Why a plastic bag ban could lead to unintended environmental consequences

“We should be really cautious about just switching from one single-use lifestyle to another.”

In making the announcement about the ban, which is slated to come into effect by the end of next year, Environment Minister Jonathan Wilkinson said that local stores would provide customers with alternatives, like paper bags or reusable bags.

Like plastic, paper bags are single use

The problem with something like a paper bag alternative, however, is that it’s also single use, and its production leaves a carbon footprint that is greater than that of the manufacturing of disposable plastic grocery bags, experts say.

The process of producing paper bags includes the environmental impact on forests and land use, as well as the use of machinery to cut down trees. The pulping process inside pulp and paper mills also produces pollution, and since paper bags are thicker than the disposable plastic bags, they require more energy to manufacture.

In 2011, a research paper produced by the Northern Ireland Assembly found that it “takes more than four times as much energy to manufacture a paper bag as it does to manufacture a plastic bag,” the BBC reported.

“Paper does have an environmental footprint, and then even making millions of paper bags and transporting them costs more in terms of transportation costs and greenhouse gases than it would for the equivalent number of plastic bags,” Walker said.

Rebecca Taylor, an assistant professor at the University of Sydney School of Economics in Australia, conducted a study looking into the ban on plastic grocery bags in California.

Her research found that the ban reduced plastic carryout bag usage by 18.1 million kilograms per year. However, the ban also led to an increase in the use of paper bags, rising by 652 million additional paper bags, weighing 37.5 million kilograms a year — more than double the weight of the banned plastic bags.

While plastic grocery bags are considered single use, many customers actually reuse them for garbage disposal in their homes, dog poop cleanup and storage receptacles, Taylor said.

A 2017 study conducted by Recyc-Québec, a Quebec recycling group, found that the reuse for such bags was more than 77 per cent. The study also found that because the conventional plastic grocery bag is thin and light, its production generates the least environment impact, compared with other disposable bags, including paper bags.

Meanwhile, Taylor’s study found that the California grocery bag ban led to a 5.4-million-kilogram annual increase in sales of store trash bags, which are thicker than plastic grocery bags. More specifically, the study found that store-bought plastic bags increased the sales of small, medium and large trash bags by 120 per cent, 64 per cent and six per cent, respectively.

“But that’s assuming that all Canadians are going to do that,” Walker said. “I guess in an ideal world, we will learn and quickly adapt to life without plastics.“

Garbage bins don’t need bags

When it comes to garbage and bin liners, Walker said that in theory, people can actually put their garbage in a regular, sturdy, hard plastic bin and then rinse it out occasionally.

As for the environmental impact of paper bags, Walker said studies like Taylor’s omit a very important fact: They do not look at the after-use or the end-of-life impacts of paper versus plastic. 

Plastic will stay in the environment for hundreds of years, he said, and during that time will break down to microplastics.

“And we all know that microplastics are bad news, and we don’t even know yet how harmful it is to the ecosystem or ourselves,” Walker said.

Paper, meanwhile, does break down, can be recycled, and if soiled with some organics, it can be put into compost, he said. 

“But either way, we can deal with it,” Walker said.

“What we need as Canadians is behavioural change, and that behavioural change will come about by, you know, adoption of using reusable bags.”

But those bags may come with their own problems and potential health risks.

For example, a 2011 study by the British government found that a cotton tote bag would have to be used 131 times before it was better for the environment than the single use of a plastic grocery bag.

Reusable bags are potential bacteria carriers

And Ryan Sinclair, an associate professor at Loma Linda University School of Public Health in California, found in studies that reusable grocery bags have the potential of carrying bacteria and viruses, including norovirus and coronavirus.

“So it potentially could bring things from your private residence into the store, and then it potentially could bring things from the store back to your home,” Sinclair told CBC News.

While the clothes you wear may also have that potential, reusable bags touch surfaces in grocery stores that lots of other people touch, including carts and, more importantly, the checkout counter, he said.

WATCH | Liberal government announces ban on single-use plastics:

Environment Minister Jonathan Wilkinson lists six single-use plastics to be banned in Canada beginning 2021. 1:04

“That’s where any kind of public health hazard would kind of amplify, because that’s places where everybody touches,” Sinclair said. “People spread out throughout all the different aisles but then all come back to one place, which is the checkout counter.”

Another problem with these reusable bags is that few people wash them, he said.

“If you’re going to use them, you should definitely wash them,” Sinclair said. 

That means people should probably avoid polypropylene bags and get cotton, burlap or nylon bags, and wash them at a higher temperature and use some kind of disinfectant, he said.