In the Atmosphere, Mercury Changes Into a Soluble Form
How does the mercury get down to earth? In its elemental form, mercury can last for months in the atmosphere. Something is making it change from elemental to oxidized mercury, and exactly what causes the shift is an area that the scientists are still examining. Oxidized mercury moves quickly to the surface, and it is very soluble. Seth Lyman told Decoded Science, “Once oxidized mercury has been produced, it can be removed in clouds and rain or it can directly interact with surfaces and be taken up by chemical or physical interactions with those surfaces.” A combination of chemistry and weather determines what ecosystem will receive the inflow of mercury. It’s the luck of the draw, and the Southwestern United States happens to be less lucky than most.
Methylmercury Accumulates In The Food Chain
Once mercury hits the ground, it moves into soil and water. There, tiny bacteria convert it into methylmercury, a substance that accumulates in animals. Moving from plants into small animals and then into fish, the mercury accumulates up the food chain until it lands in top predators such as eagles, bears, and people. When it lands in these organisms, it can cause damage to the nervous system, endocrine system, and the kidneys. People who are exposed to too much mercury suffer from tremors, sensory impairment, and nervous system problems. Mercury exposure does not need to be acute for this to happen.
The Earth: One Connected System
Like climate change, atmospheric pollution brings home the idea that we live in one interconnected ecosystem. Although there are national boundaries, these boundaries don’t apply when it comes to the movements of wind and water and the pollutants that they carry with them. Research into the global movement of mercury reminds us that it is important to cultivate a global understanding of pollution and its consequences. If we do not, all of us, including those who had little hand in creating the pollution, will suffer the consequences.
Lyman, S., Jaffe, D. (2011). Formation and fate of oxidized mercury in the upper troposphere and lower stratosphere. Nature Geoscience. Accessed December 19, 2011.
Seth Lyman. Personal Interview. December 18, 2011.
US EPA. Mercury Exposure. Accessed December 20, 2011.Decoded Science