The international significance of research into the sources, behaviour, fate, and effects of persistent organic pollutants (POPs) is exemplified by the Stockholm Convention for which the host organisation is the United Nations Environment Programme (UNEP). Following extensive negotiation, it was adopted on 22 May 2001, entered into force 90 days after the 50th party had ratified it on 17 May 2004, and by late 2008 there were over 180 participants (http://chm.pops.int/). The objective of the Convention is ‘to protect human health and the environment from persistent organic pollutants’ Among other things, it recognises the need for global action in recognition of the facts that POPs are toxic, resistant to degradation, and bioaccumulative. Furthermore, they are capable of global transport via air, water, and migratory species, and are deposited far from their place of release, where they accumulate in terrestrial and aquatic ecosystems.