Content Objectives
How Plastic is Created
The chemical makeup of plastic makes it indestructible and resistant to degradation. Plastic is made of organic molecules (monomers) joined together by covalent bonds to form a chain (polymers). These chains can also be “crosslinked”. The long chains of crosslinked polymers create strong bonds that give plastic its durability.8 During refinement, the monomers of plastic are produced using crude oil and natural gas from the ground as a raw material. In this process, fossil fuels are broken down into monomers such as ethylene from crude oil and propylene from natural gas. Next, the ethylene and propylene are bonded together to form polymers called resins. These resins are formed into plastic preproduction pellets called nurdles. The nurdles are sent to manufacturers and are heated and molded into different types of plastic products.9
Over the past half century, plastic has been used to create a wide range of products used across the globe. The makeup of plastic makes it both strong enough to endure a variety of elements, but also malleable to mold into different shapes. The chemical properties of plastic are low density, flexibility, transparency, chemical resistance, and stability.10 Plastic can be transparent and filled up with brightly colored sports drinks to be marketable for consumers. Pipelines made of plastic are stable and durable.11 More than 300 different types of plastics are made.12 The two largest categories of plastic are packaging and consumer institutional products. Packaging includes bottles, jars, vials, drums, pails, cans, barrels, baskets, food containers, and caps. Consumer and institutional products include cups, toys, sporting goods, personal care items, healthcare, and medical items.13 The uses of plastic seem endless which is why producing and selling plastic has grown into a multibillion-dollar industry. The global market for plastic was valued at $600 billion dollars in 2022 and is expected to grow at 4% from 2023 to 2030.
The advancement of the plastic industry began in the 1950s. After World War II, plastic production grew exponentially. During the war, plastic was used in new ways to create plastic helmets, water-resistant vinyl raincoats, and parachutes.14 Following the war, the plastic industry shifted from making war materials to consumer products. Americans were eager to buy appliances, clothing, and furniture, which were made from plastic. TV dinners grew in popularity which required lots of packaging, also made from plastic. As consumerism ingrained itself in American culture, the demand for plastic grew. This growth in demand in plastic products is not limited to the United States. Over the decades, global demand for plastic materials grew from producing 2 million tons per year in 1950 to producing 460 million tons per year in 2019 (Figure 1).
Although plastic can be recycled, new plastic is cheaper to produce, partly because the fossil fuel industry benefits from tax subsides. In 2015, the International Monetary Fund calculated U.S. energy subsidies to amount to $649 billion, with 80% going to natural gas and crude oil.15 Much of the public communication on plastic pollution has centered on individual choices. The public has been urged through campaigns to utilize reusable shopping bags, reusable water bottles, and to eliminate plastic straws. Changes to individual behavioral patterns is not enough to shift the impacts of plastic pollution. In order for structural change to occur, international agreements are needed. In 2022, 175 nations agreed to begin writing a UN plastic treaty to fight waste globally.16
Figure 1. Global plastic production has dramatically increased over the last 70 years.17
Single Use Plastic
The rapid increase in plastic utilization largely comes from the increase in single use plastics. Single use plastics are products that are designed to be used once and then discarded. For example, disposable water bottles and plastic packaging are everyday products. Single use products account for 50 percent of all plastic production globally.18 Plastic packaging makes up 40 percent of all single use plastics. Along with packaging, plastic shopping bags and containers are the top two categories in the United States. In the US more than 100 billion single use shopping bags were used in 2014. Single use plastic is ubiquitous and largely contributes to growing plastic pollution crisis.
Figure 2. Global plastic waste disposal from 1980 to 2015.19
Where Does Plastic Go?
A common misconception is that the majority of plastic is recycled. With the exception of the 12% that has been incinerated, all the plastic ever created is still on Earth. Globally, 79% of plastic waste is in a landfill or dumped and 12% is recycled (Figure 2).20 Discarded plastic can end up in solid waste management systems. In wealthy nations, the waste management systems are stronger. In nations with weaker waste management systems, plastic waste leaks into the environment. The plastic can travel to the coastline or ocean. Lastly, plastic breaks down into tiny pieces called microplastics and travels to the surface of the ocean and throughout ecosystems.
Recycling and Waste Management
In the 1980s – 1990s there was growing concern in the public about plastic waste. Prior to the 1980s plastic waste was only discarded. The sight of litter along beaches and other public places brewed angst in the public. The first Earth Day was in 1970, and there was a growing American counterculture towards the Vietnam war and environmental issues such as air pollution, land use, and global warming.21 The first Earth Day was a large environmental protest including millions of people across the United States and the world. To address the public backlash, the plastic industry launched campaigns to promote public responsibility. The industry lobbied legislatures to pass laws requiring a symbol on plastic to indicate its recyclability. The purpose of the symbols was to encourage individuals to put their waste in recycling bins.22
The highly recognizable recycling symbol is a triangle with a resin number in the center. The resin number represents a category of plastic and makes sorting plastic simpler. Certain types of plastic are easier and more beneficial to recycle than others. For example, water bottles and milk jugs are simple to recycle, but most packaging is not and while food containers and packaging may have a recycling symbol, many municipal recycling plants will not recycle them. The recycling process produces plastic of lesser quality than the original, known as downcycling. Lesser quality plastic is harder to sell.23
Figure 3. Global plastic waste exports in 2021.24
Disproportionate Burdens
Developing nations disproportionately bear the brunt of plastic pollution. The United States, Australia, and European nations trade their plastic waste to Asian and African nations (Figure 3). While China has imported the most plastic of any country, in 2018, China adopted a new policy refusing plastic waste from other countries.25 The following year, The Basel Convention attempted to scale back international trading of plastic waste. Over 180 countries passed agreements to limit exports of plastic waste from wealthy nations. The United States Congress did not pass legislations to ratify the agreement. Without signing the agreement there are no consequences for US companies that still export plastic waste. The receiving nations accept the imports because they can repurpose the materials into new goods.
Although China’s new policy decreased global trade of plastic by 50%, other nations in Asia such as, Malaysia, Vietnam, Indonesia, and India increased their plastic imports. African nations such as Ghana, Uganda, Tanzania, Ethiopia, Senegal, Zambia and Kenya are also now flooded with plastic waste. The receiving nations have inadequate waste management and have difficulty recycling the plastic. Unfortunately, plastic fills waterways, clogs roads and fields, and mixes into animal feed. Zambia has experienced many cholera outbreaks due to plastic clogged drainage systems.26
The presence of plastic recycling facilities in developing countries has given rise to waste pickers. Waste pickers sell plastic bottles and waste to private recycling companies. The work is extremely dangerous and time consuming. For instance, waste pickers working in a Nairobi dump can find plastic bottles with discarded syringes, broken glass, feces, fragments of cellphone cases, remote controls, shoe soles, trinkets, toys, pouches, clamshells, bags, and countless unrecognizable shreds of thin plastic fill.27 Young children search the dump daily for scraps with hope of earning money for their families or to pay for school. Waste pickers make very little, about 4 cents U.S. per kilogram of plastic.
Figure 4. Plastic debris on a beach in Indonesia.28
The weak recycling systems and waste management infrastructure in receiving nations also impacts coastal regions. Coastal communities are impacted economically. The aesthetics of polluted beaches deters tourists (Figure 4). Coastal areas depend on pristine, inviting beaches for tourism. However, tourists’ litter and exasperate the litter problem.29 The plastic debris on beaches adversely affects the tourism industry, leading to a loss of output, revenue, and employment. Beach cleanup is costly for any coastal town. In 2012, local governments in 90 towns in Washington, Oregon, and California spent an estimated $500 million dollars on beach cleanups.30 Towns in developing nations do not have the economic resources to invest in consistent beach cleanup. More trash appears soon after a beach cleanup.
The Ocean
Plastic enters the ocean from land, rivers, and abandoned fishing equipment. 80 percent of the plastic in the ocean comes from land (Figure 5). Half of all plastic pollution comes from five countries in the same geographic region: China, Indonesia, The Philippines, Thailand, and Vietnam.31 Wealthy nations have a higher rate of plastic use than lower income nations. However, plastic waste enters the oceans the most in lower income countries because of the lack of waste management system. In middle-income countries, more people have the ability to purchase products that inevitably become waste. These nations have the economies that produce their own plastic pollution, but still lack the resources to discard the plastic waste properly and safely. Waste is disposed of in dumpsites, landfills, or by illegal dumping.32 Dumpsites are known to add 1.1–1.3 million tons of marine plastic every year.33 Thailand alone has 2,380 dumpsites. Over 970 dumpsites are located near bodies of water or along the coastline. Waste at two dumpsites in Thailand were studied and found that plastic waste was 45.25% and 39.12% of the total waste.34
Figure 5: Percentage of plastic debris the enters the ocean from rivers.35
The plastic debris leaks from waste systems to rivers. Recent studies indicate that smaller rivers play a bigger role in emitting plastic, which makes mitigation efforts more challenging (Figure 5). Now 1,656 rivers are estimated to contribute 80% of plastic into the ocean. The Philippines accounts for 36 percent of all plastic input into the ocean and seven of the top ten rivers that leak plastic into the ocean are in the Philippines. Most of the population in the Philippines lives along the coastlines.
Once the plastic is emitted to the ocean, it is difficult to retrieve. Plastic debris can fill up with water and reaches the ocean floor. Bottles from the 1960’s have been found on the seabed.36 Plastic bottles are estimated to last for thousands of years at the bottom of the ocean. The lack of light and less oxygen at the bottom of the ocean makes the plastic decay very slowly. Plastic also floats along the ocean’s surface. Large quantities of floating plastic debris end up in garbage patches. Around 60% of all plastic created is less dense than seawater, which makes it easy to travel the ocean’s surface via winds and currents. Large systems of rotating currents are called gyres. Within the gyres are patches of plastic debris swirling around. These gyres are referred as garbage patches.37 There are five gyres in the ocean. One in the Indian, and two each in the Atlantic and Pacific Oceans.
The most well-known garbage patch is the Great Pacific Garbage Patch (GPGP) located between California and Hawaii. In the GPGP, it is predicted that at least 79 thousand tons of ocean plastic are floating inside an area of 1.6 million kilometers.38 A study of the GPGP found plastic fragments from containers, bottles, lids, eel trap cones, oyster spacers, ropers, and fishing nets. Debris origins dated back as far as 1977, and nine different languages were identified. Marine equipment makes up the 46% of the GPGP cluster.39 There is evidence that plastic pollution levels are increasing within the GPGP. Although plastic flows out of the GPGP, plastic flows into the gyre at a greater rate. The Great Pacific Garbage Patch is not a literal patch of litter floating on the ocean like an island. Instead, the trash is scattered over large areas of the ocean from the surface down to the ocean floor.
Microplastics
Scientists only know where 1% of the plastic is in the ocean. The majority of plastic has been physically broken down into small pieces, called microplastics. Microplastics are about a third of a millimeter in diameter. The amount of microplastics in the ocean is unknown. At this small size, microplastics are impossible to retrieve from the ocean. As a result, the microplastics become part of the marine ecosystem. Microplastics are in permanent transit in the ocean and has become part marine ecosystems. Once in the environment, microplastics are transported through the ocean currents and the air. Microplastics have been found all over the world, from the arctic, to Mount Everest, and at the bottom of the Mariana Trench.40
Microplastics can also be transported via the food web, from prey to predators. Studies have found that as microplastics travel through the ocean, they can adsorb other chemicals in the ocean. When plankton eat the microplastics, it transfers chemicals to marine animals. Microplastics have been found in thousands of species.41 Microplastics may have an adverse effect on the developmental reproduction pattern of marine organisms.42 In a study by marine biologist, Chelsea Rochman, plastic was found in a third of fish and one fourth of oysters from Californian and Indonesian fish markets.
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