Smog and Birth Weight

The World Health Organization has classified low birth weight as a risk factor for adult cardiovascular disease. Air pollution is a modifiable factor that may affect birth weight. The effects of maternal exposure to air pollution in pregnancy on birth weight are difficult to identify comprehensively and specifically because of social inequalities in exposure to pollutants and birth weight as well as co- occurrence of pollutants. To fill this gap Professor Schooling and colleague applied a new statistical technique (partial least squares) in a unique birth cohort with little social patterned of birth weight to assess simultaneously the effects of several air pollutants on birth weight. This study showed that PM₁₀ (particles less than 10 microns in diameter) and NO₂ (nitrogen dioxide) reduced both birth weight and gestational age.

In summary, Professor Schooling says, “This study offers convincing proof of potentially life long harms to the baby from maternal exposure during pregnancy to air pollutants PM₁₀ (particles are less than 10 microns in diameter) and NO₂.”

Huang JV, Leung GM, Schooling CM, The association of air pollution with birth weight and gestational age: evidence from Hong Kong’s “Children of 1997” birth cohort, J Public Health, epub 29^th July 2016