, such as improvements of ozone yield. In this work, ozone was generated by pulsed discharge in order to improve the characteristics of ozone generation. It is known that a pulse width gives strong effect to the improvement of energy efficiency in exhaust gas processing. In this paper, the effect of pulse duration on ozone generation by pulsed discharge in oxygen would be reported.

Comparative ozone responses of cutleaf coneflowers (Rudbeckia laciniata var. digitata, var. ampla) from Rocky Mountain and Great Smoky Mountains National Parks, USA.

Science.gov (United States)

Neufeld, Howard S; Johnson, Jennifer; Kohut, Robert

2018-01-01

Cutleaf coneflower (Rudbeckia laciniata L. var. digitata) is native to Great Smoky Mountains National Park (GRSM) and an ozone bioindicator species. Variety ampla, whose ozone sensitivity is less well known, is native to Rocky Mountain National Park (ROMO). In the early 2000s, researchers found putative ozone symptoms on var. ampla and rhizomes were sent to Appalachian State University to verify that the symptoms were the result of ozone exposure. In 2011, potted plants were exposed to ambient ozone from May to August. These same plants were grown in open-top chambers (OTCs) in 2012 and 2013, and exposed to charcoal-filtered (CF), non-filtered (NF), elevated ozone (EO), NF+50ppb in 2012 for 47days and NF+30/NF+50ppb ozone in 2013 for 36 and 36days, respectively. Ozone symptoms similar to those found in ROMO (blue-black adaxial stippling) were reproduced both in ambient air and in the OTCs. Both varieties exhibited foliar injury in the OTCs in an exposure-dependent manner, verifying that symptoms resulted from ozone exposure. In two of the three study years, var. digitata appeared more sensitive than var. ampla. Exposure to EO caused reductions in ambient photosynthetic rate (A) and stomatal conductance (g s ) for both varieties. Light response curves indicated that ozone reduced A, g s , and the apparent quantum yield while it increased the light compensation point. In CF air, var. ampla had higher light saturated A (18.2±1.04 vs 11.6±0.37μmolm -2 s -1 ), higher light saturation (1833±166.7 vs 1108±141.7μmolm -2 s -1 ), and lower Ci/Ca ratio (0.67±0.01 vs 0.77±0.01) than var. digitata. Coneflowers in both Parks are adversely affected by exposure to ambient ozone and if ozone concentrations increase in the Rocky Mountains, greater amounts of injury on var. ampla can be expected. Copyright © 2017 Elsevier B.V. All rights reserved.

Diurnal changes in photosynthetic parameters of Populus tremuloides, modulated by elevated concentrations of CO2 and/or O3 and daily climatic variation

International Nuclear Information System (INIS)

Kets, Katre; Darbah, Joseph N.T.; Sober, Anu; Riikonen, Johanna; Sober, Jaak; Karnosky, David F.

2010-01-01

The diurnal changes in light-saturated photosynthesis (Pn) under elevated CO 2 and/or O 3 in relation to stomatal conductance (g s ), water potential, intercellular [CO 2 ], leaf temperature and vapour-pressure difference between leaf and air (VPD L ) were studied at the Aspen FACE site. Two aspen (Populus tremuloides Michx.) clones differing in their sensitivity to ozone were measured. The depression in Pn was found after 10:00 h. The midday decline in Pn corresponded with both decreased g s and decreased Rubisco carboxylation efficiency, Vc max . As a result of increasing VPD L , g s decreased. Elevated [CO 2 ] resulted in more pronounced midday decline in Pn compared to ambient concentrations. Moreover, this decline was more pronounced under combined treatment compared to elevated CO 2 treatment. The positive impact of CO 2 on Pn was relatively more pronounced in days with environmental stress but relatively less pronounced during midday depression. The negative impact of ozone tended to decrease in both cases. - Diurnal and seasonal patterns of environmental stress (drought, high air temperature) affects a relative impact of elevated concentrations of CO 2 and O 3 on trees.

Ozone-induced H2O2 accumulation in field-grown aspen and birch is linked to foliar ultrastructure and peroxisomal activity

Science.gov (United States)

E. Oksanen; E. Häikiö; J. Sober; D.F. Karnosky

2003-01-01

Saplings of three aspen (Populus tremuloides) genotypes and seedlings of paper birch (Betula papyrifera) were exposed to elevated ozone (1.5x ambient) and 560 p.p.m. CO2, singly and in combination, from 1998 at the Aspen-FACE (free-air CO2 enrichment) site (Rhinelander, USA).

Analysis of the summertime buildup of tropospheric ozone abundances over the Middle East and North Africa as observed by the Tropospheric Emission Spectrometer instrument

Science.gov (United States)

Liu, Jane J.; Jones, Dylan B. A.; Worden, John R.; Noone, David; Parrington, Mark; Kar, Jay

2009-03-01

We use the GEOS-Chem chemical transport model to interpret observations of tropospheric ozone from the Tropospheric Emission Spectrometer (TES) satellite instrument in summer 2005. Observations from TES reveal elevated ozone in the middle troposphere (500-400 hPa) across North Africa and the Middle East. Observed ozone abundances in the middle troposphere are at a maximum in summer and a minimum in winter, consistent with the previously predicted summertime "Middle East ozone maximum." This summertime enhancement in ozone is associated with the Arabian and Sahara anticyclones, centered over the Zagros and Atlas Mountains, respectively. These anticyclones isolate the middle troposphere over northeast Africa and the Middle East, with westerlies to the north and easterlies to the south, facilitating the buildup of ozone. Over the Middle East, we find that in situ production and transport from Asia provides comparable contributions of 30-35% to the ozone buildup. Over North Africa, in situ production is dominant (at about 20%), with transport from Asia, North America, and equatorial Africa each contributing about 10-15% to the total ozone. We find that although the eastern Mediterranean is characterized by strong descent in the middle and upper troposphere in summer, transport from the boundary layer accounts for about 25% of the local Middle Eastern contribution to the ozone enhancement in the middle troposphere. This upward transport of boundary layer air is associated with orographic lifting along the Zagros Mountains in Iran and the Asir and Hijaz Mountain ranges in Saudi Arabia, and is consistent with TES observations of deuterated water.

On the local and regional influence on ground-level ozone concentrations in Hong Kong

International Nuclear Information System (INIS)

So, K.L.; Wang, T.

2003-01-01

It is imperative to consider regional scale emissions and dynamic transport in managing ozone pollution in Hong Kong. - Hong Kong is a densely populated city situated in the fast developing Pearl River Delta of southern China. In this study, the recent data on ozone (O 3 ) and related air pollutants obtained at three sites in Hong Kong are analyzed to show the variations of O 3 in urban, sub-urban and rural areas and the possible regional influences. Highest monthly averaged O 3 was found at a northeastern rural site and lowest O 3 level was observed at an urban site. The levels of NO x , CO, SO 2 and PM 10 showed a different spatial pattern with the highest level in the urban site and lowest at the rural site. Analysis of chemical species ratios such as SO 2 /NO x and CO/NO x indicated that the sites were under the influences of local and regional emissions to varying extents reflecting the characteristics of emission sources surround the respective sites. Seasonal pattern of O 3 is examined. Low O 3 level was found in summer and elevated levels occurred in autumn and spring. The latter appears different from the previous result obtained in 1996 indicating a single maximum occurring in autumn. Principal component analysis was used to further elucidate the relationships of air pollutants at each site. As expected, the O 3 variation in the northeastern rural area was largely determined by regional chemical and transport processes, while the O 3 variability at the southwestern suburban and urban sites were more influenced by local emissions. Despite the large difference in O 3 levels across the sites, total potential ozone (O 3 +NO 2 ) showed little variability. Cases of high O 3 episodes were presented and elevated O 3 levels were formed under the influence of tropical cyclone bringing in conditions of intense sunlight, high temperature and light winds. Elevated O 3 levels were also found to correlate with enhanced ratio of SO 2 to NO x , suggesting influence of

Information content of ozone retrieval algorithms

Science.gov (United States)

Rodgers, C.; Bhartia, P. K.; Chu, W. P.; Curran, R.; Deluisi, J.; Gille, J. C.; Hudson, R.; Mateer, C.; Rusch, D.; Thomas, R. J.

1989-01-01

The algorithms are characterized that were used for production processing by the major suppliers of ozone data to show quantitatively: how the retrieved profile is related to the actual profile (This characterizes the altitude range and vertical resolution of the data); the nature of systematic errors in the retrieved profiles, including their vertical structure and relation to uncertain instrumental parameters; how trends in the real ozone are reflected in trends in the retrieved ozone profile; and how trends in other quantities (both instrumental and atmospheric) might appear as trends in the ozone profile. No serious deficiencies were found in the algorithms used in generating the major available ozone data sets. As the measurements are all indirect in someway, and the retrieved profiles have different characteristics, data from different instruments are not directly comparable.

Ozone Gardens for the Citizen Scientist

Science.gov (United States)

Pippin, Margaret; Reilly, Gay; Rodjom, Abbey; Malick, Emily

2016-01-01

NASA Langley partnered with the Virginia Living Museum and two schools to create ozone bio-indicator gardens for citizen scientists of all ages. The garden at the Marshall Learning Center is part of a community vegetable garden designed to teach young children where food comes from and pollution in their area, since most of the children have asthma. The Mt. Carmel garden is located at a K-8 school. Different ozone sensitive and ozone tolerant species are growing and being monitored for leaf injury. In addition, CairClip ozone monitors were placed in the gardens and data are compared to ozone levels at the NASA Langley Chemistry and Physics Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, VA. Leaf observations and plant measurements are made two to three times a week throughout the growing season.

Impacts of stratospheric sulfate geoengineering on tropospheric ozone

Directory of Open Access Journals (Sweden)

L. Xia

2017-10-01

Full Text Available A range of solar radiation management (SRM techniques has been proposed to counter anthropogenic climate change. Here, we examine the potential effects of stratospheric sulfate aerosols and solar insolation reduction on tropospheric ozone and ozone at Earth's surface. Ozone is a key air pollutant, which can produce respiratory diseases and crop damage. Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosols and solar dimming on atmospheric ozone concentrations. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations, while sulfate injection decreases it. A fundamental difference between the two geoengineering schemes is the importance of heterogeneous reactions in the photochemical ozone balance with larger stratospheric sulfate abundance, resulting in increased ozone depletion in mid- and high latitudes. This reduces the net transport of stratospheric ozone into the troposphere and thus is a key driver of the overall decrease in surface ozone. At the same time, the change in stratospheric ozone alters the tropospheric photochemical environment due to enhanced ultraviolet radiation. A shared factor among both SRM scenarios is decreased chemical ozone loss due to reduced tropospheric humidity. Under insolation reduction, this is the dominant factor giving rise to the global surface ozone increase. Regionally, both surface ozone increases and decreases are found for both scenarios; that is, SRM would affect regions of the world differently in terms of air

Impacts of stratospheric sulfate geoengineering on tropospheric ozone

Science.gov (United States)

Xia, Lili; Nowack, Peer J.; Tilmes, Simone; Robock, Alan

2017-10-01

A range of solar radiation management (SRM) techniques has been proposed to counter anthropogenic climate change. Here, we examine the potential effects of stratospheric sulfate aerosols and solar insolation reduction on tropospheric ozone and ozone at Earth's surface. Ozone is a key air pollutant, which can produce respiratory diseases and crop damage. Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosols and solar dimming on atmospheric ozone concentrations. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations, while sulfate injection decreases it. A fundamental difference between the two geoengineering schemes is the importance of heterogeneous reactions in the photochemical ozone balance with larger stratospheric sulfate abundance, resulting in increased ozone depletion in mid- and high latitudes. This reduces the net transport of stratospheric ozone into the troposphere and thus is a key driver of the overall decrease in surface ozone. At the same time, the change in stratospheric ozone alters the tropospheric photochemical environment due to enhanced ultraviolet radiation. A shared factor among both SRM scenarios is decreased chemical ozone loss due to reduced tropospheric humidity. Under insolation reduction, this is the dominant factor giving rise to the global surface ozone increase. Regionally, both surface ozone increases and decreases are found for both scenarios; that is, SRM would affect regions of the world differently in terms of air pollution. In conclusion

Tropospheric ozone column retrieval at northern mid-latitudes from the Ozone Monitoring Instrument by means of a neural network algorithm

Directory of Open Access Journals (Sweden)

P. Sellitto

2011-11-01

Full Text Available Monitoring tropospheric ozone from space is of critical importance in order to gain more thorough knowledge on phenomena affecting air quality and the greenhouse effect. Deriving information on tropospheric ozone from UV/VIS nadir satellite spectrometers is difficult owing to the weak sensitivity of the measured radiance spectra to variations of ozone in the troposphere. Here we propose an alternative method of analysis to retrieve tropospheric ozone columns from Ozone Monitoring Instrument radiances by means of a neural network algorithm. An extended set of ozone sonde measurements at northern mid-latitudes for the years 2004–2008 has been considered as the training and test data set. The design of the algorithm is extensively discussed. Our retrievals are compared to both tropospheric ozone residuals and optimal estimation retrievals over a similar independent test data set. Results show that our algorithm has comparable accuracy with respect to both correlative methods and its performance is slightly better over a subset containing only European ozone sonde stations. Possible sources of errors are analyzed. Finally, the capabilities of our algorithm to derive information on boundary layer ozone are studied and the results critically discussed.

Mechanisms of Action Involved in Ozone Therapy: Is healing induced via a mild oxidative stress?

Directory of Open Access Journals (Sweden)

Sagai Masaru

2011-12-01

Full Text Available Abstract The potential mechanisms of action of ozone therapy are reviewed in this paper. The therapeutic efficacy of ozone therapy may be partly due the controlled and moderate oxidative stress produced by the reactions of ozone with several biological components. The line between effectiveness and toxicity of ozone may be dependent on the strength of the oxidative stress. As with exercise, it is well known that moderate exercise is good for health, whereas excessive exercise is not. Severe oxidative stress activates nuclear transcriptional factor kappa B (NFκB, resulting in an inflammatory response and tissue injury via the production of COX2, PGE2, and cytokines. However, moderate oxidative stress activates another nuclear transcriptional factor, nuclear factor-erythroid 2-related factor 2 (Nrf2. Nrf2 then induces the transcription of antioxidant response elements (ARE. Transcription of ARE results in the production of numerous antioxidant enzymes, such as SOD, GPx, glutathione-s-transferase(GSTr, catalase (CAT, heme-oxygenase-1 (HO-1, NADPH-quinone-oxidoreductase (NQO-1, phase II enzymes of drug metabolism and heat shock proteins (HSP. Both free antioxidants and anti-oxidative enzymes not only protect cells from oxidation and inflammation but they may be able to reverse the chronic oxidative stress. Based on these observations, ozone therapy may also activate Nrf2 via moderate oxidative stress, and suppress NFκB and inflammatory responses. Furthermore, activation of Nrf2 results in protection against neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Mild immune responses are induced via other nuclear transcriptional factors, such as nuclear factor of activated T-cells (NFAT and activated protein-1 (AP-1. Additionally, the effectiveness of ozone therapy in vascular diseases may also be explained by the activation of another nuclear transcriptional factor, hypoxia inducible factor-1α (HIF-1a, which is also induced via

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-27

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

Impacts of ozone on trees and crops

International Nuclear Information System (INIS)

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

2007-01-01

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

Defense meteorological satellite measurements of total ozone

International Nuclear Information System (INIS)

Lovill, J.E.; Ellis, J.S.; Luther, F.M.; Sullivan, R.J.; Weichel, R.L.

1992-01-01

A multichannel filter radiometer (MFR) on Defense Meteorological Satellites (DMS) that measured total ozone on a global-scale from March 1977 - February 1980 is described. The total ozone data measured by the MFR were compared with total ozone data taken by surfaced-based Dobson spectrophotometers. When comparisons were made for five months, the Dobson spectrophotometer measured 2-5% more total ozone than the MFR. Comparisons between the Dobson spectrophotometer and the MFR showed a reduced RMS difference as the comparisons were made at closer proximity. A Northern Hemisphere total ozone distribution obtained from MFR data is presented

Health Effects of Ozone and Particle Pollution

Science.gov (United States)

... this page: Health Effects of Ozone and Particle Pollution Two types of air pollution dominate in the ... So what are ozone and particle pollution? Ozone Pollution It may be hard to imagine that pollution ...

Ozone sonde cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere

Directory of Open Access Journals (Sweden)

H. Vömel

2010-04-01

Full Text Available Laboratory measurements of the Electrochemical Concentration Cell (ECC ozone sonde cell current using ozone free air as well as defined amounts of ozone reveal that background current measurements during sonde preparation are neither constant as a function of time, nor constant as a function of ozone concentration. Using a background current, measured at a defined timed after exposure to high ozone may often overestimate the real background, leading to artificially low ozone concentrations in the upper tropical troposphere, and may frequently lead to operator dependent uncertainties. Based on these laboratory measurements an improved cell current to partial pressure conversion is proposed, which removes operator dependent variability in the background reading and possible artifacts in this measurement. Data from the Central Equatorial Pacific Experiment (CEPEX have been reprocessed using the improved background treatment based on these laboratory measurements. In the reprocessed data set near-zero ozone events no longer occur. At Samoa, Fiji, Tahiti, and San Cristóbal, nearly all near-zero ozone concentrations occur in soundings with larger background currents. To a large extent, these events are no longer observed in the reprocessed data set using the improved background treatment.

Expected Performance of Ozone Climate Data Records from Ozone Mapping and Profiler Suite Limb Profiler

Science.gov (United States)

Xu, P. Q.; Rault, D. F.; Pawson, S.; Wargan, K.; Bhartia, P. K.

2012-01-01

The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) was launched on board of the Soumi NPP space platform in late October 2011. It provides ozone-profiling capability with high-vertical resolution from 60 Ian to cloud top. In this study, an end-to-end Observing System Simulation Experiment (OSSE) of OMPS/LP ozone is discussed. The OSSE was developed at NASA's Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System (GEOS-5) data assimilation system. The "truth" for this OSSE is built by assimilating MLS profiles and OMI ozone columns, which is known to produce realistic three-dimensional ozone fields in the stratosphere and upper troposphere. OMPS/LP radiances were computed at tangent points computed by an appropriate orbital model. The OMPS/LP forward RT model, Instrument Models (IMs) and EDR retrieval model were introduced and pseudo-observations derived. The resultant synthetic OMPS/LP observations were evaluated against the "truth" and subsequently these observations were assimilated into GEOS-5. Comparison of this assimilated dataset with the "truth" enables comparisons of the likely uncertainties in 3-D analyses of OMPS/LP data. This study demonstrated the assimilation capabilities of OMPS/LP ozone in GEOS-5, with the monthly, zonal mean (O-A) smaller than 0.02ppmv at all levels, the nns(O-A) close to O.lppmv from 100hPa to 0.2hPa; and the mean(O-B) around the 0.02ppmv for all levels. The monthly zonal mean analysis generally agrees to within 2% of the truth, with larger differences of 2-4% (0.1-0.2ppmv) around 10hPa close to North Pole and in the tropical tropopause region, where the difference is above 20% due to the very low ozone concentrations. These OSSEs demonstrated that, within a single data assimilation system and the assumption that assimilated MLS observations provide a true rendition of the stratosphere, the OMPS/LP ozone data are likely to produce accurate analyses through much of the stratosphere

Elevated CO2 and O3t concentrations differentially affect selected groups of the fauna in temperate forest soils

Science.gov (United States)

Gladys I. Loranger; Kurt S. Pregitzer; John S. King

2004-01-01

Rising atmospheric CO2 concentrations may change soil fauna abundance. How increase of tropospheric ozone (O3t) concentration will modify these responses is still unknown. We have assessed independent and interactive effects of elevated [CO2] and [O3t] on selected groups of soil...

Features of ozone intraannual variability in polar regions based on ozone sounding data obtained at the Resolute and Amundsen-Scott stations

Energy Technology Data Exchange (ETDEWEB)

Gruzdev, A.N.; Sitnov, S.A. (AN SSSR, Institut Fiziki Atmosfery, Moscow (USSR))

1991-04-01

Ozone sounding data obtained at the Resolute and Amundsen-Scott stations are used to analyze ozone intraannual variability in Southern and Northern polar regions. For the Arctic, in particular, features associated with winter stratospheric warmings, stratospheric-tropospheric exchange, and the isolated evolution of surface ozone are noted. Correlative connections between ozone and temperature making it possible to concretize ozone variability mechanisms are analyzed. 31 refs.

Observing Tropospheric Ozone From Space

Science.gov (United States)

Fishman, Jack

2000-01-01

The importance of tropospheric ozone embraces a spectrum of relevant scientific issues ranging from local environmental concerns, such as damage to the biosphere and human health, to those that impact global change questions, Such is climate warming. From an observational perspective, the challenge is to determine the tropospheric ozone global distribution. Because its lifetime is short compared with other important greenhouse gases that have been monitored over the past several decades, the distribution of tropospheric ozone cannot be inferred from a relatively small set of monitoring stations. Therefore, the best way to obtain a true global picture is from the use of space-based instrumentation where important spatial gradients over vast ocean expanses and other uninhabited areas can be properly characterized. In this paper, the development of the capability to measure tropospheric ozone from space over the past 15 years is summarized. Research in the late 1980s successfully led to the determination of the climatology of tropospheric ozone as a function of season; more recently, the methodology has improved to the extent where regional air pollution episodes can be characterized. The most recent modifications now provide quasi-global (50 N) to 50 S) maps on a daily basis. Such a data set would allow for the study of long-range (intercontinental) transport of air pollution and the quantification of how regional emissions feed into the global tropospheric ozone budget. Future measurement capabilities within this decade promise to offer the ability to provide Concurrent maps of the precursors to the in situ formation of tropospheric ozone from which the scientific community will gain unprecedented insight into the processes that control global tropospheric chemistry

Ozone pretreatment and fermentative hydrolysis of wheat straw

Science.gov (United States)

Ben'ko, E. M.; Chukhchin, D. G.; Lunin, V. V.

2017-11-01

Principles of the ozone pretreatment of wheat straw for subsequent fermentation into sugars are investigated. The optimum moisture contents of straw in the ozonation process are obtained from data on the kinetics of ozone absorbed by samples with different contents of water. The dependence of the yield of reducing sugars in the fermentative reaction on the quantity of absorbed ozone is established. The maximum conversion of polysaccharides is obtained at ozone doses of around 3 mmol/g of biomass, and it exceeds the value for nonozonated samples by an order of magnitude. The yield of sugar falls upon increasing the dose of ozone. The process of removing lignin from the cell walls of straw during ozonation is visualized by means of scanning electron microscopy.

Importance of energetic solar protons in ozone depletion

Energy Technology Data Exchange (ETDEWEB)

Stephenson, J A.E.; Scourfield, M W.J. [Natal Univ., Durban (South Africa). Space Physics Research Inst.

1991-07-11

CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by {approx} 9% over {approx} 20% of the total area between the South Pole and latitude 70{sup o}S. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored. (author).

Importance of energetic solar protons in ozone depletion

International Nuclear Information System (INIS)

Stephenson, J.A.E.; Scourfield, M.W.J.

1991-01-01

CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by ∼ 9% over ∼ 20% of the total area between the South Pole and latitude 70 o S. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored. (author)

Analysis of Ozone in Cloudy Versus Clear Sky Conditions

Science.gov (United States)

Strode, Sarah; Douglass, Anne; Ziemke, Jerald

2016-01-01

Convection impacts ozone concentrations by transporting ozone vertically and by lofting ozone precursors from the surface, while the clouds and lighting associated with convection affect ozone chemistry. Observations of the above-cloud ozone column (Ziemke et al., 2009) derived from the OMI instrument show geographic variability, and comparison of the above-cloud ozone with all-sky tropospheric ozone columns from OMI indicates important regional differences. We use two global models of atmospheric chemistry, the GMI chemical transport model (CTM) and the GEOS-5 chemistry climate model, to diagnose the contributions of transport and chemistry to observed differences in ozone between areas with and without deep convection, as well as differences in clean versus polluted convective regions. We also investigate how the above-cloud tropospheric ozone from OMI can provide constraints on the relationship between ozone and convection in a free-running climate simulation as well as a CTM.

Pollution Control Using Ozone

DEFF Research Database (Denmark)

2017-01-01

This invention relates to a method for cleaning air comprising one or more pollutants, the method comprising contacting the air with thermal decompositions products of ozone.......This invention relates to a method for cleaning air comprising one or more pollutants, the method comprising contacting the air with thermal decompositions products of ozone....

Ozone disintegration kinetics in the reactor for tyres decomposition

International Nuclear Information System (INIS)

Golota, V.I.; Manujlenko, O.V.; Taran, G.V.; Pis'menetskij, A.S.; Zamuriev, A.A.

2010-01-01

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.

Health Effects of Ozone Pollution

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2015-01-01

A two-year experiment exposing Acer truncatum Bunge seedlings to elevated ozone (O 3 ) concentrations above ambient air (AO) and drought stress (DS) was carried out using open-top chambers (OTCs) in a suburb of Beijing in north China in 2012–2013. The results suggested that AO and DS had both significantly reduced leaf mass area (LMA), stomatal conductance (Gs), light saturated photosynthetic rate (A sat ) as well as above and below ground biomass at the end of the experiment. It appeared that while drought stress mitigated the expression of foliar injury, LMA, leaf photosynthetic pigments, height growth and basal diameter, due to limited carbon fixation, the O 3 – induced reductions in A sat , Gs and total biomass were enhanced 23.7%. 15.5% and 8.1% respectively. These data suggest that when the whole plant was considered that drought under the conditions of this experiment did not protect the Shantung maple seedlings from the effects of O 3 . - Highlights: • The response of Acer truncatum Bunge to drought and ozone was investigated. • Drought could mitigate the foliage injury and leaf photosynthetic pigments. • The O 3 -induced reductions in Asat, Gs and total biomass were enhanced by drought. - Drought didn't protect Shantung maple from O 3 effects but rather cause more reductions in biomass

Adrenal-derived stress hormones modulate ozone-induced ...

Science.gov (United States)

Ozone-induced systemic effects are modulated through activation of the neuro-hormonal stress response pathway. Adrenal demedullation (DEMED)or bilateral total adrenalectomy (ADREX) inhibits systemic and pulmonary effect of acute ozone exposure. To understand the influence of adrenal-derived stress hormones in mediating ozone-induced lung injury/inflammation, we assessed global gene expression (mRNA sequencing) and selected proteins in lung tissues from male Wistar-Kyoto rats that underwent DEMED, ADREX, or sham surgery (SHAM)prior to their exposure to air or ozone (1 ppm),4 h/day for 1 or 2days. Ozone exposure significantly changed the expression of over 2300 genes in lungs of SHAM rats, and these changes were markedly reduced in DEMED and ADREX rats. SHAM surgery but not DEMED or ADREX resulted in activation of multiple ozone-responsive pathways, including glucocorticoid, acute phase response, NRF2, and Pl3K-AKT.Predicted targets from sequencing data showed a similarity between transcriptional changes induced by ozone and adrenergic and steroidal modulation of effects in SHAM but not ADREX rats. Ozone-induced Increases in lung 116 in SHAM rats coincided with neutrophilic Inflammation, but were diminished in DEMED and ADREX rats. Although ozone exposure in SHAM rats did not significantly alter mRNA expression of lfny and 11-4, the IL-4 protein and ratio of IL-4 to IFNy (IL-4/IFNy) proteins increased suggesting a tendency for a Th2 response. This did not occur

Solar dynamics influence on the atmospheric ozone

International Nuclear Information System (INIS)

Gogosheva, T.; Grigorieva, V.; Mendeva, B.; Krastev, D.; Petkov, B.

2007-01-01

A response of the atmospheric ozone to the solar dynamics has been studied using the total ozone content data, taken from the satellite experiments GOME on ERS-2 and TOMS-EP together with data obtained from the ground-based spectrophotometer Photon operating in Stara Zagora, Bulgaria during the period 1999-2005. We also use data from surface ozone observations performed in Sofia, Bulgaria. The solar activity was characterized by the sunspot daily numbers W, the solar radio flux at 10.7 cm (F10.7) and the MgII wing-to-core ratio solar index. The impact of the solar activity on the total ozone has been investigated analysing the ozone response to sharp changes of these parameters. Some of the examined cases showed a positive correlation between the ozone and the solar parameters, however, a negative correlation in other cases was found. There were some cases when the sharp increases of the solar activity did not provoke any ozone changes. The solar radiation changes during an eclipse can be considered a particular case of the solar dynamics as this event causes a sharp change of irradiance within a comparatively short time interval. The results of both - the total and surface ozone measurements carried out during the eclipses on 11 August 1999, 31 May 2003 and 29 March 2006 are presented. It was found that the atmospheric ozone behavior shows strong response to the fast solar radiation changes which take place during solar eclipse. (authors)

Chronic erosive seropositive arthritis in a patient with chronic hepatitis C

Directory of Open Access Journals (Sweden)

L P Ananjeva

2008-01-01

Full Text Available Joint syndrome evolution was prospectively followed up in a 49-year-old woman who had serum hepatitis in 1990. When she came to a rheumatologist for the first time in 1999 she complained of occasional joint pain. She did not have joint inflammatory changes at that time but chronic hepatitis С was revealed at the examination. Hepatitis С diagnosis was confirmed by morphological and repeated virological evaluations. During antiviral treatment the pt developed symmetrical polyarthritis involving hand joints. Elevation of cryoglobuline, rheumatoid factor and antinuclear antibodies level was revealed. During the next year polyarthritis recurred and later acquired undulatory course with periods of exacerbation and stabilization. Attempts of treatment with sulfasalazine failed due to transaminase elevation. In 2006 ulnar deviation appeared and rheumatoid factor level remained elevated. MRI showed multiple erosions of carpal bones. Considering features of joint syndrome development joint damage in this pt was regarded as arthritis associated with chronic hepatitis C.

Air Quality Guide for Ozone

Science.gov (United States)

GO! Local Air Quality Conditions Zip Code: State : My Current Location Air Quality Guide for Ozone Ground-level ozone is one of our nation’s most common air pollutants. Use the chart below to help reduce ...

Chronic social isolation and chronic variable stress during early development induce later elevated ethanol intake in adult C57BL/6J mice.

Science.gov (United States)

Lopez, Marcelo F; Doremus-Fitzwater, Tamara L; Becker, Howard C

2011-06-01

). For mice that did not experience CVS, early social isolation resulted in greater ethanol intake compared with group-housed mice (Experiment 3). CVS subsequently resulted in a significant increase in ethanol intake in group-housed mice, but CVS failed to further increase ethanol intake in mice that experienced chronic social isolation early in life (Experiment 3). Overall, female mice consumed more ethanol than males, whether isolated (early or late) or group housed. These results indicate that early but not late social isolation can subsequently influence ethanol consumption in C57BL/6J mice. Thus, the developmental timing of chronic social isolation appears to be an important factor in defining later effects on ethanol self-administration behavior. In addition, experience with CVS early in life results in elevated ethanol intake later in adulthood. Taken together, these results emphasize the important role of early stress experiences that modulate later voluntary ethanol intake during adulthood. Copyright © 2011 Elsevier Inc. All rights reserved.

Granular activated carbon assisted ozonation of cephalexin antibiotic

International Nuclear Information System (INIS)

Akhtar, J.; Amin, N.S.; Imran, M.

2016-01-01

This study investigates removal of cephalexin using ozonation in the presence of granular activated carbon. Initial experiments were carried out about adsorption of cephalexin onto granular activated carbon, effect of catalytic ozonation, and biodegradability of cephalexin solution. The effect of ozonation on pH, ozone utilization efficiency and decomposition byproducts, was observed. Response surface methodology was adopted to optimize three operating parameters pH of solution, ozone supply and cephalexin concentration. GAC assisted ozonation, was found to be effective in decomposing COD (chemical oxygen demand) and cephalexin from solution. Optimum values of variables were pH from 7-8, ozone supply 30 mg/L and 100 mg/L of cephalexin solution. The complete removal of cephalexin and 60% COD removal was achieved at these optimum input values. (author)

Disappearing threat to ozone

Energy Technology Data Exchange (ETDEWEB)

Gribbin, J

1979-02-15

Concern that human activities might disturb the dynamic natural equilibrium of the ozone layer has stemmed from the fact that this layer plays a key part in the ecology of the earth by absorbing harmful ultraviolet radiation which would otherwise penetrate to the ground. Apparently, however, a decline of as much at 15% in total global ozone would have very little effect on climate. A 50% reduction would produce a marked cooling of the stratosphere at 40 km altitude over the tropics, but barely detectable changes in temperature and rainfall in the lower atmosphere. Therefore, biological effects of more uv light at ground level is the only hazard associated with ozone depletion on the scale which might take place.

Breeding of ozone resistant rice: Relevance, approaches and challenges

International Nuclear Information System (INIS)

Frei, Michael

2015-01-01

Tropospheric ozone concentrations have been rising across Asia, and will continue to rise during the 21st century. Ozone affects rice yields through reductions in spikelet number, spikelet fertility, and grain size. Moreover, ozone leads to changes in rice grain and straw quality. Therefore the breeding of ozone tolerant rice varieties is warranted. The mapping of quantitative trait loci (QTL) using bi-parental populations identified several tolerance QTL mitigating symptom formation, grain yield losses, or the degradation of straw quality. A genome-wide association study (GWAS) demonstrated substantial natural genotypic variation in ozone tolerance in rice, and revealed that the genetic architecture of ozone tolerance in rice is dominated by multiple medium and small effect loci. Transgenic approaches targeting tolerance mechanisms such as antioxidant capacity are also discussed. It is concluded that the breeding of ozone tolerant rice can contribute substantially to the global food security, and is feasible using different breeding approaches. - Highlights: • Tropospheric ozone affects millions of hectares of rice land. • Ozone affects rice yield and quality. • Breeding approaches to adapt rice to high ozone are discussed. • Challenges in the breeding of ozone resistant rice are discussed. - This review summarizes the effects of tropospheric ozone on rice and outlines approaches and challenges in the breeding of adapted varieties

Treatability study of the effluent containing reactive blue 21 dye by ozonation and the mass transfer study of ozone

Science.gov (United States)

Velpula, Priyadarshini; Ghuge, Santosh; Saroha, Anil K.

2018-04-01

Ozonation is a chemical treatment process in which ozone reacts with the pollutants present in the effluent by infusion of ozone into the effluent. This study includes the effect of various parameters such as inlet ozone dose, pH of solution and initial concentration of dye on decolorization of dye in terms CRE. The maximum CRE of 98.62% with the reaction rate constant of 0.26 min-1 is achieved in 18 minutes of reaction time at inlet ozone dose of 11.5 g/m3, solution pH of 11 and 30 mg/L of initial concentration of dye. The presence of radical scavenger (Tertiary Butyl Alcohol) suppressed the CRE from 98.62% to 95.4% at high pH values indicates that the indirect mechanism dominates due to the presence of hydroxyl radicals which are formed by the decomposition of ozone. The diffusive and convective mass transfer coefficients of ozone are calculated as 1.78 × 10-5 cm2/sec and 0.075 min-1. It is observed that the fraction of resistance offered by liquid is very much high compared to gas phase indicates that the ozonation is a liquid phase mass transfer controlled operation.

Contributions of foreign, domestic and natural emissions to US ozone estimated using the path-integral method in CAMx nested within GEOS-Chem

Directory of Open Access Journals (Sweden)

A. M. Dunker

2017-10-01

Full Text Available The Goddard Earth Observing System global chemical transport (GEOS-Chem model was used at 2°  ×  2.5° resolution to simulate ozone formation for a base case representing year 2010 and a natural background case without worldwide anthropogenic emissions. These simulations provided boundary concentrations for base and natural background simulations with the Comprehensive Air Quality Model with Extensions (CAMx on a North American domain (one-way nested at 12 km  ×  12 km resolution over March–September 2010. The predicted maximum daily average 8 h (MDA8 background ozone for the US is largest in the mountainous areas of Colorado, New Mexico, Arizona, and California. The background MDA8 ozone in some of these locations exceeds 60 ppb, when averaged over the 10 days with the largest base-case ozone (T10base average. The background ozone generally becomes both a larger fraction of the base-case ozone in the western US and a smaller fraction in the eastern US when proceeding from spring to summer to the T10base average. The ozone difference between the base and background cases represents the increment to ozone from all anthropogenic sources. The path-integral method was applied to allocate this anthropogenic ozone increment to US anthropogenic emissions, Canadian/Mexican anthropogenic emissions, and the anthropogenic components of the lateral and top boundary concentrations (BCs. Using the T10base average MDA8 ozone, the relative importance of the sources is generally US emissions  >  anthropogenic lateral BCs  >  Canadian/Mexican emissions  ≫  anthropogenic top BCs. Specifically, for 10 US urban areas, the source contributions were 12–53 ppb for US emissions, 3–9 ppb for lateral BCs, 0.2–3 ppb for Canadian/Mexican emissions, and  ≤  0.1 ppb for top BCs. The contributions of the lateral BCs are largest for the higher-elevation US sites in the Intermountain West and along the

Video-documentation: 'The Pannonic ozon project'

International Nuclear Information System (INIS)

Loibl, W.; Cabela, E.; Mayer, H. F.; Schmidt, M.

1998-07-01

Goal of the project was the production of a video film as documentation of the Pannonian Ozone Project- POP. The main part of the video describes the POP-model consisting of the modules meteorology, emissions and chemistry, developed during the POP-project. The model considers the European emission patterns of ozone precursors and the actual wind fields. It calculates ozone build up and depletion within air parcels due to emission and weather situation along trajectory routes. Actual ozone concentrations are calculated during model runs simulating the photochemical processes within air parcels moving along 4 day trajectories before reaching the Vienna region. The model computations were validated during extensive ground and aircraft-based measurements of ozone precursors and ozone concentration within the POP study area. Scenario computations were used to determine how much ozone can be reduced in north-eastern Austria by emissions control measures. The video lasts 12:20 minutes and consists of computer animations and life video scenes, presenting the ozone problem in general, the POP model and the model results. The video was produced in co-operation by the Austrian Research Center Seibersdorf - Department of Environmental Planning (ARCS) and Joanneum Research - Institute of Informationsystems (JR). ARCS was responsible for idea, concept, storyboard and text while JR was responsible for computer animation and general video production. The speaker text was written with scientific advice by the POP - project partners: Institute of Meteorology and Physics, University of Agricultural Sciences- Vienna, Environment Agency Austria - Air Quality Department, Austrian Research Center Seibersdorf- Environmental Planning Department/System Research Division. The film was produced as German and English version. (author)

Multi sensor reanalysis of total ozone

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R. J. van der A

2010-11-01

Full Text Available A single coherent total ozone dataset, called the Multi Sensor Reanalysis (MSR, has been created from all available ozone column data measured by polar orbiting satellites in the near-ultraviolet Huggins band in the last thirty years. Fourteen total ozone satellite retrieval datasets from the instruments TOMS (on the satellites Nimbus-7 and Earth Probe, SBUV (Nimbus-7, NOAA-9, NOAA-11 and NOAA-16, GOME (ERS-2, SCIAMACHY (Envisat, OMI (EOS-Aura, and GOME-2 (Metop-A have been used in the MSR. As first step a bias correction scheme is applied to all satellite observations, based on independent ground-based total ozone data from the World Ozone and Ultraviolet Data Center. The correction is a function of solar zenith angle, viewing angle, time (trend, and effective ozone temperature. As second step data assimilation was applied to create a global dataset of total ozone analyses. The data assimilation method is a sub-optimal implementation of the Kalman filter technique, and is based on a chemical transport model driven by ECMWF meteorological fields. The chemical transport model provides a detailed description of (stratospheric transport and uses parameterisations for gas-phase and ozone hole chemistry. The MSR dataset results from a 30-year data assimilation run with the 14 corrected satellite datasets as input, and is available on a grid of 1× 1 1/2° with a sample frequency of 6 h for the complete time period (1978–2008. The Observation-minus-Analysis (OmA statistics show that the bias of the MSR analyses is less than 1% with an RMS standard deviation of about 2% as compared to the corrected satellite observations used.

Elevation of telomerase activity in chronic radiation ulcer of human skin

International Nuclear Information System (INIS)

Li Xiaoying; Zhao Po; Wang Dewen; Yang Zhixiang

1997-01-01

Objective: To investigate the levels of telomerase activity in chronic radiation ulcers of human skin and the possible relationship between the enzyme and cancer transformation. Method: Using nonisotopic telomere repeat amplification protocol (TRAP), detections were performed in 20 cases of chronic radiation ulcers of human skin, 5 cases of normal skin tissues and 5 cases of carcinoma. Results: The positive rates for telomerase activity were 30.0%(6/20), 0(0/5) and 100%(5/5) in chronic radiation ulcers of human skin, normal skin and carcinoma, respectively. The telomerase activity in radiation ulcer was weaker than in carcinoma. Conclusion: The telomerase activity assay might be used as a marker for predicting the prognosis and the effect of treatment in chronic radiation ulcer of human skin

Exposure-Relevant Ozone Chemistry in Occupied Spaces

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-01

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

Effect of coupled anthropogenic perturbations on stratospheric ozone

International Nuclear Information System (INIS)

Wuebbles, D.J.; Luther, F.M.; Penner, J.E.

1992-01-01

Since 1976 the greatest concern about potential perturbations to stratospheric ozone has been in regard to the atmospheric release of chlorofluorocarbons. Consequently, atmospheric measurements of ozone have usually been compared with model calculations in which only chlorocarbon perturbations are considered. However, in order to compare theoretical calculations with recent measurements of ozone and to project expected changes to atmospheric ozone levels over the next few decades, one must consider the effect from other perturbations as well. In this paper, the authors consider the coupling between several possible anthropogenic atmospheric perturbations. Namely, they examine the effects of past and possible future increases of chlorocarbons, CO 2 , N 2 O, and NO x . The focus of these calculations is on the potential changes in ozone due to chlorocarbon emissions, how other anthropogenic perturbations may have influenced the actual change in ozone over the last decade, and how these perturbations may influence future changes in ozone. Although calculations including future chlorocarbon emissions alone result in significant reductions in ozone, there is very little change in total ozone over the coming decades when other anthropogenic sources are included. Increasing CO 2 concentrations have the largest offsetting effect on the change in total ozone due to chlorocarbons. Owing to the necessity of considering emissions from a number of trace gases simultaneously, determining expected global-scale chemical and climatic effects is more complex than was previously recognized

Elevated [11C]-D-Deprenyl Uptake in Chronic Whiplash Associated Disorder Suggests Persistent Musculoskeletal Inflammation

Science.gov (United States)

Linnman, Clas; Appel, Lieuwe; Fredrikson, Mats; Gordh, Torsten; Söderlund, Anne; Långström, Bengt; Engler, Henry

2011-01-01

There are few diagnostic tools for chronic musculoskeletal pain as structural imaging methods seldom reveal pathological alterations. This is especially true for Whiplash Associated Disorder, for which physical signs of persistent injuries to the neck have yet to be established. Here, we sought to visualize inflammatory processes in the neck region by means Positron Emission Tomography using the tracer 11C-D-deprenyl, a potential marker for inflammation. Twenty-two patients with enduring pain after a rear impact car accident (Whiplash Associated Disorder grade II) and 14 healthy controls were investigated. Patients displayed significantly elevated tracer uptake in the neck, particularly in regions around the spineous process of the second cervical vertebra. This suggests that whiplash patients have signs of local persistent peripheral tissue inflammation, which may potentially serve as a diagnostic biomarker. The present investigation demonstrates that painful processes in the periphery can be objectively visualized and quantified with PET and that 11C-D-deprenyl is a promising tracer for these purposes. PMID:21541010

Elevated [11C]-D-deprenyl uptake in chronic Whiplash Associated Disorder suggests persistent musculoskeletal inflammation.

Directory of Open Access Journals (Sweden)

Clas Linnman

Full Text Available There are few diagnostic tools for chronic musculoskeletal pain as structural imaging methods seldom reveal pathological alterations. This is especially true for Whiplash Associated Disorder, for which physical signs of persistent injuries to the neck have yet to be established. Here, we sought to visualize inflammatory processes in the neck region by means Positron Emission Tomography using the tracer (11C-D-deprenyl, a potential marker for inflammation. Twenty-two patients with enduring pain after a rear impact car accident (Whiplash Associated Disorder grade II and 14 healthy controls were investigated. Patients displayed significantly elevated tracer uptake in the neck, particularly in regions around the spineous process of the second cervical vertebra. This suggests that whiplash patients have signs of local persistent peripheral tissue inflammation, which may potentially serve as a diagnostic biomarker. The present investigation demonstrates that painful processes in the periphery can be objectively visualized and quantified with PET and that (11C-D-deprenyl is a promising tracer for these purposes.

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

Science.gov (United States)

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

2017-07-01

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

Improvements in Total Column Ozone in GEOSCCM and Comparisons with a New Ozone-Depleting Substances Scenario

Science.gov (United States)

Oman, Luke D.; Douglass, Anne R.

2014-01-01

The evolution of ozone is examined in the latest version of the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM) using old and new ozone-depleting substances (ODS) scenarios. This version of GEOSCCM includes a representation of the quasi-biennial oscillation, a more realistic implementation of ozone chemistry at high solar zenith angles, an improved air/sea roughness parameterization, and an extra 5 parts per trillion of CH3Br to account for brominated very short-lived substances. Together these additions improve the representation of ozone compared to observations. This improved version of GEOSCCM was used to simulate the ozone evolution for the A1 2010 and the newStratosphere-troposphere Processes and their Role in Climate (SPARC) 2013 ODS scenario derived using the SPARC Lifetimes Report 2013. This new ODS scenario results in a maximum Cltot increase of 65 parts per trillion by volume (pptv), decreasing slightly to 60 pptv by 2100. Approximately 72% of the increase is due to the longer lifetime of CFC-11. The quasi-global (60degS-60degN) total column ozone difference is relatively small and less than 1Dobson unit on average and consistent with the 3-4% larger 2050-2080 average Cly in the new SPARC 2013 scenario. Over high latitudes, this small change in Cly compared to the relatively large natural variabilitymakes it not possible to discern a significant impact on ozone in the second half of the 21st century in a single set of simulations.

Reduction of date microbial load with ozone

Science.gov (United States)

Farajzadeh, Davood; Qorbanpoor, Ali; Rafati, Hasan; Isfeedvajani, Mohsen Saberi

2013-01-01

Background: Date is one of the foodstuffs that are produced in tropical areas and used worldwide. Conventionally, methyl bromide and phosphine are used for date disinfection. The toxic side effects of these usual disinfectants have led food scientists to consider safer agents such as ozone for disinfection, because food safety is a top priority. The present study was performed to investigate the possibility of replacing common conventional disinfectants with ozone for date disinfection and microbial load reduction. Materials and Methods: In this experimental study, date samples were ozonized for 3 and 5 hours with 5 and 10 g/h concentrations and packed. Ozonized samples were divided into two groups and kept in an incubator which was maintained at 25°C and 40°C for 9 months. During this period, every 3 month, microbial load (bacteria, mold, and yeast) were examined in ozonized and non-ozonized samples. Results: This study showed that ozonization with 5 g/h for 3 hours, 5 g/h for 5 hours, 10 g/h for 3 hours, and 10 g/h for 5 hours leads to about 25%, 25%, 53%, and 46% reduction in date mold and yeast load and about 6%, 9%, 76%, and 74.7% reduction in date bacterial load at baseline phase, respectively. Appropriate concentration and duration of ozonization for microbial load reduction were 10 g/h and 3 hours. Conclusion: Date ozonization is an appropriate method for microbial load reduction and leads to an increase in the shelf life of dates. PMID:24124432

Ground-level ozone: Our new environmental policy

International Nuclear Information System (INIS)

Schiff, H.

1991-01-01

The environmental problem of ground level ozone is discussed, and the Canadian strategy for dealing with it is explained. Ozone in the troposphere can cause serious health problems in susceptible persons, and is estimated to cause up to $70 million in crop damage per year. The Canadian Council of Ministers of the Environment (CCME) Plan calls for less than 82 ppB by volume of ozone in any one-hour period in all areas of Canada by 2005. Three areas of Canada regularly exceed this value: the Lower Frazer valley in British Columbia, Saint John in New Brunswick, and the Windsor-Quebec corridor along the lower Great Lakes and the St. Lawrence River. Ozone is formed by a photochemical reaction of ammonia gases, nitrogen oxides, hydrogen sulfide or sulfur dioxide. Historically, ozone control has concentrated on controlling hydrocarbon emissions, but to little effect. In most locations close to large cities, ozone production is nitrogen oxide-limited, and the most recent models predict that the best strategy for ozone reduction requires the simultaneous reduction of both hydrocarbons and nitrogen oxides. The CCME Management Plan suggests that the 82 ppB ozone target will require a reduction of 40-50% in nitrogen oxide emissions. The Windsor end of the Windsor-Quebec corridor is dominated by transport of ozone and precursors from the USA, particularly Detroit and Cleveland, so Canadian controls alone are unlikely to solve the problem. For the rest of the corridor, nitrogen oxide control is likely to be most effective in urban areas. 1 fig

Investigating Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range Transport

Science.gov (United States)

Ryoo, Ju-Mee; Johnson, Matthew S.; Iraci, Laura T.; Yates, Emma L.; Pierce, R. Bradley; Tanaka, Tomoaki; Gore, Warren

2016-01-01

High ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOSchem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7% and 7.6%, respectively) compared to that from LT (64.1%), but the relative ozone concentration coming from LS and UT is high (38.4% and 20.95%, respectively) compared to that from LT (17.7%). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.

Ozone sensitivity of plants in natural communities