Introduced plant and animal species can create ecological desasters. Alien species have already been found in many parts of the polar regions, including Antarctica. In more recent times, the highest risk of introduction is use of contaminated boots that have been used elsewhere, possibly in climatically comparable high mountain or polar areas.
In 2008, scientists have tested boots of 260 visitors at the airport in Longyearbyen and found 500 moss fragments and 1000 seeds of 52 plant species, including many birch seeds.
Not just a rubber boot, but a potentially dangerous source of contamination