Harvard study examines mercury deposition throughout history

A Harvard study on environmental mercury deposition indicates that the toxic metal will continue to be prolific and in constant transfer in the environment, according to a Harvard press release.

Data on mercury emissions dating back to 2000 B.C. was incorporated into a model for mercury cycling, which factors in interactions between the land, ocean and atmosphere.  The researchers found the majority of mercury is eventually deposited in the ocean, where most water drains.

The vast majority of mercury emissions come from human sources.  According to the study, 60 percent of mercury in the atmosphere is from legacy mercury, historically released by humans.  Present day emissions account for 27 percent of atmospheric mercury and 13 percent of mercury in the atmosphere comes from natural sources.

Study authors said significant reduction in human output of mercury would help stabilize mercury levels.