 Beginning in the 1930s, the city became known for the "Tacoma Aroma," a distinctive, acrid odor produced by pulp and paper manufacturing on the industrial tide flats.In the late 1990s, Simpson Tacoma Kraft reduced total sulfur emissions by 90%.This largely eliminated the problem; where once the odor was ever-present, it is now only noticeable occasionally downtown, primarily when the wind is coming from the east.