Greenpeace said its scientists gathered water and snow samples from Antarctica during a visit between January to March of this year. Laboratory tests confirmed the effect of humanity on the continent.
"It was about one microplastic piece at least per liter. When you think of extrapolating that out to the scale or the Antarctic Ocean, it's really, really significant," said Greenpeace's Louisa Casson.
She noted that, in the past, scientists thought the currents around the Antarctic Ocean might protect it from plastic pollution found in much of the world's oceans. But now, she said, evidence is increasingly showing that there might be little, if any, protection.
Microplastics are extremely small particles of plastic. They come from the breakdown of bottles and other plastic waste in the world's oceans.
In addition to microplastics, the Greenpeace study also confirmed the presence of chemicals known as per- and polyfluorinated alkylated substances. These chemicals are widely used in industrial processes, and have been linked to reproductive and developmental problems for wildlife.
"This just strengthens the rationale for why we need to be taking action on land to stop that flow of plastic into the ocean, but also creating huge ocean sanctuaries at sea to allow wildlife to recover from these pressures," Casson said.
The United Nations estimates that 8 million tons of plastic are dropped into the oceans every year. Plastic has been shown to harm wildlife.
An example of this happened several days ago in southern Thailand. That was when a pilot whale died after swallowing 80 pieces of plastic waste. Tests showed the waste weighed about eight kilograms.
International concern about plastic pollution is rising. In India, Prime Minister Narendra Modi recently promised to ban all single-use plastic by 2022. In the city of Mumbai, Bollywood movie stars have been taking part in waste clean-up activities at Versova beach.
Actress Abigail Pande told reporters she was surprised at the amount of waste she found.
女演员阿比盖尔·潘德（Abigail Pande ）告诉记者，她对自己找到的垃圾数量感到惊讶。
"I am having fun (cleaning this place). But it is also very sad because once I came here, I got to know that the amount of waste is so high that if you dig the ground four feet, you will still find plastic inside. And it will take years to properly clean the beach," Pande said.
Plastic has now been found in every corner of the world's oceans, from the bottom of the Pacific Mariana Trench to Antarctica.
In October, world governments will decide on a European Union proposal to create an Antarctic Ocean sanctuary. At 1.8 million square kilometers, the sanctuary would be the largest protected area on Earth.
I'm Phil Dierking.