The health threat from mercury in freshwater fish could be blowing away in the wind


Mercury is one of the top 10 chemical concerns for public health according to the World Health Organization (WHO). In more than half of Swedish lakes the mercury levels are so high that eating the fish is a threat to the health of people and wildlife. To make matters worse, the problem seems to have no solution in sight. But new research gives hope: the mercury problem could very well be blowing away in the wind.

"Our research shows that Swedish freshwater fish might be on their way to becoming safe to eat in decades with current mercury pollution control measures, rather than in centuries as was previously believed", says Kevin Bishop, Swedish University of Agricultural Sciences (SLU), one of the researchers in the Swedish-Chinese-Swiss team behind the study.

After almost ten years of developing a sensitive technique to measure the movements of mercury gas between the atmosphere and landscape, the research group has published the first annual mass balance of mercury inputs and outputs for a peatland. While it is a major technical accomplishment just to have measured whether mercury gas is going into or out of the peatland 10 times a second for a year, the result of the mass balance is what is really remarkable.

"The first full year of measurements on a peatland showed that it is losing twice as much mercury gas back to the atmosphere as is being deposited on the peatland by the rain. This is a stunning finding because it means that recent reductions in atmospheric mercury concentrations (up to a 50 percent decrease in the last 20 years) have reversed the direction of mercury flows between the atmosphere and the peatland.", says Mats Nilsson, SLU.

Continue reading at Swedish University of Agricultural Sciences.

Image source:  Anders Asp SLU