The widespread use of face masks due to the COVID-19 pandemic may result in unintended consequences, with one study showing that about 1.56 billion will end up polluting the ocean in 2020, Washington Examiner reported.

“The 1.56 billion face masks that will likely enter our oceans in 2020 are just the tip of the iceberg,” said Dr. Teale Phelps Bondaroff, director of research for OceansAsia, one of the study’s authors.

While masks may be the most visible symbol of the coronavirus pandemic, they aren’t the only plastic adding pollution to the oceans in 2020. Gary Stokes, the director of operations at OceansAsia, pointed out that many plastic products have seen increased usage this year. “Hygiene concerns and greater reliance on take-away food has led to increased use of plastics, particularly plastic packaging,” Stokes said. “Meanwhile, a number of measures designed to reduce plastic consumption, like single-use plastic bag bans, have been delayed, paused, or rolled back.”

“Marine plastic pollution is devastating our oceans,” Stokes said. “Plastic pollution kills an estimated 100,000 marine mammals and turtles, over a million seabirds, and even greater numbers of fish, invertebrates and other animals each year. It also negatively impacts fisheries and the tourism industry, and costs the global economy an estimated $13 billion USD per year.”

The study’s authors say that using reusable masks could help to alleviate the pollution while calling on governments to implement policies such as littering fines and updating public health guidelines.