By KEITH BRADSHER
GUYUN VILLAGE, China


SOME OF THE greenest technologies of the age, from electric cars to efficient light bulbs to very large wind turbines, are made possible by an unusual group of elements called rare earths. The world’s dependence on these substances is rising fast.

Just one problem: These elements come almost entirely from China, from some of the most environmentally damaging mines in the country, in an industry dominated by criminal gangs.

Western capitals have suddenly grown worried over China’s near monopoly, which gives it a potential stranglehold on technologies of the future. In Washington, Congress is fretting about the United States military’s dependence on Chinese rare earths, and has just ordered a study of potential alternatives.

Here in Guyun Village, a small community in southeastern China fringed by lush bamboo groves and banana trees, the environmental damage can be seen in the red-brown scars of barren clay that run down narrow valleys and the dead lands below, where emerald rice fields once grew.

Miners scrape off the topsoil and shovel golden-flecked clay into dirt pits, using acids to extract the rare earths. The acids ultimately wash into streams and rivers, destroying rice paddies and fish farms and tainting water supplies.

On a recent rainy afternoon, Zeng Guohui, a 41-year-old laborer, walked to an abandoned mine where he used to shovel ore, and pointed out still-barren expanses of dirt and mud. The mine exhausted the local deposit of heavy rare earths in three years, but a decade after the mine closed, no one has tried to revive the downstream rice fields.

Small mines producing heavy rare earths like dysprosium and terbium still operate on nearby hills. “There are constant protests because it damages the farmland - people are always demanding compensation,” Mr. Zeng said.

“In many places, the mining is abused,” said Wang Caifeng, the top rare-earths industry regulator at the Ministry of Industry and Information Technology in China.

“This has caused great harm to the ecology and environment.”

There are 17 rare-earth elements - some of which, despite the name, are not particularly rare - but two heavy rare earths, dysprosium and terbium, are in especially short supply, mainly because they have emerged as the miracle ingredients of green energy products. Tiny quantities of dysprosium can make magnets in electric motors lighter by 90 percent, while terbium can help cut the electricity usage of lights by 80 percent. Dysprosium prices have climbed nearly sevenfold since 2003. Terbium prices quadrupled from 2003 to 2008.

China mines more than 99 percent of the world’s dysprosium and terbium. Most of China’s production comes from about 200 mines here in northern Guangdong and in neighboring Jiangxi Province. China is also the world’s dominant producer of lighter rare earth elements, valuable to a wide range of indus tries. But these are in less short supply, and the mining is more regulated.

Half the heavy rare earth mines have licenses and the other half are illegal, industry executives said. But even the legal mines, like the one where Mr. Zeng worked, often pose environmental hazards.

A close-knit group of mainland Chinese gangs with a capacity for murder dominates much of the mining and has ties to local officials, said Stephen G. Vickers, the former head of criminal intelligence for the Hong Kong police who is now the chief executive of International Risk, a global security company.

The Ministry of Industry and Information Technology issued a draft plan last April to halt all exports of heavy rare earths, partly on environmental grounds and partly to force other countries to buy manufactured products from China. When the plan was reported on September 1, Western governments and companies strongly objected and Ms. Wang announced on September 3 that China would not halt exports and would revise its overall plan. But the ministry subsequently cut the annual export quota for all rare earths by 12 percent .

The United States Congress responded by ordering the Defense Department to conduct a comprehensive review, by April 1, of the American military’s dependence on imported rare earths for devices like night-vision gear and rangefinders.

Western users of heavy rare earths say that they have no way of figuring out what proportion of the minerals they buy from China comes from responsibly operated mines.

Multinational corporations are starting to review their dependence on heavy rare earths. Toyota said that it bought auto parts that include rare earths, but did not participate in the purchases of materials by its suppliers.

Osram, a large lighting manufacturer that is part of Siemens of Germany, said it used the lowest feasible amount of rare earths.

The biggest user of heavy rare earths in the years ahead could be large wind turbines, which need much lighter magnets for the five-ton generators at the top of ever-taller towers. Vestas, a Danish company that has become the world’s biggest wind turbine manufacturer, said that prototypes for its next generation used dysprosium, and that the company was studying the supply.

Executives in the $1.3 billion rareearths mining industry say that less environmentally damaging mining is needed, given the importance of their product for green energy technologies. Developers hope to open mines in Canada, South Africa and Australia, but all are years from large-scale production and will produce sizable quantities of light rare earths.

Their output of heavy rare earths will most likely be snapped up to meet rising demand from the wind turbine industry.

“This industry wants to save the world,” said Nicholas Curtis, the executive chairman of the Lynas Corporation of Australia . “We can’t do it and leave a product that is glowing in the dark somewhere else, killing people.”


This mine in Guyun Village exhausted its heavy rare-earth elements in three years. The elements are in high demand around the world. / THOMAS LEE FOR THE NEW YORK TIMES

In Rare Earth Metals, Chinese Dominance China has a near monopoly on this group of 17 elements, some of which are used to make efficient light bulbs, electric car motors and wind turbines. And in recent years, the price of one of them, dysprosium, has soared.