Marine Plastic Waste Pollution Control
Marine plastic waste pollution control
Plastic waste in the ocean
Lightweight and durable plastic products have been widely used worldwide since their mass production in the 1960s. In the 1990s, plastic pollution gradually became an important issue in environmental pollution, especially plastic waste and microplastic pollution in the ocean, which became urgent global marine environmental problems to be solved.
Many plastic wastes are difficult to degrade and persist in the marine environment, and the potential risks of small marine plastic wastes, namely microplastics, to the marine ecosystem have also drawn attention to the issues of marine plastic waste and microplastics. At present, there is no legally binding action at the global level internationally. There is still a long way to go from pollution to remediation of plastic waste and microplastics in the ocean.
Definition of Plastic Waste and Microplastics
Non fiber microplastics and fiber microplastics:
Plastic waste refers to plastic material waste that leaks into the environment without proper disposal. Microplastics are small plastics with a diameter less than 5 mm, mainly divided into non fiber microplastics and fiber microplastics. Non fiber microplastics are plastic particles with different compositions, sizes, shapes, and densities. Additionally, the size of microplastics can be further subdivided based on the feeding size of plankton.
These plastic particles also have different compositions and surface effects, and are considered to pose the same environmental risks as large plastic waste. Plastics smaller than 1 μ m are defined as nanoplastics and require further research and understanding.
Marine plastic waste raises concerns
The surge of plastics:
In 2022, the Organization for Economic Cooperation and Development's (OECD) Global Plastic Outlook report showed that global annual plastic production increased from 234 million tons in 2000 to 460 million tons in 2019, and plastic waste increased from 156 million tons in 2000 to 353 million tons in 2019.
6.9 billion tons of plastic waste:
If we consider the loss of plastic waste in the recycling process, 220 million tons of plastic waste leaked into the environment in 2019, with microplastics accounting for 12% and poorly managed waste accounting for as much as 82%. As of 2015, humans have generated at least 6.9 billion tons of plastic waste.
Plastic products floating in the ocean:
According to statistics, there are over 5 trillion floating plastic products in the ocean, and surface plastic waste mainly accumulates in the five major eddies of the global ocean. The distribution density of marine plastic waste and microplastics is mainly concentrated in densely populated areas, and pollution has similarities.
These are just plastic pollution that can be monitored on the surface of the ocean. More plastic may be present in the seabed or other layers of the ocean, with microplastics in surface water accounting for about 2% of the total. The 2021 United Nations Environment Programme (UNEP) assessment report shows that plastic waste in the ocean currently accounts for approximately 85% of the total weight of marine litter.
Potential ecological risks
The hazards of plastics in the ocean:
Poor management of plastic waste, which leaks into the marine environment through different pathways and is ingested by marine organisms, or is physically damaged by entanglement, as well as the ecological risks of harmful trace organic pollutants that may be carried on the surface of plastics, are all worthy of attention.
The risks of large plastic waste can be mainly divided into navigation and industrial hazards, fisheries and aquaculture, and risks affecting biodiversity. Marine microplastics, due to their small particle size, are easily ingested by marine organisms and may lead to the absorption of harmful substances by living organisms, thus they can be transmitted in the food chain. The pathogenic microorganisms attached to the surface of microplastics may also pose a risk of transmission.
People still need to further understand the marine environmental risks of microplastics, and there is a lack of awareness of the risks of nanoplastics in the environment. There is currently no conclusive evidence to suggest any health risks associated with human exposure to microplastics through diet and respiration.
International efforts to address the issue of marine plastic waste
AHEG:
At the United Nations Environment Assembly, multiple meetings have focused on the theme of marine plastic waste, and an open-ended ad hoc expert group (AHEG) has been established to promote global conventions and regional cooperation actions for the prevention and control of marine plastic waste pollution. In international conventions, the United Nations Convention on the Law of the Sea, the Stockholm Convention on Persistent Organic Pollutants, and the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal all address the issue of marine plastic waste.
GESAMP
In 2019, the United Nations Environment Programme's Joint Expert Group on Marine Environmental Protection Science (GESAMP) conducted a risk assessment of marine plastic waste and microplastics, and released an assessment report to provide guidance on the impact and risks of marine plastic waste and microplastics on the ecological environment and human health, as well as decision-making and action. The Fourth United Nations Environment Assembly (UNEA 4) calls for strengthening scientific research and technical knowledge sharing and cooperation on marine plastics.
At the same time, China established the Regional Training and Research Center for Marine Plastic Waste and Microplastics of the Intergovernmental Marine Science Committee of UNESCO. Chinese scientists also contributed to the preparation of the White Paper on the "Marine Waste Hotspot Assessment Method" project by the United Nations Environment Programme in 2019 and the report "From Pollution to Solutions: Global Assessment of Marine Waste and Plastic Pollution" in 2021.
The full lifecycle process of plastics and carbon cycle
petroleum based plastics:
In the production process of petroleum based plastics, petroleum is refined and cracked into monomers, which are polymerized to produce high molecular weight polymers. After adding additives and a series of design and manufacturing processes, they become plastic products circulating in the market. Some of the plastic waste and microplastics generated after plastic production and use are abandoned by consumers, some are buried in landfills, and some are incinerated or recycled.
Pollution control throughout the entire lifecycle of plastics
Throughout the entire lifecycle of plastics, targeted measures should be taken for green and low-carbon design at every stage of product production, consumption, packaging, transportation, waste management, and even leakage into the environment to avoid environmental pollution.
In the upstream, there should be increased advocacy for offshore oil and gas companies regarding product environmental design, the construction of zero waste communities for consumer use, and the change of incineration policies and promotion of garbage classification in downstream waste management. For plastic waste leaked into the environment, river and beach clean-up activities should be carried out to achieve the goal of clean oceans.
Pollution and Prevention of Materials and Microplastics
The monitoring methods for plastic waste and microplastics in marine plastic pollution control face the challenge of consistency, and further scientific research is needed on the development of standardized methods, the flux of plastic waste entering the sea, and their transportation and accumulation worldwide. In terms of plastic management, the progress of the blueprint for plastic lifecycle management and the development of plastic circular economy is slow. The negotiation of a legally binding global "plastic convention" involving the full lifecycle management of plastics remains a daunting task.
The international convention to end plastic pollution ultimately requires humanity to develop new technologies to achieve a plastic circular economy. It is necessary to further optimize plastic product design, develop efficient, environmentally friendly, and high recovery green chemical waste plastic recycling technologies, implement innovative plastic product management and recycling circular economy models, maximize the reusability of plastic products, and ultimately eliminate the generation of waste plastics that may enter the environment.
The solution to plastic pollution is not only dependent on the government, enterprises, scientists, and non-governmental organizations, but also on the conscious actions of every citizen. All stakeholders should work together to solve the problem of plastic waste pollution, make better use of plastics, and jointly address the issues of marine plastic waste pollution and microplastics through multi-party collaboration.
