The Yukon River has had a history of pollution from military installations, dumps, wastewater, and other sources. However, the Environmental Protection Agency does not list the Yukon River among its impaired watersheds, and water quality data from the U.S. Geological Survey shows relatively good levels of turbidity, metals, and dissolved oxygen. The Yukon and Mackenzie rivers have much higher suspended sediment concentrations than the great Siberian Arctic rivers.
The name Yukon, or ųųg han, is a contraction of the words in the Gwich'in phrase chųų gąįį han, which means white water river and refers to "the pale colour" of glacial runoff in the Yukon River. The contraction is Ųųg Han, if the /ųų/ remains nasalized, or Yuk Han, if there is no vowel nasalization. In 1843, the Holikachuks had told the Russian-American Company that their name for the river was Yukkhana and that this name meant big river. However, Yukkhana does not literally correspond to a Holikachuk phrase that means big river. Then, two years later, the Gwich'ins told the Hudson's Bay Company that their name for the river was Yukon and that the name meant white water river.White water river in fact corresponds to Gwich'in words that can be shortened to form Yukon. Because the Holikachuks had been trading regularly with both the Gwich'ins and the Yup'iks, the Holikachuks had been in a position to borrow the Gwich'in contraction and to conflate its meaning with the meaning of Kuigpak [River-big], which is the Yup'ik name for the same river. For that reason, the documentary evidence reflects that the Holikachuks had borrowed the contraction Ųųg Han [White Water River] from Gwich'in, and erroneously assumed that this contraction had the same literal meaning as the corresponding Yup'ik name Kuigpak [River-big].