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Ambient ozone exposure and children's acute asthma in New York City: a case-crossover analysis.

Sheffield PE, Zhou J, Shmool JL, Clougherty JE - Environ Health (2015)

Bottom Line: We did not observe significant modification by age for boys.Boys exhibited a more prompt response (lag day 1) to ozone than did girls (lag day 3), but significant associations for girls were retained longer, through lag day 6.Differences in ozone response for boys and girls, before and after puberty, may point towards both social (gendered) and biological (sex-linked) sources of effect modification.

View Article: PubMed Central - PubMed

Affiliation: Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl., Box 1057, DPM, New York, NY, 10029, USA. perry.sheffield@mssm.edu.

ABSTRACT

Background: Childhood asthma morbidity has been associated with ambient ozone in case-crossover studies. Varying effects of ozone by child age and sex, however, have been less explored.

Methods: This study evaluates associations between ozone exposure and asthma emergency department visits and hospitalizations among boys and girls aged 5-17 years in New York City for the 2005-2011 warm season period. Time-stratified case-crossover analysis was conducted and, for comparison, time-series analysis controlling for season, day-of-week, same-day and delayed effects of temperature and relative humidity were also performed.

Results: We found associations between ambient ozone levels and childhood asthma emergency department visits and hospitalizations in New York City, although the relationships varied among boys and girls and by age group. For an increase of interquartile range (0.013 ppm) in ozone, there was a 2.9-8.4% increased risk for boys and 5.4-6.5% for girls in asthma emergency department visits; and 8.2% increased risk for girls in hospitalizations. Among girls, we observed stronger associations among older children (10-13 and 14-17 year age groups). We did not observe significant modification by age for boys. Boys exhibited a more prompt response (lag day 1) to ozone than did girls (lag day 3), but significant associations for girls were retained longer, through lag day 6.

Conclusions: Our study indicates significant variance in associations between short-term ozone concentrations and asthma events by child sex and age. Differences in ozone response for boys and girls, before and after puberty, may point towards both social (gendered) and biological (sex-linked) sources of effect modification.

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Related in: MedlinePlus

Percent excess asthma hospitalization risk in NYC children per interquartile range of ozone concentration. Point denotes non-significant association; diamond denotes positive significant association; triangle denotes negative significant association.
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Fig2: Percent excess asthma hospitalization risk in NYC children per interquartile range of ozone concentration. Point denotes non-significant association; diamond denotes positive significant association; triangle denotes negative significant association.

Mentions: The risk of asthma hospitalization was significantly associated with ozone only for girls (5-17 years) (FigureĀ 2); for an IQR increase in ozone, we observed significant excess risk of 8.2% (95% CI: 1.1%, 15.8%) on lag day 2. In analyses stratified by both age and sex, negative associations were observed for boys in age group 5-9 years on lag days 1 and 2. Significant associations were observed among girls aged 10-17 years. The highest excess risk for asthma hospitalization was found among girls aged 10-13 years on lag day 2 [21.5% (95% CI: 6.6%, 38.6%)].Figure 2


Ambient ozone exposure and children's acute asthma in New York City: a case-crossover analysis.

Sheffield PE, Zhou J, Shmool JL, Clougherty JE - Environ Health (2015)

Percent excess asthma hospitalization risk in NYC children per interquartile range of ozone concentration. Point denotes non-significant association; diamond denotes positive significant association; triangle denotes negative significant association.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4373115&req=5

Fig2: Percent excess asthma hospitalization risk in NYC children per interquartile range of ozone concentration. Point denotes non-significant association; diamond denotes positive significant association; triangle denotes negative significant association.
Mentions: The risk of asthma hospitalization was significantly associated with ozone only for girls (5-17 years) (FigureĀ 2); for an IQR increase in ozone, we observed significant excess risk of 8.2% (95% CI: 1.1%, 15.8%) on lag day 2. In analyses stratified by both age and sex, negative associations were observed for boys in age group 5-9 years on lag days 1 and 2. Significant associations were observed among girls aged 10-17 years. The highest excess risk for asthma hospitalization was found among girls aged 10-13 years on lag day 2 [21.5% (95% CI: 6.6%, 38.6%)].Figure 2

Bottom Line: We did not observe significant modification by age for boys.Boys exhibited a more prompt response (lag day 1) to ozone than did girls (lag day 3), but significant associations for girls were retained longer, through lag day 6.Differences in ozone response for boys and girls, before and after puberty, may point towards both social (gendered) and biological (sex-linked) sources of effect modification.

View Article: PubMed Central - PubMed

Affiliation: Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl., Box 1057, DPM, New York, NY, 10029, USA. perry.sheffield@mssm.edu.

ABSTRACT

Background: Childhood asthma morbidity has been associated with ambient ozone in case-crossover studies. Varying effects of ozone by child age and sex, however, have been less explored.

Methods: This study evaluates associations between ozone exposure and asthma emergency department visits and hospitalizations among boys and girls aged 5-17 years in New York City for the 2005-2011 warm season period. Time-stratified case-crossover analysis was conducted and, for comparison, time-series analysis controlling for season, day-of-week, same-day and delayed effects of temperature and relative humidity were also performed.

Results: We found associations between ambient ozone levels and childhood asthma emergency department visits and hospitalizations in New York City, although the relationships varied among boys and girls and by age group. For an increase of interquartile range (0.013 ppm) in ozone, there was a 2.9-8.4% increased risk for boys and 5.4-6.5% for girls in asthma emergency department visits; and 8.2% increased risk for girls in hospitalizations. Among girls, we observed stronger associations among older children (10-13 and 14-17 year age groups). We did not observe significant modification by age for boys. Boys exhibited a more prompt response (lag day 1) to ozone than did girls (lag day 3), but significant associations for girls were retained longer, through lag day 6.

Conclusions: Our study indicates significant variance in associations between short-term ozone concentrations and asthma events by child sex and age. Differences in ozone response for boys and girls, before and after puberty, may point towards both social (gendered) and biological (sex-linked) sources of effect modification.

Show MeSH
Related in: MedlinePlus