TUESDAY, Nov. 9, 2021 (HealthDay News) -- While the lockdowns of the pandemic may have done the planet's atmosphere a favor, a new study predicts that discarded masks, gloves and face shields will add more than 25,000 tons of plastic waste to the world's oceans.
Researchers from Nanjing University's School of Atmospheric Sciences in China and the University of California, San Diego (UCSD) Scripps Institution of Oceanography used a new model to project how much pandemic-related plastic waste there will be and where it will go.
The investigators found that, in total, 8 million tons will be produced, with a significant portion of this ocean plastic debris ending up on beaches or in the seabed within three to four years.
A smaller amount will go into the open ocean, where it will be trapped in the centers of ocean basins or subtropical gyres and a circumpolar plastic accumulation zone in the Arctic Ocean.
Most of the global plastic waste entering the ocean is coming from Asia and is hospital waste, the researchers found, using data from the start of the pandemic in 2020 through August 2021.
"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 Scripps Oceanography.
"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," she noted in a UCSD news release.
Most of the plastic is entering the ocean from rivers, and these areas require special attention in plastic waste management, the study authors noted.
About 73% of the discharge of plastic was in Asian rivers. The top three contributors were the Shatt al-Arab, Indus and Yangtze rivers. Those waterways discharge into the Persian Gulf, Arabian Sea and East China Sea.
European rivers were second, with 11% of the discharge. Other continents made minor contributions to the plastic waste, the findings showed.
The new Nanjing University model was built based on Newton's laws of motion and the law of conservation of mass, and works like "a virtual reality," explained Yanxu Zhang, corresponding author and a professor at the School of Atmospheric Sciences 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," Zhang said. "It can be used to answer 'what if' questions, for example, what will happen if we add a certain amount of plastics to the ocean?"
A circulation pattern in the ocean means a small amount of the plastics will end up circulating or settling in the Arctic Ocean, which is already considered vulnerable because of its harsh environment and high sensitivity to climate change. This appears to be a "dead-end" for plastic debris transported into it due to ocean circulation patterns, according to the authors.
About 80% of the plastic debris that transits into the Arctic Ocean will sink quickly, and a circumpolar plastic accumulation zone is modeled to form by 2025.
The study authors called for better management of medical waste in epicenters, especially in developing countries, as well as global public awareness of the environmental impact of personal protection equipment (PPE) and other plastic products. They also suggested development of innovative technologies for better plastic waste collection, classification, treatment and recycling, and development of more environmentally friendly materials.
"Indeed, the COVID-related plastic is only a portion of a bigger problem we face in the 21st century: plastic waste," said Zhang. "To solve it requires a lot of technical renovation, transition of economy, and change of lifestyle."
The U.S. National Oceanic and Atmospheric Administration has more on plastic waste in the ocean.
SOURCE: University of California, San Diego, news release, Nov. 8, 2021