According to the United Nations Environment Programme persistent organic pollutants (POPs) -despite being known for decades -are an increasing threat to humankind. They include anthropogenic molecules that, once entered, remain in the environment for a long time and get distributed around the world. Due to their hydrophobicity they accumulate in living organisms while being toxic not only to wildlife but also to us humans. For this reason the Stockholm Convention on Persistent Organic Pollutants or short just Stockholm Convention hosted by the United Nations was put into action in 2004 as an international measure against POPs. Among the twelve initial pollutants of concern are the so-called polychlorinated biphenyls (PCBs).