Others argue that modern economic realities, such as the nation's need to export products at competitive prices, encourage slave-like conditions at the beginning of the production chain. Charcoal ovens, for example, produce fuel for Brazil's steel industry, which exports to the United States.
Vania Aragao, a professor of social services at the Dom Bosco University in Mato Grosso do Sul, said conditions of slavery also are the result of a society that excludes many of its people from education, health care and civic participation. "It is a historical exclusion," she said.
Land has always been concentrated in the hands of a few while millions of landless peasants are left looking for work wherever they can find it. The mechanization of agriculture in parts of Brazil during recent decades has tightened the squeeze on rural workers.
Aragao, who is on a sabbatical to study labor conditions in rural Mato Grosso do Sul, said people who work in conditions of slavery do so because they have no choice. "It is a survival strategy," she said. "If they don't do it, they will die of hunger."
Aragao and Father Prandel, a Catholic priest in the Redemptorist order, are members of a group formed in Mato Grosso do Sul two years ago to combat slave labor. They were out together checking conditions at charcoal ovens on a recent Friday, but they found no one who said he was being forced to work off a debt without payment in cash.
Acionides Rocha, 32, said he has been clearing about $200 for every three months worked since late 1994. Reinaldo Missaia, 35, said payday had been delayed a few days but that he was due to receive $200 in cash for his first 90 days of work after deductions for food and other expenses.
Missaia said he would like to go home to Minas Gerais but probably would stay. "We don't really like it here, but since we're a long way from home, we are obligated to like it," he said as he loaded eucalyptus logs into an oven.
Prandel said his commission, government inspections and publicity have caused oven owners and gatos to take more precautions lately in exploiting cheap labor. "When there was no inspection, the situation was much more visible," he said. "They have learned to camouflage it."
When the commission first began coming to the area, he said, "it was a situation of real slavery. . . . Gatos went around on motorcycles overseeing everything, and they were armed."
In 1994, federal police and labor inspectors raided 400 ovens about four miles from Ribas do Rio Pardo. Prandel said they found many workers in conditions of slavery but that the company that owned the ovens got off with a fine.
Prandel said the commission was peeved. "If Brazil wanted to, if it had the political will, this would be stopped," he said.