Study shows three times more mercury in upper ocean since Industrial Revolution

A press release from the Woods Hole Oceanographic Institute: Although the days of odd behavior among hat makers are a thing of the past, the dangers mercury poses to humans and the environment persist today.

Mercury is a naturally occurring element as well as a by-product of such distinctly human enterprises as burning coal and making cement. Estimates of "bioavailable" mercury—forms of the element that can be taken up by animals and humans—play an important role in everything from drafting an international treaty designed to protect humans and the environment from mercu
ry emissions, to establishing public policies behind warnings about seafood consumption.

Yet surprisingly little is known about how much mercury in the environment is the result of human activity, or even how much bioavailable mercury exists in the global ocean. Until now.

A new paper by a group that includes researchers from the Woods Hole Oceanographic Institution (WHOI), Wright State University, Observatoire Midi-Pyréneés in France, and the Royal Netherlands Institute for Sea Research appears in this week's edition of the journal Nature and provides the first direct calculation of mercury in the global ocean from pollution based on data obtained from 12 sampling cruises over the past 8 years. The work, which was funded by the U.S. National Science Foundation and the European Research Council and led by WHOI marine chemist Carl Lamborg, also provides a look at the global distribution of mercury in the marine environment.

"It would seem that, if we want to regulate the mercury emissions into the environment and in the food we eat, then we should first know how much is there and how much human activity is adding every year," said Lamborg, who has been studying mercury for 24 years. "At the moment, however, there is no way to look at a water sample and tell the difference between mercury that came from pollution and mercury that came from natural sources. Now we have a way to at least separate the bulk contributions of natural and human sources over time."...

Bohr model of mercury, author unknown, Wikimedia Commons, under the Creative Commons 2.0 license