Exposure to air pollution and meteorological factors associated with children's primary care visits at night due to asthma attack: case-crossover design for 3-year pooled patients.
OBJECTIVE
We examined the association of outdoor air pollution and meteorological parameters with primary care visits (PCVs) at night due to asthma attack.


METHODS
A case-crossover study was conducted in a primary care clinic in Himeji City, Japan.


METHODS
Participants were 1447 children aged 0-14 years who visited the clinic with an asthma attack from April 2010 until March 2013.


METHODS
Daily concentrations of air pollutants and meteorological parameters were measured.


METHODS
PCVs at night due to asthma attack. A conditional logistic regression model was used to estimate ORs of PCVs per unit increment of air pollutants or meteorological parameters (the per-unit increments of particulate matter with an aerodynamic diameter ≤2.5 µm (PM₂.₅) and ozone were 10 μg/m(3) and 10 ppb, respectively). Analyses took into consideration the effects of seasonality.


RESULTS
We noted an association between PCVs and daily ozone levels on the day before a PCV (OR=1.17; 95% CI 1.01 to 1.35; p=0.04), as well as between PCVs and 3-day mean ozone levels before a PCV (OR=1.29; 95% CI 1.00 to 1.46; p=0.04), from April until June. We also observed an association between PCVs and daily PM₂.₅ levels on the day before a PCV from December until March (OR=1.16; 95% CI 1.01 to 1.33; p=0.05). Meteorological parameters, such as hours of sunshine from September until November, atmospheric pressure from April until June, and temperature from April until August, were also found to be associated with PCVs.


CONCLUSIONS
The findings in the present study supported an association between ozone and PCVs and suggest that certain meteorological items may be associated with PCVs.
Department of Environmental Epidemiology, National Institute for Environmental Studies, Tsukuba, Japan Department of Healthcare Epidemiology, Kyoto University School of Public Health, Kyoto, Japan.
Shin
S
Yamazaki
Department of Public Health, Hyogo College of Medicine, Nishinomiya, Japan.
Masayuki
M
Shima
Department of Public Health, Hyogo College of Medicine, Nishinomiya, Japan.
Yoshiko
Y
Yoda
Himeji Medical Association, Himeji, Japan.
Katsumi
K
Oka
Himeji Medical Association, Himeji, Japan.
Fumitake
F
Kurosaka
Himeji Medical Association, Himeji, Japan.
Shigeta
S
Shimizu
Himeji Medical Association, Himeji, Japan.
Hironobu
H
Takahashi
Himeji Medical Association, Himeji, Japan.
Yuji
Y
Nakatani
Himeji Medical Association, Himeji, Japan.
Jittoku
J
Nishikawa
Himeji Medical Association, Himeji, Japan.
Katsuhiko
K
Fujiwara
Himeji Medical Association, Himeji, Japan.
Yasuyuki
Y
Mizumori
Himeji Medical Association, Himeji, Japan.
Akira
A
Mogami
Himeji Medical Association, Himeji, Japan.
Taku
T
Yamada
Himeji Medical Association, Himeji, Japan.
Nobuharu
N
Yamamoto
D000293:Adolescent; D039602:After-Hours Care / Q000706:statistics & numerical data*; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D001274:Atmospheric Pressure; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D011320:Primary Health Care / Q000706:statistics & numerical data*; D014887:Weather
D052638:Particulate Matter; D010126:Ozone
PUBLIC HEALTH