Plastic bag bans work, and now there’s solid science to prove it.
A new nationwide study confirms that plastic bag bans work. In areas that restrict plastic bags through bans or fees, there were 25% to 47% fewer plastic bags found on beaches and shorelines. That’s compared to areas without such policies. The research, published in the journal Science, offers strong evidence that these laws reduce plastic pollution in the environment.
The results come from a detailed analysis of over 45,000 beach and shoreline cleanups across the United States between 2016 and 2023. Researchers found that volunteers collected significantly fewer plastic bags in areas with restrictions, proving that plastic bag bans work in real-world conditions, not just on paper.
Plastic bags are one of the most harmful types of litter in marine environments. They often end up in oceans, where they entangle animals or are mistaken for food. According to scientists, plastic bags kill more sea turtles, whales, dolphins, and porpoises than any other plastic item.
Once in the environment, plastic bags also break down into microplastics. These microplastics have been linked to serious health issues, including hormone disruption, reproductive problems, and increased risks of diseases like diabetes and stroke.
Researchers from the University of Delaware and the Massachusetts Institute of Technology analyzed data from the nonprofit Ocean Conservancy. Since 1986, the organization has hosted volunteer cleanups that track the types and quantities of litter collected. In recent years, volunteers have used a mobile app to record this data, allowing researchers to study trends in plastic pollution over time.
The researchers compared plastic bag litter in ZIP codes with and without laws regulating bag use. They also examined differences between state-level policies and local ones, as well as bans versus taxes. Their main finding: plastic bag bans work, and so do plastic bag fees.
State-level policies had the biggest impact, likely because they cover more people and stores. Some states, like California and Oregon, have full bans on plastic bags. Others, like New Jersey and Vermont, also have similar laws. In contrast, local policies such as those in Alexandria, Virginia, and Howard County, Maryland, had a smaller effect.
The study also explored the differences between types of regulations. Full bans were effective, but even a small fee also helped reduce plastic litter. In some cases, fees appeared even more effective than bans, though the sample size for fee-only policies was small.
What didn’t work well were partial bans. These laws only ban plastic bags below a certain thickness, assuming that thicker bags are reusable or recyclable. But consumers often treat these thicker bags the same way they treat thin ones by throwing them away. In California, for example, a partial ban led to an increase in total plastic bag weight per person between 2014 and 2021. That loophole was only closed last year.
The timing of the study is important. World governments will meet to continue working on a global plastics treaty. This new research could support calls for broader bans and restrictions on harmful plastic products.
Experts say this kind of hard data is essential. “Rather than asking scientists to test every single plastic item separately,” said Oregon State ecotoxicologist Susanne Brander, “we can now apply these findings more broadly.”
Martin Wagner, a professor at the Norwegian University of Science and Technology, agrees. He said the findings prove that real political action can reduce pollution. This is especially valuable since some lawmakers are still unconvinced that plastic bag bans work.
Not all states support these policies. At least 17 states have passed “preemption laws,” which prevent cities or counties from creating their own bag bans. This limits local governments from responding to environmental problems in their communities.
Despite this, environmental groups continue to push for new regulations. Celeste Meiffren-Swango of Environment Oregon co-authored a report that estimated five major bag laws prevented 6 billion plastic bags from being used annually. She says these results show that plastic bag bans work not only for the environment but also for public health.
If you live in a state or city with a plastic bag ban or fee, you’re helping to reduce pollution. Bringing a reusable bag to the store isn’t just about convenience—it’s a small action with a big environmental payoff. By using fewer plastic bags, we keep shorelines cleaner, protect marine life, and limit harmful microplastics in our food and water.
