Selenium Levels in Environment Affect Health

What's special about selenium?

Selenium is a trace element that plays a vital role in the human body. The optimal intake, how­ever, is quite narrow: too much, and toxicity can result; too little, and deficiency symptoms may occur. Research has linked its harmful consequences to a range of conditions, including auto­immune diseases.

Environmental concentrations of selenium vary greatly. What are the consequences for human health?

The concentration of selenium in the soil varies significantly, depending on the parent rock and geographical location. This leads to variable selenium levels in plants, which can have an impact on our health through diet. But geographical location isn't the only factor that determines the amount of selenium in our food. For example, some foodstuffs are also fortified with selenium.

When did you discover your interest in geology?

I began collecting stones and shells and hunting for fossils as a child. At school, I was fascin­ated by the history of our planet. My favourite subjects were chemistry, geography and history; geology combines all those aspects. It was probably around this time that the seeds of my future career were planted.

You spent your childhood in the Netherlands. Did you move to Switzerland because of the mountains?

I've always been drawn to the mountains. When I was a student, I enjoyed going on field trips to alpine regions. Once I'd finished my studies in Utrecht, I was lucky enough to land an exciting research post in Switzerland. I still love heading for the mountains for summer hiking or the beautiful snowy winters.

You're attached to both ETH Zurich and Eawag. What kind of benefits does that bring?

Being a professor with a research group divided between the two institutions gives me and my team the opportunity to swap ideas with people from other backgrounds and with different expertise. It means we cover the full spectrum of research, from basic to applied.