How Do Plastic Bags Affect Our Environment?

plastic bag

Whether you live in an urban megacity or rural farmland, you surely see plastic bags blowing around anytime you leave the house.

Some blow across roads like post-apocalyptic tumbleweed, while others become snagged in the branches of street trees. Still others end up floating through our creeks and rivers until they find their way to the sea.

But while these plastic bags are certainly not pretty, they actually cause real, tangible harm to the greater environment.

Plastic bags tend to disrupt the environment in a serious way. They get into soil and slowly release toxic chemicals. They eventually break down into the soil, with the unfortunate result being that animals eat them and often choke and die.

Below, we’ll examine a few of the most significant problems they cause and discuss the extent of the problem.


Environmental Damage Caused by Plastic Bags

Plastic bags cause several different types of harm, but three of the most troubling problems they present include the following:


Wildlife Harm

Animals suffer harm at the hands of plastic bags in a number of ways. Many animals – including both terrestrial and aquatic varieties – eat plastic bags, and suffer from serious health problems once they do.

A significant number of cows, for example, die each year after eating plastic bags that end up in their grazing grounds. This has been a particularly big problem in India, where cows are numerous and trash-collection sporadic.

Upon surgical examination, many of the cows injured by this plastic plague are found to have 50 or more plastic bags in their digestive tracts.

Animals who swallow plastic bags often suffer from intestinal obstructions, which typically lead to a long, slow and painful death. Animals can also be poisoned by the chemicals used to create the bags, or from chemicals that the plastic has absorbed while making its way through the environment.

And because plastic doesn’t break down very readily in the digestive tracts of animals, it often fills their stomachs. This causes the animals to feel full, even while they slowly waste away, eventually dying from malnutrition or starvation.

But while livestock and domestic animals are certainly at risk from plastic bags, some animals are suffering even greater harm. Already stressed by habitat destruction, decades of poaching and climate change, sea turtles are at particular risk from plastic bags, as they often mistake them for jellyfish – a popular food for many sea turtle species.

In fact, researchers from the University of Queensland recently determined that approximately 52 percent of the world’s sea turtles have eaten plastic debris – much of it undoubtedly originating in the form of plastic bags.

Microplastic fibers identified in the marine environment Photo by M.Danny25, via CC BY-SA 4.0


Clogged Sewage Systems

Even in urban areas, where wildlife is relatively scarce, plastic bags cause significant environmental harm. Runoff water collects and carries discarded plastic bags and ultimately washes them into storm sewers.

Once in these sewers, the bags often form clumps with other types of debris, and ultimately block the flow of water.

This prevents runoff water from properly draining, which often inconveniences those living or working in the area. For example, roads often flood when storm sewers become blocked, which forces them to be closed until the water drains.

This excess water can damage cars, buildings and other property, and it also collects pollutants and spreads them far and wide, where they cause additional damage.

Clogged storm sewers can also disrupt the water flow throughout local watersheds. Blocked sewer pipes can starve local wetlands, creeks and streams of the water they require, which can lead to massive die-offs and in some cases, total collapse.


Aesthetic Deterioration

There isn’t much of a debate about the aesthetic impact plastic bags have on the environment.

The vast majority of people would agree that plastic bags ruin the appearance of just about every imaginable habitat, from forests and fields to deserts and wetlands. But, this aesthetic deterioration isn’t a frivolous concern; it can actually have a significant impact on human health, culture and the economy.

Scientists have long known that views of natural landscapes provide a wealth of benefits. Among other things, natural habitats and greenspaces help to reduce recovery times and improve outcomes of hospital patients, they help to improve focus and concentration among children, they help to reduce crime and they help to increase property values.

But when these same habitats are littered with plastic bags and other types of debris, these benefits are reduced.

Accordingly, it is important to value the aesthetic value of natural habitats, take steps to reduce plastic bag pollution and address these issues when developing public policy.


The Extent of the Problem

It is difficult to grasp the scope of the plastic bag problem, despite the ubiquity of plastic bags in the landscape. No one knows exactly how many bags are littering the planet, but researchers estimate that 500 billion used around the globe each year.

A small percentage of these end up being recycled, and some people try to reuse old plastic bags for other purposes, but the vast majority of plastic bags are used a single time. Many are discarded into the trash, but a significant percentage end up polluting natural habitats.

Part of the reason that plastic bags are so problematic relates to their long lifespan. Whereas a paper towel breaks down in a month, and a piece of plywood may take a year to degrade, plastic bags persist for much longer – typically decades, and in some cases centuries.

In fact, plastic bags that make their way into rivers, lakes or oceans never completely biodegrade. Instead, they break down into smaller and smaller pieces, eventually becoming “microplastics,” which are less than 5 millimeters long.

But although these microplastics aren’t as visually intrusive as plastic bags, they still cause a number of problems for wildlife and the ecosystem as a whole.



As you can see, plastic bags are a significant environmental concern. As a species, we’ll need to carefully examine the challenges they present and implement strategies that are likely to reduce the amount of environmental damage they cause.

We’d love to hear your thoughts on the issue. What types of steps would you recommend we take to help limit the damage caused by plastic bags? Let us know in the comments below.


How do plastic bags affect the environment?

This post was originally published in June, 2012. It has been updated for accuracy and comprehensiveness.