Air Pollution Linked to Lower Birth Weights

Air pollution, even at relatively low levels, is associated with a significant increase in the risk for low-birth-weight babies, a new study has found.

European researchers pooled data from 14 studies that included more than 74,000 mother-child pairs in 12 countries. The scientists also estimated concentrations of airborne particulate matter at the mothers’ home addresses during their pregnancies.

Concentrations of particulate matter as low as 20 micrograms per cubic meter were linked to an increased risk of giving birth to a full-term low-birth-weight baby, the researchers found. After controlling for a variety of factors, the scientists estimated that each 5 microgram per cubic meter increase in particulate matter was associated with an 18 percent increase in the risk for low birth weight.

Over all, they estimate, a reduction in particulate matter levels to 10 micrograms per cubic meter would lead to a 22 percent decrease in the number of low-birth-weight infants in these countries. The report appears online in The Lancet Respiratory Medicine.

“We have evidence from animal studies that the tiniest particles enter the bloodstream and go to the fetus,” said the senior author, Rémy Slama, a senior investigator at the Institute of Health and Medical Research in Grenoble, France. “Can we expect other health effects in these children? There are hints that there might be — low birth weight is a marker of negative effects in adulthood.”