A new study finds that regional plastic bag bans in the U.S. significantly reduce coastal plastic bag litter compared with areas without such policies.
Single-use plastic bags are one of the most ubiquitous forms of plastic litter. They are rarely recycled and degrade quickly into microplastics that are often ingested by wildlife, leading to injury, stress and death.
To tackle the problem, many municipalities have turned to regulation. As of 2023, roughly one in three U.S. residents lived in an area with some type of plastic bag policy: Ten states enacted laws to ban plastic bags or charge a fee to discourage their use, another two states enacted such policies in 2024. More than 90% of policies are at the local town level. Meanwhile, more than 100 countries have some type of ban or fee on thin plastic bags.
Despite the widespread adoption of plastic bag policies, there have been limited data on their effectiveness, until now. To fill this gap, study authors Anna Papp, an incoming postdoc at MIT, U.S., and Kimberly Oremus, an associate professor at the University of Delaware’s School of Marine Science and Policy, turned to crowd-sourced beach cleanup data collected between 2016 and 2023 by the nonprofit advocacy group Ocean Conservancy. Through its app called Clean Swell, which records trash picked up by volunteers, the NGO has collected long-term, standardized data from more than 226,000 locations globally.
“The volunteers, when they gather their litter, they count and categorize the items and enter that into the app,” Oremus told Mongabay in a video call.
The researchers then cross-referenced that information with municipal-level plastic bag regulations. They compared areas with outright bans on plastic bags versus those with bag fees. They also compared the size of the areas regulated, ranging from whole states to small towns. Areas with no plastic bag legislation served as controls.
The study found that although each area still had an increase in the number of plastic bags collected, areas with plastic bag policies showed a 25-47% decline in plastic bags as a share of total items collected during the study period, relative to those with no bag policies.
“It’s definitely less bad than without the policies,” Papp said.
The researchers found areas with an outright ban on plastic bags or fees for them were more effective than partial bans allowing thicker bags. They also found that large statewide bans were more effective than smaller ones.
Meanwhile, the study didn’t find any effect of the policies on other plastic items like straws and bottles, Oremus said, meaning the decline in plastic bags specifically was likely due to the bag policy and not another factor.
“This study is further proof that single-use plastic bans are effective,” Melissa Valliant, communications director with Beyond Plastics not part of the study, told Mongabay in an email.
Banner image: of a dolphin with a plastic bag by Jedimentat44 via Flickr (CC by 2.0).
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