Quick hits on what you need to know about plastic waste
How plastic enters the environment in the first place
Plastic pollution is one of the biggest threats to the planet’s well-being. With 40 per cent of plastics manufactured for packaging and other single uses (bottles, cutlery, bags, cups), much of the junk from our throwaway culture is meant to become waste. While an estimated 12 per cent of plastic waste is incinerated (much of it from medical facilities) and another nine per cent recycled, most plastic waste is diverted to landfills. That’s the plastic that has been disposed of for garbage collection. In reality, tonnes of plastic waste ends up polluting the environment, inadvertently or through negligence.
Even if we properly dispose of that empty chip bag in a garbage can in our local park, the wind might scatter it; ditto the waste that ends up in landfills. In some cases, people simply toss their junk on streets or in nature. Of all this land-based waste, some will eventually end up in our rivers and, ultimately, our oceans. Some nations around the world have laws that prohibit dumping of waste into the sea, whether from land or from ships at sea. Where these laws don’t exist — and where they are difficult to enforce, such as on the high seas — plastic waste and old fishing gear are sometimes thrown overboard.
Did you know?
Like everything else, garbage goes where gravity takes it. It rolls downhill, so litter on streets, for instance, gets flushed into the storm sewer, and then into rivers, which carry the litter to the oceans.
Say no to single-use plastics; instead of buying a bottle of water, keep a refillable stainless steel or other reusable bottle handy.
Harm to the environment caused by plastic
Because plastic is not biodegradable, when plastic waste enters the environment — be it on your own street or in your favourite national park — it’s potentially there forever, even when the forces of nature break it into smaller pieces. Some of the harm caused by this debris includes:
- Plastic production creates climate change-causing greenhouse gas emissions. According to a 2019 report by the Center for International Environmental Law that looked at the hidden costs of plastic as a contributor to climate change, plastic production and incineration in 2019 alone will contribute some 850 million tonnes of carbon dioxide emissions; that number could rise to 56 billion tonnes by 2050 if plastic production is not curbed.
- In landfills, plastic fragments can leach chemicals into the ground and groundwater below.
- In lakes and oceans, micro- and macroplastics both contribute to pollution; there, they can either leach chemicals, or they absorb other chemical compounds from the surrounding water.
- Depending on the chemical composition of a plastic polymer, it can absorb potentially harmful chemical compounds, making them more toxic over time.
- Plastic waste in the environment is also an eyesore. Who wants to see plastic bottles strewn on beaches or coffee cups in alpine meadows? This is a reality we can all take action to prevent.
Microplastics in soil and freshwater
Measuring less than five millimetres, microplastic particles manage to infiltrate not only oceans. They are also found in soil, where they could potentially leach chemicals that can make their way into crops or groundwater. These tiny filaments have also been found in the Great Lakes and in rivers. In freshwater, as in salt water, microplastics can absorb other pollutants and chemicals, becoming more toxic than the original plastic itself. Microplastics have been found in tap water, and are starting to show up in greater concentrations in food items such as honey and table salt. And in the past couple of years, scientists have even found these particles in the air we breathe (some of these filaments are so small you need a microscope to see them), potentially filtering through our lungs into the bloodstream.
Harm to people and animals caused by plastic
- Chemicals are sometimes added to plastics during production to give them a certain characteristic or appearance. Phthalates are used to make a plastic bendable or squishy (garden hoses, toys), while Bisphenol A (BPA) is added to create a resilient clear plastic for bottles or to make the lining in metal food cans. These additives can be harmful to human health when the plastic breaks down — phthalates are a carcinogen, and BPA is a hormone disruptor.
- Microplastics and microfibres from synthetic textiles make up most of the plastics found in oceans, lakes and rivers (on beaches adjacent to wastewater outlets there’s an abundance of microfibres that originate from clothes made from nylon and polyester). Unlike cotton and wool, these fibres are not biodegradable, and can bind to other pollutants such as flame retardants and pesticides to form toxic molecules that are consumed by plankton and other micro-organisms, and move up the food chain all the way to our dinner plates (see “Impacts on food chain” below).
- Macroplastics, on the other hand, cause animal death by entanglement and choking. Six-pack rings strangle birds on land and in marine environments. Plastic bags are ingested by whales, preventing nutrients from being absorbed or even bursting their stomachs. Seals and other marine mammals get caught in fishing gear and drown. And turtles eat bags and wipes, mistaking them for jellyfish.
- Fishing nets are also a major pollutant. Long after being discarded because it’s cheaper to buy new nets than mend old ones, they continue to trap and entangle marine organisms, hence their nickname “ghost nets” or “ghost fishing gear.” Whales, turtles and birds get entangled and die in these nets and the ropes attached to them. This abandoned fishing gear also traps more debris floating around, and eventually they become so heavy they are difficult (if not impossible) to remove and are left in the water.
Impacts on food chain
When plastics, such as polypropylene, PET and polyester, are broken into smaller pieces, the result is more surface area onto which chemicals and other pollutants can attach. So, it’s not only the plastic per se that’s harmful, but the chemicals that hitch a ride with them and accumulate in higher concentrations the higher up in the food chain they travel. Filter feeders, such as oysters and mussels, filter the water around them, including these pollutant-laden microparticles, which get lodged in their tissue. Fish also consume these particles, ingesting them and the pollutants carried with them. Birds then eat those fish, accumulating plastic and other pollutants in their bodies. People eat those fish and oysters, and sometimes the birds that feed on those marine creatures, and studies have shown that plastic microfibres and the pollutants carried by them have accumulated in our bodies, too.