Plastic Bags: To Ban or Not To Ban

It started with an announcement on the social networking site NextDoor: “Please join us for a meeting with the Director of Zero Waste Management…to discuss how to go about banning plastic grocery bags in Redmond.” Most posts on NextDoor generate a handful of replies. Some popular ones generate twenty. This post unleashed a torrent of discussion: 136 replies from 49 neighbors in my city.

The initial replies simply said, “No thanks” and “Please don’t,” but the discussion soon became much more intense. To my neighbors’ credit, nearly everyone was reasonably polite while expressing their views, some of which were based on facts and some of which were opinions that didn’t necessarily mesh with the facts.

With the flood of information swirling around online, it can be hard to determine what is true. I’ll try to break it down.

Of those who expressed a strong opinion on the idea of a ban on plastic bags, 26 voted no, compared to 6 who supported a ban. Why are people opposed?

·       Practical reasons: they find plastic bags useful.

·       Fear of a nanny state: they believe that the government shouldn’t get involved.

·       They prefer incentives rather than restrictions.

·       No one in our city is throwing plastic bags into the ocean.

Several of my neighbors appreciate having plastic bags available to bag used cat litter or take with them when they walk their dogs. Fair enough – when all the cities near where I used to live in California instituted a plastic bag ban several years ago, I made sure to keep a stash, so I wouldn’t have to buy plastic bags to collect the cat litter. I was already in the habit of taking reusable bags to the grocery store, but I chose to keep the plastic grocery bags I owned rather than dumping them all in the recycling bin.

Plastic bags are handy, but they come with a downside.

Plastic bags are handy, but they come with a downside.

My neighbors, however, made several statements that could use some fact-checking. Which ones are true?

1.       Plastic bags in the ocean are a huge problem

True. But the statistics can be confusing. Despite the image that the term “Pacific Garbage Patch” may suggest, there is no large plastic island in the Pacific Ocean that can be seen from space, or even from an airplane. The Pacific Garbage Patch is, however, real. Much of the trash lies beneath the surface and it ranges from microscopic particles to large pieces of plastic. While plastic debris exists throughout the world’s oceans, currents concentrate it in specific regions, such as the Pacific Gyre.

One of my neighbors mentioned a study saying the density of plastic in the Pacific Gyre is 5.1 kg per square km of ocean surface. I won’t bore you with my calculations (feel free to ask if you are interested), but this suggests that the concentration of plastic near the ocean surface is about 5 parts per billion (ppb) by volume. That means that one billion droplets of water will contain, on average, 5 droplets of plastic.

Expressed this way, the amount of plastic in the ocean seems miniscule. In the U.S., the limits on lead in water are 15 ppb. If less than 15 ppb Pb in water is “safe,” how can 5 ppb of plastic in the ocean be a problem?

My neighbor was talking about a study conducted in 2001. Research in 2014 in the north Pacific near British Columbia showed concentrations ranging from 9 to 9200 particles per cubic meter. Researchers were measuring particles ranging in size from truly microscopic (62 microns) to clearly visible (5000 microns, or 5 mm). If the average particle size is 1 cubic mm, the highest concentration measures around 9 parts per million (ppm). If the average particle is only 0.1 mm in diameter, the concentration drops to 9 ppb.

It is possible to look at the amount of plastic in the oceans in a different way, by comparing it to the amount of fish in the ocean. As of 2016, the oceans contained an estimate of 150 million tons of plastics, a ratio of 1 ton of plastics for every 5 tons of fish, by weight. Assuming a constant stock of fish, without concerted action to slow the flow of plastics accumulation, predictions estimate the weight of plastic will equal the weight of fish by 2050.

A study published in 2017 examined freshwater fish from the Rio de la Plata estuary near Buenos Aires in Argentina and found that guts of 100 percent of the fish contained microplastics. While the concentration of plastic debris in rivers is much greater than in the oceans, it is true that ocean fish and other marine creatures are ingesting plastic. A 2011 review article gives a good overview of the presence of microplastics in the ocean and the consequences of this reality. I don’t have space to discuss the article here, but suffice it to say that the presence of plastics in the ocean is a serious problem.

2.       Most of the plastic in the oceans comes from countries far from the U.S.

True. According to the Ellen MacArthur Foundation, much of plastic leaking into waterways comes from “developing middle-income countries” in Asia. A recent study concluded that between 88 and 95 percent of plastics in the ocean flow there from ten rivers. These include the Yangtze, Indus, and six other rivers in Asia, plus the Nile and Niger rivers in Africa. North America and Europe, regions with sound infrastructure for collecting trash and recycling, contribute a small fraction of the total amount of plastic entering the oceans. Therefore, it seems that addressing the problem in the worst offending rivers would be much more effective than being concerned with plastic trash in Puget Sound.

We, in Redmond, are an even smaller part of the problem, since plastic would have to travel along multiple bodies of water to even reach Puget Sound and eventually the Pacific Ocean. But that doesn’t mean that there is no value to addressing plastic trash locally. Our beloved Pacific Northwest salmon are consuming plastic, albeit not in quantities as high as fish elsewhere in the world. And though my neighbors claim that their used plastic bags all end up in a trash can or recycling center, I’ve seen discarded plastic bags in Redmond.

3.       Plastic bags are more environmentally friendly than paper or reusable grocery bags

Partially true. Calculations of the greenhouse gas (GHG) emissions generated by manufacturing disposable plastic, paper, reusable polypropylene, and reusable cotton bags show that the plastic bag creates the lowest amount of GHG. Those data, however, don’t address how many times a bag is reused. All types of bags can be reused at least once, even though most people only reuse the bags specifically designed for reuse. There is another factor: How many of each type of bag is needed to bag a set amount of groceries? How do 3 paper bags compare to ten plastic bags? What if the baggers double-bag the groceries because they believe the paper bags aren’t strong enough?

4.       Our city is far behind when it comes to banning plastic bags.

True, in a way. The country of Bangladesh banned plastic bags back in 2002. Rwanda and China followed suit in 2008. As of early 2016, 25 countries either ban or tax single-use plastic bags. In the U.S., voters in CA approved a statewide plastic bag ban in November 2016, following bans in multiple cities in the state. Closer to home, the city of Seattle has banned plastic grocery bags since 2012, and 14 other cities in WA have enacted bans. But such bans, while implemented in hundreds of cities across the country, are far from universal throughout the U.S. Attempts to create laws banning plastic bags have failed in many cities. Data on which locations have enacted bans don’t prove whether a ban in Redmond is or isn’t a good idea. Yes, bans reduce the number of plastic bags being used, but financial incentives (imposing a cost for bags or a giving a rebate for bringing reusable bags) may have the same effect.

My conclusion? Banning plastic bags in Redmond would irritate a segment of the population. Given the small sample size on NextDoor, it’s hard to know how accurately the group represents the opinions of residents throughout the city. Are the benefits to banning plastic bags worth the aggravation such a move will cause? I’m not convinced.