Women who are exposed to air pollution generated by cars, power plants, and heating and cooling systems are more likely to have a baby that is born underweight, according to new research published this week in the journal Environmental Health Perspectives.
Low birth weight—defined as anything below 5.5 pounds—is linked to negative outcomes for babies, including increased mortality, chronic health problems, and stunted mental and physical development. The study, which is billed as the largest survey to date, looked at birth weight data on 3 million births recorded at 14 sites in nine different countries (across North America, South America, Europe, Asia and Australia). Researchers analyzed ambient air quality data for the area during the woman’s pregnancy. They found that in the places places they studied, “the higher the pollution rate, the greater the rate of low birth weight.”