Study Shows Policies on Plastic Bags Reduce Coastal Pollution
A recent study has found that policies limiting or banning plastic bags have notably decreased plastic waste along the U.S. coastlines.
According to the findings, areas with state and local regulations experienced a decline of between 25% and 47% in the proportion of tiny plastic cleaning bags. This is in stark contrast to locations without such rules. The study was published in Science on Thursday.
Kimberly Olemas, an associate professor of marine science at the University of Delaware, commented on the findings, stating, “There are so many routes that a bag can take from the store’s checkout line.”
Oremus also expressed satisfaction, saying, “It’s great to see a policy that works in such a clear, measurable way.”
Thin plastic shopping bags significantly contribute to coastal plastic pollution. They are seldom recycled effectively and are easily blown away, leading to entanglement and breaking down into harmful microplastics.
As awareness increases, over 100 countries have either instituted bans or fees on plastic bags, the researchers noted.
Olemas, along with lead author and environmental economist Anna Papp, analyzed the effectiveness of these policies across U.S. regions. They examined data from 45,067 coastline cleanups recorded through an app named CleanSwell, part of Clean Conservancy’s Garbage Information and Data for Educational Solutions Database.
The research explored 611 plastic bag policies implemented between 2017 and 2023, assessing how these regulations might reduce plastic waste. They compared the effects of policies at various levels—town, county, and state.
The study revealed a 25% to 47% drop in plastic bag presence in coastal waste. Additionally, there was a reported reduction in the number of entangled animals, decreasing by 30% to 37% in areas with bag regulations, though some results were deemed uncertain.
Stronger impacts were observed for state-level policies compared to town regulations, with fees generally proving more effective than outright bans. However, the researchers acknowledged a need for further analysis to clarify these inconsistencies.
Interestingly, the study also found that bans and fees were most effective in areas where plastic bag pollution was previously less severe.
Papp, who earned her doctorate in Sustainable Development at Columbia University, highlighted, “Overall, our findings show that plastic bag policies are broadly effective at limiting litter along the coastline.” She further added that this data reflects a relative decline when compared to areas without such policies.
The authors emphasized that despite these improvements, plastic contamination is still on the rise. They noted that plastic bag policies can only reduce the impact rather than eliminate the issue entirely.
As the UN Environment Programme prepares for negotiations on a new international plastic treaty this August, the researchers hope for a more holistic approach to tackle the problem.
Olemas remarked, “We’re still seeing increases in plastic bags as a percentage of all cleanup items over time. It doesn’t solve the problem; it just slows its growth.”
