The US is the third largest contributor to coastal plastics pollution when taking into account its scrap plastics exports and data on illegal dumping and littering, according to a study published in the Science Advances journal. Using plastics waste generation data from 2016 – the latest available in global numbers – scientists from the US Sea Education Association (Woods Hole, Massachusetts; www.sea.edu) together with compatriot partners DSM Environmental Services (Windsor, Vermont; www.dsmenvironmental.com), University of Georgia (Athens, Georgia; www.uga.edu), National Geographic Society (Washington, D.C.; www.nationalgeographic.org) and Ocean Conservancy (Washington, D.C.; www.oceanconservancy.org) calculated that Indonesia was the country with the highest mismanaged plastics waste generated by coastal populations, followed by India, the US, Thailand and China.

In 2016, the US generated the largest amount of plastics waste of any country in the world – 42.0m t, of which between 0.14m and 0.41m was illegally dumped in the US, according to the study, entitled “The United States’ contribution of plastics waste to land and ocean”. More than half of all plastics collected for recycling (1.99m t of 3.91m t collected) in the US were shipped abroad. Of this, more than 88% of exports went to countries with greater than 20% inadequately managed waste, with the vast majority exported to China. Plus, some 15-25% of the plastics scrap exported from the US was estimated to be low value or contaminated, meaning that it was effectively unrecyclable.

Taking these factors into account, the researchers estimated that up to 1m t of US-generated plastics waste ended up polluting the environment beyond its own borders. “For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the US,” said lead author Kara Law, research professor of oceanography at Sea Education Association. “And when you consider how much of our plastics waste isn’t actually recyclable because it is low-value, contaminated or difficult to process, it’s not surprising that a lot of it ends up polluting the environment.”

Using the 2016 data, the researchers estimated that some 2-3% of all plastics waste generated in the US – between 0.91m and 1.25m t – was either littered or illegally dumped into the environment domestically. Combined with waste exports, this means the country contributed up to 2.25m t of plastics into the environment. Of this, up to 1.5m t of plastics ended up in coastal environments (within 50 km of a coastline), where proximity to the shore increases the likelihood of plastics entering the ocean by wind or through waterways. This ranks the US third in the list of countries with the highest mis-managed plastics waste generated by coastal populations in 2016, says the report. Indonesia and India ranked higher because, despite having much lower per capita plastics waste generation, they have much higher proportions of mis-managed waste and they also have larger coastal populations.

“For some time, it has been cheaper for the US to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment,” said Natalie Starr, principal at DSM Environmental Services and a co-author of the study. “We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge.”

Jenna Jambeck, professor at the University of Georgia’s College of Engineering and a co-author of the study, added, “Previous research has provided global values for plastic input into the environment and coastal areas, but detailed analyses like this one are important for individual countries to further assess their contributions. In the case of the US, it is critically important that we examine our own backyard and take responsibility for our global plastic footprint.”

The study noted that although the US accounted for just 4% of the global population in 2016, it generated 17% of all plastics waste. On average, Americans generated nearly twice as much plastics waste per capita as residents of the EU.

Countries with highest plastics waste generated by coastal populations in 2016
Country	Mismanaged plastics waste (in m t)	Income status	Coastal population (millions)	Per capita waste (kg/day)	% of plastics in solid waste	% of mismanaged waste
Indonesia	4.28	LMC	202.49	0.68	14	61
India	3.16	LMC	201.20	0.57	9.5	79
US, upper bound	1.45	HIC	117.94	2.72	13.1	2.98
US, lower bound	0.51	UMC	117.94	2.72	13.1	2.33
Thailand	1.16	UMC	26.73	1.08	17.6	62
China	1.07	UMC	270.94	0.44	9.8	25
The US estimate provides lower and upper bounds reflecting contributions from domestic litter (0.31m t), domestic illegal dumping (0.05 to 0.15m t), and inadequate management of plastics waste generated during the processing of imported US plastics and paper scrap in countries with greater than 20% inadequately managed waste (0.15 to 0.99m t). HIC, high income; UMC, upper middle income; LMC, lower middle income.
Source: SEA