Seasonal variation of effect of air pollution on blood pressure.
BACKGROUND
Many studies have shown a consistent association between ambient air pollution and an increase in death due to cardiovascular causes. An increase in blood pressure is a common risk factor for a variety of cardiovascular diseases. However, the association between air pollution and blood pressure has not been evaluated extensively.


METHODS
In this cross-sectional study, we measured blood pressure in 10,459 subjects who had a health examination from 2001 to 2003, and calculated individual's exposure to ambient levels of air pollutants. To evaluate the relationship between exposure to air pollutants and blood pressure with respect to season, we performed a multiple regression analysis, separately, according to season, controlling for individual characteristics and meteorological variables.


RESULTS
In the warm-weather season (July-September), particulate air pollutant of <10 microm (PM(10)) and nitrogen dioxide (NO(2)) concentrations were significantly associated with measures of blood pressure. During cold weather (October-December), blood pressure was significantly associated with sulphur dioxide (SO(2)) and ozone (O(3)) concentrations. The significant association between PM(10) or NO(2) and blood pressure disappeared during the cold-weather season.


CONCLUSIONS
We found a seasonal variation for the association between ambient air-pollutant concentrations and blood pressure.
Choi
Ji-Ho
JH
Department of Preventive Medicine, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, South Korea.
Xu
Qing-Song
QS
Park
So-Yeon
SY
Kim
Jin-Hee
JH
Hwang
Seung-Sik
SS
Lee
Kwan-Hee
KH
Lee
Hyun-Jung
HJ
Hong
Yun-Chul
YC
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution / Q000009:adverse effects*; D001794:Blood Pressure / Q000502:physiology*; D003080:Cold Temperature; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010083:Oxidants, Photochemical / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D012621:Seasons
D000393:Air Pollutants; D010083:Oxidants, Photochemical; D052638:Particulate Matter; D010126:Ozone; D009585:Nitrogen Dioxide