Children born in New York City scored higher on early thinking and learning tests as the air their mothers breathed during pregnancy became cleaner, according to a 20-year study. Researchers at Columbia University's Mailman School of Public Health published the results in the journal Environmental Health.
Two decades of mothers and children
The team drew on data from more than 1,000 mother-child pairs enrolled in long-running studies at the Columbia Center for Children's Environmental Health between 1998 and 2020. Families were recruited from Northern Manhattan and the South Bronx, neighborhoods that have long carried a heavy share of the city's air pollution burden. Researchers tracked each mother's exposure to fine particles known as PM2.5, nitrogen dioxide and polycyclic aromatic hydrocarbons across three successive groups of participants.
Cleaner air, higher scores
Beginning in the late 1990s, New York's air improved after the city and state adopted clean-air and climate policies, from cleaner heating fuels to stricter vehicle rules. As pollution fell, children's test scores rose. Each child was assessed at ages 1, 2 and 3 with the Bayley Scales of Infant and Toddler Development, a standard measure of early mental development. The researchers describe the study as the first to connect declining prenatal exposure to air pollutants, tied to clean-air and climate policy, with improved cognitive development in children.
A policy payoff for the next generation
The findings suggest that cleaning up the air pays off in how children's brains develop, not only in how adults breathe. The authors note that similar benefits could appear in other cities that still carry high pollution loads. They hope the results give policymakers another reason to keep tightening air standards and cutting the emissions that also warm the climate, since the gains show up within a generation.