Particles of black carbon have been found inside the placenta, raising questions of health risks to fetuses. (Credit: Africa Studio/Shutterstock)

Many of us don’t give much thought to the air we breathe. But if you live in a city, near a major road, next to an industrial plant or even just have a wood burning stove, that air is often laced with miniscule pollutants. After we inhale, those particles can lodge in our lungs and travel throughout the body. For pregnant women, this may put their