Lake Vänern exceeds the EU's regulated limit for selling, 6.5 picograms dioxin per gram of fish meat. This may seem like a very low level, but dioxin is one of the most dangerous toxins for the body, and is suspected to, for example, affect the brain, the nervous system and reproduction. It is also thought to cause cancer. Dioxin is in the herbacide Agent Orange, most famous for being used as a weapon in the Vietnam War.
Magnus Karlsson works at the IVL Swedish Environmental Research Institute's laboratory in Stockholm and is currently monitoring whitefish from the southern part of Lake Vänern.
"The aim is, of course, to give the fishing industry instructions and recommendations about which stocks should be fished and what time of year the levels are at their lowest," Karlsson told Swedish Radio News.