Plastic pollution is the accumulation of plastic objects and particles (e.g.
plastic bottles, bags and microbeads) in the Earth's environment that adversely
affects humans, wildlife and their habitat.[1][2] Plastics that act as pollutants
are categorized by size into micro-, meso-, or macro debris.[3] Plastics are
inexpensive and durable, making them very adaptable for different uses; as a
result, manufacturers choose to use plastic over other materials.[4] However, the
chemical structure of most plastics renders them resistant to many natural
processes of degradation and as a result they are slow to degrade.[5] Together,
these two factors allow large volumes of plastic to enter the environment as
mismanaged waste which persists in the ecosystem and travels throughout food webs.
[6][7]
Plastic pollution can afflict land, waterways and oceans. It is estimated that 1.1
to 8.8 million tonnes of plastic waste enters the ocean from coastal communities
each year.[8] It is estimated that there is a stock of 86 million tons of plastic
marine debris in the worldwide ocean as of the end of 2013, with an assumption that
1.4% of global plastics produced from 1950 to 2013 has entered the ocean and has
accumulated there.[9] Global plastic production has surged from 1.5 million tons in
the 1950s to 335 million tons in 2016, resulting in environmental concerns. A
significant issue arises from the inefficient treatment of 79% of plastic products,
leading to their release into landfills or natural environments.[10]
Some researchers suggest that by 2050 there could be more plastic than fish in the
oceans by weight.[11] Living organisms, particularly marine animals, can be harmed
either by mechanical effects such as entanglement in plastic objects, problems
related to ingestion of plastic waste, or through exposure to chemicals within
plastics that interfere with their physiology. Degraded plastic waste can directly
affect humans through direct consumption (i.e. in tap water), indirect consumption
(by eating plants and animals), and disruption of various hormonal mechanisms.[12]
As of 2019, 368 million tonnes of plastic is produced each year; 51% in Asia, where
China is the world's largest producer.[13] From the 1950s up to 2018, an estimated
6.3 billion tonnes of plastic has been produced worldwide, of which an estimated 9%
has been recycled and another 12% has been incinerated.[14] This large amount of
plastic waste enters the environment and causes problems throughout the ecosystem;
for example, studies suggest that the bodies of 90% of seabirds contain plastic
debris.[15][16] In some areas there have been significant efforts to reduce the
prominence of free range plastic pollution, through reducing plastic consumption,
litter cleanup, and promoting plastic recycling.[17][18]
As of 2020, the global mass of produced plastic exceeds the biomass of all land and
marine animals combined.[19] A May 2019 amendment to the Basel Convention regulates
the exportation/importation of plastic waste, largely intended to prevent the
shipping of plastic waste from developed countries to developing countries. Nearly
all countries have joined this agreement.[20][21][22][23] On 2 March 2022, in
Nairobi, 175 countries pledged to create a legally binding agreement by the end of
the year 2024 with a goal to end plastic pollution.[24]
The amount of plastic waste produced increased during the COVID-19 pandemic due to
increased demand for protective equipment and packaging materials.[25] Higher
amounts of plastic ended up in the ocean, especially plastic from medical waste and
masks.[26][27] Several news reports point to a plastic industry trying to take
advantage of the health concerns and desire for disposable masks and packaging to
increase production of single use plastic.[28][29][30][31]
Causes
See also: Timeline of plastic development
The pathway by which plastics enters the world's oceans
There are differing estimates of how much plastic waste has been produced in the
last century. By one estimate, one billion tons of plastic waste have been
discarded since the 1950s.[32] Others estimate a cumulative human production of 8.3
billion tons of plastic, of which 6.3 billion tons is waste, with only 9% getting
recycled.[33][34][35]
It is estimated that this waste is made up of 81% polymer resin, 13% polymer fibres
and 32% polymer additives. In 2018 more than 343 million tonnes of plastic waste
were generated, 90% of which was composed of post-consumer plastic waste
(industrial, agricultural, commercial and municipal plastic waste). The rest was
pre-consumer waste from resin production and manufacturing of plastic products
(e.g. materials rejected due to unsuitable colour, hardness, or processing
characteristics).[35]
A large proportion of post-consumer plastic waste consists of plastic packaging. In
the United States plastic packaging has been estimated to make up 5% of MSW. This
packaging includes plastic bottles, pots, tubs and trays, plastic films shopping
bags, rubbish bags, bubble wrap, and plastic or stretch wrap and plastic foams e.g.
expanded polystyrene (EPS). Plastic waste is generated in sectors including
agriculture (e.g. irrigation pipes, greenhouse covers, fencing, pellets, mulch;
construction (e.g. pipes, paints, flooring and roofing, insulants and sealants);
transport (e.g. abraded tyres, road surfaces and road markings); electronic and
electric equipment (e-waste); and pharmaceuticals and healthcare. The total amounts
of plastic waste generated by these sectors is uncertain.[35]
Several studies have attempted to quantify plastic leakage into the environment at
both national and global levels which have highlight the difficulty of determining
the sources and amounts of all plastic leakage. One global study has estimated that
between 60 and 99 million tonnes of mismanaged plastic waste were produced in 2015.
Borrelle et al. 2020 has estimated that 19–23 million tonnes of plastic waste
entered aquatic ecosystems in 2016. while the Pew Charitable Trusts and SYSTEMIQ
(2020) have estimated that 9–14 million tonnes of plastic waste ended up in the
oceans the same year.
Despite global efforts to reduce the generation of plastic waste, losses to the
environment are predicted to increase. Modelling indicates that, without major
interventions, between 23 and 37 million tonnes per year of plastic waste could
enter the oceans by 2040 and between 155 and 265 million tonnes per year could be
discharged into the environment by 2060. Under a business as usual scenario, such
increases would likely be attributable to a continuing rise in production of
plastic products, driven by consumer demand, accompanied by insufficient
improvements in waste management. As the plastic waste released into the
environment already has a significant impact on ecosystems, an increase of this
magnitude could have dramatic consequences.[35]
The trade in plastic waste has been identified as "a main culprit" of marine
litter.[a] Countries importing the waste plastics often lack the capacity to
process all the material. As a result, the United Nations has imposed a ban on
waste plastic trade unless it meets certain criteria.[b]
