"Biodegradable Plastic Bags, Not So Biodegradable"
by Vicky Stein
The average person uses a typical plastic bag for as short a time as 12 minutes before throwing it away, never thinking of where it may end up.
Yet once consigned to a landfill, that standard grocery store tote takes hundreds or thousands of years to break down — much more than a human lifetime. Bags make up an alarming amount of the plastic found in whale stomachs or bird nests, and it’s no wonder — globally, we use between 1 and 5 trillion plastic bags each year.Biodegradable plastic bags are marketed as more eco-friendly solutions, able to break down into harmless material more quickly than traditional plastics. One company claims their shopping bag “will degrade and biodegrade in a continuous, irreversible and unstoppable process” if it ends up as litter in the environment.
In a study published this week in Environmental Science and Technology, researchers put supposedly eco-friendly bags made from various organic and plastic materials and sourced from U.K. stores to the test. After three years buried in garden soil, submerged in ocean water, exposed to open light aIn fact, the biodegradable bags that had been left underwater in a marina could still hold a full load of groceries.
“What is the role of some of these really innovative and novel polymers?” asked Richard Thompson, a marine biologist from the University of Plymouth and the study’s senior author. A polymer is a repeating chain of chemicals that makes up a plastic’s structure, whether biodegradable or synthetic.
“They’re challenging to recycle and are very slow to degrade if they become litter in the environment,” Thompson said, suggesting these biodegradable plastics may be causing more problems than they solve.nd air or stashed in a laboratory, none of the bags broke down completely in all the environments.What the scientists found
Even in a tough marine environment, where algae and animals quickly covered the plastic, three years wasn’t long enough to break down any of the plastics except for the plant-based compostable option, which did disappear underwater within three months. The plant-derived bags, however, remained intact but weakened when buried under garden soil for 27 months.
The only treatment that consistently broke down all of the bags was exposure to open air for more than nine months, and in that case even the standard, traditional polyethylene bag disintegrated into pieces before 18 months had passed.
“I would take that timescale to be too long for these products to be regarded as providing an environmental advantage,” Thompson said.Even if these bags take less time to break down than traditional plastic bags, as litter they would still have enough time to become potentially deadly food for ocean animals like seabirds, whales, turtles or fish. Moreover, they would still be an eyesore and take up space at waste facilities for months or years.
And when some of the plastic bags did seem to break down, such as the bags left to the open air, it was unclear if the disintegration was complete.
“Did the plastic that was lost just become smaller pieces of plastic?” Kalow asked, “Or did it become molecules that could dissolve in water and be consumed?”Future studies, she said, should dig into the fate of those disintegrated plastic particles, to ascertain whether they truly break down and disappear — or become microplastics and harmful chemicals.
Why it matters
Even standard plastic bags can’t be recycled from your home recycling bin, so most end up in landfill or are swept away by water or wind, becoming litter.
Biodegradable and compostable bags are meant to solve these problems, but the study indicates that’s not the case so far.
These alternative bags aren’t meant to end up as litter in the street or in the natural environment — ideally, they’d all be treated just as manufacturers expect. Biodegradable bags would be landfilled or, in some cases, recycled into new plastics — at least in theory.But “even if we can make something that’s recyclable, that doesn’t mean any commercial recycling plant would be interested in dealing with it,” Kalow said. Biodegradable plastics can’t generally be recycled with other plastics — in fact, they can ruin other batches of recyclable plastic, degrading the product until it becomes unusable.
Meanwhile, the eco-conscious should hope their compostable bags end up in industrial composting facilities where high temperatures and favorable conditions for bacteria and other living things would break them down. (Compostable bags in chilly, oxygen-starved landfills can actually be preserved rather than destroyed.
These are the real problems, Thompson said. Labels like “biodegradable,” “compostable” or even “recyclable” are theoretical — they don’t reflect the reality of what happens to the materials we throw away or litter into the oceans, and they don’t help people accurately understand how to get rid of them.Three years after the researchers’ plastic bags were buried or submerged, they were nearly as useful — and as harmful — as the day they were made.
Some simple solutions might help. Thompson suggested that standardized products, made of the same sets of materials, could streamline our waste management systems and allow much more of our waste to be profitably recycled. Kalow, the polymer chemist, said there may yet be hope for new, improved biodegradable plastics if only we could discover that technology.
In the meantime, it doesn’t hurt to remember your reusable bag on your way to the store.
Which section provides the most evidence supporting the need for new, improved biodegradable plastics?
(1 point)
Responses
“How biodegradable plastic bags don’t live up to their name”
“How biodegradable plastic bags don’t live up to their name”
“What the scientists found”
“What the scientists found”
“What the researchers did”
“What the researchers did”
“Why it matters”
3 answers
The section that provides the most evidence supporting the need for new, improved biodegradable plastics is “What the scientists found.”
This section details the findings of the study, highlighting that despite being marketed as biodegradable, many of the tested bags did not break down effectively in various environmental conditions over a three-year period. It emphasizes that even plant-based compostable bags took time to degrade and raises concerns about whether the disintegration was complete or resulted in harmful microplastics. This evidence illustrates the shortcomings of current biodegradable plastics and underscores the need for improved alternatives.
3. In broadcast newsrooms, women make up 31 percent of news directors and 20 percent of general managers, according to a 2014 survey by the Radio Television Digital News Association. The fewest female leaders appear in radio, where they account for 23 percent of news directors and 18 percent of general managers.
4.The trend is not limited to the U.S., or even to media. A survey of 500 media companies in nearly 60 countries discovered that men hold 73 percent of management positions. And among Fortune 500 CEOs, women account for 4.8 percent.
What would happen if you reversed the order of paragraphs 3 and 4?
(1 point)
Responses
The broader implications of an idea would be discussed before the reader understands what the idea is.
The broader implications of an idea would be discussed before the reader understands what the idea is.
The focus of the article would shift from old statistics to trends in the industry.
The focus of the article would shift from old statistics to trends in the industry.
The importance of the problem would become clearer because the worldwide impact would be centered sooner.
The importance of the problem would become clearer because the worldwide impact would be centered sooner.
The extent of the problem would be lost on readers because they would not receive all the data.
If you reversed the order of paragraphs 3 and 4, the importance of the problem would become clearer because the worldwide impact would be centered sooner.
By discussing the broader context of gender disparities in leadership positions on a global scale first, readers would immediately grasp the significance and prevalence of the issue beyond just the statistics from U.S. broadcast newsrooms. This would set the stage for the specific data about news directors and general managers, emphasizing that these numbers are part of a larger trend.
