Plastic litter: Where does it come from?


It is likely that in one of your trips, or even in your hometown, you have come across a beach covered with plastic objects and pieces. When that happened to me in a natural park at the Pacific Coast of Costa Rica, I felt angry at tourists for being untidy, so I started to collect some of the items. I was thus astonished when some volunteers of the park told me that plastics were actually coming from the sea day after day. I realized that I did not have any clue about plastic pollution, so I started researching more to understand where all this plastic was coming from. Here I present you some interesting and important facts!

National ​​Wildlife Refuge Romelia, Montezuma, Pacific Coast of Costa Rica, April 2019.

A total of 80% of marine plastic litter has land-based sources and is especially due to direct and indirect dumping of plastic waste in rivers and oceans. Rivers can transport waste into the ocean, where tides and currents transport it around the globe to even the most remote places. Plastic is non-degradable, so it stays in the environment for hundreds of years, where it breaks down into smaller pieces. Marine litter damages terrestrial and aquatic ecosystems, as well as marine-based economic sectors such as tourism and fisheries. There starts to be advanced technology to rid the oceans and rivers of plastic, but why do they end up there in the first place?

Mass of river plastic flowing into oceans related to the mismanaged plastic waste (MPW) production, both in tonnes per year. Source: Lebreton et al., 2017.

Low-income countries lack municipal waste-collection systems that deliver garbage to recycling centers and/or landfills. In Africa and South Asia, more than 85% of the population do not have access to minimum waste management services. Residents have no other option than throwing the mismanaged waste into the rivers and dumpsites or burning it. In many cases, dumpsites are intentionally located near rivers or on the coast so that part of the waste is carried away by heavy rains. Rivers in Asia are responsible for 86% of plastics that enter the ocean through rivers. Apart from polluting rivers and the oceans, plastic waste can block drains and increase the risk of flooding and the breeding of vectors of infectious diseases. If burned uncontrollably, waste creates black carbon emissions (contributing to climate change) and releases cancer-causing compounds and other toxic substances.

On the left, old dumpsite next to the Mediterranean Sea in Lebanon. On the right, waste burning in Nepal. Sources: ISWA, 2017, Wilson et al., 2015.

In addition, high-income countries have traded a significant portion of their recyclable plastics to low- and middle-income countries, especially China and South Asia. This is due to the lack of technology and high price of recycling and disposing plastic waste in high-income countries. In 2014, the percentage of recycled plastic waste was as low as 30% in Europe (see recycling rates per country here), 25% in China and 9% in the United States. Thus, recycling symbols on plastic packaging mean that the product CAN BE recycled but do not imply that the product is actually recycled. Plastic recycling is technically complex due to the existence of different types of plastic. Sorting each type is not 100% accurate, and a mixture of plastic types can damage the machines that produce plastic or can slow down the production. Since virgin plastic is very cheap to produce, manufacturers prefer not to take the risk of using recycled plastic.

The challenge of recycling. Ease of recycling and percentage of global plastic waste for different types of plastic polymers in 2015. Source: National Geographic, 2018.

But why are so many products made from plastic? Well, plastic is a material with very interesting properties, such as reduced weight, strength, durability, flexibility, and sterility. This is why they have played a significant role in revolutionizing healthcare and many other industries. In addition, while paper products degrade much faster than plastic, they also require a vast amount of natural resources to create. Biodegradable plastics are becoming a popular replacement as consumers demand green alternatives, but they don’t always break down in sea water. For all these reasons, the solutions to the plastic crisis are:

In the short term, leakage should be stopped by providing collection service to all and by better regulating the transboundary movement of plastic waste. In the medium term, we need a paradigm shift where we see plastic litter as a resource, not as waste. In that sense, there are very interesting initiatives that show how giving incentives to plastic recycling reduces plastic littering, including Precious Plastic, Plastic Bank and Plastic Bottle Village. In the long term, we should move from the linear use of plastics to a New Plastics Economy, based in a circular economy where materials are designed to be reused and recycled.

Recycling of plastic can avoid environmental pollution, health hazard and climate change, while providing a net benefit for the economy, through jobs and added value! What are we waiting for?


EEA (European Environmental Agency). The plastic waste trade in the circular economy [Internet]. [Accessed 10 May 2020].

Geyer, R., Jambeck, J. R., & Law, K. L. (2017). Production, use, and fate of all plastics ever made. Science advances, 3(7), e1700782.

ISWA (International Solid Waste Association). (2017). Prevent marine plastic litter -Now!

Lebreton, L. C., Van Der Zwet, J., Damsteeg, J. W., Slat, B., Andrady, A., & Reisser, J. (2017). River plastic emissions to the world’s oceans. Nature communications, 8, 15611.

National Geographic. (2018). We made plastic. We depend on it. Now we’re drowning in it [Internet]. [Accessed 09 May 2020].

Wilson, D. C., Rodic, L., Modak, P., Soos, R., Carpintero, A., Velis, K., et al. (2015). Global waste management outlook. UNEP.