Pollution in the air is linked to the birth of underweight newborns

In a new study, published in Environmental Health Perspectives this week, shows that high levels of pollution are linked to smaller babies. The study looked at levels of particulate mater (PM) in the United States, Korea and Brazil and correlated it to the weight of newborns.  From Scientific American:

By the authors’ calculations, each increase in PM₁₀ by 10 micrograms per cubic meter (μg m^–3) was associated with a 3% higher chance of an infant being underweight and with an overall average weight reduced by 3 grams. That reduction in average weight tripled to 9 g when the authors adjusted for local variables such as maternal age or tobacco use. The calculations took socioeconomic status into account.

The median PM₁₀ value varied across the 14 sites, from 12.5 μg m^–3 in Vancouver to 66.5 μg m^–3 in Seoul. For a subset of centers that included information on PM_2.5exposure, the odds of lower birth weight increased by 10% for each increase in exposure.

As Trasande explains, the risks are small at the individual level, but “on a population basis, a shift can produce large increases in the percentage of low-birth-weight infants”, he says. Smoking, alcohol and drug use and poor maternal health are also linked to low birth weights.

In a study of more than 220,000 US births published last month, Trasande and his colleagues found that outdoor air pollution was associated with longer hospital stays and greater health-care costs. In 2010, 8.2% of infants born in the United States were of low birth weight.