The goal was to study where pollution in seven rivers flowing into Taihu Lake comes from and its severity. By looking at the elements in the sediments, they figured out which rivers were mostly polluted by cities, industries, or agriculture. Mashan, Liangxi, and Xiwan were hit by city pollution, Zhihu Port and Caoqiao by industry, and Dapu and Wujin by agriculture. The heavy metal pollution was worst from industries, then agriculture, with city pollution being the least concerning. This info can help figure out how to control heavy metal pollution in rivers near Taihu Lake.