How Mercury Gets into the Fish We Eat

Researchers from the Hebrew University in Jerusalem and the University of Nevada have discovered the mechanism whereby atmospheric mercury is transferred into marine organisms, and eventually into the food we eat.

The study, conducted by Prof. Menachem Luria from the Fredy and Nadine Herrmann Institute of Earth Sciences at the Hebrew University and Dr. Daniel Obrist of the University of Nevada, revealed that mercury's transformation from a passive to active state requires the presence of bromine. The Dead Sea was chosen as the ideal location for the study -despite the fact that there is no fish life in it- because of the high amounts of bromine released into the atmosphere in the region, the key component in the mercury oxidation process. 

"In the world generally, the amount of oxidized mercury in the atmosphere constitutes about one percent of all the mercury in the atmosphere," said Prof. Luria, "while above the Dead Sea the oxidized mercury often amounts up to about 50 percent."

To be exact, the amount of bromine found in the atmosphere above the Dead Sea is over 200 times that found in the average location- an irregularity possibly the result of the region's high temperatures. Although scientists have warned about the dangers mercury presents when eating fish for decades, the mechanism that converts atmospheric mercury into the active form found in marine life was previously unknown!