This study aimed to assess if air pollutants and meteorological factors synergistically affect birth outcomes in Shenzhen, China.

A total of 1,206,158 singleton live births between 2005 and 2012 were identified from a birth registry database. Daily average measurements of particulate matter ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ambient air temperature (T), and dew point temperature (Td), a marker of humidity, were collected. Multivariable logistic regression models were used to evaluate associations between air pollution and small for gestational age (SGA), and full-term low birth weight (TLBW). We classified births into those conceived in the warm (May-October) and cold seasons (November-April) and then estimated interactions between air pollutants and meteorological factors.

An interquartile range (IQR) increase in PM10 exposure during the first trimester (23.1 µg/m) and NO2 during both the first and second trimesters (15.1 and 13.4 µg/m) was associated with SGA and TLBW risk; odds ratios ranged from 1.01 (95% confidence interval [CI] = 1.00, 1.02) to 1.09 (1.07, 1.12). We observed interactive effects of both air temperature and humidity on PM10 and SGA for newborns conceived in the warm season. Each IQR increase in PM10 (11.1 µg/m) increased SGA risk by 90% (95% CI = 19%, 205%), 29% (23, 34%), 61% (10, 38%), and 26% (21, 32%) when T < 5th percentile, 5th < T < 95th percentile, Td < 5th percentile, and 5th < Td < 95th percentile, respectively.

Investigators: Wang, Qiong, Liang, Qianhong, Li, Changchang, Ren, Meng, Lin, Shao, Knibbs, Luke D., Zhang, Huanhuan, Gong, Wei, Bao, Junzhe, Wang, Suhan, Wang, Xuemei, Zhao, Qingguo, Huang, Cunrui


  • National Key R&D Program of China
  • National Natural Science Foundation of China
  • Medical Scientific Research Foundation of Guangdong Province
  • Nature Science Foundation of Guangdong Province
  • Asia-Pacific Network for Global Change Research

Project members

Associate Professor Luke Knibbs

Associate Professor
School of Public Health