Interview of Lars-Éric Heimbürger-Boavida, MIO-CEM, in the Parisien newspaper: "high concentrations of mercury in Arctic animals and their human consumers

The presence of mercury in the oceans and one of its most harmful forms for living beings is a major part of the scientist's research, and he participated in an expedition to the Arctic.

What role has the Axa Research Fund played in your work?

Thanks to this funding, I spent four months in the Arctic Ocean in the summer of 2015. I participated in a research expedition on the German icebreaker Polarstern. It was not only the experience of a lifetime, but also led to significant scientific advances on mercury, sea ice, and marine sediments. As a follow-up to the fellowship, in 2017 I organized an exhibition of photos from the Arctic expeditions, gave public seminars, and measured mercury levels in participants' hair to inform them of their individual exposure.

Why are you interested in the different kinds of mercury found in water?

Mercury is a naturally occurring element that is found everywhere in the earth's crust, through forest fires or volcanic emissions. But there is ten times more in the atmosphere due to human activities. However, we do not know today where the mercury we find in the ocean comes from and how it is transformed into its most dangerous form that can affect our health, methylmercury. When ingested, it becomes concentrated in some of the fish we eat.

What are the first results of your research?

According to my work in the Arctic Ocean, methylmercury is produced at a depth of 100 m, compared to 1,000 m in the Atlantic Ocean. We have also been able to show that the loss of old multi-year sea ice due to global warming is leading to globally higher levels of methylmercury in the cryosphere (all parts of the earth where water is present in a solid state). Both phenomena contribute to high mercury concentrations in Arctic animals and their human consumers