Inhaled nanoparticles – human-made specks so minuscule they can’t be seen in conventional microscopes, found in thousands of common products – can cross a natural, protective barrier that normally protects fetuses, according to Rutgers University scientists studying factors that produce low-birth-weight babies. The scientists reported in the medical journal Placenta they were able to track the movement of nanoparticles made of metal titanium dioxide through the bodies of pregnant rats. After the nanoparticles were inhaled into the lungs of the rodents, some of them escaped this initial barrier. From there, the particles flowed through the placentas, which generally filter out foreign substances to protect the fetus. To read the full story.