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Large quantities of different heavy metals have been released to soils,water,or emitted to the air from various anthropogenic sources for long history,especially in the modern time.However,the transport patterns of these metals in our environment are different.By analysing historical distributions of the metals in dated lake sediment cores,their pollution processes can be assessed through time,and by comparing the locations of the sampled lakes,metal transport/dispersion patterns can be obtained.This work reports heavy metal distribution in lake sediment cores collected from different regions around world.The results show that lakes in urban or industrial areas can be contaminated by many kinds of heavy metals depending on local anthropogenic sources.Away from source areas,mercury as a global pollutant has shown considerable increase in the modern time sediments in all the lakes,demonstrating a global transport pattern.However,other metals can be transported locally or regionally through atmosphere,and show contamination in some relatively remote lakes,but not in a global scale.Lakes in some remote areas are still clean to many heavy metals except mercury.