SHANGHAI, China (AP) A northern Chinese province plans to move 64,000 villagers from areas where chemicals in the soil and water are blamed for high levels of heart and bone disease.

Residents of nearly 2,000 villages in the worst- afflicted parts of Shaanxi province are to be moved over the next five years, said provincial health bureau spokesman Li Yanlin.

A third of residents of those villages, scattered throughout the province, suffer from heart disease and physical deformities such as stunted growth, Li said.

Sometimes fatal, the ailments are blamed on a lack of the trace mineral selenium in the soil or on too much fluorine in drinking water, Li said. He said it was cheaper simply to abandon the villages than to bring in safe water and food.

"Resettlement will move people to areas where it is easy to ensure clean water and sanitary housing," he said.

The move underscores China's struggle with so-called endemic diseases caused by too little or too much of certain minerals in the diet.

Such diseases are rare in developed nations because of better nutrition. But they are China's most severe curable health problem, said Wang Zhilun, an expert at Xi'an Medical School in Shaanxi.

"China has the biggest problem with endemic diseases in the world. Nearly 400 million people are affected," he said.

The diseases go back for centuries in China, though it is only in recent decades that a serious effort has been made to eradicate them.

Nationwide, the biggest problem has been iodine deficiency, a leading cause of brain damage in unborn children. China has spent hundreds of millions of dollars to make iodized salt and iodine tablets available to school children and marriage-age women.

In the villages to be relocated, the most common affliction was Kashin-Beck disease, said Li, the health official. That causes a stunting of the bones that can lead to crippling deformities.

Another is Keshan disease, an often fatal heart ailment found mostly in young and middle-aged women.

Both diseases are linked to inadequate consumption of selenium. Studies have also found ties with molds that contaminate rice.

These two diseases affect more than 30 million people in China in a crescent of selenium-poor land stretching from the northeastern province of Heilongjiang to Tibet.

The villages in Shaanxi also suffer from fluorine poisoning, which can cause arthritis and even kidney failure.