Ambient air pollution and risk of congenital anomalies: a systematic review and meta-analysis.

Summary: Breathing dirty air isn't just bad for your lungs; it might affect the tiniest hearts before they are even born. A comprehensive review of ten major studies has found a concerning link between common air pollutants—specifically nitrogen dioxide from traffic and sulfur dioxide from industry—and specific heart defects in newborns.

Researchers discovered that exposure to these gases increased the risk of conditions like "Tetralogy of Fallot" and narrowing of the aorta. Additionally, particulate matter (tiny dust and soot particles) was linked to holes in the wall separating the heart's upper chambers. While the study didn't find links to all types of birth defects, such as cleft palates, it highlights a significant reason for expecting mothers to limit exposure to heavy pollution where possible.