In the past, the municipalities would have shipped much of their used paper, plastics and other scrap materials to China for processing. But as part of a broad antipollution campaign, China announced last summer that it no longer wanted to import “foreign garbage.” Since Jan. 1 it has banned imports of various types of plastic and paper, and tightened standards for materials it does accept.

Americans recycle roughly 66 million tons of material each year, according to the most recent figures from the Environmental Protection Agency, about one-third of which is exported. The majority of those exports once went to China, said David Biderman, the executive director of the Solid Waste Association of North America, a research and advocacy group.

But American scrap exports to China fell by about 35 percent in the first two months of this year, after the ban was implemented, said Joseph Pickard, chief economist for the Institute of Scrap Recycling Industries, a trade group.

“It’s a huge concern, because China has just been such a dominant overseas market for us,” Mr. Pickard said.

In particular, exports of scrap plastic to China, valued at more than $300 million in 2015, totaled just $7.6 million in the first quarter of this year, down 90 percent from a year earlier, Mr. Pickard said. Other countries have stepped in to accept more plastics, but total scrap plastic exports are still down by 40 percent this year, he said.

After reading this I'm now acutely conscious of just how much plastic I use day to day. It's rather remarkable--and unsettling.