In April 2004, as discussions reached a conclusion on the new European Community regulation on chemicals and their safe use (EC 1907/2006), dealing with the Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH), the WWF publicized the results of blood tests on thirty-nine European Members of Parliament (MPs) who were not exposed to any particular chemical pollutants. No fewer than 76 persistent toxic chemical substances were found in their blood, out of the 101 for which they had been tested. On average, each MP carried a cocktail of forty-one toxic products composed of substances that were persistent (not biodegradable) and bio-accumulative (that accumulate in the body). Thirteen chemical residues (phtalates, perfluorinated components) were systematically found in all the MPs' blood samples.

Since the early 1990s, revealing the systematic presence of toxic chemical substances in each individual's body and measuring the ‘toxic body burden’ has become one of the main means of action for activist organizations like the WWF. But the toxic body burden is more than that; it has also become a research subject for public health specialists, doctors, toxicologists and biologists increasingly interested in the effects of substances present almost permanently in human bodies. Surveys highlighting the increasing contamination of human bodies are also undertaken by government institutions such as the US Center for Disease Control (CDC), which has set up programmes that regularly measure and publish results confirming the presence of numerous chemical contaminants in human bodies.