Fears of widespread domestic pollution were amplified by “Plastic China,” a recent documentary film about a bleak town in the eastern province of Shandong where people earn their living by picking through scrap plastics and processing them in machines that belch black smoke. The film went viral in mainland China in January before disappearing from the internet there.

Pollution in the industry is “not only China’s problem,” said Wang Jiuliang, the film’s director.

“It’s the world’s common challenge,” he said.

China’s regulatory fight against imported garbage began in 2013, when a flurry of port inspections forced overseas recyclers to clean up their operations and invest in new waste-sorting technologies.

In July, China raised the stakes by telling the World Trade Organization that it would ban 24 kinds of imported waste, including some types of paper and plastics, by the end of the year. Chinese regulators also began restricting wastepaper imports.