Monday, November 18, 2024

Plastic bag bans have lingering impacts, even after repeals

Banning free plastic bags for groceries in Texas resulted in customers purchasing more plastic bags, study finds

University of California - Riverside

Regulations imposed to protect the environment may continue to have impacts even after they are repealed. And those lingering impacts include some that run contrary to the goals of the policies.

Such are te findings of a study published in the Journal of Marketing Research co-authored by UC Riverside marketing professor Hai Che that examined policies to curtail the use of single-use plastic bags in grocery stores and other retail outlets in Austin and Dallas, Texas—policies that were later repealed.

Significantly, the behaviors spurred by the plastic bag rules continued after the rules were no longer in place. And some impacts were not beneficial to the environment.

Che and his coauthors found an increase in sales of plastic bags after the cities prohibited stores from giving away free plastic bags for carrying home groceries. They quantified plastic bag sales by analyzing barcode scanner data on consumer purchases.

“We were hoping for positive spillover effects, like customers will be more environmentally conscious and consume less one-time use plastic or paper products,” said Che, an associate professor at UCR’s School of Business. “But that’s not what happened in the data. People wound up buying more plastic.”

Che added store customer had been repurposing the free grocery bags al as liners for household trash bins.”

The bag rules, however, most likely changed consumer behavior in positive ways as well, such as people getting in the habit of using reusable canvas or burlap bags for everyday shopping, although such data wasn’t available to the researchers, Che said.

The study found that the longer a policy is in place, the longer the behaviors spurred by the policy lingered on.

The Dallas City Council had imposed a 5-cent fee for single-use bags for five months in 2015 before repealing the fee when the city faced lawsuits from plastic bag manufacturers. When free bags became available again, plastic bag sales initially declined sharply and returned to pre-policy levels after 13 months.

The Austin City Council banned single-use carryout bags in 2013, and the policy remained in place for five years until 2018 when the Texas Supreme Court struck down such bans statewide when it ruled on a case about a similar bag ban in Lerado. After the repeal, the carryover effect of plastic bag purchases declined gradually and did not revert to the pre-policy baseline after 18 months, which was the end of the researchers’ analysis time frame. In fact, the carryover effect remained 38.6% above the baseline even at the end of the analysis

To assess the net environmental impact, the research team conducted a “break-even analysis” to determine if the plastic bag policy, despite the negative spillover effects, ultimately reduced plastic waste. They calculated how many fewer single-use grocery bags consumers would need to use to offset the additional trash bags purchased due to the policy. In Dallas, consumers would need to use one less grocery bag every seven trips, while in Austin, it would be one less bag every five trips to break even in terms of environmental impact.

burlap bag
Bans on free plastic bags for groceries are designed to encourage use of reusable canvas or burlap bags which reduce plastic waste in the environment. (Photo by Fiona Goodall/Getty Images)
“Interestingly, even a slight reduction in grocery bag use can offset the increased plastic consumption from trash bags,” Che said. “This suggests that these policies might still benefit the environment overall, even when repealed.”

The study’s title is “Are We Worse Off After Policy Repeals? Evidence from Two Green Policies.” In addition to Che, the authors are Dinesh Puranam of the Marshall School of Business at the University of Southern California, Sungjin Kim of Rutgers Business School at Rutgers University, and Jihoon Hong at W.P. Carey School of Business at Arizona State University.

The study contributes to a growing body of knowledge on the unintended consequences of environmental policies and offers insights applicable beyond plastic bag usage, Che said.

“While our study focused on plastic bags, similar spillover effects have been documented in policies targeting sugary drinks, energy efficiency, and health incentives,” Che said. “In each case, behaviors that weren’t directly targeted by the policy—like purchasing more sugary snacks when soda is taxed—can offset or even undermine the policy’s primary goals.”

Journal

Journal of Marketing Research

DOI

10.1177/00222437241290157

Method of Research

Observational study

Subject of Research

People

Article Title

Are We Worse off after Policy Repeals? Evidence from Two Green Policies

Which EU country is the biggest consumer of lightweight plastic bags?

The number of lightweight plastic bags purchased across the EU is staggering – nearly 30 billion in 2022 alone. However, their usage rate is declining rapidly. Which countries use the most, and which are the most eco-friendly?

EU member states have taken progressive steps over the past decade to reduce the use of lightweight plastic bags, including imposing additional charges or levies and promoting the adoption of compostable and biodegradable alternatives.

Although these measures have not fully resolved the issue, they have proven effective: Today, EU citizens purchase about 30% fewer lightweight plastic bags compared to 2018, according to a Eurostat report published on Tuesday.

However, the overall consumption remains significantly high.

In 2022 alone, nearly 30 billion lightweight plastic bags were bought across the EU, averaging more than 66 bags per person.

Lithuanians buy nearly a bag a day, Belgians almost none in a year

Lithuania recorded the highest use per capita, with 249, followed by Latvia (193) and the Czech Republic (185).

With only four bags per capita, Belgium reported the lowest consumption rate, followed by Poland (7) and Portugal (13).

What are lightweight plastic bags, and what impact do they have?

Lightweight plastic bags are less than 50 microns thick and are normally used for carrying small amounts of groceries.

They have a devastating impact on the environment.

Not only do they take centuries to decompose, but they also break up into microplastics, ending up in the human and animal food chain.

Study finds 'safe' BPA alternatives pose health risks

A virtual simulation of the interaction between complex biological membranes and alternative bisphenols suggests that BPF and BPS also accumulate in biological membranes.

Universidad Miguel Hernandez de Elche

Comparisson of bisphenol molecules — image:
Bisphenols are a group of endocrine-disrupting chemicals used worldwide for the production of plastics and resins. Bisphenol A (BPA), the main bisphenol, exhibits many unwanted effects. BPA has, currently, been replaced with bisphenol F (BPF) and bisphenol S (BPS) in many applications in the hope that these molecules have a lesser effect on metabolism than BPA. After conducting molecular dynamics simulations to compare the localization and interactions of BPA, BPF, and BPS in a complex membrane, the ata support that both BPF and BPS, behaving in the same way in the membrane as BPA and with the same capacity to accumulate in the biological membrane, are not safe alternatives to BPA.
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Credit: Villalaín, J. IDiBE UMH

A study by Professor José Villalaín of the Miguel Hernández University of Elche (UMH) in Spain, published in the Journal of Xenobiotics, reveals that bisphenol analogs BPF and BPS, used as safer alternatives to BPA, may still pose health risks. Using high-resolution computer simulations, the research shows these compounds accumulate in complex biological membranes, potentially disrupting endocrine function and causing diseases like obesity and diabetes.

While European health authorities have warned about the adverse effects of bisphenol A in plastic production and have imposed legal restrictions on its use, similar compounds used in the plastics industry are suspected of causing the same health issues. This new study adds to the growing body of scientific evidence pointing to the dangers of these compounds.

Using computer simulations, the expert from the UMH’s Institute of Research, Development, and Innovation in Healthcare Biotechnology analyzed the interactions between human cell membranes and the molecules of bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS). BPF and BPS are being marketed as safer alternatives. The results show that these compounds are so similar to bisphenol A that they accumulate in cells and affect membrane lipids, making them potentially harmful and capable of causing diseases.

Some synthetic and natural chemical compounds can interfere with the normal functioning of the endocrine system, which regulates many vital functions. These substances are known as “endocrine disruptors.” These chemicals are present in everyday items, including plastic bottles, food containers, metal coatings, detergents, flame retardants, foods, toys, cosmetics, and pesticides. Some, such as DDT, have already been banned. Others are under ongoing review, with increasing regulation, as is the case with bisphenol A, which has been identified by the European Food Safety Authority (EFSA) as a “health concern for consumers across all age groups.”

Bisphenols are endocrine disruptors used globally in the production of plastics and resins. Bisphenol A, the most common bisphenol, has been linked to numerous adverse health effects in both humans and animals. As a result, BPA is being replaced with Bisphenol F (BPF) and Bisphenol S (BPS) in the hope that these compounds will have less of an impact on metabolism.

However, studies conducted over the past decade have found elevated concentrations of these BPA analogs in urine samples from European adults. At the same time, BPS and BPF have been associated with an increased risk of cardiovascular disease, cancer, and other health problems. The scientific community is still investigating the full extent of the risks posed by these supposedly ‘safe’ bisphenols.

To better understand these compounds, Professor Villalaín conducted virtual simulations to compare how BPA, BPF, and BPS interact with cell membranes — the layers that separate cells from their surrounding environment. The technique, known as molecular dynamics, allows the creation of complex biomembranes that closely resemble those found in human cells.

The UMH study shows that bisphenols tend to accumulate at the membrane's interface without a preferred orientation and may exist in either monomeric or aggregated states. They also affect the biophysical properties of the membrane's lipid components. The properties of bisphenols can be partially attributed to their membrane-affecting behavior and their ability to alter the membrane’s physical characteristics.

These findings suggest that BPF and BPS, which behave similarly to BPA in the membrane and share its ability to accumulate in biological membranes, are not safer alternatives to BPA. "Given the environmental and health importance of these molecules, the use of these bisphenols should be discontinued due to the risks they may pose to human and animal health," concludes the expert.

The study, published in one of the leading journals in this field, supports the growing scientific evidence that BPF and BPS also act as endocrine disruptors in the human body. “Since bisphenols tend to accumulate in the lipid phase [the part of the cell membrane where molecules responsible for transporting substances and chemical signals into and out of cells are located], the concentration of bisphenols found in biological membranes can be significant,” says Professor Villalaín. Bisphenols interfere with the chemical messages within the cell by adhering to it, which leads to negative health effects, including diabetes, obesity, and infertility.