Positive association between short-term ambient air pollution exposure and children blood pressure in China-Result from the Seven Northeast Cities (SNEC) study.

The impact of ambient air pollution on health causes concerns in China. However, little is known about the association of short-term air pollution exposure with blood pressure (BP) in children. The goal of present study was to assess the association between short-term air pollution and BP in children from a highly polluted area in China. This study enrolled 9354 children in 24 elementary and middle schools (aged 5-17 years) from the Seven Northeast Cities (SNEC) study, respectively, during the period of 2012-2013. Ambient air pollutants, including particulate matter with an aerodynamic diameter of ≤10 μm (PM), sulfur dioxide (SO), nitrogen dioxide (NO) and ozone (O) on the days (1-5 days) preceding BP examination were collected from local air monitoring stations. Generalized additive models and two-level regression analyses were used to evaluate the relationship between air pollution and BP after adjusting for other covariates. Results showed that with an interquartile range (IQR) increase in PM (50.0 μg/m) and O (53.0 μg/m) level during the 5-day mean exposure, positive associations with elevated BP were observed, with an odds ratio of 2.17 (95% CI, 1.61-2.93) for PM and 2.77 (95% CI, 1.94-3.95) for O. Both systolic BP and diastolic BP levels were positively associated with an IQR increase of four air pollutants at different lag times. Specifically, an IQR increase in the 5-day mean of PM and O was associated with elevation of 2.07 mmHg (95% CI, 1.71-2.44) and 3.29 mmHg (95% CI, 2.86-3.72) in systolic BP, respectively. When stratified by sex, positive relationships were observed for elevated BP with NO exposure only in males. This is the first report on the relationship between ambient short-term air pollution exposure and children BP in China. Findings indicate a need to control air pollutants and protect children from heavy air pollution exposure in China.