"Many states and Medicaid rules require blood lead tests for young children, but millions are falling through this safety net, leaving them vulnerable to poisoning – and showing lead worries extend beyond Flint, Michigan".

A new map from the Centers for Disease Control pictures a more limited extent in the U.S. for the Aedes aegypti mosquitos thought to be the main culprit in spreading the Zika virus. Still, it highlights some surprising areas of risk -- like Washington, DC."

Dust and emissions from an Idaho smelter left a legacy of lead poisoning among a generation of children near what is now a Superfund site.

"Sixteen years ago, a presidential task force mapped a plan for the United States to eliminate childhood lead poisoning by 2010. It never happened."

"The wind that blows through Bokoshe, Okla. is an ominous one. A small, low-income town near the Arkansas border, Bokoshe sits in the shadow of a coal power plant. Its toxic byproduct, coal ash, is trucked daily to a nearby dump, and when the wind blows through town, that ash rains down on its residents. They believe it is to blame for the asthma and cancer that runs rampant there."

"It’s no fairy tale — factory farms and air travel form a viral expressway to pandemics."

"A new kind of water contamination has shown up all over the US, including New England. This time it’s not lead, like in the Flint, Michigan water system, but instead it’s a chemical used to manufacture Teflon pans, firefighting foam, even microwave popcorn bags. It’s forced some communities to hand out bottled water and shut down their water systems. Although companies have stopped using this chemical because of health worries, a new replacement compound may be toxic, too."

"People living in areas where the Zika virus is circulating should consider delaying pregnancy to avoid having babies with birth defects, the World Health Organization has concluded."

"Cases of Legionnaires' disease nearly quadrupled in the United States over a 15-year period, and almost all might have been prevented with the proper use of disinfectant, the right water temperature and other measures, federal health officials said Tuesday."

"U.S. EPA has issued its first-ever guidance on contamination in drinking water in the wake of a nuclear disaster, 'dirty bomb' or other radiological accident, drawing criticism from public health and environmental groups."