Maria Texeira-Gomes holds a photo of her 5-year-old son, Matheo, who has struggled with asthma nearly all his life. Richard Knox/NPR hide caption

itoggle caption Richard Knox/NPR

Surplus and expired drugs collected during the DEA's fourth National Prescription Drug Take-Back Day. New research suggests it might be better for the environment to dispose of drugs in household trash. Keith Srakocic/AP hide caption

itoggle caption Keith Srakocic/AP

Even in the remote Faroe Islands, some children have high levels of perfluorinated compounds in their blood. The chemicals may interfere with the immune system. Stig Nygaard/Flickr hide caption

itoggle caption Stig Nygaard/Flickr