TITLE:
Is Air Pollution a Risk Factor for Low Birth Weight in Ulaanbaatar, Mongolia?
AUTHORS:
Gantuya Dorji, Angarmurun Dayan, Khuderchuluun Nanjid, Undram Lkhagvaa, Chimedsuren Оchir
KEYWORDS:
Low Birth Weight, Carbon Monoxide, Nitrogen Dioxide, Sulfur Dioxide, Particulate Matter, Ulaanbaatar, Pollution
JOURNAL NAME:
Open Access Library Journal,
Vol.1 No.8,
November
24,
2014
ABSTRACT: Ulaanbaatar (Mongolia) is one of the most air polluted capital cities in the world, with ambient sulfide dioxide (SO2) and particulate matter PM10 and PM 2.5 levels > 23 times World Health Organization (WHO) standards in winter. Several studies have examined the effects of air pollution on pregnancy, providing that exposure to ambient air pollutants is associated with poor birth outcome, such as low birth weight. Our study goal was to study the associations between air pollution exposures during pregnancy and low birth weight among all full-term births (gestational age 37 - 42 weeks) for a 6-year period (January 2008 through December 31, 2013) in Ulaanbaatar, Mongolia. In the study we recruited 160,676 singletons. We used a logistic regression adjusting for gestational age, parental education level, parity and infant age. The adjusted relative risk of low birth weight was 1.06 (95% CI = 1.01 - 1.12) for each inter-quartile increase in NO2 concentrations. The risk of low birth weight was increased to 1.04 (95% CI = 0.93 - 1.15) for CO, 1.02 (95% CI 0.97 - 1.05) for SO2 and 1.03 (95% CI 1.01 - 1.08) for PM10. Each inter-quartile increase of NO2 concentration during the first trimester reduced 10.74 gm of birth weight. SO2, CO and PM10 also decreased birth weight 7.62, 7.49, and 8.72 gm, respectively. Each inter-quartile increase of pollutants decreases baby weight up to 11 grams.