Chinese businessmen opened a new magnesium smelter in Hunan province early this month. They hadn't bothered to get a license. As soon as they fired it up, the plant began spewing emissions heavily laced with lead, which quickly drifted down to a kindergarten and elementary school about one-quarter mile away.

A few days ago, the state shut down the smelter. More than 1,300 children were affected; dozens of them were hospitalized. But once lead finds its way into a child's blood system, there's not a lot medicine can do. Lead lodges in a child's the brain and cripples intellectual development. Parents were furious.

But I wonder how many of them know of a far more common threat to their children's intellectual development, one that cripples mental development in hundreds of millions of kids all over the world.

It's called stunting, an insidious, slow-moving condition that robs children of their ability to thrive, either physically or mentally. While 1,354 Chinese children suffered lead exposure, 53 million Chinese children under 14 years of age are growing up stunted. As UNICEF puts it, "deprivations in feeding and care that impair growth in the critical first years may reduce a child's cognitive development and learning ability, often leading to poor school performance and dropping out. Once established, stunting and its effects typically become permanent."

Within the developing world, China's stunting rate, 20 percent of its children, is fairly low. It has fallen by one-third in the last decade — quite an achievement. In neighboring North Korea, the rate is 62 percent. Two-thirds of the children, more than 1 million, are stunted — one of the highest rates in the world.

Was it an issue in the Afghan presidential campaign? Half of Afghanistan's children are stunted. Honduras is locked in argument about the coup that expelled the duly elected president; 40 percent of Honduras' children are stunted. How about Pakistan, where the government is expending much of its energy trying to balance demands from Washington against incursions by their traditional ally, the Taliban. Fifty percent of Pakistan's children are stunted.

By comparison, 2 percent of American children are stunted — still shameful. In Switzerland the rate is close to zero.

Stunting is typically a byproduct of poverty. Families are unable to provide their children the nutrition they need to grow, at least 2,100 calories a day, and a balanced diet. But poverty is not the only cause. Ignorance and neglect are others — both often the products of a low IQ, which itself is often the product of stunting. UNICEF says: "Stunting also occurs when babies are born underweight because the mother was poorly nourished or because she was herself stunted."

All told, the agency says, one-third of the children under 5 who live in the developing world are stunted.

Solving the problem is a major undertaking. The United Nations is the only agency that is attacking it worldwide. In dozens of poor states, the U.N.'s World Food Program delivers high-calorie meals to school children. But the program can afford to feed only a small percentage of the students, and in most places the government is unwilling to pick up the rest. Many of these leaders would rather spend their money on advanced weaponry for their armies, development of cities for the well-off people live who live there — anything but the unseen millions of poor people who live in the countryside.

What can the United States do? The State Department each year publishes heavily researched reports on human rights, drug trafficking, religious freedom and human trafficking. All of these are important topics.

Why not a new report, on human nutrition, with appropriate penalties for the nations that neglect their children?

Joel Brinkley is a former Pulitzer Prize-winning foreign correspondent for The New York Times and a professor at Stanford University. Reach him at: brinkley@foreign-matters.com