Despite our great distance from the Arctic tundra, which is the site of contamination, the emissions from U.S. smokestacks have been polluting this region.  Toxins from the United States' air pollution have been carried to the Arctic by our weather patterns and a pattern of chemical travel known as the grasshopper effect.  The grasshopper effect is the effect of chemicals that evaporated or were put as emission into the air, where it travels with wind fronts moving north, until the front meets a cold front and the contaminants fall back down towards earth and out of the front.  Eventually these pollutants are evaporated again and move further north by traveling with wind fronts.  This process can continue over and over again until this pollution reaches the Arctic tundra. 

Among the chemicals that travel on the grasshopper effect is one that is known as  dioxin.  Toxins that are carried up to the Arctic have a slow breakdown rate, given the conditions in the Arctic, and so even toxins like toxaphene, which was banned from use in the United States decades ago, can still be found.  Studies have shown that certain toxic levels have been found to be six times higher in Inuit women than in southern Canadian women, which is due to the absorbing of the toxins into the Arctic food chain.  Another controversial study has traced the dioxin in the Arctic to an incinerator in Ames, Iowa, which is supposedly the "number one" contributor of dioxin to the Canadian tundra province of Nunavut.  Toxins like dioxin have been associated with learning disabilities, the disruption of hormones, and damaging of the immune system.  Due to this and the  discovery of toxins in their food chain, Inuits will have to adjust their diets from what they have always been eating or else risk the consequences of eating food containing toxins.  Recently a treaty has been signed by the United Nations to eventually eliminate several toxins, but until the treaty has been put into place, the people of the Arctic will continue to have to single out American air polluters.  Hopefully the Arctic tundra's toxicity levels will someday return to normal and life will continue on like it traditionally has in the Arctic, but until then the Inuit people will have to take precautions to prevent their consumption of toxins and the dangerous effects of toxins. 

            Another form of pollution that can be very damaging to the tundra is the pollution caused by the spilling of the contents of a pipeline into the tundra.  In the winter of 2001 a pipeline carrying oil and saltwater spilled open over the Alaskan tundra.  Surprisingly, the crude oil that was spilled over the tundra was not as much of a threat to the tundra as the saltwater was.  This is because while the oil only coats the tundra, the saltwater can actually penetrate the ground and make the tundra plants die, so that plants that would normally grow in the tundra could not grow there.  However, in this circumstance the oil that spilled out was hot enough that it melted some snow into water, and this snow diluted the salt in the saltwater so the mixture was not as dangerous to the tundra as straight saltwater.  The area was then after saturated with the salt that is dangerous to plants.  Some of the water that was created in the mixing reached a tundra pond that was in the area and it created an "oily sheen," which was lingering on the surface of the pond.  The area was to be cleaned out by being flushed through with fresh water and possibly a chemical that would clean the salt and oil from the tundra.  This pipeline spill came at a bad time for oil companies, who were attempting to convey a positive look about their environmental record so that they could get the Arctic National Wildlife Refuge open for their business.  The oil company that suffered the spill, Phillips, had argued that the north slope of the refuge could be used for oil drilling without much risk to the reserve, but this spill shows that spilled oil is not the only risk of oil drilling.  Hopefully further action will occur someday to prevent the risks of oil drilling so that more spills could no longer harm the environment.