Plastic Pollution: The Sources And Their Impact

Plastic pollution is a pressing issue that affects all ecosystems, including land, freshwater, and marine environments. It is caused by a variety of sources, both land-based and marine, and has severe consequences for biodiversity, ecosystems, and human health. The main sources of plastic pollution are single-use products such as bottles, caps, cigarettes, shopping bags, cups, and straws, which are often improperly discarded and end up polluting the environment. Land-based sources, including urban and stormwater runoff, littering, industrial activities, tyre abrasion, construction, and agriculture, contribute significantly to plastic pollution. In the oceans, plastic pollution originates from land runoff, marine sources such as fishing gear and abandoned vessels, and microplastics formed by the breakdown of larger plastic pieces. Addressing plastic pollution requires collective action and a global approach, including reducing plastic production, improving waste management, and implementing international agreements to reduce plastic emissions.

Rivers and coastlines

The probability that mismanaged plastic waste enters the ocean varies a lot across the world, depending on factors such as the location and length of river systems, proximity to coastlines, terrain, and precipitation patterns. The latest analysis models the deterministic drivers of how plastic is transported using wind and precipitation patterns and river discharge data, as well as factors that affect the probability of plastic first entering rivers, then the ocean. These include the proximity of populations to the river, the distance to the ocean, the slope of the terrain, and types of land use.

The majority of plastic in the ocean spills out from rivers, but some sources suggest that the Great Pacific Garbage Patch is an exception, with 80% of its plastic coming from fishing activities at sea.

Research suggests that the top ten emitting rivers contribute a much smaller amount than previously thought: just 18% of plastics compared to 56% and 91% from previous studies. To account for 80% of river plastics, we need to include the top 1,000 to 1,656 rivers. Eight of these are in Asia: the Yangtze, Indus, Yellow, Hai He, Ganges, Pearl, Amur, and Mekong. Two are in Africa: the Nile and the Niger.

To prevent plastic from reaching the oceans, scientists and conservationists advocate for improved waste management systems and recycling, better product design that considers the short life of disposable packaging, and a reduction in the manufacturing of unnecessary single-use plastics.

Land-based sources

Plastic pollution is a pressing issue that affects all ecosystems, including land, freshwater, and marine environments. While marine sources like fishing nets, lines, ropes, and abandoned vessels contribute significantly to plastic pollution in the oceans, land-based sources remain the primary origin of this global issue.

Littering is another significant land-based source of plastic pollution. This includes intentional and unintentional littering of single-use plastic products such as bottles, caps, cigarettes, shopping bags, cups, and straws. These items are often not disposed of properly and can be blown away by the wind, ending up in rivers and oceans. Additionally, plastic waste in landfills can be blown away during transportation or when exposed to the elements, further contributing to land-based plastic pollution.

Industrial activities and construction sites also contribute to land-based plastic pollution. This includes the improper disposal of plastic waste generated during manufacturing, construction, or other industrial processes. Furthermore, certain products shed microplastics during their normal use, such as synthetic textiles and tyres, which contribute to the pollution through abrasion.

Agriculture is another land-based source of plastic pollution. Plastic used in agricultural practices, such as irrigation pipes, greenhouse coverings, or plastic mulch, can be left in fields and washed into water bodies by rain or irrigation practices. Additionally, plastic used in agricultural packaging, like fertilizer bags or seed containers, can end up in the environment if not properly disposed of.

To address plastic pollution effectively, a global approach is necessary to reduce plastic waste and improve waste management practices. While rivers are significant pathways for plastic to enter the oceans, the latest research suggests that the top ten emitting rivers contribute a smaller amount than previously thought. Therefore, mitigation efforts must consider a broader range of rivers and their unique characteristics, such as population density, distance to the ocean, slope of the terrain, and types of land use.

Industrial activities

Plastic pollution has various sources, one of the major ones being industrial activities. These activities contribute significantly to the problem of plastic waste and pollution on a global scale.

Plastic Production and Manufacturing

Plastic production and manufacturing are primary sources of plastic pollution from industrial activities. The process of extracting and refining fossil fuels, such as oil, natural gas, and coal, to produce plastic resins and polymers, results in the release of plastic pellets and particles into the environment. These pellets, often referred to as "nurdles," are the building blocks of plastic products. During transportation and handling, spills and accidental releases can occur, leading to pellet pollution in waterways and oceans.

The manufacturing of plastic products also generates plastic waste. This includes

Incineration

Incinerating plastic waste releases a range of toxic gases, heavy metals, and particles into the air. These pollutants include microplastics, bisphenols, and phthalates, and dioxins, which are highly toxic and can cause cancer, damage to the immune system, and interfere with hormones. Even state-of-the-art incinerators may emit potentially harmful amounts of these toxins, as some of them can pass through the filters. In addition, the electricity generated from plastic incineration is even dirtier than coal, contributing to climate change.

The burning of plastic waste is particularly prevalent in low- and middle-income countries, as well as in indigenous communities, where other waste disposal options may be limited. In Guatemala, for example, 71% of households burn waste as their primary means of disposal. However, the negative health impacts of burning plastic waste are well-documented, with outdoor air pollution being the single largest risk factor for ill health globally, contributing to millions of premature deaths each year.

Overall, incineration is an unsustainable and short-sighted solution to plastic pollution. While it may temporarily dispose of some plastic waste, it contributes to air pollution, climate change, and negative health outcomes for communities located near incinerators, particularly low-income communities. To effectively address plastic pollution, a focus on reducing plastic production and increasing reuse and recycling is necessary.

International trade

The high international trade in plastic waste is due to the finite lifespan of plastic products, which have become ubiquitous in the natural environment. The increasing consumption of plastic has led to an accelerated generation of plastic waste, and the global demand for plastics is projected to double by 2050. This has resulted in a rapid increase in plastic production, with half of all plastics ever manufactured being produced in the last 20 years. The growth in plastic production has outpaced the development of waste management infrastructure, leading to plastic pollution.

The mismanagement of plastic waste, including the lack of recycling, incineration, or sealed landfills, is a critical factor in plastic pollution. This mismanagement is more prevalent in low-to-middle-income countries due to poorer waste management infrastructure. As a result, most of the ocean plastics come from poorer countries, with a 2017 study estimating that Asian countries contributed 86% of plastic emissions to the ocean. The probability that mismanaged plastic waste enters the ocean varies depending on factors such as terrain, winds, precipitation, and river patterns.

To address plastic pollution from international trade, countries have enacted various national and subnational actions, such as bans on plastic bags or straws. Additionally, two international mechanisms exist to address the movement of plastics: the 2019 Basel Convention Plastic Waste Amendments and the Stockholm Convention on Persistent Organic Pollutants. However, there is currently no plastics-specific multilateral trade agreement at the World Trade Organization (WTO), leading to trade challenges. The current draft text of the international legally binding instrument (ILBI) on plastic pollution aims to end plastic pollution by 2040, and negotiations are ongoing to develop effective standards that consider the trade implications of plastic pollution measures.

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