In scientific risk assessment, a major force to be encountered is public opinion. For many agents or environments, a previously established dogma exist which has settled in the mind of the public, the media and the scientists. Any risk evaluation that challenges this dogma, based on however good research, will be met with distrust, disliking and disdain. Examples are legion.

Galileo in 1613 challenged the concept regarding the structure of the Universe and was condemned and even put in prison. When the German Alfred Wegener in 1915 presented his theory on teutonic plates, the president of the American Geological Society commented "Utter, damned rot. If we are to believe in this hypothesis, we must forget everything we learned in the last seventy years and start all over again".

Today the same attitudes prevail. Anyone who challenges the concept of global warming is greeted with hostile comments, particularly by the media. If one claims that overnutrition is a far more important environmental health problem than air pollution, there is an outcry and suspicions that one is paid by the petroleum industry.

The role of research is to question established truths and beliefs. In order that society and environmental medicine can advance, this process must be undertaken irrespective of public opinion and politics. The results, even if diverse from existing dogma, must be taken seriously and objectively evaluated. A difficult but challenging task.