In Florida, the thunderstorms rain down mercury

It is estimated that several thousand tons of mercury are released into the atmosphere every year, from both natural and man-made sources.  

A new study by Dr. Christopher Holmes from the Department of Earth, Ocean and Atmospheric Sciences at Florida State University, has found that a lot of that harmful mercury is finding its way back down to earth and into various ecosystems by way of thunderstorms.  

The researchers found that rain gathered from thunderstorms has 50% higher concentrations of mercury than rain from regular storms. The reason is that thunderstorm clouds are about 15 kilometres thick, compared to only a few kilometres thick for regular storm clouds.  

The scientists will now try to understand why there is more mercury at higher altitudes, and how it can affect people and wildlife, particularly in areas with higher instances of thunderstorms such as the Southeast United States.

Additional Links:

• Paper in Environmental Science & Technology: Thunderstorms Increase Mercury Wet Deposition 
• Phys.org: Thunderstorms spread mercury pollution