Not until Perry Gottesfeld pulled up to the front gates of Seigneurie in Cameroon did he realize the African country’s leading paint manufacturer was owned by a U.S.-based corporation.

“A big sign read PPG,” Gottesfeld, executive director of the nonprofit Occupational Knowledge International, recalled from his March 2011 visit to the factory. “We were shocked.”

The reason for the surprise: His research team had just discovered that more than 40 percent of Seigneurie house paints on the market in Cameroon contained high levels of lead, with the neurotoxic heavy metal accounting for up to half the weight of some paints. House paint containing lead — added as an inexpensive way to brighten color, speed drying and prevent corrosion — was banned in the U.S. more than three decades ago.

“That is more or less the way we do things,” said David Rosner, co-director of the Center for the History and Ethics of Public Health at Columbia University. “We end up exporting our poisons and try to make every last bit of profit we can.”

The global spread of toxic lead paint follows an unfortunate pattern that covers everything from leaded gasoline to unsafe medications, according to Rosner and other public safety experts. Long after a product has been pulled from U.S. shelves, it still tends to appear in open markets elsewhere — often in developing countries where few regulations protect public health.

Asbestos is another case in point. As the U.S. stopped most traditional uses of the microscopic mineral fibers due to their toxicity, companies continued to ship the substance elsewhere. In 2011, according to the United States Geological Survey, the U.S. exported about $27 million worth of asbestos products.

“It’s every sort of toxic chemical you can think of,” said Evan Mascagni, a producer of an upcoming documentary that highlights the global sale of pesticides banned in the U.S. and the health dangers those chemicals pose to unsuspecting farmers, agricultural workers and children.

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