Antamina is the world's third-largest zinc and eighth-largest copper mine, according to Xstrata, which along with BHP Billiton, the world's largest mining company, holds a 33.75 percent stake. It produced 334,000 tons of copper last year and 235,000 tons of zinc. Independent economist Epifanio Baca of the DESCO think tank said it earned more than $1.5 billion. Consortium partners BHP Billiton Ltd. is based in Australia, Xstrata in Switzerland, Teck-Cominco Ltd. in Canada and Mitsubishi Corp. in Japan.

Environment Minister Manuel Pulgar had demanded the company be made to pay the maximum fine permitted under law, or $13.7 million, for negligence. His deputy, Mariano Castro, told The Associated Press his agency's investigation is not over. He declined to say whether more serious sanctions could be ordered. A 2009 law permits egregious violators to be suspended or even shut down.

Antamina has not yet explained what caused the leak or why it took two hours to halt the slurry flow. Company officials did not respond to repeated telephone and emailed requests for comment, and refused to talk to reporters at the town meeting.

An Antamina document obtained by the La Republica newspaper describes some of slurry's ingredients as "highly toxic" and says they include lead and arsenic, which are poisons. Castro said a government analysis of the slurry could be ready as early as next week.

The government occupational health agency, CENSOPAS, took blood and urine samples from 52 villagers a week after the spill and six of the 18 children tested had unacceptably high levels of copper while one had dangerously high levels of lead. The U.S. Agency for Toxic Substances and Disease Registry says children are especially susceptible to damage from high levels of copper, which can cause liver damage but has not been shown to be carcinogenic.

CENSOPAS only tested for copper, lead and arsenic. And it did not name the villagers tested. Mayor Felipe Lazaro, who provided the AP with the report, said he asked CENSOPAS for their identities but the agency refused.

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