About 40 percent of seabirds surveyed around the world had toxic substances derived from plastic waste in their bodies amid concern over marine plastic pollution, according to a recent study by two Japanese universities.

The research conducted by Hokkaido University and Tokyo University of Agriculture and Technology from 2008 to 2016 found that about 43 percent of the seabirds had ingested toxic chemicals such as ultraviolet absorbers.

Harmful substances such as brominated flame retardants and phthalate esters were also detected in most of the birds tested in 12 of the 15 regions surveyed, including Awashima Island in Niigata Prefecture.

The research group examined 150 seabirds covering 37 species in 15 regions including areas in the Bering Sea, the Galapagos Islands, Greenland, Hawaii, and waters near Australia by taking fat samples secreted from glands near the birds’ tails.

“The (maritime plastic) pollution has spread even to polar regions,” Hideshige Takada, a professor at Tokyo University of Agriculture and Technology, said in a recent interview.

“We need to further examine such seabirds as albatrosses in Hawaii, which are highly affected by various toxic chemicals, to see if they have shown any sign of the impact,” he said.

The research showed nine species, such as the albatross in Hawaii and on Marion Island near the South Pole, face a serious risk from marine pollution because they also carried other contaminants not related to plastic waste.

Plastics, used in grocery bags, bottles and many other products, do not disintegrate naturally in the environment. The Organization for Economic Cooperation and Development has estimated in a report that the annual inflow of plastic waste to the oceans was 4 million to 12 million tons in 2010, and that it greatly affected the marine ecosystem and environment and damaged the fishing and tourism industries.

There will be more plastic than fish in the oceans by 2050, according to an estimate by the United Nations.

During the Group of Seven summit in June, only Japan and the United States failed to endorse the group’s Ocean Plastics Charter to cut plastic waste.