anchor: Sulfates are responsible for 6080 percent of total light extinction in the East, based on data collected during the 1990's in eastern national parks such as Acadia, Everglades, Great Smoky Mountains, Shenandoah, and in Washington, DC.
positive: There was data collected in the 1990s about sulfates and its role in light extinction.
negative: Sulfates play no role in light extinction according to a 1990s test.