Research
Effects of air pollution on neonatal prematurity in guangzhou of china: a time-series study
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* Corresponding authors: Qingguo Zhao zqgfrost@126.com - Yukai Du duyukai100@yahoo.com.cn
1 College of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, PR China
2 Guangdong Women and Children Health Hospital, Guangzhou 510010, Guangdong, PR China
Environmental Health 2011, 10:2 doi:10.1186/1476-069X-10-2
Published: 10 January 2011Abstract
Background
Over the last decade, a few studies have investigated the possible adverse effects of ambient air pollution on preterm birth. However, the correlation between them still remains unclear, due to insufficient evidences.
Methods
The correlation between air pollution and preterm birth in Guangzhou city was examined by using the Generalized Additive Model (GAM) extended Poisson regression model in which we controlled the confounding factors such as meteorological factors, time trends, weather and day of the week (DOW). We also adjusted the co linearity of air pollutants by using Principal Component Analysis. The meteorological data and air pollution data were obtained from the Meteorological Bureau and the Environmental Monitoring Centre, while the medical records of newborns were collected from the perinatal health database of all obstetric institutions in Guangzhou, China in 2007.
Results
In 2007, the average daily concentrations of NO2, PM10 and SO2 in Guangzhou, were 61.04, 82.51 and 51.67 μg/m3 respectively, where each day an average of 21.47 preterm babies were delivered. Pearson correlation analysis suggested a negative correlation between the concentrations of NO2, PM10, SO2, and temperature as well as relative humidity. As for the time-series GAM analysis, the results of single air pollutant model suggested that the cumulative effects of NO2, PM10 and SO2 reached its peak on day 3, day 4 and day 3 respectively. An increase of 100 μg/m3 of air pollutants corresponded to relative risks (RRs) of 1.0542 (95%CI: 1.0080 ~1.1003), 1.0688 (95%CI: 1.0074 ~1.1301) and 1.1298 (95%CI: 1.0480 ~1.2116) respectively. After adjusting co linearity by using the Principal Component Analysis, the GAM model of the three air pollutants suggested that an increase of 100 μg/m3 of air pollutants corresponded to RRs of 1.0185 (95%CI: 1.0056~1.0313), 1.0215 (95%CI: 1.0066 ~1.0365) and 1.0326 (95%CI: 1.0101 ~1.0552) on day 0; and RRs of the three air pollutants, at their strongest cumulative effects, were 1.0219 (95%CI: 1.0053~1.0386), 1.0274 (95%CI: 1.0066~1.0482) and 1.0388 (95%CI: 1.0096 ~1.0681) respectively.
Conclusions
This study indicates that the daily concentrations of air pollutants such as NO2, PM10 and SO2 have a positive correlation with the preterm births in Guangzhou, China.