The global plastic waste trade contributes to coastal litter in importing countries, study shows

(Press-News.org) URBANA, Ill. – The ubiquitous plastic beverage bottle makes up about half of plastic waste collected for recycling in the U.S. Most recycled plastic is processed domestically, but a portion is traded overseas. A new study from the University of Illinois Urbana-Champaign draws on citizen science data to investigate how the global plastic waste trade contributes to litter along coastlines and waterways in importing countries.

“There has been a lot of news coverage about the plastic waste trade. The concern is that exporting waste to another country creates opportunities for that waste to escape into the environment during transportation and storage. We wanted to see if plastic waste imports lead to higher amounts of plastic litter found in coastal areas,” said Becca Taylor, assistant professor in the Department of Agricultural and Consumer Economics, part of the College of Agricultural, Consumer and Environmental Sciences at U. of I. 

Plastic waste is an internationally traded commodity, which can be recycled into reusable materials, whereas plastic litter is the pollution that results from untreated waste.

“Overall, we find that a 10% increase in the amount of plastic waste a country imports is associated with a 0.6% increase in the amount of littered plastic bottles collected from coastal areas,” she said. 

This may not sound like much but it adds up quickly. While only about 2% of plastic waste is traded globally, it is a substantial amount considering the huge growth in plastic production over the past 30 years. International trade of plastic waste reached its peak in 2014 with 16 million metric tons (about 35 billion pounds). Furthermore, the waste trade moves primarily from the global North to the global South, leading to concerns about “pollution havens,” where countries with low environmental regulations and inefficient waste management systems are more likely to attract polluting industries.

To study their question, the researchers turned to an unconventional source: citizen science — that is, data collected by ordinary people around the world.

The Ocean Conservancy, a non-government environmental advocacy organization, leads an annual global beach clean-up event. Volunteers are trained to collect and document all coastal litter in designated areas. The data are aggregated to the country level and made publicly available.

Taylor and her colleagues obtained data for 90 countries from 2003 to 2022. They focused on plastic bottles because they are a recycled commodity, unlike other common types of waste such as cigarette butts and food wrappers.

The researchers used the United Nations global trade database to measure plastic waste imports per country and year. They also drew on existing academic research to evaluate plastic waste mismanagement rates by country.  The authors find that a doubling of the amount of plastic waste a country imports is associated with a 6% increase in the number of littered bottles collected. Furthermore, countries that struggled with poor waste management systems had a proportionally higher increase in litter.

The authors also examine recent changes in the international waste trade, which shifted considerably in 2017, when China banned plastic waste imports. China had been the primary market for plastic waste, and its policy change caused total plastic imports to decrease by 73%. 

Some of the waste found its way to other countries, such as Thailand and Malaysia, where plastic imports increased significantly after China’s ban. The researchers looked at what happened to litter in those countries, finding that a 1000-ton increase in plastic waste imports from 2016 to 2017 was associated with a 0.7% increase in littered plastic bottles. 

However, countries that initially saw an increase in their plastic imports after China's policy changed later implemented their own waste import bans. Another policy change came in 2019 when plastic was added to the Basel Convention, a global agreement on the trade of hazardous waste. Consequently, countries that have ratified the convention (the U.S. is not among them) agree to follow certain guidelines for trade.

“In summary, we do find that plastic waste imports lead to increased coastal litter, and policies that aim to regulate or ensure importing industries are following best practices will have an impact. But cutting down on trade is not sufficient to eliminate litter along the coastlines. We also need to consider waste management practices more broadly and provide assistance to countries with less advanced waste management systems,” Taylor concluded. 

The paper, “Plastic waste imports & coastal litter: Evidence from citizen science data,” is published in Ecological Economics [10.1016/j.ecolecon.2025.108848]. 

Research in the College of ACES is made possible in part by Hatch funding from USDA’s National Institute of Food and Agriculture.

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