Long-Term Air Pollution Exposure and Blood Pressure in the Sister Study.
BACKGROUND
Exposure to air pollution has been consistently associated with cardiovascular morbidity and mortality, but mechanisms remain uncertain. Associations with blood pressure (BP) may help to explain the cardiovascular effects of air pollution.


OBJECTIVE
We examined the cross-sectional relationship between long-term (annual average) residential air pollution exposure and BP in the National Institute of Environmental Health Sciences' Sister Study, a large U.S. cohort study investigating risk factors for breast cancer and other outcomes.


METHODS
This analysis included 43,629 women 35-76 years of age, enrolled 2003-2009, who had a sister with breast cancer. Geographic information systems contributed to satellite-based nitrogen dioxide (NO2) and fine particulate matter (≤ 2.5 μm; PM2.5) predictions at participant residences at study entry. Generalized additive models were used to examine the relationship between pollutants and measured BP at study entry, adjusting for cardiovascular disease risk factors and including thin plate splines for potential spatial confounding.


RESULTS
A 10-μg/m(3) increase in PM2.5 was associated with 1.4-mmHg higher systolic BP (95% CI: 0.6, 2.3; p < 0.001), 1.0-mmHg higher pulse pressure (95% CI: 0.4, 1.7; p = 0.001), 0.8-mmHg higher mean arterial pressure (95% CI: 0.2, 1.4; p = 0.01), and no significant association with diastolic BP. A 10-ppb increase in NO2 was associated with a 0.4-mmHg (95% CI: 0.2, 0.6; p < 0.001) higher pulse pressure.


CONCLUSIONS
Long-term PM2.5 and NO2 exposures were associated with higher blood pressure. On a population scale, such air pollution-related increases in blood pressure could, in part, account for the increases in cardiovascular disease morbidity and mortality seen in prior studies.
Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA.
Stephanie H
SH
Chan
Victor C
VC
Van Hee
Silas
S
Bergen
Adam A
AA
Szpiro
Lisa A
LA
DeRoo
Stephanie J
SJ
London
Julian D
JD
Marshall
Joel D
JD
Kaufman
Dale P
DP
Sandler
D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects*; D001794:Blood Pressure / Q000187:drug effects*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000633:toxicity*; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012621:Seasons; D014481:United States
D000393:Air Pollutants; D052638:Particulate Matter; D009585:Nitrogen Dioxide