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Sample records for increases ozone pollution

  1. Tropospheric Ozone Increases over the Southern Africa Region: Bellwether for Rapid Growth in Southern Hemisphere Pollution?

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  2. China's air pollution reduction efforts may result in an increase in surface ozone levels in highly polluted areas.

    PubMed

    Anger, Annela; Dessens, Olivier; Xi, Fengming; Barker, Terry; Wu, Rui

    2016-03-01

    China, as a fast growing fossil-fuel-based economy, experiences increasing levels of air pollution. To tackle air pollution, China has taken the first steps by setting emission-reduction targets for nitrogen oxides (NO x ) and sulphur dioxide (SO2) in the 11th and 12th Five Year Plans. This paper uses two models-the Energy-Environment-Economy Model at the Global level (E3MG) and the global Chemistry Transport Model pTOMCAT-to test the effects of these policies. If the policy targets are met, then the maximum values of 32 % and 45 % reductions below 'business as usual' in the monthly mean NO x and SO2 concentrations, respectively, will be achieved in 2015. However, a decrease in NO x concentrations in some highly polluted areas of East, North-East and South-East China can lead to up to a 10% increase in the monthly mean concentrations in surface ozone in 2015. Our study demonstrates an urgent need for the more detailed analysis of the impacts and designs of air pollution reduction guidelines for China.

  3. China's air pollution reduction efforts may result in an increase in surface ozone levels in highly polluted areas.

    PubMed

    Anger, Annela; Dessens, Olivier; Xi, Fengming; Barker, Terry; Wu, Rui

    2016-03-01

    China, as a fast growing fossil-fuel-based economy, experiences increasing levels of air pollution. To tackle air pollution, China has taken the first steps by setting emission-reduction targets for nitrogen oxides (NO x ) and sulphur dioxide (SO2) in the 11th and 12th Five Year Plans. This paper uses two models-the Energy-Environment-Economy Model at the Global level (E3MG) and the global Chemistry Transport Model pTOMCAT-to test the effects of these policies. If the policy targets are met, then the maximum values of 32 % and 45 % reductions below 'business as usual' in the monthly mean NO x and SO2 concentrations, respectively, will be achieved in 2015. However, a decrease in NO x concentrations in some highly polluted areas of East, North-East and South-East China can lead to up to a 10% increase in the monthly mean concentrations in surface ozone in 2015. Our study demonstrates an urgent need for the more detailed analysis of the impacts and designs of air pollution reduction guidelines for China. PMID:26409886

  4. Has the sensitivity of soybean cultivars to ozone pollution increased with time? An analysis of published dose-response data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rising trend in concentrations of ground-level ozone (O3) – a common air pollutant and phytotoxin – currently being experienced in some world regions represents a threat to agricultural yield. Soybean (Glycine max (L.) Merr.) is an O3-sensitive crop species, and is experiencing increasing globa...

  5. Kudzu (Pueraria montana) invasion doubles emissions of nitric oxide and increases ozone pollution.

    PubMed

    Hickman, Jonathan E; Wu, Shiliang; Mickley, Loretta J; Lerdau, Manuel T

    2010-06-01

    The nitrogen-fixing legume kudzu (Pueraria montana) is a widespread invasive plant in the southeastern United States with physiological traits that may lead to important impacts on ecosystems and the atmosphere. Its spread has the potential to raise ozone levels in the region by increasing nitric oxide (NO) emissions from soils as a consequence of increasing nitrogen (N) inputs and cycling in soils. We studied the effects of kudzu invasions on soils and trace N gas emissions at three sites in Madison County, Georgia in 2007 and used the results to model the effects of kudzu invasion on regional air quality. We found that rates of net N mineralization increased by up to 1,000%, and net nitrification increased by up to 500% in invaded soils in Georgia. Nitric oxide emissions from invaded soils were more than 100% higher (2.81 vs. 1.24 ng NO-N cm(-2) h(-1)). We used the GEOS-Chem chemical transport model to evaluate the potential impact of kudzu invasion on regional atmospheric chemistry and air quality. In an extreme scenario, extensive kudzu invasion leads directly to an increase in the number of high ozone events (above 70 ppb) of up to 7 days each summer in some areas, up from 10 to 20 days in a control scenario with no kudzu invasion. These results establish a quantitative link between a biological invasion and ozone formation and suggest that in this extreme scenario, kudzu invasion can overcome some of the air quality benefits of legislative control.

  6. Has the sensitivity of soybean cultivars to ozone pollution increased with time? An analysis of published dose-response data.

    PubMed

    Osborne, Stephanie A; Mills, Gina; Hayes, Felicity; Ainsworth, Elizabeth A; Büker, Patrick; Emberson, Lisa

    2016-09-01

    The rising trend in concentrations of ground-level ozone (O3 ) - a common air pollutant and phytotoxin - currently being experienced in some world regions represents a threat to agricultural yield. Soybean (Glycine max (L.) Merr.) is an O3 -sensitive crop species and is experiencing increasing global demand as a dietary protein source and constituent of livestock feed. In this study, we collate O3 exposure-yield data for 49 soybean cultivars, from 28 experimental studies published between 1982 and 2014, to produce an updated dose-response function for soybean. Different cultivars were seen to vary considerably in their sensitivity to O3 , with estimated yield loss due to O3 ranging from 13.3% for the least sensitive cultivar to 37.9% for the most sensitive, at a 7-h mean O3 concentration (M7) of 55 ppb - a level frequently observed in regions of the USA, India and China in recent years. The year of cultivar release, country of data collection and type of O3 exposure used were all important explanatory variables in a multivariate regression model describing soybean yield response to O3 . The data show that the O3 sensitivity of soybean cultivars increased by an average of 32.5% between 1960 and 2000, suggesting that selective breeding strategies targeting high yield and high stomatal conductance may have inadvertently selected for greater O3 sensitivity over time. Higher sensitivity was observed in data from India and China compared to the USA, although it is difficult to determine whether this effect is the result of differential cultivar physiology, or related to local environmental factors such as co-occurring pollutants. Gaining further understanding of the underlying mechanisms that govern the sensitivity of soybean cultivars to O3 will be important in shaping future strategies for breeding O3 -tolerant cultivars. PMID:27082950

  7. Foreign versus Domestic Contributions to China's Ozone Air Pollution

    NASA Astrophysics Data System (ADS)

    Ni, Ruijing; Lin, Jintai; Lin, Weili; Yan, Yingying

    2016-04-01

    Ozone is a critical air pollutant because it damages human health and vegetation. Previous studies for the United States and Europe have shown large influences of foreign emissions on domestic ozone levels, whereas the relative contributions of foreign versus domestic emissions are much less clear for China' ozone pollution. Here, we use the global chemical transport model (GEOS-Chem) simulations to quantify the contributions of ozone transport from regions with large anthropogenic emissions to China. Our results indicate considerable influences of foreign anthropogenic pollution on China's ozone air quality. Of all ozone over China produced by global anthropogenic emissions, foreign anthropogenic emissions contribute 40% near the surface, and the foreign contribution increases with altitude and reaches up to 70% in the upper troposphere. The contributions by North America and Europe reach maximum levels in spring, in which season Chinese influence on the western United States also peaks. The springtime maxima are associated with strong westerly winds and frequent cyclonic activities favorable to the long-range transport. European anthropogenic pollution enhanced surface ozone concentrations by 1~4 ppbv over Western and Northern China in spring and winter. Despite much longer transport distance, the contribution from North America is distinctly greater than that from Europe due to the nearly tripled VOC emissions. Ozone contributed by Foreign Asian countries peaks in summer and autumn, widely dispersed to the upper troposphere over Southern China with strong upwelling. Therefore, although China produces large amounts of ozone precursor emissions, its domestic ozone pollution is still contributed significantly by foreign anthropogenic emissions. Our study is relevant to Chinese ozone pollution control and global collaboration.

  8. Increasing external effects negate local efforts to control ozone air pollution: a case study of Hong Kong and implications for other Chinese cities.

    PubMed

    Xue, Likun; Wang, Tao; Louie, Peter K K; Luk, Connie W Y; Blake, Donald R; Xu, Zheng

    2014-09-16

    It is challenging to reduce ground-level ozone (O3) pollution at a given locale, due in part to the contributions of both local and distant sources. We present direct evidence that the increasing regional effects have negated local control efforts for O3 pollution in Hong Kong over the past decade, by analyzing the daily maximum 8 h average O3 and Ox (=O3+NO2) concentrations observed during the high O3 season (September-November) at Air Quality Monitoring Stations. The locally produced Ox showed a statistically significant decreasing trend over 2002-2013 in Hong Kong. Analysis by an observation-based model confirms this decline in in situ Ox production, which is attributable to a reduction in aromatic hydrocarbons. However, the regional background Ox transported into Hong Kong has increased more significantly during the same period, reflecting contributions from southern/eastern China. The combined result is a rise in O3 and a nondecrease in Ox. This study highlights the urgent need for close cross-boundary cooperation to mitigate the O3 problem in Hong Kong. China's air pollution control policy applies primarily to its large cities, with little attention to developing areas elsewhere. The experience of Hong Kong suggests that this control policy does not effectively address secondary pollution, and that a coordinated multiregional program is required.

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

    NASA Astrophysics Data System (ADS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Vergne, Phillippe; Sifakis, Nicolas; Sanz, María José; Rasmussen, Stine; Ro-Poulsen, Helge; Ribas, Àngela; Peñuelas, Josep; Kambezidis, Harry; He, Shang; Garrec, Jean Pierre; Calatayud, Vicent

    Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic-exposed sites. The tobacco plants were exposed to ambient air for biweekly periods at up to 100 biomonitoring sites from 2000 to 2002. Special emphasis was placed upon methodological standardisation of plant cultivation, field exposure and injury assessment. Ozone-induced leaf injury showed a clearly increasing gradient from northern and northwestern Europe to central and southern European locations. The strongest ozone impact occurred at the exposure sites in Lyon and Barcelona, while in Edinburgh, Sheffield, Copenhagen and Düsseldorf only weak to moderate ozone effects were registered. Between-site differences 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. This is because the actual ozone flux into the leaf, which is modified by various environmental factors, rather than ambient ozone concentration determines the effects on plants. The advantage of sensitive bioindicators like tobacco Bel-W3 is that the impact of the effectively absorbed ozone dose can directly be measured.

  10. [Ozone decline and UV increase].

    PubMed

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm).

  11. [Ozone decline and UV increase].

    PubMed

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm). PMID:14770335

  12. The impacts of surface ozone pollution on winter wheat productivity in China--An econometric approach.

    PubMed

    Yi, Fujin; Jiang, Fei; Zhong, Funing; Zhou, Xun; Ding, Aijun

    2016-01-01

    The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply.

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

    NASA Technical Reports Server (NTRS)

    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

  14. Ozone pollution: What can we see from space? A case study

    NASA Astrophysics Data System (ADS)

    Foret, G.; Eremenko, M.; Cuesta, J.; Sellitto, P.; Barré, J.; Gaubert, B.; Coman, A.; Dufour, G.; Liu, X.; Joly, M.; Doche, C.; Beekmann, M.

    2014-07-01

    Due to its impact on environment, tropospheric ozone received particular attention since several decades. Ground-based networks associated with regional chemical transport models are used to monitor and forecast surface ozone concentrations, but coverage, representativeness, and accuracy issues remain important. Recent satellite observations have demonstrated the capacity to probe tropospheric ozone, but there has been no explicit attempt to quantify their ability to measure ozone pollution near ground. We propose here to assess the ability of ozone sounders to detect a photochemical ozone pollution event that is supposed to be a favorable situation for satellite detection. We have chosen ozone pollution event over Europe associated with a warm conveyor belt that efficiently transports photochemically produced ozone upward. Ozone satellite products from Global Ozone Monitoring Experiment-2, Infrared Atmospheric Sounding Interferometer (IASI), and Ozone Monitoring Instrument are analyzed here for their capacity to capture such an event. Also, in situ observations and regional chemical-transport models show increasing ozone concentrations in the continental and Mediterranean boundary layer and further transport to central Europe and Scandinavia associated with upward transport. Satellite observations do not detect high ozone concentrations within the boundary layer due the weak sensitivity near the surface. Nevertheless, we have shown that the IR sounder IASI was able to detect, qualitatively and quantitatively, the ozone plume transported upward by the warm conveyor belt, suggesting that a quantification of upward transport of ozone pollution could be possible using current satellite observations. This should encourage us to further explore approaches more sensitive to surface ozone (such as the multispectral approach) and to prepare the next generation of still more sensitive spaceborne instruments.

  15. Increasing Springtime Ozone Mixing Ratios in the Free Troposphere Over Western North America

    NASA Technical Reports Server (NTRS)

    Cooper, O. R.; Parrish, D. D.; Stohl, A.; Trainer, M.; Nedelec, P.; Thouret, V.; Cammas, J. P.; Oltmans, S. J.; Johnson, B. J.; Tarasick, D.; Leblanc, T.; McDermid, I. S.; Jaffe, D.; Gao, R.; Stith, J.; Ryerson, T.; Aikin, K.; Campos, T.; Weinheimer, A.; Avery, M. A.

    2010-01-01

    In the lowermost layer of the atmosphere - the troposphere - ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity1. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA s compliance with its ozone air quality standard.

  16. Increasing springtime ozone mixing ratios in the free troposphere over western North America.

    PubMed

    Cooper, O R; Parrish, D D; Stohl, A; Trainer, M; Nédélec, P; Thouret, V; Cammas, J P; Oltmans, S J; Johnson, B J; Tarasick, D; Leblanc, T; McDermid, I S; Jaffe, D; Gao, R; Stith, J; Ryerson, T; Aikin, K; Campos, T; Weinheimer, A; Avery, M A

    2010-01-21

    In the lowermost layer of the atmosphere-the troposphere-ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA's compliance with its ozone air quality standard.

  17. Exacerbations of childhood asthma and ozone pollution in Atlanta

    SciTech Connect

    White, M.C.; Etzel, R.A.; Lloyd, C. ); Wilcox, W.D. )

    1994-04-01

    Asthma prevalence and mortality due to asthma have been increasing during the last decade, and both the rates and the increases in rates have been higher for blacks than whites and higher for children than adults. Whether environmental factors such as air pollution contribute to these increases is unknown. The purpose of this study was to examine the relationship between emergency visits to a hospital for childhood asthma and exposure to ozone in an indigent, predominantly black population. Data were collected by abstracting clinical records for all children with asthma or reactive airway disease in one public hospital during the summer of 1990. From June 1, 1990, to August 31, 1990, 609 visits were made by children aged 1 to 16 years to an emergency clinic for treatment of asthma or reactive airway disease. Monitoring data indicated that maximum ozone levels equalled or exceeded 0.11 ppm on 6 days during the study period. The average number of visits for asthma or reactive airway disease was 37% higher on the days after those 6 days (from 6:00 PM to 6:00 PM the next day) than on other days (95% Cl, RR = 1.02-1.73). The results of the study suggest that among black children from low-income families, asthma may be exacerbated following periods of high ozone pollution. 45 refs., 1 fig., 4 tabs.

  18. Atmospheric ozone and man-made pollution.

    PubMed

    Fabian, P

    1976-06-01

    Atmospheric photochemistry and transport processes, related to the ozone layer, are discussed. Natural or man-made changes of the biosphere, variations of radiation, or general circulation as well as anthropogenic release of ozone-destroying catalysts are likely to alter the earth's ozone shield. The possible effects of ozone depletion caused by supersonic aircraft, nuclear weapons, nitrogen fertilizers, and chlorofluoromethanes are discussed.

  19. Impacts of increasing ozone on Indian plants.

    PubMed

    Oksanen, E; Pandey, V; Pandey, A K; Keski-Saari, S; Kontunen-Soppela, S; Sharma, C

    2013-06-01

    Increasing anthropogenic and biogenic emissions of precursor compounds have led to high tropospheric ozone concentrations in India particularly in Indo-Gangetic Plains, which is the most fertile and cultivated area of this rapidly developing country. Current ozone risk models, based on European and North American data, provide inaccurate estimations for crop losses in India. During the past decade, several ozone experiments have been conducted with the most important Indian crop species (e.g. wheat, rice, mustard, mung bean). Experimental work started in natural field conditions around Varanasi area in early 2000's, and the use of open top chambers and EDU (ethylene diurea) applications has now facilitated more advanced studies e.g. for intra-species sensitivity screening and mechanisms of tolerance. In this review, we identify and discuss the most important gaps of knowledge and future needs of action, e.g. more systematic nationwide monitoring for precursor and ozone formation over Indian region.

  20. Discoveries about Tropospheric Ozone Pollution from Satellite and Sounding

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2004-01-01

    We have been producing near-real time tropospheric ozone satellite maps from the TOMS (Total Ozone Mapping Spectrometer) sensor since 1997. This is most readily done for the tropics, where the stratospheric and tropospheric ozone column amounts can be discriminated readily. Maps for 1996-2000 for the operational Earth-Probe instrument reside at: chttp://www.atmos.umd.edu/-trope>. Pollution in the tropics is influenced by biomass burning and by transport patterns that favor recirculation and in other cases reflect climate variability like the El-Nino-Southern Oscillation [Thompson et al., 2001]. Time permitting, examples of mid-latitude, intercontinental transport of ozone pollution sensed by TOMS will be shown. The satellite view of chemical-dynamical interactions in tropospheric ozone is not adequate to capture vertical variability. Thus, in 1998, NASA's Goddard Space Flight Center and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches and provides a public archive of ozonesonde data from twelve tropical stations at http://croc.gsfc.nasa.gov/shadoz. Further insights into the role of chemical and dynamical influences have emerged from the first 4-5 years of SHADOZ data (less than 2000 ozone profiles): (a) highly variable tropospheric ozone; (b) a zonal wave-one pattern in tropospheric column ozone; (c) convective variability affects tropospheric ozone over the Indian and Pacific Ocean; (d) a "tropical Atlantic Paradox" appears in December-January-February.

  1. Ozone

    MedlinePlus

    ... reactive form of oxygen. In the upper atmosphere, ozone forms a protective layer that shields us from the sun’s ultraviolet rays. At ground level, ozone is a harmful air pollutant and a primary ...

  2. Discoveries about Tropospheric Ozone Pollution from Satellite and Soundings

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2004-01-01

    We have been producing near-red time tropospheric ozone satellite maps from the TOMS (Total Ozone Mapping Spectrometer) sensor since 1997. Maps for 1996-2000 for the operational Earth-Probe instrument are at:. Pollution in the tropics is influenced by biomass burning and by transport patterns that favor recirculation and in other cases reflect climate variability like the El-Nino-Southern Oscillation [Thompson et al., 2001]. The satellite view of chemical-dynamical interactions in tropospheric ozone is not adequate to capture vertical gradients in pollution. Thus, in 1998, NASA's Goddard Space Flight Center and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches and provides a public archive of ozonesonde data from twelve tropical stations at http://croc.gsfc.nasa.gov/shadoz. Further insights into the role of chemical and dynamical influences have emerged from the first 4-5 years of SHADOZ data (more than 2000 ozone profiles). Highly variable tropospheric ozone and a zonal wave-one pattern in tropospheric ozone suggest that dynamics is as important as pollution in determining tropical ozone distributions.

  3. Ozone Exposure Increases Circulating Stress Hormones and Lipid Metabolites in Humans

    EPA Science Inventory

    RATIONALE: Air pollution has been associated with increased prevalence of type 2 diabetes; however, the mechanisms remain unknown. We have shown that acute ozone exposure in rats induces release of stress hormones, hyperglycemia, leptinemia, and gluoose intolerance that are assoc...

  4. East China plains: a "basin" of ozone pollution.

    PubMed

    Zhao, Chun; Wang, Yuhang; Zeng, Tao

    2009-03-15

    Economic growth and associated pollution emissions in China are concentrated over three connected plains to the east In this work, we analyze an episode of highly elevated ozone over East China on June 9-14, 2004, using a 3-D chemical transport model. During this episode, the East China plains were under a high-pressure system, which suppressed the ventilation of pollutants from the boundary layer. Simulated ozone concentrations over a major fraction of East China reached high levels, all the way down to the Pearl River Delta region in the southern border. The convergence of pollutant emissions and population over the vast stretch of the geographically flat plains of East China makes the region susceptible to high-ozone exposure. During this episode, the high-03 region extended over an area >1 million km2, which hosts a population of >800 million people. Model results indicate that controlling anthropogenic NOx emissions effectively reduces the area with high-ozone exposure.

  5. Solar photo-ozonation: A novel treatment method for the degradation of water pollutants.

    PubMed

    Chávez, Ana M; Rey, Ana; Beltrán, Fernando J; Álvarez, Pedro M

    2016-11-01

    The decomposition of aqueous ozone by UV-vis radiation has been investigated with focus on the impact of ozone photolysis on the degradation of water pollutants during solar ozonation processes. The apparent first-order rate constants of the decomposition of ozone (kobs) have been determined at various pHs in the 4-9 range using radiation of different wavelengths in the UV-vis range. It was found that UVA-visible radiation (λ>320nm) highly enhanced ozone decomposition, especially at pH 4, for which kobs was three-folded with respect to the process in the absence of radiation. Hydrogen peroxide was identified as a main intermediate of ozone photo-decomposition at pH 4. Experiments of degradation of oxalic acid by ozone showed that solar irradiation brings about an increase in the hydroxyl radical to ozone exposures ratio (Rct). Finally, photo-ozonation (λ>300nm) was shown advantageous over single ozonation in the mineralization of a selection of emerging contaminants (metoprolol, ibuprofen, N,N-diethyl-meta-toluamide and clofibric acid) in both ultrapure water and a synthetic secondary effluent. Thus, TOC removal in 2-h treatments increased from 10 to 25% in the absence of radiation to about 50% in the presence of radiation.

  6. Solar photo-ozonation: A novel treatment method for the degradation of water pollutants.

    PubMed

    Chávez, Ana M; Rey, Ana; Beltrán, Fernando J; Álvarez, Pedro M

    2016-11-01

    The decomposition of aqueous ozone by UV-vis radiation has been investigated with focus on the impact of ozone photolysis on the degradation of water pollutants during solar ozonation processes. The apparent first-order rate constants of the decomposition of ozone (kobs) have been determined at various pHs in the 4-9 range using radiation of different wavelengths in the UV-vis range. It was found that UVA-visible radiation (λ>320nm) highly enhanced ozone decomposition, especially at pH 4, for which kobs was three-folded with respect to the process in the absence of radiation. Hydrogen peroxide was identified as a main intermediate of ozone photo-decomposition at pH 4. Experiments of degradation of oxalic acid by ozone showed that solar irradiation brings about an increase in the hydroxyl radical to ozone exposures ratio (Rct). Finally, photo-ozonation (λ>300nm) was shown advantageous over single ozonation in the mineralization of a selection of emerging contaminants (metoprolol, ibuprofen, N,N-diethyl-meta-toluamide and clofibric acid) in both ultrapure water and a synthetic secondary effluent. Thus, TOC removal in 2-h treatments increased from 10 to 25% in the absence of radiation to about 50% in the presence of radiation. PMID:27258212

  7. [Effects of synoptic type on surface ozone pollution in Beijing].

    PubMed

    Tang, Gui-qian; Li, Xin; Wang, Xiao-ke; Xin, Jin-yuan; Hu, Bo; Wang, Li-li; Ren, Yu-fen; Wang, Yue-Si

    2010-03-01

    Ozone (O), influenced by meteorological factors, is a primary gaseous photochemical pollutant during summer to fall in Beijing' s urban ambient. Continuous monitoring during July to September in 2008 was carried out at four sites in Beijing. Analyzed with synoptic type, the results show that the ratios of pre-low cylonic (mainly Mongolia cyclone) and pre-high anticylonic to total weather conditions are about 42% and 20%, illustrating the high-and low-ozone episodes, respectively. At the pre-low cylonic conditions, high temperature, low humidity, mountain and valley winds caused by local circulation induce average hourly maximum ozone concentration (volume fraction) up to 102.2 x 10(-9), negative correlated with atmospheric pressure with a slope of -3.4 x 10(-9) Pa(-1). The time of mountain wind changed to valley wind dominates the diurnal time of maximum ozone, generally around 14:00. At the pre-high anticylonic conditions, low temperature, high humidity and systematic north wind induce average hourly maximum ozone concentration (volume fraction) only 49.3 x 10(-9), the diurnal time of maximum ozone is deferred by continuous north wind till about 16:00. The consistency of photochemical pollution in Beijing region shows that good correlation exists between synoptic type and ozone concentration. Therefore, getting an eye on the structure and evolution of synoptic type is of great significances for forecasting the photochemical pollution.

  8. Health Effects of Ozone and Particle Pollution

    MedlinePlus

    ... and air pollution . Disparities in the Impact of Air Pollution The burden of air pollution is not evenly shared. Poorer people and some ... exposure to pollutants. Learn more about disparities and air pollution . Living Near Highways Being in heavy traffic, or ...

  9. Role of tropospheric ozone increases in 20th-century climate change

    NASA Astrophysics Data System (ADS)

    Shindell, Drew; Faluvegi, Greg; Lacis, Andrew; Hansen, James; Ruedy, Reto; Aguilar, Elliot

    2006-04-01

    Human activities have increased tropospheric ozone, contributing to 20th-century warming. Using the spatial and temporal distribution of precursor emissions, we simulated tropospheric ozone from 1890 to 1990 using the NASA Goddard Institute for Space Studies (GISS) chemistry model. Archived three-dimensional ozone fields were then used in transient GISS climate model simulations. This enables more realistic evaluation of the impact of tropospheric ozone increases than prior simulations using an interpolation between preindustrial and present-day ozone. We find that tropospheric ozone contributed to the greater 20th-century warming in the Northern Hemisphere extratropics compared with the tropics and in the tropics compared with the Southern Hemisphere extratropics. Additionally, ozone increased more rapidly during the latter half of the century than the former, causing more rapid warming during that time. This is especially apparent in the tropics and is consistent with observations, which do not show similar behavior in the extratropics. Other climate forcings do not substantially accelerate warming rates in the tropics relative to other regions. This suggests that accelerated tropospheric ozone increases related to industrialization in the developing world have contributed to the accelerated tropical warming. During boreal summer, tropospheric ozone causes enhanced warming (>0.5°C) over polluted northern continental regions. Finally, the Arctic climate response to tropospheric ozone increases is large during fall, winter, and spring when ozone's lifetime is comparatively long and pollution transported from midlatitudes is abundant. The model indicates that tropospheric ozone could have contributed about 0.3°C annual average and about 0.4°C-0.5°C during winter and spring to the 20th-century Arctic warming. Pollution controls could thus substantially reduce the rapid rate of Arctic warming.

  10. Effect of naturally occurring ozone air pollution episodes on pulmonary oxidative stress and inflammation.

    PubMed

    Pirozzi, Cheryl; Sturrock, Anne; Weng, Hsin-Yi; Greene, Tom; Scholand, Mary Beth; Kanner, Richard; Paine, Robert

    2015-05-12

    This study aimed to determine if naturally occurring episodes of ozone air pollution in the Salt Lake Valley in Utah, USA, during the summer are associated with increased pulmonary inflammation and oxidative stress, increased respiratory symptoms, and decreased lung function in individuals with chronic obstructive pulmonary disease (COPD) compared to controls. We measured biomarkers (nitrite/nitrate (NOx), 8-isoprostane) in exhaled breath condensate (EBC), spirometry, and respiratory symptoms in 11 former smokers with moderate-to-severe COPD and nine former smokers without airflow obstruction during periods of low and high ozone air pollution. High ozone levels were associated with increased NOx in EBC in both COPD (8.7 (±8.5) vs. 28.6 (±17.6) μmol/L on clean air vs. pollution days, respectively, p < 0.01) and control participants (7.6 (±16.5) vs. 28.5 (±15.6) μmol/L on clean air vs. pollution days, respectively, p = 0.02). There was no difference in pollution effect between COPD and control groups, and no difference in EBC 8-isoprostane, pulmonary function, or respiratory symptoms between clean air and pollution days in either group. Former smokers both with and without airflow obstruction developed airway oxidative stress and inflammation in association with ozone air pollution episodes.

  11. Fate of specific pollutants during wet oxidation and ozonation

    SciTech Connect

    Baillod, C.R.; Faith, B.M.; Masi, O.

    1982-08-01

    The ability of wet oxidation and ozonation to destroy five typical priority pollutants (phenol, 2-chlorophenol, 1,2-dichloroethane, 4-nitrophenol, and dimethylphthalate) is reported. Particular attention has been paid to interpreting the batch kinetic data, exploring the influence of initial pH on ozonation and identifying and measuring the low-molecular weight organic acids produced. 28 references, 16 figures, 6 tables. (JMT)

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

    NASA Astrophysics Data System (ADS)

    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

  13. Increase in ozone due to the use of biodiesel fuel rather than diesel fuel.

    PubMed

    Thang, Phan Quang; Muto, Yusuke; Maeda, Yasuaki; Trung, Nguyen Quang; Itano, Yasuyuki; Takenaka, Norimichi

    2016-09-01

    The consumption of fuel by vehicles emits nitrogen oxides (NOx) and non-methane hydrocarbons (NMHCs) into the atmosphere, which are important ozone precursors. Ozone is formed as a secondary pollutant via photochemical processes and is not emitted directly into the atmosphere. In this paper, the ozone increase resulting from the use of biodiesel and diesel fuels was investigated, and the different ozone formation trends were experimentally evaluated. Known amounts of exhaust gas from a power generator operated using biodiesel and diesel fuels were added to ambient air. The quality of the ambient air, such as the initial NMHC and NOx concentrations, and the irradiation intensity have an effect on the ozone levels. When 30 cm(3) of biodiesel fuel exhaust gas (BFEG) or diesel fuel exhausted gas (DFEG) was added to 18 dm(3) of ambient air, the highest ratios of ozone increase from BFEG compared with DFEG in Japan and Vietnam were 31.2 and 42.8%, respectively, and the maximum ozone increases resulting from DFEG and BFEG compared with the ambient air in Japan were 17.4 and 26.4 ppb, respectively. The ozone increase resulting from the use of BFEG was large and significant compared to that from DFEG under all experimental conditions. The ozone concentration increased as the amount of added exhaust gas increased. The ozone increase from the Jatropha-BFEG was slightly higher than that from waste cooking oil-BFEG. PMID:27396671

  14. Increase in ozone due to the use of biodiesel fuel rather than diesel fuel.

    PubMed

    Thang, Phan Quang; Muto, Yusuke; Maeda, Yasuaki; Trung, Nguyen Quang; Itano, Yasuyuki; Takenaka, Norimichi

    2016-09-01

    The consumption of fuel by vehicles emits nitrogen oxides (NOx) and non-methane hydrocarbons (NMHCs) into the atmosphere, which are important ozone precursors. Ozone is formed as a secondary pollutant via photochemical processes and is not emitted directly into the atmosphere. In this paper, the ozone increase resulting from the use of biodiesel and diesel fuels was investigated, and the different ozone formation trends were experimentally evaluated. Known amounts of exhaust gas from a power generator operated using biodiesel and diesel fuels were added to ambient air. The quality of the ambient air, such as the initial NMHC and NOx concentrations, and the irradiation intensity have an effect on the ozone levels. When 30 cm(3) of biodiesel fuel exhaust gas (BFEG) or diesel fuel exhausted gas (DFEG) was added to 18 dm(3) of ambient air, the highest ratios of ozone increase from BFEG compared with DFEG in Japan and Vietnam were 31.2 and 42.8%, respectively, and the maximum ozone increases resulting from DFEG and BFEG compared with the ambient air in Japan were 17.4 and 26.4 ppb, respectively. The ozone increase resulting from the use of BFEG was large and significant compared to that from DFEG under all experimental conditions. The ozone concentration increased as the amount of added exhaust gas increased. The ozone increase from the Jatropha-BFEG was slightly higher than that from waste cooking oil-BFEG.

  15. High winter ozone pollution from carbonyl photolysis in an oil and gas basin

    NASA Astrophysics Data System (ADS)

    Edwards, Peter M.; Brown, Steven S.; Roberts, James M.; Ahmadov, Ravan; Banta, Robert M.; Degouw, Joost A.; Dubé, William P.; Field, Robert A.; Flynn, James H.; Gilman, Jessica B.; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O.; Lefer, Barry L.; Lerner, Brian M.; Li, Rui; Li, Shao-Meng; McKeen, Stuart A.; Murphy, Shane M.; Parrish, David D.; Senff, Christoph J.; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R.; Trainer, Michael K.; Tsai, Catalina; Veres, Patrick R.; Washenfelder, Rebecca A.; Warneke, Carsten; Wild, Robert J.; Young, Cora J.; Yuan, Bin; Zamora, Robert

    2014-10-01

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  16. High winter ozone pollution from carbonyl photolysis in an oil and gas basin.

    PubMed

    Edwards, Peter M; Brown, Steven S; Roberts, James M; Ahmadov, Ravan; Banta, Robert M; deGouw, Joost A; Dubé, William P; Field, Robert A; Flynn, James H; Gilman, Jessica B; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O; Lefer, Barry L; Lerner, Brian M; Li, Rui; Li, Shao-Meng; McKeen, Stuart A; Murphy, Shane M; Parrish, David D; Senff, Christoph J; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R; Trainer, Michael K; Tsai, Catalina; Veres, Patrick R; Washenfelder, Rebecca A; Warneke, Carsten; Wild, Robert J; Young, Cora J; Yuan, Bin; Zamora, Robert

    2014-10-16

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  17. High winter ozone pollution from carbonyl photolysis in an oil and gas basin.

    PubMed

    Edwards, Peter M; Brown, Steven S; Roberts, James M; Ahmadov, Ravan; Banta, Robert M; deGouw, Joost A; Dubé, William P; Field, Robert A; Flynn, James H; Gilman, Jessica B; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O; Lefer, Barry L; Lerner, Brian M; Li, Rui; Li, Shao-Meng; McKeen, Stuart A; Murphy, Shane M; Parrish, David D; Senff, Christoph J; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R; Trainer, Michael K; Tsai, Catalina; Veres, Patrick R; Washenfelder, Rebecca A; Warneke, Carsten; Wild, Robert J; Young, Cora J; Yuan, Bin; Zamora, Robert

    2014-10-16

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  18. A Negative Feedback Between Anthropogenic Ozone Pollution and Enhanced Ocean Emissions of Iodine

    NASA Astrophysics Data System (ADS)

    Saiz-Lopez, A.; Prados-Roman, C.; Cuevas, C.; Fernandez, R.; Lamarque, J. F.; Kinnison, D. E.

    2014-12-01

    Naturally emitted from the oceans, iodine compounds efficiently destroy atmospheric ozone and reduce its positive radiative forcing effects in the troposphere. Emissions of inorganic iodine have been experimentally shown to depend on the deposition to the oceans of tropospheric ozone, whose concentrations have significantly increased since 1850 as a result of human activities. A chemistry-climate model is used to quantify the current ocean emissions of inorganic iodine and assess the impact that the anthropogenic increase of tropospheric ozone has had on the natural cycle of iodine in the marine environment since pre-industrial times. Results included in this communication indicate that the human-driven enhancement of tropospheric ozone has doubled the oceanic inorganic iodine emissions following the reaction of ozone with iodide at the sea surface. The consequent build-up of atmospheric iodine, with maximum enhancements of up to 70% with respect to preindustrial times in continental pollution outflow regions, has in turn accelerated the ozone chemical loss over the oceans with strong spatial patterns. We suggest that this ocean-atmosphere interaction represents a negative geochemical feedback loop by which current ocean emissions of iodine act as a natural buffer for ozone pollution and its radiative forcing in the global marine environment.

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

    NASA Astrophysics Data System (ADS)

    Singer, Brett C.; Coleman, Beverly K.; Destaillats, Hugo; Hodgson, Alfred T.; Lunden, Melissa M.; Weschler, Charles J.; Nazaroff, William W.

    This study investigated the formation of secondary pollutants resulting from household product use in the presence of ozone. Experiments were conducted in a 50-m 3 chamber simulating a residential room. The chamber was operated at conditions relevant to US residences in polluted areas during warm-weather seasons: an air exchange rate of 1.0 h -1 and an inlet ozone concentration of approximately 120 ppb, when included. Three products were used in separate experiments. An orange oil-based degreaser and a pine oil-based general-purpose cleaner were used for surface cleaning applications. A plug-in scented-oil air freshener (AFR) was operated for several days. Cleaning products were applied realistically with quantities scaled to simulate residential use rates. Concentrations of organic gases and secondary organic aerosol from the terpene-containing consumer products were measured with and without ozone 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 was of similar magnitude to homogeneous reaction with continuously emitted constituents. Formaldehyde generation resulted from product use with ozone present, increasing indoor levels by the order of 10 ppb. Cleaning product use in the presence of ozone generated substantial fine particle concentrations (more than 100 μg 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.

  20. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection

    EPA Science Inventory

    Exposure to oxidant air pollution is associated with Increased respiratory morbiditses and susceptibility to Infections Ozone is a commonly encountered oxidant air pollutant, yet Its effects on influenza infections in humans are not known ‘the greater Mexico City area was the pri...

  1. Ozone and other air pollutants from photocopying machines

    SciTech Connect

    Hansen, T.B.; Andersen, B.

    1986-10-01

    The ozone emission from 69 different photocopying machines was determined by a described standard procedure. The emission rates were in the range of 0 to 1350 ..mu..g/min. The concentration in the breathing zone of 19 operators was found to be between less than or equal to 0.001 and 0.15 ppm. Technical conditions for the amount of ozone generated by photocopiers are described, as well as conditions for the rate of decomposition of ozone. The efficiencies of three different types of ozone filters were tested: activated carbon granulate; polyester; and polyurethane impregnated with activated carbon. Other pollutants levels from the copying process (selenium and cadmium) were less than the limit of detection. Dust concentrations (toner) in the air exhausted from photocopies were found in the same magnitude as normal dust concentrations in offices. Vapors from the resin in the toner were often present in concentrations and gave operators an unpleasant feeling.

  2. Process design for wastewater treatment: catalytic ozonation of organic pollutants.

    PubMed

    Derrouiche, S; Bourdin, D; Roche, P; Houssais, B; Machinal, C; Coste, M; Restivo, J; Orfão, J J M; Pereira, M F R; Marco, Y; Garcia-Bordeje, E

    2013-01-01

    Emerging micropollutants have been recently the target of interest for their potential harmful effects in the environment and their resistance to conventional water treatments. Catalytic ozonation is an advanced oxidation process consisting of the formation of highly reactive radicals from the decomposition of ozone promoted by a catalyst. Nanocarbon materials have been shown to be effective catalysts for this process, either in powder form or grown on the surface of a monolithic structure. In this work, carbon nanofibers grown on the surface of a cordierite honeycomb monolith are tested as catalyst for the ozonation of five selected micropollutants: atrazine (ATZ), bezafibrate, erythromycin, metolachlor, and nonylphenol. The process is tested both in laboratorial and real conditions. Later on, ATZ was selected as a target pollutant to further investigate the role of the catalytic material. It is shown that the inclusion of a catalyst improves the mineralization degree compared to single ozonation. PMID:24056437

  3. N-fixation in legumes--An assessment of the potential threat posed by ozone pollution.

    PubMed

    Hewitt, D K L; Mills, G; Hayes, F; Norris, D; Coyle, M; Wilkinson, S; Davies, W

    2016-01-01

    The growth, development and functioning of legumes are often significantly affected by exposure to tropospheric ozone (O3) pollution. However, surprisingly little is known about how leguminous Nitrogen (N) fixation responds to ozone, with a scarcity of studies addressing this question in detail. In the last decade, ozone impacts on N-fixation in soybean, cowpea, mung bean, peanut and clover have been shown for concentrations which are now commonly recorded in ambient air or are likely to occur in the near future. We provide a synthesis of the existing literature addressing this issue, and also explore the effects that may occur on an agroecosystem scale by predicting reductions in Trifolium (clovers) root nodule biomass in United Kingdom (UK) pasture based on ozone concentration data for a "high" (2006) and "average" ozone year (2008). Median 8% and 5% reductions in clover root nodule biomass in pasture across the UK were predicted for 2006 and 2008 respectively. Seasonal exposure to elevated ozone, or short-term acute concentrations >100 ppb, are sufficient to reduce N-fixation and/or impact nodulation, in a range of globally-important legumes. However, an increasing global burden of CO2, the use of artificial fertiliser, and reactive N-pollution may partially mitigate impacts of ozone on N-fixation. PMID:26385644

  4. N-fixation in legumes--An assessment of the potential threat posed by ozone pollution.

    PubMed

    Hewitt, D K L; Mills, G; Hayes, F; Norris, D; Coyle, M; Wilkinson, S; Davies, W

    2016-01-01

    The growth, development and functioning of legumes are often significantly affected by exposure to tropospheric ozone (O3) pollution. However, surprisingly little is known about how leguminous Nitrogen (N) fixation responds to ozone, with a scarcity of studies addressing this question in detail. In the last decade, ozone impacts on N-fixation in soybean, cowpea, mung bean, peanut and clover have been shown for concentrations which are now commonly recorded in ambient air or are likely to occur in the near future. We provide a synthesis of the existing literature addressing this issue, and also explore the effects that may occur on an agroecosystem scale by predicting reductions in Trifolium (clovers) root nodule biomass in United Kingdom (UK) pasture based on ozone concentration data for a "high" (2006) and "average" ozone year (2008). Median 8% and 5% reductions in clover root nodule biomass in pasture across the UK were predicted for 2006 and 2008 respectively. Seasonal exposure to elevated ozone, or short-term acute concentrations >100 ppb, are sufficient to reduce N-fixation and/or impact nodulation, in a range of globally-important legumes. However, an increasing global burden of CO2, the use of artificial fertiliser, and reactive N-pollution may partially mitigate impacts of ozone on N-fixation.

  5. A Climate Change Penalty in Pollution Ozone Observed over the Eastern US

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Bloomer, B. J.

    2008-12-01

    Numerical models predict that increasing temperatures due to greenhouse gas-induced climate change will increase ozone air pollution in some regions of the United States. We present evidence that an increase in ozone as a result of increasing temperatures is already observable in the Eastern US. We investigate 21 years of rural ozone observations (millions of hourly average values) spatially grouped into chemically coherent regions. We show that regional ozone amounts declined overall due to the decreasing power plant NOx emissions resulting from the Acid Rain Program and NOx SIP call. By constructing conditional ozone distributions for selected temperature bins we find a robust, nearly linear relationship for temperatures between 10 and 40°C. The slope was 3.2 ppb O3 per °C for 2002 and earlier, but fell to 2.2 ppb per °C after major emission reductions. For the period of 1987 to 2007 observed temperatures increased by 0.51 to 0.68°C, and the ozone temperature relationship indicates a climate change penalty for the mid-Atlantic region of between 1.1 and 2.2 ppb of ozone.

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

    NASA Astrophysics Data System (ADS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Calatayud, Vicent; Pierre Garrec, Jean; He, Shang; Peñuelas, Josep; Ribas, Àngela; Ro-Poulsen, Helge; Rasmussen, Stine; Sanz, María José; Vergne, Phillippe

    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, peak concentrations in the afternoon, and a decline during the night. The widest amplitudes between minimum and maximum values were found in central and southern European cities such as Düsseldorf, Verona, Klagenfurt, Lyon or Barcelona. In the northern European cities of Edinburgh and Copenhagen, 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, was observed. Only the Spanish cities did not fit this pattern; there, ozone levels were again lower than in central European cities, probably due to the direct influence of strong car traffic emissions. In general, ozone concentrations and cumulative exposure were significantly higher at suburban sites than at urban and traffic-exposed sites. When applying the newly established European Union (EU) Directive on ozone pollution in ambient air, it was demonstrated that the target value for the protection of human health was regularly surpassed at urban as well as suburban sites, particularly in cities in Austria, France, northern Italy and southern Germany. European target values and long-term objectives for the protection of vegetation expressed as AOT40 were also exceeded at many

  7. An Ozone Increase in the Antarctic Summer Stratosphere: A Dynamical Response to the Ozone Hole

    NASA Technical Reports Server (NTRS)

    Stolarski, R. S.; Douglass, A. R.; Gupta, M.; Newman, P. A.; Pawson, S.; Schoeberl, M. R.; Nielsen, J. E.

    2007-01-01

    Profiles of ozone concentration retrieved from the SBUV series of satellites show an increase between 1979 and 1997 in the summertime Antarctic middle stratosphere (approx. 25-10 hPa). Data over the South Pole from ozone sondes confirm the increase. A similar ozone increase is produced in a chemistry climate model that allows feedback between constituent changes and the stratospheric circulation through radiative heating. A simulation that excludes the radiative coupling between predicted ozone and the circulation does not capture this ozone increase. We show that the ozone increase in our model simulations is caused by a dynamical feedback in response to the changes in the stratospheric wind fields forced by the radiative perturbation associated with the Antarctic ozone hole.

  8. Plant injury by air pollutants: influence of humidity on stomatal apertures and plant response to ozone.

    PubMed

    Otto, H W; Daines, R H

    1969-03-14

    Ozone injury to Bel W3 tobacco and pinto bean plants increases with increasing humidity. The degree of plant injury sustained correlates well with porometer measurements; this indicates that the size of stomatal apertures increases with increasing humidity. Humidity may therefore influence plant response to all pollutants and may account in part for the greater sensitivity of plants to ozone-type injury in the eastern United States compared with the same species of plants grown in the Southwest. with those grown in the Southwest.

  9. Relationship between ozone and the air pollutants in Peninsular Malaysia for 2003 retrieved from SCIAMACHY

    NASA Astrophysics Data System (ADS)

    Tan, K. C.; Lim, H. S.; Mat Jafri, M. Z.

    2013-05-01

    Since few decades ago, air pollution has become a hot topic of environmental and atmospheric research due to the impact of air pollution on human health. Ozone is one of the important chemical constituent of the atmosphere, which plays a key role in atmospheric energy budget and chemistry, air quality and global change. Results from the analysis of the retrieved monthly data from Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY) were utilized, in order to analyze the impact of air pollutants (CO2, CH4, H2O, and NO2) on the ozone in Peninsular Malaysia for 2003 using multiple regression analysis. SCIAMACHY onboard ENVISAT as part of the atmospheric chemistry payload of the third European Space Agency (ESA) Earth observation, is the first satellite instrument whose measurements is enough precise and sensitive for all the greenhouse gases to make observation at all atmospheric altitude levels down to the Earth's surface. Among the four pollutants, ozone was most affected by water vapor (H2O vapor), indicated by a strong beta coefficient (-0.769 - 0.997), depends on the seasonal variety. In addition, CO2 also shows a strong Beta coefficient (-0.654 - 0.717) and also affected by the seasonal variation. The variation of pollutants on the average explains change 50.1% of the ozone. This means that about 50.1% of the ozone is attributed to these pollutant gases. The SCIAMACHY data and the satellite measurements successfully identify the increase of the atmospheric air pollutants over the study area.

  10. Impacts of ozonation on the competition between organic micro-pollutants and effluent organic matter in powdered activated carbon adsorption.

    PubMed

    Zietzschmann, F; Mitchell, R-L; Jekel, M

    2015-11-01

    This study investigates if ozonation of wastewater treatment plant (WWTP) effluent can reduce the negative impacts of effluent organic matter (EfOM) on the adsorption of organic micro-pollutants (OMP) onto powdered activated carbon (PAC). Pre-treatment of the water included membrane filtration for the removal of suspended/colloidal organics, ozonation with various specific ozone consumptions, and subsequent OMP spiking to comparable initial concentrations in all of the ozonated waters. This approach allowed for comparative PAC adsorption tests. Adsorption analyses show that the adsorbability of EfOM decreases with increasing specific ozone consumptions. This is also reflected by liquid chromatography with online carbon and UV254 detection (LC-OCD) which shows the ozone-induced disintegration of large EfOM into smaller fragments. Also, small organic neutrals are decreased while the small organic acids peak continuously increases with rising specific ozone consumptions. UV254 demonstrates that the aromaticity of all LC-OCD fractions continuously declines together with increasing specific O3 consumptions. This explains the varying EfOM adsorbabilities that occur due to ozonation. The ozone-induced decrease of EfOM adsorbability directly translates into reduced adsorption competition against the adsorption of OMP. With higher specific ozone consumptions, OMP removal and OMP loadings increase. The reduced adsorption competition is reflected in the outputs from equivalent background compound (EBC) modeling. In each of the ozonated waters, correlations between the OMP removals and the UV254 removal were found.

  11. Impacts of ozonation on the competition between organic micro-pollutants and effluent organic matter in powdered activated carbon adsorption.

    PubMed

    Zietzschmann, F; Mitchell, R-L; Jekel, M

    2015-11-01

    This study investigates if ozonation of wastewater treatment plant (WWTP) effluent can reduce the negative impacts of effluent organic matter (EfOM) on the adsorption of organic micro-pollutants (OMP) onto powdered activated carbon (PAC). Pre-treatment of the water included membrane filtration for the removal of suspended/colloidal organics, ozonation with various specific ozone consumptions, and subsequent OMP spiking to comparable initial concentrations in all of the ozonated waters. This approach allowed for comparative PAC adsorption tests. Adsorption analyses show that the adsorbability of EfOM decreases with increasing specific ozone consumptions. This is also reflected by liquid chromatography with online carbon and UV254 detection (LC-OCD) which shows the ozone-induced disintegration of large EfOM into smaller fragments. Also, small organic neutrals are decreased while the small organic acids peak continuously increases with rising specific ozone consumptions. UV254 demonstrates that the aromaticity of all LC-OCD fractions continuously declines together with increasing specific O3 consumptions. This explains the varying EfOM adsorbabilities that occur due to ozonation. The ozone-induced decrease of EfOM adsorbability directly translates into reduced adsorption competition against the adsorption of OMP. With higher specific ozone consumptions, OMP removal and OMP loadings increase. The reduced adsorption competition is reflected in the outputs from equivalent background compound (EBC) modeling. In each of the ozonated waters, correlations between the OMP removals and the UV254 removal were found. PMID:26231581

  12. Convection links biomass burning to increased tropical ozone - However, models will tend to overpredict O3

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert B.; Delany, Anthony C.

    1990-01-01

    Biomass burning throughout the inhabited portions of the tropics generates precursors which lead to significant local atmospheric ozone pollution. Several simulations show how this smog could be only an easily observed, local manifestation of a much broader increase in tropospheric ozone. The basic processes are illustrated with a one-dimensional time-dependent model that is closer to true meteorological motions than commonly used eddy diffusion models. Its application to a representative region of South America gives reasonable simulations of the local pollutants measured there. Three illustrative simulations indicate the importance of dilution, principally due to vertical transport, in increasing the efficiency of ozone production, possibly enough for high ozone to be apparent on a very large, intercontinental scale.

  13. Tropospheric Ozone Pollution Transport Traced from the TOMS (Total Ozone Mapping Spectrometer) Instrument During the Nashville-1999 Campaign

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Frolov, A. D.; Hudson, R. D.; Witte, J. C.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Over the past several years, we have developed two new tropospheric ozone retrievals from the TOMS (Total Ozone Mapping Spectrometer) satellite instrument that are of sufficient resolution to follow pollution episodes. 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 TOMS-direct method [("TDOT" = TOMS Direct Ozone in the Troposphere; Frolov et al., 2000] represents a new algorithm that uses TOMS radiances directly (i.e., not previously processed for TOMS ozone) to extract tropospheric ozone in regions of constant stratospheric ozone and tropospheric ozone displaying high mixing ratios and variability characteristic of pollution. These events tend to occur in certain meteorological regimes. For example, mid-latitude pollution usually occurs on the backside of subtropical fronts, as low pv, usually moist air intrudes to the extra-tropics. July 1999 was a month characterized by robust pollution in the eastern US, with high ozone, as detected by TOMS, originating over south central states and moving up the Atlantic seaboard. This corresponds to 50-80 DU in tropospheric ozone column depth. In most cases, further transport occurred to the North Atlantic, with ozone plumes traveling to western Europe in 4-5 days. Examples of high ozone and transit across boundaries within the US, as well as US->Europe, give a regional context for model results and field measurements taken in the SE US during the Nashville-1999 campaign period. Validation of the TDOT maps is made with ozonesondes taken during that time. TDOT maps also show ozone pollution from Asia traveling to the western US in July 1999.

  14. Significant increase of surface ozone at a rural site, north of eastern China

    NASA Astrophysics Data System (ADS)

    Ma, Zhiqiang; Xu, Jing; Quan, Weijun; Zhang, Ziyin; Lin, Weili; Xu, Xiaobin

    2016-03-01

    Ozone pollution in eastern China has become one of the top environmental issues. Quantifying the temporal trend of surface ozone helps to assess the impacts of the anthropogenic precursor reductions and the likely effects of emission control strategies implemented. In this paper, ozone data collected at the Shangdianzi (SDZ) regional atmospheric background station from 2003 to 2015 are presented and analyzed to obtain the variation in the trend of surface ozone in the most polluted region of China, north of eastern China or the North China Plain. A modified Kolmogorov-Zurbenko (KZ) filter method was performed on the maximum daily average 8 h (MDA8) concentrations of ozone to separate the contributions of different factors from the variation of surface ozone and remove the influence of meteorological fluctuations on surface ozone. Results reveal that the short-term, seasonal and long-term components of ozone account for 36.4, 57.6 and 2.2 % of the total variance, respectively. The long-term trend indicates that the MDA8 has undergone a significant increase in the period of 2003-2015, with an average rate of 1.13 ± 0.01 ppb year-1 (R2 = 0.92). It is found that meteorological factors did not significantly influence the long-term variation of ozone and the increase may be completely attributed to changes in emissions. Furthermore, there is no significant correlation between the long-term O3 and NO2 trends. This study suggests that emission changes in VOCs might have played a more important role in the observed increase of surface ozone at SDZ.

  15. Ozone-induced increase in bean leaf maintenance respiration

    SciTech Connect

    Amthor, J.S.

    1987-01-01

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

  16. A study of aerosol optical properties during ozone pollution episodes in 2013 over Shanghai, China

    NASA Astrophysics Data System (ADS)

    Shi, Chanzhen; Wang, Shanshan; Liu, Rui; Zhou, Rui; Li, Donghui; Wang, Wenxin; Li, Zhengqiang; Cheng, Tiantao; Zhou, Bin

    2015-02-01

    Aerosol optical property is essential to the tropospheric ozone formation mechanism while it was rarely measured in ozone-rich environment for a specific study. With the retrieved products of the sun-photometer, a comparative investigation was conducted on aerosol optical depth (AOD), single scattering albedo (SSA) and size distribution during ozone-polluted episodes and clean background. Contrary to expectations, aerosol loading was found to be positively-correlated with ozone concentration: daily averaged AOD at 500 nm in ozone episodes (~ 0.78) displayed 2.4 times higher than that in clean days (~ 0.32). Large Ångström exponent (~ 1.51) along with heavy aerosol loading indicated a considerable impact of fine particles on optical extinction. The dynamic diurnal fluctuation of these parameters also implied a complex interaction between aerosols and photo-chemical reactions. The bimodal lognormal distribution pattern for aerosol size spectra exhibited in both ozone-polluted and clean days. The occurrence of maximum volume concentration (~ 0.28) in fine mode (radius < 0.6 μm) was observed at 3 p.m. (local time), when ozone was substantially generated. Pronounced scattering feature of aerosol was reproduced in high-concentration ozone environment. SSA tended to increase continuously from morning (~ 0.91 at 440 nm) to afternoon (~ 0.99), which may be associated with secondary aerosol formation. The scattering aerosol (with moderately high aerosol loading) may favor the ozone formation through increasing solar flux in boundary layer. Utilizing the micro-pulse lidar (MPL), a more developed planet boundary layer (PBL, top height ~ 1.96 km) was discovered during ozone-polluted days than clean condition (~ 1.4 km). In episodes, the maximum extinction ratio (~ 0.5 km- 1) was presented at a height of 1.2 km in the late afternoon. The humidity profile by sounding also showed the extreme value at this altitude. It suggested that optical extinction was mainly attributed to

  17. The Impact of Increasing Carbon Dioxide on Ozone Recovery

    NASA Technical Reports Server (NTRS)

    Rosenfield, Joan E.; Douglass, Anne R.; Considine, David B.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    We have used the GSFC coupled two-dimensional (2D) model to study the impact of increasing carbon dioxide from 1980 to 2050 on the recovery of ozone to its pre-1980 amounts. We find that the changes in temperature and circulation arising from increasing CO2 affect ozone recovery in a manner which varies greatly with latitude, altitude, and time of year. Middle and upper stratospheric ozone recovers faster at all latitudes due to a slowing of the ozone catalytic loss cycles. In the lower stratosphere, the recovery of tropical ozone is delayed due to a decrease in production and a speed up in the overturning circulation. The recovery of high northern latitude lower stratospheric ozone is delayed in spring and summer due to an increase in springtime heterogeneous chemical loss, and is speeded up in fall and winter due to increased downwelling. The net effect on the higher northern latitude column ozone is to slow down the recovery from late March to late July, while making it faster at other times. In the high southern latitudes, the impact of CO2 cooling is negligible. Annual mean column ozone is predicted to recover faster at all latitudes, and globally averaged ozone is predicted to recover approximately ten years faster as a result of increasing CO2.

  18. The negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine

    NASA Astrophysics Data System (ADS)

    Cuevas, Carlos A.; Prados-Roman, Cristina; Fernandez, Rafael P.; Kinnison, Douglas E.; Lamarque, Jean-Francois; Saiz-Lopez, Alfonso

    2015-04-01

    Natural emissions of iodine compounds from the oceans efficiently destroy atmospheric ozone reducing its positive radiative forcing effects in the troposphere. Emissions of inorganic iodine have been experimentally shown to depend on the deposition to the oceans of tropospheric ozone, whose concentrations have significantly increased (40%) since 1850 as a result of human activities. In this work a chemistry-climate model is used to quantify the current ocean emissions of inorganic iodine and evaluate the impact that the anthropogenic increase of tropospheric ozone has had on the natural cycle of iodine in the marine environment since pre-industrial times. Our results indicate that the human driven enhancement of tropospheric ozone has doubled the oceanic inorganic iodine emissions following the reaction of ozone with iodide at the sea surface. The consequent build-up of atmospheric iodine, with maximum enhancements of up to 70% with respect to preindustrial times in continental pollution outflow regions, has in turn accelerated the ozone chemical loss over the oceans with strong spatial patterns. We suggest that this ocean-atmosphere interaction represents a negative geochemical feedback loop by which current ocean emissions of iodine act as a natural buffer for ozone pollution and its radiative forcing in the global marine environment. This feedback represents a potentially important link between climate change and tropospheric O3 since the oceanic emissions of iodine are not only linked to surface O3, but also to SST and wind speed and might also be linked to climatically driven changes in the state of the world oceans.

  19. The global consequences of increasing tropospheric ozone concentrations

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1989-01-01

    Recent analyses of long term records of tropospheric ozone measurements in the Northern Hemisphere suggest that it is increasing at a rate of 1 to 2 percent per year. Because of this, it is argued that the amount of atmospheric warming due to increasing tropospheric ozone is comparable to, or possibly even greater than, the amount of warming due to the increase of carbon dioxide. Unlike all other climatically important trace gases, ozone is toxic, and increases in its concentration will result in serious environmental damage, as well as impairment of human health.

  20. Ozone and photochemical pollutants: status after 25 years

    SciTech Connect

    Speizer, F.E.

    1985-03-01

    Data related to the health effects of air pollution are discussed in this editorial. Three kinds of studies - animal experimentation, controlled chamber experiments in both animals and humans and population-based epidemiological investigations are reported from a seminar held at the University of California, Davis. Each is summarized as to whether it proved to be a health effect for ozone or NO/sub 2/. The role of physicians in the interpretation of the data and in public policy decision-making is examined.

  1. Haze and ozone pollution effects on the land carbon sink in China

    NASA Astrophysics Data System (ADS)

    Yue, X.; Unger, N.; Harper, K.

    2015-12-01

    Atmospheric pollutants have both beneficial and detrimental effects on carbon assimilation by land ecosystems. Aerosols promote carbon uptake by increasing diffuse radiation, while ozone damages leaf photosynthesis by oxidizing plant cells. As the world's largest emitter of air pollutants, China experiences frequent haze episodes. In this study, we apply coupled chemistry-carbon-climate simulations using the Yale Interactive Terrestrial Biosphere Model that is embedded in the NASA ModelE2 global chemistry-climate model to quantify the combined effects of ozone and aerosol pollution on land carbon assimilation for the present and future world. The simulated land carbon cycle has been extensively evaluated at 145 FLUXNET sites globally. The aerosol optical depth (AOD) and surface ozone are validated with satellite data and air quality monitoring data from a network of 188 Chinese sites. In the present day, we find that air pollution in China reduces net primary productivity (NPP) by 0.47 Pg C a-1 (10.8%), resulting from an increase of 0.13 Pg C a-1 (3.1%) by aerosol diffuse radiation fertilization and a decrease of 0.60 Pg C a-1 (13.9%) by ozone vegetation damage. Sensitivity simulations indicate that the effects are dominated by anthropogenic emissions. Simulations using natural precursor emissions only show minor changes in NPP. The IPCC RCP8.5 future world predicts an 18% reduction in SO2 emissions but increases of 17% in NOx and 15% in volatile organic compound emissions in 2030 relative to 2010. The emissions changes lead to reduced AOD but enhanced surface ozone over eastern China in 2030. For this future projection, we estimate a stronger NPP reduction of 0.62 Pg C a-1 (12.5%) due to air pollution in 2030. The increased future damage is a consequence of the opposing sign effects of aerosol diffuse radiation fertilization (0.13 Pg C a-1; 2.6%) and larger ozone inhibition (0.75 Pg C a-1; 15.1%).

  2. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    PubMed

    Kesic, Matthew J; Meyer, Megan; Bauer, Rebecca; Jaspers, Ilona

    2012-01-01

    Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility. PMID

  3. Exposure to Ozone Modulates Human Airway Protease/Antiprotease Balance Contributing to Increased Influenza A Infection

    PubMed Central

    Kesic, Matthew J.; Meyer, Megan; Bauer, Rebecca; Jaspers, Ilona

    2012-01-01

    Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility. PMID

  4. Ozone inhalation leads to a dose-dependent increase of cytogenetic damage in human lymphocytes.

    PubMed

    Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

    2015-05-01

    Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we used a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than one MN per cell (P <  .0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments.

  5. Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

    PubMed Central

    Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

    2014-01-01

    Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

  6. Geospatial Interpolation and Mapping of Tropospheric Ozone Pollution Using Geostatistics

    PubMed Central

    Kethireddy, Swatantra R.; Tchounwou, Paul B.; Ahmad, Hafiz A.; Yerramilli, Anjaneyulu; Young, John H.

    2014-01-01

    Tropospheric ozone (O3) pollution is a major problem worldwide, including in the United States of America (USA), particularly during the summer months. Ozone oxidative capacity and its impact on human health have attracted the attention of the scientific community. In the USA, sparse spatial observations for O3 may not provide a reliable source of data over a geo-environmental region. Geostatistical Analyst in ArcGIS has the capability to interpolate values in unmonitored geo-spaces of interest. In this study of eastern Texas O3 pollution, hourly episodes for spring and summer 2012 were selectively identified. To visualize the O3 distribution, geostatistical techniques were employed in ArcMap. Using ordinary Kriging, geostatistical layers of O3 for all the studied hours were predicted and mapped at a spatial resolution of 1 kilometer. A decent level of prediction accuracy was achieved and was confirmed from cross-validation results. The mean prediction error was close to 0, the root mean-standardized-prediction error was close to 1, and the root mean square and average standard errors were small. O3 pollution map data can be further used in analysis and modeling studies. Kriging results and O3 decadal trends indicate that the populace in Houston-Sugar Land-Baytown, Dallas-Fort Worth-Arlington, Beaumont-Port Arthur, San Antonio, and Longview are repeatedly exposed to high levels of O3-related pollution, and are prone to the corresponding respiratory and cardiovascular health effects. Optimization of the monitoring network proves to be an added advantage for the accurate prediction of exposure levels. PMID:24434594

  7. Air pollutants degrade floral scents and increase insect foraging times

    NASA Astrophysics Data System (ADS)

    Fuentes, Jose D.; Chamecki, Marcelo; Roulston, T.'ai; Chen, Bicheng; Pratt, Kenneth R.

    2016-09-01

    Flowers emit mixtures of scents that mediate plant-insect interactions such as attracting insect pollinators. Because of their volatile nature, however, floral scents readily react with ozone, nitrate radical, and hydroxyl radical. The result of such reactions is the degradation and the chemical modification of scent plumes downwind of floral sources. Large Eddy Simulations (LES) are developed to investigate dispersion and chemical degradation and modification of floral scents due to reactions with ozone, hydroxyl radical, and nitrate radical within the atmospheric surface layer. Impacts on foraging insects are investigated by utilizing a random walk model to simulate insect search behavior. Results indicate that even moderate air pollutant levels (e.g., ozone mixing ratios greater than 60 parts per billion on a per volume basis, ppbv) substantially degrade floral volatiles and alter the chemical composition of released floral scents. As a result, insect success rates of locating plumes of floral scents were reduced and foraging times increased in polluted air masses due to considerable degradation and changes in the composition of floral scents. Results also indicate that plant-pollinator interactions could be sensitive to changes in floral scent composition, especially if insects are unable to adapt to the modified scentscape. The increase in foraging time could have severe cascading and pernicious impacts on the fitness of foraging insects by reducing the time devoted to other necessary tasks.

  8. Ozone solubilizes elastin and increases its susceptibility to elastase

    SciTech Connect

    Winters, R.S.; Johnson, D.A. )

    1991-03-11

    Ozone is a powerful oxidant gas that may contribute to lung diseases such as emphysema. Because the hallmark of emphysema is destruction of the elastin rich alveoli of the lung, ozonization of elastin was studied in vitro to examine the effects of ozone on elastin structure and susceptibility to proteolysis. Samples of bovine ligamentum nuchae elastin were suspended in 15 ml PBS and bubbled with 13.7 ppm ozone in argon at a flow rate of 3.5 ml/min. Ozone treatment resulted in the solubilization of elastin as evidenced by a visual decrease in turbidity and an increase in the 225 nm absorbance of the supernatant fraction after centrifugation to pellet the insoluble elastin. Insoluble elastin recovered from exposed suspensions was examined for proteolytic susceptibility with human neutrophil elastase (HNE), by incubating 600 {mu}g samples in 1 ml of 50 mM Tris-HCl, 200 mM NaCl, pH 8.0 with 3 {mu}g HNE for various times at room temp. Elastin proteolysis was followed by measuring the 225 nm absorbance of solubilized peptides in supernatant fractions. Ozone exposed elastin, which had been previously ozonized to 5% solubility was found to be approximately twice as susceptible to proteolysis as native elastin.

  9. Impact of ozonation in removing organic micro-pollutants in primary and secondary municipal wastewater: effect of process parameters.

    PubMed

    Mecha, Achisa C; Onyango, Maurice S; Ochieng, Aoyi; Momba, Maggy N B

    2016-01-01

    The study investigates the influence of process parameters on the effectiveness of ozonation in the removal of organic micro-pollutants from wastewater. Primary and secondary municipal wastewater containing phenol was treated. The effect of operating parameters such as initial pH, ozone dosage, and initial contaminant concentration was studied. An increase in contaminant decomposition with pH (3-11) was observed. The contaminant removal efficiencies increased with an increase in ozone dose rate (5.5-36.17 mg L(-1) min(-1)). Furthermore, the ultraviolet absorbance (UV 254 nm) of the wastewater decreased during ozonation indicating the breakdown of complex organic compounds into low molecular weight organics. Along the reaction, the pH of wastewater decreased from 11 to around 8.5 due to the formation of intermediate acidic species. Moreover, the biodegradability of wastewaters, measured as biological and chemical oxygen demand (BOD5/COD), increased from 0.22 to 0.53. High ozone utilization efficiencies of up to 95% were attained thereby increasing the process efficiency; and they were dependent on the ozone dosage and pH of solution. Ozonation of secondary wastewater attained the South African water standards in terms of COD required for wastewater discharge and dissolved organic carbon in drinking water and increased significantly the biodegradability of primary wastewater. PMID:27508381

  10. The characterization of an air pollution episode using satellite total ozone measurements

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Shipham, Mark C.; Vukovich, Fred M.; Cahoon, Donald R.

    1987-01-01

    A case study is presented which demonstrates that measurements of total ozone from a space-based platform can be used to study a widespread air pollution episode over the southeastern U.S. In particular, the synoptic-scale distribution of surface-level ozone obtained from an independent analysis of ground-based monitoring stations appears to be captured by the synoptic-scale distribution of total ozone, even though about 90 percent of the total ozone is in the stratosphere. Additional analyses of upper air meteorological data, other satellite imagery, and in situ aircraft measurements of ozone likewise support the fact that synoptic-scale variability of tropospheric ozone is primarily responsible for the observed variability in total ozone under certain conditions. The use of the type of analysis discussed in this study may provide an important technique for understanding the global budget of tropospheric ozone.

  11. Nutritional traits of bean ( Phaseolus vulgaris ) seeds from plants chronically exposed to ozone pollution.

    PubMed

    Iriti, Marcello; Di Maro, Antimo; Bernasconi, Silvana; Burlini, Nedda; Simonetti, Paolo; Picchi, Valentina; Panigada, Cinzia; Gerosa, Giacomo; Parente, Augusto; Faoro, Franco

    2009-01-14

    The effect of chronic exposure to ozone pollution on nutritional traits of bean ( Phaseolus vulgaris L. cv. Borlotto Nano Lingua di Fuoco) seeds from plants grown in filtered and nonfiltered open-top chambers (OTCs) has been investigated. Results showed that, among seed macronutrients, ozone significantly raised total lipids, crude proteins, and dietary fiber and slightly decreased total free amino acid content, although with a significant reduction of asparagine, lysine, valine, methionine, and glycine, compensated by a conspicuous augmentation of ornithine and tryptophan. Phytosterol analysis showed a marked increase of beta-sitosterol, stigmasterol, and campesterol in seeds collected from nonfiltered OTCs. With regard to secondary metabolites, ozone exposure induced a slight increase of total polyphenol content, although causing a significant reduction of some flavonols (aglycone kaempferol and its 3-glucoside derivative) and hydroxycinnamates (caffeic, p-coumaric, and sinapic acids). Total anthocyanins decreased significantly, too. Nevertheless, ozone-exposed seeds showed higher antioxidant activity, with higher Trolox equivalent antioxidant capacity (TEAC) values than those measured in seeds collected from filtered air.

  12. Ozone depletion, related UVB changes and increased skin cancer incidence

    NASA Astrophysics Data System (ADS)

    Kane, R. P.

    1998-03-01

    Stratospheric ozone at middle latitudes shows a seasonal variation of about +/-20%, a quasi-biennial oscillation of 1-10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10-20%, which should cause an increase in skin cancer incidence of about 20-40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974-1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and

  13. Increasing surface ozone concentrations in the background atmosphere of Southern China, 1994-2007

    NASA Astrophysics Data System (ADS)

    Wang, T.; Wei, X. L.; Ding, A. J.; Poon, C. N.; Lam, K. S.; Li, Y. S.; Chan, L. Y.; Anson, M.

    2009-08-01

    Tropospheric ozone is of great importance with regard to air quality, atmospheric chemistry, and climate change. In this paper we report the first continuous record of surface ozone in the background atmosphere of South China. The data were obtained from 1994 to 2007 at a coastal site in Hong Kong, which is strongly influenced by the outflow of Asian continental air during the winter and the inflow of maritime air from the subtropics in the summer. Three methods are used to derive the rate of change in ozone. A linear fit to the 14-year record shows that the ozone concentration increased by 0.58 ppbv/yr, whereas comparing means in years 1994-2000 and 2001-2007 gives an increase of 0.87 ppbv/yr for a 7-year period. The ozone changes in air masses from various source regions are also examined. Using local wind and carbon monoxide (CO) data to filter out local influence, we find that ozone increased by 0.94 ppbv/yr from 1994-2000 to 2001-2007 in air masses from Eastern China, with similar changes in the other two continent-influenced air-mass groups, but no statistically significant change in the marine air. An examination of the nitrogen dioxide (NO2) column obtained from GOME and SCIAMACHY reveals an increase in atmospheric NO2 in China's three fastest developing coastal regions, whereas NO2 in other parts of Asia decreased during the same period, and no obvious trend over the main shipping routes in the South China Sea was indicated. Thus the observed increase in background ozone in Hong Kong is most likely due to the increased emissions of NO2 (and possibly volatile organic compounds (VOCs) as well) in the upwind coastal regions of mainland China. The CO data at Hok Tsui showed less definitive changes compared to the satellite NO2 column. The increase in background ozone likely made a strong contribution (81%) to the rate of increase in "total ozone" at an urban site in Hong Kong, suggesting the need to consider distant sources when developing long-term strategies

  14. Significance of pollutant concentration distribution in the response of 'Red Kidney' beans to ozone

    SciTech Connect

    Musselman, R.C.; Oshima, R.J.; Gallavan, R.E.

    1983-01-01

    Bean plants (Phaseolus vulgaris L. cv. red kidney) exposed to ozone with a simulated ambient concentration distribution showed significantly more injury, less growth, and lower yield than those exposed to an equivalent dose of ozone with a uniform concentration distribution. The concentration distribution did not alter the type of biological response of red kidney beans to ozone, an indication that uniform concentration distribution fumigations are appropriate for investigations of mode of action of pollutants on plants. However, this study suggests that research using a uniform concentration distribution of pollutants may underestimate the magnitude of growth and yield responses to ambient pollutants. 26 references, 1 figure, 3 tables.

  15. Maternal Diesel Inhalation Increases Airway Hyperreactivity in Ozone Exposed Offspring

    EPA Science Inventory

    Air pollutant exposure is linked with childhood asthma incidence and exacerbations, and maternal exposure to airborne pollutants during pregnancy increases airway hyperreactivity (ARR) in offspring. To determine if exposure to diesel exhaust during pregnancy worsened postnatal oz...

  16. Ozone Pollution, Transport and Variability: Examples from Satellite and In-Situ Observations

    NASA Technical Reports Server (NTRS)

    Thompson, Anne

    2003-01-01

    Regional and intercontinental transport of ozone has been observed from satellite, aircraft and sounding data. Over the past several years, we have developed new tropospheric ozone retrieval techniques from the TOMS (Total Ozone Mapping Spectrometer) satellite instrument that are of sufficient resolution to follow pollution episodes. The modified-residual technique uses Level 2 total ozone and was used to follow the 1997 fires in the wake of the El-Nino-related fires in southeast Asia and the Indonesian maritime continent. The TOMS-direct method ('TDOT' = TOMS Direct Ozone in the Troposphere) is a newer algorithm that uses TOMS radiances directly to extract tropospheric ozone. Ozonesonde data that have been taken in campaigns (e.g. TRACE-P) and more consistently in the SHADOZ (Southern Hemisphere Additional Ozonesondes) project, reveal layers of pollution traceable with trajectories. Examples will be shown of long-range transport and recirculation over Africa during SAFARI-2000.

  17. Are recent Arctic ozone losses caused by increasing greenhouse gases?

    NASA Astrophysics Data System (ADS)

    Rieder, Harald E.; Polvani, Lorenzo M.

    2013-08-01

    has been suggested that the Arctic ozone losses observed in recent years might be a manifestation of climate change due to increasing greenhouse gases. We here offer evidence to the contrary, by focusing on the volume of polar stratospheric clouds (VPSC), a convenient proxy for polar ozone loss whose simplicity allows for easily reproducible results. First, we analyze the time series of VPSC in three reanalysis data sets and find no statistically significant trends in VPSC-nor changes in their probability density functions-over the period 1979-2011. Second, we analyze VPSC in a stratosphere-resolving chemistry-climate model forced uniquely with increasing greenhouse gases following the A1B scenario: here too, we find no significant changes in VPSC over the entire 21st century. Taken together, these results strongly suggest that the sporadic high ozone losses in recent years have not been caused by increasing greenhouse gases.

  18. Are recent Arctic ozone losses caused by increasing greenhouse gases?

    NASA Astrophysics Data System (ADS)

    Rieder, H.; Polvani, L. M.

    2013-12-01

    It has been suggested that the Arctic ozone losses observed in recent years might be a manifestation of climate change due to increasing greenhouse gases. We here offer evidence to the contrary, by focusing on the volume of polar stratospheric clouds (VPSC), a convenient proxy for polar ozone loss whose simplicity allows for easily reproducible results. First, we analyze the time series of VPSC in three reanalysis datasets and find no statistically significant trends in VPSC - nor changes in their probability density functions - over the period 1979-2011. Second, we analyze VPSC in a stratosphere-resolving chemistry-climate model forced uniquely with increasing greenhouse gases following the A1B scenario: here too, we find no significant changes in VPSC over the entire 21st century. Taken together, these results strongly suggest that the sporadic high ozone losses in recent years have not been caused by increasing greenhouse gases.

  19. Evidence for an increase in the ozone photochemical lifetime in the eastern United States using a regional air quality model

    NASA Astrophysics Data System (ADS)

    Goldberg, Daniel L.; Vinciguerra, Timothy P.; Hosley, Kyle M.; Loughner, Christopher P.; Canty, Timothy P.; Salawitch, Ross J.; Dickerson, Russell R.

    2015-12-01

    Measures to control surface ozone rely on quantifying production attributable to local versus regional (upwind) emissions. Here we simulate the relative contribution of local (i.e., within a particular state) and regional sources of surface ozone in the eastern United States (66-94°W longitude) for July 2002, 2011, and 2018 using the Comprehensive Air-quality Model with Extensions (CAMx). To determine how emissions and chemistry within the domain affect the production, loss, lifetime, and transport of trace gases, we initialize our model with identical boundary conditions in each simulation. We find that the photochemical lifetime of ozone has increased as emissions have decreased. The contribution of ozone from outside the domain (boundary condition ozone, BCO3) to local surface mixing ratios increases in an absolute sense by 1-2 ppbv between 2002 and 2018 due to the longer lifetime of ozone. The photochemical lifetime of ozone lengthens because the two primary gas phase sinks for odd oxygen (Ox ≈ NO2 + O3)—attack by hydroperoxyl radicals (HO2) on ozone and formation of nitrate—weaken with decreasing pollutant emissions. The relative role of BCO3 will also increase. For example, BCO3 represents 34.5%, 38.8%, and 43.6% of surface ozone in the Baltimore, MD, region during July 2002, 2011, and 2018 means, respectively. This unintended consequence of air quality regulation impacts attainment of the National Ambient Air Quality Standard for surface ozone because the spatial and temporal scales of photochemical smog increase; the influence of pollutants transported between states and into the eastern U.S. will likely play a greater role in the future.

  20. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    SciTech Connect

    Chan, Wai Kit; Joueet, Justine; Heng, Samuel; Yeung, King Lun; Schrotter, Jean-Christophe

    2012-05-15

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: Black-Right-Pointing-Pointer Novel reactor using membranes for ozone distributor, reaction contactor and water separator. Black-Right-Pointing-Pointer Designed to achieve an order of magnitude enhancement over traditional reactor. Black-Right-Pointing-Pointer Al{sub 2}O{sub 3} and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. Black-Right-Pointing-Pointer High surface area coating prevents polarization and improves membrane separation and life.

  1. Brown Cloud Pollution and Smog Ozone Transport 6,000 km to the Tropical Atlantic: Mechanism and Sensing

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert B.; Thompson, Anne M.; Guan, Hong; Witte, Jacquelyn C.; Hudson, Robert D.

    2004-01-01

    We have found repeated illustrations in the maps of Total Tropospheric Ozone (TTO) of apparent transport of ozone from the Indian Ocean to the Equatorial Atlantic Ocean. Most interesting are examples that coincide with the INDOEX observations of late northern winter. Three soundings with the SHADOZ (Southern Hemisphere Additional Ozonesondes) network help confirm and quantify degree of influence of pollution, lightning, and stratospheric sources, suggesting that perhaps 40% of increased Atlantic ozone could be Asian pollution during periods of maximum identified in the TTO maps. This analysis also indicates a mechanism for such extended transport. We outline recurrent periods of apparent ozone transport from Indian to Atlantic Ocean regions outside the late-winter period. Clearly brown-cloud aerosol affects tropospheric ozone, both limiting its chemical production and also potentially obscuring its detection by the TOMS instrument. Introductory statistical studies will be presented, evaluating the role of tropopause meteorology, aerosol, and other factors in the modifying the relationship between true tropospheric ozone measured by SHADOZ and the TTO product, with suggestions for extending the product.

  2. Ozone exposure increases respiratory epithelial permeability in humans

    SciTech Connect

    Kehrl, H.R.; Vincent, L.M.; Kowalsky, R.J.; Horstman, D.H.; O'Neil, J.J.; McCartney, W.H.; Bromberg, P.A.

    1987-05-01

    Ozone is a respiratory irritant that has been shown to cause an increase in the permeability of the respiratory epithelium in animals. We used inhaled aerosolized /sup 99m/Tc-labeled diethylene triamine pentacetic acid (/sup 99m/Tc-DTPA) to investigate whether human respiratory epithelial permeability is similarly affected by exposure to ozone. In a randomized, crossover double-blinded study, 8 healthy, nonsmoking young men were exposed for 2 h to purified air and 0.4 ppm ozone while performing intermittent high intensity treadmill exercise (minute ventilation = 66.8 L/min). SRaw and FVC were measured before and at the end of exposures. Seventy-five minutes after the exposures, the pulmonary clearance of /sup 99m/Tc-DTPA was measured by sequential posterior lung imaging with a computer-assisted gamma camera. Ozone exposure caused respiratory symptoms in all 8 subjects and was associated with a 14 +/- 2.8% (mean +/- SEM) decrement in FVC (p less than 0.001) and a 71 +/- 22% increase in SRaw (p = 0.04). Compared with the air exposure day, 7 of the 8 subjects showed increased /sup 99m/Tc-DTPA clearance after the ozone exposure, with the mean value increasing from 0.59 +/- 0.08 to 1.75 +/- 0.43%/min (p = 0.03). These data show that ozone exposure sufficient to produce decrements in the pulmonary function of human subjects also causes an increase in /sup 99m/Tc-DTPA clearance.

  3. Increasing surface ozone concentrations in the background atmosphere of southern China, 1994-2007

    NASA Astrophysics Data System (ADS)

    Wang, T.; Wei, X. L.; Ding, A. J.; Poon, C. N.; Lam, K. S.; Li, Y. S.; Chan, L. Y.; Anson, M.

    2009-04-01

    Tropospheric ozone is of great importance with regard to air quality, atmospheric chemistry, and climate change. In this paper we report the first continuous record of surface ozone in the background atmosphere of South China. The data were obtained from 1994 to 2007 at a coastal site in Hong Kong, which is strongly influenced by the outflow of Asian continental air during the winter and the inflow of maritime air from the subtropics in the summer. Overall, the ozone concentration increased by an averaged rate of 0.55 ppbv/yr, with a larger increase in autumn (0.68 ppbv/yr). We also examine the trend in air masses from various source regions in Asia. Using local wind and concurrently measured carbon monoxide (CO) data to filter out local emissions, the mean ozone in air masses from eastern China, using the pooled averaging method, increased by 0.64 ppbv/yr, while ozone levels in other air-mass groups showed a positive trend (0.29-0.67 ppbv/yr) but with lower levels of statistical significance. An examination of the nitrogen dioxide (NO2) column concentration data obtained from GOME and SCIAMACHY reveals an increase in atmospheric NO2 in the three fastest developing coastal regions of China, whereas NO2 in other parts of Asia decreased during the same period. It is believed that the observed increase in background ozone in Hong Kong is primarily due to the increased emissions of NO2 (and possibly volatile organic compounds (VOCs) as well) in the upwind coastal regions of mainland China, which is supported by the observed positive CO trend (5.23 ppbv/yr) at the site. The increase in background ozone contributed two thirds of the annual increase in ''total ozone'' in the downwind urban areas of Hong Kong, suggesting the need to consider distant sources when developing long-term strategies to mitigate local ozone pollution, although short-term strategies should be aimed at sources in Hong Kong and the adjacent Pearl River Delta.

  4. Interactions of nitrogenous air pollutants and ozone with California forests

    SciTech Connect

    Bytnerowicz, A.

    1994-12-31

    Ozone has been blamed for the decline of ponderosa and Jeffrey pines in Sierra Nevada and the San Bernardino Mountains. However, also other components of photochemical smog, and especially various nitrogenous compounds, play an important role in the observed changes in California forests. Gaseous nitric acid and peroxyacetyl nitrate may directly effects plants (development of foliar injury) or may predispose foliage to the deleterious effects of acidic wet deposition, elevated levels of the UV-B radiation or other stresses. In addition, the long-term deposition of nitrate and ammonium in wet precipitation, dry deposition of gaseous nitric acid, ammonia, nitrogen oxides, particulate nitrate and ammonium can significantly change nitrogen status of forests in California. Initially, changes in phenology of plants, higher rates of physiological processes, changed plant chemical composition, altered biochemical processes and improved growth can be observed. These changes may lead to increased susceptibility of plants to various abiotic and biotic stresses. After long periods of increased nitrogen deposition, deficiencies of calcium, magnesium, potassium, phosphorus, and other nutrients may develop. As a consequence of the elevated N deposition interacting with ozone phytotoxicity, perturbations in normal growth of plants and changes in species composition in forest stands may be taking place. Oversaturating forests with nitrogen may also result in increased nitrate content in ground water of the affected watersheds.

  5. Effects of trans-Eurasian transport of air pollutants on surface ozone concentrations over Western China

    NASA Astrophysics Data System (ADS)

    Li, Xiaoyuan; Liu, Junfeng; Mauzerall, Denise L.; Emmons, Louisa K.; Walters, Stacy; Horowitz, Larry W.; Tao, Shu

    2014-11-01

    Due to a lack of industrialization in Western China, surface air there was, until recently, believed to be relatively unpolluted. However, recent measurements and modeling studies have found high levels of ozone (O3) there. Based on the state-of-the-science global chemical transport model MOZART-4, we identify the origin, pathway, and mechanism of trans-Eurasian transport of air pollutants to Western China in 2000. MOZART-4 generally simulates well the observed surface O3 over inland areas of China. Simulations find surface ozone concentrations over Western China on average to be about 10 ppbv higher than Eastern China. Using sensitivity studies, we find that anthropogenic emissions from all Eurasian regions except China contribute 10-15 ppbv surface O3 over Western China, superimposed upon a 35-40 ppbv natural background. Transport from European anthropogenic sources to Northwestern China results in 2-6 ppbv O3 enhancements in spring and summer. Indian anthropogenic sources strongly influence O3 over the Tibetan Plateau during the summer monsoon. Transport of O3 originating from emissions in the Middle East occasionally reach Western China and increase surface ozone there by about 1-4 ppbv. These influences are of similar magnitude as trans-Pacific and transatlantic transport of O3 and its precursors, indicating the significance of trans-Eurasian ozone transport in hemispheric transport of air pollution. Our study further indicates that mitigation of anthropogenic emissions from Europe, the Indian subcontinent, and the Middle East could benefit public health and agricultural productivity in Western China.

  6. Effects of trans-Eurasian transport of anthropogenic pollutants on surface ozone concentrations over China

    NASA Astrophysics Data System (ADS)

    Liu, J.; Li, X.; Mauzerall, D. L.; Emmons, L. K.; Horowitz, L. W.; Guo, Y.; Tao, S.

    2015-12-01

    Due to a lack of industrialization in Western China, surface air there was, until recently, believed to be relatively unpolluted. However, recent measurements and modeling studies have found high levels of ozone (O3) there. Based on the state-of-the-science global chemical transport model MOZART-4, we identify the origin, pathway, and mechanism of trans-Eurasian transport of air pollutants to Western China in 2000. MOZART-4 generally simulates well the observed surface O3 over inland areas of China. Simulations find surface ozone concentrations over Western China on average to be about 10 ppbv higher than Eastern China. Using sensitivity studies as well as a fully-tagged approach, we find that anthropogenic emissions from all Eurasian regions except China contribute 10-15 ppbv surface O3 over Western China, superimposed upon a 35-40 ppbv natural background. Transport from European anthropogenic sources to Northwestern China results in 2-6 ppbv O3 enhancements in spring and summer. Indian anthropogenic sources strongly influence O3 over the Tibetan Plateau during the summer monsoon. Transport of O3 originating from emissions in the Middle East occasionally reach Western China and increase surface ozone there by about 1-4 ppbv. These influences are of similar magnitude as trans-Pacific and transatlantic transport of O3 and its precursors, indicating the significance of trans-Eurasian ozone transport in hemispheric transport of air pollution. Our study further indicates that mitigation of anthropogenic emissions from Europe, the Indian subcontinent, and the Middle East could benefit public health and agricultural productivity in Western China.

  7. INFLUENCE OF INCREASED ISOPRENE EMISSIONS ON REGIONAL OZONE MODELING

    EPA Science Inventory

    The role of biogenic hydrocarbons on ozone modeling has been a controversial issue since the 1970s. In recent years, changes in biogenic emission algorithms have resulted in large increases in estimated isoprene emissions. This paper describes a recent algorithm, the second gener...

  8. Process Analysis of Typhoon Related Ozone Pollution over the Pearl River Delta during the PRIDE-PRD2006

    NASA Astrophysics Data System (ADS)

    Li, Y.; Wang, X.; Zhang, Y.

    2014-12-01

    There were two typhoon processes during Campaign PRIDE-PRD2006 in July 2006 and serious ozone pollution episodes occurred before the landing of the typhoons. Chemical transport model CMAQ was employed in this work to simulate the ozone pollution episode related by the typhoon KAEMI. According to the meteorological conditions, the pollution episode could be divided into three phases with the movement of the typhoon, which were (1) far away from the continent; (2) coming close to the continent; (3) before landing. Process analysis was applied to get the contributions of physical and chemical processes for the ozone. It revealed that transport process was dominant during this pollution episode, and the influence of chemical process increased in the second phase. Three typical regions, northern rural area, urban area and Hong Kong area, were selected to study the contribution of each chemical and physical process. In the first phase, the primary process in northern rural area and the urban area was vertical diffusion, accounting for 47% and 46% respectively. In the second phase, the primary process in northern rural area and the urban area was chemical process, accounting for 33% and 31% respectively. In the third phase, the region of high concentration ozone moved southward. For Hong Kong area, the western inflow was prominent as 40%. Sensitivity study showed that urban areas were VOCs-limited regime with decreased ozone concentration when reducing the emission of VOCs. On the contrary, the ozone concentration in downwind rural areas decreased with the reduction of NOx, and the reason may be the decrement of the accumulated precursors.

  9. Surface Ozone over California: The Influence of Pollution Inflow

    NASA Astrophysics Data System (ADS)

    Pfister, Gabriele; Edwards, David; Emmons, Louisa

    2010-05-01

    We present results from a study that quantifies the impacts of pollution inflow on surface ozone. The focus of the analysis is on the California region and on summer 2008, when the ARCTAS-CARB aircraft campaign, a joint program between NASA and the California Air Resources Board, took place. The study integrates the global chemistry transport model MOZART-V4 with the regional WRF-Chem model. Both models employ the same chemistry scheme and emissions allowing for a high level of synergy across model scales. The global model provides time and space varying boundary conditions for the regional simulations. Aircraft measurements from the field campaign will be used together with in-situ observations from ground (U.S. EPA Air Quality Monitoring System) as well as satellite retrievals (e.g. Aura/OMI NO2 and HCHO, Aura/TES CO and O3, Terra/MOPITT CO, IASI CO) for evaluating the model simulations and supporting the analysis.

  10. Vertical distribution of ozone and nitrogenous pollutants in an air quality class I area, the San Gorgonio wilderness, southern California.

    PubMed

    Alonso, Rocío; Bytnerowicz, Andrzej; Arbaugh, Michael

    2002-01-01

    Information about spatial and temporal distribution of air pollutants is essential for better understanding of environmental stresses affecting forests and estimation of potential risks associated with air pollutants. Ozone and nitrogenous air pollutants were monitored along an elevation gradient in the Class I San Gorgonio Wilderness area (San Bernardino Mountains, California, U.S.) during the summer of 2000 (mid-June to mid-October). Passive samplers were exposed for 2-week periods at six sampling sites located at 300 m intervals ranging from 1200 to 2700 m elevation. Elevated concentrations of ozone were found in this area with summer 24-h hourly means ranging from 53 to 59 ppb. The highest ozone concentrations were detected in the period July 25-August 8, reaching values of 64 to 72 ppb expressed as 2-week mean. Passive-sampler ozone data did not show a clear relationship with elevation, although during the periods with higher ozone levels, ozone concentrations were higher at those sites below 2000 m than at sites located above that elevation. All nitrogenous pollutants studied showed a consistent decrease of concentrations with elevation. Nitrogen dioxide (NO2) levels were low, decreasing with increasing elevation from 6.4 to 1.5 ppb summer means. Nitric oxide (NO) concentrations were around 1 to 2 ppb, which is within the range of the detection levels of the devices used. Nitric acid (HNO3) vapor concentrations were lower at higher elevations (summer means 1.9-2.5 microg m(-3) than at lower elevations (summer means 4.3-5.1 microg m(-3). Summer concentrations of ammonia (NH3) were slightly higher than nitric acid ranging from 6 microg m(-3) at the lowest site to 2.5 microg m(-3) registered at the highest elevation. Since complex interactions between ozone and nitrogenous air pollutants have already been described for forests, simultaneous information about the distribution of these pollutants is needed. This is particularly important in mountain terrain where

  11. Interplay of air pollution and asthma immunopathogenesis: a focused review of diesel exhaust and ozone.

    PubMed

    Alexis, Neil E; Carlsten, Chris

    2014-11-01

    Controlled human exposure experiments with diesel exhaust particles (DEPs) and ozone serve to illustrate the important role pollutants play in modulating both allergic mechanisms and immune responses to affect the immunopathogenesis of airway diseases such as asthma. For DEP, evidence is stronger for the exacerbation of existing asthma rather than for the development of new disease. To the extent that this enhancement occurs, the augmentation of Th2-type immunity seems to be a common element. For ozone, neutrophilic inflammation, altered immune cell phenotype and function and oxidative stress are all marked responses that likely contribute to underlying immune-inflammatory features of asthma. Evidence is also emerging that unique gene signatures and epigenetic control of immune and inflammatory-based genes are playing important roles in the magnitude of the impact ozone is having on respiratory health. Indeed, the interplay between air pollutants such as DEP and ozone and asthma immunopathogenesis is an ongoing concern in terms of understanding how exposure to these agents can lead to worsening of disease. To this end, asthmatics may be pre-disposed to the deleterious effects of pollutants like ozone, having constitutively modified host defense functions and gene signatures. Although this review has utilized DEP and ozone as example pollutants, more research is needed to better understand the interplay between air pollution in general and asthma immumopathogenesis.

  12. Record-breaking ozone losses matched by record increase in ultraviolet radiation levels

    SciTech Connect

    Not Available

    1993-12-01

    For the fourth consecutive austral spring, the antarctic ozone hole broke existing records for decrease levels of ozone abundance. This article discusses the possible explainations including unusually low temperatures of the polar vortex, which may enhance ozone loss. UV increases at South Pole, McMurdo, and Palmer Stations were also discussed in conjunction with the Ozone hole.

  13. Nitrous oxide pollution from aircraft to increase by 2050

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-09-01

    The transportation industry is not only one of the biggest sources of air pollution and a significant player in greenhouse gas-induced global warming, but, as a new study shows, the industry could also be responsible for episodes of ozone (O3 ) pollution, particularly over the United States and northern Europe. Combustion of fuel in cars, shipping vessels, and low-flying aircraft produce nitrogen oxides (NOx), which not only decrease the lifetime of greenhouse gases such as methane but also react with other molecules in the atmosphere to form tropospheric O3, another, more lethal, air pollutant. Hauglustaine and Koff used a global three-dimensional chemistry-climate model to investigate how different components of the transportation industry—cars, ships, and low-flying aircraft—would contribute to NOx pollution over the next few decades under several projected emission scenarios. They found that as road transportation stagnates or even declines due to stricter regulations and congestion, NOx emissions from cars will decrease over time. However, aircraft will increase in number and could contribute between 25% and 48% of NOx emissions, which will be most severe over the United States and Europe—two regions with the highest growth rate in commercial aviation.

  14. Climate and Ozone Response to Increased Stratospheric Water Vapor

    NASA Technical Reports Server (NTRS)

    Shindell, Drew T.

    2001-01-01

    Stratospheric water vapor abundance affects ozone, surface climate, and stratospheric temperatures. From 30-50 km altitude, temperatures show global decreases of 3-6 K over recent decades. These may be a proxy for water vapor increases, as the Goddard Institute for Space Studies (GISS) climate model reproduces these trends only when stratospheric water vapor is allowed to increase. Observations suggest that stratospheric water vapor is indeed increasing, however, measurements are extremely limited in either spatial coverage or duration. The model results suggest that the observed changes may be part of a global, long-term trend. Furthermore, the required water vapor change is too large to be accounted for by increased production within the stratosphere, suggesting that ongoing climate change may be altering tropospheric input. The calculated stratospheric water vapor increase contributes an additional approximately equals 24% (approximately equals 0.2 W/m(exp 2)) to the global warming from well-mixed greenhouse gases over the past two decades. Observed ozone depletion is also better reproduced when destruction due to increased water vapor is included. If the trend continues, it could increase future global warming and impede stratospheric ozone recovery.

  15. Attribution of future US ozone pollution to regional emissions, climate change, long-range transport, and model deficiency

    NASA Astrophysics Data System (ADS)

    He, H.; Liang, X.-Z.; Lei, H.; Wuebbles, D. J.

    2014-10-01

    A regional chemical transport model (CTM) is used to quantify the relative contributions of future US ozone pollution from regional emissions, climate change, long-range transport (LRT) of pollutants, and model deficiency. After incorporating dynamic lateral boundary conditions (LBCs) from a global CTM, the representation of present-day US ozone pollution is notably improved. This nested system projects substantial surface ozone trends for 2050's: 6-10 ppbv decreases under the "clean" A1B scenario and ~15 ppbv increases under the "dirty" A1Fi scenario. Among the total trends, regional emissions changes dominate, contributing negative 20-50% in A1B and positive 20-40% in A1Fi, while LRT effects through chemical LBCs and climate changes account for respectively 15-50% and 10-30% in both scenarios. The projection uncertainty due to model biases is region dependent, ranging from -10 to 50%. It is shown that model biases of present-day simulations can propagate into future projections systematically but nonlinearly, and the accurate specification of LBCs is essential for US ozone projections.

  16. Plant volatile organic compounds (VOCs) in ozone (O3) polluted atmospheres: the ecological effects.

    PubMed

    Pinto, Delia M; Blande, James D; Souza, Silvia R; Nerg, Anne-Marja; Holopainen, Jarmo K

    2010-01-01

    Tropospheric ozone (O3) is an important secondary air pollutant formed as a result of photochemical reactions between primary pollutants, such as nitrogen oxides (NOx), and volatile organic compounds (VOCs). O3 concentrations in the lower atmosphere (troposphere) are predicted to continue increasing as a result of anthropogenic activity, which will impact strongly on wild and cultivated plants. O3 affects photosynthesis and induces the development of visible foliar injuries, which are the result of genetically controlled programmed cell death. It also activates many plant defense responses, including the emission of phytogenic VOCs. Plant emitted VOCs play a role in many eco-physiological functions. Besides protecting the plant from abiotic stresses (high temperatures and oxidative stress) and biotic stressors (competing plants, micro- and macroorganisms), they drive multitrophic interactions between plants, herbivores and their natural enemies e.g., predators and parasitoids as well as interactions between plants (plant-to-plant communication). In addition, VOCs have an important role in atmospheric chemistry. They are O3 precursors, but at the same time are readily oxidized by O3, thus resulting in a series of new compounds that include secondary organic aerosols (SOAs). Here, we review the effects of O3 on plants and their VOC emissions. We also review the state of current knowledge on the effects of ozone on ecological interactions based on VOC signaling, and propose further research directions.

  17. Ozone pollution affects flower numbers and timing in a simulated BAP priority calcareous grassland community.

    PubMed

    Hayes, Felicity; Williamson, Jennifer; Mills, Gina

    2012-04-01

    Mesocosms representing the BAP Priority habitat 'Calcareous Grassland' were exposed to eight ozone profiles for twelve-weeks in two consecutive years. Half of the mesocosms received a reduced watering regime during the exposure periods. Numbers and timing of flowering in the second exposure period were related to ozone concentration and phytotoxic ozone dose (accumulated stomatal flux). For Lotus corniculatus, ozone accelerated the timing of the maximum number of flowers. An increase in mean ozone concentration from 30ppb to 70ppb corresponded with an advance in the timing of maximum flowering by six days. A significant reduction in flower numbers with increasing ozone was found for Campanula rotundifolia and Scabiosa columbaria and the relationship with ozone was stronger for those that were well-watered than for those with reduced watering. These changes in flowering timing and numbers could have large ecological impacts, affecting plant pollination and the food supply of nectar feeding insects.

  18. Innovative reactor technology for selective oxidation of toxic organic pollutants in wastewater by ozone.

    PubMed

    Boncz, M A; Bruning, H; Rulkens, W H

    2003-01-01

    Ozonation can be a suitable technique for the pre-treatment of wastewater containing low concentrations of toxic or non-biodegradable compounds that cannot be treated with satisfactory results when only the traditional, less expensive biological techniques are applied. In this case, the oxidation process has to be made as efficient as possible, in order to reduce the coats of ozone addition and use. An efficient oxidation process with ozone can be obtained by focusing the oxidation with ozone selectively on the direct oxidation of toxic pollutants and to minimize ozone losses due to the decay of ozone in water. Supported by data of the rate constants of the reactions involved, a mathematical model was developed. It quantifies the ozone consumption by the process, and the share of ozone consumption by undesired side reactions, in several different reactor systems. Results obtained with this model indicate that a plug flow reactor (PFR) will be the most efficient design for the oxidation reactor. As an alternative, the cascaded tank reactor system (CTR), in which the ozone feed may be realized with less practical problems, might be considered. The traditional continuous flow stirred tank reactor (CFSTR) is shown to be the least efficient system.

  19. Mechanism and Trend Change of Sudden Increase of Total Ozone in Seoul

    NASA Astrophysics Data System (ADS)

    Cho, H.; Park, S.; Kim, J.; Lee, Y.; Mok, J.; Lee, Y.

    2009-12-01

    The total ozone column values have been observed by numerous satellites including TOMS and OMI, and extensive network of ground-based measurements (Dobson & Brewer Spectrophotometer etc.), over long time period over the globe, in which statistical long-term trend or ozone recovery are analyzed. In March 14th, 2006, sudden increase of the total ozone values are observed in East Asia, where the mixing ratio of ozone in ozonesonde data at Sapporo (14th Mar, 2006) increased between 10 and 15km remarkably. In general, stratospheric ozone does not change that abruptly. However from late winter to early spring, sudden increase of total ozone values were observed over the North-east Eurasian Continent and the Sea of Ohotsuku. In the beginning of this periods, observed total ozone values increased by more than 40~50 DU, compared with previous day’s value, maintaining abnormal condition for a few days. This mechanism is not understood clearly but in previous studies, this effect occurred by secondary ozone peak that is caused by Stratosphere-Troposphere Exchange (STE). To explain this phenomenon, we select the highest 5% of total ozone values observed in Seoul since 1985 and analyze the back trajectory and NCEP/NCAR reanalysis data between 10~20km at the same time. In the events of sudden total ozone increase, air parcels of 10~15km altitudes came mostly from arctic region, which is statistically evident. These `arctic origin air’ are ozone-rich in mixing ratio thus results in the secondary ozone peak and ozone enhancements in Seoul. These enhancements were occurred several times in a month. Thus, it changes the average of total ozone and climatological values, which affects the trend of stratospheric ozone recovery. In this study, using the ozonesonde and total ozone data, we separate the total ozone and sudden enhancement of ozone in Upper troposphere/ Lower Stratosphere and examine the effect of these changes on the ozone recovery trend in Seoul.

  20. Modeling of organic pollutant destruction in a stirred-tank reactor by ozonation.

    PubMed

    Cheng, J; Yang, Z R; Chen, H Q; Kuo, C H; Zappi, E M

    2001-10-01

    Destruction of organic contaminants in water by ozonation is a gas-liquid process which involves ozone mass transfer and fast irreversible chemical reactions. Ozonation reactor design and process optimizing require the modeling of the gas-liquid interactions within the reactor. In this paper a theoretical model combining the fluid dynamic and reaction kinetic parameters is proposed for predicting the destruction rates of organic pollutants in a semi-batch stirred-tank reactor by ozonation. A simple expression for the enhancement factor as our previous work has been applied to evaluate the chemical mass transfer coefficient in ozone absorption, 2,4-dichlorophenol (2,4-DCP) and 2,6-DCP or their mixture are chosen as the model compounds for simulating, and the predicted DCP concentrations are compared with some measured data.

  1. Impacts of interstate transport of pollutants on high ozone events over the Mid-Atlantic United States

    NASA Astrophysics Data System (ADS)

    Liao, Kuo-Jen; Hou, Xiangting; Baker, Debra Ratterman

    2014-02-01

    The impacts of interstate transport of anthropogenic nitrogen oxides (NOx) and volatile organic compound (VOC) emissions on peak ozone formation in four nonattainment areas (i.e., Baltimore, Philadelphia-Wilmington-Atlantic City, Pittsburgh-Beaver Valley and Washington, DC) in the Mid-Atlantic U.S. were quantified in this study. Regional air quality and sensitivities of ground-level ozone to emissions from four regions in the eastern U.S. were simulated for three summer months (June, July and August) in 2007 using the U.S. EPA's Community Multiscale Air Quality model with the decoupled direct method 3D. The emissions inventory used in this study was the 2007 Mid-Atlantic Regional Air Management Association Level 2 inventory, developed for State Implementation Plan screening modeling for the Ozone Transport Commission region. The modeling results show that responses of peak ozone levels at specific locations to emissions from EGU (i.e., electric generating unit) and non-EGU sources could be different. Therefore, emissions from EGU and non-EGU sources should be considered as two different control categories when developing regional air pollution mitigation strategies. Based on the emission inventories used in this study, reductions in anthropogenic NOx emissions (including those from EGU and non-EGU sources) from the Great Lake region as well as northeastern and southeastern U.S. would be effective for decreasing area-mean peak ozone concentrations during the summer of 2007 in the Mid-Atlantic ozone air quality nonattainment areas. The results also show that reductions in anthropogenic VOC emissions from the northeastern U.S. would also be effective for decreasing area-mean peak ozone concentrations over the Mid-Atlantic U.S. In some cases, reductions in anthropogenic NOx emissions from the Great Lake and northeastern U.S. could slightly increase area-mean peak ozone concentrations at some ozone monitors in the Pittsburgh-Beaver Valley and Washington, DC areas

  2. Organic pollutants removal in wastewater by heterogeneous photocatalytic ozonation.

    PubMed

    Xiao, Jiadong; Xie, Yongbing; Cao, Hongbin

    2015-02-01

    Heterogeneous photocatalysis and ozonation are robust advanced oxidation processes for eliminating organic contaminants in wastewater. The combination of these two methods is carried out in order to enhance the overall mineralization of refractory organics. An apparent synergism between heterogeneous photocatalysis and ozonation has been demonstrated in many literatures, which gives rise to an improvement of total organic carbon removal. The present overview dissects the heterogeneous catalysts and the influences of different operational parameters, followed by the discussion on the kinetics, mechanism, economic feasibility and future trends of this integrated technology. The enhanced oxidation rate mainly results from a large amount of hydroxyl radicals generated from a synergistically induced decomposition of dissolved ozone, besides superoxide ion radicals and the photo-induced holes. Six reaction pathways possibly exist for the generation of hydroxyl radicals in the reaction mechanism of heterogeneous photocatalytic ozonation.

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

    NASA Technical Reports Server (NTRS)

    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.

  4. Threat to future global food security from climate change and ozone air pollution

    NASA Astrophysics Data System (ADS)

    Tai, Amos P. K.; Martin, Maria Val; Heald, Colette L.

    2014-09-01

    Future food production is highly vulnerable to both climate change and air pollution with implications for global food security. Climate change adaptation and ozone regulation have been identified as important strategies to safeguard food production, but little is known about how climate and ozone pollution interact to affect agriculture, nor the relative effectiveness of these two strategies for different crops and regions. Here we present an integrated analysis of the individual and combined effects of 2000-2050 climate change and ozone trends on the production of four major crops (wheat, rice, maize and soybean) worldwide based on historical observations and model projections, specifically accounting for ozone-temperature co-variation. The projections exclude the effect of rising CO2, which has complex and potentially offsetting impacts on global food supply. We show that warming reduces global crop production by >10% by 2050 with a potential to substantially worsen global malnutrition in all scenarios considered. Ozone trends either exacerbate or offset a substantial fraction of climate impacts depending on the scenario, suggesting the importance of air quality management in agricultural planning. Furthermore, we find that depending on region some crops are primarily sensitive to either ozone (for example, wheat) or heat (for example, maize) alone, providing a measure of relative benefits of climate adaptation versus ozone regulation for food security in different regions.

  5. Increasing risk for negative ozone impacts on vegetation in northern Sweden.

    PubMed

    Karlsson, P E; Tang, L; Sundberg, J; Chen, D; Lindskog, A; Pleijel, H

    2007-11-01

    Trends were found for increasing surface ozone concentrations during April-September in northern Sweden over the period 1990-2006 as well as for an earlier onset of vegetation growing season. The highest ozone concentrations in northern Sweden occurred in April and the ozone concentrations in April showed a strong increasing trend. A model simulation of ozone flux for Norway spruce indicated that the provisional ozone flux based critical level for forests in Europe is exceeded in northern Sweden. Future climate change would have counteracting effects on the stomatal conductance and needle ozone uptake, mediated on the one hand by direct effect of increasing air temperatures and on the other through increasing water vapour pressure difference between the needles and air. Thus, there is a substantial and increasing risk for negative impacts of ozone on vegetation in northern Sweden, related mainly to increasing ozone concentrations and an earlier onset of the growing season.

  6. Ozone air pollution and ischaemic stroke occurrence: a case-crossover study in Nice, France

    PubMed Central

    Suissa, Laurent; Fortier, Mikael; Lachaud, Sylvain; Staccini, Pascal; Mahagne, Marie-Hélène

    2013-01-01

    Objectives Relationship between low-level air pollution and stroke is conflicting. This study was conducted to document the relationship between outdoor air pollution and ischaemic stroke occurrence. Design Time-stratified case-crossover analysis. Setting University Hospital of Nice, France. Participants All consecutive patients with ischaemic stroke living in Nice admitted in the University Hospital of Nice (France) between January 2007 and December 2011. Main outcome measure Association (adjusted OR) between daily levels of outdoor pollutants (ozone (O3), nitrogen dioxide (NO2), particulate matter (PM10) and sulfur dioxide (SO2)) and ischaemic stroke occurrence. Results 1729 patients with ischaemic stroke (mean age: 76.1±14.0 years; men: 46.7%) were enrolled. No significant association was found between stroke occurrence and short-term effects of all pollutants tested. In stratified analysis, we observed significant associations only between recurrent (n=280) and large artery ischaemic stroke (n=578) onset and short-term effect of O3 exposure. For an increase of 10 µg/m3 of O3 level, recurrent stroke risk (mean D-1, D-2 and D-3 lag) was increased by 12.1% (95% CI 1.5% to 23.9%) and large artery stroke risk (mean D-3 and D-4 lag) was increased by 8% (95% CI 2.0% to 16.6%). Linear dose–response relationship for both subgroups was found. Conclusions Our results confirm the relationship between low-level O3 exposure and ischaemic stroke in high vascular risk subgroup with linear exposure–response relation, independently of other pollutants and meteorological parameters. The physiopathological processes underlying this association between ischaemic stroke and O3 exposure remain to be investigated. PMID:24319276

  7. Increase in the ozone decay time in acidic ozone water and its effects on sterilization of biological warfare agents.

    PubMed

    Uhm, Han S; Hong, Yi F; Lee, Han Y; Park, Yun H

    2009-09-15

    The sterilization properties of ozone in acidic water are investigated in this study. Acidification of water increases the ozone decay time by several times compared to the decay time in neutral water, thereby enhancing the sterilization strength of ozone in acidic water. A simple analytical model involving the viable microbial counts after contact with acidic ozone water was derived, and a sterilization experiment was conducted on bacterial cells using the acidic ozone water. The acidic ozone water was found to kill very effectively endospores of Bacillus atrophaeus ATCC 9372, thereby demonstrating the potential for disinfection of a large surface area in a very short time and for reinstating the contaminated environment as free from toxic biological agents.

  8. Growth of Continental-Scale Metro-Agro-Plexes, Regional Ozone Pollution, and World Food Production

    NASA Astrophysics Data System (ADS)

    Chameides, W. L.; Kasibhatla, P. S.; Yienger, J.; Levy, H., II

    1994-04-01

    Three regions of the northern mid-latitudes, the continental-scale metro-agro-plexes, presently dominate global industrial and agricultural productivity. Although these regions cover only 23 percent of the Earth's continents, they account for most of the world's commercial energy consumption, fertilizer use, food-crop production, and food exports. They also account for more than half of the world's atmospheric nitrogen oxide (NO_x) emissions and, as a result, are prone to ground-level ozone (O_3) pollution during the summer months. On the basis of a global simulation of atmospheric reactive nitrogen compounds, it is estimated that about 10 to 35 percent of the world's grain production may occur in parts of these regions where ozone pollution may reduce crop yields. Exposure to yield-reducing ozone pollution may triple by 2025 if rising anthropogenic NO_x emissions are not abated.

  9. Environmental Pollutant Ozone Causes Damage to Lung Surfactant Protein B (SP-B)

    PubMed Central

    2015-01-01

    Lung surfactant protein B (SP-B) is an essential protein found in the surfactant fluid at the air–water interface of the lung. Exposure to the air pollutant ozone could potentially damage SP-B and lead to respiratory distress. We have studied two peptides, one consisting of the N-terminus of SP-B [SP-B(1–25)] and the other a construct of the N- and C-termini of SP-B [SP-B(1–25,63–78)], called SMB. Exposure to dilute levels of ozone (∼2 ppm) of monolayers of each peptide at the air–water interface leads to a rapid reaction, which is evident from an increase in the surface tension. Fluorescence experiments revealed that this increase in surface tension is accompanied by a loss of fluorescence from the tryptophan residue at the interface. Neutron and X-ray reflectivity experiments show that, in contrast to suggestions in the literature, the peptides are not solubilized upon oxidation but rather remain at the interface with little change in their hydration. Analysis of the product material reveals that no cleavage of the peptides occurs, but a more hydrophobic product is slowly formed together with an increased level of oligomerization. We attributed this to partial unfolding of the peptides. Experiments conducted in the presence of phospholipids reveal that the presence of the lipids does not prevent oxidation of the peptides. Our results strongly suggest that exposure to low levels of ozone gas will damage SP-B, leading to a change in its structure. The implication is that the oxidized protein will be impaired in its ability to interact at the air–water interface with negatively charged phosphoglycerol lipids, thus compromising what is thought to be its main biological function. PMID:26270023

  10. Environmental Pollutant Ozone Causes Damage to Lung Surfactant Protein B (SP-B).

    PubMed

    Hemming, Joanna M; Hughes, Brian R; Rennie, Adrian R; Tomas, Salvador; Campbell, Richard A; Hughes, Arwel V; Arnold, Thomas; Botchway, Stanley W; Thompson, Katherine C

    2015-08-25

    Lung surfactant protein B (SP-B) is an essential protein found in the surfactant fluid at the air-water interface of the lung. Exposure to the air pollutant ozone could potentially damage SP-B and lead to respiratory distress. We have studied two peptides, one consisting of the N-terminus of SP-B [SP-B(1-25)] and the other a construct of the N- and C-termini of SP-B [SP-B(1-25,63-78)], called SMB. Exposure to dilute levels of ozone (~2 ppm) of monolayers of each peptide at the air-water interface leads to a rapid reaction, which is evident from an increase in the surface tension. Fluorescence experiments revealed that this increase in surface tension is accompanied by a loss of fluorescence from the tryptophan residue at the interface. Neutron and X-ray reflectivity experiments show that, in contrast to suggestions in the literature, the peptides are not solubilized upon oxidation but rather remain at the interface with little change in their hydration. Analysis of the product material reveals that no cleavage of the peptides occurs, but a more hydrophobic product is slowly formed together with an increased level of oligomerization. We attributed this to partial unfolding of the peptides. Experiments conducted in the presence of phospholipids reveal that the presence of the lipids does not prevent oxidation of the peptides. Our results strongly suggest that exposure to low levels of ozone gas will damage SP-B, leading to a change in its structure. The implication is that the oxidized protein will be impaired in its ability to interact at the air-water interface with negatively charged phosphoglycerol lipids, thus compromising what is thought to be its main biological function. PMID:26270023

  11. Surface ozone background in the United States: Canadian and Mexican pollution influences

    NASA Astrophysics Data System (ADS)

    Wang, Huiqun; Jacob, Daniel J.; Le Sager, Philippe; Streets, David G.; Park, Rokjin J.; Gilliland, Alice B.; van Donkelaar, A.

    We use a global chemical transport model (GEOS-Chem) with 1° × 1° horizontal resolution to quantify the effects of anthropogenic emissions from Canada, Mexico, and outside North America on daily maximum 8-hour average ozone concentrations in US surface air. Simulations for summer 2001 indicate mean North American and US background concentrations of 26 ± 8 ppb and 30 ± 8 ppb, as obtained by eliminating anthropogenic emissions in North America vs. in the US only. The US background never exceeds 60 ppb in the model. The Canadian and Mexican pollution enhancement averages 3 ± 4 ppb in the US in summer but can be occasionally much higher in downwind regions of the northeast and southwest, peaking at 33 ppb in upstate New York (on a day with 75 ppb total ozone) and 18 ppb in southern California (on a day with 68 ppb total ozone). The model is successful in reproducing the observed variability of ozone in these regions, including the occurrence and magnitude of high-ozone episodes influenced by transboundary pollution. We find that exceedances of the 75 ppb US air quality standard in eastern Michigan, western New York, New Jersey, and southern California are often associated with Canadian and Mexican pollution enhancements in excess of 10 ppb. Sensitivity simulations with 2020 emission projections suggest that Canadian pollution influence in the Northeast US will become comparable in magnitude to that from domestic power plants.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. Climate Response to the Increase in Tropospheric Ozone since Preindustrial Times: A Comparison between Ozone and Equivalent CO2 Forcings

    NASA Technical Reports Server (NTRS)

    Mickley L. J.; Jacob, D. J.; Field, B. D.; Rind, D.

    2004-01-01

    We examine the characteristics of the climate response to anthropogenic changes in tropospheric ozone. Using a general circulation model, we have carried out a pair of equilibrium climate simulations with realistic present-day and preindustrial ozone distributions. We find that the instantaneous radiative forcing of 0.49 W m(sup -2) due to the increase in tropospheric ozone since preindustrial times results in an increase in global mean surface temperature of 0.28 C. The increase is nearly 0.4 C in the Northern Hemisphere and about 0.2 C in the Southern Hemisphere. The largest increases (greater than 0.8 C) are downwind of Europe and Asia and over the North American interior in summer. In the lower stratosphere, global mean temperatures decrease by about 0.2 C due to the diminished upward flux of radiation at 9.6 micrometers. The largest stratospheric cooling, up to 1.0 C, occurs over high northern latitudes in winter, with possibly important implications for the formation of polar stratospheric clouds. To identify the characteristics of climate forcing unique to tropospheric ozone, we have conducted two additional climate equilibrium simulations: one in which preindustrial tropospheric ozone concentrations were increased everywhere by 18 ppb, producing the same global radiative forcing as present-day ozone but without the heterogeneity; and one in which CO2 was decreased by 25 ppm relative to present day, with ozone at present-day values, to again produce the same global radiative forcing but with the spectral signature of CO2 rather than ozone. In the first simulation (uniform increase of ozone), the global mean surface temperature increases by 0.25 C, with an interhemispheric difference of only 0.03 C, as compared with nearly 0.2 C for the heterogeneous ozone increase. In the second simulation (equivalent CO2), the global mean surface temperature increases by 0.36 C, 30% higher than the increase from tropospheric ozone. The stronger surface warming from CO2 is

  14. Increased CCL24/eotaxin-2 with postnatal ozone exposure in allergen-sensitized infant monkeys is not associated with recruitment of eosinophils to airway mucosa

    SciTech Connect

    Chou, Debbie L.; Gerriets, Joan E.; Schelegle, Edward S.; Hyde, Dallas M.; Miller, Lisa A.

    2011-12-15

    Epidemiology supports a causal link between air pollutant exposure and childhood asthma, but the mechanisms are unknown. We have previously reported that ozone exposure can alter the anatomic distribution of CD25+ lymphocytes in airways of allergen-sensitized infant rhesus monkeys. Here, we hypothesized that ozone may also affect eosinophil trafficking to allergen-sensitized infant airways. To test this hypothesis, we measured blood, lavage, and airway mucosa eosinophils in 3-month old monkeys following cyclical ozone and house dust mite (HDM) aerosol exposures. We also determined if eotaxin family members (CCL11, CCL24, CCL26) are associated with eosinophil location in response to exposures. In lavage, eosinophil numbers increased in animals exposed to ozone and/or HDM. Ozone + HDM animals showed significantly increased CCL24 and CCL26 protein in lavage, but the concentration of CCL11, CCL24, and CCL26 was independent of eosinophil number for all exposure groups. In airway mucosa, eosinophils increased with exposure to HDM alone; comparatively, ozone and ozone + HDM resulted in reduced eosinophils. CCL26 mRNA and immunofluorescence staining increased in airway mucosa of HDM alone animals and correlated with eosinophil volume. In ozone + HDM animal groups, CCL24 mRNA and immunofluorescence increased along with CCR3 mRNA, but did not correlate with airway mucosa eosinophils. Cumulatively, our data indicate that ozone exposure results in a profile of airway eosinophil migration that is distinct from HDM mediated pathways. CCL24 was found to be induced only by combined ozone and HDM exposure, however expression was not associated with the presence of eosinophils within the airway mucosa. -- Highlights: Black-Right-Pointing-Pointer Ozone can modulate the localization of eosinophils in infant allergic airways. Black-Right-Pointing-Pointer Expression of eotaxins within the lung is affected by ozone and allergen exposure. Black-Right-Pointing-Pointer CCL24 induction by

  15. How do increasing background concentrations of tropospheric ozone affect peatland plant growth and carbon gas exchange?

    NASA Astrophysics Data System (ADS)

    Williamson, Jennifer L.; Mills, Gina; Hayes, Felicity; Jones, Timothy; Freeman, Chris

    2016-02-01

    In this study we have demonstrated that plants originating from upland peat bogs are sensitive to increasing background concentrations of ozone. Peatland mesocosms from an upland peat bog in North Wales, UK were exposed to eight levels of elevated background ozone in solardomes for 4 months from May to August, with 24 h mean ozone concentrations ranging from 16 to 94 ppb and cumulative AOT024hr ranging from 45.98 ppm h to 259.63 ppm h. Our results show that plant senescence increased with increasing exposure to ozone, although there was no significant effect of increasing ozone on plant biomass. Assessments of carbon dioxide and methane fluxes from the mesocosms suggests that there was no change in carbon dioxide fluxes over the 4 month exposure period but that methane fluxes increased as cumulative ozone exposure increased to a maximum AOT 024hr of approximately 120 ppm h and then decreased as cumulative ozone exposure increased further.

  16. Flixweed Is More Competitive than Winter Wheat under Ozone Pollution: Evidences from Membrane Lipid Peroxidation, Antioxidant Enzymes and Biomass

    PubMed Central

    Li, Yong; Zheng, Yan-Hai; Jiang, Gao-Ming

    2013-01-01

    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. PMID:23533669

  17. The impact of observing characteristics on the ability to predict ozone under varying polluted photochemical regimes

    NASA Astrophysics Data System (ADS)

    Hamer, P. D.; Bowman, K. W.; Henze, D.; Attié, J.-L.; Marécal, V.

    2015-02-01

    We conduct a variety of analyses to assess how the characteristics of observations of ozone and its precursors affect their ability to support air quality forecasting and research. To carry out this investigation we use a photochemical box model and its adjoint integrated with a Lagrangian 4-D-variational data assimilation system. Using this framework in conjunction with various sets of pseudo observations we perform a ozone precursor source inversion and estimate surface emissions. We then assess the resulting improvement in ozone air quality forecasting and prediction. We use an analytical model as our principle method of conducting uncertainty analyses, which is the primary focus of this work. Using this analytical tool we address some simple but key questions regarding how the characteristics of observations affect our framework's ability to constrain ozone precursor emissions and in turn to predict ozone. These questions include what the effect is of choosing which species to observe, of varying amounts of observation noise, of changing the observing frequency and the observation time during the diurnal cycle, and of how these different scenarios interact with different photochemical regimes. These questions are designed to examine how different types of observing platform, e.g., geostationary satellites or ground monitoring networks, could support future air quality research and forecasting. In our investigation we use three observed species scenarios: CO and NO2; ozone, CO, and NO2; and HCHO, CO and NO2. The photochemical model was setup to simulate a range of summertime polluted environments spanning NOx (NO and NO2) limited to volatile organic compound (VOC) limited conditions. We find that as the photochemical regime changes the relative importance of trace gas observations to constrain emission estimates and subsequent ozone forecasts varies. For example, adding ozone observations to an NO2 and CO observing system is found to decrease ozone prediction

  18. Sensitivity analysis of ozone formation and transport for a Central California air pollution episode

    SciTech Connect

    Jin, Ling; Tonse, Shaheen; Cohan, Daniel S.; Mao, Xiaoling; Harley, Robert A.; Brown, Nancy J.

    2009-05-15

    CMAQ-HDDM is used to determine spatial and temporal variations in ozone limiting reagents and local vs upwind source contributions for an air pollution episode in Central California. We developed a first- and second- order sensitivity analysis approach with the Decoupled Direct Method to examine spatial and temporal variations of ozone-limiting reagents and the importance of local vs upwind emission sources in the San Joaquin Valley of central California for a five-day ozone episode (29th July-3rd Aug, 2000). Despite considerable spatial variations, nitrogen oxides (NO{sub x}) emission reductions are overall more effective than volatile organic compound (VOC) control for attaining the 8-hr ozone standard in this region for this episode, in contrast to the VOC control that works better for attaining the prior 1-hr ozone standard. Inter-basin source contributions of NO{sub x} emissions are limited to the northern part of the SJV, while anthropogenic VOC (AVOC) emissions, especially those emitted at night, influence ozone formation in the SJV further downwind. Among model input parameters studied here, uncertainties in emissions of NO{sub x} and AVOC, and the rate coefficient of the OH + NO{sub 2} termination reaction, have the greatest effect on first-order ozone responses to changes in NO{sub x} emissions. Uncertainties in biogenic VOC emissions only have a modest effect because they are generally not collocated with anthropogenic sources in this region.

  19. Laboratory measurement of secondary pollutant yields from ozone reaction with HVAC filters.

    SciTech Connect

    Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie; Zhang, Jianshun; Fisk, William J.

    2009-09-09

    We used Proton Transfer Reaction - Mass Spectrometry (PTR-MS) and conventional sampling methods to monitor and identify trace level organic pollutants formed in heterogeneous reactions between ozone and HVAC filters in real time. Experiments were carried out using a bench-scale flow tube reactor operating with dry air and humidified air (50% RH), at realistically high ozone concentrations (150 ppbv). We explored different filter media (i.e., fiberglass and cotton/polyester blends) and different particle loadings (i.e., clean filter and filters loaded with particles for 3 months at the Lawrence Berkeley National Laboratory and the Port of Oakland, CA). Detailed emission dynamics of very low levels of certain organic pollutants from filter media upon ozone exposure in the presence of moisture have been obtained and analyzed.

  20. Global health benefits of mitigating ozone pollution with methane emission controls.

    PubMed

    West, J Jason; Fiore, Arlene M; Horowitz, Larry W; Mauzerall, Denise L

    2006-03-14

    Methane (CH(4)) contributes to the growing global background concentration of tropospheric ozone (O(3)), an air pollutant associated with premature mortality. Methane and ozone are also important greenhouse gases. Reducing methane emissions therefore decreases surface ozone everywhere while slowing climate warming, but although methane mitigation has been considered to address climate change, it has not for air quality. Here we show that global decreases in surface ozone concentrations, due to methane mitigation, result in substantial and widespread decreases in premature human mortality. Reducing global anthropogenic methane emissions by 20% beginning in 2010 would decrease the average daily maximum 8-h surface ozone by approximately 1 part per billion by volume globally. By using epidemiologic ozone-mortality relationships, this ozone reduction is estimated to prevent approximately 30,000 premature all-cause mortalities globally in 2030, and approximately 370,000 between 2010 and 2030. If only cardiovascular and respiratory mortalities are considered, approximately 17,000 global mortalities can be avoided in 2030. The marginal cost-effectiveness of this 20% methane reduction is estimated to be approximately 420,000 US dollars per avoided mortality. If avoided mortalities are valued at 1 US dollars million each, the benefit is approximately 240 US dollars per tone of CH(4) ( approximately 12 US dollars per tone of CO(2) equivalent), which exceeds the marginal cost of the methane reduction. These estimated air pollution ancillary benefits of climate-motivated methane emission reductions are comparable with those estimated previously for CO(2). Methane mitigation offers a unique opportunity to improve air quality globally and can be a cost-effective component of international ozone management, bringing multiple benefits for air quality, public health, agriculture, climate, and energy.

  1. Cardiovascular effects of diesel exhaust and ozone in a multi-pollutant context

    EPA Science Inventory

    The cardiovascular effects of two common pollutants, diesel exhaust (DE) and ozone (O3), were examined alone and in combination. Healthy subjects (n=15) were exposed for 2 hrs with intermittent, moderate exercise on Day 1 to 0.3 ppm O3, 300 µg/m3 DE, both O3 and DE, or fil...

  2. Web-Based Tools for Modelling and Analysis of Multivariate Data: California Ozone Pollution Activity

    ERIC Educational Resources Information Center

    Dinov, Ivo D.; Christou, Nicolas

    2011-01-01

    This article presents a hands-on web-based activity motivated by the relation between human health and ozone pollution in California. This case study is based on multivariate data collected monthly at 20 locations in California between 1980 and 2006. Several strategies and tools for data interrogation and exploratory data analysis, model fitting…

  3. Ozone pollution effects on the land carbon sink in the future greenhouse world

    NASA Astrophysics Data System (ADS)

    Unger, N.; Yue, X.

    2015-12-01

    Ozone pollution has huge impacts on the carbon balance in the United States, Europe and China. While terrestrial ecosystems provide an important sink for surface ozone through stomatal uptake, this process damages photosynthesis, reduces plant growth and biomass accumulation, and affects stomatal control over plant transpiration of water vapor. Effective mitigation of climate change by stabilizing atmospheric carbon dioxide concentrations requires improved understanding of ozone effects on the land carbon sink. Future effects of ozone pollution on the land carbon sink are largely unknown. We apply multiple observational datasets in combination with the Yale Interactive Terrestrial Biosphere (YIBs) model to quantify ozone vegetation damage in the present climatic state and for a broad range of possible futures. YIBs includes a mechanistic ozone damage model that affects both photosynthetic rate and stomatal conductance for low or high ozone plant sensitivity. YIBs is embedded in the NASA GISS ModelE2 global chemistry-climate model to allow a uniquely informed integration of plant physiology, atmospheric chemistry, and climate. The YIBs model has been extensively evaluated using land carbon flux measurements from 145 flux tower sites and multiple satellite products. Chronic ozone exposure in the present day reduces GPP by 11-23%, NPP by 8-16%, stomatal conductance by 8-17% and leaf area index by 2-5% in the summer time eastern United States. Similar response magnitudes are found in Europe but almost doubled damage effects occur in hotspots in eastern China. We investigate future ozone vegetation damage within the context of multiple global change drivers (physical climate change, carbon dioxide fertilization, human energy and agricultural emissions, human land use) at 2050 following the IPCC RCP2.6 and RCP8.5 scenarios. In the RCP8.5 world at 2050, growing season average GPP and NPP are reduced by 20-40% in China and 5-20% in the United States due to the global rise

  4. Impacts of Climate Change on Surface Ozone and Intercontinental Ozone Pollution: A Multi-Model Study

    NASA Technical Reports Server (NTRS)

    Doherty, R. M.; Wild, O.; Shindell, D. T.; Zeng, G.; MacKenzie, I. A.; Collins, W. J.; Fiore, A. M.; Stevenson, D. S.; Dentener, F. J.; Schultz, M. G.; Hess, P.; Derwent, R. G.; Keating, T. J.

    2013-01-01

    The impact of climate change between 2000 and 2095 SRES A2 climates on surface ozone (O)3 and on O3 source-receptor (S-R) relationships is quantified using three coupled climate-chemistry models (CCMs). The CCMs exhibit considerable variability in the spatial extent and location of surface O3 increases that occur within parts of high NOx emission source regions (up to 6 ppbv in the annual average and up to 14 ppbv in the season of maximum O3). In these source regions, all three CCMs show a positive relationship between surface O3 change and temperature change. Sensitivity simulations show that a combination of three individual chemical processes-(i) enhanced PAN decomposition, (ii) higher water vapor concentrations, and (iii) enhanced isoprene emission-largely reproduces the global spatial pattern of annual-mean surface O3 response due to climate change (R2 = 0.52). Changes in climate are found to exert a stronger control on the annual-mean surface O3 response through changes in climate-sensitive O3 chemistry than through changes in transport as evaluated from idealized CO-like tracer concentrations. All three CCMs exhibit a similar spatial pattern of annual-mean surface O3 change to 20% regional O3 precursor emission reductions under future climate compared to the same emission reductions applied under present-day climate. The surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions. All three CCMs show areas within Europe where regional emission reductions larger than 20% are required to compensate climate change impacts on annual-mean surface O3.

  5. Impacts of climate change on surface ozone and intercontinental ozone pollution: A multi-model study

    NASA Astrophysics Data System (ADS)

    Doherty, R. M.; Wild, O.; Shindell, D. T.; Zeng, G.; MacKenzie, I. A.; Collins, W. J.; Fiore, A. M.; Stevenson, D. S.; Dentener, F. J.; Schultz, M. G.; Hess, P.; Derwent, R. G.; Keating, T. J.

    2013-05-01

    impact of climate change between 2000 and 2095 SRES A2 climates on surface ozone (O)3 and on O3 source-receptor (S-R) relationships is quantified using three coupled climate-chemistry models (CCMs). The CCMs exhibit considerable variability in the spatial extent and location of surface O3 increases that occur within parts of high NOx emission source regions (up to 6 ppbv in the annual average and up to 14 ppbv in the season of maximum O3). In these source regions, all three CCMs show a positive relationship between surface O3 change and temperature change. Sensitivity simulations show that a combination of three individual chemical processes - (i) enhanced PAN decomposition, (ii) higher water vapor concentrations, and (iii) enhanced isoprene emission - largely reproduces the global spatial pattern of annual-mean surface O3 response due to climate change (R2 = 0.52). Changes in climate are found to exert a stronger control on the annual-mean surface O3 response through changes in climate-sensitive O3 chemistry than through changes in transport as evaluated from idealized CO-like tracer concentrations. All three CCMs exhibit a similar spatial pattern of annual-mean surface O3 change to 20% regional O3 precursor emission reductions under future climate compared to the same emission reductions applied under present-day climate. The surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions. All three CCMs show areas within Europe where regional emission reductions larger than 20% are required to compensate climate change impacts on annual-mean surface O3.

  6. Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China.

    PubMed

    Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

    2015-01-01

    Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations. PMID:26121146

  7. Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China.

    PubMed

    Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

    2015-01-01

    Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations.

  8. Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

    PubMed Central

    Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

    2015-01-01

    Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations. PMID:26121146

  9. Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas.

    PubMed

    Ahmadi, Mahdi; John, Kuruvilla

    2015-12-01

    Over the past decade, substantial growth in shale gas exploration and production across the US has changed the country's energy outlook. Beyond its economic benefits, the negative impacts of shale gas development on air and water are less well known. In this study the relationship between shale gas activities and ground-level ozone pollution was statistically evaluated. The Dallas-Fort Worth (DFW) area in north-central Texas was selected as the study region. The Barnett Shale, which is one the most productive and fastest growing shale gas fields in the US, is located in the western half of DFW. Hourly meteorological and ozone data were acquired for fourteen years from monitoring stations established and operated by the Texas Commission on Environmental Quality (TCEQ). The area was divided into two regions, the shale gas region (SGR) and the non-shale gas (NSGR) region, according to the number of gas wells in close proximity to each monitoring site. The study period was also divided into 2000-2006 and 2007-2013 because the western half of DFW has experienced significant growth in shale gas activities since 2007. An evaluation of the raw ozone data showed that, while the overall trend in the ozone concentration was down over the entire region, the monitoring sites in the NSGR showed an additional reduction of 4% in the annual number of ozone exceedance days than those in the SGR. Directional analysis of ozone showed that the winds blowing from areas with high shale gas activities contributed to higher ozone downwind. KZ-filtering method and linear regression techniques were used to remove the effects of meteorological variations on ozone and to construct long-term and short-term meteorologically adjusted (M.A.) ozone time series. The mean value of all M.A. ozone components was 8% higher in the sites located within the SGR than in the NSGR. These findings may be useful for understanding the overall impact of shale gas activities on the local and regional ozone

  10. Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas.

    PubMed

    Ahmadi, Mahdi; John, Kuruvilla

    2015-12-01

    Over the past decade, substantial growth in shale gas exploration and production across the US has changed the country's energy outlook. Beyond its economic benefits, the negative impacts of shale gas development on air and water are less well known. In this study the relationship between shale gas activities and ground-level ozone pollution was statistically evaluated. The Dallas-Fort Worth (DFW) area in north-central Texas was selected as the study region. The Barnett Shale, which is one the most productive and fastest growing shale gas fields in the US, is located in the western half of DFW. Hourly meteorological and ozone data were acquired for fourteen years from monitoring stations established and operated by the Texas Commission on Environmental Quality (TCEQ). The area was divided into two regions, the shale gas region (SGR) and the non-shale gas (NSGR) region, according to the number of gas wells in close proximity to each monitoring site. The study period was also divided into 2000-2006 and 2007-2013 because the western half of DFW has experienced significant growth in shale gas activities since 2007. An evaluation of the raw ozone data showed that, while the overall trend in the ozone concentration was down over the entire region, the monitoring sites in the NSGR showed an additional reduction of 4% in the annual number of ozone exceedance days than those in the SGR. Directional analysis of ozone showed that the winds blowing from areas with high shale gas activities contributed to higher ozone downwind. KZ-filtering method and linear regression techniques were used to remove the effects of meteorological variations on ozone and to construct long-term and short-term meteorologically adjusted (M.A.) ozone time series. The mean value of all M.A. ozone components was 8% higher in the sites located within the SGR than in the NSGR. These findings may be useful for understanding the overall impact of shale gas activities on the local and regional ozone

  11. Ozone in the Atmosphere: II. The Lower Atmosphere.

    ERIC Educational Resources Information Center

    Phillips, Paul; Pickering, Pam

    1991-01-01

    Described are the problems caused by the increased concentration of ozone in the lower atmosphere. Photochemical pollution, mechanisms of ozone production, ozone levels in the troposphere, effects of ozone on human health and vegetation, ozone standards, and control measures are discussed. (KR)

  12. Evaluation of emission control strategies to reduce ozone pollution in the Paso del Norte region using a photochemical air quality modeling system

    NASA Astrophysics Data System (ADS)

    Valenzuela, Victor Hugo

    Air pollution emissions control strategies to reduce ozone precursor pollutants are analyzed by applying a photochemical modeling system. Simulations of air quality conditions during an ozone episode which occurred in June, 2006 are undertaken by increasing or reducing area source emissions in Ciudad Juarez, Chihuahua, Mexico. Two air pollutants are primary drivers in the formation of tropospheric ozone. Oxides of nitrogen (NOx) and volatile organic compounds (VOC) undergo multiple chemical reactions under favorable meteorological conditions to form ozone, which is a secondary pollutant that irritates respiratory systems in sensitive individuals especially the elderly and young children. The U.S. Environmental Protection Agency established National Ambient Air Quality Standards (NAAQS) to limit ambient air pollutants such as ozone by establishing an 8-hour average concentration of 0.075 ppm as the threshold at which a violation of the standard occurs. Ozone forms primarily due reactions in the troposphere of NOx and VOC emissions generated primarily by anthropogenic sources in urban regions. Data from emissions inventories indicate area sources account for ˜15 of NOx and ˜45% of regional VOC emissions. Area sources include gasoline stations, automotive paint bodyshops and nonroad mobile sources. Multiplicity of air pollution emissions sources provides an opportunity to investigate and potentially implement air quality improvement strategies to reduce emissions which contribute to elevated ozone concentrations. A baseline modeling scenario was established using the CAMx photochemical air quality model from which a series of sensitivity analyses for evaluating air quality control strategies were conducted. Modifications to area source emissions were made by varying NOx and / or VOC emissions in the areas of particular interest. Model performance was assessed for each sensitivity analysis. Normalized bias (NB) and normalized error (NE) were used to identify

  13. Integrated assessment modeling of atmospheric pollutants in the Southern Appalachian Mountains. Part I: hourly and seasonal ozone.

    PubMed

    Boylan, James W; Odman, Mehmet T; Wilkinson, James G; Russell, Armistead G; Doty, Kevin G; Norris, William B; McNider, Richard T

    2005-07-01

    Recently, a comprehensive air quality modeling system was developed as part of the Southern Appalachians Mountains Initiative (SAMI) with the ability to simulate meteorology, emissions, ozone, size- and composition-resolved particulate matter, and pollutant deposition fluxes. As part of SAMI, the RAMS/EMS-95/URM-1ATM modeling system was used to evaluate potential emission control strategies to reduce atmospheric pollutant levels at Class I areas located in the Southern Appalachians Mountains. This article discusses the details of the ozone model performance and the methodology that was used to scale discrete episodic pollutant levels to seasonal and annual averages. The daily mean normalized bias and error for 1-hr and 8-hr ozone were within U.S. Environment Protection Agency guidance criteria for urban-scale modeling. The model typically showed a systematic overestimation for low ozone levels and an underestimation for high levels. Because SAMI was primarily interested in simulating the growing season ozone levels in Class I areas, daily and seasonal cumulative ozone exposure, as characterized by the W126 index, were also evaluated. The daily ozone W126 performance was not as good as the hourly ozone performance; however, the seasonal ozone W126 scaled up from daily values was within 17% of the observations at two typical Class I areas of the SAMI region. The overall ozone performance of the model was deemed acceptable for the purposes of SAMI's assessment. PMID:16111143

  14. Identifying sources of ozone to three rural locations in Nevada, USA, using ancillary gas pollutants, aerosol chemistry, and mercury.

    PubMed

    Miller, Matthieu B; Fine, Rebekka; Pierce, Ashley M; Gustin, Mae S

    2015-10-15

    Ozone (O3) is a secondary air pollutant of long standing and increasing concern for environmental and human health, and as such, the US Environmental Protection Agency will revise the National Ambient Air Quality Standard of 75 ppbv to ≤ 70 ppbv. Long term measurements at the Great Basin National Park (GBNP) indicate that O3 in remote areas of Nevada will exceed a revised standard. As part of the Nevada Rural Ozone Initiative, measurements of O3 and other air pollutants were made at 3 remote sites between February 2012 and March 2014, GBNP, Paradise Valley (PAVA), and Echo Peak (ECHO). Exceptionally high concentrations of each air pollutant were defined relative to each site as mixing ratios that exceeded the 90th percentile of all hourly data. Case studies were analyzed for all periods during which mean daily O3 exceeded the 90th percentile concurrently with a maximum 8-h average (MDA8) O3 that was "exceptionally high" for the site (65 ppbv at PAVA, 70 ppbv at ECHO and GBNP), and of potential regulatory significance. An MDA8 ≥ 65 ppbv occurred only five times at PAVA, whereas this occurred on 49 and 65 days at GBNP and ECHO, respectively. The overall correlation between O3 and other pollutants was poor, consistent with the large distance from significant primary emission sources. Mean CO at these locations exceeded concentrations reported for background sites in 2000. Trajectory residence time calculations and air pollutant concentrations indicate that exceedances at GBNP and ECHO were promoted by air masses originating from multiple sources, including wildfires, transport of pollution from southern California and the marine boundary layer, and transport of Asian pollution plumes. Results indicate that the State of Nevada will exceed a revised O3 standard due to sources that are beyond their control. PMID:25957787

  15. Identifying sources of ozone to three rural locations in Nevada, USA, using ancillary gas pollutants, aerosol chemistry, and mercury.

    PubMed

    Miller, Matthieu B; Fine, Rebekka; Pierce, Ashley M; Gustin, Mae S

    2015-10-15

    Ozone (O3) is a secondary air pollutant of long standing and increasing concern for environmental and human health, and as such, the US Environmental Protection Agency will revise the National Ambient Air Quality Standard of 75 ppbv to ≤ 70 ppbv. Long term measurements at the Great Basin National Park (GBNP) indicate that O3 in remote areas of Nevada will exceed a revised standard. As part of the Nevada Rural Ozone Initiative, measurements of O3 and other air pollutants were made at 3 remote sites between February 2012 and March 2014, GBNP, Paradise Valley (PAVA), and Echo Peak (ECHO). Exceptionally high concentrations of each air pollutant were defined relative to each site as mixing ratios that exceeded the 90th percentile of all hourly data. Case studies were analyzed for all periods during which mean daily O3 exceeded the 90th percentile concurrently with a maximum 8-h average (MDA8) O3 that was "exceptionally high" for the site (65 ppbv at PAVA, 70 ppbv at ECHO and GBNP), and of potential regulatory significance. An MDA8 ≥ 65 ppbv occurred only five times at PAVA, whereas this occurred on 49 and 65 days at GBNP and ECHO, respectively. The overall correlation between O3 and other pollutants was poor, consistent with the large distance from significant primary emission sources. Mean CO at these locations exceeded concentrations reported for background sites in 2000. Trajectory residence time calculations and air pollutant concentrations indicate that exceedances at GBNP and ECHO were promoted by air masses originating from multiple sources, including wildfires, transport of pollution from southern California and the marine boundary layer, and transport of Asian pollution plumes. Results indicate that the State of Nevada will exceed a revised O3 standard due to sources that are beyond their control.

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

    NASA Technical Reports Server (NTRS)

    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.

  17. Stress ethylene evolution of bean plants—a parameter indicating ozone pollution

    NASA Astrophysics Data System (ADS)

    Stan, Hans-Jürgen; Schicker, Sieglinde; Kassner, Helmut

    Bean plants treated with varying ozone concentrations for varying exposure times showed increased rates of ethylene production compared with controls. A standard method was worked out in which primary leaves of bean plants were encapsulated in 250 ml Erlenmeyer flasks after exposure. The amount of ethylene produced was determined by gas chromatography after about 24 h. The 'no effect level' of the bean plant was found to be 100 ppb ozone because there was no significant stress ethylene production even after 12 h fumigation. A treatment with 150 ppb ozone induced the beginning of stress ethylene production after about 8 h. With higher ozone concentrations shorter exposure times are necessary to induce a first response. Stress ethylene production correlates better with ozone concentration than with exposure time comparing the same products of concentration and time.

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

    NASA Astrophysics Data System (ADS)

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

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

  19. Pulsed corona discharge: the role of ozone and hydroxyl radical in aqueous pollutants oxidation.

    PubMed

    Preis, S; Panorel, I C; Kornev, I; Hatakka, H; Kallas, J

    2013-01-01

    Ozone and hydroxyl radical are the most active oxidizing species in water treated with gas-phase pulsed corona discharge (PCD). The ratio of the species dependent on the gas phase composition and treated water contact surface was the objective for the experimental research undertaken for aqueous phenol (fast reaction) and oxalic acid (slow reaction) solutions. The experiments were carried out in the reactor, where aqueous solutions showered between electrodes were treated with 100-ns pulses of 20 kV voltage and 400 A current amplitude. The role of ozone increased with increasing oxygen concentration and the oxidation reaction rate. The PCD treatment showed energy efficiency surpassing that of conventional ozonation.

  20. [Ozone source apportionment at urban area during a typical photochemical pollution episode in the summer of 2013 in the Yangtze River Delta].

    PubMed

    Li, Hao; Li, Li; Huang, Cheng; An, Jing-yu; Yan, Ru-sha; Huang, Hai-ying; Wang, Yang-jun; Lu, Qing; Wang, Qian; Lou, Sheng-rong; Wang, Hong-li; Zhou, Min; Tao, Shi-kang; Qiao, Li-ping; Chen, Ming-hua

    2015-01-01

    With the fast development of urbanization, industrialization and mobilization, the air pollutant emissions with photochemical reactivity become more obvious, causing a severe photochemical pollution with the characteristics of high ozone concentration. However, the ozone source identification is very complicated due to the high non linearity between ozone and its precursors. Thus, ways to reduce ozone is still not clear. A high ozone pollution episode occurred during July, 2013, which lasted for a long period, with large influence area and high intensity. In this paper, we selected this episode to do a case study with the application of ozone source apportionment technology(OSAT) coupled within the CAMx air quality model. In this study, 4 source regions(including Shanghai, north Zhejiang, South Jiangsu and long range transport), 7 source categories (including power plants, industrial process, industrial boilers and kilns, residential, mobile source, volatile source and biogenic emissions) are analyzed to study their contributions to surface O3 in Shanghai, Suzhou and Zhejiang. Results indicate that long range transport contribution to the surface ozone in the YRD is around 20 x 10(-9) - 40 x 10(-9) (volume fraction). The O3 concentrations can increased to 40 x 10(-9) - 100 x 10(-9) (volume fraction) due to precursors emissions in Shanghai, Jiangsu and Zhejiang. As for the regional contribution to 8 hour ozone, long range transport constitutes 42.79% +/- 10.17%, 48.57% +/- 9.97% and 60.13% +/- 7.11% of the surface ozone in Shanghai, Suzhou and Hangzhou, respectively. Regarding the high O3 in Shanghai, local contribution is 28.94% +/- 8.49%, north Zhejiang constitutes 19.83% +/- 10.55%. As for surface O3 in Suzhou, the contribution from south Jiangsu is 26.41% +/- 6.80%. Regarding the surface O3 in Hangzhou, the major regional contributor is north Zhejiang (29.56% +/- 8.33%). Contributions from the long range transport to the daily maximum O3 concentrations are

  1. [Ozone source apportionment at urban area during a typical photochemical pollution episode in the summer of 2013 in the Yangtze River Delta].

    PubMed

    Li, Hao; Li, Li; Huang, Cheng; An, Jing-yu; Yan, Ru-sha; Huang, Hai-ying; Wang, Yang-jun; Lu, Qing; Wang, Qian; Lou, Sheng-rong; Wang, Hong-li; Zhou, Min; Tao, Shi-kang; Qiao, Li-ping; Chen, Ming-hua

    2015-01-01

    With the fast development of urbanization, industrialization and mobilization, the air pollutant emissions with photochemical reactivity become more obvious, causing a severe photochemical pollution with the characteristics of high ozone concentration. However, the ozone source identification is very complicated due to the high non linearity between ozone and its precursors. Thus, ways to reduce ozone is still not clear. A high ozone pollution episode occurred during July, 2013, which lasted for a long period, with large influence area and high intensity. In this paper, we selected this episode to do a case study with the application of ozone source apportionment technology(OSAT) coupled within the CAMx air quality model. In this study, 4 source regions(including Shanghai, north Zhejiang, South Jiangsu and long range transport), 7 source categories (including power plants, industrial process, industrial boilers and kilns, residential, mobile source, volatile source and biogenic emissions) are analyzed to study their contributions to surface O3 in Shanghai, Suzhou and Zhejiang. Results indicate that long range transport contribution to the surface ozone in the YRD is around 20 x 10(-9) - 40 x 10(-9) (volume fraction). The O3 concentrations can increased to 40 x 10(-9) - 100 x 10(-9) (volume fraction) due to precursors emissions in Shanghai, Jiangsu and Zhejiang. As for the regional contribution to 8 hour ozone, long range transport constitutes 42.79% +/- 10.17%, 48.57% +/- 9.97% and 60.13% +/- 7.11% of the surface ozone in Shanghai, Suzhou and Hangzhou, respectively. Regarding the high O3 in Shanghai, local contribution is 28.94% +/- 8.49%, north Zhejiang constitutes 19.83% +/- 10.55%. As for surface O3 in Suzhou, the contribution from south Jiangsu is 26.41% +/- 6.80%. Regarding the surface O3 in Hangzhou, the major regional contributor is north Zhejiang (29.56% +/- 8.33%). Contributions from the long range transport to the daily maximum O3 concentrations are

  2. Increasing global agricultural production by reducing ozone damages via methane emission controls and ozone-resistant cultivar selection

    PubMed Central

    Avnery, Shiri; Mauzerall, Denise L; Fiore, Arlene M

    2013-01-01

    Meeting the projected 50% increase in global grain demand by 2030 without further environmental degradation poses a major challenge for agricultural production. Because surface ozone (O3) has a significant negative impact on crop yields, one way to increase future production is to reduce O3-induced agricultural losses. We present two strategies whereby O3 damage to crops may be reduced. We first examine the potential benefits of an O3 mitigation strategy motivated by climate change goals: gradual emission reductions of methane (CH4), an important greenhouse gas and tropospheric O3 precursor that has not yet been targeted for O3 pollution abatement. Our second strategy focuses on adapting crops to O3 exposure by selecting cultivars with demonstrated O3 resistance. We find that the CH4 reductions considered would increase global production of soybean, maize, and wheat by 23–102 Mt in 2030 – the equivalent of a ∼2–8% increase in year 2000 production worth $3.5–15 billion worldwide (USD2000), increasing the cost effectiveness of this CH4 mitigation policy. Choosing crop varieties with O3 resistance (relative to median-sensitivity cultivars) could improve global agricultural production in 2030 by over 140 Mt, the equivalent of a 12% increase in 2000 production worth ∼$22 billion. Benefits are dominated by improvements for wheat in South Asia, where O3-induced crop losses would otherwise be severe. Combining the two strategies generates benefits that are less than fully additive, given the nature of O3 effects on crops. Our results demonstrate the significant potential to sustainably improve global agricultural production by decreasing O3-induced reductions in crop yields. PMID:23504903

  3. Ozone Bioindicator Gardens: an Educational Tool to Raise Awareness about Environmental Pollution and its Effects on Living Systems

    NASA Astrophysics Data System (ADS)

    Lapina, K.; Lombardozzi, D.

    2014-12-01

    High concentrations of ground-level ozone cause health problems in humans and a number of negative effects on plants, from reduced yield for major agricultural crops to reduced amounts of carbon stored in trees. The Denver Metro/Colorado Front Range is exceeding the National Ambient Air Quality Standard for ozone on a regular basis in summer and the efforts to reduce the ozone levels are hampered by the presence of diverse pollution sources and complex meteorology in the region. To raise public awareness of air quality in the Colorado Front Range and to educate all age groups about ground-level ozone, two ozone bioindicator gardens were planted in Boulder in Spring 2014. The gardens contain ozone-sensitive plants that develop a characteristic ozone injury when exposed to high levels of ozone. The ozone gardens are providing the general public with a real-life demonstration of the negative effects of ozone pollution through observable plant damage. Additionally, the gardens are useful in teaching students how to collect and analyze real-world scientific data.

  4. Web-based tools for modelling and analysis of multivariate data: California ozone pollution activity

    PubMed Central

    Dinov, Ivo D.; Christou, Nicolas

    2014-01-01

    This article presents a hands-on web-based activity motivated by the relation between human health and ozone pollution in California. This case study is based on multivariate data collected monthly at 20 locations in California between 1980 and 2006. Several strategies and tools for data interrogation and exploratory data analysis, model fitting and statistical inference on these data are presented. All components of this case study (data, tools, activity) are freely available online at: http://wiki.stat.ucla.edu/socr/index.php/SOCR_MotionCharts_CAOzoneData. Several types of exploratory (motion charts, box-and-whisker plots, spider charts) and quantitative (inference, regression, analysis of variance (ANOVA)) data analyses tools are demonstrated. Two specific human health related questions (temporal and geographic effects of ozone pollution) are discussed as motivational challenges. PMID:24465054

  5. Ozone

    MedlinePlus

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

  6. Houston’s rapid ozone increases: preconditions and geographic origins

    PubMed Central

    Couzo, Evan; Jeffries, Harvey E.; Vizuete, William

    2013-01-01

    Many of Houston’s highest 8-h ozone (O3) peaks are characterised by increases in concentrations of at least 40 ppb in 1 h, or 60 ppb in 2 h. These rapid increases are called non-typical O3 changes (NTOCs). In 2004, the Texas Commission on Environmental Quality (TCEQ) developed a novel emissions control strategy aimed at eliminating NTOCs. The strategy limited routine and short-term emissions of ethene, propene, 1,3-butadiene and butene isomers, collectively called highly reactive volatile organic compounds (HRVOCs), which are released from petrochemical facilities. HRVOCs have been associated with NTOCs through field campaigns and modelling studies. This study analysed wind measurements and O3, formaldehyde (HCHO) and sulfur dioxide (SO2) concentrations from 2000 to 2011 at 25 ground monitors in Houston. NTOCs almost always occurred when monitors were downwind of petrochemical facilities. Rapid O3 increases were associated with low wind speeds; 75 % of NTOCs occurred when the 3-h average wind speed preceding the event was less than 6.5 km h−1. Statistically significant differences in HCHO concentrations were seen between days with and without NTOCs. Early afternoon HCHO concentrations were greater on NTOC days. In the morning before an observed NTOC event, however, there were no significant differences in HCHO concentrations between days with and without NTOCs. Hourly SO2 concentrations also increased rapidly, exhibiting behaviour similar to NTOCs. Oftentimes, the SO2 increases preceded a NTOC. These findings show that, despite the apparent success of targeted HRVOC emission controls, further restrictions may be needed to eliminate the remaining O3 events. PMID:24014080

  7. Economic damages of ozone air pollution to crops using combined air quality and GIS modelling

    NASA Astrophysics Data System (ADS)

    Vlachokostas, Ch.; Nastis, S. A.; Achillas, Ch.; Kalogeropoulos, K.; Karmiris, I.; Moussiopoulos, N.; Chourdakis, E.; Banias, G.; Limperi, N.

    2010-09-01

    This study aims at presenting a combined air quality and GIS modelling methodological approach in order to estimate crop damages from photochemical air pollution, depict their spatial resolution and assess the order of magnitude regarding the corresponding economic damages. The analysis is conducted within the Greater Thessaloniki Area, Greece, a Mediterranean territory which is characterised by high levels of photochemical air pollution and considerable agricultural activity. Ozone concentration fields for 2002 and for specific emission reduction scenarios for the year 2010 were estimated with the Ozone Fine Structure model in the area under consideration. Total economic damage to crops turns out to be significant and estimated to be approximately 43 M€ for the reference year. Production of cotton presents the highest economic loss, which is over 16 M€, followed by table tomato (9 M€), rice (4.2 M€), wheat (4 M€) and oilseed rape (2.8 M€) cultivations. Losses are not spread uniformly among farmers and the major losses occur in areas with valuable ozone-sensitive crops. The results are very useful for highlighting the magnitude of the total economic impacts of photochemical air pollution to the area's agricultural sector and can potentially be used for comparison with studies worldwide. Furthermore, spatial analysis of the economic damage could be of importance for governmental authorities and decision makers since it provides an indicative insight, especially if the economic instruments such as financial incentives or state subsidies to farmers are considered.

  8. Western Pacific Tropospheric Ozone and Potential Vorticity: Implications for Asian Pollution

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.; Newell, Reginald E.; Davis, Douglas D.; Liu, Shaw C.

    1997-01-01

    Tropospheric ozone (03) cross sections measured with lidar from a DC-8 aircraft over the western Pacific correspond closely with potential vorticity (PV). Both are transported from the middle latitude stratosphere, although this is not the only source of 03, and both have sinks in the tropical boundary layer. 03 and PV are good indicators of photochemical and transport process interactions. In summer, some Asian pollution, raised by convection to the upper troposphere, passes southward into the tropics and to the Southern Hemisphere. In winter, subsidence keeps the pollution at low altitudes where it moves over the ocean towards the Inter-Tropical Convergence Zone (ITCZ), with photochemical destruction and secondary pollutant generation occurring en route. Convection raises this modified air to the upper troposphere, where some re may enter the stratosphere. Thus winter Asian pollution may at have a smaller direct influence on the global atmosphere than it would if injected at other longitudes and seasons.

  9. Increased CCL24/Eotaxin-2 with Postnatal Ozone Exposure in Allergen-Sensitized Infant Monkeys Is Not Associated with Recruitment of Eosinophils to Airway Mucosa

    PubMed Central

    Chou, Debbie L.; Gerriets, Joan E.; Schelegle, Edward S.; Hyde, Dallas M.; Miller, Lisa A.

    2011-01-01

    Epidemiology supports a causal link between air pollutant exposure and childhood asthma, but the mechanisms are unknown. We have previously reported that ozone exposure can alter the anatomic distribution of CD25+ lymphocytes in airways of allergen-sensitized infant rhesus monkeys. Here, we hypothesized that ozone may also affect eosinophil trafficking to allergen-sensitized infant airways. To test this hypothesis, we measured blood, lavage, and airway mucosa eosinophils in 3-month old monkeys following cyclical ozone and house dust mite (HDM) aerosol exposures. We also determined if eotaxin family members (CCL11, CCL24, CCL26) are associated with eosinophil location in response to exposures. In lavage, eosinophil numbers increased in animals exposed to ozone and/or HDM. Ozone + HDM animals showed significantly increased CCL24 and CCL26 protein in lavage, but the concentration of CCL11, CCL24, and CCL26 was independent of eosinophil number for all exposure groups. In airway mucosa, eosinophils increased with exposure to HDM alone; comparatively, ozone and ozone + HDM resulted in reduced eosinophils. CCL26 mRNA and immunofluorescence staining increased in airway mucosa of HDM alone animals and correlated with eosinophil volume. In ozone + HDM animal groups, CCL24 mRNA and immunofluorescence increased along with CCR3 mRNA, but did not correlate with airway mucosa eosinophils. Cumulatively, our data indicate that ozone exposure results in a profile of airway eosinophil migration that is distinct from HDM mediated pathways. CCL24 was found to be induced only by combined ozone and HDM exposure, however expression was not associated with the presence of eosinophils within the airway mucosa. PMID:21945493

  10. Improving pollutants removal by microalgae Chlorella PY-ZU1 with 15% CO2 from undiluted anaerobic digestion effluent of food wastes with ozonation pretreatment.

    PubMed

    Cheng, Jun; Ye, Qing; Xu, Jiao; Yang, Zongbo; Zhou, Junhu; Cen, Kefa

    2016-09-01

    In order to purify various pollutants (3108mg COD/L, 2120mg NH3-N/L) in the undiluted anaerobic digestion effluent of food wastes (UADEFW), ozonation pretreatment was employed to improve pollutants removal by microalgae mutant Chlorella PY-ZU1 with 15% CO2. Ozonation pretreatment broke CC bonds and benzene rings of refractory organics such as unsaturated fatty acids and phenols in UADEFW and degraded them into low-molecular-weight organics such as methanoic acid and methanal, but excessive ozone induced the accumulation of toxic by-products. The microalgal growth rate and biomass yield markedly increased to the peaks of 456mg/L/d and 4.3g/L, respectively, when the UADEFW was pretreated with 2mg-O3/mg-C of ozone. The removal efficiencies of NH3-N, TP and COD reached 99%, 99% and 68%, respectively. The lipid and carbohydrate contents of microalgal biomass increased because of the relative lack of nitrogen when microalgae was cultured with 15% CO2 to purify the UADEFW with ozonation pretreatment.

  11. Improving pollutants removal by microalgae Chlorella PY-ZU1 with 15% CO2 from undiluted anaerobic digestion effluent of food wastes with ozonation pretreatment.

    PubMed

    Cheng, Jun; Ye, Qing; Xu, Jiao; Yang, Zongbo; Zhou, Junhu; Cen, Kefa

    2016-09-01

    In order to purify various pollutants (3108mg COD/L, 2120mg NH3-N/L) in the undiluted anaerobic digestion effluent of food wastes (UADEFW), ozonation pretreatment was employed to improve pollutants removal by microalgae mutant Chlorella PY-ZU1 with 15% CO2. Ozonation pretreatment broke CC bonds and benzene rings of refractory organics such as unsaturated fatty acids and phenols in UADEFW and degraded them into low-molecular-weight organics such as methanoic acid and methanal, but excessive ozone induced the accumulation of toxic by-products. The microalgal growth rate and biomass yield markedly increased to the peaks of 456mg/L/d and 4.3g/L, respectively, when the UADEFW was pretreated with 2mg-O3/mg-C of ozone. The removal efficiencies of NH3-N, TP and COD reached 99%, 99% and 68%, respectively. The lipid and carbohydrate contents of microalgal biomass increased because of the relative lack of nitrogen when microalgae was cultured with 15% CO2 to purify the UADEFW with ozonation pretreatment. PMID:27243605

  12. The impact of observing characteristics on the ability to predict ozone under varying polluted photochemical regimes

    NASA Astrophysics Data System (ADS)

    Hamer, P. D.; Bowman, K. W.; Henze, D. K.; Attié, J.-L.; Marécal, V.

    2015-09-01

    We conduct analyses to assess how characteristics of observations of ozone and its precursors affect air quality forecasting and research. To carry out this investigation, we use a photochemical box model and its adjoint integrated with a Lagrangian 4D-variational data assimilation system. Using this framework in conjunction with pseudo-observations, we perform an ozone precursor source inversion and estimate surface emissions. We then assess the resulting improvement in ozone air quality prediction. We use an analytical model to conduct uncertainty analyses. Using this analytical tool, we address some key questions regarding how the characteristics of observations affect ozone precursor emission inversion and in turn ozone prediction. These questions include what the effect is of choosing which species to observe, of varying amounts of observation noise, of changing the observing frequency and the observation time during the diurnal cycle, and of how these different scenarios interact with different photochemical regimes. In our investigation we use three observed species scenarios: CO and NO2; ozone, CO, and NO2; and HCHO, CO and NO2. The photochemical model was set up to simulate a range of summertime polluted environments spanning NOx-(NO and NO2)-limited to volatile organic compound (VOC)-limited conditions. We find that as the photochemical regime changes, here is a variation in the relative importance of trace gas observations to be able to constrain emission estimates and to improve the subsequent ozone forecasts. For example, adding ozone observations to an NO2 and CO observing system is found to decrease ozone prediction error under NOx- and VOC-limited regimes, and complementing the NO2 and CO system with HCHO observations would improve ozone prediction in the transitional regime and under VOC-limited conditions. We found that scenarios observing ozone and HCHO with a relative observing noise of lower than 33 % were able to achieve ozone prediction

  13. Intercontinental and Regional Modeling of Multiple Pollutants (Particulate Matter, Ozone, and Mercury) over the Pacific Regions

    NASA Astrophysics Data System (ADS)

    Jang, C. C.; Fu, J. S.; Wang, B.; Streets, D. G.; Doll, D.; Woo, J.; Hanna, A.; Vukovich, J.; Xiu, A.; Adelman, Z.

    2004-12-01

    There is increasing evidence that air pollutants originating from regions outside of North America such as Asia could impact U.S. domestic air quality. At the same time, the U.S. is both an importer and exporter of air pollutants. A pioneer modeling project, the Intercontinental Transport and Climatic Effects of Air Pollutants (ICAP) project, has been undertaken at U.S EPA to help understand and assess these impacts associated with the intercontinental transport of air pollutants, including particulate matter (PM), ozone (O3), and mercury (Hg). The on-going modeling efforts include a series of modeling (108-km grid resolution) and emissions related activities over the pacific regions, including a 2001 Base year simulation, 2030 scenarios (IPCC's A1B and B2 scenarios), and several sensitivity studies (e.g., removal of man-made Asian emissions and North America emissions, etc.). The trans-Atlantic modeling effort has also been under way. The key modeling tool used in this project is the Models?3/Community Multi-scale Air Quality (CMAQ) modeling system developed at EPA. In addition, a related modeling effort has been undertaken to conduct model simulations over the East Asia (36-km grid) and an East China region (12-km grid). An expansion of this China modeling effort to urban fine-grid modeling (4-km grid) in Beijing and Shanghai has also been under way. The trans-Pacific modeling results revealed that PM 2.5 and O3 can be transported across the Pacific Ocean over a time period of 5 to 10 days before reaching North America and the U.S. A sensitivity study by removing the Asian man-made emissions showed that the impact of Asian man-made emissions on North America appeared to be persistent through the entire year, although exhibiting seasonal variations. The spring (April) had higher impact for PM 2.5, up to 2-2.5 ug/m3 (monthly average) in the western U.S. and up to 1-1.5 ug/m3 in the eastern U.S., while the summer (July) and spring (April) has comparable impacts for

  14. Ultraviolet B radiation was increased at ground level in scotland during a period of ozone depletion.

    PubMed

    Moseley, H; Mackie, R M

    1997-07-01

    The potentially harmful effects associated with stratospheric ozone depletion are widely acknowledged. As the ozone layer principally absorbs ultraviolet (UV) radiation of wavelengths below 290 nm, reductions in stratospheric ozone levels are likely to result in increased UVB at the earth's surface, with the risk of increased incidence of skin cancer. Measuring the sun's spectrum at ground level requires sophisticated and reliable spectral instruments. Results are reported for this for the first time in the U.K. using spectral instruments, showing a significant increase in short wavelength UV radiation at a time of depleted stratospheric ozone. If this trend increases, future ozone depletion could contribute to known risks for cutaneous malignancies of all types.

  15. Alteration of extracellular enzymes in pinto bean leaves upon exposure to air pollutants, ozone and sulfur dioxide

    SciTech Connect

    Peters, J.L.; Castillo, F.J.; Heath, R.L. )

    1989-01-01

    Diamine oxidase and peroxidase, associated with the wall in pinto bean (Phaseolus vulgaris L. var Pinto) leaves, can be washed out by vacuum infiltration and assayed without grinding the leaf. The diamine oxidase activity is inhibited in vivo by exposure of the plants to ozone (dose of 0.6 microliters per liter {times} hour), whereas the peroxidase activity associated with the wall space is stimulated. This dose does not cause obvious necrosis or chlorosis of the leaf. These alterations are greater when the dose of ozone exposure is given as a triangular pulse (a slow rise to a peak of 0.24 microliters per liter followed by a slow fall) compared to that given as a constant square wave pulse of 0.15 microliters per liter for the same 4 hour period. Exposure of the plants to sulfur dioxide (at a concentration of 0.4 microliters per liter for 4 hours) does not result in any change in the diamine oxidase or peroxidase activities, yet the total sulfhydryl content of the leaf is increased, demonstrating the entry of sulfur dioxide. These two pollutants, with different chemical reactivities, affect the activities of the extracellular enzymes in different manners. In the case of ozone exposure, the inhibition of extracellular diamine oxidase could profoundly alter the movements of polyamines from cell to cell.

  16. Chemical Diversity and Defence Metabolism: How Plants Cope with Pathogens and Ozone Pollution

    PubMed Central

    Iriti, Marcello; Faoro, Franco

    2009-01-01

    Chemical defences represent a main trait of the plant innate immune system. Besides regulating the relationship between plants and their ecosystems, phytochemicals are involved both in resistance against pathogens and in tolerance towards abiotic stresses, such as atmospheric pollution. Plant defence metabolites arise from the main secondary metabolic routes, the phenylpropanoid, the isoprenoid and the alkaloid pathways. In plants, antibiotic compounds can be both preformed (phytoanticipins) and inducible (phytoalexins), the former including saponins, cyanogenic glycosides and glucosinolates. Chronic exposure to tropospheric ozone (O3) stimulates the carbon fluxes from the primary to the secondary metabolic pathways to a great extent, inducing a shift of the available resources in favour of the synthesis of secondary products. In some cases, the plant defence responses against pathogens and environmental pollutants may overlap, leading to the unspecific synthesis of similar molecules, such as phenylpropanoids. Exposure to ozone can also modify the pattern of biogenic volatile organic compounds (BVOC), emitted from plant in response to herbivore feeding, thus altering the tritrophic interaction among plant, phytophagy and their natural enemies. Finally, the synthesis of ethylene and polyamines can be regulated by ozone at level of S-adenosylmethionine (SAM), the biosynthetic precursor of both classes of hormones, which can, therefore, mutually inhibit their own biosynthesis with consequence on plant phenotype. PMID:20111684

  17. Chemical diversity and defence metabolism: how plants cope with pathogens and ozone pollution.

    PubMed

    Iriti, Marcello; Faoro, Franco

    2009-07-30

    Chemical defences represent a main trait of the plant innate immune system. Besides regulating the relationship between plants and their ecosystems, phytochemicals are involved both in resistance against pathogens and in tolerance towards abiotic stresses, such as atmospheric pollution. Plant defence metabolites arise from the main secondary metabolic routes, the phenylpropanoid, the isoprenoid and the alkaloid pathways. In plants, antibiotic compounds can be both preformed (phytoanticipins) and inducible (phytoalexins), the former including saponins, cyanogenic glycosides and glucosinolates. Chronic exposure to tropospheric ozone (O(3)) stimulates the carbon fluxes from the primary to the secondary metabolic pathways to a great extent, inducing a shift of the available resources in favour of the synthesis of secondary products. In some cases, the plant defence responses against pathogens and environmental pollutants may overlap, leading to the unspecific synthesis of similar molecules, such as phenylpropanoids. Exposure to ozone can also modify the pattern of biogenic volatile organic compounds (BVOC), emitted from plant in response to herbivore feeding, thus altering the tritrophic interaction among plant, phytophagy and their natural enemies. Finally, the synthesis of ethylene and polyamines can be regulated by ozone at level of S-adenosylmethionine (SAM), the biosynthetic precursor of both classes of hormones, which can, therefore, mutually inhibit their own biosynthesis with consequence on plant phenotype.

  18. Indoor Secondary Pollutants from Household Product Emissions inthe Presence of Ozone: A Bench-Scale Chamber Study

    SciTech Connect

    Destaillats, Hugo; Lunden, Melissa M.; Singer, Brett C.; Coleman,Beverly K.; Hodgson, Alfred T.; Weschler, Charles J.; Nazaroff, William W.

    2005-10-01

    Ozone-driven chemistry is a major source of indoor secondary pollutants of health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields under most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of ultrafine particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 x 10{sup 5} molecules cm{sup -3} were measured. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1-25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate test, we exposed the dry residue of two products to ozone in the chamber and observed the formation of gas-phase and particle-phase secondary oxidation products.

  19. The increase of Southern Ocean winds and SAM: is it caused by the ozone hole or by increased greenhouse gases?

    NASA Astrophysics Data System (ADS)

    Roscoe, H. K.

    2010-12-01

    The amplitude of the Southern Annular Mode of variability in sea level pressure has increased significantly since station records began in the late 1950s. As expected, this has led to an increase in surface winds over the Southern Ocean in meteorological analyses. Roscoe & Haigh (2007), using data to 2006, showed that the increase in SAM correlated at high significance with both the ozone hole and the increase in greenhouse gases, but the correlation with the ozone hole was more significant. However, it was difficult to quantify the meaning of this greater significance because of the then similarity between the trends in greenhouse gases and the ozone hole - the esoteric statistical concepts associated with the Akaike Information Criterion had to be used. Now the trends have diverged significantly, so the update presented here allows us to quantify the greater degree of significance of the ozone hole, using the more familiar statistical method of Student’s t-test.

  20. Convective Lofting Links Indian Ocean Air Pollution to Paradoxical South Atlantic Ozone Maxima

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert B.; Guan, Hong; Thompson, Anne M.; Witte, Jacquelyn C.

    2003-01-01

    We describe a broad resolution of the "Atlantic Paradox" concerning the seasonal and geographic distribution of tropical tropospheric ozone. We describe periods of significant maximum tropospheric O3 for Jan.-April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO)O3 maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.- March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 30 or 60 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

  1. Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima

    NASA Technical Reports Server (NTRS)

    Chatfield, R. B.; Guan, H.; Thompson, A. M.; Witte, J. C.

    2005-01-01

    We describe a broad resolution of the Atlantic Parado concerning the seasonal and geographic distribution, of tropical tropospheric ozone. We highlight periods of significant maximum tropospheric O3 for Jan.- April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO) maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, possible stratospheric input, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.-March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 20-50 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

  2. Estradiol prevents ozone-induced increases in brain lipid peroxidation and impaired social recognition memory in female rats.

    PubMed

    Guevara-Guzmán, R; Arriaga, V; Kendrick, K M; Bernal, C; Vega, X; Mercado-Gómez, O F; Rivas-Arancibia, S

    2009-03-31

    There is increasing concern about the neurodegenerative and behavioral consequences of ozone pollution in industrialized urban centers throughout the world and that women may be more susceptible to brain neurodegenerative disorders. In the present study we have investigated the effects of chronic (30 or 60 days) exposure to ozone on olfactory perception and memory and on levels of lipid peroxidation, alpha and beta estrogen receptors and dopamine beta-hydroxylase in the olfactory bulb in ovariectomized female rats. The ability of 17beta-estradiol to prevent these effects was then assessed. Results showed that ozone exposure for 30 or 60 days impaired formation/retention of a selective olfactory recognition memory 120 min after exposure to a juvenile stimulus animal with the effect at 60 days being significantly greater than at 30 days. They also showed impaired speed in locating a buried chocolate reward after 60 days of ozone exposure indicating some loss of olfactory perception. These functional impairments could all be prevented by coincident estradiol treatment. In the olfactory bulb, levels of lipid peroxidation were increased at both 30- and 60-day time-points and numbers of cells with immunohistochemical staining for alpha and beta estrogen receptors, and dopamine beta-hydroxylase were reduced as were alpha and beta estrogen receptor protein levels. These effects were prevented by estradiol treatment. Oxidative stress damage caused by chronic exposure to ozone does therefore impair olfactory perception and social recognition memory and may do so by reducing noradrenergic and estrogen receptor activity in the olfactory bulb. That these effects can be prevented by estradiol treatment suggests increased susceptibility to neurodegenerative disorders in aging women may be contributed to by reduced estrogen levels post-menopause.

  3. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-04-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

  4. [Modeling Study of A Typical Summer Ozone Pollution Event over Yangtze River Delta].

    PubMed

    Zhang, Liang; Zhu, Bin; Gao, Jin-hui; Kang, Han-qing; Yang, Peng; Wang, Hong-lei; Li, Yue-e; Shao, Ping

    2015-11-01

    WRF/Chem model was used to analyze the temporal and spatial distribution characteristics and physical and chemical mechanism of a typical summer ozone pollution event over Yangtze River Delta (YRD). The result showed that the model was capable of reproducing the temporal and spatial distribution and evolution characteristics of the typical summer ozone pollution event over YRD. The YRD region was mainly affected by the subtropical high-pressure control, and the weather conditions of sunshine, high temperature and small wind were favorable for the formation of photochemical pollution on August 10-18, 2013. The results of simulation showed that the spatial and temporal distribution of O3 was obviously affected by the meteorological fields, geographic location, regional transport and chemical formation over YRD. The sensitivity experiment showed that the O3 concentration affected by maritime airstream was low in Shanghai, but the impact of Shanghai emissions on the spatial and temporal distribution of O3 concentration over YRD was significant; The main contribution of the high concentration of O3 in Nanjing surface was chemical generation ( alkene and aromatic) and the vertical transport from high-altitude O3, whereas the main contribution of the high concentration of O3 in Hangzhou and Suzhou was physics process. The influence of the 15:00 peak concentration of O3 over YRD was very obvious when O3 precursor was reduced at the maximum O3 formation rate (11-13 h).

  5. Who is more affected by ozone pollution? A systematic review and meta-analysis.

    PubMed

    Bell, Michelle L; Zanobetti, Antonella; Dominici, Francesca

    2014-07-01

    Ozone is associated with adverse health; however, less is known about vulnerable/sensitive populations, which we refer to as sensitive populations. We systematically reviewed epidemiologic evidence (1988-2013) regarding sensitivity to mortality or hospital admission from short-term ozone exposure. We performed meta-analysis for overall associations by age and sex; assessed publication bias; and qualitatively assessed sensitivity to socioeconomic indicators, race/ethnicity, and air conditioning. The search identified 2,091 unique papers, with 167 meeting inclusion criteria (73 on mortality and 96 on hospitalizations and emergency department visits, including 2 examining both mortality and hospitalizations). The strongest evidence for ozone sensitivity was for age. Per 10-parts per billion increase in daily 8-hour ozone concentration, mortality risk for younger persons, at 0.60% (95% confidence interval (CI): 0.40, 0.80), was statistically lower than that for older persons, at 1.27% (95% CI: 0.76, 1.78). Findings adjusted for publication bias were similar. Limited/suggestive evidence was found for higher associations among women; mortality risks were 0.39% (95% CI: -0.22, 1.00) higher than those for men. We identified strong evidence for higher associations with unemployment or lower occupational status and weak evidence of sensitivity for racial/ethnic minorities and persons with low education, in poverty, or without central air conditioning. Findings show that some populations, especially the elderly, are particularly sensitive to short-term ozone exposure. PMID:24872350

  6. Background ozone over the United States in summer: Origin, trend, and contribution to pollution episodes

    NASA Astrophysics Data System (ADS)

    Fiore, Arlene M.; Jacob, Daniel J.; Bey, Isabelle; Yantosca, Robert M.; Field, Brendan D.; Fusco, Andrew C.; Wilkinson, James G.

    2002-08-01

    Observations indicate that ozone (O3) concentrations in surface air over the United States in summer contain a 20-45 ppbv background contribution, presumably reflecting transport from outside the North American boundary layer. We use a three-dimensional global model of tropospheric chemistry driven by assimilated meteorological observations to investigate the origin of this background and to quantify its contribution to total surface O3 on both average and highly polluted summer days. The model simulation is evaluated with a suite of surface and aircraft observations over the United States from the summer of 1995. The model reproduces the principal features in the observed distributions of O3 and its precursors, including frequency distributions of O3 concentrations and the development of regional high-O3 episodes in the eastern United States. Comparison of simulations with 1995 versus 1980 global fossil fuel emissions indicates that the model captures the previously observed decrease in the high end of the O3 probability distribution in surface air over the United States (reflecting reduction of domestic hydrocarbon emissions) and the increase in the low end (reflecting, at least in the model, rising Asian emissions). In the model, background O3 produced outside of the North American boundary layer contributes an average 25-35 ppbv to afternoon O3 concentrations in surface air in the western United States. and 15-30 ppbv in the eastern United States during the summer of 1995. This background generally decays to below 15 ppbv during the stagnation conditions conducive to exceedances of the 8-hour 0.08 ppmv (80 ppbv) National Ambient Air Quality Standard (NAAQS) for O3. A high background contribution of 25-40 ppbv is found during 9% of these exceedances, reflecting convective mixing of free tropospheric O3 from aloft, followed by rapid production within the U.S. boundary layer. Anthropogenic emissions in Asia and Europe are found to increase afternoon O3

  7. Anthropogenic emissions in Nigeria and implications for atmospheric ozone pollution: A view from space

    NASA Astrophysics Data System (ADS)

    Marais, E. A.; Jacob, D. J.; Wecht, K.; Lerot, C.; Zhang, L.; Yu, K.; Kurosu, T. P.; Chance, K.; Sauvage, B.

    2014-12-01

    Nigeria has a high population density and large fossil fuel resources but very poorly managed energy infrastructure. Satellite observations of formaldehyde (HCHO) and glyoxal (CHOCHO) reveal very large sources of anthropogenic nonmethane volatile organic compounds (NMVOCs) from the Lagos megacity and oil/gas operations in the Niger Delta. This is supported by aircraft observations over Lagos and satellite observations of methane in the Niger Delta. Satellite observations of carbon monoxide (CO) and nitrogen dioxide (NO2) show large seasonal emissions from open fires in December-February (DJF). Ventilation of central Nigeria is severely restricted at that time of year, leading to very poor ozone air quality as observed from aircraft (MOZAIC) and satellite (TES). Simulations with the GEOS-Chem chemical transport model (CTM) suggest that maximum daily 8-h average (MDA8) ozone exceeds 70 ppbv over the region on a seasonal mean basis, with significant contributions from both open fires (15-20 ppbv) and fuel/industrial emissions (7-9 ppbv). The already severe ozone pollution in Nigeria could worsen in the future as a result of demographic and economic growth, although this would be offset by a decrease in open fires.

  8. Generation of sub-micron particles and secondary pollutants from building materials by ozone reaction

    NASA Astrophysics Data System (ADS)

    Aoki, Taisuke; Tanabe, Shin-ichi

    This study reports results from two different experiments examining reactions between ozone and common building materials that can lead to the formation of secondary products and particulate-phase materials. Monitored species include sub-micron particles and volatile organic compounds (VOCs). In the first set of experiments, various building materials were placed in a 20 L stainless-steel chamber and exposed to ozone. The materials included expanded polystyrene, a natural rubber adhesive, cedar board, Japanese Cyprus board and silver fir board, as well as d-limonene, which is a known constituent of certain woods and cleaning products. The combination of ozone and either d-limonene, cedar board or cypress board produced sub-micron particles, with most of the increase occurring in the size range of 0.01- 0.5μm diameter. This was not observed for the other materials. In the case of cedar board, the consequence of ozone exposure over an extended time interval was monitored. As the exposure time elapsed, the concentration of sub-micron particles moderately decreased. In the second set of experiments, unwaxed or waxed plastic tiles were placed in the 20 L chamber and exposed to ozone. Sub-micron particles and organic compounds were measured during the course of the experiments. In the case of the waxed tile, the number of 0.01- 1.0μm size particles grew about 50×108particlesm-3; particle growth was significantly less for the un-waxed tile. For both the waxed and un-waxed tiles, the emission rates of heptane, nonane, nonanal, and decanal increased after ozone was added to the supply air. (However, it is not clear if some or all of this production was due to ozone reacting with the sorbent used for sampling or with compounds captured by the sorbent.) This study provides further evidence that ozone-initiated reactions with building materials can be a significant source of both sub-micron particles and secondary organic compounds in indoor environments.

  9. Web-based tools for modelling and analysis of multivariate data: California ozone pollution activity

    NASA Astrophysics Data System (ADS)

    Dinov, Ivo D.; Christou, Nicolas

    2011-09-01

    This article presents a hands-on web-based activity motivated by the relation between human health and ozone pollution in California. This case study is based on multivariate data collected monthly at 20 locations in California between 1980 and 2006. Several strategies and tools for data interrogation and exploratory data analysis, model fitting and statistical inference on these data are presented. All components of this case study (data, tools, activity) are freely available online at: http://wiki.stat.ucla.edu/socr/index.php/SOCR_MotionCharts_CAOzoneData. Several types of exploratory (motion charts, box-and-whisker plots, spider charts) and quantitative (inference, regression, analysis of variance (ANOVA)) data analyses tools are demonstrated. Two specific human health related questions (temporal and geographic effects of ozone pollution) are discussed as motivational challenges.

  10. The potential impact on atmospheric ozone and temperature of increasing trace gas concentrations

    NASA Technical Reports Server (NTRS)

    Brasseur, G.; Derudder, A.

    1987-01-01

    The response of the atmosphere to emissions of chlorofluorocarbons (CFCs) and other chlorocarbons, and to increasing concentrations of other radiatively active trace gases such as CO2, CH4, and N2O is calculated by a coupled chemical-radiative transport one-dimensional model. It is shown that significant reductions in the ozone concentration and in the temperature are expected in the upper stratosphere as a result of increasing concentrations of active chlorine produced by photodecomposition of the CFCs. The ozone content is expected to increase in the troposphere, as a consequence of increasing concentrations of methane and nitrogen oxides. Due to enhanced greenhouse effects, the Earth's surface should warm up by several degrees. The amplitude and even the sign of future changes in the ozone column are difficult to predict as they are strongly scenario-dependent. An early detection system to prevent noticeable ozone changes as a result of increasing concentrations of source gases should thus be based on a continuous monitoring of the ozone amount in the upper stratosphere rather than on measurements of the ozone column only. Measurements of NOx, Clx, and HOx are also required for unambiguous trend detection and interpretation.

  11. Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

    SciTech Connect

    Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie; Brunner, Gregory; Zhang, Jianshun; Fisk, William J.

    2011-05-01

    , rather than ozonolysis, is the main formaldehyde source in those filters. Emission rates of formaldehyde and acetaldehyde were not found to be large enough to substantially increase indoor concentrations in typical building scenarios. Nevertheless, ozone reactions on HVAC filters cannot be ignored as a source of low levels of indoor irritants.

  12. Ozone exposure of human tracheal epithelial cells inactivates cyclooxygenase and increases 15-HETE production.

    PubMed

    Alpert, S E; Walenga, R W

    1995-12-01

    We assessed the immediate and prolonged effects of ozone on arachidonic acid (AA) metabolism by primary cultured human tracheal epithelial (TE) cells. TE monolayers were exposed at a gas-fluid interface to air or 0.1, 0.25, or 0.5 ppm ozone (15 min air, then 45 min air/ozone), and serially collected effluents were analyzed by thin-layer chromatography (TLC) and/or high-performance liquid chromatography. Release of prostaglandin E2 (PGE2) and AA, but not 15-hydroxyeicosatetraenoic acid (15-HETE) or its metabolites, was detected from cultures prelabeled with [14C]AA. PGE2 production, measured by immunoassay, was nearly constant during air exposure. In contrast, PGE2 increased two- to threefold during the first 15-min exposure to all concentrations of ozone, but then progressively declined to 78 +/- 17, 57 +/- 12 (P < or = 0.05), and 45 +/- 15% (P < or = 0.05) of air controls after exposure to 0.1, 0.25, and 0.5 ppm ozone. Ozone did not induce a new spectrum of AA metabolites; only PGE2, lesser amounts of PGF2 alpha, and 15-HETE were present in media and cell extracts of air- or ozone-exposed cultures provided with 30 microM exogenous AA. However, cyclooxygenase (CO) activity (PGE2 produced from 30 microM AA) decreased to 82 +/- 9, 53 +/- 8 (P < or = 0.05), and 28 +/- 6% (P < or = 0.05) vs. controls after 0.1, 0.25, and 0.5 ppm ozone, whereas 15-HETE production was unimpaired. When cells exposed to 0.5 ppm ozone were maintained for up to 6 h in 5% CO2-air, spontaneous PGE2 production remained decreased and recovery of CO activity was extremely slow. TLC analysis of lipid extracts from [14C]AA-labeled cells revealed a nearly twofold increase in free intracellular 15-HETE, and hydrolysis of phospholipids demonstrated increased esterified 15-HETE. Exposure of human TE cells to ozone leads to a transient increase followed by prolonged decrease in PGE2 production and increased intracellular retention of 15-HETE. Loss of the bronchodilator and anti-inflammatory properties

  13. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific.

    PubMed

    Nath, Debashis; Chen, Wen; Graf, Hans-F; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-02-12

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10-25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals.

  14. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific

    NASA Astrophysics Data System (ADS)

    Nath, Debashis; Chen, Wen; Graf, Hans-F.; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-02-01

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10-25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals.

  15. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific

    PubMed Central

    Nath, Debashis; Chen, Wen; Graf, Hans-F.; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-01-01

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10–25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals. PMID:26868836

  16. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific.

    PubMed

    Nath, Debashis; Chen, Wen; Graf, Hans-F; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-01-01

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10-25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals. PMID:26868836

  17. Air pollution and watershed research in the central Sierra Nevada of California: nitrogen and ozone.

    PubMed

    Hunsaker, Carolyn; Bytnerowicz, Andrzej; Auman, Jessica; Cisneros, Ricardo

    2007-01-01

    Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3) and nitrogenous (N) air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100-2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes. PMID:17450299

  18. Air pollution and watershed research in the central Sierra Nevada of California: nitrogen and ozone.

    PubMed

    Hunsaker, Carolyn; Bytnerowicz, Andrzej; Auman, Jessica; Cisneros, Ricardo

    2007-01-01

    Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3) and nitrogenous (N) air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100-2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes.

  19. Catalytic ozonation of organic pollutants from bio-treated dyeing and finishing wastewater using recycled waste iron shavings as a catalyst: Removal and pathways.

    PubMed

    Wu, Jin; Ma, Luming; Chen, Yunlu; Cheng, Yunqin; Liu, Yan; Zha, Xiaosong

    2016-04-01

    Catalytic ozonation of organic pollutants from actual bio-treated dyeing and finishing wastewater (BDFW) with iron shavings was investigated. Catalytic ozonation effectively removed organic pollutants at initial pH values of 7.18-7.52, and the chemical oxygen demand (COD) level decreased from 142 to 70 mg·L(-1) with a discharge limitation of 80 mg·L(-1). A total of 100% and 42% of the proteins and polysaccharides, respectively, were removed with a decrease in their contribution to the soluble COD from 76% to 41%. Among the 218 organic species detected by liquid chromatography-mass spectrometry, 58, 77, 79 and 4 species were completely removed, partially removed, increased and newly generated, respectively. Species including textile auxiliaries and dye intermediates were detected by gas chromatography-mass spectrometry. The inhibitory effect decreased from 51% to 33%, suggesting a reduction in the acute toxicity. The enhanced effect was due to hydroxyl radical (OH) oxidation, co-precipitation and oxidation by other oxidants. The proteins were removed by OH oxidation (6%), by direct ozonation, co-precipitation and oxidation by other oxidants (94%). The corresponding values for polysaccharides were 21% and 21%, respectively. In addition, the iron shavings behaved well in successive runs. These results indicated that the process was favorable for engineering applications for removal of organic pollutants from BDFW.

  20. The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030

    NASA Astrophysics Data System (ADS)

    Dentener, F.; Stevenson, D.; Cofala, J.; Mechler, R.; Amann, M.; Bergamaschi, P.; Raes, F.; Derwent, R.

    2005-07-01

    To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH4), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx) up to the year 2030 and implemented them in two global Chemistry Transport Models. The "Current Legislation" (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a "Maximum technically Feasible Reduction" (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NOx, NMVOC and CO than was suggested by the widely used and more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000), which made Business-as-Usual assumptions regarding emission control technology. With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH4, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce broadly the observed trends in CO, and CH4 concentrations from 1990 to 2002.

    For the "current legislation" case, both models indicate an increase of the

  1. Ozone, Tropospheric

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1995-01-01

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

  2. Increased lung resistance after diesel particulate and ozone co-exposure not associated with enhanced lung inflammation in allergic mice*

    EPA Science Inventory

    Exposure to diesel exhaust particle matter (DEP) exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (03) . Since levels of both pollutants in ambient air tend to be simultaneously elevated, we investigated the possi...

  3. Characterizing ozone pollution in a petrochemical industrial area in Beijing, China: a case study using a chemical reaction model.

    PubMed

    Wei, Wei; Lv, Zhaofeng; Cheng, Shuiyuan; Wang, Lili; Ji, Dongsheng; Zhou, Ying; Han, Lihui; Wang, Litao

    2015-06-01

    This study selected a petrochemical industrial complex in Beijing, China, to understand the characteristics of surface ozone (O3) in this industrial area through the on-site measurement campaign during the July-August of 2010 and 2011, and to reveal the response of local O3 to its precursors' emissions through the NCAR-Master Mechanism model (NCAR-MM) simulation. Measurement results showed that the O3 concentration in this industrial area was significantly higher, with the mean daily average of 124.6 μg/m(3) and mean daily maximum of 236.8 μg/m(3), which are, respectively, 90.9 and 50.6 % higher than those in Beijing urban area. Moreover, the diurnal O3 peak generally started up early in 11:00-12:00 and usually remained for 5-6 h, greatly different with the normal diurnal pattern of urban O3. Then, we used NCAR-MM to simulate the average diurnal variation of photochemical O3 in sunny days of August 2010 in both industrial and urban areas. A good agreement in O3 diurnal variation pattern and in O3 relative level was obtained for both areas. For example of O3 daily maximum, the calculated value in the industrial area was about 51 % higher than in the urban area, while measured value in the industrial area was approximately 60 % higher than in the urban area. Finally, the sensitivity analysis of photochemical O3 to its precursors was conducted based on a set of VOCs/NOx emissions cases. Simulation results implied that in the industrial area, the response of O3 to VOCs was negative and to NOx was positive under the current conditions, with the sensitivity coefficients of -0.16~-0.43 and +0.04~+0.06, respectively. By contrast, the urban area was within the VOCs-limitation regime, where ozone enhancement in response to increasing VOCs emissions and to decreasing NOx emission. So, we think that the VOCs emissions control for this petrochemical industrial complex will increase the potential risk of local ozone pollution aggravation, but will be helpful to inhibit the

  4. Characterizing ozone pollution in a petrochemical industrial area in Beijing, China: a case study using a chemical reaction model.

    PubMed

    Wei, Wei; Lv, Zhaofeng; Cheng, Shuiyuan; Wang, Lili; Ji, Dongsheng; Zhou, Ying; Han, Lihui; Wang, Litao

    2015-06-01

    This study selected a petrochemical industrial complex in Beijing, China, to understand the characteristics of surface ozone (O3) in this industrial area through the on-site measurement campaign during the July-August of 2010 and 2011, and to reveal the response of local O3 to its precursors' emissions through the NCAR-Master Mechanism model (NCAR-MM) simulation. Measurement results showed that the O3 concentration in this industrial area was significantly higher, with the mean daily average of 124.6 μg/m(3) and mean daily maximum of 236.8 μg/m(3), which are, respectively, 90.9 and 50.6 % higher than those in Beijing urban area. Moreover, the diurnal O3 peak generally started up early in 11:00-12:00 and usually remained for 5-6 h, greatly different with the normal diurnal pattern of urban O3. Then, we used NCAR-MM to simulate the average diurnal variation of photochemical O3 in sunny days of August 2010 in both industrial and urban areas. A good agreement in O3 diurnal variation pattern and in O3 relative level was obtained for both areas. For example of O3 daily maximum, the calculated value in the industrial area was about 51 % higher than in the urban area, while measured value in the industrial area was approximately 60 % higher than in the urban area. Finally, the sensitivity analysis of photochemical O3 to its precursors was conducted based on a set of VOCs/NOx emissions cases. Simulation results implied that in the industrial area, the response of O3 to VOCs was negative and to NOx was positive under the current conditions, with the sensitivity coefficients of -0.16~-0.43 and +0.04~+0.06, respectively. By contrast, the urban area was within the VOCs-limitation regime, where ozone enhancement in response to increasing VOCs emissions and to decreasing NOx emission. So, we think that the VOCs emissions control for this petrochemical industrial complex will increase the potential risk of local ozone pollution aggravation, but will be helpful to inhibit the

  5. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  6. Pollution prevention and stratospheric ozone layer protection through innovative procurement methods: The chiller basic ordering agreement

    SciTech Connect

    Snyder, R.E.; Coyle, J.E.; Guice, J.R. Jr.; Kale, S.H.

    1997-12-31

    The Department of Energy (DOE) and the General Services Administration (GSA) have devised an affirmative procurement vehicle to encourage replacement of chillers using chlorofluorocarbon (CFC) refrigerants harmful to the Earth`s stratospheric ozone layer. Procurement selections are based on lowest life cycle cost. Linked with a DOE-developed Equipment Specification for 100 to 2,000 ton chillers that is crafted broadly enough to address about 90% of the Federal water-cooled chiller procurements, the Basic Ordering Agreement (BOA) process significantly reduces redundant design, procurement, and other costs associated with Federal purchasing of chillers through the cutting of red tape associated with buying industrial equipment. While serving to minimize the release of ozone-depleting substances (about six million tons of CFCs) to the environment, the installation of more energy-efficient chillers also promotes environmental stewardship in that reduced energy consumption translates into reduced emissions of noxious gases from the generation of electricity. Use of the BOA to purchase chillers consistent with Federal energy efficiency standards will contribute to reductions of almost a million tons annually of nitrous oxides, sulfur dioxide, and other pollutants from power plant emissions. Reduced electricity consumption of approximately 1.5 billion kilowatt hours per year by switching to more efficient chillers equates to an annual monetary savings of $75 million.

  7. Ozone

    SciTech Connect

    Not Available

    1988-06-01

    The author discusses the debate over whether concern about a hole in the ozone layer in Antarctic is real or science fiction. There is a growing consensus that efforts must be taken to protect the ozone layer. The issue now is not whether chlorofluorocarbons (CFCs) should be controlled and regulated but how much and how soon. The United States has urged that the production of dangerous CFCs, and any other chemicals that affect the ozone layer, be restricted immediately to current levels and that their use be reduced 95 percent over the next decade. The American position was too strong for many European nations and the Japanese. Negotiations at an international conference on the matter broke down. The breakdown is due in part to a more acute concern for environmental matters in the United States than exists in many countries. Meanwhile CFCs are linked to another environmental problem that equally threatens the world - the Greenhouse Effect. The earth is in a natural warming period, but man could be causing it to become even warmer. The Greenhouse Effect could have a catastrophic impact on mankind, although nothing has been proven yet.

  8. Effect of different molecular weight organic components on the increase of microbial growth potential of secondary effluent by ozonation.

    PubMed

    Zhao, Xin; Hu, Hong-Ying; Yu, Tong; Su, Chang; Jiang, Haochi; Liu, Shuming

    2014-11-01

    Ozonation has been widely applied in advanced wastewater treatment. In this study, the effect of ozonation on assimilable organic carbon (AOC) levels in secondary effluents was investigated, and AOC variation of different molecular weight (MW) organic components was analyzed. Although the removal efficiencies were 47%-76% and 94%-100% for UV254 and color at ozone dosage of 10mg/L, dissolved organic carbon (DOC) in secondary effluents was hardly removed by ozonation. The AOC levels increased by 70%-780% at an ozone dosage range of 1-10mg/L. AOC increased significantly in the instantaneous ozone demand phase, and the increase in AOC was correlated to the decrease in UV254 during ozonation. The results of MW distribution showed that, ozonation led to the transformation of larger molecules into smaller ones, but the increase in low MW (<1kDa) fraction did not contribute much to AOC production. The change of high MW (>100kDa and 10-100kDa) fractions itself during ozonation was the main reason for the increase of AOC levels. Furthermore, the oxidation of organic matters with high MWs (>100kDa and 10-100kDa) resulted in more AOC production than those with low MWs (1-10kDa and <1kDa). The results indicated that removing large molecules in secondary effluents could limit the increase of AOC during ozonation.

  9. Long-term trends and weekday-to-weekend differences in ozone, its precursors, and other secondary pollutants in Atlanta, Georgia

    NASA Astrophysics Data System (ADS)

    Pollack, I. B.; Ryerson, T. B.; Baumann, K.; Edgerton, E. S.; De Gouw, J. A.; Gilman, J.; Graus, M.; Holloway, J.; Lerner, B. M.; Neuman, J. A.; Roberts, J. M.; Veres, P. R.; Warneke, C.; Trainer, M.; Parrish, D. D.

    2013-12-01

    In an environment rich in biogenic volatile organic compounds (VOCs), decreasing concentrations of ozone (-1.3 % yr-1) and other secondary pollutants (-8.2 % yr-1 for nitric acid, HNO3; and -7.9 % yr-1 for peroxyacetyl nitrate, PAN) in Atlanta, Georgia over the past fifteen years are primarily attributed to decreases in local emissions of nitrogen oxides (NOx=NO+NO2). Large reductions in abundances of NOx in the Southeast U.S. over the years (-8.0 % yr-1 for total reactive nitrogen, NOy) are the direct result of control strategies implemented to reduced emissions from electric-power generation plants and on-road motor vehicles. Here, we compile an extensive historical data set of trace gas measurements spanning fifteen years between 1998 and 2013 from a surface monitoring network site in downtown Atlanta (i.e. the SEARCH network Jefferson Street site) and research aircraft (e.g. the 2013 Southeast Atmosphere Study and 1999 Southern Oxidants Study aboard the NOAA P-3 aircraft). With this data set we confirm and extend long-term trends and weekday-to-weekend differences in ozone, its precursors, and other secondary pollutants during summertime in Atlanta. Long-term changes in abundances and enhancement ratios of secondary oxidation products indicate changes in pollutant formation chemistry in Atlanta resulting from the significant decrease in NOx precursor emissions over the past fifteen years. The most noteworthy changes include: 1) an increase in enhancement ratios of odd oxygen (Ox=O3+NO2) to (PAN+HNO3) of +5.5 % yr-1 indicating an increase in ozone production efficiency by a factor of 2 over the fifteen year period, 2) no significant change in the fraction of oxidized NOx out of NOy over time indicating little change in the extent of photochemical processing of the NOx emissions, and 3) a flip in observed ozone concentrations from higher average ozone on weekends to higher average ozone on weekdays after 2004. The observations for Atlanta will also be contrasted

  10. Radiative forcing perturbation due to observed increases in tropospheric ozone at Hohenpeissenberg

    NASA Technical Reports Server (NTRS)

    Wang, Wei-Chyung; Bojkov, Rumen D.; Zhuang, Yi-Cheng

    1994-01-01

    The effect on surface temperature due to changes in atmospheric O3 depends highly on the latitude where the change occurs. Previous sensitivity calculations indicate that ozone changes in the upper troposphere and lower stratosphere are more effective in causing surface temperature change (Wang et al., 1980). Long term ground-based observations show that tropospheric ozone, especially at the tropopause region, has been increasing at middle and high latitudes in the Northern Hemisphere (NATO, 1988; Quadrennial Ozone Symposium, 1992). These increases will enhance the greenhouse effect and increase the radiative forcing to the troposphere-surface system, which is opposite to the negative radiative forcing calculated from the observed stratospheric ozone depletion recently reported in WMO (1992). We used more than two thousands regularly measured ozonesondes providing reliable vertical O3 distribution at Hohenpeissenberg (47N; 11E) for the 1967-1990 to study the instantaneous solar and longwave radiative forcing the two decades 1971-1990 and compare the forcing with those caused by increasing CO2, CH4, N2O, and CFCs. Calculations are also made to compare the O3 radiative forcing between stratospheric depletion and tropospheric increase. Results indicate that the O3 changes will induce a positive radiative forcing dominated by tropospheric O3 increase and the magnitude of the forcing is comparable to that due to CO2 increases during the two decades. The significant implications of the tropospheric O3 increase to the global climate are discussed.

  11. Future Vegetation Damages from Ozone Pollution: Implication for the Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Szopa, S.; Viovy, N.; Friedlingstein, P.; Hauglustaine, D.; Lathière, J.; Ciais, P.

    2006-12-01

    In the carbon cycle, the present-day sinks due to continental biosphere and oceans are of the same magnitude, however the future response of the continental biosphere to modifications such as climatic change is, nowadays, highly uncertain. Many atmospheric parameters are able to significantly affect the terrestrial carbon sink and several of them are subject to modifications due to human activities. In particular, higher atmospheric CO2 is known to have a fertilizer effect on photosynthesis. Anthropogenic emitted NOx can have a fertilizer effect however it could also have adverse effect on productivity through acid rain. Future climate change can reduce the global efficiency of the vegetation to absorb CO2. Ozone, formed by photochemical reactions involving NOx and VOCs, is responsible of physiological alteration and leaf injury on many plants and thus reduce the carbon sequestration. Future levels of surface O3 in emerging regions (eg. Tropical Africa, Latin America, South East Asia) are expected to increase, and can hence have a significant negative impact on crops and forests. Here we examine the potential impact of O3 on the global terrestrial biosphere for recently developed future scenarios of atmospheric composition and compare with the effects of future climate and CO2 on plant productivity. Ozone levels are computed using the multiscale tropospheric chemistry-transport modelling platform LMDz-INCA/CHIMERE. These ozone exposure distributions are then used by a global dynamic vegetation model ORCHIDEE in order to quantify the changes in net primary production of vegetation under several present and future conditions. Results are discussed in detail for regions of interest having both high O3 precursor emissions and large vegetation cover. The effect of ozone changes at the 2030 horizon on the terrestrial biosphere is shown to be moderate compared with that of climate and CO2.

  12. Indomethacin does not inhibit the ozone-induced increase in bronchial responsiveness in human subjects

    SciTech Connect

    Ying, R.L.; Gross, K.B.; Terzo, T.S.; Eschenbacher, W.L. )

    1990-10-01

    Exposure of human subjects to sufficiently high levels of ozone can result in reversible changes in lung function (restrictive in nature) and increases in nonspecific airway responsiveness. Several studies have implicated products of cyclooxygenase metabolism in the mediation of these changes. The purpose of this study was to determine if indomethacin (a cyclooxygenase inhibitor) would alter the changes in the ozone-induced increase in responsiveness to methacholine or the ozone-induced decrease in lung function. Thirteen male subjects underwent three randomly assigned 2-h exposure to 0.4 ppm ozone with alternating 15-min periods of rest and exercise on a cycle ergometer (30 L/min/m2, body surface area). For the 4 days before each of the exposures, the subjects received either indomethacin (150 mg/day) or placebo, or no modification. Of the 13 subjects, only seven had both detectable indomethacin serum levels on the indomethacin Study Day and a significant increase in bronchial responsiveness to methacholine on the No Medication Day. For this group of seven subjects, we found that indomethacin did not alter the ozone-induced increase in bronchial responsiveness to methacholine (decrease in PC100SRaw for the different study days: no medication, -78.4 +/- 5.3% (mean +/- SEM); placebo, -48.9 +/- 12.2%; indomethacin, -64.5 +/- 6.3%; p greater than 0.2), although indomethacin did attenuate the ozone-induced decrease in lung function. The decrease in the FEV1 for the different study days was as follows: no medication, -20.7 +/- 5.0% (mean +/- SEM); placebo, -19.2 +/- 6.3%; indomethacin, -4.8 +/- 3.7% (p less than 0.001).

  13. Ecosystem Consequences of Prolonged Ozone Pollution in the Southern Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Cousins, S.; Battles, J. J.; Cisneros, R.; Esperanza, A.; Swenson, D.

    2015-12-01

    While acute O3 exposure is widely known to damage plant tissues, the chronic effects on long lived organisms such as trees remain unclear. In the southern Sierra Nevada, O3 pollution has afflicted pine-dominated forests for over 40 years. Here we report the results of a long-term study of O3 impact on tree injury, growth, and mortality. Our study employed a network of forest plots along a gradient of O3 pollution with recurring measurements from 1991-2012. Over the same period and locations, summer O3 was monitored via partnership with USNPS and USFS, making this one of the longest known ecosystem studies of O3 pollution and its effects. We found that exposure at the most polluted sites declined 33%, from a W126 index of 20.12 ppm-hrs in 1992 to 13.5 ppm-hrs in 2012. The severity of foliar pollution damage at these sites also declined, from 43.9 on the 0-100 Ozone Injury Index (OII) scale to 34.2, a drop of 22%. At locations with lower O3 exposure, damage declined from OII of 16.9 to 9.2. Mean annual tree mortality rates over the 20 year period, calculated with a profile likelihood approach, were 0.5%/yr (95% CI 0.3 to 0.8 %/yr). This rate is similar to that of healthy canopy trees in similar unpolluted stands. However, low and declining tree growth rates reveal possible ecosystem impacts of prolonged exposure to pollution. Across affected sites, mean relative growth rates were 1.1%/yr in 1991-2000, and just 0.9%/yr in 2000-2011, a decline of 15.6% in the second decade. Initial analyses suggest that tree damage is positively correlated with June-October O3, as indicated by previous studies. Further analysis will explore the drivers of ecosystem impacts and roles of other natural and anthropogenic stressors, including variation in climatic water deficit. Understanding the consequences of prolonged O3 exposure on both individual trees and complex forest ecosystems helps identify the hidden environmental costs of tropospheric O3 and potential benefits of cleaner air.

  14. Establishing a conceptual model for photochemical ozone pollution in subtropical Hong Kong

    NASA Astrophysics Data System (ADS)

    Ling, Z. H.; Guo, H.; Zheng, J. Y.; Louie, P. K. K.; Cheng, H. R.; Jiang, F.; Cheung, K.; Wong, L. C.; Feng, X. Q.

    2013-09-01

    Photochemical ozone (O3) formation is related to its precursors and meteorological conditions. A conceptual model of O3 air pollution is developed based on the analysis of data obtained at Tung Chung (TC) in Hong Kong. By comparing meteorological parameters between O3 and non-O3 episode days, it was found that high temperatures, strong solar radiation, low wind speeds and relative humidity, northeasterly and/or northwesterly prevailing winds were favorable for the O3 formation, while tropical cyclones were most conducive to the occurrence of O3 episodes. Backward trajectories simulation and graphical illustration of O3 pollution suggested that super-regional (i.e. central and eastern China) and regional (i.e. Pearl River Delta, southern China) transport was another factor that contributed to high O3 levels in Hong Kong. The photochemical O3 formation, generally VOC-limited in Hong Kong, was controlled by a small number of volatile organic compounds (VOCs). Furthermore, the positive matrix factorization (PMF) simulation suggested that solvent usage and vehicular emissions are the major contributors to ambient VOCs in Hong Kong. Finally, this paper presents recommendations for further O3 research and implementation of O3 control strategies.

  15. Dobson spectrophotometer total ozone measurement errors caused by interfering absorbing species such as SO2, NO2, and photochemically produced O3 in polluted air

    NASA Astrophysics Data System (ADS)

    Komhyr, W. D.; Evans, R. D.

    1980-02-01

    Total ozone measurements made with Dobson spectrophotometers in polluted air are subject to errors caused by interfering trace gas species that absorb solar ultraviolet radiation. While such interference is probably non-existent or small at the majority of Dobson instrument stations throughout the world, errors of up to 25% and 5%, resulting from absorption by SO2 and NO2 respectively, may occur occasionally at a few stations located in extremely polluted atmospheres. Interference by other absorbers, including N2O5, H2O2, HNO3, acetyldehyde, acetone, and acrolein has been found to be negligible. Ozone produced photochemically in polluted near-surface air may occasionally constitute from 5% to 10% of the atmospheric total ozone column. Such ozone interferes with measurements of atmospheric background total ozone.

  16. Estimating the effects of increased urbanization on surface meteorology and ozone concentrations in the New York City metropolitan region

    NASA Astrophysics Data System (ADS)

    Civerolo, Kevin; Hogrefe, Christian; Lynn, Barry; Rosenthal, Joyce; Ku, Jia-Yeong; Solecki, William; Cox, Jennifer; Small, Christopher; Rosenzweig, Cynthia; Goldberg, Richard; Knowlton, Kim; Kinney, Patrick

    Land use and pollutant emission changes can have significant impacts on air quality, regional climate, and human health. Here we describe a modeling study aimed at quantifying the potential effects of extensive changes in urban land cover in the New York City (NYC), USA metropolitan region on surface meteorology and ozone (O 3) concentrations. The SLEUTH land-use change model was used to extrapolate urban land cover over this region from "present-day" (ca. 1990) conditions to a future year (ca. 2050), and these projections were subsequently integrated into meteorological and air quality simulations. The development of the future-year land-use scenario followed the narrative of the "A2" scenario described by the Intergovernmental Panel on Climate Change (IPCC), but was restricted to the greater NYC area. The modeling system consists of the Penn State/NCAR MM5 mesoscale meteorological model; the Sparse Matrix Operator Kernal Emissions processing system; and the US EPA Community Multiscale Air Quality model, and simulations were performed for two 18-day episodes, one near-past and one future. Our results suggest that extensive urban growth in the NYC metropolitan area has the potential to increase afternoon near-surface temperatures by more than 0.6 °C and planetary boundary layer (PBL) heights by more than 150 m, as well as decrease water vapor mixing ratio by more than 0.6 g kg -1, across the NYC metropolitan area, with the areal extent of all of these changes generally coinciding with the area of increased urbanization. On the other hand, the impacts of these land use changes on ozone concentrations are more complex. Simulation results indicate that future changes in urbanization, with emissions held constant, may lead to increases in episode-average O 3 levels by about 1-5 ppb, and episode-maximum 8 h O 3 levels by more than 6 ppb across much of the NYC area. However, spatial patterns of ozone changes are heterogeneous and also indicate the presence of areas with

  17. Foliar response of an Ailanthus altissima clone in two sites with different levels of ozone-pollution.

    PubMed

    Gravano, Elisabetta; Giulietti, Valentina; Desotgiu, Rosanna; Bussotti, Filippo; Grossoni, Paolo; Gerosa, Giacomo; Tani, Corrado

    2003-01-01

    Potted plants of Ailanthus altissima, produced by root suckers coming from a single symptomatic mother tree, were placed in two sites in the vicinity of Florence (central Italy), with different levels of ozone pollution. These plants were kept in well watered conditions during the period May-September 1999. In the high pollution site (Settignano-SET) the level of ozone exposure (AOT40) reached at the end of the season a value of 31 ppm h, whereas in the "low pollution" site (Cascine-CAS) the exposure to ozone was 11 ppm h. A. altissima showed foliar symptoms in early July at SET and in the second half of July at CAS when exposure values reached 5 ppm h at both sites. However, at the end of August the conditions of the plantlets were rather similar in both sites. Microscopic and ultrastructural analysis were performed at the first onset of symptoms at SET (the CAS leaflets were asymptomatic). Observing the upper leaf surface where the brown stipples were visible, it was found that the cells of the palisade mesophyll displayed loss of chlorophyll and the organelles in the cytoplasm were damaged. Swelling of thylacoids was observed in the CAS leaflets, thus indicating the possible onset of a pre-visual damage. The injured cells were separated from the healthy ones by a layer of callose. We conclude that the sensitivity to ozone of A. altissima leaves is related to its leaf structure, with low leaf density and large intercellular spaces. Cell walls, as well as acting as mechanical barriers against the spread of ozone within the cell, also provide important detoxifying processes.

  18. Artificial light pollution increases nocturnal vigilance in peahens.

    PubMed

    Yorzinski, Jessica L; Chisholm, Sarah; Byerley, Sydney D; Coy, Jeanee R; Aziz, Aisyah; Wolf, Jamie A; Gnerlich, Amanda C

    2015-01-01

    Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). Captive peahens were exposed to either artificial lighting or natural lighting at night. We employed a novel method to record their vigilance behavior by attaching accelerometers to their heads and continuously monitoring their large head movements. We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrates that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences. PMID:26339552

  19. Artificial light pollution increases nocturnal vigilance in peahens

    PubMed Central

    Chisholm, Sarah; Byerley, Sydney D; Coy, Jeanee R.; Aziz, Aisyah; Wolf, Jamie A.; Gnerlich, Amanda C.

    2015-01-01

    Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). Captive peahens were exposed to either artificial lighting or natural lighting at night. We employed a novel method to record their vigilance behavior by attaching accelerometers to their heads and continuously monitoring their large head movements. We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrates that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences. PMID:26339552

  20. Artificial light pollution increases nocturnal vigilance in peahens.

    PubMed

    Yorzinski, Jessica L; Chisholm, Sarah; Byerley, Sydney D; Coy, Jeanee R; Aziz, Aisyah; Wolf, Jamie A; Gnerlich, Amanda C

    2015-01-01

    Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). Captive peahens were exposed to either artificial lighting or natural lighting at night. We employed a novel method to record their vigilance behavior by attaching accelerometers to their heads and continuously monitoring their large head movements. We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrates that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences.

  1. Increased Anion Channel Activity Is an Unavoidable Event in Ozone-Induced Programmed Cell Death

    PubMed Central

    Errakhi, Rafik; Hiramatsu, Takuya; Meimoun, Patrice; Briand, Joël; Iwaya-Inoue, Mari; Kawano, Tomonori; Bouteau, François

    2010-01-01

    Background Ozone is a major secondary air pollutant often reaching high concentrations in urban areas under strong daylight, high temperature and stagnant high-pressure systems. Ozone in the troposphere is a pollutant that is harmful to the plant. Principal Findings By exposing cells to a strong pulse of ozonized air, an acute cell death was observed in suspension cells of Arabidopsis thaliana used as a model. We demonstrated that O3 treatment induced the activation of a plasma membrane anion channel that is an early prerequisite of O3-induced cell death in A. thaliana. Our data further suggest interplay of anion channel activation with well known plant responses to O3, Ca2+ influx and NADPH-oxidase generated reactive oxygen species (ROS) in mediating the oxidative cell death. This interplay might be fuelled by several mechanisms in addition to the direct ROS generation by O3; namely, H2O2 generation by salicylic and abscisic acids. Anion channel activation was also shown to promote the accumulation of transcripts encoding vacuolar processing enzymes, a family of proteases previously reported to contribute to the disruption of vacuole integrity observed during programmed cell death. Significance Collectively, our data indicate that anion efflux is an early key component of morphological and biochemical events leading to O3-induced programmed cell death. Because ion channels and more specifically anion channels assume a crucial position in cells, an understanding about the underlying role(s) for ion channels in the signalling pathway leading to programmed cell death is a subject that warrants future investigation. PMID:20967217

  2. Nitryl chloride as a 'new' radical source and its role in production of ozone in polluted troposphere: an overview of the results from four field campaigns in China

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Tham, Yee Jun; Xue, Likun; Wang, Zhe; Wang, Xinfeng; Wang, Weihao; Wang, Hao; Yun, Hui; Lu, Keding; Shao, Min; Louie, Peter K. K.; Blake, Donald R.; Brown, Steven S.; Zhang, Yuanhang

    2016-04-01

    Nitryl chloride (ClNO2) - a trace gas produced from heterogeneous reactions of dinitrogen pentoxide (N2O5) on aerosols containing chorine - can significantly affect radical budget and concentrations of ozone and other secondary pollutants. However, the abundance, formation kinetics, and impact of ClNO2are not fully understood under different environmental conditions. This presentation gives an overview of recent field campaigns of ClNO2 and related chemical constituents in China, including one at a mountain top (957 m a.s.l) in Hong Kong of South China in winter 2013 and three in North China (urban Ji'nan, semi-rural Wangdu, and Mt Tai (1534 m a.s.l)) in summer 2014. ClNO2 and N2O5 were measured with a chemical ionization mass spectrometry (CIMS) system with iodide as the primary ions. Ambient concentrations of several hundreds ppts and up to 4.7 ppbv of ClNO2were observed in these locations, suggesting existence of elevated ClNO2 in both coastal and inland atmospheres of China. Measurements in North China exhibited generally low concentrations of N2O5, indicative of its fast uptake of on aerosols under aerosol and humid conditions. Indications of anthropogenic sources of chloride were observed at all these sites. The impact of photolysis of ClNO2 on radical budget and ozone enhancement was assessed with a MCM model which was updated with detailed chlorine chemistry and constrained by measurement data for the southern and a northern site. The results show that the ClNO2 could increase ozone production by 2-16% in the following day. Overall, our study re-affirms the need to include ClNO2 related reactions in photochemical models for prediction of ground-level ozone in polluted environments.

  3. The possible influences of the increasing anthropogenic emissions in India on tropospheric ozone and OH

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Li, Weiliang; Zhou, Xiuji; Isaksen, I. S. A.; Sundet, J. K.; He, Jinhai

    2003-11-01

    A 3-D chemical transport model (OSLO CTM2) is used to investigate the influences of the increasing anthropogenic emission in India. The model is capable of reproducing the observational results of the INDOEX experiment and the measurements in summer over India well. The model results show that when NO x and CO emissions in India are doubled, ozone concentration increases, and global average OH decreases a little. Under the effects of the Indian summer monsoon, NO x and CO in India are efficiently transported into the middle and upper troposphere by the upward current and the convective activities so that the NO x , CO, and ozone in the middle and upper troposphere significantly increase with the increasing NO x and CO emissions. These increases extensively influence a part of Asia, Africa, and Europe, and persist from June to September.

  4. Removal of pollutant compounds from water supplies using ozone, ultraviolet light, and a counter, current packed column. Master's thesis

    SciTech Connect

    Kelly, E.L.

    1991-01-01

    Many water pollutants are determined to be carcinogenic and often appear in very low concentrations and still pose a health risk. Conventional water treatment processes cannot remove these contaminants and there is a great demand for the development of alternative removal technologies. The use of ozone and ultraviolet light in a counter current packed column could prove to be an effective treatment process to remove these contaminants.

  5. Multi-model Estimates of Intercontinental Source-Receptor Relationships for Ozone Pollution

    SciTech Connect

    Fiore, A M; Dentener, F J; Wild, O; Cuvelier, C; Schultz, M G; Hess, P; Textor, C; Schulz, M; Doherty, R; Horowitz, L W; MacKenzie, I A; Sanderson, M G; Shindell, D T; Stevenson, D S; Szopa, S; Van Dingenen, R; Zeng, G; Atherton, C; Bergmann, D; Bey, I; Carmichael, G; Collins, W J; Duncan, B N; Faluvegi, G; Folberth, G; Gauss, M; Gong, S; Hauglustaine, D; Holloway, T; Isaksen, I A; Jacob, D J; Jonson, J E; Kaminski, J W; Keating, T J; Lupu, A; Marmer, E; Montanaro, V; Park, R; Pitari, G; Pringle, K J; Pyle, J A; Schroeder, S; Vivanco, M G; Wind, P; Wojcik, G; Wu, S; Zuber, A

    2008-10-16

    Understanding the surface O{sub 3} response over a 'receptor' region to emission changes over a foreign 'source' region is key to evaluating the potential gains from an international approach to abate ozone (O{sub 3}) pollution. We apply an ensemble of 21 global and hemispheric chemical transport models to estimate the spatial average surface O{sub 3} response over East Asia (EA), Europe (EU), North America (NA) and South Asia (SA) to 20% decreases in anthropogenic emissions of the O{sub 3} precursors, NO{sub x}, NMVOC, and CO (individually and combined), from each of these regions. We find that the ensemble mean surface O{sub 3} concentrations in the base case (year 2001) simulation matches available observations throughout the year over EU but overestimates them by >10 ppb during summer and early fall over the eastern U.S. and Japan. The sum of the O{sub 3} responses to NO{sub x}, CO, and NMVOC decreases separately is approximately equal to that from a simultaneous reduction of all precursors. We define a continental-scale 'import sensitivity' as the ratio of the O{sub 3} response to the 20% reductions in foreign versus 'domestic' (i.e., over the source region itself) emissions. For example, the combined reduction of emissions from the 3 foreign regions produces an ensemble spatial mean decrease of 0.6 ppb over EU (0.4 ppb from NA), less than the 0.8 ppb from the reduction of EU emissions, leading to an import sensitivity ratio of 0.7. The ensemble mean surface O{sub 3} response to foreign emissions is largest in spring and late fall (0.7-0.9 ppb decrease in all regions from the combined precursor reductions in the 3 foreign regions), with import sensitivities ranging from 0.5 to 1.1 (responses to domestic emission reductions are 0.8-1.6 ppb). High O{sub 3} values are much more sensitive to domestic emissions than to foreign emissions, as indicated by lower import sensitivities of 0.2 to 0.3 during July in EA, EU, and NA when O{sub 3} levels are typically highest

  6. Multimodel estimates of intercontinental source-receptor relationships for ozone pollution

    NASA Astrophysics Data System (ADS)

    Fiore, A. M.; Dentener, F. J.; Wild, O.; Cuvelier, C.; Schultz, M. G.; Hess, P.; Textor, C.; Schulz, M.; Doherty, R. M.; Horowitz, L. W.; MacKenzie, I. A.; Sanderson, M. G.; Shindell, D. T.; Stevenson, D. S.; Szopa, S.; van Dingenen, R.; Zeng, G.; Atherton, C.; Bergmann, D.; Bey, I.; Carmichael, G.; Collins, W. J.; Duncan, B. N.; Faluvegi, G.; Folberth, G.; Gauss, M.; Gong, S.; Hauglustaine, D.; Holloway, T.; Isaksen, I. S. A.; Jacob, D. J.; Jonson, J. E.; Kaminski, J. W.; Keating, T. J.; Lupu, A.; Marmer, E.; Montanaro, V.; Park, R. J.; Pitari, G.; Pringle, K. J.; Pyle, J. A.; Schroeder, S.; Vivanco, M. G.; Wind, P.; Wojcik, G.; Wu, S.; Zuber, A.

    2009-02-01

    Understanding the surface O3 response over a "receptor" region to emission changes over a foreign "source" region is key to evaluating the potential gains from an international approach to abate ozone (O3) pollution. We apply an ensemble of 21 global and hemispheric chemical transport models to estimate the spatial average surface O3 response over east Asia (EA), Europe (EU), North America (NA), and south Asia (SA) to 20% decreases in anthropogenic emissions of the O3 precursors, NOx, NMVOC, and CO (individually and combined), from each of these regions. We find that the ensemble mean surface O3 concentrations in the base case (year 2001) simulation matches available observations throughout the year over EU but overestimates them by >10 ppb during summer and early fall over the eastern United States and Japan. The sum of the O3 responses to NOx, CO, and NMVOC decreases separately is approximately equal to that from a simultaneous reduction of all precursors. We define a continental-scale "import sensitivity" as the ratio of the O3 response to the 20% reductions in foreign versus "domestic" (i.e., over the source region itself) emissions. For example, the combined reduction of emissions from the three foreign regions produces an ensemble spatial mean decrease of 0.6 ppb over EU (0.4 ppb from NA), less than the 0.8 ppb from the reduction of EU emissions, leading to an import sensitivity ratio of 0.7. The ensemble mean surface O3 response to foreign emissions is largest in spring and late fall (0.7-0.9 ppb decrease in all regions from the combined precursor reductions in the three foreign regions), with import sensitivities ranging from 0.5 to 1.1 (responses to domestic emission reductions are 0.8-1.6 ppb). High O3 values are much more sensitive to domestic emissions than to foreign emissions, as indicated by lower import sensitivities of 0.2 to 0.3 during July in EA, EU, and NA when O3 levels are typically highest and by the weaker relative response of annual

  7. Meteorology-induced variations in the spatial behavior of summer ozone pollution in Central California

    SciTech Connect

    Jin, Ling; Harley, Robert A.; Brown, Nancy J.

    2010-06-23

    Cluster analysis was applied to daily 8 h ozone maxima modeled for a summer season to characterize meteorology-induced variations in the spatial distribution of ozone. Principal component analysis is employed to form a reduced dimension set to describe and interpret ozone spatial patterns. The first three principal components (PCs) capture {approx}85% of total variance, with PC1 describing a general spatial trend, and PC2 and PC3 each describing a spatial contrast. Six clusters were identified for California's San Joaquin Valley (SJV) with two low, three moderate, and one high-ozone cluster. The moderate ozone clusters are distinguished by elevated ozone levels in different parts of the valley: northern, western, and eastern, respectively. The SJV ozone clusters have stronger coupling with the San Francisco Bay area (SFB) than with the Sacramento Valley (SV). Variations in ozone spatial distributions induced by anthropogenic emission changes are small relative to the overall variations in ozone amomalies observed for the whole summer. Ozone regimes identified here are mostly determined by the direct and indirect meteorological effects. Existing measurement sites are sufficiently representative to capture ozone spatial patterns in the SFB and SV, but the western side of the SJV is under-sampled.

  8. Acute ozone exposure increases plasma prostaglandin F2 alpha in ozone-sensitive human subjects

    SciTech Connect

    Schelegle, E.S.; Adams, W.C.; Giri, S.N.; Siefkin, A.D.

    1989-07-01

    Twenty O/sub 3/-sensitive and /sup 2/O O/sub 3/-nonsensitive subjects participated in a study to investigate the effects of disparate O/sub 3/ sensitivity on plasma prostaglandin F2 alpha responses consequent to exposure to ambient O3 concentrations. Subjects were selected from a pool of 75 normal healthy college-aged males who had been previously exposed to 0.35 ppm O3 for 1 h at an exercising VE of 60 L/min. The selection criterion used was the observed decrement in FEV1 after the O/sub 3/ exposure: O/sub 3/-sensitive, FEV1 decrement greater than 24%; O/sub 3/-nonsensitive, FEV1 decrement less than 11%. Each subject was exposed to filtered air and to 0.20 and 0.35 ppm O/sub 3/ for 80 min while exercising at a VE of 50 L/min. These experimental protocols were divided into two 40-min sessions separated by a period of 4 to 10 min. PGF2 alpha, FVC, FEV1, and FEF25-75 were evaluated before, during, and after each protocol. SGaw and Vtg were measured before and after each protocol. Plasma PGF2 alpha was significantly increased in the O/sub 3/-sensitive group during and after the 0.35-ppm O/sub 3/ exposure.

  9. Air pollution and childhood respiratory health: Exposure to sulfate and ozone in 10 Canadian Rural Communities

    SciTech Connect

    Stern, B.R.; Raizenne, M.E.; Burnett, R.T.; Jones, L.; Kearney, J.; Franklin, C.A. )

    1994-08-01

    This study was designed to examine differences in the respiratory health status of preadolescent school children, aged 7-11 years, who resided in 10 rural Canadian communities in areas of moderate and low exposure to regional sulfate and ozone pollution. Five of the communities were located in central Saskatchewan, a low-exposure region, and five were located in southwestern Ontario, an area with moderately elevated exposures resulting from long-range atmospheric transport of polluted air masses. In this cross-sectional study, the child's respiratory symptoms and illness history were evaluated using a parent-completed questionnaire, administered in September 1985. Respiratory function was assessed once for each child in the schools between October 1985 and March 1986, by the measurement of pulmonary function for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV[sub 1.0]), peak expiratory flow rate (PEFR), mean forced expiratory flow rate during the middle half of the FVC curve (FEF[sub 25-75]), and maximal expiratory flow at 50% of the expired vital capacity (V[sub 50]max). After controlling for the effects of age, sex, parental smoking, parental education and gas cooking, no significant regional differences were observed in rates of chronic cough or phlegm, persistent wheeze, current asthma, bronchitis in the past year, or any chest illness that kept the child at home for 3 or more consecutive days during the previous year. Children living in southwestern Ontario had statistically significant (P < 0.01) mean decrements of 1.7% in FVC and 1.3% in FEV[sub 1.0] compared with Saskatchewan children, after adjusting for age, sex, weight, standing height, parental smoking, and gas cooking. There were no statistically significant regional differences in the pulmonary flow parameters (P > 0.05). 54 refs., 1 fig., 7 tabs.

  10. Photochemical age of air pollutants, ozone, and secondary organic aerosol in transboundary air observed on Fukue Island, Nagasaki, Japan

    NASA Astrophysics Data System (ADS)

    Irei, Satoshi; Takami, Akinori; Sadanaga, Yasuhiro; Nozoe, Susumu; Yonemura, Seiichiro; Bandow, Hiroshi; Yokouchi, Yoko

    2016-04-01

    Study in summer 2002. The similarity may imply the production of similar SOA component, possibly humic-like substances. Meanwhile, the comparison of t[OH] with O3 mixing ratio showed that there was a strong proportional relationship between O3 mixing ratio and t[OH]. A first approximation gave the increasing rate and background mixing ratio of ozone as (3.48 ± 0.06) × 10-7 × [OH] ppbv h-1 and 30.7 ppbv, respectively. The information given here can be used for prediction of secondary pollution magnitude in the outflow from the Asian continent.

  11. Interactions of fire emissions and urban pollution over California: Ozone formation and air quality simulations

    NASA Astrophysics Data System (ADS)

    Singh, H. B.; Cai, C.; Kaduwela, A.; Weinheimer, A.; Wisthaler, A.

    2012-09-01

    An instrumented DC-8 aircraft was employed to perform airborne observations in rural and urban environs of California during the summer 2008 NASA ARCTAS-CARB campaign. The fortuitous occurrence of large wildfire episodes in Northern California allowed for studies of fire emissions, their composition, and their interactions with rural and urban air. Relative to CO, emissions of HCN were shown to vary non-linearly with fire characteristics while those of CH3CN were nearly unchanged, making the latter a superior quantitative tracer of biomass combustion. Although some fire plumes over California contained little NOx and virtually no O3 enhancement, others contained ample VOCs and sufficient NOx, largely from urban influences, to result in significant ozone formation. The highest observed O3 mixing ratios (170 ppb) were also in fire-influenced urban air masses. Attempts to simulate these interactions using CMAQ, a high-resolution state of the art air quality model, were only minimally successful and indicated several shortcomings in simulating fire emission influences on urban smog formation. A variety of secondary oxidation products (e.g. O3, PAN, HCHO) were substantially underestimated in fire-influenced air masses. Available data involving fire plumes and anthropogenic pollution interactions are presently quite sparse and additional observational and mechanistic studies are needed.

  12. UV dosage levels in summer: increased risk of ozone loss from convectively injected water vapor.

    PubMed

    Anderson, James G; Wilmouth, David M; Smith, Jessica B; Sayres, David S

    2012-08-17

    The observed presence of water vapor convectively injected deep into the stratosphere over the United States can fundamentally change the catalytic chlorine/bromine free-radical chemistry of the lower stratosphere by shifting total available inorganic chlorine into the catalytically active free-radical form, ClO. This chemical shift markedly affects total ozone loss rates and makes the catalytic system extraordinarily sensitive to convective injection into the mid-latitude lower stratosphere in summer. Were the intensity and frequency of convective injection to increase as a result of climate forcing by the continued addition of CO(2) and CH(4) to the atmosphere, increased risk of ozone loss and associated increases in ultraviolet dosage would follow.

  13. Asian Outflow and Trans-Pacific Transport of Carbon Monoxide and Ozone Pollution: An Integrated Satellite, Aircraft, and Model Perspective

    NASA Technical Reports Server (NTRS)

    Heald, Colette L.; Jacob, Daniel J.; Fiore, Arlene M.; Emmons, Louisa K.; Gille, John C.; Deeter, Merritt N.; Warner, Ju-Ying; Edwards, David P.; Crawford, James H.; Hamlin, Amy J.

    2003-01-01

    Satellite observations of carbon monoxide (CO) from the Measurements of Pollution in the Troposphere (MOPITT) instrument are combined with measurements from the Transport and Chemical Evolution Over the Pacific (TRACE-P) aircraft mission over the northwest Pacific and with a global three-dimensional chemical transport model (GEOS-CHEM) to quantify Asian pollution outflow and its trans-Pacific transport during spring 2001. Global CO column distributions in MOPITT and GEOS-CHEM are highly correlated (R(exp 2) = 0.87), with no significant model bias. The largest regional bias is over Southeast Asia, where the model is 18% too high. A 60% decrease of regional biomass burning emissions in the model (to 39 Tg/yr) would correct the discrepancy; this result is consistent with TRACE-P observations. MOPITT and TRACE-P also give consistent constraints on the Chinese source of CO from fuel combustion (181 Tg CO/yr). Four major events of trans-Pacific transport of Asian pollution in spring 2001 were seen by MOPITT, in situ platforms, and GEOS-CHEM. One of them was sampled by TRACE-P (26-27 February) as a succession of pollution layers over the northeast Pacific. These layers all originated from one single event of Asian outflow that split into northern and southern plumes over the central Pacific. The northern plume (sampled at 6-8 km off California) had no ozone enhancement. The southern subsiding plume (sampled at 2-4 km west of Hawaii) contained a 8 - 17 ppbv ozone enhancement, driven by decomposition of peroxyacetylnitrate (PAN) to nitrogen oxides (NOx). This result suggests that PAN decomposition in trans-Pacific pollution plumes subsiding over the United States could lead to significant enhancements of surface ozone.

  14. Increased mortality in Philadelphia associated with daily air pollution concentrations

    SciTech Connect

    Schwartz, J.; Dockery, D.W. )

    1992-03-01

    Cause-specific deaths by day for the years 1973 to 1980 in Philadelphia, Pennsylvania, were extracted from National Center for Health Statistics mortality tapes. Death from accidents (International Classification of Disease, Revision 9 greater than or equal to 800) and deaths outside of the city were excluded. Daily counts of deaths were regressed using Poisson regression on total suspended particulate (TSP) and/or SO2 on the same day and on the preceding day, controlling for year, season, temperature, and humidity. A significant positive association was found between total mortality (mean of 48 deaths/day) and both TSP (second highest daily mean, 222 micrograms/m3) and SO2 (second highest daily mean, 299 micrograms/m3). The strongest associations were found with the mean pollution of the current and the preceding days. Total mortality was estimated to increase by 7% (95% CI, 4 to 10%) with each 100-micrograms/m3 increase in TSP, and 5% (95% CI, 3 to 7%) with each 100-micrograms/m3 increase in SO2. When both pollutants were considered simultaneously, the SO2 association was no longer significant. Mortality increased monotonically with TSP. The effect of 100 micrograms/m3 TSP was stronger in subjects older than 65 yr of age (10% increase) compared with those younger than 65 yr of age (3% increase). Cause-specific mortality was also associated with a 100-micrograms/m3 increase in TSP: chronic obstructive pulmonary disease (ICD9 490-496), +19% (95% CI, 0 to 42%), pneumonia (ICD9 480-486 and 507), +11% (95% CI, -3 to +27%), and cardiovascular disease (ICD9 390-448), +10% (95% CI, 6 to 14%). These results are somewhat higher than previously reported associations, and they add to the body of evidence showing that particulate pollution is associated with increased daily mortality at current levels in the United States.

  15. Field Observations of Increased Isoprene Emissions Under Ozone Fumigation: Implications for Tropospheric Chemistry?

    NASA Astrophysics Data System (ADS)

    Sparks, J. P.; Greenberg, J. P.; Harley, P. C.; Guenther, A. B.

    2003-12-01

    Isoprene is the most abundant biogenic hydrocarbon released from vegetation and plays a key role in the chemistry of the lower atmosphere. Isoprene is produced and emitted by many plant species, yet the reason plants produce this seemingly wasteful carbon compound is still in debate in the plant physiology community. It has been proposed that isoprene may protect plant leaves from thermal damage or damage from oxidant exposure by stabilizing cellular and chloroplast membranes or by direct reactions between exogenous isoprene and oxidative species. As part of the Chemical Emission, Loss, Transformation and Interactions within Canopies (CELTIC) study held at Duke Forest during the summer of 2003, we used dynamic cuvette systems to fumigate leaves of sweet gum (Liquidambar styraciflua) with ozone at partial pressures ranging from 0 to 300 ppbv. During fumigations, the effluent air was monitored using infrared gas analysis, on-line proton-transfer-reaction mass spectrometry (PTR-MS) and gas chromatography to quantify changes in partial pressure of CO2, water vapor, isoprene and other volatile organics. At fumigations above 100 ppbv ozone, leaf-isoprene emission increased 20-35% compared to pre-fumigation. To our knowledge, this is the first reported observation of increased isoprene emission under ozone fumigation. Over the timescale of our measurements (several hours), isoprene emissions, once elevated, did not decrease even after fumigation levels were reduced. The increase in isoprene emission could potentially be due to upregulation of the isoprene synthase gene or simply an increase in the production (or reallocation) of subcellular isoprene precursor species. However, our measurements did not elucidate or eliminate a particular mechanism. If increases in isoprene emission in response to ozone are common among isoprene emitting species, the feedback implications for the atmosphere could be large. Both a mechanistic understanding of the upregulation process and

  16. Ozone and Other Air Pollutants and the Risk of Congenital Heart Defects

    PubMed Central

    Zhang, Bin; Zhao, Jinzhu; Yang, Rong; Qian, Zhengmin; Liang, Shengwen; Bassig, Bryan A.; Zhang, Yiming; Hu, Ke; Xu, Shunqing; Dong, Guanghui; Zheng, Tongzhang; Yang, Shaoping

    2016-01-01

    The objective of this study was to evaluate whether high levels of maternal exposure to O3, SO2, NO2, CO are related to increased risk of congenital heart defects (CHDs) in Wuhan, China. The study included mothers living in the central districts of Wuhan during pregnancy over the two-year period from June 10, 2011 to June 9, 2013. For each study participant, we assigned 1-month averages of O3, SO2, NO2 and CO exposure based on measurements obtained from the nearest exposure monitor to the living residence of mothers during their early pregnancy period. In one-pollutant model, we observed an increased risk of CHDs, ventricular septal defect (VSD), and tetralogy of fallot (TF) with increasing O3 exposure. In two-pollutant model, associations with all CHDs, VSD, and TF for O3 were generally consistent compared to the models that included only O3, with the strongest aORs observed for exposures during the third month of pregnancy. We also observed a positive association between CO exposures during the third month of pregnancy and VSD in two pollution model.Our results contribute to the small body of evidence regarding air pollution exposure and CHDs, but confirmation of these associations will be needed in future studies. PMID:27752048

  17. Effects of ozone and other pollutants on the pulmonary function of adult hikers.

    PubMed Central

    Korrick, S A; Neas, L M; Dockery, D W; Gold, D R; Allen, G A; Hill, L B; Kimball, K D; Rosner, B A; Speizer, F E

    1998-01-01

    This study evaluated the acute effects of ambient ozone (O3), fine particulate matter (PM2.5), and strong aerosol acidity on the pulmonary function of exercising adults. During the summers of 1991 and 1992, volunteers (18-64 years of age) were solicited from hikers on Mt. Washington, New Hampshire. Volunteer nonsmokers with complete covariates (n = 530) had pulmonary function measured before and after their hikes. We calculated each hiker's posthike percentage change in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), the ratio of these two (FEV1/FVC), forced expiratory flow between 25 and 75% of FVC(FEF25-75%), and peak expiratory flow rate (PEFR). Average O3 exposures ranged from 21 to 74 ppb. After adjustment for age,sex, smoking status (former versus never), history of asthma or wheeze, hours hiked, ambient temperature, and other covariates, there was a 2.6% decline in FEV1 [95% confidence interval (CI), 0.4-4.7; p = 0.02] and a 2.2% decline in FVC (CI, 0.8-3.5; p =0.003) for each 50 ppb increment in mean O3. There were consistent associations of decrements in both FVC (0.4% decline; CI,0.2-0.6, p = 0.001) and PEFR (0.8% decline; CI, 0.01-1.6; p = 0.05) with PM2.5 and of decrements in PEFR (0.4% decline; CI, 0.1-0.7; p = 0.02) with strong aerosol acidity across the interquartile range of these exposures. Hikers with asthma or a history of wheeze (n = 40) had fourfold greater responsiveness to ozone than others. With prolonged outdoor exercise, low-level exposures to O3, PM2.5, and strong aerosol acidity were associated with significant effects on pulmonary function among adults. Hikers with a history of asthma or wheeze had significantly greater air pollution-related changes in pulmonary function. Images Figure 1 Figure 2 PMID:9435151

  18. Exposure to automotive pollution increases plasma susceptibility to oxidation.

    PubMed

    Sharman, James E; Coombes, Jeff S; Geraghty, Dominic P; Fraser, David I

    2002-01-01

    Low-density lipoprotein oxidation is implicated in the development of atherosclerosis. Plasma susceptibility to oxidation may be used as a marker of low-density lipoprotein oxidation and thus predict atherosclerotic risk. In this study the authors investigated the relationship between plasma susceptibility to oxidation and exposure to automotive pollution in a group of automobile mechanics (n = 16) exposed to high levels of automotive pollution, vs. matched controls (n = 13). The authors induced plasma oxidation by a free radical initiator and they determined susceptibility to oxidation by (1) change in absorbance at 234 nm, (2) lag time to conjugated diene formation, and (3) linear slope of the oxidation curve. Mechanics had significantly higher values (mean +/- standard error) for change in absorbance (1.60 +/- 0.05 vs. 1.36 +/- 0.05; p < .002), and slope (1.6 x 10(-3) +/- 0.1 x 10(-3) vs. 1.3 x 10(-3) +/- 0.1 x 10(-3); p < .001), compared with controls. These results indicate that regular exposure to automotive pollutants increases plasma susceptibility to oxidation and may, in the long-term, increase the risk of developing atherosclerosis.

  19. Increasingly intolerable boundaries: future control of environmental pollution.

    PubMed

    Scanlon, J

    2001-09-14

    In recent years, there have been a number of toxic accidents on the sea and on land which have caused pollution down current, down wind and down stream. Four were dramatic and these four have led to substantial changes in the way we deal with risk to the environment. There have also been increasing concerns about a less spectacular but equally concerning problem, acid rain, though attempts to deal with this problem have been less successful. Perhaps the drama was lacking. In all these cases, unfortunately, the less developed countries can ill afford the costs of prevention and this means they are often the home of environmentally unfriendly development. While the current approaches to such problems will continue, it is likely that the countries on the receiving end of such pollution, especially if they have economic and military power, will seek more forceful solutions. One outcome may be a UN-sponsored environmental police force.

  20. Rapid increases in tropospheric ozone production and export from China: A view from AURA and TM5

    NASA Astrophysics Data System (ADS)

    Verstraeten, W. W.; Neu, J. L.; Williams, J. E.; Bowman, K. W.; Worden, J. R.; Boersma, K. F.

    2015-12-01

    Eastern Asia has the fastest growing anthropogenic emissions in the world, possibly affecting both the pollution in the local troposphere as well as in the trans-Pacific region. Local measurements over Asia show that tropospheric ozone (O3) has increased by 1 to 3% per year since the start of the millennium. This increase is often invoked to explain positive tropospheric O3 trends observed in western US, but to date there is no unambiguous evidence showing that enhanced Asian pollution is responsible for these trends. In this research we use observations of tropospheric O3 from TES (Tropospheric Emission Spectrometer, onboard AURA), tropospheric NO2 measurements from OMI (Ozone Monitoring Instrument, onboard AURA) and lower stratospheric observations of O3 from MLS (Microwave Limb Sounder, onboard AURA) in combination with the TM5 CTM. Satellite-based studies focusing on tropospheric O3 and NO2 have the potential to close the gap left by previous studies on air quality since spaceborne data provide large-scale observational evidence that both O3 precursor concentrations and tropospheric O3 levels are rapidly changing over source receptor areas. We show the increased ability of TM5 to reproduce the 2005-2010 observed rapid rise in free tropospheric O3 of 7% over China from TES, once OMI NO2 measurements were implemented in TM5 to update NOX emissions. MLS observations on lower stratospheric O3 have the potential to improve the stratosphere-troposphere exchange (STE) estimate in TM5 which is mainly driven by ECMWF meteorological fields. Constraining the TM5 modelled trend of the STE contribution to the 3-9 km partial O3 column using MLS observations of stratospheric O3 lead to a better explanation of the sources of the free tropospheric O3 trends over China. Based on the OMI inferred TM5 updates in NOX emissions, the impact of Asian O3 and its precursors on the free troposphere (3-9 km) over the western US could be quantified. Large import from China offsets the

  1. Degradation and rearrangement of a lung surfactant lipid at the air-water interface during exposure to the pollutant gas ozone.

    PubMed

    Thompson, Katherine C; Jones, Stephanie H; Rennie, Adrian R; King, Martin D; Ward, Andrew D; Hughes, Brian R; Lucas, Claire O M; Campbell, Richard A; Hughes, Arwel V

    2013-04-01

    The presence of unsaturated lipids in lung surfactant is important for proper respiratory function. In this work, we have used neutron reflection and surface pressure measurements to study the reaction of the ubiquitous pollutant gas-phase ozone, O3, with pure and mixed phospholipid monolayers at the air-water interface. The results reveal that the reaction of the unsaturated lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, POPC, with ozone leads to the rapid loss of the terminal C9 portion of the oleoyl strand of POPC from the air-water interface. The loss of the C9 portion from the interface is accompanied by an increase in the surface pressure (decrease in surface tension) of the film at the air-water interface. The results suggest that the portion of the oxidized oleoyl strand that is still attached to the lipid headgroup rapidly reverses its orientation and penetrates the air-water interface alongside the original headgroup, thus increasing the surface pressure. The reaction of POPC with ozone also leads to a loss of material from the palmitoyl strand, but the loss of palmitoyl material occurs after the loss of the terminal C9 portion from the oleoyl strand of the molecule, suggesting that the palmitoyl material is lost in a secondary reaction step. Further experiments studying the reaction of mixed monolayers composed of unsaturated lipid POPC and saturated lipid dipalmitoyl-sn-glycero-3-phosphocholine, DPPC, revealed that no loss of DPPC from the air-water interface occurs, eliminating the possibility that a reactive species such as an OH radical is formed and is able to attack nearby lipid chains. The reaction of ozone with the mixed films does cause a significant change in the surface pressure of the air-water interface. Thus, the reaction of unsaturated lipids in lung surfactant changes and impairs the physical properties of the film at the air-water interface.

  2. Tropospheric Ozone Increases in the TTL over the Southern African Region (1990-2007): Insights from Sonde and Aircraft Profiles

    NASA Astrophysics Data System (ADS)

    Balashov, N. V.; Thompson, A. M.; Kollonige, D. E.; Coetzee, G.; Thouret, V.; Posny, F.

    2013-12-01

    Ozonesonde records from the early 1990s through 2007 over two subtropical stations, Irene (near Pretoria, South Africa) and Réunion Island (21S, 55W, ~3500 km NE of Irene in the southwest Indian Ocean) have been reported to exhibit free tropospheric (FT) ozone increases. We re-analyzed FT ozone in the1990-2007 Irene sondes, filling in mid-1990s gaps with ozone profiles taken by Measurements of Ozone by Airbus In-service Aircraft (MOZAIC) over nearby Johannesburg. We applied a multivariate regression model to monthly averaged data from the combined dataset as well as to 1992-2011 FT and TTL ozone from Réunion sondes. Taking into account terms for the seasonal cycle, ENSO, and potential vorticity (PV) anomalies, we found that: (1) Statistically significant trends appear predominantly in the middle troposphere up to the tropopause layer (6-11 km over Irene, 6-15 km over Réunion) in winter (June-August), with an increase ~ 1 ppbv/yr over Irene and ~2 ppbv/yr over Réunion. Both stations display a less intense ozone increase above 7 km in November-December. (2) Variability in TTL dynamics and stratosphere-troposphere interactions were considered as plausible explanations for the Irene ozone increases. For the spring, there is a pronounced sensitivity to PV anomalies (+ 70 ppbv ozone/PV unit). We compare these results to our prior study of TTL wave activity at Irene and Réunion and relationships among waves, TTL ozone variability and oscillations like the ENSO. Trend (change in ppbv ozone/year) computed from multivariate regression model for 4-15 km, profiles from Réunion sondes, 1992-2011. Diagonal shading denotes statistical significance.

  3. Distribution of ozone and other air pollutants in forests of the Carpathian Mountains in central Europe.

    PubMed

    Bytnerowicz, A; Godzik, B; Fraczek, W; Grodzińska, K; Krywult, M; Badea, O; Barancok, P; Blum, O; Cerny, M; Godzik, S; Mankovska, B; Manning, W; Moravcik, P; Musselman, R; Oszlanyi, J; Postelnicu, D; Szdźuj, J; Varsavova, M; Zota, M

    2002-01-01

    Ozone (O3) concentrations were monitored during the 1997-1999 growing seasons in 32 forest sites of the Carpathian Mountains. At all sites (elevation between 450 and 1320 m) concentrations of O3, nitrogen dioxide (NO2), and sulfur dioxide (SO2) were measured with passive samplers. In addition, in two western Carpathian locations, Vychodna and Gubalówka, ozone was continuously monitored with ultraviolet (UV) absorption monitors. Highest average hourly O3 concentrations in the Vychodna and Gubałówka sites reached 160 and 200 microg/m3 (82 and 102 ppb), respectively (except for the AOT40 values, ozone concentrations are presented as microg/m3; and at 25 degrees C and 760 mm Hg, 1 microg O3/m3 = 0.51 ppb O3). These sites showed drastically different patterns of diurnal 03 distribution, one with clearly defined peaks in the afternoon and lowest values in the morning, the other with flat patterns during the entire 24-h period. On two elevational transects, no effect of elevation on O3 levels was seen on the first one, while on the other a significant increase of O3 levels with elevation occurred. Concentrations of O3 determined with passive samplers were significantly different between individual monitoring years, monitoring periods, and geographic location of the monitoring sites. Results of passive sampler monitoring showed that high O3 concentrations could be expected in many parts of the Carpathian range, especially in its western part, but also in the eastern and southern ranges. More than four-fold denser network of monitoring sites is required for reliable estimates of O3 distribution in forests over the entire Carpathian range (140 points). Potential phytotoxic effects of O3 on forest trees and understory vegetation are expected on almost the entire territory of the Carpathian Mountains. This assumption is based on estimates of the AOT40 indices for forest trees and natural vegetation. Concentrations of NO2 and SO2 in the entire Carpathian range were typical

  4. Reducing Nitrogen Pollution while Decreasing Farmers' Costs and Increasing Fertilizer Industry Profits.

    PubMed

    Kanter, David R; Zhang, Xin; Mauzerall, Denise L

    2015-03-01

    Nitrogen (N) pollution is emerging as one of the most important environmental issues of the 21st Century, contributing to air and water pollution, climate change, and stratospheric ozone depletion. With agriculture being the dominant source, we tested whether it is possible to reduce agricultural N pollution in a way that benefits the environment, reduces farmers' costs, and increases fertilizer industry profitability, thereby creating a "sweet spot" for decision-makers that could significantly increase the viability of improved N management initiatives. Although studies of the economic impacts of improved N management have begun to take into account farmers and the environment, this is the first study to consider the fertilizer industry. Our "sweet spot" hypothesis is evaluated via a cost-benefit analysis of moderate and ambitious N use efficiency targets in U.S. and China corn sectors over the period 2015-2035. We use a blend of publicly available crop and energy price projections, original time-series modeling, and expert elicitation. The results present a mixed picture: although the potential for a "sweet spot" exists in both countries, it is more likely that one occurs in China due to the currently extensive overapplication of fertilizer, which creates a greater potential for farmers and the fertilizer industry to gain economically from improved N management. Nevertheless, the environmental benefits of improving N management consistently dwarf the economic impacts on farmers and the fertilizer industry in both countries, suggesting that viable policy options could include incentives to farmers and the fertilizer industry to increase their support for N management policies. PMID:26023952

  5. The Nevada Rural Ozone Initiative (NVROI): Insights to understanding air pollution in complex terrain.

    PubMed

    Gustin, Mae Sexauer; Fine, Rebekka; Miller, Matthieu; Jaffe, Dan; Burley, Joel

    2015-10-15

    The Nevada Rural Ozone Initiative (NVROI) was established to better understand O3 concentrations in the Western United States (US). The major working hypothesis for development of the sampling network was that the sources of O3 to Nevada are regional and global. Within the framework of this overarching hypothesis, we specifically address two conceptual meteorological hypotheses: (1) The high elevation, complex terrain, and deep convective mixing that characterize Nevada, make this state ideally located to intercept polluted parcels of air transported into the US from the free troposphere; and (2) site specific terrain features will influence O3 concentrations observed at surface sites. Here, the impact of complex terrain and site location on observations are discussed. Data collected in Nevada at 6 sites (1385 to 2082 m above sea level (asl)) are compared with that collected at high elevation sites in Yosemite National Park and the White Mountains, California. Average daily maximum 1-hour concentrations of O3 during the first year of the NVROI ranged from 58 to 69 ppbv (spring), 53 to 62 ppbv (summer), 44 to 49 ppbv (fall), and 37 to 45 ppbv (winter). These were similar to those measured at 3 sites in Yosemite National Park (2022 to 3031 m asl), and at 4 sites in the White Mountains (1237 to 4342 m asl) (58 to 67 ppbv (summer) and 47 to 58 ppbv (fall)). Results show, that in complex terrain, collection of data should occur at high and low elevation sites to capture surface impacts, and site location with respect to topography should be considered. Additionally, concentrations measured are above the threshold reported for causing a reduction in growth and visible injury for plants (40 ppbv), and sustained exposure at high elevation locations in the Western USA may be detrimental for ecosystems.

  6. Quantitative comparisons of various air pollutant emission sources of ozone precursors in East Tennessee - a study evaluated from the emission inventory development

    SciTech Connect

    Bandyopadhyay, N.

    1996-12-31

    The United States Department of the Interior has raised concerns regarding air pollution impacts in the Great Smoky Mountains National Park (GSMNP). The formation of the Southern Appalachian Mountains Initiative (SAMI) is regional effort to understand the air quality impacts of emission sources upon the Appalachian Mountains. The Tennessee Division of Air Pollution Control (TDAPC) has recently committed additional resources for the analyses of proposals for increased emissions of air pollutants in East Tennessee. The TDAPC has planned to assess these effects by conducting an air quality modeling project. The United States Environmental Protection Agency`s (US EPA`s) Urban Airshed Model (UAM) has been used as the primary air quality model for this purpose. The purpose of this project will be to evaluate the expected impact of any major new or modified air pollution source located in Tennessee on ozone in the GSMNP. An accurate emission inventory is essential to any air quality modeling analysis. A modeling inventory has been developed by the TDAPC for the base year 1993. The modeling area includes 40 counties in East and Middle Tennessee and 42 counties in neighboring states. For the counties in Tennessee, a detailed inventory of the point sources was prepared. For the other states inside the modeling domain, the EPA`s Aerometric Information Retrieval System (AIRS)-AIRS Facility Subsystem (AFS) was used to obtain point source data, The accuracy of the AFS data for the other states was not addressed, A detailed quantitative analysis has been conducted with the emission inventory developed for Tennessee counties. The purpose of this study is to quantify the relative contributions of the emissions of Volatile Organic Compounds (VOCs) and Nitrogen Oxides (NO{sub x}) from different point, area, mobile and biogenic sources to ozone formation in the vicinity of the GSMNP.

  7. Ozone and cardiovascular injury.

    PubMed

    Srebot, Vera; Gianicolo, Emilio A L; Rainaldi, Giuseppe; Trivella, Maria Giovanna; Sicari, Rosa

    2009-06-24

    Air pollution is increasingly recognized as an important and modifiable determinant of cardiovascular diseases in urban communities. The potential detrimental effects are both acute and chronic having a strong impact on morbidity and mortality. The acute exposure to pollutants has been linked to adverse cardiovascular events such as myocardial infarction, heart failure and life-threatening arrhythmias. The long-terms effects are related to the lifetime risk of death from cardiac causes. The WHO estimates that air pollution is responsible for 3 million premature deaths each year. The evidence supporting these data is very strong nonetheless, epidemiologic and observational data have the main limitation of imprecise measurements. Moreover, the lack of clinical experimental models makes it difficult to demonstrate the individual risk. The other limitation is related to the lack of a clear mechanism explaining the effects of pollution on cardiovascular mortality. In the present review we will explore the epidemiological, clinical and experimental evidence of the effects of ozone on cardiovascular diseases. The pathophysiologic consequences of air pollutant exposures have been extensively investigated in pulmonary systems, and it is clear that some of the major components of air pollution (e.g. ozone and particulate matter) can initiate and exacerbate lung disease in humans 1. It is possible that pulmonary oxidant stress mediated by particulate matter and/or ozone (O3) exposure can result in downstream perturbations in the cardiovasculature, as the pulmonary and cardiovascular systems are intricately associated, and it is well documented that specific environmental toxins (such as tobacco smoke 2) introduced through the lungs can initiate and/or accelerate cardiovascular disease development. Indeed, several epidemiologic studies have proved that there is an association between PM and O3 and the increased incidence of cardiovascular morbidity and mortality 3. Most of the

  8. Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion.

    PubMed

    Parrino, F; Camera-Roda, G; Loddo, V; Palmisano, G; Augugliaro, V

    2014-03-01

    The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated process bromate ions are not produced as long as some oxidizable organics are present.

  9. Alternative ozone metrics and daily mortality in Suzhou: the China Air Pollution and Health Effects Study (CAPES).

    PubMed

    Yang, Chunxue; Yang, Haibing; Guo, Shu; Wang, Zongshuang; Xu, Xiaohui; Duan, Xiaoli; Kan, Haidong

    2012-06-01

    Controversy remains regarding the relationship between various metrics of ozone (O(3)) and mortality. In China, the largest developing country, there have been few studies investigating the acute effect of O(3) on death. We used three exposure metrics of O(3) (1-hour maximum, maximum 8-hour average and 24-hour average) to examine its short-term association with daily mortality in Suzhou, China. We used a Generalized Additive Model (GAM) with penalized splines to analyze the mortality, O(3), and covariate data. We examined the association by season, age group, sex and educational level. We found that the current level of O(3) in Suzhou is associated with death rates from all causes and cardiovascular diseases. Among various metrics of O(3), maximum 8-hour average and 1-hour maximum concentrations seem to be more strongly associated with increased mortality rate compared to 24-hour average concentrations. Using maximum 8-hour average, an inter-quartile range increase of 2-day average O(3) (lag 01) corresponds to 2.15% (95%CI, 0.36 to 3.93), 4.47% (95%CI, 1.43 to 7.51), -1.85% (95%CI, -6.91 to 3.22) increase in all-cause, cardiovascular, and respiratory mortality, respectively. The associations between O(3) and daily mortality appeared to be more evident in the cool season than in the warm season. In conclusion, maximum 8-hour average and 1-hour maximum concentrations of O(3) are associated with daily mortality in Suzhou. Our analyses strengthen the rationale for further limiting levels of O(3) pollution in the city. PMID:22521098

  10. The predicted impact of increased formaldehyde emissions from industrial flares on ozone concentrations in Houston, TX.

    NASA Astrophysics Data System (ADS)

    Wang, C. T.; Vizuete, W.

    2015-12-01

    Houston features one of the largest concentrations of the petrochemical industry in all of North America and flares are widely used there as the final treatment process for unwanted volatile organic compounds. These flares have the potential to produce formaldehyde as the result of incomplete combustion. Formaldehyde emissions are an important precursor to producing hydroxyl radicals and thus can impact atmospheric chemistry and the formation of ozone. Formaldehyde emissions from flares, however, are difficult to measure in situ. Recently, alternative measurement techniques have been developed, like open path optical methods, that allow the direct measurement of flare emissions from the facility's fence line (Johansson et al., 2014; Pikelnaya, Flynn, Tsai, & Stutz, 2013). This observational data indicates that the emission rate of formaldehyde from flares is about 10-20 times greater than those found in the regulatory models developed by the Texas Commission on Environmental Quality's (TCEQ). This research will use air quality models to quantify the impact that increased formaldehyde emission from flares will have on Houston ozone concentrations. This study relies on the CAMx model (version 6.1) and emission data developed by Alpine Geophysics LLC (AG) and Climate & Atmospheric Research Associates (CARA) based on the combined databases from TCEQ, U.S. Environmental Protection Agency (EPA), and National Emission Inventory (NEI2008). This model also used meteorology data from the results of WRF-ARW dynamics. The CAMx generated process analysis data will also be used to quantify changes in radical budgets and NOx budgets critical to ozone production.

  11. Understanding high wintertime ozone pollution events in an oil- and natural gas-producing region of the western US

    NASA Astrophysics Data System (ADS)

    Ahmadov, R.; McKeen, S.; Trainer, M.; Banta, R.; Brewer, A.; Brown, S.; Edwards, P. M.; de Gouw, J. A.; Frost, G. J.; Gilman, J.; Helmig, D.; Johnson, B.; Karion, A.; Koss, A.; Langford, A.; Lerner, B.; Olson, J.; Oltmans, S.; Peischl, J.; Pétron, G.; Pichugina, Y.; Roberts, J. M.; Ryerson, T.; Schnell, R.; Senff, C.; Sweeney, C.; Thompson, C.; Veres, P. R.; Warneke, C.; Wild, R.; Williams, E. J.; Yuan, B.; Zamora, R.

    2015-01-01

    Recent increases in oil and natural gas (NG) production throughout the western US have come with scientific and public interest in emission rates, air quality and climate impacts related to this industry. This study uses a regional-scale air quality model (WRF-Chem) to simulate high ozone (O3) episodes during the winter of 2013 over the Uinta Basin (UB) in northeastern Utah, which is densely populated by thousands of oil and NG wells. The high-resolution meteorological simulations are able qualitatively to reproduce the wintertime cold pool conditions that occurred in 2013, allowing the model to reproduce the observed multi-day buildup of atmospheric pollutants and the accompanying rapid photochemical ozone formation in the UB. Two different emission scenarios for the oil and NG sector were employed in this study. The first emission scenario (bottom-up) was based on the US Environmental Protection Agency (EPA) National Emission Inventory (NEI) (2011, version 1) for the oil and NG sector for the UB. The second emission scenario (top-down) was based on estimates of methane (CH4) emissions derived from in situ aircraft measurements and a regression analysis for multiple species relative to CH4 concentration measurements in the UB. Evaluation of the model results shows greater underestimates of CH4 and other volatile organic compounds (VOCs) in the simulation with the NEI-2011 inventory than in the case when the top-down emission scenario was used. Unlike VOCs, the NEI-2011 inventory significantly overestimates the emissions of nitrogen oxides (NOx), while the top-down emission scenario results in a moderate negative bias. The model simulation using the top-down emission case captures the buildup and afternoon peaks observed during high O3 episodes. In contrast, the simulation using the bottom-up inventory is not able to reproduce any of the observed high O3 concentrations in the UB. Simple emission reduction scenarios show that O3 production is VOC sensitive and NOx

  12. Increasing CO2 Coupled with Other Anthropogenic Perturbations: Effects on Ozone and Other Trace Gases

    NASA Technical Reports Server (NTRS)

    Rosenfield, J. E.; Douglass, A. R.

    1999-01-01

    The GSFC 2D interactive chemistry-radiation-dynamics model has been used to study the effects on stratospheric trace gases of past and future CO2 increases coupled with changes in CFC'S, methane, and nitrous oxide. Previous simulations with the GSFC model showed that the stratospheric cooling calculated to result from doubling atmospheric CO2 would lead, in the absence of a growth of other anthropogenic gases, to a decrease in upper stratospheric NO(y) of roughly 15%. This work has been extended to simulate changes in stratospheric chemistry and dynamics occurring between the years 1960 and 2050. The simulations have been carried out with and without changes in CO2. In the low latitude upper stratosphere ozone is predicted to be 10% greater in 2050 than in 1990 when increased CO2 is included, compared with an increase of only 2% without the inclusion of CO2. In the low latitude lower stratosphere, ozone is predicted to decrease by about 1% between 1990 and 2050 when CO2 changes are taken into account, in contrast to an approximate 3% increase when they are not. The simulated behavior of water vapor is another example of the coupled responses. Between 1990 and 2050 low latitude water vapor is predicted to increase by 4% and 2% in the upper and lower stratosphere, respectively, without the inclusion of CO2 increases. with the inclusion of CO2 changes, the water vapor increases are predicted to be roughly 12% and 8%, for the upper and lower stratosphere, respectively.

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

    EPA Science Inventory

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

  14. The impact of decreases in air temperature and increases in ozone on markers of endothelial function in individuals having type-2 diabetes.

    PubMed

    Lanzinger, Stefanie; Breitner, Susanne; Neas, Lucas; Cascio, Wayne; Diaz-Sanchez, David; Hinderliter, Alan; Peters, Annette; Devlin, Robert B; Schneider, Alexandra

    2014-10-01

    Several studies have reported an association between air pollution and endothelial dysfunction, especially in individuals having diabetes. However, very few studies have examined the impact of air temperature on endothelial function. The objective of this analysis was to investigate short-term effects of temperature and ozone on endothelial function in individuals having diabetes. Moreover, we investigated interactive effects between air temperature and air pollution on markers of endothelial function. Between November 2004 and December 2005 flow-mediated dilatation (FMD), nitroglycerin-mediated dilatation (NTGMD) and several blood markers representing endothelial function were measured using brachial artery ultrasound on four consecutive days in 22 individuals with type-2 diabetes mellitus in Chapel Hill, North Carolina (USA). Daily measurements of meteorological parameters, ozone and particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5) were obtained from fixed monitoring sites. We used additive mixed-models adjusting for time trend, day of the week, relative humidity and barometric pressure to assess temperature and ozone associations with endothelial function. A 1 °C decrease in the 24-h temperature average was associated with a decrease in mean FMD on the same day (-2.2% (95%-confidence interval:[-4.7;0.3%])) and with a delay of one and four days. A temperature decrement also led to an immediate (-1.7%[-3.3;-0.04]) decrease in NTGMD. Moreover, we observed an immediate (-14.6%[-26.3;-2.9%]) and a one day delayed (-13.5%[-27.0; 0.04%]) decrease in FMD in association with a 0.01 ppm increase in the maximum 8-h moving average of ozone. Temperature effects on FMD strengthened when PM2.5 and ozone concentrations were high. The associations were similar during winter and summer. We detected an association between temperature decreases and ozone increases on endothelial dysfunction in individuals having diabetes. We conclude that endothelial dysfunction

  15. Significant increase of summertime ozone at Mount Tai in Central Eastern China

    NASA Astrophysics Data System (ADS)

    Sun, Lei; Xue, Likun; Wang, Tao; Gao, Jian; Ding, Aijun; Cooper, Owen R.; Lin, Meiyun; Xu, Pengju; Wang, Zhe; Wang, Xinfeng; Wen, Liang; Zhu, Yanhong; Chen, Tianshu; Yang, Lingxiao; Wang, Yan; Chen, Jianmin; Wang, Wenxing

    2016-08-01

    Tropospheric ozone (O3) is a trace gas playing important roles in atmospheric chemistry, air quality and climate change. In contrast to North America and Europe, long-term measurements of surface O3 are very limited in China. We compile available O3 observations at Mt. Tai - the highest mountain over the North China Plain - during 2003-2015 and analyze the decadal change of O3 and its sources. A linear regression analysis shows that summertime O3 measured at Mt. Tai has increased significantly by 1.7 ppbv yr-1 for June and 2.1 ppbv yr-1 for the July-August average. The observed increase is supported by a global chemistry-climate model hindcast (GFDL-AM3) with O3 precursor emissions varying from year to year over 1980-2014. Analysis of satellite data indicates that the O3 increase was mainly due to the increased emissions of O3 precursors, in particular volatile organic compounds (VOCs). An important finding is that the emissions of nitrogen oxides (NOx) have diminished since 2011, but the increase of VOCs appears to have enhanced the ozone production efficiency and contributed to the observed O3 increase in central eastern China. We present evidence that controlling NOx alone, in the absence of VOC controls, is not sufficient to reduce regional O3 levels in North China in a short period.

  16. Effect of a chronic and moderate ozone pollution on the phenolic pattern of bean leaves (Phaseolus vulgaris L. cv Nerina): relations with visible injury and biomass production.

    PubMed

    Kanoun, M; Goulas, M J.P.; Biolley, J -P.

    2001-05-01

    From sowing, bean (Phaseolus vulgaris L. cv Nerina) plants were exposed to three chronic doses of ozone for 7h.day(-1): non-filtered air (NF), non-filtered air supplied with 40nl.l(-1) ozone (NF+40) and non-filtered air supplied with 60nll(-1) ozone (NF+60). Four harvests were carried out 6, 13, 20 and 27 days after emergence. Either primary leaves, or first trifoliate leaves, or both were sampled as far as possible. For each sampled leaf, visible ozone injuries were registered, the free polyphenolic pool was analysed using HPLC and the dry matter was weighed. Visible damage on leaves was related to both exposure time and ozone concentration added. There were no adverse effects of added ozone on the biomass of primary leaves while a significant reduction of first trifoliates dry matter could be observed (NF+60 atmosphere, third and fourth harvest). Among the normally occurring phenolics, we detected a significant decrease in the accumulation of a hydroxycinnamic acid derivative as the ozone concentration increased. Nevertheless, we demonstrated that this ozone-induced modification could be sometimes distinguishable with difficulties from changes expected to be of development relevance. Beside this phenolic disbalance, we detected a de novo biosynthesis of compounds that closely depended on the level of visible ozone injury. Since their accumulation increased with leaf damage, these ozone-induced phenolics could be used to detect phytotoxic ambient levels of tropospheric ozone.

  17. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    SciTech Connect

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  18. Climate Impacts of Ozone and Sulfate Air Pollution from Specific Emissions Sectors and Regions

    NASA Astrophysics Data System (ADS)

    Unger, N.; Koch, D. M.; Shindell, D. T.; Streets, D. G.

    2006-12-01

    The secondary air pollutants ozone (O3) and sulfate aerosol are generated by human activities and affect the Earth's climate system. The global mean radiative forcings of these short-lived species depend on the location of the precursor gas emissions, which has so far prevented their incorporation into climate-motivated policy agreements. O3 and sulfate aerosol are strongly coupled through tropospheric photochemistry and yet air quality control efforts consider each species separately. Previous modeling work to assess climate impacts of O3 has focused on individual precursors, such as nitrogen oxides, even though policy action would target a particular sector. We use the G-PUCCINI atmospheric composition-climate model to isolate the O3 and sulfate direct radiative forcing impacts of 6 specific emissions sectors (industry, transport, power, domestic biofuel, domestic fossil fuel and biomass burning) from 7 geographic regions (North America, Europe, South Asia, East Asia, North Africa and the Middle East, Central and South Africa and South America) for the near future 2030 atmosphere. The goal of the study is to identify specific source sectors and regions that present the most effective opportunities to mitigate global warming. At 2030, the industry and power sectors dominate the sulfate forcing across all regions, with East Asia, South Asia and North Africa and Middle East contributing the largest sulfate forcings (-100 to 120 mWm-2). The transport sector represents an important O3 forcing from all regions ranging from 5 mWm-2 (Europe) to 12 mWm-2 (East Asia). Domestic biofuel O3 forcing is important for the East Asia (13 mWm-2), South Asia (7 mWm-2) and Central and South Africa (10 mWm-2) regions. Biomass burning contributes large O3 forcings for the Central and South Africa (15 mWm-2) and South America (11 mWm-2) regions. In addition, the power sector O3 forcings from East Asia (14 mWm-2) and South Asia (8 mWm-2) are also substantial. Considering the sum of the O

  19. Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution.

    PubMed

    Hewitt, C N; MacKenzie, A R; Di Carlo, P; Di Marco, C F; Dorsey, J R; Evans, M; Fowler, D; Gallagher, M W; Hopkins, J R; Jones, C E; Langford, B; Lee, J D; Lewis, A C; Lim, S F; McQuaid, J; Misztal, P; Moller, S J; Monks, P S; Nemitz, E; Oram, D E; Owen, S M; Phillips, G J; Pugh, T A M; Pyle, J A; Reeves, C E; Ryder, J; Siong, J; Skiba, U; Stewart, D J

    2009-11-01

    More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly" fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O(3)), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O(3) concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O(3) concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.

  20. Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution

    PubMed Central

    Hewitt, C. N.; MacKenzie, A. R.; Di Carlo, P.; Di Marco, C. F.; Dorsey, J. R.; Evans, M.; Fowler, D.; Gallagher, M. W.; Hopkins, J. R.; Jones, C. E.; Langford, B.; Lee, J. D.; Lewis, A. C.; Lim, S. F.; McQuaid, J.; Misztal, P.; Moller, S. J.; Monks, P. S.; Nemitz, E.; Oram, D. E.; Owen, S. M.; Phillips, G. J.; Pugh, T. A. M.; Pyle, J. A.; Reeves, C. E.; Ryder, J.; Siong, J.; Skiba, U.; Stewart, D. J.

    2009-01-01

    More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an “environmentally friendly” fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O3 concentrations will reach 100 parts per billion (109) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided. PMID:19841269

  1. Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution

    NASA Astrophysics Data System (ADS)

    Hewitt, Nick; Lee, James

    2010-05-01

    More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an ‘‘environmentally friendly'' fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O3 concentrations will reach 100 parts per billion (109) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.

  2. The effect of ambient ozone pollution and acidic rain on the growth and chlorophyll content of green and white ash.

    PubMed

    Elliott, C L; Eberhardt, J C; Brennan, E G

    1987-01-01

    Two- and three-year old green ash (Fraxinus americana L.) and white ash (Fraxinus pennsylvanica Marsh.) seedlings were exposed to combinations of ambient ozone and acidic ambient rainfall in New Brunswick, New Jersey. During the 3-year study the potted seedlings did not develop typical foliar ozone toxicity symptoms, despite the occurrence of as many as 78 h in exceedance of the National Ambient Air Quality Standard of 0.12 ppm. Although the pH of the rainfall was as low as 3.6 and averaged 4.1, no symptoms were observed resulting from the ambient precipitation. The rate of shoot growth in terms of height and diameter was generally not affected by either of the pollutants during the growing season. Although the chlorophyll content of white ash foliage was low following frequent rainfall in the early summer of 1984, there was no statistically significant evidence that acid raid or ambient ozone decreased chlorophyll in ash seedlings during the 3-year study.

  3. Calculations of increased solar UV fluxes and DUV doses due to stratospheric-ozone depletions

    SciTech Connect

    Zardecki, A.; Gerstl, S.A.W.

    1982-02-01

    Accurate radiative transfer calculations are performed in the middle ultraviolet spectral region for aerosol-loaded atmospheres with the goal of determining the solar irradiance at the ground and quantifying the irradiance perturbations due to the presence of aerosols and various ozone depletions. The extent of the increase of UV-B radiation as a function of wave-length and solar zenith angle is calculated for five model atmospheres. In addition, the damaging ultraviolet dose rates and radiation amplification factors are evaluated at different latitudes and seasons for erythemal and DNA action spectra.

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

    SciTech Connect

    Lee, E.H. )

    1991-01-01

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

  5. Regional-scale transport of air pollutants: impacts of Southern California emissions on Phoenix ground-level ozone concentrations

    NASA Astrophysics Data System (ADS)

    Li, J.; Georgescu, M.; Hyde, P.; Mahalov, A.; Moustaoui, M.

    2015-08-01

    In this study, WRF-Chem is utilized at high resolution (1.333 km grid spacing for the innermost domain) to investigate impacts of southern California anthropogenic emissions (SoCal) on Phoenix ground-level ozone concentrations ([O3]) for a pair of recent exceedance episodes. First, WRF-Chem control simulations, based on the US Environmental Protection Agency (EPA) 2005 National Emissions Inventories (NEI05), are conducted to evaluate model performance. Compared with surface observations of hourly ozone, CO, NOX, and wind fields, the control simulations reproduce observed variability well. Simulated [O3] are comparable with the previous studies in this region. Next, the relative contribution of SoCal and Arizona local anthropogenic emissions (AZ) to ozone exceedances within the Phoenix metropolitan area is investigated via a trio of sensitivity simulations: (1) SoCal emissions are excluded, with all other emissions as in Control; (2) AZ emissions are excluded with all other emissions as in Control; and (3) SoCal and AZ emissions are excluded (i.e., all anthropogenic emissions are eliminated) to account only for Biogenic emissions and lateral boundary inflow (BILB). Based on the USEPA NEI05, results for the selected events indicate the impacts of AZ emissions are dominant on daily maximum 8 h average (DMA8) [O3] in Phoenix. SoCal contributions to DMA8 [O3] for the Phoenix metropolitan area range from a few ppbv to over 30 ppbv (10-30 % relative to Control experiments). [O3] from SoCal and AZ emissions exhibit the expected diurnal characteristics that are determined by physical and photochemical processes, while BILB contributions to DMA8 [O3] in Phoenix also play a key role. Finally, ozone transport processes and pathways within the lower troposphere are investigated. During daytime, pollutants (mainly ozone) near the Southern California coasts are pumped into the planetary boundary-layer over the Southern California desert through the mountain chimney and pass

  6. Regional-scale transport of air pollutants: impacts of southern California emissions on Phoenix ground-level ozone concentrations

    NASA Astrophysics Data System (ADS)

    Li, J.; Georgescu, M.; Hyde, P.; Mahalov, A.; Moustaoui, M.

    2015-03-01

    In this study, WRF-Chem is utilized at high-resolution (1.333 km grid spacing for the innermost domain) to investigate impacts of southern California anthropogenic emissions (SoCal) on Phoenix ground-level ozone concentrations ([O3]) for a pair of recent exceedance episodes. First, WRF-Chem Control simulations are conducted to evaluate model performance. Compared with surface observations of hourly ozone, CO, NOx, and wind fields, the Control simulations reproduce observed variability well. Simulated [O3] are within acceptance ranges recommended by the Environmental Protection Agency (EPA) that characterize skillful experiments. Next, the relative contribution of SoCal and Arizona local anthropogenic emissions (AZ) to ozone exceedance within the Phoenix metropolitan area is investigated via a trio of sensitivity simulations: (1) SoCal emissions are excluded, with all other emissions as in Control; (2) AZ emissions are excluded with all other emissions as in Control; and (3) SoCal and AZ emissions are excluded (i.e., all anthropogenic emissions are eliminated) to account only for biogenic emissions [BEO]. Results for the selected events indicate the impacts of AZ emissions are dominant on daily maximum 8 h average (DMA8) [O3] in Phoenix. SoCal contributions to DMA8 [O3] for the Phoenix metropolitan area range from a few ppbv to over 30 ppbv (10-30% relative to Control experiments). [O3] from SoCal and AZ emissions exhibit the expected diurnal characteristics that are determined by physical and photochemical processes, while BEO contributions to DMA8 [O3] in Phoenix also play a key role. Finally, ozone transport processes and pathways within the lower troposphere are investigated. During daytime, pollutants (mainly ozone) near the southern California coasts are pumped into the planetary boundary-layer over the southern California desert through the mountain chimney and pass channel effects, aiding eastward transport along the desert air basins in southern California

  7. Ozone air pollution and foliar injury development on native plants of Switzerland.

    PubMed

    Novak, Kristopher; Skelly, John M; Schaub, Marcus; Kräuchi, Norbert; Hug, Christian; Landolt, Werner; Bleuler, Peter

    2003-01-01

    The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using an open-top chamber research facility located within the Lattecaldo Cantonal Forest Nursery in Canton Ticino, southern Switzerland (600 m asl). Plants were examined daily and dates of initial foliar injury were recorded in order to determine the cumulative AOT40 ppb h ozone exposure required to cause visible foliar injury. Plant responses to ozone varied significantly among species; 11 species exhibited visible symptoms typical of exposures to ambient ozone. The symptomatic species (from most to least sensitive) were Populus nigra, Viburnum lantana, Salix alba, Crataegus monogyna, Viburnum opulus, Tilia platyphyllos, Cornus alba, Prunus avium, Fraxinus excelsior, Ribes alpinum, and Tilia cordata; Clematis spp. did not show foliar symptoms. Of the 11 symptomatic species, five showed initial injury below the critical level AOT40 10 ppmh O3 in the 2001 season.

  8. Projected changes in high ozone pollution events over the Eastern United States over the 21st century

    NASA Astrophysics Data System (ADS)

    Fiore, A. M.; Rieder, H.; Horowitz, L. W.; Naik, V.

    2013-12-01

    Over the past few decades, thresholds for the United States (US) National Ambient Air Quality Standard (NAAQS) for ozone (O3), established to protect public health and welfare, have been lowered repeatedly. We recently applied methods from extreme value theory (EVT) to maximum daily 8-hour average ozone (MDA8 O3) observed by the Clean Air Status and Trends Network (CASTNet) to quantify the significant decline in both frequency and magnitude of high O3 pollution events over the Eastern US from 1988 to 2009. These improvements to Eastern US air quality have been reported in prior studies and result from changes in air quality regulations and subsequent control measures (e.g., the 'NOx SIP Call') as demonstrated by our analysis of 1-year and 5-year return levels. Here we extend this analysis to future projections of high O3 pollution events spanning the course of the 21st century. To this aim, we analyze simulations from the GFDL CM3 chemistry-climate model under selected Representative Concentration Pathway (RCP) scenarios: RCP4.5 and RCP8.5 (representing a moderate and strong climate warming with a global mean temperature change by 2100 compared to present day of +2.3K and +4.5K, respectively). Under both scenarios, NOx emissions decrease by ~80% over North America by 2100 under the assumption of aggressive ozone pollution controls. A third scenario, termed RCP4.5_WMGG, in which well-mixed greenhouse gases follow the RCP4.5 scenario but O3 and aerosol precursor emissions are held at 2005 levels, enables us to isolate the role of climate change from that of emission reductions. As we find a positive bias in GFDL CM3 MDA8 O3 compared to the Eastern US CASTNet O3 measurements during summer (a common feature in the current generation of models), we develop a correction method based on quantile-mapping. This bias correction effectively removes the model bias while preserving the temporal changes in MDA8 O3 as simulated under different RCPs over the course of the 21st

  9. Projected changes in high ozone pollution events over the Eastern United States over the 21st century

    NASA Astrophysics Data System (ADS)

    Rieder, Harald E.; Fiore, Arlene M.; Horrowitz, Larry W.; Naik, Vaishali

    2014-05-01

    Over the past few decades, thresholds for the United States (US) National Ambient Air Quality Standard (NAAQS) for ozone (O3), established to protect public health and welfare, have been lowered repeatedly. We recently applied methods from extreme value theory (EVT) to maximum daily 8-hour average ozone (MDA8 O3) observed by the Clean Air Status and Trends Network (CASTNet) to quantify the significant decline in both frequency and magnitude of high O3 pollution events over the Eastern US from 1988 to 2009. These improvements to Eastern US air quality have been reported in prior studies and result from changes in air quality regulations and subsequent control measures (e.g., the "NOx SIP Call") as demonstrated by our analysis of 1-year and 5-year return levels. Here we extend this analysis to future projections of high O3 pollution events spanning the course of the 21st century. To this aim, we analyze simulations from the GFDL CM3 chemistry-climate model under selected Representative Concentration Pathway (RCP) scenarios: RCP4.5 and RCP8.5 (representing a moderate and strong climate warming with a global mean temperature change by 2100 compared to present day of +2.3K and +4.5K, respectively). Under both scenarios, NOx emissions decrease by ~80% over North America by 2100 under the assumption of aggressive ozone pollution controls. A third scenario, termed RCP4.5_WMGG, in which well-mixed greenhouse gases follow the RCP4.5 scenario but O3 and aerosol precursor emissions are held at 2005 levels, enables us to isolate the role of climate change from that of emission reductions. As we find a positive bias in GFDL CM3 MDA8 O3 compared to the Eastern US CASTNet O3 measurements during summer (a common feature in the current generation of models), we develop a correction method based on quantile-mapping. This bias correction effectively removes the model bias while preserving the temporal changes in MDA8 O3 as simulated under different RCPs over the course of the 21st

  10. Impact of local and non-local sources of pollution on background US Ozone: synergy of a low-earth orbiting and geostationary sounder constellation

    NASA Astrophysics Data System (ADS)

    Bowman, K. W.; Lee, M.

    2015-12-01

    Dramatic changes in the global distribution of emissions over the last decade have fundamentally altered source-receptor pollution impacts. A new generation of low-earth orbiting (LEO) sounders complimented by geostationary sounders over North America, Europe, and Asia providing a unique opportunity to quantify the current and future trajectory of emissions and their impact on global pollution. We examine the potential of this constellation of air quality sounders to quantify the role of local and non-local sources of pollution on background ozone in the US. Based upon an adjoint sensitivity method, we quantify the role synoptic scale transport of non-US pollution on US background ozone over months representative of different source-receptor relationships. This analysis allows us distinguish emission trajectories from megacities, e.g. Beijing, or regions, e.g., western China, from natural trends on downwind ozone. We subsequently explore how a combination of LEO and GEO observations could help quantify the balance of local emissions against changes in distant sources . These results show how this unprecedented new international ozone observing system can monitor the changing structure of emissions and their impact on global pollution.

  11. Remediation of groundwater polluted with chlorinated ethylenes by ozone-electron beam irradiation treatment.

    PubMed

    Gehringer, P; Proksch, E; Eschweiler, H; Szinovatz, W

    1992-09-01

    OH radicals formed in water radiolysis may be effectively used for the oxidative decomposition of trichloroethylene and perchloroethylene contained as micropollutants in groundwater. Addition of ozone to the water before irradiation causes the reducing species of the water radiolysis to be converted into OH radicals. Moreover, this eliminates the dose rate effect observed with irradiation alone. By the ozone-electron beam treatment greater than 95% of the organic chlorine content are mineralized, only negligible amounts of organic chlorine containing by-products are formed. AMES test has shown no mutagenic activity at all.

  12. Intercontinental Transport of Air Pollution

    NASA Technical Reports Server (NTRS)

    Rogers, David; Whung, Pai-Yei; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The development of the global economy goes beyond raising our standards of living. We are in an ear of increasing environmental as well as economic interdependence. Long-range transport of anthropogenic atmospheric pollutants such as ozone, ozone precursors, airborne particles, heavy metals (such as mercury) and persistent organic pollutants are the four major types of pollution that are transported over intercontinental distances and have global environmental effects. The talk includes: 1) an overview of the international agreements related to intercontinental transport of air pollutants, 2) information needed for decision making, 3) overview of the past research on intercontinental transport of air pollutants - a North American's perspective, and 4) future research needs.

  13. Simulated stratospheric ozone depletion and increased ultraviolet radiation: effects on photocarcinogenesis in hairless mice.

    PubMed

    Forbes, P D; Davies, R E; Urbach, F; Berger, D; Cole, C

    1982-07-01

    Solar ultraviolet radiation at the surface of the earth is a recognized cause of skin cancer. Postulated anthropogenic reductions in the thickness of the ozone layer would lead to an increased amount of ultraviolet radiation and hence would be expected to increase the risk of skin carcinogenesis. This study uses hairless (Skh:HR) mice as an animal model to study this increased risk. The mice were exposed 5 days/week to graded doses of ultraviolet radiation from a xenon arc lamp attenuated by five different thicknesses of Schott glass filters (WG320) to simulate various ozone layer thicknesses. A Robertson-Berger sunburning ultraviolet meter was used as one of the forms of dosimetry. The results of the various exposure treatments are expressed as the percentage of animal with tumors (incidence) versus time after commencing irradiation and as cumulative tumor yield (average number of tumors per survivor) versus time. With any given filter, the time to 50% incidence is inversely related to daily dose in Robertson-Berger meter units. The time to 50% incidence for comparable Robertson-Berger meter doses through different filter thicknesses increases with increasing thickness. These results indicate that the effective dose for skin cancer induction may be estimated from the Robertson-Berger meter dose but that the Robertson-Berger meter response spectrum underestimates the photocarcinogenic effectiveness of the shorter wavelengths. The cumulative tumor yield data are also consistent with these conclusions. Alternate weighting of the source spectra with the acute-response action spectrum for mouse skin edema gave a better correlation between unit dose and time to a tumor response, independent of the source spectral distribution. This suggests that the mouse skin edema action spectrum, indistinguishable from a human skin erythema action spectrum for lambda greater than 295 nm, is similar in shape to the mouse skin photocarcinogenesis action spectrum for lambda greater than

  14. Association between long-term air pollution and increased blood pressure and hypertension in China.

    PubMed

    Dong, Guang-Hui; Qian, Zhengmin Min; Xaverius, Pamela K; Trevathan, Edwin; Maalouf, Salwa; Parker, Jamaal; Yang, Laiji; Liu, Miao-Miao; Wang, Da; Ren, Wan-Hui; Ma, Wenjun; Wang, Jing; Zelicoff, Alan; Fu, Qiang; Simckes, Maayan

    2013-03-01

    Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ≤10 µm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxides (NO(2)), and ozone (O(3)) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08-1.16) per 19 μg/m(3) increase in PM(10), 1.11 (95% CI, 1.04-1.18) per 20 μg/m(3) increase in SO(2), and 1.13 (95% CI, 1.06-1.20) per 22 μg/m(3) increase in O(3). The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48-1.27) and 0.32 mm Hg (95% CI, 0.08-0.56) per 19 μg/m(3) interquartile increase in PM(10), 0.80 mm Hg (95% CI, 0.46-1.14) and 0.31 mm Hg (95% CI, 0.10-0.51) per 20 μg/m(3) interquartile increase in SO(2), and 0.73 mm Hg (95% CI, 0.35-1.11) and 0.37 mm Hg (95% CI, 0.14-0.61) per 22 μg/m(3) interquartile increase in O(3). These associations were only statistically significant in men. In conclusion, long-term exposure to PM(10), SO(2), and O(3) was associated with increased arterial blood pressure and hypertension in the study population.

  15. Surface Ozone Background in the United States: Canadian and Mexican Pollution Influences

    EPA Science Inventory

    We use a global chemical transport model (GEOS-Chem) with 1° x 1° horizontal resolution to quantify the effects of anthropogenic emissions from Canada, Mexico, and outside North America on daily maximum 8-h average ozone concentrations in U.S.surface air.

  16. Development of pollution reduction strategies for Mexico City: Estimating cost and ozone reduction effectiveness

    SciTech Connect

    Thayer, G.R.; Hardie, R.W.; Barrera-Roldan, A.

    1993-12-31

    This reports on the collection and preparation of data (costs and air quality improvement) for the strategic evaluation portion of the Mexico City Air Quality Research Initiative (MARI). Reports written for the Mexico City government by various international organizations were used to identify proposed options along with estimates of cost and emission reductions. Information from appropriate options identified by SCAQMD for Southem California were also used in the analysis. A linear optimization method was used to select a group of options or a strategy to be evaluated by decision analysis. However, the reduction of ozone levels is not a linear function of the reduction of hydrocarbon and NO{sub x} emissions. Therefore, a more detailed analysis was required for ozone. An equation for a plane on an isopleth calculated with a trajectory model was obtained using two endpoints that bracket the expected total ozone precursor reductions plus the starting concentrations for hydrocarbons and NO{sub x}. The relationship between ozone levels and the hydrocarbon and NO{sub x} concentrations was assumed to lie on this plane. This relationship was used in the linear optimization program to select the options comprising a strategy.

  17. Effect of noise in principal component analysis with an application to ozone pollution

    NASA Astrophysics Data System (ADS)

    Tsakiri, Katerina G.

    This thesis analyzes the effect of independent noise in principal components of k normally distributed random variables defined by a covariance matrix. We prove that the principal components as well as the canonical variate pairs determined from joint distribution of original sample affected by noise can be essentially different in comparison with those determined from the original sample. However when the differences between the eigenvalues of the original covariance matrix are sufficiently large compared to the level of the noise, the effect of noise in principal components and canonical variate pairs proved to be negligible. The theoretical results are supported by simulation study and examples. Moreover, we compare our results about the eigenvalues and eigenvectors in the two dimensional case with other models examined before. This theory can be applied in any field for the decomposition of the components in multivariate analysis. One application is the detection and prediction of the main atmospheric factor of ozone concentrations on the example of Albany, New York. Using daily ozone, solar radiation, temperature, wind speed and precipitation data, we determine the main atmospheric factor for the explanation and prediction of ozone concentrations. A methodology is described for the decomposition of the time series of ozone and other atmospheric variables into the global term component which describes the long term trend and the seasonal variations, and the synoptic scale component which describes the short term variations. By using the Canonical Correlation Analysis, we show that solar radiation is the only main factor between the atmospheric variables considered here for the explanation and prediction of the global and synoptic scale component of ozone. The global term components are modeled by a linear regression model, while the synoptic scale components by a vector autoregressive model and the Kalman filter. The coefficient of determination, R2, for the

  18. Co-exposure to ultrafine particulate matter and ozone causes electrocardiogram changes indicative of increased arrhythmia risk in mice

    EPA Science Inventory

    Numerous studies have shown a relationship between acute air pollution exposure and increased risk for cardiovascular morbidity and mortality. Due to the inherent complexity of air pollution, recent studies have focused on co-exposures to better understand potential interactions....

  19. Regional ozone impacts of increased natural gas use in the Texas power sector and development in the Eagle Ford shale.

    PubMed

    Pacsi, Adam P; Kimura, Yosuke; McGaughey, Gary; McDonald-Buller, Elena C; Allen, David T

    2015-03-17

    The combined emissions and air quality impacts of electricity generation in the Texas grid and natural gas production in the Eagle Ford shale were estimated at various natural gas price points for the power sector. The increased use of natural gas in the power sector, in place of coal-fired power generation, drove reductions in average daily maximum 8 h ozone concentration of 0.6-1.3 ppb in northeastern Texas for a high ozone episode used in air quality planning. The associated increase in Eagle Ford upstream oil and gas production nitrogen oxide (NOx) emissions caused an estimated local increase, in south Texas, of 0.3-0.7 ppb in the same ozone metric. In addition, the potential ozone impacts of Eagle Ford emissions on nearby urban areas were estimated. On the basis of evidence from this work and a previous study on the Barnett shale, the combined ozone impact of increased natural gas development and use in the power sector is likely to vary regionally and must be analyzed on a case by case basis.

  20. Regional ozone impacts of increased natural gas use in the Texas power sector and development in the Eagle Ford shale.

    PubMed

    Pacsi, Adam P; Kimura, Yosuke; McGaughey, Gary; McDonald-Buller, Elena C; Allen, David T

    2015-03-17

    The combined emissions and air quality impacts of electricity generation in the Texas grid and natural gas production in the Eagle Ford shale were estimated at various natural gas price points for the power sector. The increased use of natural gas in the power sector, in place of coal-fired power generation, drove reductions in average daily maximum 8 h ozone concentration of 0.6-1.3 ppb in northeastern Texas for a high ozone episode used in air quality planning. The associated increase in Eagle Ford upstream oil and gas production nitrogen oxide (NOx) emissions caused an estimated local increase, in south Texas, of 0.3-0.7 ppb in the same ozone metric. In addition, the potential ozone impacts of Eagle Ford emissions on nearby urban areas were estimated. On the basis of evidence from this work and a previous study on the Barnett shale, the combined ozone impact of increased natural gas development and use in the power sector is likely to vary regionally and must be analyzed on a case by case basis. PMID:25723953

  1. Changes in the frequency and return level of high ozone pollution events over the eastern United States following emission controls

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Fiore, A. M.; Polvani, L. M.; Lamarque, J.-F.; Fang, Y.

    2013-03-01

    In order to quantify the impact of recent efforts to abate surface ozone (O3) pollution, we analyze changes in the frequency and return level of summertime (JJA) high surface O3 events over the eastern United States (US) from 1988-1998 to 1999-2009. We apply methods from extreme value theory (EVT) to maximum daily 8-hour average ozone (MDA8 O3) observed by the Clean Air Status and Trends Network (CASTNet) and define O3 extremes as days on which MDA8 O3 exceeds a threshold of 75 ppb (MDA8 O3>75). Over the eastern US, we find that the number of summer days with MDA8 O3>75 declined on average by about a factor of two from 1988-1998 to 1999-2009. The applied generalized Pareto distribution (GPD) fits the high tail of MDA8 O3 much better than a Gaussian distribution and enables the derivation of probabilistic return levels (describing the probability of exceeding a value x within a time window T) for high O3 pollution events. This new approach confirms the significant decline in both frequency and magnitude of high O3 pollution events over the eastern US during recent years reported in prior studies. Our analysis of 1-yr and 5-yr return levels at each station demonstrates the strong impact of changes in air quality regulations and subsequent control measures (e.g., the ‘NOx SIP Call’), as the 5-yr return levels of the period 1999-2009 correspond roughly to the 1-yr return levels of the earlier time period (1988-1998). Regionally, the return levels dropped between 1988-1998 and 1999-2009 by about 8 ppb in the Mid-Atlantic (MA) and Great Lakes (GL) regions, while the strongest decline, about 13 ppb, is observed in the Northeast (NE) region. Nearly all stations (21 out of 23) have 1-yr return levels well below 100 ppb and 5-yr return levels well below 110 ppb in 1999-2009. Decreases in eastern US O3 pollution are largest after full implementation of the nitrogen oxide (NOx) reductions under the ‘NOx SIP Call’. We conclude that the application of EVT methods

  2. Understanding high wintertime ozone pollution events in an oil and natural gas producing region of the western US

    NASA Astrophysics Data System (ADS)

    Ahmadov, R.; McKeen, S.; Trainer, M.; Banta, R.; Brewer, A.; Brown, S.; Edwards, P. M.; de Gouw, J. A.; Frost, G. J.; Gilman, J.; Helmig, D.; Johnson, B.; Karion, A.; Koss, A.; Langford, A.; Lerner, B.; Olson, J.; Oltmans, S.; Peischl, J.; Pétron, G.; Pichugina, Y.; Roberts, J. M.; Ryerson, T.; Schnell, R.; Senff, C.; Sweeney, C.; Thompson, C.; Veres, P.; Warneke, C.; Wild, R.; Williams, E. J.; Yuan, B.; Zamora, R.

    2014-08-01

    Recent increases in oil and natural gas (NG) production throughout the western US have come with scientific and public interest in emission rates, air quality and climate impacts related to this industry. This study uses a regional scale air quality model WRF-Chem to simulate high ozone (O3) episodes during the winter of 2013 over the Uinta Basin (UB) in northeastern Utah, which is densely populated by thousands of oil and NG wells. The high resolution meteorological simulations are able to qualitatively reproduce the wintertime cold pool conditions that occurred in 2013, allowing the model to reproduce the observed multi-day buildup of atmospheric pollutants and accompanying rapid photochemical ozone formation in the UB. Two different emission scenarios for the oil and NG sector were employed in this study. The first emission scenario (bottom-up) was based on the US EPA National Emission Inventory (NEI) (2011, version 1) for the oil and NG sector for the UB. The second emission scenario (top-down) was based on the previously derived estimates of methane (CH4) emissions and a regression analysis for multiple species relative to CH4 concentration measurements in the UB. WRF-Chem simulations using the two emission data sets resulted in significant differences for concentrations of most gas-phase species. Evaluation of the model results shows greater underestimates of CH4 and other volatile organic compounds (VOCs) in the simulation with the NEI-2011 inventory than the case when the top-down emission scenario was used. Unlike VOCs, the NEI-2011 inventory significantly overestimates the emissions of nitrogen oxides (NOx), while the top-down emission scenario results in a moderate negative bias. Comparison of simulations using the two emission data sets reveals that the top-down case captures the high O3 episodes. In contrast, the simulation case using the bottom-up inventory is not able to reproduce any of the observed high O3 concentrations in the UB. A sensitivity

  3. Effect of climate change on surface ozone over North America, Europe, and East Asia

    NASA Astrophysics Data System (ADS)

    Schnell, Jordan L.; Prather, Michael J.; Josse, Beatrice; Naik, Vaishali; Horowitz, Larry W.; Zeng, Guang; Shindell, Drew T.; Faluvegi, Greg

    2016-04-01

    The effect of future climate change on surface ozone over North America, Europe, and East Asia is evaluated using present-day (2000s) and future (2100s) hourly surface ozone simulated by four global models. Future climate follows RCP8.5, while methane and anthropogenic ozone precursors are fixed at year 2000 levels. Climate change shifts the seasonal surface ozone peak to earlier in the year and increases the amplitude of the annual cycle. Increases in mean summertime and high-percentile ozone are generally found in polluted environments, while decreases are found in clean environments. We propose that climate change augments the efficiency of precursor emissions to generate surface ozone in polluted regions, thus reducing precursor export to neighboring downwind locations. Even with constant biogenic emissions, climate change causes the largest ozone increases at high percentiles. In most cases, air quality extreme episodes become larger and contain higher ozone levels relative to the rest of the distribution.

  4. NO3 radical measurements in a polluted marine environment: links to ozone formation

    NASA Astrophysics Data System (ADS)

    McLaren, R.; Wojtal, P.; Majonis, D.; McCourt, J.; Halla, J. D.; Brook, J.

    2010-05-01

    Nighttime chemistry in polluted regions is dominated by the nitrate radical (NO3) including its direct reaction with natural and anthropogenic hydrocarbons, its reaction with NO2 to form N2O5, and subsequent reactions of N2O5 to form HNO3 and chlorine containing photolabile species. We report nighttime measurements of NO3, NO2, and O3, in the polluted marine boundary layer southwest of Vancouver, BC during a three week study in the summer of 2005. The concentration of N2O5 was calculated using the well known equilibrium, NO3+NO2↔N2O5. Median overnight mixing ratios of NO3, N2O5 and NO2 were 10.3 ppt, 122 ppt and 8.3 ppb with median N2O5/NO3 molar ratios of 13.1 and median nocturnal partitioning of 4.9%. Due to the high levels of NO2 that can inhibit approach to steady-state, we use a method for calculating NO3 lifetimes that does not assume the steady-state approximation. Median and average lifetimes of NO3 in the NO3-N2O5 nighttime reservoir were 1.1-2.3 min. We have determined nocturnal profiles of the pseudo first order loss coefficient of NO3 and the first order loss coefficients of N2O5 by regression of the NO3 inverse lifetimes with the [N2O5]/[NO3] ratio. Direct losses of NO3 are highest early in the night, tapering off as the night proceeds. The magnitude of the first order loss coefficient of N2O5 is consistent with, but not verification of, recommended homogeneous rate coefficients for reaction of N2O5 with water vapor early in the night, but increases significantly in the latter part of the night when relative humidity increases beyond 75%, consistent with heterogeneous reactions of N2O5 with aerosols with a rate constant khet=(1.2±0.4)×10-3 s-1-(1.6±0.4)×10-3 s-1. Analysis indicates that a correlation exists between overnight integrated N2O5 concentrations in the marine boundary layer, a surrogate for the accumulation of chlorine containing photolabile species, and maximum 1-h average O3 at stations in the Lower Fraser Valley the next day when

  5. NO3 radical measurements in a polluted marine environment: links to ozone formation

    NASA Astrophysics Data System (ADS)

    McLaren, R.; Wojtal, P.; Majonis, D.; McCourt, J.; Halla, J. D.; Brook, J.

    2009-11-01

    Nighttime chemistry in polluted regions is dominated by the nitrate radical (NO3) including its direct reaction with natural and anthropogenic hydrocarbons, its reaction with NO2 to form N2O5, and subsequent reactions of N2O5 to form HNO3 and chlorine containing photolabile species. We report nighttime measurements of NO3, NO2, and O3, in the polluted marine boundary layer southwest of Vancouver, BC during a three week study in summer of 2005. The concentration of N2O5 was calculated using the well known equilibrium, NO3+NO2↔N2O5. Median overnight mixing ratios of NO3, N2O5 and NO2 were 10.3 ppt, 122 ppt and 8.3 ppb with median N2O5/NO3 molar ratios of 13.1 and median nocturnal partitioning of 4.9%. Due to the high levels of NO2 that can inhibit approach to steady-state, we use a method for calculating NO3 lifetimes that does not assume the steady-state approximation. Median and average lifetimes of NO3 in the NO3-N2O5 nighttime reservoir were 1.1-2.3 min. We have determined nocturnal profiles of the pseudo first order loss coefficient of NO3 and the first order loss coefficients of N2O5 by regression of the NO3 inverse lifetimes with the [N2O5]/[NO3] ratio. Direct losses of NO3 are highest early in the night, tapering off as the night proceeds. The magnitude of the first order loss coefficient of N2O5 is consistent with recommended homogeneous rate coefficients for reaction of N2O5 with water vapor early in the night, but increases significantly in the latter part of the night when relative humidity increases beyond 75%, consistent with heterogeneous reactions of N2O5 with sea salt and/or other aerosols with rate constant khet=1.2×10-3 s-1. Analysis indicates that a correlation exists between overnight integrated N2O5 concentrations in the marine boundary layer, a surrogate for the accumulation of chlorine containing photolabile species, and maximum 1-h average O3 at stations in the Lower Fraser Valley the next day when there is clear evidence of a sea

  6. Effect of water vapor on the destruction of ozone in the stratosphere perturbed by ClX or NOx pollutants

    NASA Technical Reports Server (NTRS)

    Liu, S. C.; Donahue, T. M.; Cicerone, R. J.; Chameides, W. L.

    1976-01-01

    Results are presented for a self-consistent one-dimensional coupled flow calculation for Ox, NOx, HOx, ClX, H2O, H2, CH4, H2O2, and N2O densities between 10 and 120 km. The results agree well with observations for the normal midlatitude atmosphere over this altitude range. ClX, NOx, and H2O are varied independently in the model considered. It is shown that the effect of depletion of ozone by ClX is to remove ozone preferentially above 30 km and to lower the altitude of maximum ozone density. This leads to enhanced solar heating of the lower stratosphere and tropopause and suggests the possibility of an increased flux of water into the stratosphere. Increasing water vapor in the stratosphere greatly enhances the rate of destruction of O3 by ClX and also causes an increase in the rate of destruction of O3 in the NOx-perturbed atmosphere.

  7. Increase of exhaled nitric oxide in children exposed to low levels of ambient ozone.

    PubMed

    Nickmilder, Marc; de Burbure, Claire; Carbonnelle, Sylviane; Sylviane, Carbonnelle; Dumont, Xavier; Xavier, Dumont; Bernard, Alfred; Alfred, Bernard; Derouane, Alain; Alain, Derouane

    2007-02-01

    Ozone (O3) is known to induce lung function impairment and airways inflammation during episodes of photochemical smog. The aim of the present study was to assess the inflammatory effect of ambient O3 in healthy children using nitric oxide in exhaled air (eNO) as a noninvasive test. The study was performed on 6 groups of children (n = 11-15), aged 6.5 to 15 yr, who attended summer camps in rural areas of the south of Belgium in 2002. Ambient O3 concentrations continuously monitored in the camps ranged from 48 to 221 microg/m3 (1-h maximal concentration). Children remained outdoors during the experimental days, doing various recreational activities but no sports. Lung function tests (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) and eNO were measured twice in each child in the morning and in the evening. While lung function tests did not show any consistent pattern of decrease at these O3 levels, a highly significant increase in eNO was found in all subjects from an ambient 1-h O3 level of 167 microg/m3. A multivariate analysis did not reveal any influence of age, gender, height, weight, and body mass index (BMI) of the children. The threshold for this O3-induced increase in eNO estimated benchmark dose analysis was 135 microg/m3 for 1-h exposure and 110 microg/m3 for 8-h exposure. These observations suggest that ambient ozone produces early inflammatory changes in the airways of children at levels slightly below current air quality standards. PMID:17365589

  8. Does toxicity of aromatic pollutants increase under remote atmospheric conditions?

    PubMed Central

    Kroflič, Ana; Grilc, Miha; Grgić, Irena

    2015-01-01

    Aromatic compounds contribute significantly to the budget of atmospheric pollutants and represent considerable hazard to living organisms. However, they are only rarely included into atmospheric models which deviate substantially from field measurements. A powerful experimental-simulation tool for the assessment of the impact of low- and semi-volatile aromatic pollutants on the environment due to their atmospheric aqueous phase aging has been developed and introduced for the first time. The case study herein reveals that remote biotopes might be the most damaged by wet urban guaiacol-containing biomass burning aerosols. It is shown that only after the primary pollutant guaiacol has been consumed, its probably most toxic nitroaromatic product is largely formed. Revising the recent understanding of atmospheric aqueous phase chemistry, which is mostly concerned with the radical nitration mechanisms, the observed phenomenon is mainly attributed to the electrophilic nitrogen-containing reactive species. Here, their intriguing role is closely inspected and discussed from the ecological perspective. PMID:25748923

  9. Age, Strain, and Gender as Factors for Increased Sensitivity of the Mouse Lung to Inhaled Ozone

    PubMed Central

    Vancza, Elizabeth M.; Galdanes, Karen; Gunnison, Al; Hatch, Gary; Gordon, Terry

    2009-01-01

    Ozone (O3) is a respiratory irritant that leads to airway inflammation and pulmonary dysfunction. Animal studies show that neonates are more sensitive to O3 inhalation than adults, and children represent a potentially susceptible population. This latter notion is not well established, and biological mechanisms underlying a predisposition to pollution-induced pulmonary effects are unknown. We examined age and strain as interactive factors affecting differential pulmonary responses to inhaled O3. Male and female adult mice (15 weeks old) and neonates (15–16 days old) from eight genetically diverse inbred strains were exposed to 0.8 ppm O3 for 5 h. Pulmonary injury and lung inflammation were quantified as total protein concentration and total polymorphonuclear neutrophil (PMN) number in lavage fluid recovered 24-h postexposure. Dose-response and time-course curves were generated using SJL/J pups, and 18O lung burden dose was assessed in additional mice. Interstrain differences in response to O3 were seen in neonatal mice: Balb/cJ and SJL/J being most sensitive and A/J and 129x1/SvJ most resistant. The PMN response to O3 was greater in neonates than in adults, specifically for SJL/J and C3H/HeJ strains, independent of dose. Small gender differences were also observed in adult mice. Variation in protein concentrations and PMN counts between adults and pups were strain dependent, suggesting that genetic determinants do play a role in age-related sensitivity to O3. Further research will help to determine what genetic factors contribute to these heightened responses, and to quantify the relative contribution of genes vs. environment in O3-induced health effects. PMID:19066396

  10. A model investigation of the impact of increases in anthropogenic NOx emissions between 1967 and 1980 on tropospheric ozone

    NASA Technical Reports Server (NTRS)

    Dignon, J.; Hameed, S.

    1985-01-01

    The impact of anthropogenic NOx emission on tropospheric ozone has been investigated. Two statistical models were used for estimating annual global emissions of NOx and for driving the trend in the emission for the years 1966-1980. Both models show a steady increase in the NOx emission, except for two brief periods of leveling off: after 1973 and after 1978. The impact was estimated by calculating the rates of emissions as functions of latitude, longitude, and year, with a one-dimensional (latitudinal) model, which included coupled tropospheric photochemistry and diffusive meridional transport. Steady-state photochemical calculations with prescribed NOx emissions appropriate for 1966 and 1980 indicate an ozone increase of 8-11 percent in the Northern Hemisphere, a result compatible with the rise in ozone suggested by the observations.

  11. Tropospheric Ozone and Photochemical Smog

    NASA Astrophysics Data System (ADS)

    Sillman, S.

    2003-12-01

    The question of air quality in polluted regions represents one of the issues of geochemistry with direct implications for human well-being. Human health and well-being, along with the well-being of plants, animals, and agricultural crops, are dependent on the quality of air we breathe. Since the start of the industrial era, air quality has become a matter of major importance, especially in large cities or urbanized regions with heavy automobile traffic and industrial activity.Concern over air quality existed as far back as the 1600s. Originally, polluted air in cities resulted from the burning of wood or coal, largely as a source of heat. The industrial revolution in England saw a great increase in the use of coal in rapidly growing cities, both for industrial use and domestic heating. London suffered from devastating pollution events during the late 1800s and early 1900s, with thousands of excess deaths attributed to air pollution (Brimblecombe, 1987). With increasing use of coal, other instances also occurred in continental Europe and the USA. These events were caused by directly emitted pollutants (primary pollutants), including sulfur dioxide (SO2), carbon monoxide (CO), and particulates. They were especially acute in cities with northerly locations during fall and winter when sunlight is at a minimum. These original pollution events gave rise to the term "smog" (a combination of smoke and fog). Events of this type have become much less severe since the 1950s in Western Europe and the US, as natural gas replaced coal as the primary source of home heating, industrial smokestacks were designed to emit at higher altitudes (where dispersion is more rapid), and industries were required to install pollution control equipment.Beginning in the 1950s, a new type of pollution, photochemical smog, became a major concern. Photochemical smog consists of ozone (O3) and other closely related species ("secondary pollutants") that are produced photochemically from directly

  12. Ground-level ozone in China: distribution and effects on crop yields.

    PubMed

    Wang, Xiaoke; Manning, William; Feng, Zongwei; Zhu, Yongguan

    2007-05-01

    Rapid economic development and an increasing demand for food in China have drawn attention to the role of ozone at pollution levels on crop yields. Some assessments of ozone effects on crop yields have been carried out in China. Determination of ozone distribution by geographical location and resulting crop loss estimations have been made by Chinese investigators and others from abroad. It is evident that surface level ozone levels in China exceed critical levels for occurrence of crop losses. Current levels of information from ozone dose/response studies are limited. Given the size of China, existing ozone monitoring sites are too few to provide enough data to scale ozone distribution to a national level. There are large uncertainties in the database for ozone effects on crop loss and for ozone distribution. Considerable research needs to be done to allow accurate estimation of crop losses caused by ozone in China. PMID:16973249

  13. Spatial pattern of ozone injury in Aleppo pine related to air pollution dynamics in a coastal-mountain region of eastern Spain.

    PubMed

    Sanz, M J; Calatayud, V; Calvo, E

    2000-05-01

    In eastern Spain, studies combining the tracking and meso-scale circulations of air pollutants with the evaluation of their effects on plants have been undertaken since 1994. Meso-scale processes are very important from the point of view of how and where forest ecosystems are affected by point sources and regional air pollution in the Mediterranean area. The first results of these field surveys show that in 1994, 1995 and 1996, the distribution pattern of ozone visual injury (chlorotic mottle) in Pinus halepensis correlated with the penetration of pollutants transported by the sea-breeze into coastal valleys of Castellón (eastern Spain). In this tree species, longer needles are associated with higher chlorotic mottle, and ozone injury seems to be among the factors affecting needle retention and crown transparency.

  14. Spatial Variability in Ozone and CO2 Flux during the Front Range Air Pollution and Photochemistry Experiment

    NASA Astrophysics Data System (ADS)

    Almand-Hunter, B.; Piedrahita, R.; Kaushik, A.; Noone, D. C.; Walker, J. T.; Hannigan, M.

    2014-12-01

    Air quality problems persist in the Northern Front-Range Metropolitan Area (NFRMA) of Colorado despite efforts to reduce emissions, and summertime ozone concentrations frequently exceed the NAAQS. Atmospheric modeling in the NFRMA is challenging due to the complex topography of the area, as well as diversity of pollutant sources (urban NOx and VOCs, power plants, oil and gas, agricultural emissions, biogenic emissions, and wildfires). An improved understanding of the local atmospheric chemistry will enable researchers to advance atmospheric models, which will subsequently be used to develop and test more effective air quality management strategies. The Front Range Air Pollution and Photochemistry Experiment (FRAPPE) investigates this problem through detailed examination of atmospheric chemistry in the NFRMA. Our project specifically explores the spatial variability in ozone (O3) concentration and dry deposition within the FRAPPE study area. One source of uncertainty in atmospheric models is O3 flux, which varies spatially due to local meteorology and variation in ambient concentration and deposition velocity. Model grid cells typically range in size from 10-100 km and 100-500 km, for regional and global models, respectively, and accurate representations of an entire grid cell cannot always be achieved. Large spatial variability within a model grid cell can lead to poor estimates of trace-gas flux and concentration. Our research addresses this issue by measuring spatial variability in O3 flux using low-cost dry-deposition flux chambers. We are measuring O3 and CO2 flux with 5 low-cost flux chambers and one eddy-covariance tower. The eddy-covariance tower is located at the Boulder Atmospheric Observatory in Erie, CO. All 5 chambers are within a 8.3 x 6 km square, with one chamber collocated with the eddy-covariance tower, and the other 4 chambers at distances of 0.33, 1.14, 3.22, and 7.55 km from the tower. The largest distance between any two chambers is 8.5 km. All

  15. Does Pollution Increase School Absences? NBER Working Paper No. 13252

    ERIC Educational Resources Information Center

    Currie, Janet; Hanushek, Eric; Kahn, E. Megan; Neidell, Matthew; Rivkin, Steven

    2007-01-01

    We examine the effect of air pollution on school absences using unique administrative data for elementary and middle school children in the 39 largest school districts in Texas. These data are merged with information from monitors maintained by the Environmental Protection Agency. To control for potentially confounding factors, we adopt a…

  16. 40 CFR 125.67 - Increase in effluent volume or amount of pollutants discharged.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of pollutants discharged. 125.67 Section 125.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION... discharge may result in any new or substantially increased discharges of the pollutant to which...

  17. 40 CFR 125.67 - Increase in effluent volume or amount of pollutants discharged.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of pollutants discharged. 125.67 Section 125.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION... discharge may result in any new or substantially increased discharges of the pollutant to which...

  18. 40 CFR 125.67 - Increase in effluent volume or amount of pollutants discharged.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of pollutants discharged. 125.67 Section 125.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION... discharge may result in any new or substantially increased discharges of the pollutant to which...

  19. CATALYTIC OXIDATION OF AIR POLLUTANTS FROM PULP AND PAPER INDUSTRY USING OZONE

    EPA Science Inventory

    Major pollutants from pulp and paper mills include volatile organic compounds (VOCs) such as methanol and total reduced sulfur compounds (TRS) such as dimethyl sulfide. The conventional treatment technologies including incineration or catalytic thermal oxidation are energy intens...

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

    EPA Science Inventory

    Ozone (O3) is a well-documented respiratory oxidant, but increasing epidemiologic evidence points to extra-pulmonary effects including positive associations between ambient O3 concentrations and cardiovascular morbidity/mortality. With preliminary reports linking O3 exposure wit...

  1. Foliar phenolics in sugar maple (Acer saccharum) as a potential indicator of tropospheric ozone pollution.

    PubMed

    Sager, E P S; Hutchinson, T C; Croley, T R

    2005-06-01

    Tropospheric O3 has been implicated in the declining health of forest ecosystems in Europe and North America and has been shown to have negative consequences on human health. We have measured tropospheric ozone (O3) in the lower canopy through the use of passive monitors located in five woodlots along a 150 km urban-rural transect, originating in the large urban complex of Toronto, Canada. We also sampled foliage from 10 mature sugar maple trees in each woodlot and measured the concentration of a number of phenolic compounds and macronutrients. O3 concentrations were highest in the two rural woodlots, located approximately 150 km downwind of Toronto, when compared to the woodlots found within the Greater Toronto Area. Foliar concentrations of three flavonoids, avicularin, isoquercitrin, and quercitrin, were significantly greater and nitrogen concentrations significantly lower at these same rural woodlots, suggesting some physiological disruption is occurring in those sites where exposure to tropospheric O3 is greater. We suggest that foliar phenolics of sugar maple may be a biochemical indicator of tropospheric ozone exposure.

  2. Ozone sensitivity to its precursor emissions in northeastern Mexico for a summer air pollution episode.

    PubMed

    Sierra, A; Vanoye, A Y; Mendoza, A

    2013-10-01

    A summer episode was modeled to address the expected response of ambient air O3 to hypothetical emission control scenarios in northeastern Mexico, and in particular in the Monterrey Metropolitan Area (MMA). This region is of interest because the MMA holds one of the worst air quality problems in the country and levels of air pollutants in the rest of northeastern Mexico are starting to be a concern. The MM5-SMOKE-CMAQ platform was used to conduct the numerical experiments. Twenty-four control scenarios were evaluated, combining the level of emission controls of O3 precursors (NO(x) and volatile organic compounds [VOCs]) from 0% to 50%. For the MMA, VOC-only controls result in the best option to reduce O3 concentrations, though the benefit is limited to the urban core. This same strategy results in negligible benefits for the rest of northeastern Mexico. NO(x) controls result in an increase in O3 concentration within the MMA of up to 20 ppbv and a decrease at downwind locations of up to 11 ppbv, with respect to the base-case scenario. Indicator ratios were also used to probe for NO(x)-sensitive and VOC-sensitive areas. Locations with an important influence of NO(x) point sources (i.e., Monclova and Nava/Acuña) are quite sensitive to changes in NO(x) emissions. Border cities in the Rio Bravo/Grande Valley tend to be marginally NO(x)-sensitive. Overall, the MMA seems to be dominated by a VOC-sensitive regime, while the rest of the region would tend to have a NO(x)-sensitive response. The results obtained serve to expand the current knowledge on the chemical regimes that dominate this region (VOC- or NO(x)-sensitive), and thus could help guide public policies related to emission regional control strategies. PMID:24282975

  3. Increasing spatiotemporal resolution of several major pollutant species in the Atlanta Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Brosius, A. L.; Luong, K. Y.

    2014-12-01

    The American Lung Association cited Atlanta, Georgia, as one of the top 20 most polluted U.S. cities in 2014. Heavy air and ground transportation traffic contribute to the production of carbon dioxide (CO2), particulate matter (PM), and tropospheric ozone (O3) for the Atlanta Metropolitan Area (AMA). Hartsfield-Jackson Atlanta International Airport contributes significantly to the emission of these pollutants and their precursors. This study focuses on enhancing spatiotemporal resolution of CO2, PM, and O3in near-surface (ground to 50m) air columns by using Arduino-based sensors. The city of Decatur, due to its proximity to the airport, is the study site for the investigation of target pollutant concentrations. The results of this study, combined with other metropolitan air quality data sets, can be used to verify projected trends and append seasonal data. An understanding of the pollutant concentration distributions throughout the near-surface air column is vital to providing insight into the fluctuation of urban area pollutants.

  4. Individuals with increased inflammatory response to ozone demonstrate muted signaling of immune cell trafficking pathways

    EPA Science Inventory

    Background Exposure to ozone activates innate immune function and causes neutrophilic (PMN) airway inflammation that in some individuals is robustly elevated. The interplay between immunoinflammatory function and genomic signaling in those with heightened inflammatory responsive...

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

    PubMed

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

    2000-06-01

    Ozone in ambient air may cause various effects on human health, including decreased lung function, asthma exacerbation, and even premature mortality. These effects have been evidenced using various clinical indicators that, although sensitive, do not specifically evaluate the O(3)-increased lung epithelium permeability. In the present study, we assessed the acute effects of ambient O(3) on the pulmonary epithelium by a new approach relying on the assay in serum of the lung-specific Clara cell protein (CC16 or CC10). We applied this test to cyclists who exercised for 2 hr during episodes of photochemical smog and found that O(3) induces an early leakage of lung Clara cell protein. The protein levels increased significantly into the serum from exposure levels as low as 0.060-0.084 ppm. Our findings, confirmed in mice exposed to the current U.S. National Ambient Air Quality Standards for O(3) (0.08 ppm for 8 hr) indicate that above the present natural background levels, there is almost no safety margin for the effects of ambient O(3) on airway permeability. The assay of CC16 in the serum represents a new sensitive noninvasive test allowing the detection of early effects of ambient O(3) on the lung epithelial barrier. PMID:10856027

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

    PubMed Central

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

    2000-01-01

    Ozone in ambient air may cause various effects on human health, including decreased lung function, asthma exacerbation, and even premature mortality. These effects have been evidenced using various clinical indicators that, although sensitive, do not specifically evaluate the O(3)-increased lung epithelium permeability. In the present study, we assessed the acute effects of ambient O(3) on the pulmonary epithelium by a new approach relying on the assay in serum of the lung-specific Clara cell protein (CC16 or CC10). We applied this test to cyclists who exercised for 2 hr during episodes of photochemical smog and found that O(3) induces an early leakage of lung Clara cell protein. The protein levels increased significantly into the serum from exposure levels as low as 0.060-0.084 ppm. Our findings, confirmed in mice exposed to the current U.S. National Ambient Air Quality Standards for O(3) (0.08 ppm for 8 hr) indicate that above the present natural background levels, there is almost no safety margin for the effects of ambient O(3) on airway permeability. The assay of CC16 in the serum represents a new sensitive noninvasive test allowing the detection of early effects of ambient O(3) on the lung epithelial barrier. Images Figure 1 Figure 2 Figure 3 PMID:10856027

  7. Individuals with increased inflammatory response to ozone demonstrate muted signaling of immune cell trafficking pathways

    PubMed Central

    2012-01-01

    Background Exposure to ozone activates innate immune function and causes neutrophilic (PMN) airway inflammation that in some individuals is robustly elevated. The interplay between immuno-inflammatory function and genomic signaling in those with heightened inflammatory responsiveness to ozone is not well understood. Objectives Determine baseline predictors and post exposure discriminators for the immuno-inflammatory response to ozone in inflammatory responsive adult volunteers. Methods Sputum induction was performed on 27 individuals before and after a two hour chamber exposure to 0.4 ppm ozone. Subjects were classified as inflammatory responders or non-responders to ozone based on their PMN response. Innate immune function, inflammatory cell and cytokine modulation and transcriptional signaling pathways were measured in sputum. Results Post exposure, responders showed activated innate immune function (CD16: 31,004 MFI vs 8988 MFI; CD11b: 44,986 MFI vs 24,770 MFI; CD80: 2236 MFI vs 1506 MFI; IL-8: 37,603 pg/ml vs 2828 pg/ml; and IL-1β: 1380 pg/ml vs 318 pg/ml) with muted signaling of immune cell trafficking pathways. In contrast, non-responders displayed decreased innate immune activity (CD16, CD80; phagocytosis: 2 particles/PMN vs 4 particles/PMN) post exposure that was accompanied by a heightened signaling of immune cell trafficking pathways. Conclusions Inflammatory responsive and non responsive individuals to ozone show an inverse relationship between immune cell trafficking and immuno-inflammatory functional responses to ozone. These distinct genomic signatures may further our understanding about ozone-induced morbidity in individuals with different levels of inflammatory responsiveness. PMID:23033980

  8. Air pollution and associated human mortality: The role of air pollutant emissions, climate change and methane concentration increases during the industrial period

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Naik, V.; Horowitz, L. W.; Mauzerall, D. L.

    2012-12-01

    Increases in surface ozone (O3) and fine particulate matter (≤ 2.5μm aerodynamic diameter, PM2.5) are associated with excess premature human mortalities. Here we estimate changes in surface O3 and PM2.5 since preindustrial (1860) times and the global present-day (2000) premature human mortalities associated with these changes. We go beyond previous work to analyze and differentiate the contribution of three factors: changes in emissions of short-lived air pollutants, climate change, and increased methane (CH4) concentrations, to air pollution levels and the associated premature mortalities. We use a coupled chemistry-climate model in conjunction with global population distributions in 2000 to estimate exposure attributable to concentration changes since 1860 from each factor. Attributable mortalities are estimated using health impact functions of long-term relative risk estimates for O3 and PM2.5 from the epidemiology literature. We find global mean surface PM2.5 and health-relevant O3 (defined as the maximum 6-month mean of 1-hour daily maximum O3 in a year) have increased by 8±0.16 μg/m3 and 30±0.16 ppbv, respectively, over this industrial period as a result of combined changes in emissions of air pollutants (EMIS), climate (CLIM) and CH4 concentrations (TCH4). EMIS, CLIM and TCH4 cause global average PM2.5 (O3) to change by +7.5±0.19 μg/m3 (+25±0.30 ppbv), +0.4±0.17 μg/m3 (+0.5±0.28 ppbv), and -0.02±0.01 μg/m3 (+4.3±0.33 ppbv), respectively. Total changes in PM2.5 are associated with 1.5 (95% confidence interval, CI, 1.0-2.5) million all-cause mortalities annually and in O3 are associated with 375 (95% CI, 129-592) thousand respiratory mortalities annually. Most air pollution mortality is driven by changes in emissions of short-lived air pollutants and their precursors (95% and 85% of mortalities from PM2.5 and O3 respectively). However, changing climate and increasing CH4 concentrations also increased premature mortality associated with air

  9. Air pollution and associated human mortality: the role of air pollutant emissions, climate change and methane concentration increases during the industrial period

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Naik, V.; Horowitz, L. W.; Mauzerall, D. L.

    2012-09-01

    Increases in surface ozone (O3) and fine particulate matter (≤2.5 μm} aerodynamic diameter, PM2.5) are associated with excess premature human mortalities. Here we estimate changes in surface O3 and PM2.5 since preindustrial (1860) times and the global present-day (2000) premature human mortalities associated with these changes. We go beyond previous work to analyze and differentiate the contribution of three factors: changes in emissions of short-lived air pollutants, climate change, and increased methane (CH4) concentrations, to air pollution levels and the associated premature mortalities. We use a coupled chemistry-climate model in conjunction with global population distributions in 2000 to estimate exposure attributable to concentration changes since 1860 from each factor. Attributable mortalities are estimated using health impact functions of long-term relative risk estimates for O3 and PM2.5 from the epidemiology literature. We find global mean surface PM2.5 and health-relevant O3 (defined as the maximum 6-month mean of 1-h daily maximum O3 in a year) have increased by 8 ± 0.16 μg m-3 and 30 ± 0.16 ppbv, respectively, over this industrial period as a result of combined changes in emissions of air pollutants (EMIS), climate (CLIM) and CH4 concentrations (TCH4). EMIS, CLIM and TCH4 cause global average PM2.5(O3) to change by +7.5 ± 0.19 μg m-3 (+25 ± 0.30 ppbv), +0.4 ± 0.17 μg m-3 (+0.5 ± 0.28 ppbv), and -0.02 ± 0.01 μg m-3 (+4.3 ± 0.33 ppbv), respectively. Total changes in PM2.5 are associated with 1.5 (95% confidence interval, CI, 1.0-2.5) million all-cause mortalities annually and in O3 are associated with 375 (95% CI, 129-592) thousand respiratory mortalities annually. Most air pollution mortality is driven by changes in emissions of short-lived air pollutants and their precursors (95% and 85% of mortalities from PM2.5 and O3, respectively). However, changing climate and increasing CH4 concentrations also increased premature mortality

  10. Projected carbon dioxide to increase grass pollen and allergen exposure despite higher ozone levels.

    PubMed

    Albertine, Jennifer M; Manning, William J; DaCosta, Michelle; Stinson, Kristina A; Muilenberg, Michael L; Rogers, Christine A

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10-30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change.

  11. Projected carbon dioxide to increase grass pollen and allergen exposure despite higher ozone levels.

    PubMed

    Albertine, Jennifer M; Manning, William J; DaCosta, Michelle; Stinson, Kristina A; Muilenberg, Michael L; Rogers, Christine A

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10-30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change. PMID:25372614

  12. Coarse Particulate Air Pollution Associated with Increased Risk of Hospital Admissions for Respiratory Diseases in a Tropical City, Kaohsiung, Taiwan

    PubMed Central

    Cheng, Meng-Hsuan; Chiu, Hui-Fen; Yang, Chun-Yuh

    2015-01-01

    This study was undertaken to determine whether there was an association between coarse particles (PM2.5–10) levels and frequency of hospital admissions for respiratory diseases (RD) in Kaohsiung, Taiwan. Hospital admissions for RD including chronic obstructive pulmonary disease (COPD), asthma, and pneumonia, and ambient air pollution data levels for Kaohsiung were obtained for the period from 2006 to 2010. The relative risk of hospital admissions for RD was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single pollutant model (without adjustment for other pollutants), increased rate of admissions for RD were significantly associated with higher coarse PM levels only on cool days (<25 °C), with a 10 µg/m3 elevation in PM2.5–10 concentrations associated with a 3% (95% CI = 1%–5%) rise in COPD admissions, 4% (95% CI = 1%–7%) increase in asthma admissions, and 3% (95% CI = 2%–4%) rise in pneumonia admissions. No significant associations were found between coarse particle levels and the number of hospital admissions for RD on warm days. In the two-pollutant models, PM2.5–10 levels remained significantly correlated with higher rate of RD admissions even controlling for sulfur dioxide, nitrogen dioxide, carbon monoxide, or ozone on cool days. This study provides evidence that higher levels of PM2.5–10 enhance the risk of hospital admissions for RD on cool days. PMID:26501308

  13. [Pollution characteristics and ozone formation potential of ambient VOCs in winter and spring in Xiamen].

    PubMed

    Xu, Hui; Zhang, Han; Xing, Zhen-yu; Deng, Jun-jun

    2015-01-01

    Air samples were collected at urban and rural sites in Xiamen from January to April 2014. The concentrations of 48 ambient volatile organic compounds (VOC) species were measured by the method of cryogenic pre-concentrator and gas chromatography-mass spectrometry (GC/MS). The ozone formation potential (OFP) of VOCs was also calculated with the method of maximum incremental reactivity (MIR). The results showed that the average mixing ratios of VOCs in winter were 11.13 x 10(-9) and 7.17 x 10(-9) at urban and rural sites, respectively, and those in spring were 24.88 x 10(-9) and 11.27 x 10(-9) at urban and rural sites, respectively. At both sites, alkanes contributed the most to VOCs, followed by aromatics and alkenes. The ratios of B/T showed that vehicle and solvent evaporation were the main sources of VOCs at urban site. While at rural site, transport of anthropogenic sources was another important source of VOCs besides local biomass emissions. Ten main components including propene, n-butane, i-butane, n-pentane, i-pentane, n-hexane, benzene, toluene, ethylbenzene and m/p-xylene accounted for 61.57% and 45.83% of total VOCs at urban and rural sites in winter, respectively, and 62.83% and 53.74% at urban and rural sites in spring, respectively. Aromatics contributed the most to total OFP, followed by alkenes. Alkanes contributed the least to OFP with the highest concentration. C3, C4 alkenes and aromatics were found to be the more reactive species with relatively high contributions to ozone formation in Xiamen. Comparing the average MIR of VOCs at the two sites, it was found that the reactivity of VOCs at rural site was higher than that at urban site. PMID:25898641

  14. Surface recombination of oxygen atoms in O2 plasma at increased pressure: II. Vibrational temperature and surface production of ozone

    NASA Astrophysics Data System (ADS)

    Lopaev, D. V.; Malykhin, E. M.; Zyryanov, S. M.

    2011-01-01

    Ozone production in an oxygen glow discharge in a quartz tube was studied in the pressure range of 10-50 Torr. The O3 density distribution along the tube diameter was measured by UV absorption spectroscopy, and ozone vibrational temperature TV was found comparing the calculated ab initio absorption spectra with the experimental ones. It has been shown that the O3 production mainly occurs on a tube surface whereas ozone is lost in the tube centre where in contrast the electron and oxygen atom densities are maximal. Two models were used to analyse the obtained results. The first one is a kinetic 1D model for the processes occurring near the tube walls with the participation of the main particles: O(3P), O2, O2(1Δg) and O3 molecules in different vibrational states. The agreement of O3 and O(3P) density profiles and TV calculated in the model with observed ones was reached by varying the single model parameter—ozone production probability (\\gamma_{O_{3}}) on the quartz tube surface on the assumption that O3 production occurs mainly in the surface recombination of physisorbed O(3P) and O2. The phenomenological model of the surface processes with the participation of oxygen atoms and molecules including singlet oxygen molecules was also considered to analyse \\gamma_{O_{3}} data obtained in the kinetic model. A good agreement between the experimental data and the data of both models—the kinetic 1D model and the phenomenological surface model—was obtained in the full range of the studied conditions that allowed consideration of the ozone surface production mechanism in more detail. The important role of singlet oxygen in ozone surface production was shown. The O3 surface production rate directly depends on the density of physisorbed oxygen atoms and molecules and can be high with increasing pressure and energy inputted into plasma while simultaneously keeping the surface temperature low enough. Using the special discharge cell design, such an approach opens up the

  15. Increased outdoor recreation, diminished ozone layer pose ultraviolet radiation threat to eye

    SciTech Connect

    Not Available

    1989-02-24

    The long-term effects of ultraviolet (UV) light on the eye are of increasing concern as many people live longer and spend more of that time in outdoor recreation and as the diminishing ozone layer filters less UV light. Ultraviolet radiation is strongest at high altitude, low latitude, and open for reflective environments (sand, snow, or water). For people who lack an eye lens (aphakics), UV light is transmitted directly onto the retina. Cumulative exposure to the 300- to 400-nm range of UV light is one factor causing cataracts. Ophthalmologists say cataracts cause visual deficits for more than 3.5 million people in the United States. Cumulative UV exposure may lead to age-related macular degeneration. At a Research to Prevent Blindness conference in Arlington, VA, John S. Werner, PhD, professor of psychology and neurosciences at the University of Colorado, Boulder, described how his group demonstrated the effects of UV light on retinal cones. Different types of intraocular lenses were placed in each eye of eight patients who had undergone bilateral cataract surgery. After five years, retinal cones chronically exposured to UV radiation had less sensitivity for short wavelengths (440 nm) by a factor of 1.7.

  16. Corticosteroid administration modifies ozone-induced increases in sheep airway blood flow

    SciTech Connect

    Gunther, R.A.; Yousef, M.A.; Schelegle, E.S.; Cross, C.E. )

    1992-09-01

    Recently, we have shown that exposure of intubated conscious sheep to 3 to 4 ppm ozone (O3) for 3 h increases bronchial blood flow (Qbr). The purpose of the present study was to assess the potential role of corticosteroids in modulating this increase. Six nasally intubated sheep were exposed to filtered room air, 3.5 ppm O3 on two separate occasions, and 3.5 ppm O3 plus methyl-prednisone, for 3 h. Qbr was measured using a chronically implanted 20 MHz pulsed Doppler flow probe. Qbr, mean aortic pressure, cardiac output, pulmonary artery pressure, arterial blood gases, and core temperature were monitored. After 3 h of 3.5 ppm O3, Qbr increased from 3.2 +/- 0.5 (mean +/- SEM) to 8.5 +/- 1.6 KHz, whereas bronchial vascular resistance (BVR) decreased from the baseline value of 43.6 +/- 8.0 to 15.0 +/- 3 mm Hg/KHz. With corticosteroids, baseline Qbr was 3.2 +/- 0.6 and BVR was 44.2 +/- 9.7; after 3 h of 3.5 ppm O3, Qbr was 3.3 +/- 0.5 KHz and BVR was 39.0 +/- 8.0 mm Hg/KHz. The two 3.5-ppm O3 exposures without corticosteroids were impressively reproducible. Except for Qbr and BVR, no other measured cardiovascular parameters were affected by O3. The results indicate that corticosteroids are capable of interfering with mediator, neurohumoral, or inflammatory cell mechanisms responsible for vasodilation of the airway microcirculation after O3 exposure, but do not specifically address the specific processes whereby this attenuation occurs.

  17. Potential of the multispectral synergism for observing ozone pollution combining measurements of IASI-NG and UVNS onboard EPS-SG

    NASA Astrophysics Data System (ADS)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2016-04-01

    Current and future satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors offer a limited capacity to probe surface concentrations of gaseous pollutants such as tropospheric ozone. Using single-band approaches based on IASI spaceborne thermal infrared measurements, only ozone down to the lower troposphere (3-4 km of altitude at lowest) may be observed (Eremenko et al., 2008). A recent multispectral method combining IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the IR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere, but with maximum sensitivity around 2 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years, such as EPS-SG, carrying new generation sensors like IASI-NG and UVNS that will enhance the capacity to observe ozone pollution, and particularly when combining them through a multispectral synergism. This work presents an analysis of the potential of the multispectral synergism of IASI-NG and UVNS future spaceborne measurements for observing ozone pollution, performed in the framework of SURVEYOZON project (funded by the French Space Agency, CNES). For this, we develop a simulator of synthetic multispectral retrievals or pseudo-observations (referred as OSSE, Observing System Simulation Experiment) derived from IASI-NG+UVNS that will be compared to those from IASI+GOME2. In the first step of the OSSE, we create a pseudo-reality with simulations from the chemical-transport model MOCAGE (provided by CERFACS laboratory), where real O3 data from IASI and surface network stations have been assimilated for a realistic representation of ozone variability at the surface and the free troposphere. We focus on the high pollution event occurred in Europe on 10 July 2010. We use the coupled algorithms KOPRA+VLIDORT to simulate the spectra emitted, scattered and

  18. Validation of the stomatal flux approach for the assessment of ozone visible injury in young forest trees. Results from the TOP (transboundary ozone pollution) experiment at Curno, Italy.

    PubMed

    Gerosa, G; Marzuoli, R; Desotgiu, R; Bussotti, F; Ballarin-Denti, A

    2009-05-01

    This paper summarises some of the main results of a two-year experiment carried out in an Open-Top Chambers facility in Northern Italy. Seedlings of Populus nigra, Fagus sylvatica, Quercus robur and Fraxinus excelsior have been subjected to different ozone treatments (charcoal-filtered and non-filtered air) and soil moisture regimes (irrigated and non-irrigated plots). Stomatal conductance models were applied and parameterised under South Alpine environmental conditions and stomatal ozone fluxes have been calculated. The flux-based approach provided a better performance than AOT40 in predicting the onset of foliar visible injuries. Critical flux levels, related to visible leaf injury, are proposed for P. nigra and F. sylvatica (ranging between 30 and 33 mmol O(3) m(-2)). Soil water stress delayed visible injury appearance and development by limiting ozone uptake. Data from charcoal-filtered treatments suggest the existence of an hourly flux threshold, below which may occur a complete ozone detoxification.

  19. 40 CFR 125.67 - Increase in effluent volume or amount of pollutants discharged.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Increase in effluent volume or amount... Water Act § 125.67 Increase in effluent volume or amount of pollutants discharged. (a) No modified... projections of effluent volume and mass loadings for any pollutants to which the modification applies in...

  20. Ambient ozone causes upper airways inflammation in children.

    PubMed

    Frischer, T M; Kuehr, J; Pullwitt, A; Meinert, R; Forster, J; Studnicka, M; Koren, H

    1993-10-01

    Ozone constitutes a major air pollutant in Western Europe. During the summer national air quality standards are frequently exceeded, which justifies concern about the health effects of ozone at ambient concentrations. We studied upper airways inflammation after ozone exposure in 44 children by repeated nasal lavages from May to October 1991. During this time period five to eight lavages were performed for each child. On 14 days following high ozone exposure (daily maximum > or = 180 micrograms/m3) 148 nasal lavages were performed, and on 10 days following low ozone exposure (daily maximum < or = 140 micrograms/m3) 106 nasal lavages were performed. A significant increase of intra-individual mean polymorphonuclear leukocytes (PMN) counts from low ozone days (median, 20.27 x 10(3)) to high ozone days (median, 27.38 x 10(3); p < 0.01) was observed. Concomitant with a decrease of ozone concentrations in the fall mean PMN counts showed a downward trend. Linear regression analysis of log-PMN counts yielded a significant effect for ozone (p = 0.017). In a subsample humoral markers of inflammation were measured for each child's highest and lowest exposure. A significant increase was observed for eosinophilic cationic protein (median, 77.39 micrograms/L on low ozone days versus 138.6 micrograms/L on high ozone days; p < 0.05). Thus we conclude that ozone at ambient concentrations initiates a reversible inflammatory response of the upper airways in normal children.

  1. Evaluation of the use of empirical ambient ozone pollutant modeling and subject activity logs as an indirect measurement of ozone exposure

    SciTech Connect

    Hopkins, L.P.; Fraser, M.P.; Ensor, K.B.; Rifai, H.S.

    1998-12-31

    The personal ozone exposure of women on the track team at Rice University was monitored using Harvard passive samplers over a period of six weeks during August and September of 1997. Each subject logged their location and activity in and around campus during the exposure period. A three-dimensional kriging model of ozone was developed to estimate the ozone exposure for each subject from ambient fixed site monitoring data. The ozone predictions from the model were combined with the activity and location information, adjusted for indoor environment when applicable, to estimate personal exposure concentrations for each subject. Using two independent approaches, the kriging model was proven to provide accurate spatial and temporal estimates of ozone at subject exposure points. The results from this work show that the method developed to estimate exposure through kriging over (x,y,t) to predict ozone concentrations at exposure points combined with subject activity/time logs produces exposure estimates within the error bounds of the analytical methods for personal monitoring.

  2. Increased site fertility and litter decomposition rate in high-pollution sites in the San Bernardino Mountains

    SciTech Connect

    Fenn, M. )

    1991-09-01

    Some possible factors causing enhanced litter decomposition in high-pollution sites in the San Bernardino Mountains of southern California were investigated. Nitrogen concentration of soil, as well as foliage and litter of ponderosa pine (Pinus ponderosa Laws.) and Jeffrey pine (Pinus jeffreyi Grev, and Balf.) were greater in high-pollution plots than in moderate- or low-pollution plots. Nitrogen concentration of soil, foliage, and litter of ponderosa pine (ozone-sensitive), and of the ozone-tolerant species, sugar pine (Pinus lambertiana Dougl.) and incense cedar (Calocedrus decurrens (Torr.) Florin.), were all higher at a higher pollution site than at a moderate-pollution site. The rate of litter decomposition for all three species was also greater at the high-pollution site. Results suggest than the primary factor causing enhanced decomposition of L-layer litter in high-pollution plots is greater site fertility, leading to the production of foliage and litter that is higher in N than litter from moderate- or low-pollution plots.

  3. The Relationship between the Western North Pacific Subtropical High and the East Asian Surface Ozone

    NASA Astrophysics Data System (ADS)

    Wie, Jieun; Kim, Ga-Young; Moon, Byung-Kwon

    2016-04-01

    The tropospheric ozone is known as one of the short-lived climate pollutants and the greenhouse gases, but little is known about it. The purpose of this study is to diagnose the relationship between the western North Pacific subtropical high and the East Asian surface ozone. For the study, we used the trajectory enhanced tropospheric ozone residual (TTOR) for 9 years (2005-2013) and GEOS-Chem model data for 41 years (1971-2011). Despite the short period, the observation well shows the ozone concentration changes according to the WNPSH strength and the model as well. WNPSH enhances the convection along the East Asian monsoon band and the surface ozone concentration decreases. The ozone concentration increases in the area around the rainband. Depending on the location of the rain band, the ozone concentration changes. This study indicates that the ozone concentration is affected by not only the emission of ozone precursors and but also the meteorological condition.

  4. Sensitivity analysis of ground level ozone in India using WRF-CMAQ models

    NASA Astrophysics Data System (ADS)

    Sharma, Sumit; Chatani, Satoru; Mahtta, Richa; Goel, Anju; Kumar, Atul

    2016-04-01

    Ground level ozone is emerging as a pollutant of concern in India. Limited surface monitoring data reveals that ozone concentrations are well above the prescribed national standards. This study aims to simulate the regional and urban scale ozone concentrations in India using WRF-CMAQ models. Sector-specific emission inventories are prepared for the ozone precursor species at a finer resolution (36 × 36 km2) than used in previous studies. Meteorological fields developed using the WRF model are fed into the CMAQ model along with the precursor emissions to simulate ozone concentrations at a regional scale. The model is validated using observed ozone dataset. Sensitivity analysis is carried out to understand the effect of different precursor species and sources on prevailing ozone concentrations in India. The results show that NOx sensitive conditions prevail in India and control of NOx will result in more reduction in ozone than VOCs. However, further growth in the transport and power sector and decreasing VOC emissions from the residential sector may increase the sensitivity of VOCs towards ozone in the future. At the urban scale, presence of high NOx emissions form VOC limited conditions and reduction of NOx results in increase in ozone concentrations. However, this will help in improving regional scale ozone pollution in the downwind regions. A non-linear response has been observed while assessing the sectoral sensitivities of ozone formation. Transport sector is found to have the maximum potential for reducing ozone concentrations in India.

  5. Air Quality Guide for Ozone

    MedlinePlus

    ... is one of our nation’s most common air pollutants. Use the chart below to help reduce your ... human health. Ozone forms when two types of pollutants (VOCs and NOx) react in sunlight. These pollutants ...

  6. Global Crop Yield Reductions due to Surface Ozone Exposure: Crop Production Losses and Economic Damage in 2000 and 2030 under Two Future Scenarios of O3 Pollution

    NASA Astrophysics Data System (ADS)

    Avnery, S.; Mauzerall, D. L.; Liu, J.; Horowitz, L. W.

    2011-12-01

    Field studies demonstrate that exposure to elevated concentrations of surface ozone (O3) may cause substantial reductions in the agricultural yields of many crops. As emissions of O3 precursors rise in many parts of the world over the next few decades, yield reductions from O3 exposure may increase the challenges of feeding a global population projected to grow from approximately 6 to 8 billion people between 2000 and 2030. This study estimates global yield reductions of three key staple crops (soybean, maize, and wheat) due to surface ozone exposure in 2000 and 2030 according to two trajectories of O3 pollution: the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A2 and B1 storylines, which represent upper- and lower-boundary projections, respectively, of most O3 precursor emissions in 2030. Our results indicate that year 2000 O3-induced global yield reductions ranged, depending on the O3 exposure metric used, from 3.9-15% for wheat, 8.5-14% for soybean, and 2.2-5.5% for maize. Global crop production losses totaled 79-121 million metric tons, worth 11-18 billion annually (USD2000). In the 2030-A2 scenario we find global O3-induced yield loss of wheat to be 5.4-26% (a further reduction in yield of +1.5-10% from year 2000 values), 15-19% for soybean (reduction of +0.9-11%), and 4.4-8.7% for maize (reduction of +2.1-3.2%) depending on the metric used, with total global agricultural losses worth 17-35 billion USD2000 annually (an increase of +6-17 billion in losses from 2000). Under the 2030-B1 scenario, we project less severe but still substantial reductions in yields: 4.0-17% for wheat (a further decrease in yield of +0.1-1.8% from 2000), 9.5-15% for soybean (decrease of +0.7-1.0%), and 2.5-6.0% for maize (decrease of+ 0.3-0.5%), with total losses worth 12-21 billion annually (an increase of +$1-3 billion in losses from 2000). Because our analysis uses crop data from the year 2000, which likely underestimates agricultural

  7. Potential sources of nitrous acid (HONO) and their impacts on ozone: A WRF-Chem study in a polluted subtropical region

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Wang, Tao; Zhang, Qiang; Zheng, Junyu; Xu, Zheng; Lv, Mengyao

    2016-04-01

    Current chemical transport models commonly undersimulate the atmospheric concentration of nitrous acid (HONO), which plays an important role in atmospheric chemistry, due to the lack or inappropriate representations of some sources in the models. In the present study, we parameterized up-to-date HONO sources into a state-of-the-art three-dimensional chemical transport model (Weather Research and Forecasting model coupled with Chemistry: WRF-Chem). These sources included (1) heterogeneous reactions on ground surfaces with the photoenhanced effect on HONO production, (2) photoenhanced reactions on aerosol surfaces, (3) direct vehicle and vessel emissions, (4) potential conversion of NO2 at the ocean surface, and (5) emissions from soil bacteria. The revised WRF-Chem was applied to explore the sources of the high HONO concentrations (0.45-2.71 ppb) observed at a suburban site located within complex land types (with artificial land covers, ocean, and forests) in Hong Kong. With the addition of these sources, the revised model substantially reproduced the observed HONO levels. The heterogeneous conversions of NO2 on ground surfaces dominated HONO sources contributing about 42% to the observed HONO mixing ratios, with emissions from soil bacterial contributing around 29%, followed by the oceanic source (~9%), photochemical formation via NO and OH (~6%), conversion on aerosol surfaces (~3%), and traffic emissions (~2%). The results suggest that HONO sources in suburban areas could be more complex and diverse than those in urban or rural areas and that the bacterial and/or ocean processes need to be considered in HONO production in forested and/or coastal areas. Sensitivity tests showed that the simulated HONO was sensitive to the uptake coefficient of NO2 on the surfaces. Incorporation of the aforementioned HONO sources significantly improved the simulations of ozone, resulting in increases of ground-level ozone concentrations by 6-12% over urban areas in Hong Kong and

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

    PubMed

    Cisneros, Ricardo; Bytnerowicz, Andrzej; Schweizer, Donald; Zhong, Sharon; Traina, Samuel; Bennett, Deborah H

    2010-10-01

    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 determined with seasonal means for individual sites ranging between 62 and 88 ppb for O3, 1.0-3.8 microg m(-3) for HNO3, and 2.6-5.2 microg m(-3) for NH3. Calculated O3 exposure indices were very high, reaching SUM00-191 ppm h, SUM60-151 ppm h, and W126-124 ppm h. Calculated nitrogen (N) dry deposition ranged from 1.4 to 15 kg N ha(-1) for maximum values, and 0.4-8 kg N ha(-1) for minimum values; potentially exceeding Critical Loads (CL) for nutritional N. The U.S., California, and European 8 h O3 human health standards were exceeded during 104, 108, and 114 days respectively, indicating high risk to humans from ambient O3. PMID:20708832

  9. High ozone increases soil perchlorate but does not affect foliar perchlorate content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ozone (O3) is implicated in the natural source inventory of perchlorate (ClO4-), a hydrophilic salt that migrates to ground water and interferes with uptake of iodide in mammals, including humans. Tropospheric O3 is elevated in many areas. We previously showed (Grantz et al., 2013; Environmental Pol...

  10. Duration of increased pulmonary function sensitivity to an initial ozone exposure

    SciTech Connect

    Bedi, J.F.; Drechsler-Parks, D.M.; Horvath, S.M.

    1985-12-01

    The metabolic and pulmonary function effects were investigated in six non-smoking young adults who were exposed for 2 hours (22 degrees C WBGT) to: filtered air (FA) 0.45 ppm ozone (DAY1); and two days later to a second exposure to 0.45 ppm ozone (DAY2). The subjects alternated 20-minute periods of rest and 20-minute periods of bicycle ergometer exercise at a workload predetermined to elicit a ventilatory minute volume (VE) of 27 L/min (BTPS). Functional residual capacity (FRC) was determined pre- and post-exposure. Forced vital capacity (FVC) was determined before and after exposure, as well as 5 minutes after each exercise period. Heart rate was monitored throughout the exposure, and VE, oxygen uptake (VO2), respiratory rate (fR), and tidal volume (VT) were measured during the last 2 minutes of each exercise period. There were no changes in any variable consequent to FA exposure. Both ozone exposures induced significant (P less than 0.05) decrements in FVC; FEV1.0 (forced expiratory volume in 1 second); FEV3.0 (forced expiratory volume in 3 seconds); FEF25-75% (average flow rate between 25% and 75% of FVC); and total lung capacity (TLC). The decrements following the DAY2 ozone exposure were significantly greater than following DAY1, and averaged 7.2 percentage points greater than those following the DAY1 exposure.

  11. Research Spotlight: Ozone hole shift exposed South America to increased ultraviolet light

    NASA Astrophysics Data System (ADS)

    Ofori, Leslie; Tretkoff, Ernie

    2010-12-01

    The ozone layer, which protects humans, plants, and animals from potentially damaging ultraviolet (UV) light from the Sun, develops a hole above Antarctica in September that typically lasts until early December. However, in November 2009, that hole shifted its position, leaving the southern tip of South America exposed to UV light at levels much greater than normal.

  12. Age, strain, and gender as factors for increased sensitivity of the mouse lung to inhaled ozone

    EPA Science Inventory

    Ozone (O(3)) is a respiratory irritant that leads to airway inflammation and pulmonary dysfunction. Animal studies show that neonates are more sensitive to O(3) inhalation than adults, and children represent a potentially susceptible population. This latter notion is not well est...

  13. IONS-06 Ozone Profiles in the Rural-Urban Transition at Mexico City in March 2006: Mixture of Pollution and UT/LS Waves

    NASA Astrophysics Data System (ADS)

    Thompson, A. M.; Long, R. B.; Miller, S. K.; Yorks, J. E.; Madigan, M. J.; Witte, J. C.; Kucsera, T. L.; Lefer, B.; Morris, G. A.

    2006-12-01

    We have used ozone profile data from soundings for better interpretation of atmospheric chemistry and dynamics at the urban-non-urban interface. Notably soundings have been taken during regional field campaigns like INTEX-NA (Intercontinental Transport Experiment - North America, 2004) and the 2006 Milagro/MIRAGE-Mex (Megacity Impacts of Regional and Global Environments)/ INTEX-B. IONS (INTEX Ozonesonde Network Study) is a network for studying the vertical structure and long-range transport of ozone and tropospheric water vapor during the INTEX experiments. In IONS-04, the urban-non-urban transition, was targeted at Beltsville, Maryland, a wooded suburban Washington DC site, and Narragansett, a coastal region downwind of New York City. From 5 to 20 March 2006, during IONS-06, ozone soundings were made over the Milagro T1 site (Tecamac, 19N, 99W), at the urban-rural interface, about 80 km NE of Mexico City. Simultaneous soundings were made over Houston, TX, 30N, 95W, approximately 1000 km to the northeast. Day-to-day variations in tropospheric ozone at T1 are explained by regional meteorology and emissions. Pollution accumulation at T1 was most noticeable during a stagnation period early in March, with winds from Mexico City. Downwind of T1, Houston was affected on 10 March 2006. In addition to pollution impacts, ozone variations throughout the troposphere and lower stratosphere over T1 were associated with equatorial Gravity waves. IONS-06 images for Mexico City/Tecamac, Houston, and those for other March 2006 data are viewable at: http://croc.gsfc.nasa.gov/intexb/ions06.

  14. Influence of high carbohydrate versus high fat diet in ozone induced pulmonary injury and systemic metabolic impairment in a Brown Norway (BN) rat model of healthy aging

    EPA Science Inventory

    Rationale: Air pollution has been recently linked to the increased prevalence of metabolic syndrome. It has been postulated that dietary risk factors might exacerbate air pollution-induced metabolic impairment. We have recently reported that ozone exposure induces acute systemic ...

  15. "OZONE SOURCE APPORTIONMENT IN CMAQ'

    EPA Science Inventory

    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 tran...

  16. 40 CFR 125.67 - Increase in effluent volume or amount of pollutants discharged.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 23 2013-07-01 2013-07-01 false Increase in effluent volume or amount of pollutants discharged. 125.67 Section 125.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM Criteria for Modifying the...

  17. Inquiry Based Projects Using Student Ozone Measurements and the Status of Using Plants as Bio-Indicators

    NASA Astrophysics Data System (ADS)

    Ladd, I. H.; Fishman, J.; Pippin, M.; Sachs, S.; Skelly, J.; Chappelka, A.; Neufeld, H.; Burkey, K.

    2006-05-01

    Students around the world work cooperatively with their teachers and the scientific research community measuring local surface ozone levels using a hand-held optical scanner and ozone sensitive chemical strips. Through the GLOBE (Global Learning and Observations to Benefit the Environment) Program, students measuring local ozone levels are connected with the chemistry of the air they breathe and how human activity impacts air quality. Educational tools have been developed and correlated with the National Science and Mathematics Standards to facilitate integrating the study of surface ozone with core curriculum. Ozone air pollution has been identified as the major pollutant causing foliar injury to plants when they are exposed to concentrations of surface ozone. The inclusion of native and agricultural plants with measuring surface ozone provides an Earth system approach to understanding surface ozone. An implementation guide for investigating ozone induced foliar injury has been developed and field tested. The guide, Using Sensitive Plants as Bio-Indicators of Ozone Pollution, provides: the background information and protocol for implementing an "Ozone Garden" with native and agricultural plants; and, a unique opportunity to involve students in a project that will develop and increase their awareness of surface ozone air pollution and its impact on plants.

  18. Coastal pollution due to increasing nutrient flux in aquaculture sites

    NASA Astrophysics Data System (ADS)

    David, C. P. C.; Sta. Maria, Y. Y.; Siringan, F. P.; Reotita, J. M.; Zamora, P. B.; Villanoy, C. L.; Sombrito, E. Z.; Azanza, R. V.

    2009-07-01

    The supply of nitrogen and phosphorus in coastal zones through time is reflected in the nutrients’ concentration in the sediment record. Five aquaculture sites in the Philippines were investigated in an effort to establish how long-term changes in land and coastal water use could have led to biogeochemical modifications affecting the coastal ecosystem. Samples from study sites show a narrow concentration range for nitrogen and did not reveal any significant trend through time. In contrast, phosphorus concentrations in most sites start at less than 20 ppm in sediments 30 years and older. The phosphorus value continuously increase in younger sediments, with each site having a different magnitude change as well as timing of when the major increase happened. The uppermost 10 cm, representing the last 15 years in sites with age control, typically show a 2- to 3-fold increase in P load values. Historical increase in nutrient load also coincides with harmful algal bloom events in each area; when effective P input exceeded 130 kg/km2 per year. Lastly, the observed increase may be attributed to several factors including physical attributes of the area, urbanization of coastal zones, but most importantly in the proliferation of aquaculture activities.

  19. Hydroponically cultivated radish fed L-galactono-1,4-lactone exhibit increased tolerance to ozone.

    PubMed

    Maddison, Joanna; Lyons, Tom; Plöchl, Matthias; Barnes, Jeremy

    2002-01-01

    Leaf L-ascorbate content of an ozone (O3)-sensitive radish genotype (Raphanus sativus L. cv. Cherry Belle) was increased 2-fold by feeding hydroponically cultivated plants L-galactono- 1,4-lactone (GalL). Plants were grown in controlled-environment chambers ventilated with charcoal/Purafil-filtered air, and administered one of two O3 fumigation regimes: chronic exposure (75 nmol O3 mol(-1) for 7 h day(-1) for 21 days) and acute exposure (180 nmol O3 mol(-1) for 9 h). Chronic O3 exposure decreased root growth by 11% in plants maintained in pure nutrient solution (-GalL), but resulted in no change in root growth in GalL-fed plants (+GalL). Similarly, GalL-feeding counteracted the negative effects of O3 on CO2 assimilation rate observed in control plants (-GalL). Under acute O3 exposure, GalL-fed plants showed none of the visible symptoms of injury, which were extensive in plants not fed GalL. Leaf CO2 assimilation rate was decreased by acute 03 exposure in both GalL treatments, but the extent of the decline was less marked in GalL-fed plants. No significant changes in stomatal conductance resulted from GalL treatment, so O3 Uptake into leaves was equivalent in + GalL and -GalL plants. Feeding GalL, on the other hand, enhanced the level of ascorbate, and resulted in the maintenance of the redox state of ascorbate under acute O3 fumigation, in both the leaf apoplast and symplast. The effect of GalL treatment on ascorbate pools was consistent with the reduction in O3 damage observed in GalL-fed plants. Attempts to model O3 interception by the ascorbate pool in the leaf apoplast suggested a greater capacity for O3 detoxification in GalL-fed plants, which corresponded with the increase in O3 tolerance observed. However, modelled data for GalL-fed plants suggested that additional constituents of the leaf apoplast may play an important role in the attenuation of environmentally-relevant O3 fluxes.

  20. Effects of ozone in normal human epidermal keratinocytes.

    PubMed

    McCarthy, James T; Pelle, Edward; Dong, Kelly; Brahmbhatt, Krupa; Yarosh, Dan; Pernodet, Nadine

    2013-05-01

    Ozone is a tropospheric pollutant that can form at ground level as a result of an interaction between sunlight and hydrocarbon engine emissions. As ozone is an extremely oxidative reaction product, epidermal cells are in the outer layer of defense against ozone. We exposed normal human epidermal keratinocytes (NHEK) to concentrations of ozone that have been measured in cities and assayed for its effects. Hydrogen peroxide and IL-1α levels both increased while ATP levels decreased. We found a decrease in the NAD-dependent histone deacetylase, sirtuin 3. Lastly, we found that ozone increased DNA damage as evaluated by Comet assay. Taken together, our results show increased damage to NHEK that will ultimately impair normal cellular function as a result of an environmentally relevant ozone exposure.

  1. Positive but variable sensitivity of August surface ozone to large-scale warming in the southeast United States

    NASA Astrophysics Data System (ADS)

    Fu, Tzung-May; Zheng, Yiqi; Paulot, Fabien; Mao, Jingqiu; Yantosca, Robert M.

    2015-05-01

    Surface ozone, a major air pollutant toxic to humans and damaging to ecosystems, is produced by the oxidation of volatile organic compounds in the presence of nitrogen oxides (NOx = NO + NO2) and sunlight. Climate warming may affect future surface ozone levels even in the absence of anthropogenic emission changes, but the direction of ozone change due to climate warming remains uncertain over the southeast US and other polluted forested areas. Here we use observations and simulations to diagnose the sensitivity of August surface ozone to large-scale temperature variations in the southeast US during 1988-2011. We show that the enhanced biogenic emissions and the accelerated photochemical reaction rates associated with warmer temperatures both act to increase surface ozone. However, the sensitivity of surface ozone to large-scale warming is highly variable on interannual and interdecadal timescales owing to variation in regional ozone advection. Our results have important implications for the prediction and management of future ozone air quality.

  2. Ozone reactivity and free radical scavenging behavior of phenolic secondary metabolites in lichens exposed to chronic oxidant air pollution from Mexico City.

    PubMed

    Valencia-Islas, N; Zambrano, A; Rojas, J L

    2007-08-01

    Lichen secondary metabolites putatively protect lichens from a variety of environmental stress factors, but it is unknown whether these substances respond to air pollution. To assess such a possibility, the three major phenolics of two epiphytic lichen species with contrasting tolerance to chronic air pollution from Mexico City were studied by combining experimental reactivity data and measured field contents. The antioxidant activity and antiradical power of boninic (BO), 2-O-methylsekikaic (MA), and usnic (US) acids, isolated from the tolerant Ramalina asahinae and salazinic acid (SA), atranorin (AT), and chloroatranorin (CA), from the sensitive Parmotrema stuppeum, were determined in vitro by kinetic experiments with ozone and the free radical diphenyl picryl hidrazyl (DPPH*), respectively. In addition, the field contents of these phenolics in the lichens, and the potential antioxidant capacity (PAC) they provide, were compared among three forested sites exposed to urban emissions and a similar, relatively clean site. The six phenolics had antioxidant activity and antiradical power according to these trends: CA > AT > US > SA > or = BO > or = MA for O(3); and CA > AT > US > MA > SA = BO for DPPH*. The three most reactive phenolics are cortical compounds, located in the lichen portion most exposed to the surrounding environment. In contrast, the less reactive SA, BO, and MA are medullary. Such reactivity patterns indicate that some phenolics may provide antioxidative protection at the air-lichen interface. The higher antioxidant power of CA and AT may be due to the reactive hydroxyl groups at positions 2 and 4 of ring A, instead of the less reactive methoxyl at the same positions in both BO and MA. In the field comparisons, total quantified phenolics were significantly higher near Mexico City for both lichens, except for the tolerant R. asahinae at one site. Nevertheless, only the latter species had significantly increased PAC values at all sites near the city

  3. Growth, physiological and biochemical response of ponderosa pine pinus ponderosa' to ozone. Final report

    SciTech Connect

    Temple, P.J.; Bytnerowicz, A.

    1993-11-01

    In 1989 and 1990, the effects of multi-year ozone exposures on growth, foliar injury and physiological responses in ponderosa pine were examined. Two-year old seedlings were exposed to four ozone treatments in open-top chambers: clean air (subambient levels of oxidants and particles); ambient ozone; twice-ambient ozone; or ambient air. The study was performed at Shirley Meadow in the southern Sierra Nevada. In both years, ambient ozone levels were representative of other forests in the region. While ozone is the most phytotoxic air pollutant, seedlings also experienced elevated concentrations of nitric acid and ammonia. In 1990, ambient ozone significantly increased injury to previous year needles. Premature senescence and alterations in physiological responses were also noted. Exposure to twice-ambient ozone reduced seedling biomass, increased injury and caused decreases in a variety of physiological responses.

  4. Energy efficiency for the removal of non-polar pollutants during ultraviolet irradiation, visible light photocatalysis and ozonation of a wastewater effluent.

    PubMed

    Santiago-Morales, Javier; Gómez, María José; Herrera-López, Sonia; Fernández-Alba, Amadeo R; García-Calvo, Eloy; Rosal, Roberto

    2013-10-01

    This study aims to assess the removal of a set of non-polar pollutants in biologically treated wastewater using ozonation, ultraviolet (UV 254 nm low pressure mercury lamp) and visible light (Xe-arc lamp) irradiation as well as visible light photocatalysis using Ce-doped TiO2. The compounds tracked include UV filters, synthetic musks, herbicides, insecticides, antiseptics and polyaromatic hydrocarbons. Raw wastewater and treated samples were analyzed using stir-bar sorptive extraction coupled with comprehensive two-dimensional gas chromatography (SBSE-CG × GC-TOF-MS). Ozone treatment could remove most pollutants with a global efficiency of over 95% for 209 μM ozone dosage. UV irradiation reduced the total concentration of the sixteen pollutants tested by an average of 63% with high removal of the sunscreen 2-ethylhexyl trans-4-methoxycinnamate (EHMC), the synthetic musk 7-acetyl-1,1,3,4,4,6-hexamethyltetrahydronaphthalene (tonalide, AHTN) and several herbicides. Visible light Ce-TiO2 photocatalysis reached ~70% overall removal with particularly high efficiency for synthetic musks. In terms of power usage efficiency expressed as nmol kJ(-1), the results showed that ozonation was by far the most efficient process, ten-fold over Xe/Ce-TiO2 visible light photocatalysis, the latter being in turn considerably more efficient than UV irradiation. In all cases the efficiency decreased along the treatments due to the lower reaction rate at lower pollutant concentration. The use of photocatalysis greatly improved the efficiency of visible light irradiation. The collector area per order decreased from 9.14 ± 5.11 m(2) m(-3) order(-1) for visible light irradiation to 0.16 ± 0.03 m(2) m(-3) order(-1) for Ce-TiO2 photocatalysis. The toxicity of treated wastewater was assessed using the green alga Pseudokirchneriella subcapitata. Ozonation reduced the toxicity of treated wastewater, while UV irradiation and visible light photocatalysis limited by 20-25% the algal growth due to

  5. Wind increase over cooling Southern Ocean driven by tropical warming and polar ozone hole

    NASA Astrophysics Data System (ADS)

    Schneider, D. P.; Fan, T.; Deser, C.

    2014-12-01

    Changing winds over the Southern Ocean have had dramatic impacts on Antarctic sea ice extent, anthropogenic heat and carbon uptake by the ocean, and the contribution of the Antarctic ice sheet to global sea level rise. An overall intensification of the surface westerly winds has been attributed to several different forcings, including stratospheric ozone depletion, greenhouse gasses, and tropical sea surface temperatures (SSTs). However, the relative roles of these drivers have not been well quantified. Reconciling previous explanations, here we show that a combination of tropical SSTs and stratospheric ozone loss largely explains the magnitude, regional patterns, and seasonality of observed lower tropospheric zonal wind trends over the Southern Ocean. We evaluate multiple ensembles of atmospheric model simulations, with each ensemble forced by one or a combination of drivers. Considering all months of the year, tropical SSTs are the largest contributor to observed zonal wind trends over 40°S-80°S. In austral summer, tropical SSTs and stratospheric ozone loss have contributed approximately equally to near-surface wind trends. The tropical contribution in austral summer is associated with tropics-wide warming, which has been moderated in recent decades by a prevalence of La-Niña events. The relative phasing of natural variability with anthropogenic forcing is therefore essential for understanding and predicting Southern Ocean climate change.

  6. Regional transport of pollutants over the Bay of Biscay: analysis of an ozone episode under a blocking anticyclone in west-central Europe

    NASA Astrophysics Data System (ADS)

    Gangoiti, Gotzon; Alonso, Lucio; Navazo, Marino; Albizuri, Amaia; Perez-Landa, Gorka; Matabuena, Monica; Valdenebro, Veronica; Maruri, Mercedes; Antonio García, José; Millán, Millán M.

    This paper analyses an ozone episode recorded at the regional monitoring network of the Basque Country, located in northern Iberia. The synoptic weather pattern was characterized by the presence of a blocking anticyclone over the British Isles and its subsequent evolution eastwards. The blocking situation lasted for 4 days, and ozone concentrations throughout the whole network rose up to 100-160 μg m -3. The main objective is to investigate the origin of the polluted air masses in the area and search for the transport/dispersion mechanisms that gave rise to such a severe O 3 episode. A mesoscale model, operating with three nested grids down to a resolution of 3 km×3 km, was used to simulate the mesoscale processes. The model results were validated against the output of a wind profiler radar and the meteorological data recorded at the surface meteorological stations operated by the local and regional authorities. Both the single-particle Lagrangian back-trajectories and the results of a multiple-particle dispersion model suggest that during the peak pollution episode there were contributions from local sources as well as regional and long-range transport from foreign sources. The transport mechanisms depend on the position-evolution of the high-pressure system over Europe: during the last phase of the episode (15-16 June 1996), concurrent with the highest concentrations, we detected both a contribution of pollutants from southern France, which arrived at the Bay of Biscay with the north-easterly winds forced by the European anticyclone, as well as a contribution from night-time discharges of aged pollutants located in the residual layer over the Ebro valley. This layer accumulates pollutants from local sources located inside the Ebro valley (daytime convection and mixing during the previous day) and can also be a reservoir of pollutants transported from the western Mediterranean following the sea breeze regime.

  7. An ozone episode over the Pearl River Delta in October 2008

    NASA Astrophysics Data System (ADS)

    Shen, Jin; Zhang, Yuanhang; Wang, Xuesong; Li, Jinfeng; Chen, Hao; Liu, Run; Zhong, Liuju; Jiang, Ming; Yue, Dingli; Chen, Duohong; Lv, Wei

    2015-12-01

    The north and east Pearl River Delta (PRD) is usually a clean, upwind area in autumn. Serious ozone pollution there in mid-late October 2008 was first discovered and then analyzed. Trajectory analysis, process analysis, ozone source apportionment technology, and sensitivity analysis were used to study this episode. Under the influence of a weak south wind, the precursors emitted in Guangzhou and Foshan were transported to the north and northeast PRD and formed ozone there, which resulted in high ozone concentration (>100 ppb). As the wind direction later transited to northerly, the precursors in the northeast PRD that originated from the central and west PRD were transported to the south, and caused severe ozone pollution in the southeast PRD. The ozone contributed by chemical processes reached >20 ppb/h in Jinguowan. More than 40 ppb ozone was contributed by the precursor emission in the central and west PRD during the episode. The ozone concentration was highly sensitive to the precursor emission in the PRD region in the high-ozone situations. This episode showed the complexity of regional pollution in the PRD. When the PRD is controlled by a low air pressure system and then cold air moves from northern China to the south, the risk of ozone pollution in the north and southeast PRD increases.

  8. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases.

    PubMed

    D'Amato, Gennaro; Baena-Cagnani, Carlos E; Cecchi, Lorenzo; Annesi-Maesano, Isabella; Nunes, Carlos; Ansotegui, Ignacio; D'Amato, Maria; Liccardi, Gennaro; Sofia, Matteo; Canonica, Walter G

    2013-01-01

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase.Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world.Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health.The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world.Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions.The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases.Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual's response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend

  9. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases

    PubMed Central

    2013-01-01

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase. Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world. Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health. The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world. Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions. The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases. Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual’s response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not

  10. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases.

    PubMed

    D'Amato, Gennaro; Baena-Cagnani, Carlos E; Cecchi, Lorenzo; Annesi-Maesano, Isabella; Nunes, Carlos; Ansotegui, Ignacio; D'Amato, Maria; Liccardi, Gennaro; Sofia, Matteo; Canonica, Walter G

    2013-02-11

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase.Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world.Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health.The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world.Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions.The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases.Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual's response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend

  11. Three-D Simulation of the Origin of the Pollutant Ozone Maxima in the Great African Plume: New Meteorology, New Chemistry for TRACE-A

    NASA Technical Reports Server (NTRS)

    Chatfeild, Robert; Vastano, John; Singh, Hanwant; Chan, K. Roland (Technical Monitor)

    1996-01-01

    Burning in South Central Africa is primarily responsible for the vast buildup of ozone in the mid-Atlantic noticeable in the Belem, Brazil, ozonesondes, and also visible in analyses using the Total Ozone Mapping Spectrometer (TOMS). We report on full-scale chemistry simulations for the SAFARI/TRACE-A field period of September-October, 1992. These observational programs provided a wealth of comparison data, including spectacular depictions of the vertical structure of ozone and particulate pollution over Africa, South America, and the Equatorial Atlantic [Browell JGR, 1996, submitted] above and below the NASA DC-8 airplane path. These depictions provide strict tests on the ability of a 3-d simulation and its controlling input parameters, most notably the biomass burning emissions strength. We use meteorology from MM5 used as a synoptic assimilation model and our own GRACES Global Regional Air Chemistry Event Simulator. This report will focus on the unique meteorology of the Equatorial Atmosphere around the Gulf of Guinea during the TRACE-A period, which we describe as "the opening of the gate," "the Great African Plume," and the "African Recirculatory System." We expect to assess whether the ozone observed is primarily "transported African smog," the standard view, or whether "re-$NO_[x)$-ification" of the Central Atlantic troposphere (reduction of nitric acid to active nitrogen oxides in clouds or aerosol) may be required for "extended intercontinental ozone production." A status report on a second nitrogen problem, "lower-tropospheric missing NO(y)," in which we find a serious imbalance in the $NO_ {x }$ and $NO_{y}$ budgets when compared with similar atmospheric tracers, will be given. An elaboration of the concepts set off by quotation marks in this abstract will be given in the talk.

  12. Simultaneous ozonation kinetics of phenolic acids present in wastewaters

    SciTech Connect

    Benitez, F.J.; Beltran-Heredia, J.; Acero, J.L.; Pinilla, M.L.

    1996-12-31

    Among the several chemical processes conducted for the removal of organic matter present in wastewaters coming from some agro-industrial plants (wine distilleries, olive oil mills, etc), the oxidation by ozone has shown a great effectiveness in the destruction of specially refractory pollutants: it is demonstrated that the biodegradability of those wastewaters increases aflcer an ozonation pretreatment. Their great pollutant character is imputed to the presence of some organic compounds, like phenols and polyphenols, which are toxic and inhibit the latter biological treatments. In this research, a competitive kinetic procedure reported by Clurol and Nekouinaini is applied to determine the degradation rate constants by ozone of several phenolic acids which are present in the wastewaters from the olive oil obtaining process. The resulting kinetic expressions for the ozonation reactions are useful for the successful design and operation of ozone reactors in water and wastewaters treatment plants.

  13. Observed Increase of TTL Temperature and Water Vapor in Polluted Couds over Asia

    SciTech Connect

    Su, Hui; Jiang, Jonathan; Liu, Xiaohong; Penner, J.; Read, William G.; Massie, Steven T.; Schoeberl, Mark R.; Colarco, Peter; Livesey, Nathaniel J.; Santee, Michelle L.

    2011-06-01

    Aerosols can affect cloud particle size and lifetime, which impacts precipitation, radiation and climate. Previous studies1-4 suggested that reduced ice cloud particle size and fall speed due to the influence of aerosols may increase evaporation of ice crystals and/or cloud radiative heating in the tropical tropopause layer (TTL), leading to higher water vapor abundance in air entering the stratosphere. Observational substantiation of such processes is still lacking. Here, we analyze new observations from multiple NASA satellites to show the imprint of pollution influence on stratospheric water vapor. We focus our analysis on the highly-polluted South and East Asia region during boreal summer. We find that "polluted" ice clouds have smaller ice effective radius than "clean" clouds. In the TTL, the polluted clouds are associated with warmer temperature and higher specific humidity than the clean clouds. The water vapor difference between the polluted and clean clouds cannot be explained by other meteorological factors, such as updraft and detrainment strength. Therefore, the observed higher water vapor entry value into the stratosphere in the polluted clouds than in the clean clouds is likely a manifestation of aerosol pollution influence on stratospheric water vapor. Given the radiative and chemical importance of stratospheric water vapor, the increasing emission of aerosols over Asia may have profound impacts on stratospheric chemistry and global energy balance and water cycle.

  14. Study of air pollution: Effects of ozone on neuropeptide-mediated responses in human subjects. Final report

    SciTech Connect

    Boushey, H.A.

    1991-11-01

    The study examined the hypothesis that ozone inactivates the enzyme, neutral endopeptidase, responsible for limiting the effects of neuropeptides released from afferent nerve endings. Cough response of capsaicin solution delivered from a nebulizer at 2 min. intervals until two or more coughs were produced. Other endpoints measured included irritative symptoms as rated by the subjects on a nonparametric scale, spirometry, of each concentration of ozone were compared to those of filtered air in a single-blind randomized sequence. The results indicate that a 2 h. exposure to 0.4 ppm of ozone with intermittent light exercise alters the sensitivity of airway nerves that mediate the cough response to inhaled materials. This dose of ozone also caused a change in FEV1. A lower level of ozone, 0.02 ppm, caused a change in neither cough threshold nor FEV1, even when the duration of exposure was extended to three hours. The findings are consistent with the author's hypothesis that ozone may sensitize nerve endings in the airways by inactivating neutral endopeptidase, an enzyme that regulates their activity, but they do not demonstrate that directly examining an effect directly mediated by airway nerves allows detection of effects of ozone at doses below those causing effects detected by standard tests of pulmonary function.

  15. The effects of increasing atmospheric ozone on biogenic monoterpene profiles and the formation of secondary aerosols

    NASA Astrophysics Data System (ADS)

    Pinto, Delia M.; Tiiva, Päivi; Miettinen, Pasi; Joutsensaari, Jorma; Kokkola, Harri; Nerg, Anne-Marja; Laaksonen, Ari; Holopainen, Jarmo K.

    Monoterpenes are biogenic volatile organic compounds (BVOCs) which play an important role in plant adaptation to stresses, atmospheric chemistry, plant-plant and plant-insect interactions. In this study, we determined whether ozonolysis can influence the monoterpenes in the headspace of cabbage. The monoterpenes were mixed with an air-flow enriched with 100, 200 or 400 ppbv of ozone (O 3) in a Teflon chamber. The changes in the monoterpene and O 3 concentrations, and the formation of secondary organic aerosols (SOA) were determined during ozonolysis. Furthermore, the monoterpene reactions with O 3 and OH were modelled using reaction kinetics equations. The results showed that all of the monoterpenes were unequally affected: α-thujene, sabinene and D-limonene were affected to the greatest extend, whereas the 1,8-cineole concentration did not change. In addition, plant monoterpene emissions reduced the O 3 concentration by 12-24%. The SOA formation was dependent on O 3 concentration. At 100 ppbv of O 3, virtually no new particles were formed but clear SOA formation was observed at the higher ozone concentrations. The modelled results showed rather good agreements for α-pinene and 1,8-cineole, whereas the measured concentrations were clearly lower compared to modelled values for sabinene and limonene. In summary, O 3-quenching by monoterpenes occurs beyond the boundary layer of leaves and results in a decreased O 3 concentration, altered monoterpene profiles and SOA formation.

  16. Assessment of the economic effects of ozone on US agriculture

    SciTech Connect

    Adams, R.M.; Hamilton, S.A.; McCarl, B.A.

    1985-01-01

    Past attempts to measure the economic consequences of ozone on agriculture have been based on limited plant science information. This paper reports on an economic assessment of ozone on US agriculture using recent crop response data from the National Crop Loss Assessment Network (NCLAN). The results are derived from a US agricultural sector model that includes major crop and livestock production as well as domestic consumption, livestock feeding and export uses. The economic effects of four hypothetical ambient ozone levels are investigated. The analysis indicates that the benefits to society of moderate (25%) ozone reductions are approximately $1.7 billion. A 25% increase in ozone pollution results in cost (negative benefits) of $2.1 billion. These estimates do not reflect compliance costs of achieving the ozone changes and hence are not net benefits.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26899381

  18. Ozone-Induced Metabolic Impairment is Attenuated in Adrenalectomized Wistar Kyoto Rats

    EPA Science Inventory

    Rationale: Air pollutants have been linked to increased incidence of metabolic syndrome however the mechanisms are poorly understood. We have recently shown that ozone exposure induces significant hyperglycemia together with elevated serum leptin and epinephrine in the Wistar Ky...

  19. Impact of increasing heat waves on U.S. ozone episodes in the 2050s: Results from a multimodel analysis using extreme value theory

    NASA Astrophysics Data System (ADS)

    Shen, L.; Mickley, L. J.; Gilleland, E.

    2016-04-01

    We develop a statistical model using extreme value theory to estimate the 2000-2050 changes in ozone episodes across the United States. We model the relationships between daily maximum temperature (Tmax) and maximum daily 8 h average (MDA8) ozone in May-September over 2003-2012 using a Point Process (PP) model. At ~20% of the sites, a marked decrease in the ozone-temperature slope occurs at high temperatures, defined as ozone suppression. The PP model sometimes fails to capture ozone-Tmax relationships, so we refit the ozone-Tmax slope using logistic regression and a generalized Pareto distribution model. We then apply the resulting hybrid-extreme value theory model to projections of Tmax from an ensemble of downscaled climate models. Assuming constant anthropogenic emissions at the present level, we find an average increase of 2.3 d a-1 in ozone episodes (>75 ppbv) across the United States by the 2050s, with a change of +3-9 d a-1 at many sites.

  20. Pharmaceuticals and organic pollution mitigation in reclamation osmosis brines by UV/H2O2 and ozone.

    PubMed

    Justo, A; González, O; Aceña, J; Pérez, S; Barceló, D; Sans, C; Esplugas, S

    2013-12-15

    One significant disadvantage of using reverse osmosis (RO) for reclamation purposes is the need to dispose of the RO retentates. These retentates contain a high concentration of micropollutants, effluent organic matter (EfOM) and other inorganic constituents, which are recalcitrant to biological treatment and may impact the environment. The occurrence of 11 pharmaceuticals (concentrations ranging from 0.2 to 1.6 μg L(-1)) and their mitigation in RO retentates by a UV/H2O2 process and ozonation was studied using a wide range of oxidant dosages. Eleven pharmaceuticals were identified at. Initial observed kinetic constants (kobs) were calculated for the different pharmaceuticals. Other typical wastewater parameters were also monitored during the UV/H2O2 and ozonation reactions. The range for kobs was found to be 0.8-12.8L mmol O3(-1) and 9.7-29.9 L mmol H2O2(-1) for the ozonation and UV/H2O2 process, respectively. For ozonation, Atenolol, Carbamazepine, Codeine, Trimethoprim and Diclofenac showed the lowest initial kobs (in the order mentioned). Atenolol and Carbamazepine appeared as the most ozone resistant pharmaceuticals, exhibiting the lowest percentage of elimination at low ozone doses. On the other hand, despite the non-selectivity of HO, differences in the initial kobs were also observed during the UV/H2O2 process. Trimethoprim, Paroxetine and Sulfamethoxazole exhibited the lowest initial kobs values (in the order mentioned). Trimethoprim and Paroxetine also exhibited the lowest percentage removal when low H2O2 doses were assayed. The compounds that were identified as problematic during ozonation were more efficiently removed by the UV/H2O2 process. UV/H2O2 generally appeared to be a more efficient technology for removing pharmaceuticals from RO brines compared to ozonation. PMID:23768786

  1. Pharmaceuticals and organic pollution mitigation in reclamation osmosis brines by UV/H2O2 and ozone.

    PubMed

    Justo, A; González, O; Aceña, J; Pérez, S; Barceló, D; Sans, C; Esplugas, S

    2013-12-15

    One significant disadvantage of using reverse osmosis (RO) for reclamation purposes is the need to dispose of the RO retentates. These retentates contain a high concentration of micropollutants, effluent organic matter (EfOM) and other inorganic constituents, which are recalcitrant to biological treatment and may impact the environment. The occurrence of 11 pharmaceuticals (concentrations ranging from 0.2 to 1.6 μg L(-1)) and their mitigation in RO retentates by a UV/H2O2 process and ozonation was studied using a wide range of oxidant dosages. Eleven pharmaceuticals were identified at. Initial observed kinetic constants (kobs) were calculated for the different pharmaceuticals. Other typical wastewater parameters were also monitored during the UV/H2O2 and ozonation reactions. The range for kobs was found to be 0.8-12.8L mmol O3(-1) and 9.7-29.9 L mmol H2O2(-1) for the ozonation and UV/H2O2 process, respectively. For ozonation, Atenolol, Carbamazepine, Codeine, Trimethoprim and Diclofenac showed the lowest initial kobs (in the order mentioned). Atenolol and Carbamazepine appeared as the most ozone resistant pharmaceuticals, exhibiting the lowest percentage of elimination at low ozone doses. On the other hand, despite the non-selectivity of HO, differences in the initial kobs were also observed during the UV/H2O2 process. Trimethoprim, Paroxetine and Sulfamethoxazole exhibited the lowest initial kobs values (in the order mentioned). Trimethoprim and Paroxetine also exhibited the lowest percentage removal when low H2O2 doses were assayed. The compounds that were identified as problematic during ozonation were more efficiently removed by the UV/H2O2 process. UV/H2O2 generally appeared to be a more efficient technology for removing pharmaceuticals from RO brines compared to ozonation.

  2. Spatial distribution of tropospheric ozone in western Washington, USA

    USGS Publications Warehouse

    Cooper, S.M.; Peterson, D.L.

    2000-01-01

    We quantified the distribution of tropospheric ozone in topographically complex western Washington state, USA (total area a??6000 km2), using passive ozone samplers along nine river drainages to measure ozone exposure from near sea level to high-elevation mountain sites. Weekly average ozone concentrations were higher with increasing distance from the urban core and at higher elevations, increasing a mean of 1.3 ppbv per 100 m elevation gain for all mountain transects. Weekly average ozone concentrations were generally highest in Cascade Mountains drainages east and southeast of Seattle (maximum=55a??67 pbv) and in the Columbia River Gorge east of Portland (maximum=59 ppbv), and lowest in the western Olympic Peninsula (maximum=34 ppbv). Higher ozone concentrations in the Cascade Mountains and Columbia River locations downwind of large cities indicate that significant quantities of ozone and ozone precursors are being transported eastward toward rural wildland areas by prevailing westerly winds. In addition, temporal (week to week) variation in ozone distribution is synchronous within and between all drainages sampled, which indicates that there is regional coherence in air pollution detectable with weekly averages. These data provide insight on large-scale spatial variation of ozone distribution in western Washington, and will help regulatory agencies optimize future monitoring networks and identify locations where human health and natural resources could be at risk.

  3. Spatial distribution of tropospheric ozone in western Washington, USA.

    PubMed

    Cooper, S M; Peterson, D L

    2000-03-01

    We quantified the distribution of tropospheric ozone in topographically complex western Washington state, USA (total area approximately 6000 km(2)), using passive ozone samplers along nine river drainages to measure ozone exposure from near sea level to high-elevation mountain sites. Weekly average ozone concentrations were higher with increasing distance from the urban core and at higher elevations, increasing a mean of 1.3 ppbv per 100 m elevation gain for all mountain transects. Weekly average ozone concentrations were generally highest in Cascade Mountains drainages east and southeast of Seattle (maximum=55-67 pbv) and in the Columbia River Gorge east of Portland (maximum=59 ppbv), and lowest in the western Olympic Peninsula (maximum=34 ppbv). Higher ozone concentrations in the Cascade Mountains and Columbia River locations downwind of large cities indicate that significant quantities of ozone and ozone precursors are being transported eastward toward rural wildland areas by prevailing westerly winds. In addition, temporal (week to week) variation in ozone distribution is synchronous within and between all drainages sampled, which indicates that there is regional coherence in air pollution detectable with weekly averages. These data provide insight on large-scale spatial variation of ozone distribution in western Washington, and will help regulatory agencies optimize future monitoring networks and identify locations where human health and natural resources could be at risk. PMID:15092980

  4. Isoprene chemistry in pristine and polluted Amazon environments: Eulerian and Lagrangian model frameworks and the strong bearing they have on our understanding of surface ozone and predictions of rainforest exposure to this priority pollutant

    NASA Astrophysics Data System (ADS)

    Levine, J. G.; MacKenzie, A. R.; Squire, O. J.; Archibald, A. T.; Griffiths, P. T.; Abraham, N. L.; Pyle, J. A.; Oram, D. E.; Forster, G.; Brito, J. F.; Lee, J. D.; Hopkins, J. R.; Lewis, A. C.; Bauguitte, S. J. B.; Demarco, C. F.; Artaxo, P.; Messina, P.; Lathière, J.; Hauglustaine, D. A.; House, E.; Hewitt, C. N.; Nemitz, E.

    2015-09-01

    This study explores our ability to simulate the atmospheric chemistry stemming from isoprene emissions in pristine and polluted regions of the Amazon basin. We confront two atmospheric chemistry models - a global, Eulerian chemistry-climate model (UM-UKCA) and a trajectory-based Lagrangian model (CiTTyCAT) - with recent airborne measurements of atmospheric composition above the Amazon made during the SAMBBA campaign of 2012. The simulations with the two models prove relatively insensitive to the chemical mechanism employed; we explore one based on the Mainz Isoprene Mechanism, and an updated one that includes changes to the chemistry of first generation isoprene nitrates (ISON) and the regeneration of hydroxyl radicals via the formation of hydroperoxy-aldehydes (HPALDS) from hydroperoxy radicals (ISO2). In the Lagrangian model, the impact of increasing the spatial resolution of trace gas emissions employed from 3.75° × 2.5° to 0.1° × 0.1° varies from one flight to another, and from one chemical species to another. What consistently proves highly influential on our simulations, however, is the model framework itself - how the treatment of transport, and consequently mixing, differs between the two models. The lack of explicit mixing in the Lagrangian model yields variability in atmospheric composition more reminiscent of that exhibited by the measurements. In contrast, the combination of explicit (and implicit) mixing in the Eulerian model removes much of this variability but yields better agreement with the measurements overall. We therefore explore a simple treatment of mixing in the Lagrangian model that, drawing on output from the Eulerian model, offers a compromise between the two models. We use this Lagrangian/Eulerian combination, in addition to the separate Eulerian and Lagrangian models, to simulate ozone at a site in the boundary layer downwind of Manaus, Brazil. The Lagrangian/Eulerian combination predicts a value for an AOT40-like accumulated

  5. Copper Pollution Increases the Relative Importance of Predation Risk in an Aquatic Food Web.

    PubMed

    Kwan, Christopher Kent; Sanford, Eric; Long, Jeremy

    2015-01-01

    Although the cascading impact of predators depends critically on the relative role of lethal predation and predation risk, we lack an understanding of how human-caused stressors may shift this balance. Emergent evidence suggests that pollution may increase the importance of predator consumptive effects by weakening the effects of fear perceived by prey. However, this oversimplification ignores the possibility that pollution may also alter predator consumptive effects. In particular, contaminants may impair the consumptive effects of predators by altering density-dependent interactions among prey conspecifics. No study has directly compared predator consumptive and non-consumptive effects in polluted versus non-polluted settings. We addressed this issue by using laboratory mesocosms to examine the impact of sublethal doses of copper on tri-trophic interactions among estuarine predator crabs Cancer productus, carnivorous whelk prey Urosalpinx cinerea, and the basal resource barnacles Balanus glandula. We investigated crab consumptive effects (whelks culled without crab chemical cues), non-consumptive effects (whelks not culled with crab chemical cues), and total effects (whelks culled with crab chemical cues) on whelks in copper polluted and non-polluted waters. Realistic copper concentrations suppressed the effects of simulated crab lethal predation (whelk culling) by removing density-dependent feeding by whelks. Specifically, reductions in conspecific density occurring in elevated copper levels did not trigger the normal increase in whelk consumption rates of barnacles. Weakened effects of fear were only observed at extremely high copper levels, suggesting consumptive effects were more sensitive to pollution. Thus, pollution may shape communities by altering the roles of predators and interactions among prey.

  6. Copper Pollution Increases the Relative Importance of Predation Risk in an Aquatic Food Web

    PubMed Central

    Kwan, Christopher Kent; Sanford, Eric; Long, Jeremy

    2015-01-01

    Although the cascading impact of predators depends critically on the relative role of lethal predation and predation risk, we lack an understanding of how human-caused stressors may shift this balance. Emergent evidence suggests that pollution may increase the importance of predator consumptive effects by weakening the effects of fear perceived by prey. However, this oversimplification ignores the possibility that pollution may also alter predator consumptive effects. In particular, contaminants may impair the consumptive effects of predators by altering density-dependent interactions among prey conspecifics. No study has directly compared predator consumptive and non-consumptive effects in polluted versus non-polluted settings. We addressed this issue by using laboratory mesocosms to examine the impact of sublethal doses of copper on tri-trophic interactions among estuarine predator crabs Cancer productus, carnivorous whelk prey Urosalpinx cinerea, and the basal resource barnacles Balanus glandula. We investigated crab consumptive effects (whelks culled without crab chemical cues), non-consumptive effects (whelks not culled with crab chemical cues), and total effects (whelks culled with crab chemical cues) on whelks in copper polluted and non-polluted waters. Realistic copper concentrations suppressed the effects of simulated crab lethal predation (whelk culling) by removing density-dependent feeding by whelks. Specifically, reductions in conspecific density occurring in elevated copper levels did not trigger the normal increase in whelk consumption rates of barnacles. Weakened effects of fear were only observed at extremely high copper levels, suggesting consumptive effects were more sensitive to pollution. Thus, pollution may shape communities by altering the roles of predators and interactions among prey. PMID:26172044

  7. Copper Pollution Increases the Relative Importance of Predation Risk in an Aquatic Food Web.

    PubMed

    Kwan, Christopher Kent; Sanford, Eric; Long, Jeremy

    2015-01-01

    Although the cascading impact of predators depends critically on the relative role of lethal predation and predation risk, we lack an understanding of how human-caused stressors may shift this balance. Emergent evidence suggests that pollution may increase the importance of predator consumptive effects by weakening the effects of fear perceived by prey. However, this oversimplification ignores the possibility that pollution may also alter predator consumptive effects. In particular, contaminants may impair the consumptive effects of predators by altering density-dependent interactions among prey conspecifics. No study has directly compared predator consumptive and non-consumptive effects in polluted versus non-polluted settings. We addressed this issue by using laboratory mesocosms to examine the impact of sublethal doses of copper on tri-trophic interactions among estuarine predator crabs Cancer productus, carnivorous whelk prey Urosalpinx cinerea, and the basal resource barnacles Balanus glandula. We investigated crab consumptive effects (whelks culled without crab chemical cues), non-consumptive effects (whelks not culled with crab chemical cues), and total effects (whelks culled with crab chemical cues) on whelks in copper polluted and non-polluted waters. Realistic copper concentrations suppressed the effects of simulated crab lethal predation (whelk culling) by removing density-dependent feeding by whelks. Specifically, reductions in conspecific density occurring in elevated copper levels did not trigger the normal increase in whelk consumption rates of barnacles. Weakened effects of fear were only observed at extremely high copper levels, suggesting consumptive effects were more sensitive to pollution. Thus, pollution may shape communities by altering the roles of predators and interactions among prey. PMID:26172044

  8. Exposure to air pollution increases the risk of osteoporosis: a nationwide longitudinal study.

    PubMed

    Chang, Kuang-Hsi; Chang, Mei-Yin; Muo, Chih-Hsin; Wu, Trong-Neng; Hwang, Bing-Fang; Chen, Chiu-Ying; Lin, Tsung-Hsing; Kao, Chia-Hung

    2015-05-01

    Several studies have indicated that air pollution induces systemic as well as tissue-specific inflammation. Chronic inflammatory diseases such as rheumatoid arthritis and chronic obstructive pulmonary disease reduce bone mineral density (BMD), leading to increased release of immune cells from the bone marrow. However, the association between air pollution and osteoporosis remains poorly defined. Therefore, we conducted this population-based retrospective cohort study to evaluate the risk of osteoporosis in Taiwanese residents exposed to air pollution.We combined 2 nationwide databases in this study. The National Health Insurance Research Database of Taiwan was available from 2000 to 2010. Detailed daily data on air pollution were collected by Taiwan Environmental Protection Agency (EPA) from 1998 to 2010. We calculated the yearly average concentrations of air pollutants from the study start to the date of osteoporosis occurrence, or withdrawal from the NHI program, or December 31, 2010. The yearly average concentrations of air pollutants were categorized into quartiles, and the risks of osteoporosis were evaluated among 4 stages of air pollutants.Among Q1, Q2, Q3, and Q4 of pollutants in all subjects, the adjusted hazard ratios (HRs) of osteoporosis in Q2, Q3, and Q4 were compared with Q1. For carbon monoxide (CO), the adjusted HRs were 1.05 (95% confidence interval [CI], 0.97-1.14), 1.78 (95% CI, 1.65-1.92), and 1.84 (95% CI, 1.71-1.98), respectively. For nitrogen dioxide (NO2), the adjusted HRs were 1.35 (95% CI, 1.25-1.45), 1.24 (95% CI, 1.15-1.35), and 1.60 (95% CI, 1.48-1.73), respectively, in all subjects.The findings of the present study show that CO and NO2 exposure is associated with an increased risk of osteoporosis in the Taiwanese population.

  9. The Antarctic Ozone Hole.

    ERIC Educational Resources Information Center

    Stolarski, Richard S.

    1988-01-01

    Discusses the Airborne Antarctic Ozone Experiment (1987) and the findings of the British Antarctic Survey (1985). Proposes two theories for the appearance of the hole in the ozone layer over Antarctica which appears each spring; air pollution and natural atmospheric shifts. Illustrates the mechanics of both. Supports worldwide chlorofluorocarbon…

  10. Importance of NOx control for peak ozone reduction in the Pearl River Delta region

    NASA Astrophysics Data System (ADS)

    Li, Ying; Lau, Alexis K. H.; Fung, Jimmy C. H.; Zheng, Junyu; Liu, Shawchen

    2013-08-01

    As major air pollutants and key precursors of several secondary air pollutants, nitrogen oxide (NOx) emissions are regulated in many countries. However, NOx control increases ozone concentrations when the ozone formation regime is volatile organic compound (VOC) limited. Although many studies have shown that NOx regulation reduces ozone levels over the long term, it is still of concern that NOx regulation increases short-term ozone levels in metropolitan regions, where ozone formation is found to be predominantly VOC-limited. The Pearl River Delta (PRD) in China is such a region. Our modeling sensitivity study shows that while NOx reduction in the PRD region may raise the mean ozone concentration, it can also decrease peak ozone levels. Similar changes are observed in the NOx and ozone data of the PRD regional air quality monitoring network (2006-2012), lending further credence to our results. In the model, this NOx control effect is a result of the complicated spatial and diurnal variations of the ozone formation regime. In most of the PRD region, the formation regime is VOC-limited in the morning and becomes NOx-limited during peak ozone hours. Although some areas are always VOC-limited, their ozone concentrations are relatively low, and the ozone increases caused by NOx reduction generally do not cause higher ozone levels than the region's original ozone maxima. Several control scenarios are simulated to evaluate the effects of various possible control regulations. Our results show that in addition to VOC control, NOx control can be effective for reducing peak ozone concentrations in the PRD region.

  11. GSTM1 modulation of IL-8 expression in human epithelial cells exposed to ozone

    EPA Science Inventory

    Exposure to the major air pollutant ozone can aggravate asthma and other lung diseases. Our recent study in humanvolunteers hasshown that the glutathione S-transferase Mu 1(GSTMI)-null genotype is associated with increased airway neutrophilic inflammation induced by inhaled ozone...

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

    PubMed

    Preisler, Haiganoush K; Zhong, Shiyuan Sharon; Esperanza, Annie; Brown, Timothy J; Bytnerowicz, Andrzej; Tarnay, Leland

    2010-03-01

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

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

    PubMed

    Preisler, Haiganoush K; Zhong, Shiyuan Sharon; Esperanza, Annie; Brown, Timothy J; Bytnerowicz, Andrzej; Tarnay, Leland

    2010-03-01

    Data from four continuous ozone and weather monitoring sites operated by the National Park Service in Sierra Nevada, California, are used to develop an ozone forecasting model and to estimate the contribution of wildland fires on ambient ozone levels. The analyses of weather and ozone data pointed to the transport of ozone precursors from the Central Valley as an important source of pollution in these National Parks. Comparisons of forecasted and observed values demonstrated that accurate forecasts of next-day hourly ozone levels may be achieved by using a time series model with historic averages, expected local weather and modeled PM values as explanatory variables. Results on fire smoke influence indicated occurrence of significant increases in average ozone levels with increasing fire activity. The overall effect on diurnal ozone values, however, was small when compared with the amount of variability attributed to sources other than fire. PMID:19914752

  14. Ozone - Current Air Quality Index

    MedlinePlus

    ... reducing exposure to extremely high levels of particle pollution is available here . Fires: Current Conditions Click to ... Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke from fires | What You Can Do Health ...

  15. Reforming agricultural nonpoint pollution policy in an increasingly budget-constrained environment.

    PubMed

    Shortle, James S; Ribaudo, Marc; Horan, Richard D; Blandford, David

    2012-02-01

    Agricultural nonpoint source water pollution has long been recognized as an important contributor to U.S. water quality problems and the subject of an array of local, state, and federal initiatives to reduce the problem. A "pay-the-polluter" approach to getting farmers to adopt best management practices has not succeeded in improving water quality in many impaired watersheds. With the prospects of reduced funding for the types of financial and technical assistance programs that have been the mainstay of agricultural water quality policy, alternative approaches need to be considered. Some changes to the way current conservation programs are implemented could increase their efficiency, but there are limits to how effective a purely voluntary approach can be. An alternative paradigm is the "polluter pays" approach, which has been successfully employed to reduce point source pollution. A wholesale implementation of the polluter-pays approach to agriculture is likely infeasible, but elements of the polluter-pays approach could be incorporated into agricultural water quality policy.

  16. Terminating pre-ozonation prior to biological activated carbon filtration results in increased formation of nitrogenous disinfection by-products upon subsequent chlorination.

    PubMed

    Chu, Wenhai; Li, Changjun; Gao, Naiyun; Templeton, Michael R; Zhang, Yanshen

    2015-02-01

    Previous research demonstrated that ozone dosed before biological activated carbon (BAC) filtration reduces the formation of disinfection by-products (DBPs) upon subsequent chlorination. The current work aimed to evaluate the impact of terminating this pre-ozonation on the ability of the BAC to remove the precursors of N-DBPs. More N-DBP precursors passed into the post-BAC water when the pre-ozonation was terminated, resulting in greater formation of N-DBPs when the water was subsequently chlorinated, compared to a parallel BAC filter when the pre-ozonation was run continuously. Moreover, the N-DBP formation potential was significantly increased in the effluent of the BAC filter after terminating pre-ozonation, compared with the influent of the BAC filter (i.e. the effluent from the sand filter). Therefore, while selectively switching pre-ozonation on/off may have cost and other operational benefits for water suppliers, these should be weighed against the increased formation of N-DBPs and potential associated health risks.

  17. Ozone variability

    NASA Astrophysics Data System (ADS)

    Duetsch, H. U.

    1983-09-01

    The annual and long-term variations in the atmospheric ozone layer were examined on the basis of 55 yr of data taken at Aroya, Switzerland and 25 yr of data gathered by the global ozone network. Attention was given to annual and biennial variations, which showed that the midlatitude peak concentration was affected by a quasi-biennial variation of the tropical stratospheric circulation. Smaller scale circulation patterns were dominant in the lower stratosphere, although an observed negative trend of the total ozone was equally distributed between the troposphere and 24 km altitude. The global ozone increase detected in the 1960s was possible due to general circulation alterations, but may also have been influenced by injection of NO(x) into the atmosphere during atomic bomb testing.

  18. Pollution

    ERIC Educational Resources Information Center

    Rowbotham, N.

    1973-01-01

    Presents the material given in one class period in a course on Environmental Studies at Chesterfield School, England. The topics covered include air pollution, water pollution, fertilizers, and insecticides. (JR)

  19. Pollution

    ERIC Educational Resources Information Center

    Terry, Luther L.

    1970-01-01

    Our mechanized environment has produced a variety of man-made pollutants. Prevention of pollution and resulting health hazards is a primary challenge. The Federal Government undertakes a large responsibility in the field of environmental control. (CK)

  20. Quantification of relative contribution of Antarctic ozone depletion to increased austral extratropical precipitation during 1979-2013

    NASA Astrophysics Data System (ADS)

    Bai, Kaixu; Chang, Ni-Bin; Gao, Wei

    2016-02-01

    Attributing the observed climate changes to relevant forcing factors is critical to predicting future climate change scenarios. Precipitation observations in the Southern Hemisphere indicate an apparent moistening pattern over the extratropics during the time period 1979 to 2013. To investigate the predominant forcing factor in triggering such an observed wetting climate pattern, precipitation responses to four climatic forcing factors, including Antarctic ozone, water vapor, sea surface temperature (SST), and carbon dioxide, were assessed quantitatively in sequence through an inductive approach. Coupled time-space patterns between the observed austral extratropical precipitation and each climatic forcing factor were firstly diagnosed by using the maximum covariance analysis (MCA). With the derived time series from each coupled MCA modes, statistical relationships were established between extratropical precipitation variations and each climatic forcing factor by using the extreme learning machine. Based on these established statistical relationships, sensitivity tests were conducted to estimate precipitation responses to each climatic forcing factor quantitatively. Quantified differential contribution with respect to those climatic forcing factors may explain why the observed austral extratropical moistening pattern is primarily driven by the Antarctic ozone depletion, while mildly modulated by the cooling effect of equatorial Pacific SST and the increased greenhouse gases, respectively.

  1. Tropical Tropospheric Ozone and Smoke Interactions: Satellite Observations During the 1997 Indonesian Fires

    NASA Technical Reports Server (NTRS)

    Thompson, A. M.; Witte, J. C.; Herman, J. R.; Hudson, R. D.; Frolov, A. D.; Kochhar, A. K.; Fujiwara, M.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Biomass burning generates hydrocarbons, nitrogen oxides and carbon monoxide that lead to tropospheric ozone pollution. Other combustion products form soot and various aerosol particles that make up smoke. Since early 1997 smoke and tropospheric ozone have been monitored in real-time from TOMS (Total Ozone Mapping Spectrometer) at toms.gsfc.nasa.gov (smoke aerosol) and metosrv2.umd.edu/-tropo (tropospheric ozone). The striking increase in smoke and tropospheric ozone observed during the 1997 Indonesian fires was the first extreme episode observed. During the August-November period, plumes of excess ozone and smoke coincided at times but were decoupled at other times, a phenomenon followed with trajectories. Thus, trans-boundary evolution of smoke and ozone differed greatly. The second discovery of the 1997 TOMS record was a dynamical interaction of ozone with the strong El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) that led to a jump in tropospheric ozone in March 1997 over the entire Indian Ocean, well ahead of the intense burning period. A climatology of smoke and tropospheric ozone from a 1980's TOMS instrument shows offsets in the timing of these pollutants - further evidence that factors other than biomass burning exert a strong influence on tropical tropospheric ozone.

  2. Surface ozone measurements using differential absorption lidar

    NASA Astrophysics Data System (ADS)

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

    2005-01-01

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

  3. Air Pollution

    MedlinePlus

    ... tobacco smoke. How is air pollution linked to climate change? While climate change is a global process, it ... ozone levels are also a concern. Impacts of Climate Change on Human Health in the United States: A ...

  4. Surface Ozone in Kiev

    NASA Astrophysics Data System (ADS)

    Shavrina, A. V.; Mikulskaya, I. A.; Kiforenko, S. I.; Blum, O. B.; Sheminova, V. A.; Veles, A. A.

    The study of total ozone over Kiev and its concentration changes with height in the troposphere has been made on the base of ground-based observations with the infrared Fourier-spectrometer in the Main Astronomical Observatory of National Academy of Sciences of Ukraine (MAO NASU) as part of ESA-NIVR-KNMI project no 2907 "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles "(2005-2008) [1,2,4]. Ground-level ozone in Kiev for an episode of its high concentrations in August 2000 was also simulated with the model of urban air pollution UAM-V [5,6]. In 2008 the satellite data Aura-OMI on profiles of ozone in the atmosphere OMO3PR became available (http://disc.sci.gsfc.nasa.gov/ Aura/data-holdings/OMI/ omo3pr_v003.shtml). They include ozone content in the lower layer of the atmosphere, beginning from 2005, which can be used to evaluate the ground-level ozone in all cities of Ukraine. The comparison of the data of ozone air pollution in Kiev (ozone - the pollutant of the first class of danger) and medical statistics data of of respiratory system (RS) diseases of the city population was carried out with the package "Statistica". A regression analysis, prognostic regression modelling, and retrospective prognosis of the epidemiological situation with respect to RS pathologies in Kiev in 2000-2006 were performed.

  5. Analysis of the Impact of Wildfire on Surface Ozone Record in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Oltmans, S. J.; Pierce, R. B.; Sullivan, J. T.; Reddy, P. J.

    2015-12-01

    Ozone plays an important role on the oxidation capacity of the atmosphere, and at ground-level has negative impacts on human health and ecosystem processes. In order to understand the dynamics and variability of surface ozone, it is imperative to analyze individual sources, interactions between sources, transport, and chemical processes of ozone production and accumulation. Biomass burning and wildfires have been known to emit a suite of particulate matter and gaseous compounds into the atmosphere. These compounds, such as, volatile organic compounds, carbon monoxide, and nitrogen oxides are precursor species which aid in the photochemical production and destruction of ozone. The Colorado Front Range (CFR) is a region of complex interactions between pollutant sources and meteorological conditions which result in the accumulation of ozone. High ozone events in the CFR associated with fires are analyzed for 2003-2014 to develop understanding of the large scale influence and variability of ozone and wildfire relationships. This study provides analysis of the frequency of enhanced ozone episodes that can be confirmed to be transported within and affected by the fires and smoke plumes. Long-term records of surface ozone data from the CFR provide information on the impact of wildfire pollutants on seasonal and diurnal ozone behavior. Years with increased local fire activity, as well as years with increased long-range transport of smoke plumes, are evaluated for the effect on the long-term record and high ozone frequency of each location. Meteorological data, MODIS Fire detection images, NOAA HYSPLIT Back Trajectory analysis, NOAA Smoke verification model, Fire Tracer Data (K+), RAQMS Model, Carbon Monoxide data, and Aerosol optical depth retrievals are used with NOAA Global Monitoring Division surface ozone data from three sites in Colorado. This allows for investigation of the interactions between pollutants and meteorology which result in high surface ozone levels.

  6. Distinctive timing of U.S. historical ozone change determined by climate and anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Yan, Y.; Lin, J.; He, C.

    2015-12-01

    The ground-level ozone over the United States is known to have been influenced by historical climate change and anthropogenic precursor emissions, whereas their individual contributions and the associated mechanisms of influence remain less understood. Here we analyze 25-year (1990-2014) annual mean ground-level ozone across the U.S. Empirical Orthogonal Function (EOF) and linear fitting show that ozone has experienced a notable rate of growth at 0.13 ppb/yr averaged over U.S. About 74% of this growth is attributed to enhancement in nighttime ozone (at 0.19 ppb/yr), with the remaining 26% due to daytime ozone increase (at 0.07 ppb/yr). To relate ozone interannual variations to climate change, we employ the Atlantic Multi-decadal Oscillation (AMO) and Southern Oscillation (SO) indices to infer the states of climate over the U.S. We find large correlations between ozone interannual variability and these climate indices: 0.65 for SO index, 0.73 for AMO index, and 0.82 for their combined index. The correlations are much higher (0.69, 0.78 and 0.86) for daytime ozone. Sensitivity simulations conducted with the GEOS-Chem chemical transport model reveal that climate variability has determined ozone interannual variability, particularly for daytime ozone, while anthropogenic emissions reductions have particularly driven the growth in nighttime ozone. These results better connect ozone air pollution with human activity and climate change. Figure. Slopes for the linear fitting analyse of the ground-level ozone variations on the inter-annual timescale for AQS measurements during 1990-2014 (a) for daytime ozone and (b) for nighttime ozone. Also shown are the slopes for interannual variation during 2004-2011 (c) for daytime ozone and (d) for nighttime ozone.

  7. Surface ozone pollution in Poland - observations and modelling support for a two-year assessment 2012-2013

    NASA Astrophysics Data System (ADS)

    Struzewska, Joanna; Kaminski, Jacek W.; Durka, Pawel

    2015-04-01

    The concentrations of near-surface ozone in terms of long term objectives and target values are exceeded at many monitoring sites in Poland. At the request of the Chief Inspectorate of Environmental Protection, an assessment of ozone impact on human health and ecosystems in Poland was undertaken, based on the GEM-AQ model calculations for the period 2012-2013. GEM-AQ (Kaminski et al., 2008) is a comprehensive chemical weather model where air quality processes (chemistry and aerosols) are implemented on-line in the operational weather prediction model developed at Environment Canada (Cote et al., 1998). For this project the model was run in a self-nesting mode with the target grid centered over Poland with the resolution of 5 km. The EMEP emission inventory was refined based on GIS information. Modelling results were evaluated against ozone and NO2 measurements from available monitoring stations in Poland using the DeltaTool developed in the scope of FAIRMODE. We will present exposure levels to high ozone concentrations in terms of number of days with exceeded target values as well as indices AOT40 and SOMO35. Differences between exposure diagnostics in 2012 and 2013 will be discussed.

  8. On the role of climate variability on tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Lin, M.

    2014-12-01

    The response of tropospheric ozone to changing atmospheric circulation is poorly understood owing to a lack of reliable long-term observations. There is great current interest in quantifying the extent to which observed ozone trends over recent decades at northern mid-latitude sites are driven by changes in precursor emissions versus shifts in atmospheric circulation patterns. In this talk, I present a detailed analysis of the impact of interannual to decadal climate variability on tropospheric ozone, based on observations and a suite of chemistry-climate model hindcast simulations. Decadal shifts in circulation regimes modulate long-range transport of Asian pollution, leading to very different seasonal ozone trends at Mauna Loa Observatory in the subtropical Pacific Ocean. During autumn, the flow of ozone-rich air from Eurasia towards Hawaii strengthened in the mid-1990s onwards, as a result of the positive phase of the Pacific North American pattern, increasing ozone at Mauna Loa. During spring, weakening airflow from Asia in the 2000s, tied to La-Niña-like decadal cooling in the equatorial Pacific Ocean, offsets ozone increases at Mauna Loa that otherwise would have occurred due to rising Asian emissions. The circulation-driven variability in Asian pollution over the subtropical North Pacific regions manifests mainly as changes in the mean as opposed to in transport events. At high-elevation Western U.S. sites, intrusions of stratospheric ozone deep into the troposphere during spring exert a greater influence than Asian pollution, particularly on the high tail of observed surface ozone distribution. We show that year-to-year variability in springtime high-ozone episodes measured in Western U.S. surface air is tied to known modes of climate variability, which modulate meanders in the polar frontal jet conducive to deep stratospheric ozone intrusions. Specifically, the La Niña-related increase in the frequency of deep stratospheric intrusion events plays a

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

    PubMed

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

    2013-11-01

    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.

  10. An improved tropospheric ozone database retrieved from SCIAMACHY Limb-Nadir-Matching method

    NASA Astrophysics Data System (ADS)

    Jia, Jia; Rozanov, Alexei; Ladstätter-Weißenmayer, Annette; Ebojie, Felix; Rahpoe, Nabiz; Bötel, Stefan; Burrows, John

    2015-04-01

    Tropospheric ozone is one of the most important green-house gases and the main component of photochemical smog. It is either transported from the stratosphere or photochemically produced during pollution events in the troposphere that threaten the respiratory system. To investigate sources, transport mechanisms of tropospheric ozone in a global view, limb nadir matching (LNM) technique applied with SCIAMACHY instrument is used to retrieve tropospheric ozone. With the fact that 90% ozone is located in the stratosphere and only about 10% can be observed in the troposphere, the usage of satellite data requires highly qualified nadir and limb data. In this study we show an improvement of SCIAMACHY limb data as well as its influence on tropospheric ozone results. The limb nadir matching technique is also refined to increase the quality of the tropospheric ozone. The results are validated with ozone sonde measurements.

  11. Effect of ozone on respiratory responses in subjects with asthma

    SciTech Connect

    Koenig, J.Q.

    1995-03-01

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

  12. Ozone-induced increases in substance P and 8-epi-prostaglandin F2 alpha in the airways of human subjects

    SciTech Connect

    Hazbun, M.E.; Hamilton, R.; Holian, A.; Eschenbacher, W.L. )

    1993-11-01

    We are interested in the mechanisms of ozone-induced lung effects after short-term exposure and the relationship with subsequent pulmonary inflammation and disease. Our hypothesis is that ozone, as a powerful oxidant, will diminish the activity of neutral endopeptidase (NEP) in the airways of humans with resulting increased concentrations of neuropeptides such as substance P (SP). We have exposed seven (two women, five men) healthy, nonsmoking individuals (22 to 30 yr of age) to filtered air and ozone (0.25 ppm) for 1 h in an environmental chamber during heavy exercise. Bronchoscopy with airway lavage (AL) and bronchoalveolar lavage (BAL) was performed immediately after ozone exposure. The lavage samples were analyzed by enzyme immunoassay for SP and 8-epi-prostaglandin F2 alpha (8-epi-PGF2 alpha) (a marker for oxidative free radical reaction) and by radioimmunoassay for complement fragments. FEV1 had declined 12.4 +/- 1.9% (mean +/- SEM) as a result of ozone exposure. The AL concentration for SP and 8-epi-PGF2 alpha and BAL concentration of C3a after ozone exposure were significantly higher than after the filtered air exposure (P < 0.05). There was a significant correlation between SP and 8-epi-PGF2 alpha concentrations in the AL fluid (r2 = 0.89 and P < 0.05). There were no changes in C5a in either compartment or any of the mediators in the plasma samples. These results extend previous results from animal studies suggesting that ozone's mechanism of action is through an oxidative reaction resulting in a decreased activity of NEP in the airways with a subsequent increase in the concentration and activity of SP.

  13. Ozone risk for crops and pastures in present and future climates

    NASA Astrophysics Data System (ADS)

    Fuhrer, Jürg

    2009-02-01

    Ozone is the most important regional-scale air pollutant causing risks for vegetation and human health in many parts of the world. Ozone impacts on yield and quality of crops and pastures depend on precursor emissions, atmospheric transport and leaf uptake and on the plant’s biochemical defence capacity, all of which are influenced by changing climatic conditions, increasing atmospheric CO2 and altered emission patterns. In this article, recent findings about ozone effects under current conditions and trends in regional ozone levels and in climatic factors affecting the plant’s sensitivity to ozone are reviewed in order to assess implications of these developments for future regional ozone risks. Based on pessimistic IPCC emission scenarios for many cropland regions elevated mean ozone levels in surface air are projected for 2050 and beyond as a result of both increasing emissions and positive effects of climate change on ozone formation and higher cumulative ozone exposure during an extended growing season resulting from increasing length and frequency of ozone episodes. At the same time, crop sensitivity may decline in areas where warming is accompanied by drying, such as southern and central Europe, in contrast to areas at higher latitudes where rapid warming is projected to occur in the absence of declining air and soil moisture. In regions with rapid industrialisation and population growth and with little regulatory action, ozone risks are projected to increase most dramatically, thus causing negative impacts major staple crops such as rice and wheat and, consequently, on food security. Crop improvement may be a way to increase crop cross-tolerance to co-occurring stresses from heat, drought and ozone. However, the review reveals that besides uncertainties in climate projections, parameters in models for ozone risk assessment are also uncertain and model improvements are necessary to better define specific targets for crop improvements, to identify regions

  14. [Ozone exposure and asthma].

    PubMed

    Kleis, S; Louis, R; Bartsch, P

    2003-03-01

    Ozone is a pollutant the production of which depends on weather conditions and car engine combustion. Numerous epidemiological studies have indicated that high ozone levels correlated with morbidity in asthma. Experimental studies have shown that exposure of healthy subjects and asthmatics to ozone levels comparable to those measured in ambient air during hot summer days can generate respiratory symptoms, neutrophilic airways inflammation and lung function impairment. Lung function changes following ozone exposure are more pronounced in asthmatics and are dependent on the duration and intensity of exposure, a previous exposure and the nutritional status of the subjects. The airway epithelial cell layer is likely to play a pivotal role in initiating the inflammatory process following ozone exposure. Control of ambient air ozone levels must be a target for public health authorities.

  15. Biological effects of ozone

    SciTech Connect

    Lippmann, M. )

    1989-09-01

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

  16. Lower Boundary Layer and Ozone Profiles Over Fresno during Wildfire Events

    NASA Astrophysics Data System (ADS)

    Ogunjemiyo, S. O.; Omolayo, S. A.

    2010-12-01

    Ozone is a secondary pollutant in the troposphere that is largely formed as a result of photolytic reactions related to ozone precursors such as methane (CH4), carbon monoxide (CO), nitrogen oxides (NOx) and VOCs (Volatile Organic Compounds like isoprene, benzene etc.). Hence, processes and factors regulating emissions of ozone precursors are important in controlling spatial and temporal variation of ozone concentrations. Giving favorable meteorological conditions, large scale wildfires in fuel rich areas have been recognized for their potential to significantly affect the regional and global distributions of tropospheric O3, and also increases the background surface ozone concentrations above the NAAQS level, even in areas that may be hundreds of miles away from wildfire locations. Improving regional ozone forecast thus requires not only the knowledge of the amount of ozone precursors released into the atmosphere and ozone produced during wildfires, but also information on boundary layer dynamics and vertical ozone transport. In this study effort is made to characterize ozone transport in the lower urban boundary layer during wildfire events. In this regard, tethersonde and ozonesonde measurements were made over Fresno California in the period the region was affected by smoke particles from the Moonlight fire in September 2007 and the Telegraph fire in July 2008. Analysis of the profiles data showed that the Fresno Eddy, in addition to boundary layer dynamics, particularly the down mixing of high ozone concentration in the residual boundary layer, were significant factors influencing hourly measured ground level ozone concentration at the site.

  17. [Influence of ozone on snap bean under ambient air in two sites of northern China].

    PubMed

    Yuan, Xiang-Yang; Zhang, Wei-Wei; Sun, Jing-Song; Hu, En-Zhu; Zhang, Yu-Long; Zhang, Hong-Xing; Tian, Yuan; Feng, Zhao-Zhong

    2014-08-01

    Tropospheric ozone (O3) has been assumed the most phytotoxic air pollutant and the snap bean (Phaseolus vulgaris L.) is known to be an ozone-sensitive species. Two genotypes (R123, ozone-tolerance, S156, ozone-sensitivity) of snap bean were explored in three places. The objective of this study was to evaluate whether the snap bean was influenced under the current ambient ozone concentration. The findings indicated that the leaves of bean grown at Research Center for Eco-Environmental Sciences (RCEES), Chinese Academy of Sciences and ChangPing showed visible ozone symptoms under the ambient ozone concentration, and the averaged ozone injury proportion in S156 was 23.5% higher than R123 during the entire growth season. The ozone damage to the snap bean depends on the plant growing stages. The injury symptoms appeared just after flowering, increased from the stages of flowering to pod formation, and reached the maximum at the stages of pod maturation. The ratio of S156/R123 in pod yield was 0.48, and 0.24 and 0.73 in the RCEES, ChangPing and Harbin, respectively. The ratio close to 1 was assumed that the plant growth is not affected by ozone, and the lower ratio is, the more damage caused by ozone. Obviously, the current ambient ozone concentration of Beijing area has significantly caused the yield loss of snap bean.

  18. Impact of diatomite on the slightly polluted algae-containing raw water treatment process using ozone oxidation coupled with polyaluminum chloride coagulation.

    PubMed

    Hu, Wenchao; Wu, Chunde; Jia, Aiyin; Zhang, Zhilin; Chen, Fang

    2014-01-01

    The impact of adding diatomite on the treatment performance of slightly polluted algae-containing raw water using ozone pre-oxidation and polyaluminum chloride (PAC) coagulation was investigated. Results demonstrated that the addition of diatomite is advantageous due to reduction of the PAC dose (58.33%) and improvement of the removal efficiency of algae, turbidity, and dissolved organic matter (DOM) in raw water. When the ozone concentration was 1.0 mg L⁻¹ and the PAC dosage was 2.5 mg L⁻¹, the removal rates of algae, turbidity, UV254, and TOC were improved by 6.39%, 7.06%, 6.76%, and 4.03%, respectively, with the addition of 0.4 g L⁻¹ diatomite. It has been found that the DOM presented in the Pearl River raw water mainly consisted of small molecules (<1 kDa) and large ones (> 50 kDa). After adding diatomite (0.4 g L⁻¹), the additional removal of 5.77% TOC and 14.82% UV254 for small molecules (<1 kDa) of DOM, and 8.62% TOC and 7.33% UV254 for large ones (>50 kDa) could be achieved, respectively, at an ozone concentration of 1.0 mg L⁻¹ and a PAC dose of 2.5 mg L⁻¹. The growth of anabaena flos-aquae (A.F.) was observed by an atomic force microscope (AFM) before and after adding diatomite. AFM images demonstrate that diatomite may have a certain adsorption on A.F.

  19. Association of ozone and particulate air pollution with out-of-hospital cardiac arrest in Helsinki, Finland: evidence for two different etiologies.

    PubMed

    Rosenthal, Frank S; Kuisma, Markku; Lanki, Timo; Hussein, Tareq; Boyd, James; Halonen, Jaana I; Pekkanen, Juha

    2013-01-01

    Out-of-hospital cardiac arrest (OHCA) has been previously associated with exposure to particulate air pollution. However, there is uncertainty about the agents and mechanisms that are involved. We aimed to determine the association of gases and particulates with OHCA, and differences in pollutant effects on OHCAs due to acute myocardial infarction (AMI) vs those due to other causes. Helsinki Emergency Medical Services provided data on OHCAs of cardiac origin (OHCA_Cardiac). Hospital and autopsy reports determined whether OHCAs were due to AMI (OHCA_MI) or other cardiac causes (OHCA_Other). Pollutant data was obtained from central ambient monitors. A case-crossover analysis determined odds ratios (ORs) for hourly lagged exposures (Lag 0-3) and daily lagged exposures (Lag 0d-3d), expressed per interquartile range of pollutant level. For OHCA_Cardiac, elevated ORs were found for PM(2.5) (Lag 0, 1.07; 95% confidence interval (CI): 1.01-1.13) and ozone (O(3)) (Lag 2d, 1.18; CI: 1.03-1.35). For OHCA_MI, elevated ORs were found for PM(2.5) (Lag 0, 1.14; CI: 1.03-1.27; Lag 0d, 1.17; CI: 1.03-1.33), accumulation mode particulate (Acc) (Lag 0d, 1.19; CI: 1.04-1.35), NO (Lag 0d, 1.07; CI: 1.01-1.13), and ultrafine particulate (Lag 0d, 1.27; CI: 1.05-1.54). For OHCA_Other, elevated ORs were found only for O(3) (Lag 1d, 1.26; CI: 1.07-1.48; Lag 2d, 1.30; CI: 1.11-1.53). Results from two-pollutant models, with one of the pollutants either PM(2.5) or O(3), suggested that associations were primarily due to effects of PM(2.5) and O(3), rather than other pollutants. The results suggest that air pollution triggers OHCA via two distinct modes: one associated with particulates leading to AMI and one associated with O(3) involving etiologies other than AMI, for example, arrhythmias or respiratory insufficiency.

  20. Tracking the sources of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.; Churkina, G.; Coates, J.; Grote, R.; Mar, K.; von Schneidemesser, E.; Zhu, S.

    2013-12-01

    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 set of studies we examine the attribution of tropospheric ozone to emissions of VOC using a tagging approach, whereby each VOC oxidation intermediate in model chemical mechanisms is tagged with the identity of its primary emitted compound, allowing modelled ozone production to be directly attributed to all emitted VOCs in the model. Using a global model we

  1. Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000

    SciTech Connect

    Massie, Steven T.; Torres, O.; Smith, Steven J.

    2004-12-01

    Emission inventories indicate that the largest increases in SO{sub 2} emissions have occurred in Asia during the last 20 years. By inference, largest increases in aerosol, produced primarily by the conversion of SO{sub 2} to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1{sup o} by 1{sup o} global grid. The anthropogenic component of the TOMS aerosol record is maximized by examining the seasonal cycles of desert dust and Boreal fire smoke, and identifying the months of the year for which the desert dust and Boreal fire smoke are least conspicuous. Gobi and Taklimakan desert dust in Asia is prevalent in the TOMS record during spring, and eastern Siberian smoke from Boreal forest fires is prevalent during summer. Aerosol trends are calculated on a regional basis during winter (November-February) to maximize the anthropogenic component of the aerosol record. Large increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges river basin in India. Aerosol increased by 17% per decade during winter over the China coastal plain, while SO{sub 2} emissions over the same geographical region increased by 33% per decade.

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

    PubMed

    Reich, P B; Amundson, R G

    1985-11-01

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

  3. Ambient Levels of Ozone Reduce Net Photosynthesis in Tree and Crop Species

    NASA Astrophysics Data System (ADS)

    Reich, Peter B.; Amundson, Robert G.

    1985-11-01

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

  4. Immunosuppression of pulmonary natural killer activity by exposure to ozone

    SciTech Connect

    Burleson, G.R.; Keyes, L.L.; Stutzman, J.D. )

    1989-01-01

    Ozone is an oxidant gas and an ubiquitous oxidant air pollutant with the potential to adversely affect pulmonary immune function with a consequent increase in disease susceptibility. Pulmonary natural killer (NK) activity was measured in order to assess the pulmonary immunotoxicity of continuous ozone exposure. Continuous ozone exposures at 1.0 ppm were performed for 23.5 hours per day for either 1, 5, 7, or 10 consecutive days. Pulmonary immune function was assessed by measuring natural killer (NK) activity from whole-lung homogenates of male Fischer-344 rats. Results of this study indicated that continuous ozone exposure for 1, 5, or 7 days resulted in a significant decrease in pulmonary NK activity. This suppressed pulmonary NK activity returned to control levels after continuous exposure to ozone for 10 days. The suppressed pulmonary NK response was thus attenuated and returned to normal values in the continued presence of ozone gas. This attenuation process is dynamic, complex, and doubtless involves several cell types and/or products of these cells. Pulmonary NK activity was also suppressed at 0.5 ppm ozone, but not at 0.1 ppm ozone, following 23.5 hours of exposure. NK activity is important for defense against viral, bacterial, and neoplastic disease. The depressed NK activity resulting from continuous ozone exposure could therefore result in a compromised ability to defend against pulmonary diseases.

  5. Progress in Assessing Air Pollutant Risks from In Vitro Exposures: Matching Ozone Dose and Effect in Human Air Way Cells

    EPA Science Inventory

    In vitro exposures to air pollutants could, in theory, facilitate a rapid and detailed assessment of molecular mechanisms of toxicity. However, it is difficult to ensure that the dose of a gaseous pollutant to cells in tissue culture is similar to that of the same cells during in...

  6. Fine particulate matter pollution linked to respiratory illness in infants and increased hospital costs.

    PubMed

    Sheffield, Perry; Roy, Angkana; Wong, Kendrew; Trasande, Leonardo

    2011-05-01

    There has been little research to date on the linkages between air pollution and infectious respiratory illness in children, and the resulting health care costs. In this study we used data on air pollutants and national hospitalizations to study the relationship between fine particulate air pollution and health care charges and costs for the treatment of bronchiolitis, an acute viral infection of the lungs. We found that as the average exposure to fine particulate matter over the lifetime of an infant increased, so did costs for the child's health care. If the United States were to reduce levels of fine particulate matter to 7 percent below the current annual standard, the nation could save $15 million annually in reduced health care costs from hospitalizations of children with bronchiolitis living in urban areas. These findings reinforce the need for ongoing efforts to reduce levels of air pollutants. They should trigger additional investigation to determine if the current standards for fine-particulate matter are sufficiently protective of children's health.

  7. Increased chromatin fragmentation and reduced acrosome integrity in spermatozoa of red deer from lead polluted sites.

    PubMed

    Castellanos, Pilar; del Olmo, Enrique; Fernández-Santos, M Rocío; Rodríguez-Estival, Jaime; Garde, J Julián; Mateo, Rafael

    2015-02-01

    Vertebrates are constantly exposed to a diffuse pollution of heavy metals existing in the environment, but in some cases, the proximity to emission sources like mining activity increases the risk of developing adverse effects of these pollutants. Here we have studied lead (Pb) levels in spermatozoa and testis, and chromatin damage and levels of endogenous antioxidant activity in spermatozoa of red deer (Cervus elaphus) from a Pb mining area (n=37) and a control area (n=26). Deer from the Pb-polluted area showed higher Pb levels in testis parenchyma, epididymal cauda and spermatozoa, lower values of acrosome integrity, higher activity of glutathione peroxidase (GPx) and higher values of DNA fragmentation (X-DFI) and stainability (HDS) in sperm than in the control area. These results indicate that mining pollution can produce damage on chromatin and membrane spermatozoa in wildlife. The study of chromatin fragmentation has not been studied before in spermatozoa of wildlife species, and the sperm chromatin structure assay (SCSA) has been revealed as a successful tool for this purpose in species in which the amount of sperm that can be collected is very limited.

  8. Increasing levels and biomagnification of persistent organic pollutants (POPs) in Antarctic biota.

    PubMed

    Goerke, Helmut; Weber, Kurt; Bornemann, Horst; Ramdohr, Sven; Plötz, Joachim

    2004-02-01

    Representatives of the Antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around Elephant Island and from the Weddell Sea were analysed for the most recalcitrant organochlorine compounds. Due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (Gobionotothen gibberifrons, Chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while a benthopelagic species (Champsocephalus gunnari) feeding on krill did not. In the pelagic food chain, lipid normalised concentrations of all compounds increased from Antarctic krill to fish proving that biomagnification of highly lipophilic pollutants (log octanol-water partition coefficient>5) occurs in water-breathing animals. As top predators Weddell and southern elephant seals (Leptonychotes weddellii, Mirounga leonina) biomagnified the persistent organic pollutants relative to krill 30-160 fold with the exception of hexachlorobenzene, the levels of which were lower than in fish indicating its intense specific elimination.

  9. Projecting policy-relevant metrics for high summertime ozone pollution events over the eastern United States due to climate and emission changes during the 21st century

    NASA Astrophysics Data System (ADS)

    Rieder, Harald E.; Fiore, Arlene M.; Horowitz, Larry W.; Naik, Vaishali

    2015-01-01

    the eastern United States (EUS), nitrogen oxides (NOx) emission controls have led to improved air quality over the past two decades, but concerns have been raised that climate warming may offset some of these gains. Here we analyze the effect of changing emissions and climate, in isolation and combination, on EUS summertime surface ozone (O3) over the recent past and the 21st century in an ensemble of simulations performed with the Geophysical Fluid Dynamics Laboratory CM3 chemistry-climate model. The simulated summertime EUS O3 is biased high but captures the structure of observed changes in regional O3 distributions following NOx emission reductions. We introduce a statistical bias correction, which allows derivation of policy-relevant statistics by assuming a stationary mean state bias in the model, but accurate simulation of changes at each quantile of the distribution. We contrast two different 21st century scenarios: (i) representative concentration pathway (RCP) 4.5 and (ii) simulations with well-mixed greenhouse gases (WMGG) following RCP4.5 but with emissions of air pollutants and precursors held fixed at 2005 levels (RCP4.5_WMGG). We find under RCP4.5 no exceedance of maximum daily 8 hour average ozone above 75 ppb by mid-21st century, reflecting the U.S. NOx emissions reductions projected in RCP4.5, while more than half of the EUS exceeds this level by the end of the 21st century under RCP4.5_WMGG. Further, we find a simple relationship between the changes in estimated 1 year return levels and regional NOx emission changes, implying that our results can be generalized to estimate changes in the frequency of EUS pollution events under different regional NOx emission scenarios.

  10. Air pollution problem in the Mexico City metropolitan zone: Photochemical pollution

    SciTech Connect

    Alvarez, H.B.; Alvarez, P.S.; Echeverria, R.S.; Jardon, R.T.

    1997-12-31

    Mexico City Metropolitan Zone (MCMZ) represents an example of a megacity where the air pollution problem has reached an important evolution in a very short time, causing a risk in the health of a population of more than 20 million inhabitants. The atmospheric pollution problem in the MCMZ, began several decades ago, but it increased drastically in the middle of the 80`s. It is important to recognize that in the 60`s, 70`s and the first half of the 80`s the main pollutants were sulfur dioxide and total suspended particles. However since the second half of the 80`s until now, ozone is the most important air pollutant besides of the suspended particles (PM{sub 10}) and other toxic pollutants (1--8). The purpose of this paper is to discuss the evolution of the ozone atmospheric pollution problem in the MCMZ, as well as to analyze the results of several implemented air pollution control strategies.

  11. Biochemical Plant Responses to Ozone 1

    PubMed Central

    Langebartels, Christian; Kerner, Kristina; Leonardi, Silvio; Schraudner, Martina; Trost, Monika; Heller, Werner; Sandermann, Heinrich

    1991-01-01

    Polyamine metabolism was examined in tobacco (Nicotiana tabacum L.) exposed to a single ozone treatment (5 or 7 hours) and then postcultivated in pollutant-free air. The levels of free and conjugated putrescine were rapidly increased in the ozone-tolerant cultivar Bel B and remained high for 3 days. This accumulation was preceded by a transient rise of l-arginine decar-boxylase (ADC, EC 4.1.1.19) activity. The ozone-sensitive cultivar Bel W3 showed a rapid production of ethylene and high levels of 1-aminocyclopropane-1-carboxylic acid after 1 to 2 hours of exposure. Induction of putrescine levels and ADC activity was weak in this cultivar and was observed when necrotic lesions developed. Leaf injury occurred in both lines when the molar ratio of putrescine to 1-aminocyclopropane-1-carboxylic acid or ethylene fell short of a certain threshold value. Monocaffeoyl-putrescine, an effective scavenger for oxyradicals, was detected in the apo-plastic fluid of the leaves of cv Bel B and increased upon exposure to ozone. This extracellular localization could allow scavenging of ozone-derived oxyradicals at the first site of their generation. Induction of either polyamine or ethylene pathways may represent a control mechanism for inhibition or promotion of lesion formation and thereby contribute to the disposition of plants for ozone tolerance. PMID:16668067

  12. Addressing Global Change Issues Using Atmospheric Chemistry Observations from Space: Providing Measurements for the Recovery of the Ozone Layer, Climate, and Pollution

    NASA Astrophysics Data System (ADS)

    Fishman, J.

    2008-05-01

    As we enter the second decade of the 21st century, there is a trilogy of major issues around which satellite observations of trace gases and aerosols can be classified. The first large-scale problem focuses on the recovery of the stratospheric ozone layer, where satellites have a multi-decadal heritage of making important contributions to understanding the chemistry and dynamics of stratospheric ozone. The second aspect of this trilogy is the long-term build up of tropospheric trace gases and aerosols that affect climate, where relevant measurements include methane and the precursors to tropospheric ozone formation, nitrogen dioxide and carbon monoxide. Satellite observations during the past decade have provided new insight into both trends and interannual variability of key tropospheric trace gases. However, the last and the most challenging aspect of this trilogy deals with the capability to use space observations to observe and hopefully help mitigate the detrimental aspects of air pollution that result in widespread harm to human health and other biological systems. The recently released "Decadal Survey" by the U.S. National Research Council (NRC) concurs with this philosophy and strongly encourages the use of satellite measurements for societal benefits. The NRC emphasized that if Earth scientists are to foster applications and extend the societal benefits of their work, they must also understand that satellite measurements need to be transformed into useful information that is understandable and meets the needs of being a tool for those who make decisions regarding air quality and policy-makers as well as for scientists, the traditional users of such measurements. Specifically, with respect to future atmospheric chemistry missions, the NRC (2007) recommended that a mission dedicated to the measurement of tropospheric trace gases from a geostationary satellite should be launched in the 2013-2016 timeframe (GEO-CAPE, Geostationary Coastal and Air Pollution

  13. A simulation of stratospheric ozone in response to the increased surface CFCs emissions

    NASA Astrophysics Data System (ADS)

    Shi, Chunhua

    2009-08-01

    To evaluate the stratospheric process in the response to the increased surface CFCs emissions, some simulations were carried out by the NCAR interactive chemical, dynamical and radioactive two-dimensional (SOCRATES) model. The investigation showed that when the surface CFCs emissions increased by 30%, these chemical components would be transported into the stratosphere and would play an important roles in stratospheric chemistry and radiation. In the layers from 40km to 48km, the relative variety of active component was ClOx by 20%, HOx by -2%, NOx by -2% and O3 by -5%, respectively. At the same time, temperature reduced by 0.6K.

  14. [Effect of the increasing levels of soil radioactive pollution on the biochemical composition of plants].

    PubMed

    Gromova, V S; Pchelenok, O A; Kozlova, N M

    2012-01-01

    The study was undertaken to study a relationship between the changes of some parameters of the biochemical and mineral composition of different plants, such as rape, pods, and lentil, and the levels of soil radiation pollution, by using the conventional methods. Radioactive pollution of dark-grey forest soils was found to cause a change in the biochemical composition of plant seeds even at the level of cesium 137 (137Cs) within the present temporary permissible levels (TPL) (600 Bq/kg): there were elevated concentrations of salts of potassium, phosphorus, ammonia nitrogen, catechols, sucrose, and some amino acids. With the radioactive cesium level exceeding the TPL, biochemical changes in the seeds depended on the species of the plants: in the rape seeds, the additional formation of sucrose and amino acids continued, but less intensively than with its lower radiation; the pod beans were significantly positively correlated with the increasing amounts of catechols.

  15. [Effect of the increasing levels of soil radioactive pollution on the biochemical composition of plants].

    PubMed

    Gromova, V S; Pchelenok, O A; Kozlova, N M

    2012-01-01

    The study was undertaken to study a relationship between the changes of some parameters of the biochemical and mineral composition of different plants, such as rape, pods, and lentil, and the levels of soil radiation pollution, by using the conventional methods. Radioactive pollution of dark-grey forest soils was found to cause a change in the biochemical composition of plant seeds even at the level of cesium 137 (137Cs) within the present temporary permissible levels (TPL) (600 Bq/kg): there were elevated concentrations of salts of potassium, phosphorus, ammonia nitrogen, catechols, sucrose, and some amino acids. With the radioactive cesium level exceeding the TPL, biochemical changes in the seeds depended on the species of the plants: in the rape seeds, the additional formation of sucrose and amino acids continued, but less intensively than with its lower radiation; the pod beans were significantly positively correlated with the increasing amounts of catechols. PMID:22834257

  16. Influence of volatile terpenes on the capacity of leaves to uptake and detoxify ozone. (Invited)

    NASA Astrophysics Data System (ADS)

    Loreto, F.; Fares, S.

    2009-12-01

    Tropospheric ozone is considered the most dangerous air pollutant for plant ecosystems, and its concentration is increasing throughout the earth. Oxidative damage takes place when ozone penetrates inside the leaves through the stomata and the cuticles. The latest guidelines suggest considering the dose entering stomata to evaluate ozone risk on vegetation. We have shown that this metric may not consider important detoxification mechanisms activated by the production of volatile antioxidants, especially terpenes. We review here how volatile terpenes may increase ozone uptake by leaves yet reducing the risk of damage to internal leaf structures. We also argue that volatile terpene production by plants phases-in with episodes on high ozone whereas other detoxification mechanisms are phased-out. Our results suggests that volatile isoprenoids play a major role in determining the capacity of ozone removal and detoxification by vegetation.

  17. Introduction to the SONEX (Subsonic Assessment Ozone and Nitrogen Oxides Experiment) and POLINAT-2 (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) Special Issue

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Singh, Hanwant B.; Schlager, Hans; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Emissions of atmospheric species from the engines of subsonic aircraft at cruise altitude (roughly, above seven kilometers) are of concern to scientists, the aviation industry and policymakers for two reasons. First, water vapor, soot and sulfur oxides, and related heterogeneous processes, may modify clouds and aerosols enough to perturb radiative forcing in the UT/LS (upper troposphere/lower stratosphere). A discussion of these phenomena appears in Chapter 3 of the IPCC Aviation Assessment (1999). An airborne campaign conducted to evaluate aviation effects on contrail, cirrus and cloud formation, is described in Geophysical Research Letters. The second concern arises from subsonic aircraft emissions of nitrogen oxides (NO + NO2 = NO(sub x)), CO, and hydrocarbons. These species may add to the background mixture of photochemically reactive species that form ozone. In the UT/LS, ozone is a highly effective greenhouse gas. The impacts of subsonic aircraft emissions on tropospheric NO(sub x) and ozone budgets have been studied with models that focus on UT chemistry [e.g. see discussions of individual models in Brasseur et al., 1998; Friedl et al., 1997; IPCC, 1999]. Depending on the model used, projected increases in the global subsonic aircraft fleet from 1992 to 2015 will lead to a 50-100 pptv increase in UT/LS NO. at 12 km (compared to 50-150 pptv background) in northern hemisphere midlatitudes. The corresponding 12-km ozone increase is 7-11 ppbv, or 5-10% (Chapter 4 in IPCC, 1999). Two major sources of uncertainties in model estimates of aviation effects are: (1) the often limited degree to which global models - the scale required to evaluate aircraft emissions - realistically simulate atmospheric transport and other physical processes; (2) limited UT/LS observations of trace gases with which to evaluate model performance. In response to the latter deficiency, a number of airborne campaigns aimed at elucidating the effect of aircraft on atmospheric nitrogen oxides

  18. Outdoor air pollution and asthma

    PubMed Central

    Guarnieri, Michael; Balmes, John R.

    2015-01-01

    Traffic and power generation are the main sources of urban air pollution. The idea that outdoor air pollution can cause exacerbations of pre-existing asthma is supported by an evidence base that has been accumulating for several decades, with several studies suggesting a contribution to new-onset asthma as well. In this Series paper, we discuss the effects of particulate matter (PM), gaseous pollutants (ozone, nitrogen dioxide, and sulphur dioxide), and mixed traffic-related air pollution. We focus on clinical studies, both epidemiological and experimental, published in the previous 5 years. From a mechanistic perspective, air pollutants probably cause oxidative injury to the airways, leading to inflammation, remodelling, and increased risk of sensitisation. Although several pollutants have been linked to new-onset asthma, the strength of the evidence is variable. We also discuss clinical implications, policy issues, and research gaps relevant to air pollution and asthma. PMID:24792855

  19. Increasing fine particulate air pollution in China and the potential use of exposure and biomarker data in disease prevention.

    PubMed

    Wendt, Chris H; Ramachandran, Gurumurthy; Lo, Charles; Hertz, Marshall; Mandel, Jeffrey H

    2015-03-16

    Increased industrialization and urbanization have led to marked increases in air pollutants in China over the last decade. Pollutant levels in the north and eastern regions are often four times higher than current daily levels in the United States. Recent reports indicate a higher incidence of lung cancer and mortality in men and urban dwellers, but the contribution of air pollution to these findings remains unknown. Future studies that define individual exposures, combined with biomarkers linked to disease, will be essential to the understanding of risk posed by air pollution in China.

  20. Stratospheric Ozone and Temperature Changes in the Past: The Impact of Increased Concentrations of CFCs in Simulations with a Chemistry-Climate Model

    NASA Astrophysics Data System (ADS)

    Meul, S.; Oberländer, S.; Abalichin, J.; Kubin, A.; Langematz, U.

    2012-04-01

    Changes in stratospheric ozone between 1960 and the end of the 20th century are investigated analysing simulations with the Chemistry-Climate-Model (CCM) EMAC in FUB configuration (i.e. 39 layers with FUBRad parameterisation). In order to analyse the impact of increasing emissions of chlorofluorocarbons (CFCs) from 1960 to 2000 two sensitivity studies have been performed: a reference simulation with boundary conditions for the year 2000 and one analogue simulation but with CFC emissions reduced to 1960 levels. By comparing to a transient simulation (1960 to 2100) using the CCMVal SCN-B2d scenario it is possible to isolate the ozone changes that are caused by the CFC-increase only and separate the CFC-effect from other processes affecting ozone, e.g. climate change. By applying the method of Garny et al. (2011) the relative ozone changes arising from the CFC-modification can be attributed to changes in transport, chemical production and loss. Furthermore, it is analysed how the processes related to the CFC-increase contribute to the stratospheric cooling of up to 4K that is simulated by the SCN-B2d run between the 1960s and the 2000s in the upper stratosphere. The temperature change due to increased CFCs is caused by a reduced absorption of solar radiation by decreased ozone concentrations combined with the greenhouse gas (GHG) effect of the CFCs. In the upper stratosphere a cooling of up to 2.5K can be explained by the CFC-increase.

  1. Ozone temporal variations at Whiteface Mountain and processes responsible for these variations

    NASA Astrophysics Data System (ADS)

    Su, Xiujuan

    1998-12-01

    A 22-year-record of hourly ozone concentrations measured at Whiteface Mountain (WFM), New York, is analyzed and possible processes impacting ozone temporal variations as seasonal, interannual, and long term trends are discussed. As a rural mountain site, ozone is not produced locally but is transported from upwind areas. The seasonal variation accounts for 91% of the total variance, with broad peak from April and August. The peak time of ozone seasonal cycle for the air masses from clean areas occurs between March and May while the peak time of ozone seasonal cycle for the air masses from polluted areas occurs between May and August. Ozone concentrations for air masses from polluted areas in summer and fall are higher than those for air masses from clean area. The findings of this study and other suggest that upwind photochemical production and stratospheric intrusion are major processes for shaping this type of seasonal cycle at Whiteface Mountain. There are considerable interannual variations of ozone at Whiteface Mountain, characterized as two peaks and one minimum. Six dominant cycles, 132, 88, 66, 53, 44, and 29 months are identified in the interannual variations of ozone. The possible links between ozone and ENSO and solar cycle are weak and cannot be proven in this study. The long term trends of ozone at Whiteface Mountain change temporally, depending on time periods and season. The greatest increase rate occurs in 1970s and there is a decrease rate in 1990s (but not statistically significant). The facts that there is a similarity between ozone and NOx emission trends and synoptic systems have little influence on ozone changes may suggest that NOx emission is a major process for ozone changes over years. Most high ozone episodes with 1-hour ozone concentration exceeding 120 ppb or 80 ppb occur before 1980s when synoptic system are favorable to photochemical production. In additions, the air masses for these high ozone episodes are mostly advected from

  2. Ozone concentrations and damage for realistic future European climate and air quality scenarios

    NASA Astrophysics Data System (ADS)

    Hendriks, Carlijn; Forsell, Nicklas; Kiesewetter, Gregor; Schaap, Martijn; Schöpp, Wolfgang

    2016-11-01

    Ground level ozone poses a significant threat to human health from air pollution in the European Union. While anthropogenic emissions of precursor substances (NOx, NMVOC, CH4) are regulated by EU air quality legislation and will decrease further in the future, the emissions of biogenic NMVOC (mainly isoprene) may increase significantly in the coming decades if short-rotation coppice plantations are expanded strongly to meet the increased biofuel demand resulting from the EU decarbonisation targets. This study investigates the competing effects of anticipated trends in land use change, anthropogenic ozone precursor emissions and climate change on European ground level ozone concentrations and related health and environmental impacts until 2050. The work is based on a consistent set of energy consumption scenarios that underlie current EU climate and air quality policy proposals: a current legislation case, and an ambitious decarbonisation case. The Greenhouse Gas-Air Pollution Interactions and Synergies (GAINS) integrated assessment model was used to calculate air pollutant emissions for these scenarios, while land use change because of bioenergy demand was calculated by the Global Biosphere Model (GLOBIOM). These datasets were fed into the chemistry transport model LOTOS-EUROS to calculate the impact on ground level ozone concentrations. Health damage because of high ground level ozone concentrations is projected to decline significantly towards 2030 and 2050 under current climate conditions for both energy scenarios. Damage to plants is also expected to decrease but to a smaller extent. The projected change in anthropogenic ozone precursor emissions is found to have a larger impact on ozone damage than land use change. The increasing effect of a warming climate (+2-5 °C across Europe in summer) on ozone concentrations and associated health damage, however, might be higher than the reduction achieved by cutting back European ozone precursor emissions. Global

  3. Short-term effects of multiple ozone metrics on daily mortality in a megacity of China.

    PubMed

    Li, Tiantian; Yan, Meilin; Ma, Wenjun; Ban, Jie; Liu, Tao; Lin, Hualiang; Liu, Zhaorong

    2015-06-01

    Epidemiological studies have widely demonstrated association between ambient ozone and mortality, though controversy remains, and most of them only use a certain metric to assess ozone levels. However, in China, few studies have investigated the acute effects of ambient ozone, and rare studies have compared health effects of multiple daily metrics of ozone. The present analysis aimed to explore variability of estimated health effects by using multiple temporal ozone metrics. Six metrics of ozone, 1-h maximum, maximum 8-h average, 24-h average, daytime average, nighttime average, and commute average, were used in a time-series study to investigate acute mortality associated with ambient ozone pollution in Guangzhou, China, using 3 years of daily data (2006-2008). We used generalized linear models with Poisson regression incorporating natural spline functions to analyze the mortality, ozone, and covariate data. We also examined the association by season. Daily 1- and 8-h maximum, 24-h average, and daytime average concentrations yielded statistically significant associations with mortality. An interquartile range (IQR) of O3 metric increase of each ozone metric (lag 2) corresponds to 2.92 % (95 % confidence interval (CI) 0.24 to 5.66), 3.60 % (95 % CI, 0.92 to 8.49), 3.03 % (95 % CI, 0.57 to 15.8), and 3.31 % (95 % CI, 0.69 to 10.4) increase in daily non-accidental mortality, respectively. Nighttime and commute metrics were weakly associated with increased mortality rate. The associations between ozone and mortality appeared to be more evident during cool season than in the warm season. Results were robust to adjustment for co-pollutants, weather, and time trend. In conclusion, these results indicated that ozone, as a widespread pollutant, adversely affects mortality in Guangzhou.

  4. Increased vitamin E content in the lung after ozone exposure: A possible mobilization in response to oxidative stress

    SciTech Connect

    Elsayed, N.M.; Mustafa, M.G.; Mead, J.F. )

    1990-11-01

    Vitamin E (vE) is a biological free radical scavenger capable of providing antioxidant protection depending upon its tissue content. In previous studies, we observed that vE increased significantly in rat lungs after oxidant exposure, and we postulated that vE may be mobilized to the lung from other body sites under oxidative stress. To test this hypothesis, we fed Long-Evans rats either a vE-supplemented or a vE-deficient diet, injected them intraperitoneally with 14C-labeled vE, and then exposed half of each group to 0.5 ppm ozone (O3) for 5 days. After exposure, we determined vE content and label retention in lungs, liver, kidney, heart, brain, plasma, and white adipose tissue. Tissue vE content of all tissues generally reflected the dietary level, but labeled vE retention in all tissues was inversely related to tissue content, possibly reflecting a saturation of existing vE receptor sites in supplemented rats. Following O3 exposure, lung vE content increased significantly in supplemented rats and decreased in deficient rats, but the decrease was not statistically significant, and vE content remained unchanged in all other tissues of both dietary groups. Retention of 14C-labeled vE increased in all tissues of O3-exposed rats of both dietary groups, except in vE-deficient adipose tissue and vE-supplemented brain, where it decreased, and plasma, where it did not change. The marked increases in lung vE content and labeled vE retention of O3-exposed vE-supplemented rats support our hypothesis that vE may be mobilized to the lung in response to oxidative stress, providing that the vitamin is sufficiently available in other body sites.

  5. Relationship between acceleration of hydroxyl radical initiation and increase of multiple-ultrasonic field amount in the process of ultrasound catalytic ozonation for degradation of nitrobenzene in aqueous solution.

    PubMed

    Zhao, Lei; Ma, Weichao; Ma, Jun; Wen, Gang; Liu, Qianliang

    2015-01-01

    The synergetic effect between ozone and ultrasound can enhance the degradation of nitrobenzene and removal efficiency of TOC in aqueous solution, and the degradation of nitrobenzene follows the mechanism of hydroxyl radical (OH) oxidation. Under the same total ultrasonic power input condition, the degradation rate of nitrobenzene (kNB), the volumetric mass transfer coefficient of ozone (kLa), and the initiation rate of OH (kOH) increases with introduction of additional ultrasonic field (1-4) in the process of ozone/ultrasound. The increasing amount of ultrasonic fields accelerates the decomposition of ozone, leading to the rapid appearance of the maximum equilibrium value and the decrease in the accumulation concentration of ozone in aqueous solution with the increasing reaction time. The increase in mass transfer of gaseous ozone dissolved into aqueous solution and the acceleration in the decomposition of ozone in aqueous solution synchronously contribute to the increase of kLa. The investigation of mechanism confirms that the increasing amount of ultrasonic fields yields the increase in cavitation activity that improves the mass transfer and decomposition of ozone, resulting in acceleration of OH initiation, which determines the degradation of nitrobenzene in aqueous solution.

  6. The study of ozone variations in the Las Vegas metropolitan area using remote sensing information and ground observations

    USGS Publications Warehouse

    Xian, G.; Crane, M.

    2006-01-01

    Urban development in the Las Vegas Valley, Nevada, has grown rapidly in the past fifty years. Associated with this growth has been a change in landscape from natural cover types to developed urban land mixed with planned vegetation canopy throughout in the metropolitan area. Air quality in the Las Vegas Valley has been affected by increases in anthropogenic emissions and concentrations of carbon monoxide, ozone, and criteria pollutants of particular matter. Ozone concentration in the region is generally influenced by synoptic and mesoscale meteorological conditions, as well as regional transport of pollutants from the western side of Las Vegas. Local influences from ground-level nitrogen oxide emissions and vegetation canopy coverage also affect ozone concentration. Multi-year observational data collected by a network of local air monitoring stations in Clark County, Nevada, indicate that ozone maximums develop in May and June, while minimums exist primarily from November to February. Ozone concentrations are high on the west and northwest sides of the valley. A nighttime ozone reduction in the urban area characterizes the heterogeneous features of spatial distribution for average ozone levels in the Las Vegas urban area. The urban vegetation canopy has a locally positive effect by reducing ozone in urban areas. Decreased ozone levels associated with increased urban development density suggests that the highest ozone concentrations are associated with medium- to low-density urban development in Las Vegas.

  7. Observational studies and a statistical early warning of surface ozone pollution in Tangshan, the largest heavy industry city of North China.

    PubMed

    Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

    2013-03-01

    Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37'N, 118°09'E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 μg/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008-2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 μg/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 μg/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 μg/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 μg/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 μg/m3 and 33 °C, respectively. PMID:23485953

  8. The effect of the Standard Nomenclature for Air Pollution (SNAP) categories on ozone and PM2.5 concentrations over Europe

    NASA Astrophysics Data System (ADS)

    Tagaris, Efthimios; Sotiropoulou, Rafaella-Eleni P.; Gounaris, Nikos; Andronopoulos, Spyros; Vlachogiannis, Diamando

    2015-04-01

    The objective of this study is to estimate the contribution of different anthropogenic emission sources on ozone and PM2.5 concentrations over Europe since anthropogenic activities (and the related emissions) are the reason of air quality degradation. Gridded yearly averaged anthropogenic emissions for the year 2006 over Europe are provided by TNO at a 0.1×0.1 degree resolution. Emission sources have been classified into different activities according to the Standard Nomenclature for Air Pollution (SNAP). The available data include annual total emissions of CH4, CO, NH3, NMVOC, NOx, PM10, PM2.5, and SO2 for both area and point sources in ten (10) SNAP categories: power generation, residential-commercial and other combustion, industrial combustion, industrial processes, extraction distribution of fossil fuels, solvent use, road transport, other mobile sources, waste treatment and disposal, agriculture. Mobile sources and road transport are the major sources of NOx emissions followed by power generation units. Power generation is also the major source for SO2 emissions followed by mobile sources. Agricultural activities dominate NH3 emissions while combustion sources followed by mobile sources and road transport are the main sources for primary PM2.5. Emissions are processed by the Sparse Matrix Operator Kernel Emissions (SMOKE) v2.6 modeling system to convert their resolution to the resolution needed by the air quality model The Community Multiscale Air Quality (CMAQ) v4.7 Modeling System with the Carbon Bond mechanism (CB05) is used for the regional air quality modeling over Europe at 35km grid spacing. Results quantify the contribution of each SNAP category on ozone and PM2.5 concentrations, locally, across Europe.

  9. Observational Studies and a Statistical Early Warning of Surface Ozone Pollution in Tangshan, the Largest Heavy Industry City of North China

    PubMed Central

    Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

    2013-01-01

    Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37′N, 118°09′E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 μg/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008–2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 μg/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 μg/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 μg/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 μg/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 μg/m3 and 33 °C, respectively. PMID:23485953

  10. Use of ozonation to mitigate fouling in a long-term membrane bioreactor.

    PubMed

    Wu, Jinling; Huang, Xia

    2010-08-01

    In order to confirm the effect of ozonation on fouling mitigation in long-term membrane bioreactors (MBRs), parallel operation of two MBRs with and without ozonation was repeated in triplicate with different dosing modes. A number of mixed liquor properties and removal of pollutants in both MBRs were investigated. Membrane fouling was effectively retarded by ozonation in long-term MBRs. The best dosage was 0.25 mg g(-1)-SS at 1 day intervals. A slow formation of a gel layer on membrane surface was the result of the low organics in the supernatant and the low extractable extra-cellular polymeric substances in the MBR-ozone system. Ozonation also enlarged suspended flocs by reducing zeta-potential and increasing hydrophobicity, thus enhancing flocculability of the particles in the mixed liquor. The microbial activity was somewhat inhibited, however, the effluent quality of the system was not affected. These findings indicate the feasibility of using ozone to improve MBR efficiency.

  11. Methodological issues in studies of air pollution and reproductive health

    EPA Science Inventory

    In the past decade there have been an increasing number of scientific studies describing possible effects of air pollution on perinatal health. These papers have mostly focused on commonly monitored air pollutants, primarily ozone (O3), particulate matter (PM), sulfur dioxide (S...

  12. Natural zeolite reactivity towards ozone: the role of compensating cations.

    PubMed

    Valdés, Héctor; Alejandro, Serguei; Zaror, Claudio A

    2012-08-15

    Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L(-1)). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH(3)-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  13. Impact of Model Resolution and Snow Cover Modification on the Performance of Weather Forecasting and Research (WRF) Models of Winter Conditions that Contribute to Ozone Pollution in the Uintah Basin, Eastern Utah, Winter 2013. Trang T. Tran, Marc Mansfield and Seth Lyman Bingham Research Center, Utah State University

    NASA Astrophysics Data System (ADS)

    Tran, T. T.; Mansfield, M. L.; Lyman, S.

    2013-12-01

    The Uintah Basin of Eastern Utah, USA, has experienced winter ozone pollution events with ozone concentrations exceeding the National Ambient Air Quality Standard of 75 ppb. With a total of four winter seasons of ozone sampling, winter 2013 is the worst on record for ozone pollution in the basin. Emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from oil and gas industries and other activities provide the precursors for ozone formation. The chemical mechanism of ozone formation is non-linear and complicated depending on the availability of VOCs and NOx. Moreover, meteorological conditions also play an important role in triggering ozone pollution. In the Uintah Basin, high albedo due to snow cover, a 'bowl-shaped' terrain, and strong inversions that trap precursors within the boundary layer are important factors contributing to ozone pollution. However, these local meteorological phenomena have been misrepresented by recent numerical modeling studies, probably due to misrepresenting the snow cover and complex terrain of the basin. In this study, Weather Research and Forecasting (WRF) simulations are performed on a model domain covering the entire Uintah Basin for winter 2013 (Dec 2012 - Mar 2013) to test the impacts of several grid resolutions (e.g., 4000, 1300 and 800m) and snow cover modification on performance of models of the local weather conditions of the basin. These sensitivity tests help to determine the best model configurations to produce appropriate meteorological input for air-quality simulations.

  14. Exposure Information in Environmental Health Research: Current Opportunities and Future Directions for Particulate Matter, Ozone, and Toxic Air Pollutants

    EPA Science Inventory

    In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in ord...

  15. Assessment of Fenton's reagent and ozonation as pre-treatments for increasing the biodegradability of aqueous diethanolamine solutions from an oil refinery gas sweetening process.

    PubMed

    Durán-Moreno, A; García-González, S A; Gutiérrez-Lara, M R; Rigas, F; Ramírez-Zamora, R M

    2011-02-28

    The aim of this work was to evaluate the efficiency of three chemical oxidation processes for increasing the biodegradability of aqueous diethanolamine solutions (aqueous DEA solutions), to be used as pre-treatments before a biological process. The raw aqueous DEA solution, sourced from a sour gas sweetening plant at a Mexican oil refinery, was first characterized by standardized physico-chemical methods. Then experiments were conducted on diluted aqueous DEA solutions to test the effects of Fenton's reagent, ozone and ozone-hydrogen peroxide on the removal of some physicochemical parameters of these solutions. Lastly, biodegradability tests based on Dissolved Organic Carbon Die Away OECD301-A, were carried out on a dilution of the raw aqueous DEA solution and on the treated aqueous DEA solutions, produced by applying the best experimental conditions determined during the aforementioned oxidation tests. Experimental results showed that for aqueous DEA solutions treated with Fenton's reagent, the best degradation rate (70%) was obtained at pH 2.8, with Fe(2+) and H(2)O(2) at doses of 1000 and 10,000 mg/L respectively. In the ozone process, the best degradation (60%) was observed in aqueous DEA solution (100 mg COD/L), using 100 mg O(3)/L at pH 5. In the ozone-hydrogen peroxide process, no COD or DOC removals were observed. The diluted spent diethanolamine solution showed its greatest increase in biodegradability after a reaction period of 28 days when treated with Fenton's reagent, but after only 15 days in the case of ozonation.

  16. Ecological issues related to ozone: agricultural issues.

    PubMed

    Fuhrer, Jürg; Booker, Fitzgerald

    2003-06-01

    Research on the effects of ozone on agricultural crops and agro-ecosystems is needed for the development of regional emission reduction strategies, to underpin practical recommendations aiming to increase the sustainability of agricultural land management in a changing environment, and to secure food supply in regions with rapidly growing populations. Major limitations in current knowledge exist in several areas: (1) Modelling of ozone transfer and specifically stomatal ozone uptake under variable environmental conditions, using robust and well-validated dynamic models that can be linked to large-scale photochemical models lack coverage. (2) Processes involved in the initial reactions of ozone with extracellular and cellular components after entry through the stomata, and identification of key chemical species and their role in detoxification require additional study. (3) Scaling the effects from the level of individual cells to the whole-plant requires, for instance, a better understanding of the effects of ozone on carbon transport within the plant. (4) Implications of long-term ozone effects on community and whole-ecosystem level processes, with an emphasis on crop quality, element cycling and carbon sequestration, and biodiversity of pastures and rangelands require renewed efforts. The UNECE Convention on Long Range Trans-boundary Air Pollution shows, for example, that policy decisions may require the use of integrated assessment models. These models depend on quantitative exposure-response information to link quantitative effects at each level of organization to an effective ozone dose (i.e., the balance between the rate of ozone uptake by the foliage and the rate of ozone detoxification). In order to be effective in a policy, or technological context, results from future research must be funnelled into an appropriate knowledge transfer scheme. This requires data synthesis, up-scaling, and spatial aggregation. At the research level, interactions must be

  17. Pollution and Climate Change

    ERIC Educational Resources Information Center

    Larr, Allison S.; Neidell, Matthew

    2016-01-01

    Childhood is a particularly sensitive time when it comes to pollution exposure. Allison Larr and Matthew Neidell focus on two atmospheric pollutants--ozone and particulate matter--that can harm children's health in many ways. Ozone irritates the lungs, causing various respiratory symptoms; it can also damage the lung lining or aggravate lung…

  18. [Degradation of nitrobenzene in aqueous solution by modified ceramic honeycomb-catalyzed ozonation].

    PubMed

    Sun, Zhi-Zhong; Zhao, Lei; Ma, Jun

    2005-11-01

    Comparative experiments of modified ceramic honeycomb, ceramic honeycomb-catalyzed ozonation and ozonation alone were conducted with nitrobenzene as the model organic pollutant. It was found that the processes of modified ceramic honeycomb and ceramic honeycomb-catalyzed ozonation could increase the removal efficiency of nitrobenzene by 38.35% and 15.46%, respectively, compared with that achieved by ozonation alone. Under the conditions of this experiment, the degradation rate of modified ceramic honeycomb-catalyzed ozonation increased by 30.55% with the increase of amount of catalyst to 5 blocks. The degradation rate of three process all increased greatly with the increase of temperature and value of pH in the solution. But when raising the pH value of the solution to 10.00, the advantage of modified ceramic honeycomb-catalyzed ozonation processes lost. The experimental results indicate that in modified ceramic honeycomb-catalyzed ozonation, nitrobenzene is primarily oxidized by *OH free radical in aqueous solution. The adsorption of nitrobenzene is too limited to have any influence on the degradation efficiency of nitrobenzene. With the same total dosage of applied ozone, the multiple steps addition of ozone showed a much higher removal efficiency than that obtained by one step in three processes. Modified ceramic honeycomb had a relative longer lifetime.

  19. Spatial analysis of ozone in Atlanta: Regulatory and epidemiologic implications

    SciTech Connect

    Butler, A.J.; Mulholland, J.A.; Wilkinson, J.G.; Russell, A.G.; Tolbert, P.E.

    1998-12-31

    Relationships between ambient levels of selected air pollutants and pediatric asthma exacerbation in Atlanta were studied retrospectively. As a part of this study, spatial distributions of ambient ozone concentrations in the twenty-county Atlanta metropolitan area during the summers of 1993, 1994 and 1995 were estimated and assessed. A universal kriging procedure was used for spatial interpolation of aerometric monitoring station data. In this paper, the spatial distributions of ozone are described, and regulatory and epidemiologic implications are discussed. For the study period, the Atlanta ozone nonattainment area based on the one-hour, exceedance-based standard of 0.12 ppm is estimated to expand from 56 percent of the Atlanta MSA by area and 71 percent by population to 88 percent by area and 96 percent by population under the new eight-hour, concentration-based standard of 0.08 ppm. Regarding asthma exacerbation, a 4 percent increase in pediatric asthma emergency room presentation rate per 20 ppb increase in ambient ozone concentration was observed (p-value = 0.001). Ambient ozone level represents a general indicator of air quality due to its correlation with other pollutants. The use of spatially-resolved ozone estimates in the epidemiologic analysis demonstrates the need to control confounding by demographic covariates.

  20. Tackling pollution by organic farming is capable of increasing fortified foods.

    PubMed

    Navarro-Aviñó, J P; Navarro, J J Fernández; Castro, V Vargas; Ripoll, I Ilzarbe; Sahuquillo, M J Márquez

    2016-01-01

    The global pollution stage is poisoning the biosphere and causing global temperatures to rise, necessitating a drastic change in the way man is dealing with nature. One change that may produce many beneficial effects on the biosphere and human health is the use of specific organic farming to produce food in a more integrated way in nature and to increase the capacity of man's own response. Despite many experts' opinion another way to deal with environmental contamination is possible: organic farming, which can increase man's ability to fortify foods. After more than 20 years working under this discipline, Bodegas Dagon is able to achieve the highest stilbenes concentrations (as resveratrol). Versus 14.3 mg/l, "Bodegas Dagón" wines contain resveratrol (HPLC and UV-spectroscopy) up to 1611.73 ± 72.66 mg/l, standing as world's potentially healthiest wine reported to date.

  1. Plant responses to tropospheric ozone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone is the second most abundant air pollutant and an important component of the global climate change. Over five decades of research on the phytotoxicity of ozone in model plants systems, crop plants and forest trees have provided some insight into the physiological, biochemical and m...

  2. Pollution from China increases cloud droplet number, suppresses rain over the East China Sea

    SciTech Connect

    Bennartz, Ralph; Fan, Jiwen; Rausch, J; Leung, Lai-Yung R; Heidinger, Andrew K

    2011-05-18

    Rapid economic growth over the last 30 years in China has led to a significant increase in aerosol loading, which is mainly due to the increased emissions of its precursors such as SO2 and NOx. Here we show that these changes significantly affect wintertime clouds and precipitation over the East China Sea downwind of major emission sources. Satellite observations show an increase of cloud droplet number concentration from less than 200 cm-3 in the 1980s to more than 300 cm-3 in 2005. In the same time period, precipitation frequency reported by voluntary ship observers was reduced from more than 30% to less than 20% of the time. A back trajectory analysis showed the pollution in the investigation area to originate from the Shanghai-Nanjing and Jinan industrial areas. A model sensitivity study was performed, isolating the effects of changes in emissions of the aerosol precursors SO2 and NOx on clouds and precipitation using a state-of-the-art mesocale model including chemistry and aerosol indirect effects. Similar changes in cloud droplet number concentration over the East China Sea were obtained when the current industrial emissions in China were reduced to the 1980s levels. Simulated changes in precipitation were somewhat smaller than the observed changes but still significant. Citation: Bennartz, R., J. Fan, J. Rausch, L. R. Leung, and A. K. Heidinger (2011), Pollution from China increases cloud droplet number, suppresses rain over the East China Sea, Geophys. Res. Lett., 38, L09704, doi:10.1029/ 2011GL047235.

  3. 78 FR 4333 - National Oil and Hazardous Substances Pollution Contingency Plan; Revision To Increase Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ..., Water pollution control, Water supply. Dated: January 15, 2013. Mathy Stanislaus, Assistant... AGENCY 40 CFR Part 300 RIN 2050-AG73 National Oil and Hazardous Substances Pollution Contingency Plan... are withdrawing the direct final rule for National Oil and Hazardous Substances Pollution...

  4. Aeration remediation of a polluted waterway increases near-surface coarse and culturable microbial aerosols.

    PubMed

    Dueker, M Elias; O'Mullan, Gregory D

    2014-04-15

    Aeration remediation is currently used in polluted urban waterways to increase oxygen levels in the water column. Recent studies have provided increasing evidence that the bursting of bubbles at water surfaces introduced by aeration, or other surface disturbances, can transfer viable bacteria to the air. In heavily sewage-polluted waterways these water-originated bacterial aerosols may pose as a health risk to recreators in small boats or residents inhabiting the shoreline. Nonetheless, few studies have explored aerosols above active aeration remediation projects in waterways or investigated how bacterial aerosols change with vertical distance from aeration activities. This study, conducted at the Newtown Creek superfund site in Brooklyn, NY, USA, measured coarse aerosol particles and culturable bacteria in near-surface air above waters undergoing aeration remediation. Regardless of aeration operation culturable bacterial fallout was greater near-surface (0.6m above water) than previously-reported measurements made at 2.5m. Molecular analysis of the 16S rRNA gene sequences from isolated bacteria demonstrates that water and air shared a large number of bacterial genera and that the genera present in the near-surface aerosols (0.6m) contained water-associated Vibrio and Caulobacter, which were not present at 2.5m, despite the smaller sequence library size from the near-surface. Also, the near-surface microbial assemblage had significantly greater association with sequences detected previously in aquatic environments compared to the 2.5m library. We found compelling evidence that aeration activity contributed to this vertical gradient in bacterial aerosol concentrations and identity. Similar to results from 2.5m, concentrations of near-surface respirable coarse aerosols (<10 um) increased significantly when aeration was occurring. Culturable bacterial aerosol fallout was also greater near-surface when the aerator was on compared to simultaneous measurements made at 2

  5. Causes of increasing ozone and decreasing carbon monoxide in springtime at the Mt. Bachelor Observatory from 2004 to 2013

    NASA Astrophysics Data System (ADS)

    Gratz, L. E.; Jaffe, D. A.; Hee, J. R.

    2015-05-01

    We report trends in springtime ozone (O3) and carbon monoxide (CO) at the Mt. Bachelor Observatory (MBO) in central Oregon, U.S.A. from 2004 to 2013. Over the 10-year period the median and 95th percentile springtime O3 increased by 0.76 ± 0.61 ppbv yr-1 (1.7 ± 1.4% yr-1) and 0.87 ± 0.73 ppbv yr-1 (1.5 ± 1.2% yr-1), respectively. These trends are consistent with reported positive trends in springtime O3 in the western U.S. In contrast, median CO decreased by -3.1 ± 2.4 ppbv yr-1 (-1.9 ± 1.4% yr-1), which is highly similar to springtime North Pacific surface flask measurements from 2004 to 2012. While a 10-year record is relatively short to evaluate long-term variability, we incorporate transport model analysis and contextualize our measurements with reported northern mid-latitude trends over similar time frames to investigate the causes of increasing O3 and decreasing CO at MBO. We performed cluster analysis of 10-day HYSPLIT back-trajectories from MBO and examined O3 and CO trends within each cluster. Significant positive O3 trends were associated with high-altitude, rapid transport from East Asia. Significant negative CO trends were most associated with transport from the North Pacific and Siberia, as well as from East Asia. The rise in springtime O3 is likely associated with increasing O3 precursor emissions in Asia and long-range transport to the western U.S. The decline in springtime CO appears linked to decreasing Northern Hemisphere background CO, largely due to anthropogenic emissions reductions in Europe and North America, and also to a recently reported decline in total CO output from China caused by more efficient combustion. These springtime O3 and CO trends suggest that hydroxyl radical (OH) mixing ratios in the North Pacific may have increased over the study period.

  6. Tropospheric ozone over the North Pacific from ozonesonde observations

    NASA Astrophysics Data System (ADS)

    Oltmans, S. J.; Johnson, B. J.; Harris, J. M.; Thompson, A. M.; Liu, H. Y.; Chan, C. Y.; VöMel, H.; Fujimoto, T.; Brackett, V. G.; Chang, W. L.; Chen, J.-P.; Kim, J. H.; Chan, L. Y.; Chang, H.-W.

    2004-08-01

    As part of the Transport and Chemical Evolution over the Pacific (TRACE-P) mission, ozonesondes were used to make ozone vertical profile measurements at nine locations in the North Pacific. At most of the sites there is a multiyear record of observations. From locations in the western Pacific (Hong Kong; Taipei; Jeju Island, Korea; and Naha, Kagoshima, Tsukuba, and Sapporo, Japan), a site in the central Pacific (Hilo, Hawaii), and a site on the west coast of the United States (Trinidad Head, California) both a seasonal and event specific picture of tropospheric ozone over the North Pacific emerges. Ozone profiles over the North Pacific generally show a prominent spring maximum throughout the troposphere. This maximum is tied to the location of the jet stream and its influence on stratosphere-troposphere exchange and the increase in photochemical ozone production through the spring. Prominent layers of enhanced ozone in the middle and upper troposphere north of about 30°N seem to be more closely tied to stratospheric intrusions while biomass burning leads to layers of enhanced ozone in the lower and upper troposphere at Hong Kong (22°N) and Taipei (25°N). The lower free tropospheric layers at Hong Kong are associated with burning in SE Asia, but the upper layer may be associated with either equatorial Northern Hemisphere burning in Africa or SE Asian biomass burning. In the boundary layer at Taipei very high mixing ratios of ozone were observed that result from pollution transport from China in the spring and local urban pollution during the summer. At the ozonesonde site near Tokyo (Tsukuba, 36°N) very large enhancements of ozone are seen in the boundary layer in the summer that are characteristic of urban air pollution. At sites in the mid and eastern Pacific the signature of transport of polluted air from Asia is not readily identifiable from the ozonesonde profile. This is likely due to the more subtle signal and the fact that from the ozone profile and

  7. Increased estimates of air-pollution emissions from Brazilian sugar-cane ethanol

    NASA Astrophysics Data System (ADS)

    Tsao, C.-C.; Campbell, J. E.; Mena-Carrasco, M.; Spak, S. N.; Carmichael, G. R.; Chen, Y.

    2012-01-01

    Accelerating biofuel production has been promoted as an opportunity to enhance energy security, offset greenhouse-gas emissions and support rural economies. However, large uncertainties remain in the impacts of biofuels on air quality and climate. Sugar-cane ethanol is one of the most widely used biofuels, and Brazil is its largest producer. Here we use a life-cycle approach to produce spatially and temporally explicit estimates of air-pollutant emissions over the whole life cycle of sugar-cane ethanol in Brazil. We show that even in regions where pre-harvest field burning has been eliminated on half the croplands, regional emissions of air pollutants continue to increase owing to the expansion of sugar-cane growing areas, and burning continues to be the dominant life-cycle stage for emissions. Comparison of our estimates of burning-phase emissions with satellite estimates of burning in São Paulo state suggests that sugar-cane field burning is not fully accounted for in satellite-based inventories, owing to the small spatial scale of individual fires. Accounting for this effect leads to revised regional estimates of burned area that are four times greater than some previous estimates. Our revised emissions maps thus suggest that biofuels may have larger impacts on regional climate forcing and human health than previously thought.

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

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.

    2007-01-01

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

  9. Estimating the Tropospheric Ozone Distribution by the Assimilation of Satellite Data

    NASA Technical Reports Server (NTRS)

    Hayashi, Hiroo; Stajner, Ivanka; Winslow, Nathan; Jones, Dylan B. A.; Pawson, Steven; Thompson, Anne M.

    2003-01-01

    Tropospheric ozone is important to the environment, because it acts as a strong oxidant to control the concentrations of many reduced gases (methane, carbon monoxide, ... ), its radiative forcing plays a significant role in the greenhouse effect, and direct contact with ozone is harmful to human health. Tropospheric ozone, whose main sources are intrusion from the stratosphere and chemical production from source gases associated with urban pollution or biomass burning, varies on a wide range of spatial and temporal scales. Its transport and chemistry can be influenced by weather, seasonal, or multiannual variability. Despite the importance of tropospheric ozone, it contributes only about 10% of the total ozone loading in the atmosphere. Consequently, satellite instruments lose sensitivity below the stratospheric ozone peak, and provide little information about middle and lower tropospheric ozone. This talk will discuss recent modifications made to the satellite ozone data assimilation system at NASA's Data Assimilation Office (DAO) in order to provide better tropospheric ozone columns and profiles. We use a version of the system that assimilates only the data from the Solar Backscatter UltraViolet/2 (SBUV/2) instrument. The quality of the assimilated ozone in the tropical troposphere is evaluated by comparison with independent observations obtained from the Southern Hemispheric Additional Ozonesondes (SHADOZ) network. It is shown that the quality of ozone fields is sensitive to the winds used in the transport model. Increasing the vertical resolution of the model also has a beneficial impact. The assimilated ozone in the lower troposphere was substantially improved by inclusion of tropospheric ozone production, loss, and dry deposition rates from the Harvard GEOS-CHEM model. The mechanisms behind these results will be examined and the implications for our understanding of tropospheric ozone will be discussed.

  10. Aconitine Challenge Test Reveals a Single Exposure to Air Pollution Causes Increased Cardiac Arrhythmia Risk in Hypertensive Rats - Abstract

    EPA Science Inventory

    Epidemiological studies demonstrate a significant association between arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electrical dysfunction. In this study, ...

  11. Midweek Increase in U.S. Summer Rain and Storm Heights, Suggests Air Pollution Invigorates Rainstorms

    NASA Technical Reports Server (NTRS)

    Bell, Thomas L.; Rosenfeld, Daniel; Kim, Kyu-Myong; Yoo, Jung-Moon; Hahnenberger, Maura

    2007-01-01

    Tropical Rainfall Measuring Mission (TRMM) satellite data show a significant midweek increase in summertime rainfall over the southeast U.S., due to afternoon intensification. TRMM radar data show a significant midweek increase in rain area and in the heights reached by afternoon storms. Weekly variations in model-reanalysis wind patterns over the region and in rain-gauge data are consistent with the satellite data. A midweek decrease of rainfall over the nearby Atlantic is also seen. EPA measurements of particulate concentrations show a midweek peak over much of the U.S. These observations are consistent with the theory that anthropogenic air pollution suppresses cloud-drop coalescence and early rainout during the growth of thunderstorms over land, allowing more water to be carried above the 0 C isotherm, where freezing yields additional latent heat, invigorating the storms--most dramatically evidenced by the shift in the midweek distribution of afternoon-storm heights--and producing large ice hydrometeors. The enhanced convection induces regional convergence, uplifting and an overall increase of rainfall. Compensating downward air motion suppresses convection over the adjacent ocean areas. Pre-TRMM-era data suggest that the weekly cycle only became strong enough to be detectable beginning in the 1980's. Rain-gauge data also suggest that a weekly cycle may have been detectable in the 1940's, but with peak rainfall on Sunday or Monday, possibly explained by the difference in composition of aerosol pollution at that time. This "weekend effect" may thus offer climate researchers an opportunity to study the regional climate-scale impact of aerosols on storm development and monsoon-like circulation.

  12. Water disinfection with ozone, copper and silver ions, and temperature increase to control Legionella: seven years of experience in a university teaching hospital.

    PubMed

    Blanc, D S; Carrara, Ph; Zanetti, G; Francioli, P

    2005-05-01

    The efficacy of ozonation, copper-silver ionization and increased temperature in controlling Legionella spp. in the hot water distribution networks of a university hospital was evaluated. Two separate water distribution networks were studied; network 1 which supplies the surgical intensive care units, and network 2 which supplies the medical intensive care units and the emergency room. Network 1 has been disinfected by ozonation since 1995, and network 2 has been disinfected by ionisation since 1999. The hot water temperature was increased from 50 to 65 degrees C in 1998 and 2000 in networks 1 and 2, respectively. Water samples and swabs of the water outlets were cultured for Legionella spp. between four and six times each year, providing data before and after implementation of the disinfection procedures. There was no significant difference in the proportion of samples positive for Legionella spp. after ozonation in network 1 or after ionization in network 2. In both networks, there was a significant reduction in legionella isolates after increasing the hot water temperature to 65 degrees C. Maintaining the hot water temperature above 50 degrees C throughout both networks proved to be the most effective control measure in our hospital. PMID:15823660

  13. Response of total tannins and phenolics in loblolly pine foliage exposed to ozone and acid rain.

    PubMed

    Jordan, D N; Green, T H; Chappelka, A H; Lockaby, B G; Meldahl, R S; Gjerstad, D H

    1991-03-01

    Tannin and total phenolic levels in the foliage of loblolly pine (Pinus taeda L.) were examined in order to evaluate the effect of atmospheric pollution on secondary plant metabolism. The trees were exposed to four ozone concentrations and three levels of simulated acid rain. Tannin concentration (quantity per gram) and content (quantity per fascicle) were increased in foliage exposed to high concentrations of ozone in both ozone-sensitive and ozone-tolerant families. No effect of acid rain on tannins was observed. Neither total phenolic concentration nor content was significantly affected by any treatment, indicating that the ozone-related increase in foliar tannins was due to changes in allocation within the phenolic group rather than to increases in total phenolics. The change in allocation of resources in the production of secondary metabolites may have implications in herbivore defense, as well as for the overall energy balance of the plant.

  14. Changes in stratospheric ozone.

    PubMed

    Cicerone, R J

    1987-07-01

    The ozone layer in the upper atmosphere is a natural feature of the earth's environment. It performs several important functions, including shielding the earth from damaging solar ultraviolet radiation. Far from being static, ozone concentrations rise and fall under the forces of photochemical production, catalytic chemical destruction, and fluid dynamical transport. Human activities are projected to deplete substantially stratospheric ozone through anthropogenic increases in the global concentrations of key atmospheric chemicals. Human-induced perturbations may be occurring already.

  15. Ozone studies in the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Becerra-Davila, Fernando

    obtained from this photolysis study demonstrate that the local ground level ozone formation is not only influenced by the strong solar radiation and changing aerosol makeup, but also by other heterogeneous factors and reactions. In addition, this research provided good evidence that the ground level ozone precursor regime in El Paso during the ozone episode of June 2006 was mostly VOC-limited. Much of this estimation was derived from measurements of local ambient VOC/NOx ratios. This finding shows that at least during June 2006, the non-linear surface ozone production increased during weekends compared to workdays in a habitually VOC-limited regime. The seasonal variations of columnar ozone as measured by a Multi-filter Rotating Shadowband instrument installed at the UTEP campus are analyzed for the first time for this region and results are presented. This investigation has addressed the problem of ground-level ozone formation in the Paso del Norte region. Urban ozone is a complex problem with many aspects that are not fully understood. In this investigation, a range of techniques has been used to address the study of local surface ozone episodes with the purpose of acquiring new insights and knowledge that will help understand and remediate the diverse atmospheric pollution events that affect this bi-national region recurrently. Innovative techniques were developed and used, ranging from the use of local ambient atmospheric pollution data to the utilization of complex modeling techniques to achieve the best possible computer results. Finally, the influence of ground level ozone concentrations in admissions to hospitals for this region due to respiratory diseases is analyzed. The comprehensive results obtained in this work will help to better understand ozone formation in the Paso del Norte Region for future policy regulation implementations.

  16. Relationships between mild PM10 and ozone urban air levels and spontaneous abortion: clues for primary prevention.

    PubMed

    Di Ciaula, Agostino; Bilancia, Massimo

    2015-01-01

    The effects of environmental pollution on spontaneous abortion (SAB) are still unclear. Records of SAB were collected from five cities (514,996 residents) and correlated with PM10, NO(2) and ozone levels. Median pollutant concentrations were below legal limits. Monthly SABs positively correlated with PM10 and ozone levels but not with NO(2) levels. The mean monthly SAB rate increase was estimated equal to 19.7 and 33.6 % per 10 μg/m(3) increase in PM10 or ozone concentration, respectively. Higher values of PM10 and SABs were evident in cities with- than in those without pollutant industries, with a number of SABs twofolds higher in the former group. In conclusion, SAB occurrence is affected by PM10 (particularly if industrial areas are present) and ozone concentrations, also at levels below the legal limits. Thus, SAB might be considered, at least in part, a preventable condition.

  17. Ozone hole won`t worsen?

    SciTech Connect

    Kerr, R.A.

    1995-10-20

    The timing was fitting. Last week, the chemistry Nobel Prize went to the researchers who first linked chlorine-containing pollutants with stratospheric ozone loss. And last week brought the climax in the annual drama of Antarctic ozone destruction, which begins when the spring sun triggers the ozone-depleting reactions. Satellite and balloon observations showed that the ozone hole is about as deep and wide as ever. But new computer modeling of hole formation suggests that future holes will be no larger.

  18. Ozonated olive oils and the troubles.

    PubMed

    Uysal, Bulent

    2014-01-01

    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. PMID:26401346

  19. An investigation of the effects of simulated acid rain and elevated ozone on the physiology of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings and mature trees

    SciTech Connect

    Momen, B.

    1993-12-31

    This study investigated the combined effects of simulated acid rain and ozone on foliar water relations, carbon and nitrogen contents, gas exchange, and respiration of ponderosa pine seedlings and mature trees grown in the field at the USDA Forest Service Tree Improvement Center in Chico, California. Acid rain levels (pH 5.1 and 3) were applied weekly on foliage only, from January to April, 1992. Plants were exposed to ozone levels (ambient and twice ambient) during the day only, from August to December, 1990, and from September to November, 1992. Results suggested that elevated ozone, particularly in combination with strong acid, caused osmotic adjustment that may benefit plants during drought. The observed effects of pollutants are similar to the reported effects of drought on plant water relations. Elevated ozone decreased foliar nitrogen content and thus increased the C:N ratio, particularly in seedlings. Stomatal conductance was not affected by pollutants but net photosynthesis was decreased by elevated ozone, especially in mature trees. The greater sensitivity of net photosynthesis of mature trees to elevated ozone was contrary to all other plant characteristics investigated. Elevated ozone increased seedling respiration. Under controlled, temperature, light, and vapor pressure deficit conditions, net photosynthesis responded positively to increases in plant age, light intensity, and rain pH, but negatively to increases in tissue age, heat, and ozone concentration. Overall results indicated that acid rain and elevated ozone declined the carbon pool of ponderosa pine due to increased respiration and decreased net photosynthesis. Pollutant effects were more profound in mid-summer when ozone concentrations were highest. On many occasions the effects of acid rain and ozone levels interacted. Seedlings were more sensitive to pollutants than mature trees.

  20. Impact of biogenic emissions on ozone and fine particles over Europe: Assessing the effect of temperature increase and the role of anthropogenic NOx emissions reduction

    NASA Astrophysics Data System (ADS)

    Tagaris, Efthimios; Sotiropoulou, Rafaella-Eleni P.; Gounaris, Nikos; Andronopoulos, Spyros; Vlachogiannis, Diamando

    2014-05-01

    The role of biogenic emissions on ozone and PM2.5 levels over Europe is assessed for July 2006 using the CMAQ modeling system. Biogenic emissions are simulated to increase the daily maximum 8 hour ozone (Max8hrO3) mixing ratios and to decrease PM2.5 average concentrations over Europe. Since climate change will lead to higher temperatures increasing subsequently biogenic emissions, sensitivity analysis to temperature is performed. Higher temperatures suggest an average increase in Max8hrO3 mixing ratios over Europe by about 3% and an average decrease in PM2.5 concentrations by about 6%, related to a temperature increase by 3 K degrees. Temperature increases are simulated, also, to increase the organic part of PM2.5 and to decrease the inorganic one on average over Europe. In order to examine if abatement measures for anthropogenic emissions could offset ozone increases in a warmer environment and their effect on PM2.5 concentrations, simulation with a domain wide reduction of anthropogenic NOx emissions by 10% is performed. This is estimated to reduce Max8hrO3 mixing ratios on average over Europe, however, in VOCs limited areas there is an increase. The reduction in anthropogenic NOx emissions is simulated to reduce PM2.5 concentrations on average over Europe enhancing the reduction simulated in a warmer environment but further modifying PM2.5 component concentrations. This work was supported by the National Strategic Reference Framework (NSRF) 2007-2013 grand No 09SYN-31-667.

  1. Ozone depletion and climate change: impacts on UV radiation.

    PubMed

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M; Madronich, S

    2011-02-01

    stratospheric ozone can also be affected by the increases in the concentration of GHGs, which lead to decreased temperatures in the stratosphere and accelerated circulation patterns. These changes tend to decrease total ozone in the tropics and increase total ozone at mid and high latitudes. Changes in circulation induced by changes in ozone can also affect patterns of surface wind and rainfall. The projected changes in ozone and clouds may lead to large decreases in UV at high latitudes, where UV is already low; and to small increases at low latitudes, where it is already high. This could have important implications for health and ecosystems. Compared to 1980, UV-B irradiance towards the end of the 21st century is projected to be lower at mid to high latitudes by between 5 and 20% respectively, and higher by 2-3% in the low latitudes. However, these projections must be treated with caution because they also depend strongly on changes in cloud cover, air pollutants, and aerosols, all of which are influenced by climate change, and their future is uncertain. Strong interactions between ozone depletion and climate change and uncertainties in the measurements and models limit our confidence in predicting the future UV radiation. It is therefore important to improve our understanding of the processes involved, and to continue monitoring ozone and surface UV spectral irradiances both from the surface and from satellites so we can respond to unexpected changes in the future.

  2. Ozone depletion and climate change: impacts on UV radiation.

    PubMed

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M; Madronich, S

    2011-02-01

    stratospheric ozone can also be affected by the increases in the concentration of GHGs, which lead to decreased temperatures in the stratosphere and accelerated circulation patterns. These changes tend to decrease total ozone in the tropics and increase total ozone at mid and high latitudes. Changes in circulation induced by changes in ozone can also affect patterns of surface wind and rainfall. The projected changes in ozone and clouds may lead to large decreases in UV at high latitudes, where UV is already low; and to small increases at low latitudes, where it is already high. This could have important implications for health and ecosystems. Compared to 1980, UV-B irradiance towards the end of the 21st century is projected to be lower at mid to high latitudes by between 5 and 20% respectively, and higher by 2-3% in the low latitudes. However, these projections must be treated with caution because they also depend strongly on changes in cloud cover, air pollutants, and aerosols, all of which are influenced by climate change, and their future is uncertain. Strong interactions between ozone depletion and climate change and uncertainties in the measurements and models limit our confidence in predicting the future UV radiation. It is therefore important to improve our understanding of the processes involved, and to continue monitoring ozone and surface UV spectral irradiances both from the surface and from satellites so we can respond to unexpected changes in the future. PMID:21253660

  3. Mountain cold-trapping increases transfer of persistent organic pollutants from atmosphere to cows' milk.

    PubMed

    Shunthirasingham, Chubashini; Wania, Frank; MacLeod, Matthew; Lei, Ying Duan; Quinn, Cristina L; Zhang, Xianming; Scheringer, Martin; Wegmann, Fabio; Hungerbühler, Konrad; Ivemeyer, Silvia; Heil, Fritz; Klocke, Peter; Pacepavicius, Grazina; Alaee, Mehran

    2013-08-20

    Concentrations of long-lived organic contaminants in snow, soil, lake water, and vegetation have been observed to increase with altitude along mountain slopes. Such enrichment, called "mountain cold-trapping", is attributed to a transition from the atmospheric gas phase to particles, rain droplets, snowflakes, and Earth's surface at the lower temperatures prevailing at higher elevations. Milk sampled repeatedly from cows that had grazed at three different altitudes in Switzerland during one summer was analyzed for a range of persistent organic pollutants. Mountain cold-trapping significantly increased air-to-milk transfer factors of most analytes. As a result, the milk of cows grazing at higher altitudes was more contaminated with substances that have regionally uniform air concentrations (hexachlorobenzene, α-hexachlorocyclohexane, endosulfan sulfate). For substances that have sources, and therefore higher air concentrations, at lower altitudes (polychlorinated biphenyls, γ-hexachlorocyclohexane), alpine milk has lower concentrations, but not as low as would be expected without mountain cold-trapping. Differences in the elevational gradients in soil concentrations and air-to-milk transfer factors highlight that cold-trapping of POPs in pastures is mostly due to increased gas-phase deposition as a result of lower temperatures causing higher uptake capacity of plant foliage, whereas cold-trapping in soils more strongly depends on wet and dry particle deposition. Climatic influences on air-to-milk transfer of POPs needs to be accounted for when using contamination of milk lipids to infer contamination of the atmosphere. PMID:23885857

  4. A MCM modeling study of the effects of nitryl chloride on oxidant budgets, ozone production, VOC lifetimes, and halogen recycling in polluted regions

    NASA Astrophysics Data System (ADS)

    Riedel, T. P.; Thornton, J. A.; Wolfe, G. M.; Gilman, J. B.; Kuster, W. C.; De Gouw, J. A.; Bon, D.; Vlasenko, A. L.; Li, S.; Williams, E. J.; Lerner, B. M.; Veres, P. R.; Roberts, J. M.

    2012-12-01

    Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing particles. Nitryl chloride is photolyzed during the day to liberate highly reactive chlorine atoms. This chemistry takes place primarily in urban environments where the concentrations of N2O5 precursors (NOx and ozone) are high, though it can likely occur in remote regions at lower intensity. Recent field measurements have illustrated the potential importance of ClNO2 as a chlorine atom source and a NOx reservoir. However, the fate of these chlorine atoms and the overall impact of ClNO2 remain unclear. To this end we have incorporated ClNO2 production, photolysis, and subsequent Cl-atom reactions into an existing Master Chemical Mechanism (MCM version 3.2) based model framework. Cl-atom reactions with alkenes and alcohols not presently part of the MCM have also been added. Using observational constraints from the CalNex 2010 field study, we assess the dominant reactive sinks and sources of chlorine atoms over the course of a model day. Relative to model runs excluding ClNO2 formation, the presence of ClNO2 produces marked changes on a variety of species important to tropospheric chemistry and air quality (e.g. O3, RO2, OH, HO2, ClOx). For example a 50% yield of ClNO2 (max ClNO2 of 1.5 ppb) from nighttime N2O5 reactions leads to a ~10% enhancement in integrated ozone production. VOC and NOx lifetimes are shorter due primarily to enhanced OH from propagation of RO2 produced by Cl-atom chemistry under high NOx. The impact of ClNO2 on daytime halogen atom recycling is substantial, with order of magnitude higher daytime Cl2 production predicted with ClNO2 chemistry than without. In fact, incorporation of ClNO2 could help explain daytime levels of Cl2 observed in polluted coastal regions. Additionally, we highlight a set of chlorinated VOC oxidation products that are predicted to form at small, but potentially detectable levels in regions with similar VOC

  5. Exposure to Persistent Organic Pollutants Increases Hospitalization Rates for Myocardial Infarction with Comorbid Hypertension

    PubMed Central

    Sergeev, Alexander V.; Carpenter, David O.

    2010-01-01

    Studies suggest that environmental exposure to persistent organic pollutants (POPs) may be an emerging risk factor for ischemic heart disease, including acute myocardial infarction (AMI). However, some studies indicate that exposure to POPs may also be a risk factor for hypertension, a well-established risk factor for AMI. To investigate effect of POPs on the environmental burden of cardiovascular disease, a study of AMI with comorbid hypertension in populations environmentally exposed to persistent organic pollutants, based on the zip code of residence, was conducted. Data on hospital discharges for AMI with comorbid hypertension were obtained from the New York Statewide Planning and Research Cooperative System for 1993–2004. Patients residing in zip codes containing or abutting POPs contaminated sites were considered environmentally exposed. Relative risks (RR) — with corresponding 95% confidence intervals (95% CI) — of hospitalization for AMI with comorbid hypertension were estimated by Poisson regression, adjusting for known confounders. Adjusted hospitalization rates for AMI with comorbid hypertension were 12.4% higher in populations residing in proximity to a POPs site (adjusted RR = 1.124, 95% CI 1.025–1.233, p < 0.05), compared to not in proximity to a POPs site. Also, hospitalization rates for AMI with comorbid hypertension were higher in males than in females (adjusted RR = 2.157, 95% CI 2.100–2.215, p < 0.05), in African Americans than in Caucasians (adjusted RR = 1.631, 95% CI 1.483–1.794, p < 0.05), and in older age groups (p for trend <0.05). These findings are consistent with the established effects of non-modifiable risk factors and serve as indirect quality indicators for our model. In conclusion, our results support the hypothesis that environmental exposure to POPs increases the burden of cardiovascular disease in exposed populations. PMID:21562627

  6. Exposure to Persistent Organic Pollutants Increases Hospitalization Rates for Myocardial Infarction with Comorbid Hypertension.

    PubMed

    Sergeev, Alexander V; Carpenter, David O

    2010-03-23

    Studies suggest that environmental exposure to persistent organic pollutants (POPs) may be an emerging risk factor for ischemic heart disease, including acute myocardial infarction (AMI). However, some studies indicate that exposure to POPs may also be a risk factor for hypertension, a well-established risk factor for AMI. To investigate effect of POPs on the environmental burden of cardiovascular disease, a study of AMI with comorbid hypertension in populations environmentally exposed to persistent organic pollutants, based on the zip code of residence, was conducted. Data on hospital discharges for AMI with comorbid hypertension were obtained from the New York Statewide Planning and Research Cooperative System for 1993-2004. Patients residing in zip codes containing or abutting POPs contaminated sites were considered environmentally exposed. Relative risks (RR) - with corresponding 95% confidence intervals (95% CI) - of hospitalization for AMI with comorbid hypertension were estimated by Poisson regression, adjusting for known confounders. Adjusted hospitalization rates for AMI with comorbid hypertension were 12.4% higher in populations residing in proximity to a POPs site (adjusted RR = 1.124, 95% CI 1.025-1.233, p < 0.05), compared to not in proximity to a POPs site. Also, hospitalization rates for AMI with comorbid hypertension were higher in males than in females (adjusted RR = 2.157, 95% CI 2.100-2.215, p < 0.05), in African Americans than in Caucasians (adjusted RR = 1.631, 95% CI 1.483-1.794, p < 0.05), and in older age groups (p for trend <0.05). These findings are consistent with the established effects of non-modifiable risk factors and serve as indirect quality indicators for our model. In conclusion, our results support the hypothesis that environmental exposure to POPs increases the burden of cardiovascular disease in exposed populations.