Researchers from the University of Magallanes and the University of North Texas in the US took samples over 10 days from a number of rivers and other sources of fresh water in the area.
"Our results confirm that these waters are clean, the cleanest on this planet," said University of North Texas scientist Guido Verbeck.
"The instruments we used to study the samples can detect two parts of chemicals per every million parts of water, and here they detected nothing," he said.
Puerto Williams is located at 3,551 km south of Santiago at the country's extreme southern tip.
According to Ricardo Rozzi, director of the Antarctic Biocultural Conservation Program, the area "is like something out of the movie 'Jurassic Park'," because "the air and water have a purity and an ecosystem that existed before the Industrial Revolution".
The study indicates that extremely pure water has also been found in Torres del Paine National Park, also in Chile's Magallanes region, as well as in southeastern China, western Australia and Upstate New York.
According to Rozzi, the result of the research is very relevant because fresh water is a very scarce asset and also because it identifies the Cabo de Hornos reserve as a "natural laboratory" suitable for many kinds of research projects.
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