The COVID-19 pandemic has generated more than eight million tonnes of plastic waste globally, with over 25,000 tonnes of it entering the oceans, according to a study.
The research, published in the journal Proceedings of the National Academy of Sciences, found that a significant portion of this ocean plastic debris is expected to make its way onto either beaches or the seabed within three to four years.
A smaller portion will go into the open ocean, eventually to be trapped in the centres of ocean basins, which can become garbage patches, and accumulate in the Arctic Ocean.
The researchers noted that the COVID-19 pandemic has led to an increased demand for single-use plastics such as face masks, gloves, and face shields.
The resulting waste, some of which ends up in rivers and oceans, is intensifying pressure on an already out-of-control global plastic problem, they said.
The team led by researchers at Nanjing University in China and University of California (UC) San Diego, US, used a newly developed ocean plastic numerical model to quantify the impact of the pandemic on plastic discharge from land sources.
They incorporated data from the start of the pandemic in 2020 through August 2021, finding that most of the global plastic waste entering the ocean is coming from Asia, with hospital waste representing the bulk of the land discharge.
The study stresses on the need for better management of medical waste in developing countries.
"When we started doing the math, we were surprised to find that the amount of medical waste was substantially larger than the amount of waste from individuals, and a lot of it was coming from Asian countries, even though that's not where most of the COVID-19 cases were," said study co-author Amina Schartup, an assistant professor at UC San Diego.
"The biggest sources of excess waste were hospitals in areas already struggling with waste management before the pandemic; they just weren't set up to handle a situation where you have more waste," Scartup said.
The Nanjing University MITgcm-plastic model (NJU-MP) used in the study works like 'a virtual reality', said Yanxu Zhang, the corresponding author and a professor at Nanjing University.
"The model simulates how the seawater moves driven by wind and how the plastics float on the surface ocean, degraded by sunlight, fouled by plankton, landed on beaches, and sunk to the deep," said Zhang.
The researchers found that most of the global plastic waste from the pandemic is entering the ocean from rivers.
Asian rivers account for 73 per cent of the total discharge of plastics, with the top three contributors being the Shatt al-Arab, Indus, and Yangtze rivers, which discharge into the Persian Gulf, Arabian Sea, and East China Sea.
European rivers account for 11 per cent of the discharge, with minor contributions from other continents, the researchers said.
While most of the pandemic-associated plastics are expected to settle on beaches and the seafloor, a smaller amount will likely end up circulating or settling in the Arctic Ocean.
The model shows that about 80 per cent of the plastic debris that transits into the Arctic Ocean will sink quickly, and a circumpolar plastic accumulation zone is modelled to form by 2025, the researchers said.
The Arctic ecosystem is already considered to be particularly vulnerable due to the harsh environment and high sensitivity to climate change, they said.
To combat the influx of plastic waste into the oceans, the researchers urge for better management of medical waste in epicentres, especially in developing countries.
The researchers called for global public awareness of the environmental impact of personal protection equipment (PPE) and other plastic products.
The also emphasised on the development of innovative technologies for better plastic waste collection, classification, treatment, and recycling, and development of more environmentally friendly materials.
