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Associations between ozone and morbidity using the Spatial Synoptic Classification system.

Hanna AF, Yeatts KB, Xiu A, Zhu Z, Smith RL, Davis NN, Talgo KD, Arora G, Robinson PJ, Meng Q, Pinto JP - Environ Health (2011)

Bottom Line: In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions.Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses.Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for the Environment, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. ahanna@unc.edu

ABSTRACT

Background: Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina.

Methods: Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS), which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions.

Results: Ozone was associated with asthma under dry tropical (1- to 5-day lags), transitional (3- and 4-day lags), and extreme moist tropical (0-day lag) air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses.

Conclusions: Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain synoptic circulation patterns/air masses in conjunction with ambient ozone levels were associated with increased asthma and MI hospitalizations.

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Related in: MedlinePlus

Daily maximum 1-hour ozone concentrations (during the ozone season, April-September) for (a) Asheville, (b) Charlotte, (c) Greensboro, (d) Raleigh, and (e) Wilmington. The solid line represents a simple natural spline smoother to highlight the overall trend.
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Figure 1: Daily maximum 1-hour ozone concentrations (during the ozone season, April-September) for (a) Asheville, (b) Charlotte, (c) Greensboro, (d) Raleigh, and (e) Wilmington. The solid line represents a simple natural spline smoother to highlight the overall trend.

Mentions: Daily maximum 1-hour ozone time series (1996-2004) for the five cities are shown in Figure 1; the data are plotted for the ozone season (April through September). The figure shows pronounced summer maxima measured in all of the cities, although the magnitude of the seasonal variation varies from city to city. In addition, maximum O3 concentrations are typically above 100 ppb, except in Asheville. Table 1 shows the annual 95th percentile for the data for each city. In general, the larger urban areas of Charlotte, Raleigh, and Greensboro have more days with daily maximum 1-hour ozone exceeding 100 ppb than do Wilmington and Asheville. The years 2003 and 2004 show lower daily maximum 1-hour ozone values for the five cities compared to other years. These lower values could be related to large-scale patterns, as 2003 was an El Niño year. However, 1997 was also an El Niño year, but does not show lower values, even though the El Niño that year was stronger. Other factors such as changes in emissions might also be involved.


Associations between ozone and morbidity using the Spatial Synoptic Classification system.

Hanna AF, Yeatts KB, Xiu A, Zhu Z, Smith RL, Davis NN, Talgo KD, Arora G, Robinson PJ, Meng Q, Pinto JP - Environ Health (2011)

Daily maximum 1-hour ozone concentrations (during the ozone season, April-September) for (a) Asheville, (b) Charlotte, (c) Greensboro, (d) Raleigh, and (e) Wilmington. The solid line represents a simple natural spline smoother to highlight the overall trend.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3117763&req=5

Figure 1: Daily maximum 1-hour ozone concentrations (during the ozone season, April-September) for (a) Asheville, (b) Charlotte, (c) Greensboro, (d) Raleigh, and (e) Wilmington. The solid line represents a simple natural spline smoother to highlight the overall trend.
Mentions: Daily maximum 1-hour ozone time series (1996-2004) for the five cities are shown in Figure 1; the data are plotted for the ozone season (April through September). The figure shows pronounced summer maxima measured in all of the cities, although the magnitude of the seasonal variation varies from city to city. In addition, maximum O3 concentrations are typically above 100 ppb, except in Asheville. Table 1 shows the annual 95th percentile for the data for each city. In general, the larger urban areas of Charlotte, Raleigh, and Greensboro have more days with daily maximum 1-hour ozone exceeding 100 ppb than do Wilmington and Asheville. The years 2003 and 2004 show lower daily maximum 1-hour ozone values for the five cities compared to other years. These lower values could be related to large-scale patterns, as 2003 was an El Niño year. However, 1997 was also an El Niño year, but does not show lower values, even though the El Niño that year was stronger. Other factors such as changes in emissions might also be involved.

Bottom Line: In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions.Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses.Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for the Environment, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. ahanna@unc.edu

ABSTRACT

Background: Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina.

Methods: Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS), which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions.

Results: Ozone was associated with asthma under dry tropical (1- to 5-day lags), transitional (3- and 4-day lags), and extreme moist tropical (0-day lag) air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses.

Conclusions: Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain synoptic circulation patterns/air masses in conjunction with ambient ozone levels were associated with increased asthma and MI hospitalizations.

Show MeSH
Related in: MedlinePlus