Mercury’s falling, you say. And it is, but not in the way that you might expect. A new study sheds light on increasing levels of Hg in the atmosphere, and its effects on the food chain.
Mercury (Hg) is known to many of us as the forbidden fruit of the science lab, a substance that is dangerous to ingest. In its liquid form mercury is also known as quicksilver, since it has a tendency to form into tiny, glistening balls that run rapidly away from anything that touches them. These days, it’s having a party in the atmosphere.
Mercury In the Atmosphere
There is naturally mercury in the atmosphere. It comes from the soil, from the oceans, and from volcanic eruptions. However, the amount of mercury in the upper troposphere and lower stratosphere is rising. These days, the levels are likely two to three times higher than they were prior to the Industrial Revolution. The culprit? Coal, another material from the soil. Coal contains trace amounts of mercury, and when people process large amounts of it in coal-fired power plants, this mercury makes its way into the atmosphere.
In a study published December 19, 2011 in the journal Nature Geoscience, Seth Lyman and Daniel Jaffe from the University of Washington Bothell examinedhow interactions between the upper atmosphere and the earth are moving this mercury into the food chain.
Mercury Pollution Travels The World
Mercury is truly a global concern. While some pollution stays close to home, elemental mercury travels lightly and easily, tripping its way through the atmosphere. It can move around the globe several times before it finds a place to land. And when it lands, the mercury from coal burned half a world away can land on another continent, moving into the food chain there. According to Lyman and Jaffe’s research, areas such as the Southwestern United States seem to have conditions that make them especially prone to mercury deposition.
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