UNICEF

How many children in the world have been exposed to dangerous levels of lead?

That's a pressing question that has had no definitive answer until now. About 1 in 3 children have been exposed to lead at levels shown to damage their health and cognitive development, according to a groundbreaking report that is the first to document the problem globally.

For years, Caribbean governments have argued their countries bear the brunt of climate change. A new U.N. study says Caribbean children may bear the worst of it.

After decades of progress against one of the most contagious human viruses, the world is seeing measles stage a slow, steady comeback.

The World Health Organization and the CDC say in a new report that there were nearly 10 million cases of measles last year, with outbreaks on every continent.

An estimated 140,000 people died from measles in 2018, WHO says, up from an all-time low of 90,000 in 2016.

And so far 2019 has been even worse.

Go to the hospital or a clinic in a wealthy country, and you take it for granted that there's going to be enough clean water — for the doctor to wash her hands before she attends to you, for the staff to clean the floors and linens, and for you to drink when you get thirsty.

But in 17 countries at least one in five health-care facilities has no clean water service on site.