This article from Science Daily produced by University of Basel
Mercury released into the atmosphere by industry enters the sea and from there makes its way into the food chain. Now, an analysis by the University of Basel has revealed how the harmful substance enters seawater in the first place. This is not primarily via rainfall, as previously assumed, but rather also involves gas exchange. Measures to reduce mercury emissions could therefore take effect faster than previously thought.
Every year, 2,000 metric tons of gaseous mercury are released into the atmosphere by coal-fired power stations and mining activities. The harmful substance then adopts various chemical forms as it circulates between the air, soil and water in a complex cycle. Mercury is particularly dangerous in the sea, where it accumulates in fish in the form of highly toxic methylmercury. When this compound enters the human body due to the consumption of fish, it can have an adverse effect on brain development in children and cause cardiovascular diseases in adults.
“It’s estimated that human activities have tripled the amount of mercury in the surface ocean since the onset of industrialization,” says the biogeochemist Martin Jiskra from the Department of Environmental Sciences at the University of Basel. Previously, experts assumed that mercury entered the ocean primarily via rainfall. “Those are just assumptions, however, as there are no collector stations for precipitation over the sea.”