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Relation of peak expiratory flow rates and symptoms to ambient ozone
M Krzyzanowski1, J J Quackenboss, M D Lebowitz
1Division of Respiratory Sciences, University of Arizona Health Sciences Center, Tucson.
Insights
High ozone levels significantly reduce lung function, especially in children and adults with asthma. This acute respiratory response worsens with increased temperature and particulate matter.
Area of Science:
- Environmental Health
- Respiratory Medicine
- Epidemiology
Background:
- Ambient ozone (O3) is a known respiratory irritant.
- Asthma exacerbations are often linked to air pollution.
- Understanding the acute effects of O3 on lung function is crucial for public health.
Purpose of the Study:
- To investigate the temporal relationship between ambient ozone concentrations and peak expiratory flow rates (PEFRs) in children and adults.
- To identify susceptible populations, particularly those with asthma.
- To explore the influence of co-pollutants and meteorological factors.
Main Methods:
- Prospective study involving 287 children and 523 adults in Tucson.
- Daily measurements of PEFRs were collected and correlated with ambient O3 levels.
- Statistical models adjusted for covariates, including particulate matter (PM10) and temperature.
Main Results:
- Lower noon PEFRs were observed in children on high O3 days, with the greatest impact on asthmatic children.
- Significant associations between O3 and reduced evening PEFRs were found in children and adults with asthma.
- Interactions between O3, PM10, and temperature significantly affected daily PEFRs.
Conclusions:
- Low-level ambient ozone exposure has an acute adverse effect on respiratory function, particularly in individuals with asthma.
- The respiratory response to ozone is exacerbated by higher temperatures and particulate matter concentrations.
- These findings highlight the need for air quality monitoring and protective measures, especially for vulnerable populations.
Abstract:
The temporal association between peak expiratory flow rates (PEFRs) and ambient ozone (O3) was studied in a group of 287 children and 523 nonsmoking adults in Tucson. In children, noon PEFRs were decreased on days when there was a higher O3 concentration; children with physician-confirmed asthma experienced the greatest decrease in noon PEFR. Evening PEFR levels were also significantly related to O3 in children, especially asthmatics. Among adults, evening PEFRs were decreased in asthmatics who spent more time outdoors on days when O3 levels were higher. After we adjusted for covariates, significant effects of interactions of 8-h O3 levels with particulate matter (PM10) and temperature on daily PEFR were found. There was some overnight effect of 8-h O3 on morning PEFRs. In general, the respiratory response to low-level ambient O3 is acute, occurs more in asthmatics, and increases as temperature and PM10 increase.